Abstract:PAHs是石油中芳香族化合物的主要成分, 是一类可持久性污染环境的有机物, 具有很强的致癌、致畸、致突变效应^[1]; 同时石油污染又常常伴随着盐碱化环境存在, 如我国胜利油田、大港油田、大庆油田等陆上油田就位于盐碱化土壤环境中; 而石油运输过程中泄漏及事故也会使近海的盐碱滩受到污染, 如墨西哥湾的漏油事件和大连输油管道破裂就造成了周围海域沿岸盐碱土壤的大面积污染。由于PAHs可通过生物累积及食物链的传递, 给生态环境和人体健康造成极大危害, 因此受到广泛关注^[2?3]。
微生物降解被公认是去除环境中PAHs的重要途径之一, 但在盐碱环境中多环芳烃微生物修复的研究还鲜有报道, 因此筛选能够在高盐碱条件下降解PAHs的微生物, 具有重要的现实意义。本期介绍了宋立超、张玉龙等发表的论文“盐碱土壤PAHs降解菌的筛选鉴定及其降解特性”^[4], 作者采用富集培养的方法, 从天津大港油田PAHs污染盐碱化土壤中分离出一株能以菲、芘为唯一碳源和能源的团泛菌(Pantoea agglomerans)TJB5, 研究了该菌株降解菲、芘效果的条件, 发现该菌对菲、芘具有良好的降解效果。这是首例团泛菌降解PAHs的报道, 为在盐碱和PAHs双重胁迫下微生物修复的研究提供了一个很好的材料。
虽然目前的结果仅限于菌株筛选及其降解PAHs 的特性研究, 但相信随着研究工作的开展, 通过对该菌在盐碱环境中降解PAHs 类污染物机制的深入研究, 将为盐碱环境中多环芳烃污染的微生物修复提供科学依据和微生物资源。

Abstract:A predominant PAHs-degrading strain TJB5 was isolated from PAHs-contaminated salt-alkaline soil in Dagang Oilfield of Tianjin, which can use phenanthrene and pyrene as sole carbon source for growth in the selective culture medium. Strain TJB5 was identified as Pantoea agglomerans according to the results of morphology and the phyogenetical analyses of 16S rDNA sequence. The effect of initial concentration of phenanthrene and pyrene, inoculating pH and salinity on degradation efficiencies was investigated. The optimal degradations were determined. The results indicated that the degrading characteristics of the strain were fine. More than 93.3% of phenanthrene and 20% of pyrene in the medium were degraded in the liquid medium with 50 mg/L phenanthrene and pyrene, pH 6.8?9.5 and salinity ranging from 2% to 3% after 15 days at 30 °C.

Abstract:近年来, 水源性病毒疾病的爆发在世界范围内被大量报道, 大量研究证实^[1], 外环境水体及淤泥是病毒存活循环的主要场所, 并因此频频引发传染病的流行。但在生活环境的各种水体中, 除生活污水外, 其所含有的病毒浓度往往很低, 以目前现有的检测方法, 仍然达不到不经浓缩而直接从水中检测病毒的目的。同时,食源性病毒的感染剂量非常低, 10?100 个病毒粒子即可引发感染。病毒在离体条件下存活力很强, 对各种理化因子有较强的抵抗力, 耐乙醚和弱酸, 用氯仿、反复冻融、超声波处理都不能使其失活。因此, 水环境中微量存在的病毒仍然对人类的健康带来很大的威胁。
在我国, 虽然已经建立起了以PCR 为主导的病毒快速检测方法, 但是对于水样本的前处理技术至今没有找到十分理想的病毒浓缩方法, 无法有效去除样本中的抑制物, 这些因素都严重制约了针对水中食源性病毒的检测和预防。要掌握各种水体中病毒污染的基本状况, 样品中病毒的浓缩是能否得以成功检测的关键。另外, 目前世界上绝大多数国家所执行的标准中, 对病毒的检测标准及其指示生物都没有做出明确说明,归根结底的原因是由于至今没有建立起有效的方法。
有鉴于此, 针对水中病毒研究的热点和存在问题, 本刊2009 年第1 期发表了寇晓霞、吴清平等^[2]针对自来水和污水两种不同水体中病毒的浓缩方法。在现有的检测和浓缩方法的基础上, 通过不断创新, 解决现有方法中存在的主要问题, 摸索制约水体中病毒浓缩方法的关键点, 评价不同方法的优劣和实用性。三氯化铝沉淀法最大的优点是可适用于绝大多数具有不同水质特性的水样, 特别是可以克服膜过滤法因易堵塞而对水体悬浮物浓度有严格限制的缺陷。另外, 就检测条件而言, 该方法无需过滤装置等, 也省去进口的阳电滤膜, 从应用推广的角度更为方便, 费用成本低, 对于系统研究我国水中常见食源性病毒检测和监测有一定的应用价值。
目前, 该课题组对水体中病毒浓缩方法进行了多方面的应用。对广州河涌水的病毒污染情况进行了调研,初步了解和掌握了病毒的污染状况。广州市河涌水中食源性病毒污染的总阳性率为37.8％。其中有7 个点呈诺如病毒阳性, 8 个点呈轮状病毒阳性。文献[3?4]报道此类病毒的流行月份、季节性与环境水中调查的病毒污染情况基本吻合, 说明了临床发病与环境中此类病毒的污染有一定的相关性。另外还有些点呈甲肝病毒阳性和星状病毒阳性。调研结果表明三氯化铝沉淀法浓缩水体中病毒的方法具有实用性。

