Abstract:

Abstract:A strain named as WJ44 with capability of producing branched-chain aminotransferase was isolated from the soil, the enzyme activity is especially high when used leucine as a substrate. According to the physiological characteristics, biochemical characteristics and 16S rRNA sequence of WJ44, the strain was identified as Bacillus cereus. The optimal carbon source and nitrogen source were also determined as 20 g/L glucose, 15 g/L tryptone and 5 g/L beef extract, respectively. The optimal proportion of other component in the medium is corn steep liquor 15 g/L, KH2PO4 3 g/L, MgSO4·7H2O 0.5 g/L. The optimum original pH value is 7.0, the cultural temperature is 37℃,

Abstract:A high temperature hydrocarbon-degrading strain, Bacillus sp. A1, was isolated from oil-water samples of ShengLi oil field in Shandong Province. The cell-surface hydrophobicity of A1, emulsification to hydrocarbons and change of the wetting property of rocks treated by A1 were investigated in this paper. Three methods were used to determine the cell-surface hydrophobicity, CAM (Contact Angle Measurement), SAT (Salt Aggregation Test) and BATH (Bacterial adherence to hydrocarbon). The results showed that the cell-Surface of A1 was strongly hydrophobic. The diesel oil can be well emulsified by A1, and the emulsion showed good tolerance to salinity, pH and temperature. The hydrophobicity of rocks surface decreased dramatically treated by A1 and the contact angles of quartz, limestone and glass fell more than 60%. If the hydrophilicity of the rocks is higher, the oil in the rocks could be recovered more easily.

Abstract:A poly-γ-glutamic acid producing strain--BLN-2, was isolated from the soybean products. According to the biochemical characteristics and 16S rRNA, the strain was identified as Bacillus subtilis. Using soybeans as culture, the solid-state fermentation conditions of BLN-2 have been studied. The results showed that the optimal carbon and nitrogen sources of BLN-2 were glucose, fructose, NaNO3 and KNO3, respectively. The orthrogonal experiments showed, when the final concentration of the fructose which was added to the soybean culture was 0.5%, the glucose, NaNO3 and KNO3 final concentraion were 2.0%, the production of γ-PGA was the highest--89.05 g/kg. It is 48.42% higher than other comparable soybean medium under the same conditions.

Abstract:To directly access typeⅠpolyketide synthases (PKS ) gene diversity from soil and seawater, a set of degenerate oligonucleotide primers were designed to amplify the ketosynthase fragments (KSs) belong to the PKS Ⅰ genes from the soil and the seawater DNA samples obtained from the Yangshan Harbor (Shanghai, China). All the unique 23 fragments (ranged from 630 bp to 690 bp after cutting off the primer and vector sequences) obtained were belonging to the conserved KS domains in PKS Ⅰ genes. Among them 19 fragments were amplified from soil (DQ640993, DQ640997, DQ641926, DQ641927, and DQ673137~DQ673151) and 4 from the seawater (DQ673151 and EF554859~EF554861). The predicated amino acid sequences showed 45% to 85% identifies to the known KSs genes in the GenBank. Phylogenetic analysis showed that 14 of them belonged to the normal KS domains that catalyzed the condensation of the acyl groups and the other 9 KS fragments belonged to the hybrid PKS/NRPS groups. Several KS fragments were endowed with some distinct characters that could be used in the following studies.

Abstract:Macrolactins are 24-membered macrolides produced by unidentified marine bacterium, Actinomadura sp. and Bacillus sp., which exhibit both antibacterial and antitumor activities in vitro. The environmental strain X-2 which was isolated from the sediment of the East China Sea produce Macrolatin A, B and O. In this study, a set of degenerate oligonucleotide primers, designed for amplification ketosynthase(KS) domains, had been employed to identify KS gene fragments of the X-2 DNA samples. One 645 bp KS fragment(GenBank accession no. EF486351)had been cloned and used as a probe to screen the genome DNA fosmid library of X-2. Three positive clones were selected and sequenced, Homologous analysis and the function prediction of the obtained PKS gene fragments suggested that macrolactin is the Polyketide Biosynthesis Product of the gene cluster obtained in the environmental strain X-2.

