[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and la...[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.展开更多
[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medi...[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.展开更多
Harmful algal blooms(HABs) have led to extensive ecological and environmental issues and huge economic losses.Various HAB control techniques have been developed,and biological methods have been paid more attention.Alg...Harmful algal blooms(HABs) have led to extensive ecological and environmental issues and huge economic losses.Various HAB control techniques have been developed,and biological methods have been paid more attention.Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner,and kill or damage the algal cells.A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp.The culture conditions were optimized using a single-factor test method.Factors including carbon source,nitrogen source,temperature,initial pH value,rotational speed and salinity were studied.The results showed that the cultivation of the bacteria at 28℃ and 180 r min-1with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46.The optimal medium composition for strain DH46 was determined by means of uniform design experimentation,and the most important components influencing the cell density were tryptone,yeast extract,soluble starch,NaNO3 and MgSO4.When the following culture medium was used(tryptone 14.0g,yeast extract 1.63g,soluble starch 5.0 g,NaNO3 1.6 g,MgSO4 2.3 g in 1L),the largest bacterial dry weight(7.36 g L-1) was obtained,which was an enhancement of 107% compared to the initial medium;and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.展开更多
The production of ligninolytic enzymes and protease by Phanerochaete chrysosporium was investigated under different culture conditions. Different amounts of medium were employed in free and immobilized culture, togeth...The production of ligninolytic enzymes and protease by Phanerochaete chrysosporium was investigated under different culture conditions. Different amounts of medium were employed in free and immobilized culture, together with two kinds of medium with different C/N ratios. Little lignin peroxidase （LIP） （〈 2 U/L） was detected in free culture with nitrogen-limited medium （C/N ratio： 56/2.2, in mmol/L）, while manganese peroxidase （MnP） maximum activity was 231 and 240 U/L in 50 and 100 ml medium culture, respectively. Immobilized culture with 50 ml nitrogen-limited medium gave the highest MnP and LiP production with the maximum values of 410 and 721 U/L separately on the day 5; however, flasks containing 100 ml nitrogen-limited medium only produced less MnP with a peak value of 290 U/L. Comparatively, carbon-limited medium （C/N ratio： 28/44, in mmol/L） was adopted in culture but produced little MnP and LiE Medium type had the greatest impact on protease production. Large amount of protease was produced due to glucose limitation. Culture type and medium volume influence protease activity corporately by affecting oxygen supply. The results implied shallow immobilized culture was a possible way to gain high production of ligninolytic enzymes.展开更多
The effects of temperature, initial pH, salinity of culture medium, and carbon and nitrogen sources on growth and doco- sahexaenoic acid (C22 : 6 n-3, DHA) production from Schizochytrium limacinum OUC88 were investiga...The effects of temperature, initial pH, salinity of culture medium, and carbon and nitrogen sources on growth and doco- sahexaenoic acid (C22 : 6 n-3, DHA) production from Schizochytrium limacinum OUC88 were investigated in the present study. The results revealed that the optimal temperature, initial pH and salinity level of the medium for DHA production were 23℃, 7.0 and 18, respectively. Glucose was proved the best carbon source for the growth and DHA production from S. limacinum. Among the nitrogen sources tested, soybean cake hydrolysate, a cheap by-product, was found to be effective for the accumulation of DHA in S. lima- cinum cells. In addition, increasing the concentration of carbon sources in the medium caused a significant increase in cell biomass; however, accumulation of DHA in cells was mainly stimulated by the ratio of C/N in the medium. Under the optimal culture condi- tions, the maximum DHA yield achieved in flasks was 4.08 g L-1 after 5 d of cultivation.展开更多
Strain of Flavobacterium sp.(S-9801),was screened from 207 strains of marine bacteria isolated from the Bohai Sea continental shelf and the Zhujiang Estuary,for its red pigment production.The biological characteristic...Strain of Flavobacterium sp.(S-9801),was screened from 207 strains of marine bacteria isolated from the Bohai Sea continental shelf and the Zhujiang Estuary,for its red pigment production.The biological characteristics of strain S-9801 and culture conditions of pigment production have been checked out in this study. The color of the bacterial colony on 2216E medium was from coccineus to rose bengal. Optimum culture conditions were sodium chloride concentration(g/dm3),10～30;pH,3～8;temperature,25～28℃;tryptone and yeast extract as nitrogen sources and glucose as carbon source. Under optimum conditions,pigment accumulation started after 12 h,reaching a maximum rate of synthesis at 36 h.展开更多