Abstract:The bacterium isolated from a water sample of Yunnan tengchong hot spring can secrete a kind of thermophilic xylanase. It was identified and named as Geobacillus sp. PZH1 by morphologic observation, physio-biochemical characteristics and 16S rDNA sequence alignment. Subsequently, its secreted xylanase and the xylanase’s characteristics were researched preliminarily. SDS-PAGE electrophoresis and zymogram analysis suggested that the xylanase’s molecular mass was 69 kD; the optimum pH and temperature of the partially purified enzyme were 7.0 and 70 °C respectively, and it performed noted activities from pH 5.0 to pH 11.0 and from 40 °C to 100 °C; it had high stability from pH 5.0 to pH 12.0 and under 70 °C; from 40 °C to 100 °C, no cellulase activity was detected for the partially purified xylanase.

Abstract:A protease producing spore-forming strain named HFBL0079 was islated from soil by measuring clearing zone in alkaline casein plate. Bacillus sp. HFBL0079 was identified as B. amyloliquefaciens by phenotypic properties and 16S rDNA sequence. Its optimal growth temperature was 35 °C?37 °C and initial pH was 8.0. Protease activity increased quickly in log phase in accord with biomass and was steady in stationary phase, the maximal value was found in 16 hour. The highest protease activity was found when nitrogen source was soy protein isolate. The protease was alkaline protease because the highest activity was shown in pH 10. The alkaline protease was shown activity to multi substrate, the highest hydrolysis degree was found in collagen (42.3%) more than casein, oval bumin, BSA, and the hydrolysis degree of keratin was 15.3%, these results indicated the alkaline protease had some novel properties.

Abstract:A novel γ-polyglutamic acid (γ-PGA) producing-strain Bacillus subtilis PGS-1 was isolated from soil, which could produced a large mount of γ-PGA in the medium containing glucose and glutamate. The highest yield 26 g/L of γ-PGA was obtained in flask culture. Compared with other reported γ-PGA producing-strain, γ-PGA derived from Bacillus subtilis PGS-1 had a lower molecular weight (3×10⁵?4×10⁵ kD) and a narrower polydispersity (1.3?2.0), which could endow γ-PGA a promising application, such as in the drug delivery system.

Abstract:A strain SWD-28 producing cold-active endoglucanase was isolated from samples of Changhai county in Yellow Sea. It was identified as Penicillium cordubense based on the morphological and ITS sequence. An endoglucanase was isolated and purified from it. The specific activity of endoglucanase was 26.4 U/mg increased 20.6 fold and coefficient of recovery was 13.1%, the molecular mass was 33.1 kD. Analysis by circular dichroism (CD) spectrum of purified endoglucanase protein revealed that it displayed typical α-helix structure and α-helix 49.9%, β-sheet 0.0%, turn 24.3% and random coil 25.8%. Enzymatic properties showed that the optimum pH value is 5.0 and the optimum reaction temperature is 35 °C, at 5 °C the relative enzyme activity still reach to 60%.

