Abstract:

Abstract:The lipase-producing strain ZYB002 with broad-spectrum organic solvent-tolerance was identified as Burkholderia cepacia complex by the recA sequence. The optimal pH and temperature for lipolytic activity of the cell-bound lipase from Burkholderia sp. ZYB002 was 8.0 and 65°C, respectively. It was stable at temperature up to 70°C and retained 79.2% of its original activity for 1 h. The lipase was highly stable in the pH range from 3.0 to 8.5 for 6 h. Ca2+, K+, Na+, NO3?, etc. ions stimulated its lipolytic activity, whereas Zn2+ ions caused inhibition. The cell-bound lipase was also relatively stable in n-butanol at a final concentration of 50% (V/V) for 24 h. However, the lipase was strongly inhibited in triton X-100 at a final concentration of 10% (V/V). The cell-bound lipase with thermal resistance, alkaline resistance and organic solvent resistance showed its’ great potential in various industrial application fields.

Abstract:A facultative anaerobic butanol producing bacteria named C2 was isolated from soil planted with rehmanniae. C2 could produce 17.17 g/L total solvent (acetone, butanol and ethanol, ABE) in a 7% corn mash and the butanol yield reached 11.2 g/L amounting to 65.2% of the total solvent. Using corn straw hydrolysate as raw material (total sugar 25 g/L), 3.64 g/L total solvent was produced, among which 72.3% was butanol, reached to 2.63 g/L. According to the analysis of morphology, physiological and biochemcal characteristics and 16S rDNA sequence, this bacteria strain was identified as Bacillus sp., and was most related to B. vallismortis, B. Atrophaeus and B. mojavensis.

Abstract:Using Vibrio cholerae seperated from the intestines of abalones as host, ten bacteriophages of Vibrio cholera were isolated by double-layer plate method from sea water sample from the Red tide at Dameisha of Shenzhen in 2004. Three broad lysis spectrum strains were found by detecting microbiological assay, RTD, the character of plaque morphology under electron microscope and the lysis spectrum. PsaA and PsaH were selected among all the strains as the representation to study the biological characteristics. The results proved that heat inactivation, pH, ultraviolet rays and sodium citrate restrict the ability of lysis to some dgree, additionally, magnesium perhaps have advantage on lysing. Furthermore, this study provide us further theory of researching on microbial ecological agents for eliminating Vibrio cholerae and diagnosising on food borne Vibrio cholerae using bacteriophage.

Abstract:In this paper, a batch laboratory test was conducted to study the degradation of 2,4,6-trichlorophenol (2,4,6-TCP) using an integrated microbial-Fe0 treatment system under nitrate-reducing conditions. The changes of pH, nitrate concentration, nitrate-reducing activity were detected under different nitrate concentrations. Results showed that the degradation of 2,4,6-trichlorophenol at an initial concentration of 20 mg/L was significantly inhibited under nitrate-reducing conditions. And 2,4,6-trichlorophenol removal efficiency declined and nitrate-reducing activity raised with the increase of initial nitrate concentration. Nitrate is reduced in this system followed by the reductive dechlorination of 2,4,6-trichlorophenol.

Abstract:Acidobacteria is widely distributed in the nature and plays important roles in various ecosystems. In this study, soil samples were collected from Xishuangbanna Tropical Forest. Community DNA were directly extracted and amplified with the specific primers targeting the 16S rRNA genes of Acidobacteria to construct 16S rRNA gene libraries. The random clones from the libraries were screened and sequenced. Phylogenetic relationship of Acidobacteria in this specific ecosystem was built up. The results showed that members of the identified Acidobacteria belonged to five major groups: Gp1, Gp2, Gp3, Gp5 and an unclassified Acidobacterium. Among them, Gp1 was the most predominant group, about 50%-80%, Gp2 was followed by 12%-25%. Among the samples, the community structure of Acidobacteria was consistent. This study discovered the high diversity of Acidobacteria populations distributed in the soil ecosystems to adapt their specific environments.

Abstract:A bacterial strain, A45, with antagonistic activity against Salmonella was isolated from Salmonella-contaminated soils, which was identified as Alcaligenes sp. by checking the individual morphology, colony characteristics and 16S rDNA sequencing. The inhibiting effects of A45 to Salmonella in soils were investigated by field and greenhouse pot experiments respectively. The amounts of Salmonella in soils decreased up to three orders of magnitude after spraying A45 into soils both under greenhouse and field conditions. It suggested that it might be an effective, economical and environmentally friendly approach to apply A45 for in-site remediation of pathogens-contaminated soils.

