Abstract:

Abstract:[Objective] We used ribosme engineering technology, with which antibiotic-resistant strains are resulted from mutations on microbial ribosme, to improve the capacity to produce ε-PL by Streptomyces albulus AS3-14. [Methods] A single drug-resistant mutant was obtained from the original S. albulus AS3-14 with the presence of mutagen of streptomycin. A double drug-resistant mutant S. albulus WG-608 was obtained on the basis of single drug-resistant mutant with the presence of mutagen of rifampicin, of which the ε-PL productivity was improved. [Results] The highest ε-PL-producing strain, named S. albulus WG-608, could produce ε-PL of 3.7 g/L in shake-flask and 53.0 g/L in a 5-L fermentor, 42.3% and 32.5%, respectively higher than that of the parent strain. [Conclusion] Screening of streptomycin and rifampicin resistant strains might be a promising alternative to obtain a high ε-PL-producing S. albulus strain.

Abstract:

Abstract:[Objective] Ramie degumming bacterial consortium RAMCD407 was used to analyze the bacterial function and reveal the mechanism of interactions among different strains. [Methods] Several bacteria were cultured and isolated from RAMCD407 from four media, and these bacteria were then identified by 16S rRNA gene sequencing. Pectinase activity, xylanase activity and gum removal ratio of the isolated microbes were measured. Composite strains JHY were constructed by combination of the isolated strains, and the influences of different strains on the performance of JHY were analyzed. [Results] Twenty-five isolated strains were identified as genus Bacillus, Pseudomonas, Enterobacter, Rummeliibacillus, Sphingobacterium, and Exiguobacterium. Among them, strain 2H2 played an important role, and it could improve the pectinase activity, xylanase activity and gum removal ratio of JHY; However, strain JY31 could reduce the enzyme activity and gum removal ratio of JHY by inhibiting the growth of other strains. [Conclusion] 2H2 was the important strain in JHY, and elimination of JY31 could improve the gum removal efficiency of JHY.

Abstract:[Objective] To explain the reason of the improvement of ε-poly-L-lysine (ε-PL) in Streptomyces by genome shuffling (GS) through the analysis of ε-PL metabolic flux distribution between the parent strains and the high yield strain. [Methods] Glucose tolerant Streptomyces sp. AS32 and ε-PL tolerant Streptomyces albulus F15 were selected as parent strains for GS. Three rounds of GS were carried out and a higher ε-PL producing shuffled strain Streptomyces sp. AF3-44 was obtained. The ε-PL synthetic network was constructed by metabolic flux analysis method and the metabolic fluxes among the above strains were compared. [Results] Shuffled strain, AF3-44, had a flask yield of 3.1 g/L which was increased by 34% and 29% compared with those of parent strains AS32 and F15 respectively. The fluxes to the tricarboxylic acid cycle (TCA) were highest in AS32, whereas and the fluxes to the pentose phosphate pathway (PPP) are highest in F15. AF3-44 had highest fluxes from oxaloacetic acid to aspartic acid and ε-PL synthesis, while it had moderate TCA and PPP fluxes, where the flux to isocitrate in TCA was 77% and 116% of those in AS32 and F15 respectively, and the flux to ribulose-5-phosphate was 149% and 92% of those in AS32 and F15 respectively. [Conclusion] Genome shuffling led to increase of flux to the precursor lysine and ε-PL, and the redistribution of metabolic fluxes in PPP and TCA which contributed to the improvement of ε-PL in the shuffled strain.

Abstract:[Objective] The goal of this study is to reveal the dynamics of bacterial communities and their relationship with environmental variables through analysis of 16S rRNA gene clone libraries derived from the three stations of Xinkai River estuary for better understanding the ecological functions of this region. [Methods] In August 2014, water samples were collected from 3 stations of Xinkai River estuary (XKH) area and its adjacent water in the coast of Qinhuangdao. Bacterial abundance was estimated using a fluorescence microscope and 16S rRNA gene clone libraries derived from the total bacterial DNA of the water samples. [Results] Total number of bacteria (2.62×106 cells/mL) and diversity of station W1 were higher than that of Xinkai River estuary XKH station (6.62×105 cells/mL) and the station W2 (2.02×106 cells/mL); 16S rRNA gene clone libraries of the stations XKH, W1, and W2 yielded 46, 51 and 56 OTUs, respectively. Those OTUs belonged to the members of 7 different bacterial phyla: Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Planctomycetes and Verrucomicrobia. Proteobacteria was the predominant taxa in the clone libraries of the stations XKH (50.9%) and W2 (75.9%). On the other hand, members of Cyanobacteria were the predominant taxa (38.2%) in the station W1. These dominant groups were closely related to availability of nitrogen and other nutrients of water column. The environmental factors, which affected the distribution of bacterial communities, were dissolved oxygen, pH and nitrogen nutrients. [Conclusion] Xinkai River estuary and its adjacent seawater contained rich bacterial diversity. Particularly, the water samples from the transition zone between the estuary and the sea harbored much higher bacterial diversity. Distribution of bacterial communities was largely regulated by nitrogen nutrients.

