Abstract:

Abstract:NS2 is a nonstructural protein of Periplaneta fuliginosa densovirus (PfDNV) with a molecular mass of 30 kD, whose function is not yet clearly understood. In order to study the expression, subcellular distribution and the function of NS2 protein, the coding region of NS2 was amplified from the hindgut tissue of cockroaches infected with PfDNV by RT-PCR and then the recombinant prokaryotic expression vector pET28a-NS2 was constructed. The recombinant plasmid was transformed into E. coli BL21 (DE3) to express the 6×His fusion protein in the bacteria. After purification, the fusion protein was injected into New Zealand rabbits to prepare polyclonal antibody. The specificity of the anti-NS2 antibody was successfully proved by western blotting on the eukaryotic expressed products of NS2 protein．Meanwhile, the full sequence of ns2 gene was also cloned into the eukaryotic expression vector pAC. The recombinant plasmid pAC-NS2 was then transfected into Schneider line 2 (S2) cells to express NS2 protein in the insect cells. The subcellular localization of NS2 in the insect cells was then investigated by indirect immunofluorescence technique using the anti-NS2 polyclonal antiserum. The confocal laser scanning microscope observation showed that NS2 protein was located primarily in the cytoplasm with some punctate nuclear staining.

Abstract:This research adopted silt as the sample, and the five highest hydrogen production performing strains contained in the sample were isolated. The strain whose hydrogen production was the highest was identified as Enterobacter cloacae by the analysis of 16S rDNA sequencing and comparison. It is showed by Plackett-Burman Experimental Design that only glucose, citric buffer and reducing agent had significant effects on hydrogen production by Enterobacter cloacae FML-C1. The path of steepest ascent was undertaken to approach the optimal response region of those three factors. Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed to investigate the interaction of the variables and to ascertain the optimal values of the factors, which finally led to the maximum hydrogen production (VH2). The theoretical optimal medium conditions were: glucose 21.5 g/L, citric buffer 13.6 mL/L, reducing agent 10.0 mL/L. The five tentative tests matched this model well. The final VH2 was up to 2347.4 mL/L, which was 127.42% enhanced in comparison to the original. The result shows that PB experiment design and RSM analytical method work well in selecting factors which have significant influences on the hydrogen production and, moreover, achieve the ideal optimal result.

Abstract:In anaerobic bottles fermentation, glucose, fructose, xylose, lactose, maltose, sucrose and sugar alcohols could be used to produce succinic acid with Actinobacillus succinogenes. When sorbitol was utilized as the carbon source in the batch fermentation, more succinate and ethanol were produced compared with those using glucose, while producing less acetate and formate. The metabolic flux analysis results showed that the flux partitioning at PEP node was stable when glucose was replaced by sorbitol, but the flux partitioning at PYR and AcCoA nodes changed a lot because more reducing power (NADH) was generated to meet the more requirement the synthesis of succinate and ethanol.

Abstract:Effects of phosphate limitation on glycerol biosynthesis and intracellular phosphorus accumulation of Candida glycerinogenes were studied by recycling yeast cells. The results demonstrated that, throughout the fermentation of yeast cells recycled, intracellular phosphorus accumulation gradually decreased when yeast cells were re-inoculated from the suitable phosphate or rich phosphate medium to the low phosphate medium; while intracellular polyPhosphate accumulation rapidly increased after yeast cells were re-inoculated from the low phosphate medium to the suitable phosphate or rich phosphate medium. When yeast cells were re-inoculated from the suitable phosphate medium to the low phosphate medium at the fourteenth or thirty-eighth hour, glycerol yields on glucose of 60.9% or 61.4% could be achieved with a productivity of 2.03 g/(L·h) or 2.23 g/(L·h). These phenomena proved that it is necessary for glycerol overproduction by C. glycerinogenes to limit phosphorus concentration in fermentative medium, which provides an important basis for its glycerol production by repeated fed-batch fermentation.