Abstract:A total of 67 strains of endophytic fungi were isolated from roots, branches and leaves in Dendrobium officinale. These strains were identified into 16 genera based on morphological characters and ribosomal DNA(rDNA) sequence analysis, thereinto Fusarium and Alternaria are dominant populations in D. officinale. From analysis results we found some endophytic fungi show a certain degree of host and tissue preference. The research provided theoretical basis for developing and utilizing the resources of endophytic fungi in Dendrobium.

Abstract:A novel bacterium strain, designated ge21, was isolated from the internal tissue of ginseng root. Its taxonomic position was discussed and its antibiotic activity against pathogenic fungi and Oomycetes was evaluated in this study. The strain ge21 had the highest sequence identity with Paenibacillus granivorans (96.89%). On the basis of its phenotypic properties and phylogenetic distinctiveness, the strain ge21 was identified as a latent novel species of the genus Paenibacillus. The antagonistic effects showed that ge21 expressed antibiotic activity on Fusarium oxysporium, Phytophthora parasitica, Colletotrichum agaves, Alternaria longipes, Pyricularia oryzae Rhizoctonia solani, Phytophthora cactorum and Sclerotinia schinseng to some extent.

Abstract:E. coli DH5α △asd deletion mutant was constructed by using Red recombination system. First, the chloramphenicol resistance(cat)gene flanked by homology extensions of asd gene was amplified by PCR. The PCR products were electro-transformed into E. coli DH5α strain, with the help of Red recombinant system, the most part of asd gene was in vivo replaced by homology extensions connected with cat gene. E. coli DH5α (△asd::cat)deletion mutant with cat gene was selected by LB plate with DAP and chloramphenicol. The cat gene was then eliminated by using a helper plasmid, pCP20, en-coding the FLP recombinase; the mutant for the recombinant E. coli was named E. coli DH5α △asd which lost the capability of growth on LB plate. The deletion mutant recovered the capability of growth on LB plate when added with DAP component. The function of the asd deletion mutant also could be compensated by the plasmid expressing asd gene. There were no significant difference in the key charac-ters of growth speed, growth log phase, accepting different origin plasmids with high efficiency between E. coli DH5α and E. coli DH5α △asd mutant. Based on the DH5α △asd mutant, the chromosome-plasmid balanced-lethal system was set up successfully, which was stable for 50 generations of passage culture in vitro and expressed the FedF adhesin without antibiotic resistance gene.

Abstract:As an important signaling molecule, protein kinases participate in signal transduction by phosphorylating target substrates, and play important roles in the processes of perceiving environmental stimuli, cell differentiation and fungal growth. By using 3′RACE and TAIL-PCR, a protein kinase gene named omk1 (GenBank accession number: EU479712) was cloned and characterized from mycoparasite fungus Ol-pitrichum tenellum. The omk1 gene encodes 355 aa and contains two introns (57 bp and 73 bp, respectively). Phylogenetic analysis indicated that OMK1 is most similar to other fungal FUS3/KSS1-type MAP kinase and has signature sequences characteristic of serine-threonine kinases. RT-PCR analysis showed that the gene omk1 transcribed in the phases of both spore germination and hyphal growth.

Abstract:In this paper, a mycovirus was isolated from an edible mushroom, Lentinus edodes, in China. The virus particle is bacilliform with a size of 20 nm× (100?200) nm and contains a dsRNA genome about 8.0 kb. A fragment with 1457 bp of virus genome cDNA was cloned and sequenced (Accession No. GQ372842). This partial genome sequence has no obvious homology with known nucleic acid sequences in GenBank, which suggested that the virus may be a novel mycovirus. To detect the virus from Lentinus edodes in laboratory or field, we developed a convenient and effective RT-PCR method. With this method, the specific RT-PCR product was successfully amplified from the abnormal mycelia.

Abstract:The condition of protoplast preparation and regeneration of Monilia fructigena was studied in this research. The results showed that the composition of cell wall degradative enzymes, liquid medium, mycelial age, digesting temperature and time duration affected the preparation of protoplast. More proto-plast of M. fructigena were yielded when mycelia incubated in Fries(1/2) for 24 h were digested by en-zyme mixture of 10 mg/mL driselase, 20 mg/mL snailase, 5 mg/mL celluase and 10 mg/mL lysozyme for 4 h at 28?C. The protoplast regeneration rate was affected by osmotic solution, solid regeneration medium, and digesting time.The best regeneration of protoplast of M. fructigena was achieved by using STC as isotonic solution and Fries(1/2) solid medium as regeneration medium. The regenerated strain of M. fruc-tigena was same as original strain in colony morphology and pathogenicity.