Abstract:[Objective] We evaluated statistical methods of multivariate variance, multiple linear regression and path analysis and used multivariate statistical methods to analyze the microbial content in soil. [Methods] Through researching principle, application conditions and application to solve the problem of these three common statistical methods, we used different methods to analyze the impact of various factors on the microbial content in soil, and used SPSS software to solve. [Results] We found that there were differences in the amount of microbial content in the soil under different rainfall. Ammonium nitrogen content and altitude with proteobacteria content showed linear relationship. In soil, proteobacteria content increased with the increase of ammonium nitrogen content, and the direct effect of ammonium nitrogen content on proteobacteria content was most important. Ammonium nitrogen content, total nitrogen, altitude with actinobacteria content in soil showed adverse linear relationship, and the negative effect of total nitrogen content on actinobacteria content in soil was the most, but the direct effect of ammonium nitrogen content on actinobacteria content was the most. Compared with descriptive statistics and multivariate variance analysis showed that using descriptive statistical methods only draw rainfall was one of the factors of the relative content of different bacterial communities in soil and didn’t know the impact of rainfall on the changes of content of microorganisms and what the cause of the significant difference between the 6 gradients of rainfall. Variance analysis methods could solve the above problems. Compared with multiple linear regression analysis and path analysis showed that correlation coefficient obtained by multiple linear regression analysis only said ammonium nitrogen content, total nitrogen content and altitude and deformation of bacterial phyla content (actinobacteria content) the relationship between the close degree, but unable to explain and analyze the composition and source of the relationship, path analysis methods could solve this problem. [Conclusion] Path analysis method in the analysis of relevant problems was superior to multiple linear regression analysis method. Path analysis more than multiple linear regression analysis methods could reflect the direct and indirect impact of factors on the proteobacteria content (actinobacteria content). Its analysis conclusion was more intuitive, able to explain the problem.

Abstract:[Objective] Screen and isolate Haloalkalophilic microorganisms from the black lake of Yuli County in Xinjiang and take the species identification analysis. [Methods] Traditional isolation and identification techniques were used to study the morphological, physiological and biochemical characteristics and sequence analysis based on 16S rRNA gene were proceeded. [Results] 25 strains of culturable Haloalkalophilic bacteria were separated and identified from the sample. The physiological and biochemical characteristics, 16S rRNA gene sequence analysis and phylogenetic analysis showed that these microorganisms distributed in five genera which were Halorubrum, Haloarcula, Natrialba, Halohasta and Halopiger etc. Among them, the most dominant bacteria group is Halorubrum, next is Natrialba. Sequence homology of 16S rRNA gene were 95.75% respectively, herald some potential new species (Identification of new species not shown here), the Growth condition experiment of 25 strains of culturable Haloalkalophilic bacteria show that concentration range of NaCl was 15%?30%, with optimum concentration was 20%?25%, the pH range for growth was 7.0?13.0, optimum at 9.0?10.0. The results of physical and biochemical characteristics show that among 25 strains of culturable Haloalkalophilic bacteria, 5 strains belong to amylase producing bacteria, accounted for 20%, 4 strains belong to protease producing bacteria, accounted for 16%, 15 strains belong to esterase Twain hydrolysis 20 producing bacteria, accounted for 60%, 7 strains belong to Twain hydrolysis 40 producing bacteria, accounted for 28%, 4 straise belong to Twain hydrolysis 80 producing bacteria, accounted for 16%. 14 strains belong to hydrogen peroxide producing bacteria, accounted for 56%. 9 strains of these bacteria can produce 4 kinds of enzymes, 2 strains can produce 3 kinds of enzymes at the same time, showed the diversity of enzyme production of the alkaline bacteria. 19 strains of the bacteria were positive for nitrate reduction. [Conclusion] The study shows the physiological and biochemical characters diversity and phylogenetic diversity of Haloalkalophilic bacteria in the black lake of Yuli County in Xinjiang, and there are much more abundant new microbial groups in the lake. The study has the regional characteristics and potential application value, recommend that the microbia urgent need systematic research and further develope and utilize.

