[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were...[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were cultured under heavy metal stress including Cu2＋,Hg2＋,Pb2＋,Cd2＋ and Cr6＋ in different concentrations. Then the growth curves of the bacteria were determined to investigate the effects of exogenous heavy metals on the growth of the two kinds of bacteria. [Result] The proliferation of the two bacteria was inhibited at high concentrations of Hg2＋ and Cd2＋ respectively,and G＋ is more sensitive to them than G-; when the heavy metal concentration was 50 mg/L,the toxicity of the five kinds of heavy metals on the two bacteria was Hg2＋Cd2＋Cu2＋Cr6＋≈Pb2＋. [Conclusion] The research will provide a basis to explore the effects of heavy metal on environment and ecological system.展开更多
Application of high-speed centrifugation and high-performance liquid chro- matography to separation and purification obtained a new type of natural antibacteri- al substance from Escherichia co/i cell. Against Staphy/...Application of high-speed centrifugation and high-performance liquid chro- matography to separation and purification obtained a new type of natural antibacteri- al substance from Escherichia co/i cell. Against Staphy/ococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus, Pseudomonas, solanacearum the minimal inhibitory concentration （MIC） was 2.5, 5, 0.625 iJg/ml, 0.625 and 1.25 g/ml, the minimum bactericidal concentration （MBC） was 5, 5, 1.25, 2.5, 2.5 g/ml, respectively. Composition identification of chemical method and mass spectrometry shows that the antibacterial active substance alkaloids; and the safety evaluation on the model plant Arabidopsis shows that the antibacterial active substance had no inhibitory and adverse effects on the growth and development of plants. The experimental results show that the antibacterial active substance is a broad-spectrum, high efficiency, safe antibacterial natural product, with the prospect of development and utilization of alternative antibiotics.展开更多
In this study,the intestinal microbiota of kuruma shrimp(Marsupenaeus japonicus) was examined by molecular analysis of the 16S rDNA to identify the dominant intestinal bacteria and to investigate the effects of Bacill...In this study,the intestinal microbiota of kuruma shrimp(Marsupenaeus japonicus) was examined by molecular analysis of the 16S rDNA to identify the dominant intestinal bacteria and to investigate the effects of Bacillus spp.on intestinal microbial diversity.Samples of the intestines of kuruma shrimp fed normal feed and Bacillus spp.amended feed.PCR and denaturing gradient gel electrophoresis(DGGE) analyses were then performed on DNA extracted directly from the guts.Population fingerprints of the predominant organisms were generated by DGGE analysis of the universal V3 16S rDNA amplicons,and distinct bands in the gels were sequenced.The results suggested that the gut of kuruma shrimp was dominated by Vibrio sp.and uncultured gamma proteobacterium.Overall,the results of this study suggest that PCR-DGGE is a possible method of studying the intestinal microbial diversity of shrimp.展开更多
基金Supported by Science Research Fund Project of Yunnan Provincial Education Department "Physiological Toxicity of Heavy Metal Stress on Several Microorganisms" (09Y0382)Yunnan Natural Science Foundation Project "Toxicity Mechanism of Three Aquatic Plants under Heavy Metal Pollution" (2008ZC161M)~~
文摘[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili. [Method] Using traditional culture method,Escherichia coli and Bacillus subtili were cultured under heavy metal stress including Cu2＋,Hg2＋,Pb2＋,Cd2＋ and Cr6＋ in different concentrations. Then the growth curves of the bacteria were determined to investigate the effects of exogenous heavy metals on the growth of the two kinds of bacteria. [Result] The proliferation of the two bacteria was inhibited at high concentrations of Hg2＋ and Cd2＋ respectively,and G＋ is more sensitive to them than G-; when the heavy metal concentration was 50 mg/L,the toxicity of the five kinds of heavy metals on the two bacteria was Hg2＋Cd2＋Cu2＋Cr6＋≈Pb2＋. [Conclusion] The research will provide a basis to explore the effects of heavy metal on environment and ecological system.
基金Supported by Guangdong Scientific and Technological Bureau(2012B020401012)~~
文摘Application of high-speed centrifugation and high-performance liquid chro- matography to separation and purification obtained a new type of natural antibacteri- al substance from Escherichia co/i cell. Against Staphy/ococcus aureus, Escherichia coli, Pasteurella multocida, Streptococcus, Pseudomonas, solanacearum the minimal inhibitory concentration （MIC） was 2.5, 5, 0.625 iJg/ml, 0.625 and 1.25 g/ml, the minimum bactericidal concentration （MBC） was 5, 5, 1.25, 2.5, 2.5 g/ml, respectively. Composition identification of chemical method and mass spectrometry shows that the antibacterial active substance alkaloids; and the safety evaluation on the model plant Arabidopsis shows that the antibacterial active substance had no inhibitory and adverse effects on the growth and development of plants. The experimental results show that the antibacterial active substance is a broad-spectrum, high efficiency, safe antibacterial natural product, with the prospect of development and utilization of alternative antibiotics.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(Nos.2006AA100311,2008AA100805)
文摘In this study,the intestinal microbiota of kuruma shrimp(Marsupenaeus japonicus) was examined by molecular analysis of the 16S rDNA to identify the dominant intestinal bacteria and to investigate the effects of Bacillus spp.on intestinal microbial diversity.Samples of the intestines of kuruma shrimp fed normal feed and Bacillus spp.amended feed.PCR and denaturing gradient gel electrophoresis(DGGE) analyses were then performed on DNA extracted directly from the guts.Population fingerprints of the predominant organisms were generated by DGGE analysis of the universal V3 16S rDNA amplicons,and distinct bands in the gels were sequenced.The results suggested that the gut of kuruma shrimp was dominated by Vibrio sp.and uncultured gamma proteobacterium.Overall,the results of this study suggest that PCR-DGGE is a possible method of studying the intestinal microbial diversity of shrimp.