The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditi...The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditions （temperature, pH, and inoculum） on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% （v/v） in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.展开更多
Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In th...Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In this study, we optimized the production of a recombinant ALF by expressing E. sinensis ALF genes in Eseherichia coli maintained in shake-flasks. In particular, we focused on optimization of both the medium composition and the culture condition. Various medium components were analyzed by the Plackett-Burman design, and two significant screened factors, （NH4）2SO4 and KH2PO4, were further optimized via the central composite design （CCD）. Based on the CCD analysis, we investigated the induction start-up time, the isopropylthio-D-galactoside （IPTG） concentration, the post-induction time, and the temperature by response surface methodology. We found that the highest level of ALF fusion protein was achieved in the medium containing 1.89 g/L （NH4）2SO4 and 3.18 g/L KH2PO4, with a cell optical density of 0.8 at 600 nm before induction, an IPTG concentration of 0.5 mmol/L, a post-induction temperature of 32.7~C, and a post-induction time of 4 h. Applying the whole optimization strategy using all optimal factors improved the target protein content from 6.1% （without optimization） to 13.2%. We further applied the optimized medium and conditions in high cell density cultivation, and determined that the soluble target protein constituted 105% of the total protein. Our identification of the economic medium composition, optimal culture conditions, and details of the fermentation process should facilitate the potential application of ALF for further research.展开更多
We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphoma...We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphomas of B cell type. The culture cells were pretreated with or without galactose oxi-dase (GO) prior to plating. Colony growth was best supported with BCGF. A moderate increment was observed with rIL-3, as well as rIL-1β and even to a lesser degree, by rlL-2, while B cell stimulating factor-2 (rBCSF-2) and rlL-1β did not show significant activity. rGM-CSF and rG-CSF had little effect, while rM-CSF enhanced the formation of lymphoma colonies. The cells from different patients had different requirements for Staphylococcus aureus protein A and GO pretreatment. It reflected the differences in activation and differentiation status and surface properties of lymphoma cells from different patients. The cells from CSF of one patient were successfully maintained in serum-free culture medium supplemented with 10% BCGF or 5% PHA-LCM for more than 4 months. The long-term culture cells were EBV negative, phenotypically consistent with B cells and gene rearrangements for JH, Kappa and myc. This serum-free culture system allowed extensive analysis of the growth requirements for clonogenic precursors.展开更多
The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cul- tured on different media at different temperatures under natura...The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cul- tured on different media at different temperatures under natural light for inducing conidia to explore the optimum isolation technique of single spore and optimum cul- ture condition of conidia. The results showed that the successful isolating rate of single spore from yellow rice false smut balls reached 90.00%. The sporulatina quantities of isolated single spores cultured on PSD and PDB media at 22 -29 ~C （variable temperature under natural light） or 28 ℃ （constant temperature under dark condition） for 12 d were up to 6.3× 107 and 1.1× 106 spore/mL, respectively. PSA was the most effective method to isolate single spores from yellow rice false smut balls of U. virens. The optimum conidia culture condition included PSD or PDB medium, 22 -29℃ or 28℃, natural light and vibration culture. Key words Ustilaginoidea virens; Single spore isolation; Conidia; Culture condition展开更多
Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain...Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain.The number of viable bacteria of strain 4-3 in this study was the evaluation index,and the culture conditions of the liquid fermentation were optimized by single factor experiment.The optimized culture condition was as follows:incubating temperature 32°C,initial pH value 7.2,rotation speed 220 r/min,inoculum concentration 3%and incubating 56 h,under which higher concentrations of Bacillus amyloliquefaciens could be obtained.展开更多
Arctic sea ice in the polar region provides a cold habitat for microbial community. Arctic sea ice microorganisms are revealed to be of considerable importance in basic research and potential in biotechnological appli...Arctic sea ice in the polar region provides a cold habitat for microbial community. Arctic sea ice microorganisms are revealed to be of considerable importance in basic research and potential in biotechnological application. This paper investigated the culture condition and extraceIlular hydrolase of 14 strains of different Arctic sea ice bacteria. The results showed that optimal growth temperature of strains is 15 ℃ or 20 ℃. The optimal pH is about 8.0. They hardly grow at acid condition. 3 % NaCl is necessary for better growth. These strains have different abilities in producing amylase, protease, eellulase and lipase. Pseudoalteronomas sp. Bsi429 and Pseudoalteronomas sp. Bsi539 produced both cellulose, protease and lipase. These results provide a basis for further developing and exploiting the cold adapted marine enzyme resources.展开更多
Streptomyces caelestis FAS is an actinomyces strain isolated with Ustilago scitaminea as an indicator. With GAUZE s medium as the basic medium, carbon source and nitrogen source in the medium and ventilation volume we...Streptomyces caelestis FAS is an actinomyces strain isolated with Ustilago scitaminea as an indicator. With GAUZE s medium as the basic medium, carbon source and nitrogen source in the medium and ventilation volume were optimized, and the antifungal substances produced by S. caelestis FAS were preliminarily determined through organic solvent extraction and ammonium sulfate precipitation. The results showed that the antifungal components produced by S. caelestis FAS were proteins, and the optimal culture conditions were using corn flour as carbon source and KNO 3 as nitrogen source and culturing in 250 ml triangular flask added with 70 ml of culture medium. The crude protein obtained under these culture conditions had the best antifungal effect with an inhibition zone diameter of 25 mm. This study will provide a scientific basis for further study on the antifungal mechanism and application of S. caelestis FAS.展开更多
[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Na...[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen（N）, phosphorus（P）, iron（Fe）, silicon（ Si ） and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows： the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment.展开更多
The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain ,Aspergillusfoetidus ZU-GI in solid-state fermentation （SSF）. Certain fermentation parameters involving mo...The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain ,Aspergillusfoetidus ZU-GI in solid-state fermentation （SSF）. Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 ℃ incubation temperature, 18^h cultivation period of seed, 10% inoculum volume, 5.0-6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2037.51 U/g dry matter near the 144th hour of fermentation.展开更多
[Objective] Brevibacil us laterosporus BL-21 was inhibitory to Gibberel a sanbinetti, Fusarium graminearum Magnaporthe grisea and many other phy-topathogenic fungi. Antimicrobial substances can be increased through op...[Objective] Brevibacil us laterosporus BL-21 was inhibitory to Gibberel a sanbinetti, Fusarium graminearum Magnaporthe grisea and many other phy-topathogenic fungi. Antimicrobial substances can be increased through optimizing the medium of Brevibacil us laterosporus. [Method] A total of 10 factors were tested for their function of improving antibiotics yield of BL-21 by single-factor test. And the indicative bacterium was screened. [Result] The best indicative bacterium was Al-ternaria solani, the optimum process parameters in shaking flask on fermentation consisted of initial pH of 8.0, culture at 30 ℃, loadage 90 ml/250 ml, rotation 180 r/min, and fermentation time of 48 h. The results also indicated that glucose was the best carbon source for the antibiotics productivity of BL-21, and beef extract was the best nitrogen source. In addition, univalent ion Cl＋ and divalent ion Mn2＋ stimu-lated BL-21 antibacterial active component biosynthesis. [Conclusion] Optimized medi-um is more conducive to produce antimicrobial substances.展开更多
Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To deter...Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells, primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum. The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25℃.展开更多
Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy （SEM） and sequence comparisons of two segments of genes （small ribosomal subunit and large s...Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy （SEM） and sequence comparisons of two segments of genes （small ribosomal subunit and large subunit of Rubisco）, the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm （OD680） under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates （RGR） peaked at the highest tested level （0.25 mmol/L）. The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.展开更多
The focus of this research lies in community empowerment based on culture and local communities as well as sustainable ecotourism,which is directed at a complicated mechanism of empowerment elements,local culture that...The focus of this research lies in community empowerment based on culture and local communities as well as sustainable ecotourism,which is directed at a complicated mechanism of empowerment elements,local culture that is thick in ecotourism to get added value for the novelty of ecotourism research.The object of research is Wasur National Park(WNP),Papua,Indonesia.Qualitative methods have been used to obtain accurate data and information,i.e.,in-depth interviews with indigenous people to find out the benefits or functions of their culture that can be developed in ecotourism,interviews with leaders and staff of WNP and the Department of Culture and Tourism to find out the potential and processes empowerment and existing tourism potential.As a result,from the perspective of empowerment,local people will easily follow the empowerment process provided that they use methods that are culturally appropriate which is from the viewpoints from the culture of sasi,totem and sacred places.The culture adopted by the community is in accordance with the principles of ecotourism that supports sustainability,environmental conservation,protection of environmental resources and increases economic value.However,it is recommended to carry out modified socialization in accordance with the current conditions.Hence,tourists who visit WNP do not become afraid of the very rigid sanctions which are applied to them who violate the existing cultural and environmental customs.Moreover,to get added economic value in the tourism business within WNP,it is necessary to explore the potential of cultural wealth,natural and biological wealth so that it becomes the main attraction in carrying out the economic empowerment of local communities in the field of ecotourism.展开更多
Objective: To explore the mechanism of neurotropism in peripheral nerve regeneration by assessing the bioactivity of regeneration microcircumstance on motoneurons. Methods The motor branch Of femoral nerve to quadrice...Objective: To explore the mechanism of neurotropism in peripheral nerve regeneration by assessing the bioactivity of regeneration microcircumstance on motoneurons. Methods The motor branch Of femoral nerve to quadriceps was incised and the distal stump was sutured with one-end silicone chamber. The nerve regeneration chamber fluids from distal motor nerve stumps (motor branch of femoral nerve ) (MD-NRCF) was collected 7d post-operatively, and with the same method, nerve regeneration conditioned fluids from distal stumps nerve stumps (saphenous nerve ) (SD-NRCF) was collected. The dissociated rat’s motoneurons were co-cultured with MD-NRCF, SD-NRCF, basic fibroblast growth factor (b-FGF) and serum-free medium for 72h respectively and then were photographed under phase-contrast microscope. The longest neurites and cellbody areas of motoneurons from each group were measured by cell image processing computer system. MTT colorimetric assay was also used to measure cell activation. Results The cells of MD-NRCF group had significantly longer neurites than the other 3 groups, and their activation was also superior to those of the other groups. Conclusion These results indicate that MD-NRCF has more significant neurite-promoting and neurobiological effects on motoneuron than SD-NRCF and b-FGF.展开更多
基金Supported by the National Natural Science Foundation of China(30771596)~~
文摘[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.
文摘[Objective] The paper was to explore the effect of different culture conditions on sporulation quantity of Phytophthora capsici in Capsicum annuum L.var.dactylus M.in Xunhua.[Method] The effects of light hours,pH,medium and temperature on sporulation quantity during isolation and culture process of P.capsici were studied.[Result] The sporulation quantity of P.capsici under the conditions of 24 h/day light,pH 7.0,potato medium（PSA） and 30 ℃ was the largest,and pH,basal medium and temperature had greater impact on sporulation quantity.[Conclusion]The study laid foundation for the study on natural incidence condition of C.annuum in Xunhua.