Abstract:A new strain ZOYM was isolated from deep ocean of China and its 16S rRNA gene sequence showed high homology with that of the other published Planococcus species. Plasmids DNA were isolated and multiple bands were detected on an agarose gel, and two small of them, designated pPCZ1 and pPCZ2, were further cloned and sequenced. The complete nucleotide sequences of pPCZ1 and pPCZ2 consisted of 4738 and 7975 base pairs, encoding 3 and 8 proteins, respectively. The predicted replication proteins (Reps) of pPCZ1 and pPCZ2 showed high homology with that of Staphylococcus plasmid pSCFS1 and Bacillus plasmid pBM19, respectively. In additional, the Reps of pPCZ1 and pPCZ2 displayed homology with each other. No conserved dso and sso of the rolling-circle plasmids were found on pPCZ1 and pPCZ2, while multiple direct-repeats and AT-rich sequences were found on upstream of the rep genes, suggesting that replication of the two plasmids might be in a mechanism of theta-type. This is first report on the complete nucleotide sequences of Planococcus plasmids pPCZ1 and pPCZ2.

Abstract:To selectively isolate Microbispora sp. from mangrove, 23 rhizosphere soils of different mangrove plants were collected in Wenchang, Hainan, China. After pretreatments of dry heat (100°C 60 min or 120°C 60 min) and treatment with Chloramine-T (1%, 30 min at room temperature) for each sample, 100 μL of the 10-1~10-3 dilutions of the resultant suspensions were transferred and spread onto the selective isolation media. GA and HV media were employed as the isolation media that supplemented with 0.5 mg/L multi-vitamin, 50 mg/L~100 mg/L K2Cr2O7, 50 mg/L cycloheximide and 50 mg/L nystatin. One hundred and ninety nine actinomycetes including 147 Streptomyces-like isolates and 52 non-Streptomyces-like isolates were isolated according to their morphology on agar plates and under microscope. Seven Streptomyces-like isolates and 28 non-Streptomyces-like isolates were putatively identified to genus level based on 16S rRNA gene sequence analysis, which belong to Microbispora(19), Streptomyces(7), Nonomuraea(4), Micromonospora(2), Streptosporangium(1), Asanoa(1), and one uncertain genus under Micromonosporaceae. It is found that plenty of Microbispora spp. inhabit in mangrove rhizoshere soil.

Abstract:155 endophytic fungi were isolated from Equisetum arvense L., Impatiens chinensis L. and Myriophyllum verticillatum L. They were identified to 26 taxa. The antagonistic activities of these isolates against 6 isolates of plant pathogenic fungi were tested on the medium, and 37(23.9%) isolates were activitive against one or more phytopathogens. The percentage of antifungal active isolates from E. arvense L., I. chinensis L. and M. verticillatum L. were 13.9%, 29.2% and 37.1%, respectively. It was lower than that of terrestrial plants. The active isolates were mainly belonging to 5 genera including Cladosporium, Trichoderma and Geotrichum.

Abstract:In order to study the correlation between microbial diversity and the pollution degrees of the rural drinking water in Dongjiang River basin. Five types of drinking water of this basin were collected, and fifteen water samples of five types of drinking water of this basin had been collected from reservoir, centralized water supply wells, wells in the vicinity of pig farms, wells nearby embankment and wells in villages. The six (physical, chemical, and biological) property indices of water samples were tested, at the same time, the DGGE analysis was done. The results of PCR-DGGE fingerprint indicated that bacterial richness of these drinking water samples were high, and different samples in fingerprint were different distinctively. The UPGMA dendrogram of sample basis on DGGE fingerprints showed the structure of different types of bacteria in drinking water in rural communities is obvious differences. And the results of CCA showed that the concentration of phosphorous has the largest relevance to the community structure of bacteria in water samples, followed by the concentration of nitrogen in the water. Ten typical bands were excised and sequenced. The sequences obtained were affiliated with Spirochaetes, Cyanobacteria, Proteobacteria, Actinobacteria, Acidobacteria.

