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Abstract:A strain was isolated from internal organ of died porcine about 8 weeks with purulent pneumonia, arthritis, pyogenic arthritis and endocarditis in April 2007. Objectives of the study are to confirm the genus of the strain, pathopoiesis, and drug sensitivity. The mainly study methods: the first, the strain was identified by the phenotype and the characteristics of the biochemistry, sequence 16S rDNA genes of the strain was analyzed by molecular biology technology, finally animal experiment and drug sensitivity testing were done. The results of the phenotype and the characteristics of the biochemistry showed that it is greatly similar to Actinomyces hyovaginalis, 16S rRNA sequence analysis exhibited the homology achieved to 99.2% compared with group III strains of Actinomyces hyovaginalis, and the phyletic evolution analysis also indicated that it has mostly relationship with group III strains of Actinomyces hyovaginalis. Animal experiment discovered it has highly pathogenicity to Mus musculus albus; Drug sensitivity testing showed that it is hypersensitive to Erycin, Gentamicin and Amikacin. So, the result of the study confirmed that the strain is Actinomyces hyovaginalis III with the pathogenicity.

Abstract:Three strains of mycelial fungi, Alternaria sp., Penicillium sp. and Pestalotiopsis sp., high- frequently isolated from litter of Pinus sylvestris var. mongolica were as the research strain,, the current deciduous needles were as the active zymolyte, the method of fermentation was used to assay the mass defect of zymolyte and the activies of enzymes including laccase, manganese peroxidase (MnP), carboxymethyl cellulase (CMCase) and filter paper activity (FPA) in fermenting process, and try to comfirm the relationship between the activities of enzymes and the mass defect of zymolyte. The results show that the mass defect of zymolyte caused by Alternaria sp. is the highest. Alternaria sp. can produce highest activity of Laccase, CMCase and FPA. Penicillium sp. can produce highest activity of MnP. The three strains of mycelial fungi are all belong to lignocellulose-decomposing fungi of the group of functional fungi.

Abstract:A strain of high-efficiency bioflocculant-producting bacteria, which was named TJ-3, was screened from sewage sludge. The strain was gram-negative and rod-shaped in physiological biochemical test and was identified as Pseudomonas aeruginosa by 16S rDNA Sequencing. According to the growth curve of the TJ-3 strain, the growth stabilization period is long so that Microbial Flocculants (MBF) production is stable. The MBF produced by the TJ-3 strain is able to flocculante kaolin suspension with 98.2%. The MBF activity distribution tests show that most of the active components of the bioflocculant exist in deposition after centrifufation. When pH is 8.5, 1% (quality fraction) CaCl2 Solution dosing quantity is 3.5 mL, bioflocculant dosing quantity is 1.5 mL in 100 mL kaolin suspension, the bioflocculant has an optimal flocculation.

Abstract:A salt-tolerant strain GYW capable of decolorating azo dye was isolated and identified as Halomonas sp. by 16S rDNA. The result showed that the decolorizing salt-tolerant bacteria could survive above the 10% salt concentration and it could decolorize many dyes. The strain had a high decolorizing rate on acid red GR under the condition of pH 7.5, anaerobic 30°C and 10% NaCl. The ion of Cl- strong inhibited the decolorization of acid red GR, and the ion of SO42- affected little on the decolorization, and the lycine addition with the optimal concentration of 200 mg/L could enhanced the decolorization rate under high NaCl concentration.

Abstract:A species-specific oligonucleotide sequence was screened from the third variable domain of 16S rRNA gene of Thiobacillus denitrificans. It confirmed that the sequence had the high speciality by amplifying the activated sludge DNA in high simultaneous biological removal of sulfate and nitrate process and further determining the sequences of 16S rRNA gene clone library. The Cy3-labeled species-specific probe hybridized well with activated sludge and obtained good picture under the conditions of 48°C, 35% formamide deionized, and 100 mmol/L NaCl. ImageJ software demonstrated that T. denitrificans counted for 15% of bacteria in the sludge. The proposal of species-specific primer and probe for T. denitrificans would play an important role in disclosing its temporal and spatial distribution, structure dynamics and realtime quantity.