Abstract:12 strains of H2-producing bacteria were isolated and purified from anaerobic sludge, aerobic sludge and river bottom sludge by Hungate method. A new species of high efficient hydrogen production bacterium Enterococcus sp. LG1 (registration number: EU258743 ) was studied deeply. It was showed that the Enterococcus sp. LG1 was an anaerobic and Gram-negative bacterium. Sequence analysis of this type of clones showed that it was affiliated with the genus Enterococcus and it was not reported yet in other paper at present. Meanwhile, batch tests of anaerobic fermentative hydrogen production by Enterococcus sp. LG1 were investigated by using sterilization pretreated sludge as substrate. The changes of soluble COD, protein, carbohydrate and pH value during hydrogen fermentation were monitored. It was found that only hydrogen and carbon dioxide were produced by this strain and no methane was detected during fermentation. The maximal hydrogen yield was 36.48 mL/g TCOD and the hydrogen concentration in the gas phase was 73.5%. The Enterococcus sp. LG1 was a butyrate fermentation bacteria analyzed by metabolites.

Abstract:The concentration of airborne microbes in summer tourism season in Huangshan Scenic Spot was measured by fallen plate method at l4 collection sites. The study on the community structure and distribution characteristics of outdoor airborne microbes was carried out. The results showed that the average concentration of the bacteria, fungi and total microbes in the outdoor environment were 0.41′104 CFU/m3, 0.34′ 104 CFU/m3 and 0.75′104 CFU/m3 respectively, and the average percentage of fungi of the total was 45.9%. These indicated that the outdoor air had been polluted by airborne microbes. The preliminary identification was made on the bacteria and fungi at different sampling sites and the results showed that the dominant bacteria mainly belonged to Bacillus, Staphylococcus, Micrococcus and Pseudomonas, and the average percentage of the total amount of the bacteria was 37.7%, 17.2%, 10.1% and 9.8% respectively; the dominant fungi belonged to Cladosporium, Mycelia sterilia, Penicillium and Alternaria, and the average percentage of the total amount of the fungi were 40.4%, 35.0%, 5.6% and 4.3% respectively. The results indicated that the distribution characteristics of air microbes are affected not only by topographical and climatic characteristics, but also by factors such as tourist activities, animals and plants.

Abstract:In this paper, a slight halophilic alkaliphile strain, Alkalibacterium sp. F26, which produced high level of intracellular CAT observed in previous research, was selected as a model microbial to explain the responses of this bacterium to oxidative stress. The results indicated that Alkalibacterium sp. F26 had obvious responses to higher concentration (>1 mmol/L) of H2O2 than that to lower H2O2 (<1 mmol/L) challenge from the aspects of defensive enzyme synthesis and cofactors level variation. As for catalase production, the activity increased up to 106.54 U/mg protein which was 1.76 fold of the control when cells were challenged by 3 mmol/L H2O2, but its activity only was 1.13 fold when H2O2 was 100 mmol/L. As far as energy state was concerned, ATP production and NAD+ generation were significantly inhibited from 20.55 mmol/L to 17.80 mmol/L and 69.89 mmol/L to 31.77 mmol/L, respectively, leading to the drop of energy charge from 0.77 to 0.68 and the increase of the portion of NADH/NAD+ from 0.08 to 0.41 in the former case. However, these effects were less distinct under lower concentration of H2O2. Except of the condition of 100 mmol/L H2O2, under which the activation of defensive mechanism resulted in an increase of ATP, the level of ATP dropped from 22.69 mmol/L of the control to 22.38 mmol/L and 13.70 mmol/L when challenged by 50 mmol/L and 500 mmol/L H2O2. Besides, the concentration of NADH fluctuated and the NAD+ gradually reduced when H2O2 below 1 mmol/L.

Abstract:The kinase domain of receptor tyrosine kinase(RTK) ErbB2 was expressed fused with GFP in Pichia pastoris. Recombinant expression vector pPIC3.5K was constructed in Escherichia coli TOP10. The right P. pastoris transformants were screened on his-deficient plates and YPD-G418 plates by turns after electroporation of recombinant vector, and then induced by methanol in baffled shake bottles. The strain with highest protein yield was scaled up in a 5 L fermentor. Recombinant protein was analyzed with tyrosine kinase assay after Ni2+ affinity chromatograph. Results showed that the 100 kD recombinant protein with tyrosine kinase activity was successfully expressed in P. pastoris.

Abstract:The screening system of phosphorus solubilizing bacteria in the soil was established by biological enriching using organic phosphobacteria liquid medium and then screening via plate dilution method using inorganic phosphobacteria solid medium. By 16S rDNA sequencing technique, the strain PSB3 with the 16S rDNA gene of 1525 bp length was identified as Burkholderia cepacia by Blastn search in NCBI database. The results of in-door antagonism experiment of PSB3 to 12 strains of Fusarium and Colletotrichum (Fusarium solani et al) showed that PSB3 had antagonism reaction against 6 of the 12 pathogens.