Abstract:A bacterial strain which could grow well on the substrate of PAEs as the sole source of carbon and energy was isolated from contaminated sludge in the river of WeiFang in ShangDong province and it was designated as JDC-3. Based on the morphology, biophysical and biochemical properties as well as molecular characteristics, this isolate was preliminarily identified as Delftia sp.. A fragment of phthalate dioxygenase gene was successfully amplified from the genus of Delftia for the first time using a set of degenerate primers. Meanwhile, the degradation capability of JDC-3 was determined by HPLC using DMP as test substrate. The results showed that the optimal pH and temperature were at 7.0~8.0 and 30°C~35°C respectively. The degradation kinetics of JDC-3 was studied in different initial DMP concentration under optimal conditions. The results indicated that the degradation dynamic equation was ln C = - 0.06837 t + A when DMP concentration was lower than 300 mg/L, with half life of 12.48 h. The degradation rate decreased and half life of JDC-3 prolonged as the initial concentration kept on increasing.

Abstract:Pollution of heavy metal chromium Cr(VI) in environment would cause cancer. Chromium Cr(VI) was defined as one of 129 important pollutants by American EPA. This study was carried out on the conditions of removal Cr(VI) including different originated pH, temperature, carbon source and the volume ratio of bacteria to wastewater using an acidproof Desulfovibrio (SRB7) which was departed from sewage sludge effluent water of a chemical plant. Meanwhile the characteristics of reducing Cr(VI) through sulfureted hydrogen approach, electron transfer approach and adsorption approach were studied. The results showed that the conditions of removal Cr(VI) were as follows: pH 7.5, temperature 36°C, using lactate sodium as the carbon sources and the volume ratio of bacteria to wastewater at 1:5(V/V), when the influent concentration was 50 mg/L. In this study for characteristics of reducing Cr(VI) by SRB7, adsorption approach couldn’t remove Cr(VI); electron transfer approach which removed 51.42% of the Cr(VI) at 24 h, was not preponderant in the process of reduce Cr(VI); sulfureted hydrogen approach which removed 78.02% of the Cr(VI) at 24 h, was preponderant in the process of reduce Cr(VI).

Abstract:One hundred and fifty two actinomycetes were isolated from forty two radiation-polluted soil samples, using six different isolation media. Sixty cultures were chosen for 16S rRNA gene sequence and systematic analysis, which based on their morphology and ARDRA. Results of 16S rRNA gene sequences blasting showed that the strains were assigned to 12 recognized genera of actinomycetes, most of them fall within Streptomyces genus and a great deal of strains belonged to rare actinomycetes, which indicated a rich diversity of actinomycetes in the radiation-polluted soil.

Abstract:A bacterium strain named GF31, which could use cypermethrin as the sole source of carbon, was isolated from a polluted soil. Through morphological observation, 16S rDNA genetical analysis, physiological and biochemical tests, the strain GF31 was identified as Pseudomonas aeruginosa. The optimal pH and inoculating quantity for the cypermethrin degradation were 7.0 and 10%, respectively. The degradation activity of strain GF31 could keep at a high level even when the cypermethrin concentration was increased to 300 mg/L. Furthermore, nitrogen sources were proved to be able to accelerate the degradation rate, especially the organic nitrogen sources. When 0.5 g/L peptone was added, the average degrading rate of 100 mg/L was 13.64 mg/(L·d), which was two times as that of the ammonium sulfate. It was preliminarily speculated that the degraded products and the alkaline environment might inhibit the growth and activity of strain GF31.