Abstract:After constructed a 3D-Model and make the multiple sequence alignment of amino acid sequences of trehalose synthase from Meiothermus ruber CBS-01, we performed site-directed mutagenesis of D200G/H165R, R227C, R392A. And the ablity of convertion was detected. D200G/H165R and R392A lost their activities basically, while the ability of convertion of R227C declined at 50°C. When reacted at 37°C, D200G/H165R lost its activity, while R392A and R227C dropped their ability. At last, we found that R392 and D200 had important role on activity of enzyme, while R227 had little affection.

Abstract:The biological characteristics of Bipolaris sorokiniana strain NJ-08 and herbicidal activity its metabolites was tested. The results showed that NJ-08 displayed excellent pathoginicity and high sporulation. The optimum temperature and pH for mycelial growth was 25°C and 8 respectively, the lethal temperature was 55°C maintaining 10 min, the glucose was the best among carbon sources for mycelial growth but all nitrogen source did not significantly promote mycelia growth. For sporulation, the optimum temperature and pH was 25°C and 8, the glucose was the best carbon sources and NaNO3 was the best nitrogen sources. For spore germination, the ranges were temperature of 20°C~35°C and pH of 5~7, while D-xylose was the best carbon sources and peptone was the best nitrogen sources. The metabolites produced by NJ-08 strain made the leaves of Eleusine indica yellow and wilting, and showed good herbicidal activity against the indicator plant and weeds such as Stylosanthes guianensis, Urena lobata, Crotalaria mucronata and Capsicum frutescens with the inhibition rate to radicel and embryo of above 90%.

Abstract:By means of comparing biomasses of biodegradation fungi, Fusarium sp. HG-P-01 for β-cypermethrin, a synthetic pyrethroid insecticide used widely in China, in five different media, the Czapek-Dox medium was selected as the best medium for mycelia growth. Furthermore, an experiment of central composite rotatable design (CCRD) was used to optimize the content of nutrient components. The optimal composition of C, N and P in media for HG-P-01 were 20.94 g/L, 1.82 g/L and 1.66 g/L, respectively, in which an expectant or real rate of β-cypermethrin-degradation got to 96.34% or 93.78% by HPLC for a concentration of 50 mg/L after 24 h treatment. The predicted value in degradation rate model was consistent with that from HPLC method.

Abstract:Relationship between bacterial wilt of ginger with its soil biodiversity of freshly plowed soil, continuous cropping soil of ginger and continuous cropping soil receiving ecologically organic fertilizer (EOF) was studied by Random Amplification polymorphic DNA (RAPD) method. The results showed that ginger wilt did not occur in freshly plowed soil, while the ratio of ginger wilt was 100% in continuous cropping soil, and reduced to 37% when the continuous cropping soil receiving ecologically organic fertilizer. The soil microbial number of Fungi, Actinomyce is increased in continuous cropping soil receiving EOF, but a few changes of bacteria were found, as the varieties of strains in vitro were increased obviously. The simpson index, Shannon index all greatly increased after adding the EOF, which was similar to those in freshly plowed soil. The DNA sequence diversity of soil microbial communities was affected by EOF. The band of random amplification analysis showed a lot of amplification DNA bands in continuous cropping soil receiving EOF, and the distinctness that didn’t exist in continuous cropping soil emerged. The results of study suggest that applying EOF can enrich or decrease some microbial species in soil. It may also increase soil biodiversity and exhibit beneficial to suppress soil – borne pathogens on ecological level.