Abstract:The antifungal mechanism of the TS67(Penicillum sp.) producing bioactive metabolites was investigated in this paper. The test indicated that mycelia growth, spores forming and spores germination of Bipolaris maydis and Fusarium oxysporum can be inhibitied by metabolites, after 50% fermentation broth acting 120 hours, the inhibition rate of hyphal growth can reach about 77.78%, 70.30%, the inhibition rate of spores forming also arrived at 58.8%, 73.5%; under 50% fermentation broth acting 12 hours, the inhibition rate of spores germination were up to 78.3%, 62.0%, the mycelia under activity metabolites conditoins also showed surface nodulation and growing point expanding irregularly, protoplasmic condesing, etc. Based on all these results, we may draw a conclusion that activity metabolites maybe target at fungal cell wall.

Abstract:The culture medium and cultural conditions of solid-state fermentation of Streptomyces Men- myco-93-63 were tested in this study. The suitable medium which contains rice, sorghum, millet bran, and rice hull with the proportion of 2:2:3:3 was developed for the spore production of Streptomyces Men-myco-93-63 using single substrate screening, mixture substrate screening and orthogonal experiments, and the sporulation was up to 2.52×109 CFU/g. And then, initial charge, initial ratio of water to solid, inoculating quantity, and culture temperature impact to sporulation of Streptomyces Men-myco-93-63 were tested. The favorite cultural conditions are developed as the following: the initial charge is 15 g in 500 mL Erlenmeyer flask; initial ratio of water to solid is 1.7:1.0 (V/W, rice hull excluding), inoculating quantity is 7 mL, culture temperature is 28℃.

Abstract:The symbiotic plasmid pMh7653Rb of Mesorhizobium huakuii strain 7653R was labeled by Tn5-mob-sacB insertion, the mutant strain 7653RT14 labeled its symbiotic plasmid was obtained . Plasmid curing experiment was carried out using the sacB positive selection method, the derivative 7653R-1 of symbiotic plasmid cured was obtained. Transpositional frequency of transposon Tn5-mob-sacB was higher than 10-5. Cultural characteristics of the mutant derivatives were similar to wild type strain 7653R. The nodulation tests presented that 7653RT14 could form pink effective nodules, the result showed that pMh7653Rb inserted by Tn5-mob-sacB did not lost nodulation ability. However, 7653R-1 lost nodulation ability or only formed a few small null nodules. The results of stability tests indicated that 7653RT14 carrying symbiotic plasmid inserted by Tn5-mob-sacB was stably inherited under the conditions tested, and could be used as donor strain of symbiotic plasmid transfer.

Abstract:An extracellar fibrinolytic strain was isolated from fermented shrimp paste. In addition to general physiological and biochemical properties, the strain was identified by 16S rDNA sequence and systematic analysis. The results showed that 16S rDNA sequence of the strain had high similarity with AY601723 and AB195282, suggesting that the strain is a subspecies of Bacillus sp. It was named as Bacillus sp. nov. SK006 by CCTCC. The medium composition and fermentation conditions for fibrinolytic enzyme production were also optimized in the research.

Abstract:In order to evaluate the immunogenicity and their protection of outer membrane protein of Bordetella bronchiseptica and effective antibody (OMP68, we established a mice model. The research improved on the method of Wooldridge in order to extract OMP of Bordetella bronchiseptica (P13, P11), and the differences of OMP were analyzed by SDS-PAGE. The P13-OMP was analyzed with Western blotting and OMP68 was gained by the way of electrophoretic elution. Then we maked the effective antibodies of P13-OMP. Then P13-OMP, OMP68 and whole-cell bacterin (WCB)immunizing antigen was prepared 70 mice were equally assigned to 7 groups at random. They were immunized by P13-OMP, OMP68 and P13-WCB of different dose respectively. The indirect ELISA was used to detect antibody responses. 80 mice were equally assigned to 8 groups at random. Group a and b were immunized by P13-OMP (25 μg) respectively. Groups c and d were immunized by OMP68(25 μg); Groups e and f were immunized by WCB(P13). Ten days after the immunizations, group a, c, e and f were challenged with P13. The other groups were challenged with P11. Then we registered the rate of protective potency and evaluated protection given by P13-OMP, OMP68 and P13-WCB. Results showed that at 42th day, the titer of serum reach the top: P13-OMP(215.3)> OMP68(214.8). Then, the titer of serum started the slow-moving descent At 70th day, the titer of serum reach the OMP68 (210.2)> P13-OMP (29.1). P13-OMP and OMP68 group challenged with P13 and P11 can be efectivly protected; P13-WCB group challenged with P13 and P11 can not be efectivly protected; the control group were died out. The P13-OMP and OMP68 of Bordetella bronchiseptica has good immunogenicity and protection, so the results of this study lay good theoretical foundation for OMP subunit vaccine.

