Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suc...Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.展开更多
Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of s...Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of sodium tripolyphosphate (STPP). The optimum temperature and pH for the TPPase of myosin subfragment-1 were 30℃ and pH 5.0, and at pH 8.0 the TPPase also showed a high activity. Mg2+ was necessary to TPPase. The TPPase activity of myosin subfragment-1 was activated by Mg2+ under low concentrations, but was inhibited when the concentration was over 17 mmolL-1. The TPPase activity was also affected by KCl. The optimum concentration of KCl for TPPase was 0.3 molL-1 under the condition of 17 mmolL-1 Mg2+. The TPPase activity was significantly inhibited by EDTA-Na2. Reagents such as KBr, KI and KIO3 could inhibit the TPPase effectively. K2Cr2O7 as well as KMnO7 and KNO3 exhibited weak inhibiting effects. The TPPase converted STPP to pyrophosphate (PP) and orthophosphate (Pi) stoichiometrically with a KM of 3.2 mmolL-1.展开更多
[Objective] To investigate the effects of amino acid powder,fermented rapeseed meal and fermented cottonseed meal on the growth performance,amino acid absorption,body composition and liver function of allogynogentic c...[Objective] To investigate the effects of amino acid powder,fermented rapeseed meal and fermented cottonseed meal on the growth performance,amino acid absorption,body composition and liver function of allogynogentic crucian carp.[Method] The allogynogentic crucian carps with the average initial weight of 17.3 g were divided into control group and six experimental groups randomly.The allogynogentic crucian carps in the control group and experimental groups were fed a basal diet and the basal diets supplemented by amino acid powder,fermented rapeseed meal and fermented cottonseed meal,respectively.The growth rate and specific growth rate of allogynogentic crucian carps,the content of amino acids in serum and feeds,the composition indicators of body,muscle and liver,as well as the activities of glutamic-pyruvic transaminase(GPT) and glutamic-oxaloacetic transaminase(GOT) in liver and serum were determined,respectively.[Result] The growth rate and specific growth rate(SGR) of allogynogentic crucian carps in the 3% amino acid powder group and the 6% fermented cottonseed meal group were increased greatly(P < 0.05),and no significant difference was found between experimental group and control group.The serum lysine content of the 3% amino acid powder group and the 6% fermented cottonseed meal group was higher than that of the control group.In the experimental groups,the absorption of four essential amino acids was up to a peak at 4 h after feeding,which was consistent with the control group.The body composition and liver function of allogynogentic crucian carps had no significant difference between the experimental groups and the control group.[Conclusion] The 3% amino acid powder,6% fermented cottonseed meal and 6% fermented rapeseed meal can substitute fish meal,cottonseed meal and rapeseed meal to improve the growth performance,amino acid absorption of the allogynogentic crucian carps.展开更多
Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of t...Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.展开更多
The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquat...The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment.The results showed that the development of bighead and silver carp embryos was delayed,the mortality and abnormality rates were raised when the embryos were treated with≥0.010 mg.L-1 nitrobenzene,and with≥0.085 mg.L-1 nitrobenzene,the mortality rates showed 100%.展开更多
The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor...The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.展开更多
The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-prod...The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (</span><span style="font-family:Verdana;"><i>Cyprinus carpio</i></span><span style="font-family:Verdana;"> L.), and identified belonging to the genera of </span><i><span style="font-family:Verdana;">Enterobacter</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">·</span></span><span></span><span></span><span style="font-family:""><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL</span></span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">h</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">g</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><sub><span style="font-family:Verdana;">sugar</span></sub><span style="font-family:Verdana;">, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.展开更多
文摘Study of the feeding capacity of silver carp and bighead carp by means of experimental ecologyshowed that the filtering frequency of silver carp was slightly greater than that of bighead carp,but thatthe latter’s suction volume was much greater than the former’s so the filtering rate(filtering frequency mul-tiplied by the suction volume)of silver carp was smaller than that of bighead carp.The filtering efficien-cy of silver carp for phytoplankton was greater than that of bighead carp for them.The removal ratesof silver carp for phytoplankton were greater than those of bighead carp,but for zooplankton the formerwere smaller than the latter.For food particles about 70 μm both removal rates were almost equal.The feeding habits of the two species in natural waters is also discussed in the paper.
基金This work was supported by the National Natural Science Foundation of China （No. 30671632）supported by the National High-tech Research and Development Project of China （No. 2006AA09Z444）.
文摘Myosin subfragment-1 was prepared from the myofibrils of bighead carp (Aristichthys nobilis). The myosin subfrag- ment-1 was proved to have the activity of tripolyphosphatase (TPPase) responding to the hydrolysis of sodium tripolyphosphate (STPP). The optimum temperature and pH for the TPPase of myosin subfragment-1 were 30℃ and pH 5.0, and at pH 8.0 the TPPase also showed a high activity. Mg2+ was necessary to TPPase. The TPPase activity of myosin subfragment-1 was activated by Mg2+ under low concentrations, but was inhibited when the concentration was over 17 mmolL-1. The TPPase activity was also affected by KCl. The optimum concentration of KCl for TPPase was 0.3 molL-1 under the condition of 17 mmolL-1 Mg2+. The TPPase activity was significantly inhibited by EDTA-Na2. Reagents such as KBr, KI and KIO3 could inhibit the TPPase effectively. K2Cr2O7 as well as KMnO7 and KNO3 exhibited weak inhibiting effects. The TPPase converted STPP to pyrophosphate (PP) and orthophosphate (Pi) stoichiometrically with a KM of 3.2 mmolL-1.