Abstract:[Objective] In order to study soil bacterial community diversity and space-time analysis, we chose Usu mud volcano in Xinjiang province as the research object. [Methods] we selected four different soil habitats to take samples in April, July, November, 2014. The Illumina MiSeq sequencing with 16S rRNA V3-V4 variable region was adopted to analyze the bacterial community structures of Usu mud volcano in Xinjiang province. [Results] a total number of 29 005 operational taxonomic units (OTUs) were obtained from mud volcano soil under the similarity level of 97%. For phyla level, we have got 38 groups of bacterial that the Proteobacteria, Actinobacteria and Bacteroidetes were the dominant groups. For genus level, we have got 72 groups, but the most abundant genera were unclassified. Diversity index showed that the type D has a higher abundance effect and diversity index. Compared with the bacteria community diversity and physicochemical property, we found that bacteria diversity was decreased with the increasing of soil fertility, which shows negative correlations between bacteria diversity and physicochemical property. The results of PCA and heat map indicated that the community composition of type A has no significant variation with space-time dynamic changes, but type C is opposite. [Conclusion] Compared with traditional method, Illumina MiSeq sequencing can provide a more comprehensive understanding of microbial diversity in the environmental samples and these results reveal clues that it is possible to contain abundant microbial resources, and it lays the foundation of studying ecosystem of mud volcano and provides guidance for exploitation and utilization of microbial resources more reasonably in Usu mud volcano.

Abstract:[Objective] This study aimed to construct a co-expression system of hexokinase and glucose-6-phosphate dehydrogenase in Escherichia coli to regenerate NADPH with glucose as substrate efficiently. [Methods] Hexokinase genes hkgs and hkpp were cloned and expressed in E. coli BL21(DE3), and then the co-expression system of hexokinase and glucose-6-phosphate dehydrogenase was established to achieve efficient in-situ regeneration of NADPH. Among the two co-expression systems, BL21(HKgs+GpdPP) was better, so the expression condition of BL21(HKgs+GpdPP) was optimized. [Results] The catalytic activity of NADPH regeneration reached 856 U/L. The coupling catalysis was performed with this co-enzyme regeneration system and alcohol dehydrogenase AdhR, the catalytic activity of asymmetric reduction of ethyl 4-chloro-3-oxobutanoate was enhanced up to 2.5 times. [Conclusion] Through co-expression system of hexokinase and glucose-6-phosphate dehydrogenase in Escherichia coli, new effective NADPH regeneration system was constructed, and success for a symmetric reduction by alcohol dehydrogenase.

Abstract:[Objective] To explore the role of SRO9 in the endoplasmic reticulum stress (ERS) in saccharomyces cerevisiae. [Methods] The SRO9-deletion yeast strain was made by PCR-mediated homologous recombination in wild-type yeast. Colony-forming ability of SRO9-deletion and wild-type strains was analyzed under the tunicamycin-treated ERS condition. The cell proliferation assay was performed using the Microbial viability assay kit. The intracellular H2O2 levels and total SOD activity were detected using the colorimetric method according to the assay kit. The expression levels of endoplasmic reticulum stress target genes, SOD1 and SOD2 were determined by quantitative RT-PCR (qRT-PCR). [Results] We observed significantly higher resistance to ER stress in the SRO9-deletion cells than in wild-type cells. The mRNA expression levels of endoplasmic reticulum stress target genes were up-regulated in the SRO9-deletion strain. The intracellular H2O2 levels, total SOD activity, SOD1 and SOD2 mRNA expression levels were down-regulated in the SRO9-deletion strain. Further more, the SRO9-deletion cells show increased sensitivity to oxidant CHP and VK3, the replicative lifespan also reduced in SRO9-deletion cells. [Conclusion] SRO9 deficiency enhances the resistance ability of the strain to ERS, and these might due to the ER stress responses that triggered by SRO9-deficiency.