Abstract:In order to demonstrate the taxonomic position of paramyxovirus Tianjin strain and explore its mechanism of pathogenesis. Bioinformatics methods were used to analyze the deduced amino acid sequences of NP, P, M, and L protein of Tianjin strain. Phylogenetic analysis based on NP, P, M, and L protein sequences demonstrated that Tianjin strain belonged to the genus Respirovirus, in the subfamily Paramyxovirinae and most likely a new genotype of Sendai virus. Sequence similarities comparisons indicated that Tianjin strain P protein was poorly conserved, sharing only 78.7%~91.9% amino acid identity with 6 known Sendai viruses, while L protein was the most conserved, having 96.0%~98.0% amino acid identity with other Sendai viruses. Multiple-sequence alignments of Tianjin strain NP, P, M, and L protein with those of 6 known Sendai viruses showed that Tianjin strain possessed a lot of unique amino acid substitutions in protein sequences, 15 in NP, 29 in P, 6 in M, and 29 in L. The presence of these unique amino acid substitutions suggests that Tianjin strain maybe has a significant difference in host or pathological characteristics from the known Sendai viruses.

Abstract:Total 149 strains of endophytic bacteria were isolated from different healthy organisms of Glycyrrhiza inflata Bat. from Xinjiang. The fermented liquids of these strains were screened by TLC and analysed by HPLC, and the glycyrrhizinic acid monoammonium salt was taken as standard control at the same time. Only one endophtytic bacterial stain of Bacillus subtilis could produce Glycyrrhizinic acid monoammonium salt analogue.

Abstract:A strain, producing a fibrinolytic enzyme, was isolated from the nature environment by using blood powder plates gathering and fibrin plates screening, and was named ML909. All results from morphological, physiological and biochemical characterization, the 16S rDNA sequence and phylogenetic assay identified that the strain belongs to Micrococcus luteus. The DNA fragment encoding mature peptide of fibrinolytic enzyme was cloned by PCR and sequenced. The gene sequence was registered in GenBank of NCBI and the accession number is EU232121.

Abstract:Based on the strain of Micromonospora carbonacea JXNU-1 with board-spectrum antimicrobial activity, the technology for the isolation and purification of antibiotic from the fermentation broth of the Micromonospora carbonacea, and its physical-chemical properties were studied. The results showed that, the antibiotic was stable under the condition of high temperature and alkali, but not in acid solution. After the pretreatment of centrifugation and filtration to remove the cells and lipids, the antibiotic was absorbed to negative exchange resin, and the impurity was excluded when 2 mol/L NaCl was used as primary eluent. The antibiotic could be eluted with 20% alcohol as eluent, and the eluting speed of the antibiotic was greatly accelerated as 2 mol/L NaCl was added into 20% alcohol as final eluent. Aqueous solution of the antibiotic was yielded from the alcohol-salt eluant by decompression concentration to wipe off alcohol and by dialysis to exclude salt. One active component was detected in antibiotic solution by paper chromatography, and the HPLC purity was over 99%. As the antibiotic shows positive color-forming reaction to Molish reagents, Benedict’s reagents and Diohenvlamine reagents, combined with the characteristics of absorption spectra, it is deduced that the antibiotic belongs to nucleoside antibiotics.

Abstract:Seventy-two strains of endophytic fungi were isolated from the healthy bark, branches and leaves of Cephalotaxus hainanensis L.. Sixty-eight of them were morphologically classified into Fungi Imperfecti, thirty-three sporulated were identified to five genera. For those did not sporulate, one was identified to Rhizoctonia sp., the rest were tentatively classified into Mycelia Sterilia. Four were identified to Basidiomycetes. The result indicated the endophytic fungi of C. hainanensis show a degree of tissue specificity. There were significant differences about the quantity, genera and composition between the fungi isolated from bark and those from branches and leaves.

Abstract:Lactobacillus plantarum was treated with UV, the exhibited good stability obtained by a screening to tow mutants with cholesterol gradient plate and Cholesterol-degrading testing in vitro. Among which the rate of Cholesterol-degrading of Lp-UVs 29 and Lp-UVs 44 are respective 48.7% and 44.2%, which raise respectively by 97.97% and 79.67%.