Abstract:NS3 gene fragment (about 2000 bp) was amplified by PCR from plasmid of pPOHCLV containing Hog Cholera Lapinized Virus (HCLV) cDNA, and cloned into the prokaryotic expression vector pET-32a (+) to obtain the recombinant prokaryotic expression vector pETNS3. The pETNS3 was transformed into E.coli Rosetta (DE3) and expressed optimally. The recombinant protein NS3 about 95 kD was detected by SDS-PAGE and expressed mainly in the form of inclusion bodies. The result of Western blotting showed recombinant protein NS3 has immunogenicity. The nickel affinity chromatography was employed to purify the target protein, and purified recombinant protein NS3 (90%) was obtained. An indirect ELISA was initially established to detect antibody against CSFV NS3 protein, and 221 sera samples of pig from different herds and ages were tested. The result was compared with CSFV-Ab test kit of IDEXX, and the result showed: the positive coincidence rate was 83.33%, the negative coincidence rate 89.38%, and the total coincidence rate 86.34%. 30 serum samples showed inconsistent, and were detected by Indirect Immunofluorescence Assay (IFA). The results showed: compared with IFA the accuracy rate of result detected by NS3 indirect ELISA and CSFV-Ab test kit of IDEXX was 56.67% and 43.33% respectively.

Abstract:The aim of this study was to isolate and identify moderately halophilic bacteria from solar saltern and to investigate their potential antimicrobial and antitumor activities. Halophilic bacteria were isolated from Ludaokou Solar Saltern in Weihai of Shandong Province. The identification of the strain whb45 was determined by their morphological characteristics, physiological and biochemical tests and phylogenetic analysis based on 16S rRNA sequence comparison. The antimicrobial activity and cytotoxic activity were screened. Our results showed that the strain whb45 was belonged to moderately halophilic bacterium. Phy-logenetic analysis showed the strain whb45 had a 99% homology with Halobacillus trueperi. The crude ex-tract from whb45 showed stronger antimicrobial activities which could inhibit the growth of several bacteria and fungi. MTT analysis revealed that the strain possessed potent anticancer activity with the stronger in-hibitory effect on several human cancer cells. Our results suggested that the moderately halophilic bacterium whb45 may be developed as a potential new source for the discovery of novel bioactive substances.

Abstract:Response surface methodology (RSM) was employed to optimize culture medium for lipid production of Saccharomyces cerevisiae. Firstly, according to the results of mono-factors experiment, a Plackett-Burman design was used to investigate the effects of different factors in the ferment medium, three statistically significant factors are:citric acid, CaCl2, initial pH value, and then steepest ascent procedures was employed to define optimal response region for these three factors. Finally, Box-Behnken was employed to design. The results of experiments was analyzed by RSM with Minitab15.0 soft. The optimal lipid production medium is: glucose 15%, peptone 0.2%, yeast extraction 0.4%, citric acid 0.471%, MgSO4?7H2O 0.1%, ZnSO4?7H2O 0.2%, CaCl2 0.025%, FeSO4?7H2O 0.005%, initial pH value 6.74, 180 r/min, incubme in 30?C for 96 h. Lipid production (dry weight) after optimization is increased from 4.76% to 14.55%. The yield of lipid is increased by about 3 times.

Abstract:The conversion of residual oil to natural gas by anaerobic microorganisms could substantially improve the exploitation and utilization of oil resources. The recovery of methane gas as an alternate form of energy from unrecoverable crude oil may offer a route to economic production of energy from petroleum reservoirs. This review summarizes recent progress about microbial communities, reactions thermodynamics and kinetics involved in the anaerobic biodegradation of petroleum hydrocarbons and the subsequent conversion to methane gas. The feasibility and potential for energy recovery via methanogenesis of residual oil is also discussed. Furthermore, we provide new insights for further studies about this forefront technology.

Abstract:Numerous virus families utilize endocytosis to infect host cells, mediating virus internalization as well as traf?cking to the site of replication. The endocytic pathways utilized include clathrin-mediated endocytosis, caveolae, macropinocytosis and non-clathrin, non-caveolae pathways. The tools to study endocytosis and, consequently, virus entry are becoming more effective and speci?c as the amount of information on endocytic component structure and function increases. Now, the use of inhibitory drugs, although still quite common, often leads to non-speci?c disruptions in the cell. Molecular inhibitors in the form of domi-nant–negative proteins and siRNA have surpassed the use of chemical inhibitors in terms of speci?city to in-dividual pathways. This review focuses on the experimental approaches taken to examine virus entry and provides some examples on a variety of virus families.

Abstract:The critical thinking is an ability to value the theory and the objective existence according to the full reason and objective facts. The critical thinking training for the students not only can help them to improve the ability to adapt to the information society, but also can cultivate their creative spirit and ability. In Microbiology teaching, the ways to train the students’ critical thinking are as follows: Studying the contents of teaching, cultivating the critical spirit. Designing the open exercises, encouraging the creative thinking. Setting the debating activities, training the critical skills. Offering the evaluating opportunities, improving the evaluating abilities.