基金financially supported by the National Natural Science Foundation(40930847,31070442)the Natural Science Foundation of Fujian Province(2012J01150)Public science and technology research funds projects of ocean(201305016,201305041,201305022) and MELRI1003
文摘Harmful algal blooms(HABs) have led to extensive ecological and environmental issues and huge economic losses.Various HAB control techniques have been developed,and biological methods have been paid more attention.Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner,and kill or damage the algal cells.A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp.The culture conditions were optimized using a single-factor test method.Factors including carbon source,nitrogen source,temperature,initial pH value,rotational speed and salinity were studied.The results showed that the cultivation of the bacteria at 28℃ and 180 r min-1with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46.The optimal medium composition for strain DH46 was determined by means of uniform design experimentation,and the most important components influencing the cell density were tryptone,yeast extract,soluble starch,NaNO3 and MgSO4.When the following culture medium was used(tryptone 14.0g,yeast extract 1.63g,soluble starch 5.0 g,NaNO3 1.6 g,MgSO4 2.3 g in 1L),the largest bacterial dry weight(7.36 g L-1) was obtained,which was an enhancement of 107% compared to the initial medium;and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.
基金This work was supported by the National Natural Science Foundation of China(No.50478010).
文摘The production of ligninolytic enzymes and protease by Phanerochaete chrysosporium was investigated under different culture conditions. Different amounts of medium were employed in free and immobilized culture, together with two kinds of medium with different C/N ratios. Little lignin peroxidase （LIP） （〈 2 U/L） was detected in free culture with nitrogen-limited medium （C/N ratio： 56/2.2, in mmol/L）, while manganese peroxidase （MnP） maximum activity was 231 and 240 U/L in 50 and 100 ml medium culture, respectively. Immobilized culture with 50 ml nitrogen-limited medium gave the highest MnP and LiP production with the maximum values of 410 and 721 U/L separately on the day 5; however, flasks containing 100 ml nitrogen-limited medium only produced less MnP with a peak value of 290 U/L. Comparatively, carbon-limited medium （C/N ratio： 28/44, in mmol/L） was adopted in culture but produced little MnP and LiE Medium type had the greatest impact on protease production. Large amount of protease was produced due to glucose limitation. Culture type and medium volume influence protease activity corporately by affecting oxygen supply. The results implied shallow immobilized culture was a possible way to gain high production of ligninolytic enzymes.
文摘The effects of temperature, initial pH, salinity of culture medium, and carbon and nitrogen sources on growth and doco- sahexaenoic acid (C22 : 6 n-3, DHA) production from Schizochytrium limacinum OUC88 were investigated in the present study. The results revealed that the optimal temperature, initial pH and salinity level of the medium for DHA production were 23℃, 7.0 and 18, respectively. Glucose was proved the best carbon source for the growth and DHA production from S. limacinum. Among the nitrogen sources tested, soybean cake hydrolysate, a cheap by-product, was found to be effective for the accumulation of DHA in S. lima- cinum cells. In addition, increasing the concentration of carbon sources in the medium caused a significant increase in cell biomass; however, accumulation of DHA in cells was mainly stimulated by the ratio of C/N in the medium. Under the optimal culture condi- tions, the maximum DHA yield achieved in flasks was 4.08 g L-1 after 5 d of cultivation.
文摘Strain of Flavobacterium sp.(S-9801),was screened from 207 strains of marine bacteria isolated from the Bohai Sea continental shelf and the Zhujiang Estuary,for its red pigment production.The biological characteristics of strain S-9801 and culture conditions of pigment production have been checked out in this study. The color of the bacterial colony on 2216E medium was from coccineus to rose bengal. Optimum culture conditions were sodium chloride concentration(g/dm3),10～30;pH,3～8;temperature,25～28℃;tryptone and yeast extract as nitrogen sources and glucose as carbon source. Under optimum conditions,pigment accumulation started after 12 h,reaching a maximum rate of synthesis at 36 h.