基金supported by the Applied Basic Research Projects of Suzhou City (YJG0912)
文摘[Objective] To investigate the effects of amino acid powder,fermented rapeseed meal and fermented cottonseed meal on the growth performance,amino acid absorption,body composition and liver function of allogynogentic crucian carp.[Method] The allogynogentic crucian carps with the average initial weight of 17.3 g were divided into control group and six experimental groups randomly.The allogynogentic crucian carps in the control group and experimental groups were fed a basal diet and the basal diets supplemented by amino acid powder,fermented rapeseed meal and fermented cottonseed meal,respectively.The growth rate and specific growth rate of allogynogentic crucian carps,the content of amino acids in serum and feeds,the composition indicators of body,muscle and liver,as well as the activities of glutamic-pyruvic transaminase(GPT) and glutamic-oxaloacetic transaminase(GOT) in liver and serum were determined,respectively.[Result] The growth rate and specific growth rate(SGR) of allogynogentic crucian carps in the 3% amino acid powder group and the 6% fermented cottonseed meal group were increased greatly(P < 0.05),and no significant difference was found between experimental group and control group.The serum lysine content of the 3% amino acid powder group and the 6% fermented cottonseed meal group was higher than that of the control group.In the experimental groups,the absorption of four essential amino acids was up to a peak at 4 h after feeding,which was consistent with the control group.The body composition and liver function of allogynogentic crucian carps had no significant difference between the experimental groups and the control group.[Conclusion] The 3% amino acid powder,6% fermented cottonseed meal and 6% fermented rapeseed meal can substitute fish meal,cottonseed meal and rapeseed meal to improve the growth performance,amino acid absorption of the allogynogentic crucian carps.
基金the Guangxi Science and Technology Major Project(No.AA17204095-8)the Open Fund of Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture(No.GXKEYLA2019-05)the China-ASEAN Maritime Cooperation Fund(No.CAMC-2018F)。
文摘Although intestinal fungi play important roles in host health and disease,the composition and diversity of fungal communities remain poorly reported in fish.In this study,fungi in the fore-,mid-,and hindintestine of tilapia(Oreochromis mossambicus)and bighead carp(Aristichthys nobilis)from Hongchaojiang Reservoir in Guangxi,China were investigated by ITS sequencing.Based on this,we obtained 1763478 high-quality tags,which clustered into 1089 operational taxonomic units(OTUs).In total,404 OTUs were annotated,of which 310,68,and 26 belonged to Ascomycota,Basidiomycota,and other,respectively.Results show significant differences in the community composition of intestinal fungi between tilapia and bighead carp but not within their different intestinal segments.Furthermore,154 of the 404 annotated OTUs were considered reliable and were classified into three trophic modes and nine guilds.The three trophic modes consisted of 108 OTUs of saprotrophic fungi,41 OTUs of pathotrophic fungi,and five OTUs of symbiotrophic fungi.The top three most abundant OTUs overall(i.e.,Otu000002,Scopulariopsis acremonium;Otu000018,Alternaria palandui;Otu000034,Aureobasidium pullulans)showed lower abundance in the hind-intestinal segments of bighead carp,suggesting uneven distribution of these fungi in this species.In addition,saprotrophic and pathotrophic fungi were markedly decreased in the hindintestine.It is indicated that the fungal community was not only related to host species specificity but also to the respective physiological functions of different intestinal segments.These findings provide valuable information on the composition,structure,and potential function of the intestinal fungi community associated with different intestinal segments in tilapia and bighead carp under natural conditions,thus highlighting the importance of fungi as an integral part of the inte stinal microbiota in maintaining host health.
文摘The effect of various concentrations of nitrobenzene on the mortality and abnormality rate of bighead and silver carp embryos were studied to provide reference for the evaluation of the effect of nitrobenzene to aquatic organisms and aquatic environment.The results showed that the development of bighead and silver carp embryos was delayed,the mortality and abnormality rates were raised when the embryos were treated with≥0.010 mg.L-1 nitrobenzene,and with≥0.085 mg.L-1 nitrobenzene,the mortality rates showed 100%.
文摘The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.
文摘The biological hydrogen generating from fermentation of low-cost lignocellulosic feedstocks by hydrogen-producing bacteria has attracted many attentions in recent years. In the present investigation, ten hydrogen-producing bacteria were newly isolated from the intestine of wild common carp (</span><span style="font-family:Verdana;"><i>Cyprinus carpio</i></span><span style="font-family:Verdana;"> L.), and identified belonging to the genera of </span><i><span style="font-family:Verdana;">Enterobacter</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span style="font-family:Verdana;"> based on analysis of the 16S rDNA gene sequence and examination of the physiological and biochemical characteristics. All the isolates inherently owned the ability to metabolize xylose especially the cotton stalk hydrolysate for hydrogen production with hydrogen yield (HY) higher than 100 mL</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;">·</span></span><span></span><span></span><span style="font-family:""><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-1</span></sup><span style="font-family:Verdana;">. In particular, two isolates, WL1306 and WL1305 obtained higher HY, hydrogen production rate (HPR), and hydrogen production potential (HPP) using cotton stalk hydrolysate as sugar substrate than the mixed sugar of glucose & xylose, which obtained the HY of 249.5 ± 29.0, 397.0 ± 36.7 mL</span></span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPR of 10.4 ± 1.2, 16.5 ± 1.5 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">h</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">, HPP of 19.5 ± 2.3, 31.0 ± 2.8 mL</span><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">L</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><span style="font-family:Verdana;">·</span><span style="font-family:Verdana;">g</span><sup><span style="font-family:Verdana;">-</span></sup><sup><span style="font-family:Verdana;">1</span></sup><sub><span style="font-family:Verdana;">sugar</span></sub><span style="font-family:Verdana;">, separately. The generation of soluble metabolites, such as the lactate, formate, acetate, succinate and ethanol reflected the mixed acid fermentation properties of the hydrogen production pathway.