Abstract:[Objective] By analyzing the effects of Bacillus subtilis antibiotics, spores and fermentation on the microorganism quantity and microbial community in cucumber phyllosphere, providing theoretical basis for the effective application. [Methods] With cucumber as the experimental material, setting up eight treatments: applying the antibiotics, spores and fermentation before or after inoculating Botrytis cintrea, only inoculating Botrytis cintrea and spraying the sterile water. The experiment was conducted in the indoor. Using the method of traditional microbial separation to count the number, the cultured bacteria, actinomycetes and fungi of cucumber phyllosphere were respectively separated with PB, High’s No.1 and PDA medium. At the same time, analyzing the phyllosphere microorganism samples of different treatments by the Dcode Universal Mutation Detection System for DGGE, the quantitative analysis of strip number and gray level were carried on by Quantity One analysis software, the various belt was clustered by UPGMA method, the microorganism quantity and microbial community was analyzed by microbe richness index, Shannon-Wiener diversity index and Pielou index, the differential DNA sequencing results were analyzed by NCBI Blast program homology, and clustered by The Sequence match program. [Results] The results of different treatments on the microorganism quantity and microbial community in cucumber phyllosphere, showed that spraying before inoculation with the Botrytis cintrea is the best applying way of Bacillus subtilis antibiotics, spores and fermentation, can effectively reduce the number of culturable fungi, increase the number of cultured bacteria and actinomycetes, increase leaf microbe richness index, Shannon-Wiener diversity index and Pielou index. Antibiotic treatment on the occasion of leaf microbial population structure is minimized. [Conclusion] Bacillus subtilis BSD-2 fermentation can reduce the number of culturable fungi. Bacillus subtilis BSD-2 spores can increase the number of the cultured bacteria and actinomycetes. Bacillus subtilis BSD-2 antibiotics can keep phyllosphere microbial richness and diversity index.

Abstract:[Objective] We previously isolated bacterial strains from winter wheat habitats, now, we will screen cold tolerant strains from those isolates and assess their plant growth-promoting potential. [Methods] we screened cold tolerant strains on nutrient agar plates incubated at 4 °C, determined these cold tolerant strains’ plant growth-promoting attributes such as indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase production, inorganic and organic phosphate solubilization and siderophores production, selected strains with good potential according to the assessment system established here, and then tested their plant biomass increase effects at different temperatures based on bioassay experiments. [Results] We screened 34 cold tolerant strains from those isolates. For the selected 8 strains with good potential, the correlation coefficiency indicating coincident relationship between the assessed growth promoting potential and the increase effect on plants in greenhouse condition was more than 0.62. Among them, 1bYB22 and 3bJN2 exhibited more than 28% increase effect on shoot weights of cucumber incubated at 28 °C, and seed bacterization with 1bYB22 and 3bJN2 also increased non-heading Chinese cabbage’s root lengths with 116.76% and 46.82% at 15 °C, respectively. And 1bYB22 exhibited 25.11% increase effect on shoot weights of non-heading Chinese cabbage incubated at 15 °C. Field testing of the 1bYB22 inoculum in wheat also showed significant increase in growth and yield. [Conclusion] Through the screening system established in this study, we obtained cold tolerant P. fluorescens strains 1bYB22 and 3bJN2 from wheat habitat isolates, and these two bacterial strains both exhibited plant growth-promoting effect at 15 °C and 28 °C and promoted the growth of wheat in the field.

Abstract:[Objective] To understand the effects of chlorpyrifos (CPF) on soil bacterial community structure. [Methods] Both cultivable and uncultured bacterial communities were studied by plate method and terminal restriction fragment length polymorphism (T-RFLP). PRIMER-E was used to analyze the data generated by T-RFLP. [Results] At the first 30 days, cultivable bacteria in CPF-treated group were significant different from the control group (P<0.05). The numbers of cultivable bacteria were recovered after the 30th day. Based on the analyzed of T-RFLP data by PRIMER-E, bacterial community was mostly changed (Hae III: C3 (the control group on 30th day), Y0 (the 15 μg/g CPF-treated group on the first day), Z2 (the 150 μg/g CPF-treated group on the 20th day); HhaⅠ: Z0 (the 150 μg/g CPF-treated group on the first day)). ANOSIM indicated that no significant differences were found between different chlorpyrifos concentrations (Hae Ⅲ: Global R=0.041, P=0.168; HhaⅠ: Global R=–0.04, P=0.842), while significant differences were found between different sampling time (Hae Ⅲ: Global R=0.304, P=0.001; HhaⅠ: Global R=0.28, P=0.001). TRF239, TRF240 and TRF241 made the largest contributions to community abundance. Several representative bacterial communities such as Bacillus sp., Clostridium sp., Staphylococcus sp., Sarcina sp., Pseudomonas sp. were achieved by online blasting. [Conclusion] High concentrations of chlorpyrifos will have a great disturbance on soil bacterial community, which will inhibit the growth of rhizosphere bacteria and may suppress the growth of plants. Thus we should reduce the harm caused by repeated use of chlorpyrifos in time.