Abstract:Alteration of cell membrane permeability is speculated to be one of the damage mechanisms to Lactic Acid Bacteria during freeze-drying. It has been reported that the H+ and Ca2+ alteration may be accurately detected by using fluorescent probe. The Lactobacillus bulgaricus permeability is studied by using fluorescent probe BCECF-AM and Fluo3-AM. The membrane permeability has a significant increase which is anti-related to the loss of vitality. These results suggest that alteration in cell membrane permeability contributes to the physical damage, it may be one of the reasons that lead to the cell death and loss of activity.

Abstract:60 strains which have antimicrobial activity had been isolated from nutritious soil in China in the study. We have further selected 1 strain which product broad-spectrum antibiotics using agar well-diffusion method. The strain was identified Brevibacillus laterosporus after physiological biochemical characteristic experiments, sequencing of 16S rDNA and cluster analysis, named S62-9.

Abstract:Using real-time PCR to detect the effect of supplementing with Malic acid and stearic acid on rumen main functional microbe, including ciliate protozoa, methanogen, cellulolytic bacteria, hydrogenated bacteria and lipolysis bacteria in vitro. The result showed there were significant effect on the quantities of Anaerovibrio lipolytica, which decreased 95.8%(P<0.001), and Fibrobacter succinogenes, which increased 52.5%(P<0.05) after supplemented with Stearic Acid. The quantities of Anaerovibrio lipolytica were decreased by 91.2%(P<0.001) on 5 mmol/L MA group and 94.8%(P<0.001) on 10 mmol/L MA group, and the latter were decreased 41.3%(P<0.05) than the former. The conclusion was stearic acid and malic acid were significantly effected on part of rumen microbe respectively, however, both of them were not obviously effected on them.

Abstract:C4-keto reduction in the TDP-daunosamine pathway of daunorubicin biosynthesis was catalyzed by DnmV ketoreductase. Epidaunorubicin producer has been constructed previously by disruption of dnmV gene and integration of aveBIV originated from biosynthesis pathway of avermectin. In this work, dnrIJ and dnmZU were amplified from genome of SIPI-DM, a high-daunorubicin producer. Recombinant plasmid pYG838 was constructed with aveBIV insertion between these two genes, which used as homologous recombinant arms. After screening and validation, an epidaunorubicin producer with dnmV replacing by aveBIV which is genetically and metabolically stable was obtained. The lack of antibiotic resistant marker in chromosome of this mutant will be helpful for further gene disruption.

Abstract:A high productive poly γ-glutamic acid (γ-PGA) strain PGA-N in a culture medium containing no L-glutamine was isolated from fermentation products. With the following identifications of colony morphology, physiological and biochemistry experiments, and genetics, the strain PGA-N was classified as a Bacillus licheniformis. According to the product environment, the base culture medium having no L-glutamine was simulated. In order to enhance the production of the strain PGA-N, the fermentation conditions, such as carbon source, nitrogen source, were optimized and the γ-glutamic acid production reached 5.16 g/L after getting the optimum formulation of this culture medium. PGA-N was mutagenized with combination of NTG and UV. A mutant PGA-N-C10 was screened which PGA production was increased from 5.16 g/L to 8.82 g/L. The study also investigated the effects of agitation speed on the cell biomass, γ-PGA production and the γ-PGA molecular weight. The γ-PGA yield of PGA-N-C10 was as high as 11.00 g/L when the agitation speed was 400 r/min.

Abstract:The optimized cultural medium of fermentation for Candida sp. mutant strain YQ5 to produce S-adenosylmethionine was studied. The results of single factor experiment showed that the most favorable pH value, carbon source, nitrogen source organic nutrient is 6.0, 8% sucrose, 1.5% tryptone and 2% yeast extract, respectively. As to inorganic salts, MgSO4·7H2O, CaCl2, FeSO4·7H2O, CoCl2, CuSO4·5H2O, H3BO3 could improve accumulation of the intercellular SAM. The ingredients of the culture medium are also optimized by the orthogonal experiment. Fermentation for 48 h under the optimal condition resulted in AdoMet production at 1740.0 mg/L.