Abstract:Glucose was transported by the large number of hexose transporters in yeast cells. There were 18 hexose transporter genes had been identified in Saccharomyces cerevisiae. However, as an excellent expression system, there was no information of these genes had been reported in Pichia pastoris. Based on high homologous recombination efficiency in yeast, we chose G418 resistance for screening, 200 bp were cloned from the up and down sequences of HXT1 ORF respectively, then ligated to the 5￠ and 3￠ end of G418 resistance gene for recombination. After electroporation of GS115 spheroplast and screened through different G418 concentration plates, finally we obtained one HXT1 gene deletion mutant named GS115ΔHXT1. The growth rate and glucose consumption of this mutant were both lower than the wide type.

Abstract:The study provide a theoretical basis for the industrial production of a elastase-high-yield strain which was isolated from the straw, and the selected strain was identified. The screening strategy included casein (skim milk) plate selecting and elastin (beef tendon) re-screening. And then, the morphological, physiological and biochemical characteristics as well as 16S rRNA sequence homology of the selected strain were studied. Finally, the strain LSF-97 which had a excellent decomposing ability to beef tendon was obtained. The results showed that the strain LSF-97 is relative to the Bacillus pumilus with 100 % similar in sequence under the phylogenetic tree, the morphological and physiological and biochemical characteristics are also consistent with pattern of bacteria. So it was identified as Bacillus pumilus.

Abstract:Two antagonistic strains of Bacillus, 19E2 and 13A1, were isolated from soil and were shown to have strong inhibitory effects on the growth of Colletotrichum higginsianum. Through morphological observation, physiological and biochemical characteristics, analysis of 16S rRNA gene sequence, and partial analysis of specific chromosomal genes, the two isolates were both identified as Bacillus amyloliquefaciens. Growth of C. higginsianum on potato dextrose agar was inhibited by strains 19E2 and 13A1 by 75.62% and 85.35% respectively at 10% concentration of the Bacillus culture. Growth of C. higginsianum was completely inhibited (100%) at 20% Bacillus culture concentration. Results also demonstrated similar inhibitory effects by the two Bacillus strains on growing cultures of C. capsici, C. gloeosporioides, Botrytis cinerea, Cylindrocladium spathiphylli and Fusarium oxysorum.

Abstract:Using the Gram-positive Staphylococcus aureus as the indictor bacterium, fourteen antibacterial strains were initially obtained by the bilayer-media screening method from the raw milk samples, and one isolate was found to exhibit the higher antibacterial activity against the indicator. This isolate was further studied on its individual and cultural morphology features, partial physiological and biochemical reaction activities, G+C content, the sequence features of the 16S rDNA and the species-specific N-acetylmuraminidase gene (acmA), consequently, it was identified as the Lactococcus lactis subsp. lactis strain, named as MB191. An evaluation of the antimicrobial spectra of MB191 was subsequently performed, it showed the remarkable activities against not only the tested Gram-positive bacteria, but also several Gram-negative bacteria including Pseudomonas syringae and P. fluorescens, as well as the yeast Debaryomyces hansenii, which was a distinctive feature that was not reported prior to this study.

Abstract:PCR-SSCP (single-strand conformation polymorphism) was used for studying the community changes of pronucleus microorganisms in various fermenting stages of Luzhou-flavor Daqu. The results showed: (1) The pronucleus microorganism’s community was similar and also had the polymorphism in each simple of various fermentation stage; (2) Different microflora had complex ecology effects of coordination and the restriction; (3) The diversity indexes of different stage of Daqu microorganisms were around 1.69~2.01, and the composition of them was stable relatively; (4) The similarity indexes were 0.67~1.00, and much higher in the approaching stages.

Abstract:Klebsiella oxytoca M5al was used as the original strain to breed mutants after mutagenesis with NTG, 44 single colony were obtained from medium containing 0.17 mol/L NaBr-NaBrO3 (proton suicide method) and 3 lactic acid-producing mutants were selected by shaking cultivation in optimized medium, their lactate dehydrogenase activity was only 50.6%、58.8%、61.3% of the parent strain, respectively. The lowest one of them batch-cultured in 5 L fermenter, results indicated that the yield of lactic acid of the mutant was decreased remarkably, reversely, acetic acid and 1,3-propanediol were increased observably.