文摘The production of cellulase in Bacillus amyloliquefaciens UNPDV-22 was optimized using response surface methodology （RSM）. Central composite design （CCD） was used to study the interactive effect of culture conditions （temperature, pH, and inoculum） on cellulase activity. Results suggested that temperature and pH all have significant impact on cellulase production. The use of RSM resulted in a 96% increase in the cellulase activity over the control of non-optimized basal medium. Optimum cellulase production of 13 U/mL was obtained at a temperature of 42.24 ℃, pH of 5.25, and inoculum size of 4.95% （v/v） in a fermentation medium containing wheat bran, soybean meal and malt dextrin as major nutritional factors.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2006AA100311)
文摘Anti-lipopolysaccharide factors （ALFs） are important antimicrobial peptides that are isolated from some aquatic species. In a previous study, we isolated ALF genes from Chinese mitten crab, Eriocheir sinensis. In this study, we optimized the production of a recombinant ALF by expressing E. sinensis ALF genes in Eseherichia coli maintained in shake-flasks. In particular, we focused on optimization of both the medium composition and the culture condition. Various medium components were analyzed by the Plackett-Burman design, and two significant screened factors, （NH4）2SO4 and KH2PO4, were further optimized via the central composite design （CCD）. Based on the CCD analysis, we investigated the induction start-up time, the isopropylthio-D-galactoside （IPTG） concentration, the post-induction time, and the temperature by response surface methodology. We found that the highest level of ALF fusion protein was achieved in the medium containing 1.89 g/L （NH4）2SO4 and 3.18 g/L KH2PO4, with a cell optical density of 0.8 at 600 nm before induction, an IPTG concentration of 0.5 mmol/L, a post-induction temperature of 32.7~C, and a post-induction time of 4 h. Applying the whole optimization strategy using all optimal factors improved the target protein content from 6.1% （without optimization） to 13.2%. We further applied the optimized medium and conditions in high cell density cultivation, and determined that the soluble target protein constituted 105% of the total protein. Our identification of the economic medium composition, optimal culture conditions, and details of the fermentation process should facilitate the potential application of ALF for further research.
文摘We developed a serum-free culture system that promoted the growth of B cell colonies in peripheral blood, bone marrow, lymph nodes and cerebrospinal fluid (CSF) from 7 out of 8 patients with non-Hodgkin's lymphomas of B cell type. The culture cells were pretreated with or without galactose oxi-dase (GO) prior to plating. Colony growth was best supported with BCGF. A moderate increment was observed with rIL-3, as well as rIL-1β and even to a lesser degree, by rlL-2, while B cell stimulating factor-2 (rBCSF-2) and rlL-1β did not show significant activity. rGM-CSF and rG-CSF had little effect, while rM-CSF enhanced the formation of lymphoma colonies. The cells from different patients had different requirements for Staphylococcus aureus protein A and GO pretreatment. It reflected the differences in activation and differentiation status and surface properties of lymphoma cells from different patients. The cells from CSF of one patient were successfully maintained in serum-free culture medium supplemented with 10% BCGF or 5% PHA-LCM for more than 4 months. The long-term culture cells were EBV negative, phenotypically consistent with B cells and gene rearrangements for JH, Kappa and myc. This serum-free culture system allowed extensive analysis of the growth requirements for clonogenic precursors.
基金Science and Technology Project of Guizhou Province[QKH Major Project( 2012 ) 6012 ]Supported by Science and Technology Fund of Guizhou Province ( QKH J[2009]2103)+1 种基金Science and Technology Research Programof Guizhou Province ( QKH NY[2012]3031)Project of Guizhou Academy of Agricultural Sciences ( [2010]033 and QNKH[Major]07016)
文摘The single spores were isolated from chlamydospores of Ustilaginoidea virens with three different maturities by PSA. The isolated single spores were cul- tured on different media at different temperatures under natural light for inducing conidia to explore the optimum isolation technique of single spore and optimum cul- ture condition of conidia. The results showed that the successful isolating rate of single spore from yellow rice false smut balls reached 90.00%. The sporulatina quantities of isolated single spores cultured on PSD and PDB media at 22 -29 ~C （variable temperature under natural light） or 28 ℃ （constant temperature under dark condition） for 12 d were up to 6.3× 107 and 1.1× 106 spore/mL, respectively. PSA was the most effective method to isolate single spores from yellow rice false smut balls of U. virens. The optimum conidia culture condition included PSD or PDB medium, 22 -29℃ or 28℃, natural light and vibration culture. Key words Ustilaginoidea virens; Single spore isolation; Conidia; Culture condition
文摘Bacillus amyloliquefaciens 4-3 is an excellent plant endophyte that can be used as a good raw material for microecological preparations.For this reason,it is important to optimize the culture conditions of this strain.The number of viable bacteria of strain 4-3 in this study was the evaluation index,and the culture conditions of the liquid fermentation were optimized by single factor experiment.The optimized culture condition was as follows:incubating temperature 32°C,initial pH value 7.2,rotation speed 220 r/min,inoculum concentration 3%and incubating 56 h,under which higher concentrations of Bacillus amyloliquefaciens could be obtained.