Abstract:[Objective] Genetic diversity and relationship of 45 Ganoderma resinaceum strains from different areas in China were analyzed. [Methods] We studied clustering analysis and genetic diversity of these isolates using multi-gene analysis with ITS, TEF1-α, LSU sequences and SRAP technique. [Results] 8 pairs of primers on 45 strains were selected and amplificated using PCR-SRAP system, and 95 fragments were amplified, the number of polymorphic bands was 79, the average polymorphic rate was 82.4%. The PIC (polymorphism information content) value of these markers varied from 0.28 to 0.43, averaging 0.38. The results of multi-gene analysis with ITS, TEF1-α, LSU sequences and SRAP technique showed that part of the strains from the same area were clustered with each other, their kinship was close, and some strains with large gaps about the geographical distribution were also clustered in the same phylogenetic tree branch, their genetic relationship may also be relatively close, the result above was consistent with SRAP clustering analysis. [Conclusion] The genetic diversity of 45 strains was relatively abundant, and it had some correlation between genetic similarity and geographical distribution. ITS, TEF1-α and LSU sequences analysis and multi-gene analysis were more useful for classification and identification of Ganoderma resinaceum, and SRAP technique was more suitable for the genetic diversity analysis of Ganoderma resinaceum.

Abstract:[Objective] This study was aimed to obtain a strain which can effectively degrade acetochlor, and to investigate the factors affecting the degradation of the herbicide, so as to provide microbial resources for acetocholor bioremediation. [Methods] By enrichment and separation of culture from the sample, the pure culture was selected from the medium supplemented with acetochlor as the sole source of carbon and nitrogen. The strain in single colony was obtained by means of streak, and was preliminarily identified and classified by Gram staining and 16S rRNA gene sequencing. Effects of initial acetochlor concentration, additional sources of carbon and nitrogen on the degradation of the herbicide were studied by single factor test. Meanwhile, the effects of above-mentioned factors were optimized by orthogonal design. [Results] A strain of Gram negative bacteria was isolated and identified as Pseudomonas sp. Single factor experiment demonstrated that the optimal initial acetochlor concentration for acetochlor degradation was 10 mg/L; the addition of carbon and nitrogen sources could improve the degradation rate of acetochlor. Among them, glucose and peptone was the best carbon and nitrogen source, respectively. The orthogonal design showed that the degradation rate of acetochlor could reach 80.2% under the optimum conditions. [Conclusion] The strain A-1 was able to grow on acetochlor, and the degradation of the herbicide is affected by many factors. This study will provide the strain resources for acetochlor bioremediation.

Abstract:[Objective] To determine the cause of death for Siniperca chuatsi and screen sensitive drugs, a dominant bacteria WJ2014-1 was isolated from the liver of sick S. chuatsi. This study will provide reference for further prevention and treatment of Aeromomas veronii in S. chuatsi. [Methods] The pathogenic bacteria were isolated and purified from the liver of S. chuatsi. And the identification of phenotypic information of the strain WJ2014-1 was conducted, including the biochemical identification and 16S rRNA gene sequence determination. Antimicrobial susceptibility test was conducted by disk diffusion technique. [Results] The results of artificial infection tests by using WJ2014-1 to infect S. chuatsi displayed that the prevalence of symptoms and spontaneous onset symptoms were the same. According to morphological and biochemical characteristics as well as the result of 16S rRNA gene sequence analysis, the isolated strain WJ2014-1 was A. veronii. WJ2014-1 was susceptible to sulfamethoxazole, doxycycline, roxithromycin, cefotaxime, piperacillin and other 21 kinds of antibiotics. Meanwhile, it showed resistance to chloramphenicol, norfloxacin, nalidixic acid and other 9 kinds of antibiotics. [Conclusion] The isolated bacterial strain WJ2014-1 was pathogenic to S. chuatsi, and prevented by administering drugs such as sulfamethoxazole, doxycycline and roxithromycin in fisheries production.