Abstract:Quorum sensing systems of pathogens are central regulators for the expression of virulence factors. Increasing evidence implies that targeting the quorum sensing system of many pathogenic bacteria is a promising therapeutic approach to control infections. In this work, we isolated 47 strains of actinomycetes from the mud sample of Jiaozhou Bay. Quorum sensing inhibitory activity was monitored by Chromobacterium violaceum CV026. As a result, the culture broth extract of actinomycetes WA-7 was found to have significant quorum sensing inhibitory activity. This strain was assigned to the genus Streptomyces based on its 16S rDNA sequence. Further investigation revealed that the extract could inhibit the quorum sensing-controlled violacein and proteases production of C. violaceum in a concentration-dependent manner.

Abstract:We analyzed the genotype of 120 Cryptococcus neoformans and 9 Cryptococcus gattii strains isolated from cryptococcosis patients residing in 16 provinces of mainland China, using methods of DNA fingerprint, IGS sequence, MLST and construction of dendrogram based on M13 fingerprint. 120 serotype A strains exhibited an identical M13-based VNI subtype, which was distinguishable from the reference VNI molecular type, MLST also showed the same result, for convenience we named this unique genotype VNIc. (GACA)4 and URA-RFLP could not separate VNIc from other subtype of VNI. The 9 serotype B strains of C. gattii portrayed a typical VGI molecular type. This research showed that VNIc is responsible for the majority of clinical cryptococcosis in China.

Abstract:One virus strain was isolated from the nasal secretion of a bovine suspected to be respiratory tract disease at a beef farm in Heilongjiang province. The virus could grow well and produce typical cytopathic effect in MDBK cells. Bovine parainfluenza virus type3(BPIV3) has been identified by a series of systematic identification such as physicochemical features, RT-PCR, and sequence analysis. As a result, the virus is an RNA virus, which is of hemagglutination and is very sensitive to ether and chloroform, no resistance to heat and acid. The homology of the nucleocapsid(N) gene sequence of the isolate and of GenBank is 82.6% to 99.1%. The isolated virus was confirmed as Bovine parainfluenza virus type3 named BPIV3 DQ1 strain. Specific primers were designed and synthesized according to the reported N protein gene sequence of Bovine parainfluenza virus type3 in GenBank. The size of 704 bp fragment was amplified and 10 TCID50/100 μL of viral nucleic acid was detected.

Abstract:Acetic acid bacteria are Gram-negative, obligate aerobic bacteria that have the ability to incompletely oxidize alcohols or sugars to organic acids as end products. The taxonomy of acetic acid bacteria has undergone many changes in the last 30 years. The early classification systems for these bacteria were based on morphological and biochemical characteristics. Today, the acetic acid bacteria are classified as the consensus result of a polyphasic analysis, combining phenotypic, chemotaxonomic and genotypic data. This paper reviewed the polyphasic taxonomy of acetic acid bacteria, mainly introduced the current classification of acetic acid bacteria, then discussed the application of phenotypic, chemotaxonomic and genotypic method in the taxonomy of acetic acid bacteria.

Abstract:With the development of the food industry in China, it has been found that food safety is becoming the biggest issue in the food manufacture and logistics. Accurate and timely to establish a risk assessment method in produce market is the challenge for food safety system. Predictive microbiology is a core early warning technology in the food safety risk assessment. According to the microorganism predicting model, the pathogen and spoilage microorganism’s growth in food can be fast judgment in advance. And it plays an important part in controlling the growth of pathogen and the spoilage microorganism in food. This paper summarized the predictive microbiology model’s establishment and the present research situation, and discussed the present situation and application of predictive microbiology in food safety risk assessment. The future trend of predictive microbiology in food safety risk assessment was prospected as well.