Abstract:The polysaccharide from oceanic red yeast were purified using chemical extraction method. The classical Sevag mothed was carried out in order to deprotein and the pure sugar was obtained through multi stage precipitation. The content of glucose was determined by sulfuric acid anthrone method, and the content of protein was analysis by coomassie brilliant blue staining. After artificial infection by the quantitative polysaccharide of oceanic red yeast, the activities of the immunological activite enzymes in the serum of the Charybdis Japonica were measured periodically. Meanwhile, infection by the equivalent normal saline was served as control. Experiment show: The purified polysaccharide was proteoglycan. Including 3.6% of glucose and 1.9% of protein. It also contained many kinds of amino acids and the content of aspartate was the highest. After artificial infection, Total SOD (T-SOD) in the serum of the Charybdis japonica had maximum enzyme activity in 12 hours and acid phosphatases (ACP) in 24 hours, alkaline phosphatase (AKP) in 48 hours, catalase (CAT) in 48 hours, lysozyme (LZM) in 12 hours. The highest point was higher than those in the control group (24%, 43%, 25%, 35%, 95%). And the enzyme activities recovered to the corresponding control levels. Conclusion: The activities of the immunity active factors in the serum of the Charybdis Japonica have different degrees of the enhancement in 48 hours after infected with the polysaccharide of oceanic red yeast. The polysaccharide has stronger immune stimulation.

Abstract:A hydrogen-producing acetogen strain ZR-1 was isolated from organic wastewater sludge by applying modified Hungate anaerobic method. According to morphological observation, physiologicalbiochemical characteristics and homology analysis of 16S rRNA gene sequence, the strain was identified as a genus of Clostridium glycolicum. The effects of temperature, pH, optimum substrate and metal ions on its productivity of acetic acid in anaerobic conditions were investigated and then optimized by uniform tests. The results indicated that the optimun temperature and initial pH of culture media for strain ZR-1 were 37 °C, 8.5, and it′s optimum substrate was butyrate. Supply of Mn²⁺ in culture medium can promote acetic acid production of ZR-1. At optimum cultivation conditions, the conversion rate of butyrate reached 12.7% and the content of H₂ was up to 28.73%.

Abstract:Not all of Aeromonas species were pathogenic, and some bacteria of this genus were found to have important utilization value in recent years. Effective utilization of discarded feather by microorganism-decomposing method could meet the requirements of environment and Low-carbon economy. However, screening and evaluation of more microbe resources should be favourable for solving the thorny problem on poor efficiency and low speed of biodegradation. In the study, keratinase-producing strains were isolated from decaying feather using feather selective medium, casein plate and enzyme activity assay of keratinase in fermentation liquid of feather. The morphological observation of cell and colony, sugar fermentation experiments, Gram stain, PCR and sequence analysis of 16S rDNA were performed for taxonomic classification. The strain named FD41 with the highest relative keratinase activity (RKA, viz. the ratio of keratinase activity unit to A₆₀₀ value of feather fermentation liquid) of 3.864 U/OD₆₀₀ was isolated. The BLAST using the 16S rDNA sequence (GenBank accession No. HM587254) of FD41 showed that the first 100 sequences, all from Aeromonas, shared high homology to HM587254 with 99% identity. According to the results of taxonomic classification, the strain FD41 was identified as an Aeromonas bacterium. This is the first report on keratinase-producing strain of Aeromonas bacterium. The measurement values of keratinase activity of fermentation liquid were found to be influenced signally by cell proliferation. The different strains and inoculation amounts resulted in very distinct proliferation curves of bacterium in liquid medium. These results suggested that the RKA was appropriate index and equalizing inoculation amount was prerequisite for screening and identifying of strains with high enzyme activity at same condition of liquid culture.

Abstract:A technology sigle-strand conformation polymorphism (SSCP) and a target 16S rDNA gene on V3 region were used to analyze mud volcano microbial community and structure. After extracting DNA samples from different mud deepth and month, get a 236 bp fragment by PCR. The fragment was used to analyze the microorganisms seasonal diversity of mud volcano by SSCP, and some target fragments were analyzed clone. Resluts showed: the bacteria polymorphism in Xinjiang mud volcano soil is significant, which is vulnerable to ecological and climatics factors. Pseudomonas is a dominant microorganism in Xinjiang mud volcano, it distributes widely in mud volcano and was affected little by ecological and climatics.

Abstract:Strain DB09208, an endophytic bacterium exhibited strong inhibitory activity in vitro against Fusarium oxysporum f. sp. cubense FS-0704 (race 4: FOC4) was isolated from Musa AAA, cv. Baxi grown in Hainan. Based on the morphological, physiological and biochemical properties, and the 16S rDNA sequence analysis, this strain was identified as Paenibacillus sp.. The strain DB09208 obviously inhibited the mycelial growth of FS-0704, with an inhibitory rate of 74.09%, pot experiments indicated the strain suppressed Fusarium wilt of bananas, the control efficiency reached 65.2%. It could significantly promoted the generation of roots with the effect was similar to that of IAA. These demonstrated that strain DB09208 should be useful in biological control bananas Fusarium wilt.