文摘Arctic sea ice in the polar region provides a cold habitat for microbial community. Arctic sea ice microorganisms are revealed to be of considerable importance in basic research and potential in biotechnological application. This paper investigated the culture condition and extraceIlular hydrolase of 14 strains of different Arctic sea ice bacteria. The results showed that optimal growth temperature of strains is 15 ℃ or 20 ℃. The optimal pH is about 8.0. They hardly grow at acid condition. 3 % NaCl is necessary for better growth. These strains have different abilities in producing amylase, protease, eellulase and lipase. Pseudoalteronomas sp. Bsi429 and Pseudoalteronomas sp. Bsi539 produced both cellulose, protease and lipase. These results provide a basis for further developing and exploiting the cold adapted marine enzyme resources.
基金Supported by Natural Science Foundation of China(31471555)Special Fund for Basic Scientific Research of Central Nonprofit Research Institutes(1630052016010)The Earmarked Fund for Modern Agro-industry(Sugar Crop Industry)Technology Research System(CARS-170301)
文摘Streptomyces caelestis FAS is an actinomyces strain isolated with Ustilago scitaminea as an indicator. With GAUZE s medium as the basic medium, carbon source and nitrogen source in the medium and ventilation volume were optimized, and the antifungal substances produced by S. caelestis FAS were preliminarily determined through organic solvent extraction and ammonium sulfate precipitation. The results showed that the antifungal components produced by S. caelestis FAS were proteins, and the optimal culture conditions were using corn flour as carbon source and KNO 3 as nitrogen source and culturing in 250 ml triangular flask added with 70 ml of culture medium. The crude protein obtained under these culture conditions had the best antifungal effect with an inhibition zone diameter of 25 mm. This study will provide a scientific basis for further study on the antifungal mechanism and application of S. caelestis FAS.
基金Supported by National Basic Research Program of China(973 Pro-gram)(2003CB71600)~~
文摘[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen（N）, phosphorus（P）, iron（Fe）, silicon（ Si ） and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows： the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment.
文摘The work is intended to achieve optimum culture conditions of α-galactosidase production by a mutant strain ,Aspergillusfoetidus ZU-GI in solid-state fermentation （SSF）. Certain fermentation parameters involving moisture content, incubation temperature, cultivation period of seed, inoculum volume, initial pH value, layers of pledget, load size of medium and period of cultivation were investigated separately. The optimal cultivating conditions of α-galactosidase production in SSF were 60% initial moisture of medium, 28 ℃ incubation temperature, 18^h cultivation period of seed, 10% inoculum volume, 5.0-6.0 initial pH of medium, 6 layers of pledget and 10 g dry matter loadage. Under the optimized cultivation conditions, the maximum α-galactosidase production was 2037.51 U/g dry matter near the 144th hour of fermentation.
基金Supported by National Natural Science Foundation of China(31370511)Natural Science Foundation of Heilongjiang Province(C201203)Open Fund of Key Laboratory of Microbiology of Heilongjiang University(2012MOI-1)~~
文摘[Objective] Brevibacil us laterosporus BL-21 was inhibitory to Gibberel a sanbinetti, Fusarium graminearum Magnaporthe grisea and many other phy-topathogenic fungi. Antimicrobial substances can be increased through optimizing the medium of Brevibacil us laterosporus. [Method] A total of 10 factors were tested for their function of improving antibiotics yield of BL-21 by single-factor test. And the indicative bacterium was screened. [Result] The best indicative bacterium was Al-ternaria solani, the optimum process parameters in shaking flask on fermentation consisted of initial pH of 8.0, culture at 30 ℃, loadage 90 ml/250 ml, rotation 180 r/min, and fermentation time of 48 h. The results also indicated that glucose was the best carbon source for the antibiotics productivity of BL-21, and beef extract was the best nitrogen source. In addition, univalent ion Cl＋ and divalent ion Mn2＋ stimu-lated BL-21 antibacterial active component biosynthesis. [Conclusion] Optimized medi-um is more conducive to produce antimicrobial substances.