Abstract:Arbuscular mycorrhiza (AM) symbiosis is one of the best known beneficial plant-microorganism associations widely distributed on earth. AM symbiosis plays a vital role in the material cycle of soil ecosystem and also in maintaining the stability of ecosystem. AM symbiosis establishment implies a signal recognition, exchange and transduction between both partners that leads to mutual recognition and development of symbiotic structures. This paper reviews the recent research progresses in signal recognition, exchange and transduction mechanism in the pre-establishment and establishment stages in AM symbiosis, aiming to clarify the signal recognition mechanism in the establishment of AM symbiosis. Furthermore, the review addresses the weaknesses in the current researches and also proposes future research needs.

Abstract:Phytoremediation coupled with plant growth-promoting endophytes (PGPEs) is becoming a new trend in remediation of heavy metal contaminated soil. Compared with rhizobacteria, PGPEs have a more stable living environment and show more intimate relations with host plants, which play a greater value in practical application. Under heavy metal stress, a portion of bacteria could enter plant tissue and become endophytes, which possess superior characteristics in heavy metal accumulation, tolerance and detoxification, coordinating with the heavy metal tolerance system of their host plants. The performances of PGPEs appear in reducing the heavy metal stress intensity in plants directly or indirectly and promoting the heavy metal tolerance system of plants through modulating phenotypes. The role of PGPEs in plant heavy metal detoxification was analyzed systematically and the relevant researches in recent years were reviewed. In addition, the possible ways and research directions were proposed in the interaction mechanisms between PGPEs and plants under heavy metal stress.

Abstract:Microbial fuel cells (MFCs) are receiving wide attentions as a promising method of producing electricity through degradation of pollutants by microorganism. MFCs with photosynthetic bacteria as biocatalyst showed high capability of electricity generation, and achieved multiple functions of sewage treatment, capture of carbon dioxide, conversion of light energy into electricity, as well as recycling of valuable photosynthetic bacteria biomass. Based on the role of photosynthetic bacteria in the system, the ability of electricity production and electron transfer mechanism were reviewed. Moreover, the effects of light on the performance of MFCs inoculated with photosynthetic bacteria were also discussed. Finally the perspective of application of photosynthetic bacteria in MFCs was proposed.

Abstract:Bacterial toxin-antitoxin (TA) systems are formed by a stable toxin and its cognate labile antitoxin, and exist almost in all bacteria. Recently, the chromosome-encoded II-type TA systems have been demonstrated to function as stress-response elements and help bacteria acclimate to different environmental stresses through the action of toxins to various cellular targets. Therefore, the modulation of toxin activities is crucial to II-type TA systems triggering bacterial response to environmental stresses. In this review, we describe the regulation mechanisms of II-type TA system activity, and briefly introduce our recent studies on the regulation of the II-type TA systems in the model cyanobacterium Synecocystis sp. PCC6803.

Abstract:The overuse of antibiotics in medicine, livestock and poultry systems leads to an increase in abundance and diversity of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment, accelerating the environmental dissemination of antibiotic resistance and posing a potential threat to public health. But there is a lack of sufficient information on the current situation of antibiotic resistance pollution in environment, and the relevant research methods need to be optimized and improved. In this paper, we review recent progress of antibiotic resistance in environment, and discuss the collection methods of different environmental (water, soil and air) samples, as well as detection methods for antibiotic resistance—cultivation-based and molecular biology methods (qualitative and quantitative PCR, DNA hybridization and DNA microarray, metagenomics, etc.). The aim is to provide scientific basis and technical support for the research on antibiotic resistance in different environmental matrices.

Abstract:Compared to traditional processing method of minerals, bioleaching is low-cost, easy-operating and low pollutioned and has began to be applied in the treatment of refractory gold ore, low-grade minerals or high-sulfur coal. To make full use of the synergy of leaching bacteria, the present work mainly addressed the synergic advantage and problems during bioleaching comprehensively and the predicted the bioleaching trend in the future. Firstly, the biological characteristics of three important leaching bacteria were analyzed, including Acidithiobacillus ferrooxidans, Leptospifillum ferrooxidans and Acidithiobacillus thiooxidans. Secondly, domestic and abroad research development of bioleaching and its synergic mechanism were also discussed. Finally, possible research prospect and solution of bioleaching technology in two decades was predicted.

Abstract:As the important component of the biology, Microbiology is the basic course of some professions. Microbiology teaching followed the similar classical model which emphasized on the curriculum theory system in different universities. But this model isn’t conducive to the undergraduate’s application ability training in the ordinary universities. Therefore, to make basic course work at full capacity, the author optimized the teaching contents of theory and practice, and integrated the two complementarily. During optimizing, the author regarded the choosing and reordering of experimental project as breakthrough point. All the work based on the construction procedure of microbiological research thinking and practical application.