Abstract:Four thermophilic fungal strains producing cellulase (50 °C) were isolated from the compost of cotton residue in Xinjiang, having the ability of acid-resistant (the optimal pH is 4.5) and temperature-resistant (the highest temperature is 60 °C). The enzyme activities were measured using multiple substrates, such as sodium carboxy methyl cellulose (CMC-Na), microcrystalline cellulose, cotton, filter paper, starch and pectin. The highest filter paper enzyme activity (FPA) is 2.63 U/mL, the amylase activity is 6.17 U/mL and the pectinase activity is 5.86 U/mL. It was showed that these fungal strains and their secreted enzymes have great potential on cellulolytic biomass (cotton residue) degradation and utilization.

Abstract:The objective of this study was to screen and identify antagonistic bacteria against Ralstonia solanacearum from tomato rhizosphere soil. Four strains (YB1, YB6, YB22, YB70) showed strong antagonistic activity, with diameters of inhibition zone above 9 mm. The strain YB6, identified as Arthrobacter sp. according to its morphological, physiological and biochemical characteristics, presented the best and most stable effect against R. solanacearum. The fermentation conditions of the strain YB6 were 30 °C, pH 9.0, inoculum 3%, shaking at 100 r/min, sucrose as carbon source, and yeast condensate as nitrogen source. Under the optimized fermentation conditions, diameters of inhibition zone produced by the strain YB6 against R. solanacearum strains SST-Y and G2M1.70 increased by 76.72% and 81.14%, respectively.

Abstract:Glycosyltransferases play central roles in the glycosylation of biosynthetic pathways of many antibiotics. The prokaryotic expression and enzymatic features of Med-ORF8, a glycosyltransferase involved in the biosynthesis of medermycin with strong antitumor activity, still remains obscure. Here, firstly, we performed the computer modeling of the 3-D structure of Med-ORF8 to prove that the presence of 6*His-tag at the terminals of Med-ORF8 had no effect on its 3-D structure. Subsequently, we established two prokaryotic expression systems with pET vectors to express Med-ORF8, and found that pET-28a (+) could gain a higher yield of the target protein than pET-23a (+), but mostly in an insoluble form. Finally, we introduced a molecular chaperone gene into the system with pET-28a (+) and found that the co-expression of the molecular chaperone with Med-ORF8 could efficiently decrease the formation of the inclusion body and increase the accumulation of soluble Med-ORF8.

Abstract:A red pigment producing bacterium strain FS14 was isolated from the stem of the diseased Atractylodes macrocephala Koidz. The strain was classified into Serratia according to its morphology, the physiological and biochemical features and 16S rDNA sequence. Different from the other reported Serratia species, the F14S strain could secret the thermostable DNase and protease. These secreted thermostable enzymes were still active even after pretreated at 100 °C for 30 min, while less activity was found after pretreated at 60 °C?70 °C for 30 min. The reason for this phenomenon need to be further investigated.

Abstract:To further study physiological-biochemical mechanism of symbiote in imidacloprid-resistant brown planthopper (Nilaparvata lugens), imidacloprid-resistant strain of symbiote, Candida lipolytica, was domesticated with different concentrations of imidacloprid based on effect of insecticides on growth and development of C. lipolytica. The results indicated that after in vitro C. lipolytica, on solid culture medium containing 2 000, 1 000 and 500 mg/L imidacloprid were subcultured for continuous 20 generations, the colony numbers of C. lipolytica on solid culture medium containing 2 000 mg/L imidacloprid were no significant difference with those on control medium containing non-imidacloprid. When numbers of colony kept stable for continuous three generations, the domesticated strain was called 2 000 mg/L imidacloprid- resistant one. Morphological changes of imidacloprid -resistant and -susceptible strains pseudohyphae were further observed using light microscope, it was found that pseudohyphae of imidacloprid- resistant strain occurred malformation and become shorter, some appeared enlargement.