Abstract:Electricigens play an important role in microbial fuel cell (MFC). This review provides an introduction of different electricigens on theirs taxonomical group, biochemical, physiological and morphological characteristics. The ability of electricity production of electricigens and electron transfer mechanisms in microbial fuel cells are also concluded. The prospect of waste water treatment and bio-electricity production is underlined, it is point out in this review that the future research of microorganism for MFC should be focused on enrichment, adaptation, modification and optimization by multi-strains application to improve the performances of MFC.

Abstract:Triphenylmethane dyes are widely used in textile dyeing, medicine, biological staining, paper, leather, food and cosmetic industries. Their special stable chemical structures make them difficult to be degradated and decolorized. The biodecolorization research of triphenylmethane dyes will provide the fundamental knowledge for the treatment of dye-containing wastewater and bioremediation of dye-contaminated environment. In this paper, the recent research progress in biodegradation and decolorization of triphenylmethane dyes by microorganisms, such as bacteria, actinomycetes, fungi and alga, as well as the functioning enzymes and their coding genes, were reviewed. The decolorization mechanisms and degradation pathways of triphenylmethane dyes were discussed based on the decolorizing intermediate products of different microbes. The development and application of triphenylmethane dyes biodecolorization and biodegradation were also prospected.

Abstract:Pseudomonas aeruginosa is one of the most common causes of nosocomial infection due to its intrinsic resistance to antibiotics. In the host, glutathione (GSH), one of the most important intracellular antioxidants, provides protection against high levels of oxidative stress. A decrease in GSH levels in tissues infected with P. aeruginosa has been observed while interactions between pyocyanin and GSH maybe partially attribute to P. aeruginosa infection. In this review, the relationship between GSH and the pathogenicity of P. aeruginosa has been discussed based on the author’s own research results and the latest literature.

Abstract:Cordyceps militaris is of significant economic value in medical care and food exploitation because of its many physiological activities. This paper reviews (1) the taxonomic position of its anamorph, (2) interesting culture ways, (3) strain degeneration and genetic variability, and (4) research progress in bioactive compounds and pharmacological functions.

Abstract:A new teaching model for food fermentation technology education is proposed in this paper, aiming at improving some of the drawbacks of the traditional teaching method. Some novel approaches, such as summarization, comparison, discussion, as well as bi-lingual lecturing and multi-media assisted teaching, are introduced to inspire students’ passion for learning. Meanwhile, arranging students as dedicated class speaker and organizing students to participate in the exploring experiments also reflect the technology major education characteristics of normal university.

Abstract:“Three-multi” overall evaluation system on the teaching effect of Microbiology experiment, which consisted of multi-aspect, multi-angle and multi-level, was discussed in this paper. The evaluation system showed a remarkable effect in stimulating the leaning interests of students especially.

Abstract:Bacillus megaterium strains are commonly used in microbial fertilizer (MF). MF products are often contaminated by other B. cereus group members, which have similar phenotype such as Bacillus cereus, B. thuringiensis, B. mycoide. For quality control and safety of MF, a rapid and accurate method is needed to distinguish the strains of Bacillus megaterium from B. cereus group. Based on specific nucleotide sequences of the spoOA genes, 2 pairs of species-specific primers were designed and a multiplex-PCR (mPCR) was developed for this purpose. When the optimized mPCR was used to detect the DNAs of 24 reference strains from three genera of Bacillus, Paenibacillus, and Brevibacillus, all B. megaterium strains showed single fragment of 443 bp and Bacillus cereus group showed a fragment of 411 bp. However, no any amplified product was from the other bacteria. The sensitivity of mPCR was 105 CFU/mL. The mPCR results of 10 isolates of B. megaterium/B. cereus group and 8 products of MF coincided with the biochemical assay. Taken together, our newly developed mPCR assay was species-specific and effective in application. It can be used to detect and identify the strains of B. megaterium and B. cereus group from microbial fertilizer products.