Abstract:Twenty bifidobacterial strains were tested for adherence ability with cellular model systems in vitro. Strain A03 and I06 showed high adherence to the epithelial cells. The inhibitory effects of Strain A03 and I06 on enteropathogen Staphylococcus aureus and Escherichia coli were demonstrated by simultaneous incubation and antimicrobial testing. These antibacterial activities were mainly induced by organic acids produced by bifidobacteria. The release of LDH of Caco-2 cells which were differently treated with bifidobacteria and enteropathogen, suggested that the adherence of bifidobacteria were essentially different with those of enteropathogen, and the adhesion of strain A03 and I06 could prevent the harmful effect of S. aureus and E. coli on Caco-2 cells.

Abstract:To study the method of in vitro transcription and the infectivity of in vitro RNA transcripts of full-length cDNAs of dengue 2 viruse, thus to lay the foundation of constructing infectious dengue virus clone. The full-legnth cDNA of DEN2 NGC was amplified by long RT-PCR. With PCR products as templates, the in vitro RNA transcripts could be prepared by the SP6 RNA polymerase system. The transcripts were transfected into BHK-21 by electroporation and inoculated brain of suckling mice respectively. The effect of infectivity of the transcripts was observed. The specific sequences of DEN2 NGC strain were amplified through RT-PCR of total RNA extracted from brain of mice and infectious cells and the histopathologic changes of mice brain and cells were observed by electron microscope. The results indicated the specific fragment of the dengue virus could be amplified from infected mice brain and cells, and the virion could be observed. The in vitro RNA transcripts of full-length cDNAs of dengue virus were infectious. The dengue virus could be assembled by infecting brain of newborn mice and transfecting cell.

Abstract:60 Candida strains were analyzed with randomly amplified polymorphic DNA(RAPD) from HIV-infected patients’ oral cavity. The results showed that RAPD-PCR fingerprinting appeared from zero to five bands whose size rang from 300 bp to 2 kb with P2 primer, Candida albicans have three characteristic bands of 300 bp, 400 bp and 600 bp in size, non-Candida albicans have the similar bands. They can be classified five genetic clusters and 14 genotypes by Cluster Analysis, two Candida albicans(P385&P403) with fluorocytosine-resistance were classified into C1 genotype for “Squared Euclidean Distance” being 0.115, one Candida albicans(P321) and one Candida glabrata(P522) who were resistant against Amphotericin B were classified into D1 genotype for “Squared Euclidean Distance” being 0.221. So, an abundant genetic polymorphism appeared in Candida species related HIV, RAPD could be as a reference for genotype of Candida albicans; different Candida speices had some special bands, different Candida strains had similar bands in the same species; it is perhaps that some genotypes were relevant to drug resistance.

Abstract:To investigate the formation and effect of nitric oxide (NO) on oxidative injury and anti-virus in human lung epithelial cells (A549) infected with respiratory syncytial virus (RSV) in vitro. A549 cells infected with RSV treated or untreated with Aminoguanidine (AG), the specific inhibitor for inducible nitric oxide synthase, were used to collect cellular supernatants and do the experiments. At indicated time points, the concentrations of NO, hydroxy radical (OH·), superoxide anion (O2.—) and malondialdehyde (MDA) were measured according to the kit reference. The viral titers were evaluated by plaque forming unit (PFU) assay. We found that RSV infection could markedly up-regulate the levels of OH· and O2.— in A549 cellular supernatants since 4 hours after infection. Meanwhile, the levels of MDA increased obviously in a time-dependent manner. The changes of each index varied significantly compared with the control group. But the NO content in the cellular supernatants could significantly decrease when AG inhibitor was used, and the levels of OH·, O2.— and MDA were also decreased accordingly in comparison with the corresponding RSV-infected group. In addition, the titer of virus was increased, which was about 1.5 times as many the RSV group 24 h after RSV infection. The changes of these indices have significantly different compared with the corresponding RSV-infected group. In conclusion, RSV infection could induce high-level NO. The NO may associate with the content of free radical, which could decrease the viral titers in the infection, but lead oxidative injury to normal cells.