Abstract:Apoptosis is an important type of programmed cell death, which is necessary for the development and growth of higher eukaryotes including bacteria, yeast and filamentous fungi. It has been found that the apoptotic mechanism in filamentous fungi is more complex compared to yeast as they contain several homologs of the mammalian apoptosis-regulated proteins which are not present in the yeast genome. Apoptosis plays important roles in the development, reproduction and aging of filamentous fungi. Today, as new model organisms for apoptotic research, the filamentous fungi have been widely studied. In this paper we reviewed the phenomena, detection methods, functions and induction mechanisms of apoptosis in filamentous fungi.

Abstract:The undertaking of Biochemistry courses teaching is a process integrating fundamental knowledge informing and, more importantly, students’ comprehensive capabilities cultivating. The paper focused on the feasibility evaluation and reforming models in the innovation of teaching notions and cultivation of capabilities, and proposed effective measures on regenerating education concept and nurturing scientific and innovative ideas of the students, and enhancing the capacities on active learning, problem exploring, analyzing and solving of the students, as well as the soul communication between teachers and students, then aimed at improving the students’ learning interest, motivating their activity, initiatives and creativity, thus promoting the teaching quality and nurturing high-level specialized talents.

Abstract:Based on the experience of teaching the course Principles of Fermentation Technology, the study investigated the implication, procedure, and effect of learning outcome using case study and question method. The results indicated that the employment of case study method based on the procedure of selection, evaluation, discussion, and question method could strengthen the learning outcome and the mastery of knowledge. The method also contributed to linking theory with realities, inspiring the motivation of self-learning, and interest in study of the students, therefore, the effect of classroom teaching was elevated.

Abstract:In this communication, it was discussed how to nurture undergraduate students’ entrepreneurial abilities during engineering microbiology teaching. Through the reform of examination methods, students were guided to design and write feasible reports for microbiological products to simulate entrepreneurship; the advanced researches in microbiology were introduced to cultivate students’ creation and innovation abilities; the national standard was taught to enhance their law consciousness and improve their insight on market; the economic cost was calculated to improve their financial management skill. This innovated teaching method would stimulate students’ enthusiasm for entrepreneurship and also cultivate their innovation and entrepreneurial abilities.

Abstract:Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Pseudomonas solanacearum, Pseudomonas aeruginosa and Bacillus thuringiensis were used as indicator strains respectively, four antibacterial strains, named as 97, Z11, Z18 and Z19 were screened from 580 strains of bacteria isolated from Antarctic by the method of agar diffusion. The growth curves, antibacterial curves and phylogenetic analysis of 4 antimicrobial strains were studied. The results showed that all of the four strains reached the log phase when they were cultured 24 h, strain 97 was in the log phase when it was cultured after 48 h, and the remaining three strains Z11, Z18 and Z19, were in the stationary when they were cultured after 60 h. They had the highest antibacterial activity when it was cultured after 84, 96, 72 and 72 h, respectively. Phylogenetic analysis indicated that these four strains belong to genera of Rheinheimera, Psychrobacter, Pseudomonas and Psychrobacter, respectively.

Abstract:The aim of this study was to optimize a proper method to extract intracellular and extracellular protein from Saccharomyces cerevisiae to construct the proteomic maps. Methods of protein extraction and cultivation condition were optimized. The cells were cultured in YNB medium for 20 h and cells were separated by centrifugation. The extracellular proteins in supernatants were obtained through ultra filtration-freeze drying. Cell pellets were resuspended in SDS lysis buffer. The cell suspension were boiled for 5 min, after solubilized by sonication and stored until use. The intra- or extracellular protein from S. cerevisiae were separated by 2-DE and stained with silver nitrate. The separated protein spots in gels were analyzed by PDQuest. The results showed that over 200 spots of extracellular proteins and about 500 spots of intracellular proteins had been separated by 2-DE.

Abstract:The rhizosphere bacterium Pseudomonas sp. M18 can simultaneously produce two antibiotics: phenazine-1- carboxylic acid (PCA) and pyoluteorin. ppGpp, which is synthesized by RelA, can mediate bacterial stringent response to nutritional starvation. The relA gene was PCR amplified from the M18 strain chromosomal DNA template. The relA mutant of M18 strain (M18RAG) was constructed through inserted inactivation of gentamicin resistance cassette and homologous recombination. PCA production was assayed in PPM media. It was showed that the relA mutation resulted in a significant enhancement of PCA production. PCA production of M18RAG was about 1.5 to 2 times as much as that of the wild-type strain. The negative regulation of RelA on PCA biosynthesis and its gene expression was further confirmed by the trans complementation test of relA gene and the expression analysis of phzA'-'lacZ translational fusion.