Radix aucklandiae from Yunnan Province in China is a significant medicinal plant. In the present study, the essential oil composition from?Radix aucklandiae roots was investigated by gas chromatography-mass spectromet...Radix aucklandiae from Yunnan Province in China is a significant medicinal plant. In the present study, the essential oil composition from?Radix aucklandiae roots was investigated by gas chromatography-mass spectrometry (GC-MS). A total of 23 compounds representing 57.95% of the essential oil were tentatively identified. The main constituents were eremanthin (12.74%), d-Guaiene (6.26%), ζ-Himachalene (6.16%) and l-Caryophyllene (4.84%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oil from R. aucklandiae were evaluated against three Gram-positive bacteria (Staphylococcus aureus, Staphylococcus albus and Bacillus subtilis) three Gram-negative bacteria (Salmonella typhimurium, Escherichia coli and Shigella dysenteriae). Results revealed that the essential oil exhibited significant in vitro antimicrobial property. Among all the tested microorganisms, the essential oil showed the strongest inhibitory effect against S. typhimurium. The data of this study suggests that the essential oil from Radix aucklandiae has great potential for application as a natural antimicrobial agent to preserve food.展开更多
Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. In order to research the relieve effect of Bacillus subtilis QM3 on wheat roots (Triticum aestivum L.), af...Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. In order to research the relieve effect of Bacillus subtilis QM3 on wheat roots (Triticum aestivum L.), after wheat seeds germination for two days, wheat root caused, the experimental materials were divided into four large groups and each large group was placed in 6 petri dishes as six small groups, and then four large groups respectively cultivated with sterile water (CK), 108 CFU/ml B. subtilis QM3 (B1), 107 CFU/ml B. subtilis QM3 (B2) and 106 CFU/ml B. subtilis QM3 (B3) for 2 days, after that stressed with lead nitrate, Pb (NO)2, Pb2+ concentration calculation at five concentrations (50, 250, 500, 1000, 2000 mg/L), sterile water and different Pb2+ concentration liquid respectively cultivated the 6 small groups in each large group measuring root morpholog and assaying changes of antioxidant enzyme activity. The results showed that: with the increase of the Pb2+ concentration, root morphology index and the activity of antioxidant enzyme increased first and then decreased. Root morphology index reached the maximum in 50 mg/L Pb2+ concentration. B. subtilis QM3 clearly promoted the growth of the root and the antioxidant enzyme activity (p 0.05). Without Pb stress, B. subtilis QM3 had the best improving effect on root morphology. When Pb2+ concentration was 50 mg/L, superoxide dismutase (SOD) and ascorbate peroxidase (APX) reached the maximum. SOD activity, compared with CK, B1, B2 and B3 respectively, increased by 8.05%, 27.41% and 9.79%. APX activity, compared with CK, B1, B2 and B3 respectively, increased by 52.70%, 111.15% and 14.16%. Catalase (CAT) and peroxidase (POD) reached the maximum at the Pb2+ concentration was 500 mg/L. CAT activity, compared with CK, B1, B2 and B3 respectively, increased by 59.93%, 83.46% and 70.59%. POD activity, compared with CK, B1, B2 and B3 respectively, increased by 2.88%, 10.11% and 7.67%. Result suggested that B. subtilis QM3 could improve root growth and antioxidant enzyme activity of the wheat root under lead stress.展开更多
1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described her...1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L<sup>-1</sup>, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L<sup>-1</sup> and a molar yield (mol<sub>1,3-PD</sub> mol<sub>Glycerol</sub>-1</sup> of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.展开更多
文摘Radix aucklandiae from Yunnan Province in China is a significant medicinal plant. In the present study, the essential oil composition from?Radix aucklandiae roots was investigated by gas chromatography-mass spectrometry (GC-MS). A total of 23 compounds representing 57.95% of the essential oil were tentatively identified. The main constituents were eremanthin (12.74%), d-Guaiene (6.26%), ζ-Himachalene (6.16%) and l-Caryophyllene (4.84%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the essential oil from R. aucklandiae were evaluated against three Gram-positive bacteria (Staphylococcus aureus, Staphylococcus albus and Bacillus subtilis) three Gram-negative bacteria (Salmonella typhimurium, Escherichia coli and Shigella dysenteriae). Results revealed that the essential oil exhibited significant in vitro antimicrobial property. Among all the tested microorganisms, the essential oil showed the strongest inhibitory effect against S. typhimurium. The data of this study suggests that the essential oil from Radix aucklandiae has great potential for application as a natural antimicrobial agent to preserve food.
文摘Lead (Pb) is an environmental pollutant extremely toxic to plants and other living organisms including humans. In order to research the relieve effect of Bacillus subtilis QM3 on wheat roots (Triticum aestivum L.), after wheat seeds germination for two days, wheat root caused, the experimental materials were divided into four large groups and each large group was placed in 6 petri dishes as six small groups, and then four large groups respectively cultivated with sterile water (CK), 108 CFU/ml B. subtilis QM3 (B1), 107 CFU/ml B. subtilis QM3 (B2) and 106 CFU/ml B. subtilis QM3 (B3) for 2 days, after that stressed with lead nitrate, Pb (NO)2, Pb2+ concentration calculation at five concentrations (50, 250, 500, 1000, 2000 mg/L), sterile water and different Pb2+ concentration liquid respectively cultivated the 6 small groups in each large group measuring root morpholog and assaying changes of antioxidant enzyme activity. The results showed that: with the increase of the Pb2+ concentration, root morphology index and the activity of antioxidant enzyme increased first and then decreased. Root morphology index reached the maximum in 50 mg/L Pb2+ concentration. B. subtilis QM3 clearly promoted the growth of the root and the antioxidant enzyme activity (p 0.05). Without Pb stress, B. subtilis QM3 had the best improving effect on root morphology. When Pb2+ concentration was 50 mg/L, superoxide dismutase (SOD) and ascorbate peroxidase (APX) reached the maximum. SOD activity, compared with CK, B1, B2 and B3 respectively, increased by 8.05%, 27.41% and 9.79%. APX activity, compared with CK, B1, B2 and B3 respectively, increased by 52.70%, 111.15% and 14.16%. Catalase (CAT) and peroxidase (POD) reached the maximum at the Pb2+ concentration was 500 mg/L. CAT activity, compared with CK, B1, B2 and B3 respectively, increased by 59.93%, 83.46% and 70.59%. POD activity, compared with CK, B1, B2 and B3 respectively, increased by 2.88%, 10.11% and 7.67%. Result suggested that B. subtilis QM3 could improve root growth and antioxidant enzyme activity of the wheat root under lead stress.
文摘1,3-Propanediol is a promising renewable resource produced by microbial production. It is mainly used in many synthetic reactions, particularly applied to the polymer synthesis and cosmetics industry. We described here the isolation of strain ZH-1, which has the ability of high production with 1,3-propanediol, from Fenhe River in China. It was classified as a member of K. pneumoniae after the study of phenotypic, physio-logical, biochemical and phylogenetic (16S rDNA). The initial glycerol concentration, fermentation time and pH value of strain ZH-1 were determined to be 50 g·L<sup>-1</sup>, 36 h and 8.0. Under these conditions, the practical yield of 1,3-PD was 18.53 g·L<sup>-1</sup> and a molar yield (mol<sub>1,3-PD</sub> mol<sub>Glycerol</sub>-1</sup> of 1,3-propanediol to glycerol of 0.497. In addition, we found that for the strain ZH-1, the optimum grown pH was 9.0, so we can deter-mine that it is a new member of alkali-resistant strains.