Abstract:Microarray technology, used in microorganisms detection with its advantages of rapid detection, high sensitivity, high-throughput and low cost, has been applied in environmental microbial community research widely in past few years. It focuses on investigation of structure, diversity, function, dynamics of microbial populations within complex environmental samples. Furthermore, it also reveals their responses and adaptation to environmental perturbations such as climate change, toxic contaminants. According probe design patterns, several types of microarrays, such as phylogenetic oligonucleotide arrays (POAs), functional gene arrays (FGAs), metagenomic array(MGA) and community genome arrays (CGAs) have been constructed for environmental studies. This review discusses applications of microarrays to environmental microbial populations research along with its potential for screening of specific microorganisms, gene or expression functional gene representing different environmental microbial populations.

Abstract:Microbial technology is a potential new technology in new energy development process and it has important theoretical and practical significance on the sustainable development of energy sources. The principles, present situations, advantages and disadvantages of new energy sources, such as biodiesel, fuel ethanol, biological methane production, biological hydrogen production and microbial fuel cell were reviewed. The applications of microbial sources in energy field were summarized. Finally, some research emphases such as discover new microbe sources, construct gene engineering microbes, definitize effect mechanism and exploit new technologies were given.

Abstract:Multidrug-resistant Salmonella has become a public health and economic problem worldwide. Antibiotic resistance in bacteria can be caused by gene mutation, overexpression of efflux pumps, and mobile genetic elements such as plasmids and integrons that carry genes encoding enzyme(s) that inactivates or modifies antibiotics. This review focuses on research progress related to elucidating mechanism of antibiotic resistance in Salmonella.

Abstract:Coniothyrium minitans Campbell is a ubiquitous antagonistic fungus of Sclerotinia sclerotiorum (Lib.) de Bary, which is an important widespread plant pathogen. Many researches indicated that C. minitans had great potential in controlling Sclerotinia diseases caused by Sclerotinia spp. in green houses and fields. In recent years, there have been crucial advances for this fungus at the molecular level. In order to promote further research, the present advancement on the molecular biology of conidiation, interaction with host, transformation, detection and genetic diversity are summarized and existing problems are discussed.

Abstract:The practice of English teaching of microbiology course using the original edition of Microbiology (Prescott LM et al., 5e, 2002) as textbook have been carried out for two years for undergraduate students majoring in Biology. The strengths of this book are comprehensive coverage, flexibility of organizing, and emphasis on the enhancing the overall ability of students. Its content is excellent with fundamental knowledge, systematic arrangement and up-to-date currency, which helps instructor to construct a suitable system in the course structure and curriculum, as well as to enrich the teaching content and to increase teaching effectiveness. The selection of original edition of English textbook in microbiology course is useful to train high-quality biological talents possessing international view and the adaptive ability of globalization process.

Abstract:PBL is a modern model of classroom teaching. We have introduced it into the teaching of Microbiology. As a result, the students’ learning abilities have been raised to a higher level, and their learning autonomy and achievement have been improved. The combination of PBL method with traditional teaching methods achieved a good effect.

Abstract:To cultivate applied capability of bioengineering students, five aspects should be done: optimization of experiment teaching system, reformation of experiment teaching mode, intensifying management of experiment teaching, increase of new experiments related tightly to scientific research, and training students’ self-study capability.

Abstract:To improve the efficiency of halophilic actinobacteria screening and carry out the rapid selection of targeted strains, we tested 34 strains of Streptomonospora by PCR-single strand conformation polymorphism analysis (PCR-SSCP) based on genus-specific primers for the PCR identification. This approach employs PCR with two pairs of primers located in the 16S rRNA sequence flanking two variable region, then build clustering tree according as SSCP data. Synchronously, we sequenced all the 16S rRNA partial sequences for these strains to verify them. The results showed that the PCR-SSCP analysis was an efficient, easy-to-handle and economic method for rapid selection of halophilic actinobacteria resources.

Abstract:Four kinds of colophony were used to isolate the herbicidal substance from the toxin produced by isolate PAM1 of Pythium aphanidermatum, which had herbicidal activity to Digtaria sanguinealis L and the results showed X-5 was the best one for absorbing herbicidal substance among the four kinds of colophony used. Four solvents including 50% ethanol, 95% ethanol, ethyl acetate and acetone were used as eluting solvent and 2 procedures were tested, and the results of growth inhibition and seed germination indicated that the best eluting procedure was procedure 1.