Abstract:Arbuscular mycorrhizal fungi(AMF) are ancient, asexual, and obligate symbiotic endophytes which have not been cultured in vitro. So there is some limitation in the study of mycorrhizology. While the molecular technology based on DNA analysis could increase the detection sensitivity and specificity of AMF. rDNA sequence homology and variability can reveal the relationship between species and their evolution. Thus rDNA sequence analysis are widely used in the classification, identification, genetic, ecology and biodiversity of AMF. This article summarizes the rDNA sequence analysis techniques and their application in phylogeny, molecular detection and community structure of AMF in different plant vegetation.

Abstract:Microbial lipase, one of important industrial biocatalysts, has been used widely in many industrial and agricultural fields. It is always the research focus to screen, mine and develop the microbial lipases with novel catalytic activity and high stability. This paper introduces briefly the pathways and methods to mine novel microbial lipase resources from six aspects, including extremophile, metagenome, genome database, protein engineering, immobilization, chemical modification, etc.

Abstract:To develop Students’ Practical Ability according to the teaching requirement and culture aim of preventive medicine major, the teaching plan, teaching content, teaching methods, and experimental checking methods were explored and the experimental teaching pattern of medical microbiology adapted to preventive medicine major was constructed. The investigation showed that the experimental teaching pattern helped to cultivate the students’ operating ability, thinking of scientific research and ability of aggregate and solving analysis. Moreover, it helped to develop the students’ co-operative consciousness and team spirit. It indicated that the new pattern was superior to the traditional experimental teaching.

Abstract:The teaching of the Fermentation Engineering Experiment in normal university must serve for the basic education, placing students’ creative spirit and practical ability in the first place. Therefore, teaching reform of the Fermentation Engineering Experiment under the background of new curriculum reform of basic education should be studied from the curriculum content, teaching methodology, training pattern and assessment system, in order to cultivate the normal-university students’ research ability, working attitude, creative and teaching ability.

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Abstract:The reform and practice on teaching approaches of microbiology integrated case-based study, heuristic teaching, interaction teaching, comparison expression teaching and inductive learning was explored, which was contraposed the education aims of independent college and student’s trait, and combined to the fact of University of Electronic Science and Technology of China Zhongshan Institute. The result of practice showed that student enthusiasm for study was mobilized, and better results in teaching were got by application of diversiform teaching approaches.

Abstract:Abundant humic acid present in compost hinder the metagenomic study of uncultured microorganisms in compost environment. We developed an effective method for isolating metagenomic DNA from compost samples. By combinations of Sephadex G200 + acid washed PVPP column and electroelution techniques, this method was effective in purifying of metagenomic DNA from compost samples. With this purified DNA, we succeeded in constructing a cosmid library containing about one hundred thousands clones. And a novel β-glucosidase gene was cloned and sequenced from this library. Targeting the problem of low frequency of positive clones in the library, we also studied the effects of different centrifugal speeds on the content of contaminated eukaryotic DNA in the isolated metagenomic DNA, in order to preclude the presence of eukaryotic DNA in metagenomic library.

Abstract:To set up a new method of detecting bacterial number in situ, NADH fluorescence method based on the fluorescent characteristic of NADH was used. When the concentration of NADH ranged from 10 nmol/L to 0.2 mmol/L, its concentration had a good line relationship to the fluorescence intensity(R2= 0.9905). Separating bacterial cells by centrifugation and extracting NADH with hot Tris-HCl buffer, the result of bacterial count detected with NADH standard plot was 1×104 CFU/mL in an hour. In summary, NADH fluorescence method is rapid, sensitive, simple and reliable to detect total bacterial number. Therefore, the method can be widely applied in the field of food sanitation and safety, environment detection and so on.