基金Supported by Doctoral Initial Fund of Ludong University (No.43304)
文摘Amphioxus, a cephalochordate, is an important model fish for studies in evolution and comparative biology. A successful cell culture from amphioxus tissues in vitro would help understanding some basic issues. To determine the optimal culture conditions for proliferation of amphioxus cells, primary cultures were initiated from buccal cirri, tail, gill, gut and metapleural fold of amphioxus Branchiostoma belcheri tsingtauense. The media tested were L-15, F-12, M 199, MEM, DMEM, PRMI 1640 and LDF, each was supplemented with 20% fetal bovine serum. The optimal conditions include tail tissue cultured in L-15 or F-12 with supplement of 20% FBS and 1.5% NaCl at about 25℃.
基金The National Natural Science Foundation of China under contract No.41176135
文摘Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy （SEM） and sequence comparisons of two segments of genes （small ribosomal subunit and large subunit of Rubisco）, the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm （OD680） under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates （RGR） peaked at the highest tested level （0.25 mmol/L）. The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.
文摘The focus of this research lies in community empowerment based on culture and local communities as well as sustainable ecotourism,which is directed at a complicated mechanism of empowerment elements,local culture that is thick in ecotourism to get added value for the novelty of ecotourism research.The object of research is Wasur National Park(WNP),Papua,Indonesia.Qualitative methods have been used to obtain accurate data and information,i.e.,in-depth interviews with indigenous people to find out the benefits or functions of their culture that can be developed in ecotourism,interviews with leaders and staff of WNP and the Department of Culture and Tourism to find out the potential and processes empowerment and existing tourism potential.As a result,from the perspective of empowerment,local people will easily follow the empowerment process provided that they use methods that are culturally appropriate which is from the viewpoints from the culture of sasi,totem and sacred places.The culture adopted by the community is in accordance with the principles of ecotourism that supports sustainability,environmental conservation,protection of environmental resources and increases economic value.However,it is recommended to carry out modified socialization in accordance with the current conditions.Hence,tourists who visit WNP do not become afraid of the very rigid sanctions which are applied to them who violate the existing cultural and environmental customs.Moreover,to get added economic value in the tourism business within WNP,it is necessary to explore the potential of cultural wealth,natural and biological wealth so that it becomes the main attraction in carrying out the economic empowerment of local communities in the field of ecotourism.
文摘Objective: To explore the mechanism of neurotropism in peripheral nerve regeneration by assessing the bioactivity of regeneration microcircumstance on motoneurons. Methods The motor branch Of femoral nerve to quadriceps was incised and the distal stump was sutured with one-end silicone chamber. The nerve regeneration chamber fluids from distal motor nerve stumps (motor branch of femoral nerve ) (MD-NRCF) was collected 7d post-operatively, and with the same method, nerve regeneration conditioned fluids from distal stumps nerve stumps (saphenous nerve ) (SD-NRCF) was collected. The dissociated rat’s motoneurons were co-cultured with MD-NRCF, SD-NRCF, basic fibroblast growth factor (b-FGF) and serum-free medium for 72h respectively and then were photographed under phase-contrast microscope. The longest neurites and cellbody areas of motoneurons from each group were measured by cell image processing computer system. MTT colorimetric assay was also used to measure cell activation. Results The cells of MD-NRCF group had significantly longer neurites than the other 3 groups, and their activation was also superior to those of the other groups. Conclusion These results indicate that MD-NRCF has more significant neurite-promoting and neurobiological effects on motoneuron than SD-NRCF and b-FGF.