Abstract:The experience in bilingual teaching of Principles of Gene Manipulation was introduced in this article. In the teaching process of the course, training the students with practical application techniques was emphasized to cultivate the international and application-oriented professionals by consulting the pedagogical experiences of colleges in the USA and UK. The model of bilingual teaching, task-guiding and step practice was established to facilitate the students to adapt to different situations and working condition after their graduation.

Abstract:The human-oriented education is the central idea of scientific development view. According to the characteristics of the bioengineering students, this paper presented the reform and practice on the teaching method of Microbiology, including guiding ideology, teaching content and teaching method. The teaching practice proved that the new pattern of Microbiology education not only stimulated students’ interest in studying the course, but also developed their creative capability and the comprehensive quality. So it meets the demand of social development during the new period.

Abstract:This paper described the results of interactive teaching methods on courses of Microbiology (including Biology of Microorganisms and Fungal Taxonomy) in State Training Base for Fundamental Research and Teaching of Biological Sciences. The scientific research seminar, writing thesis on special topics, and the opening examination could increase the interests of the undergraduates and promote their abilities on technique in microbiological field.

Abstract:In the paper, taking screening and preliminarily identification of amylase-producing strain as an example, tips on exploratory experiment teaching were summarized base on microbiology teaching experience. The paper provides reference for reform of microbiology exploratory experiment teaching.

Abstract:By combining with curricular contents of microbiol ecology, optimized project integrating curricular emphasis and frontier of knowledge was set up according to the research progress on the mechanism of aerobic denitrification and the application of aerobic denitrifying bacteria in denitrification wastewater treatment process. As a prerequisite, to keep the teaching hours in classroom, method of extra-curricular studying based on curricular teaching improved the effectiveness of microbiol course by the example of de-nitrification teaching. This method is the effective way to the training of applied and innovative talents.

Abstract:Teachers were a focus of attention in traditional teaching mode, but students became the leading actor in constructivist teaching mode. There were many disadvantages in medical microbiology teaching, for example lesser hour, more information and lacking logicality, so the better teaching effect was not obtained in teaching medical microbiology with traditional teaching mode. We applied a theory of constructivism to medical microbiology teaching practice and designed constructivist teaching mode for medical microbiology teaching, which inspire students with go-aheadism and creativity. The teaching quality and students general ability can be improved with constructivist teaching mode in medical microbiology teaching.

Abstract:To explore activities of hobby groups in the experimental medical microbiology, helped to expand students’ vision, enhance their interest, stimulate their innovative passion, cultivate their analysis and problem solving abilities in medical microbiology, and boost students’ active study, cooperation study and investigate study.

Abstract:Biogenic amines are produced by some lactic acid bacteria of decarboxylase activities which are potential risk factors for lactic acid bacteria-fermented foods. In this paper, the biogenic amine-producing capacities of 61 lactic acid bacteria strains were analyzed on a decarboxylase medium. Then the methodology of RT-HPLC determination for biogenic amines in fermented broth and milk was studied. The biogenic amines in test samples were extracted by 10% trichloroacetic acid and then derived with benzoyl chloride. The HPLC analysis for the samples were conducted as the following condition: mobile phase was a gradient elution program of methanol and water, the flow rate was 0.8 mL/min. UV detector was used in the final de-termination on 254 nm. The results showed that biogenic amines were separated well on such condition. The method was in a linear way for the amines studied at given concentrations (R2 > 0.995). The average recov-ery ratios ranged from 97.92%?101.14% for all samples. The RSDs were less than 5%. It can be seen that the RT-HPLC method was rapid, stable, high sensitive. Combination of this HPLC method and microbial primary screening on a decarboxylase medium could evaluate the biogenic amine-producing capacity of lac-tic acid bacteria more accurately.

Abstract:Microbe populations from chicken intestinal were analyzed by PCR-DGGE. DNA fragment represented by a band from DGGE gel was retrieved. DNA fragment was two times repeated analyzed with PCR-DGGE, furthermore PCR reamplification and using high-fidelity DNA polymerase amplification also be applied to study on causes of multi-bands in PCR-DGGE analysis. The results showed that the causes of multi-bands in PCR-DGGE analysis may be that DNA templates for PCR mixed with other DNA fragment, and it was difficult to eliminate phenomenon of multi-bands in PCR-DGGE analysis. While the DNA fragments represented by bands from DGGE gel was sequenced, cloned this DNA fragments and extracted plasmid DNA of positive bacteria, and the plasmid DNA was amplified and analyzed again on DGGE gel to verify its position. Colonies whose positions were the same with the original DNA were selected for DNA sequencing to improve the veracity of DNA sequencing.