水稻根面争论产碱菌1AG4的分离、鉴定及其固氮和对病原菌的拮抗作用

从水稻(Oryza sativa L.)越光根面分离到一株固氮菌株 1AG4,经生理生化特性鉴定,归类为争论产碱菌(Alcaligenes paradoxus)。1AG4 的固氮酶乙炔还原活性(ARA)为13.06 C2 H4 nm ol/m l·h,固定15N2 活性(N2 FA)为 2.052 15N a.e.% ,表明 1AG4 具有较强的固氮能力。平皿拮抗试验证明 1AG4可拮抗包括水稻三大病害病原菌在内的 14 种植物病原菌(Xanthom onas oryzae pv. oryzae ZHE173、Thanatephorus cucum eris、Piricularia oryzae Cavara、Alternaria longipes(Ellis etEverhart) Tisdale etW adkins、Cochliobolus sativus、Colletotrichum agaves Cavara、Colletotrichum lagenarium (Passerini)Ellis et Halsted、Colletotrichum panacicola Uyeda et Takim oto、Fusarium oxysp orum f. niveum 、Helm inthosporium turcicum Passerini、Phytophthora parasitica Destur、Verticillium albo-atrum Reinkeet Berthold、Phytophthora m elonis Katsura、Pseudom onas solanacearum Sm ith)的生长     

机油降解菌的筛选及其特性研究

从福州祥坂污水处理厂的活性污泥中分离到12株机油降解菌,经复筛得到1株具有较强降解能力的菌株(命名为FZ5),初步鉴定为产碱菌属(Alcaligenessp.),并对菌株FZ5的生长和降解特性进行了研究.结果表明,该菌株最佳生长条件为:温度30℃,pH7.5,培养基装量为250 mL三角瓶装60 mL.在N46机油初始质量浓度为3.5 g.L-1时,培养48 h的降解率为21.86%,培养120 h的降解率为23.96%.此外,降解的广谱性研究发现,该菌株能降解链烷烃,对环烷烃和芳香烃不能降解.     

高效异养硝化细菌的分离筛选及多样性分析

采用生长曲线指导的富集培养法,从生活污水排放渠中分离筛选出高效异养硝化细菌,并对其多样性进行了分析。结果显示,从分离得到的27株异养硝化细菌中筛选出6株高效菌株Ni1-2、Ni1-8、Ni2-5、Ni2-7、Ni3-1和Ni3-4,其48 h氨氮去除率分别为88.9%、76.6%、87.7%、93.1%、99.2%和91.4%;结合菌落形态、革兰氏染色反应、扫描电镜观察和16S r DNA序列分析,发现菌株的种类较为丰富,初步确定Ni1-2和Ni1-8为节杆菌属(Arthrobacter),Ni2-5和Ni3-1为产碱杆菌属(Alcaligenes),Ni2-7为无色杆菌属(Achromobacter),Ni3-4为芽孢杆菌属(Bacillus)。该结果可为高效异养硝化菌的分离筛选及其多样性分析提供参考。     

重组大肠杆菌表达降氰酶的诱导条件优化

采用积分光密度法对产碱杆菌（Alcaligenes sp.）降氰酶基因在大肠杆菌中的高效表达进行了诱导条件优化,以工程菌BL21（DE3）-pET28a-cdE的诱导表达条件进行优化,以提高目的蛋白的产量和活性。结果显示,重组菌表达降氰酶的最佳诱导条件为温度28℃,初始菌体浓度OD600值为0.6,IPTG浓度为0.8mmol/L,诱导时间12h。研究发现,诱导剂的添加浓度对外源蛋白的表达水平具有显著影响,使用终浓度为0.8mmol/L的IPTG,诱导表达12h,降氰酶蛋白收率达到143.27mg/L,比活力达到11560 U/mg。与不添加诱导剂相比,重组蛋白的收率和比活力分别提高了64倍和9倍。     

盐胁迫下粪产碱菌在水稻根表的定殖(英文)

粪产碱菌A1 5 0 1能在氯化钠浓度高达 4%的固体和液体介质中良好生长 ,合成IAA和固定空气中的氮素。当氯化钠浓度超过 3 %时 ,A1 5 0 1丧失运动和趋化能力。一定盐浓度胁迫下A1 5 0 1能定殖在水稻根表和根毛区和侧根伸出部位 ,表现出较高的联合固氮活性。0 5 %的氯化钠能促进A1 5 0 1在水稻根表的定殖能力。A1 5 0 1能通过侧根伸出部位侵入根内。     

Plant Growth-Promoting Rhizobacteria (Pgpr) Increase Yield,Growth And Nutrition Of Strawberry Under High-Calcareous Soil Conditions

Plant growth promoting effects of Alcaligenes 637Ca, Staphylococcus MFDCa-1, MFDCa-2, Agrobacterium A18, Pantoea FF1 and Bacillus M3 were tested on strawberry cv. ‘Aromas’ based on yield, number, and weight of fruit, leaf area, vitamin C, total soluble solids (TSS), acidity and ionic composition of leaves under calcareous soil conditions. The results demonstrated that all of bacterial treatments significantly affected all parameters tested. The best result was obtained from 637Ca treatment, which significantly increased fruit yield, number and weight about 47.5, 34.7, and 9.4%, respectively, compared to control. Except for magnesium (Mg) and zinc (Zn) in the leaf, the concentrations of all plant tissue nutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), iron (Fe), copper (Cu), manganese (Mn), boron (B)] were significantly increased by bacterial treatments tested. The data in the present study showed that all bacterial treatments including Alcaligenes 637Ca, Staphylococcus MFDCa-1, MFDCa-2, Agrobacterium A18, Pantoea FF1, and Bacillus M3 to strawberry plants can ameliorative the deleterious effect of high lime on fruit yield, growth and nutrition. These results suggested that plant growth-promoting Rhizobacteria (PGPR) treatments could be offer an economic and simple means to increased plant resistance for high calcareous soil conditions.     

Developing PGPR consortia using novel genera Providencia and Alcaligenes along with cyanobacteria for wheat

A pot experiment was undertaken using unsterile soil supplemented with the recommended dose of chemical fertilizers in order to investigate the effect of indole-3-acetic acid (IAA)-producing proteo- and cyanobacterial strains on the growth and yield of wheat (Triticum aestivum variety PBW343). Two proteobacterial (WRB4 Providencia sp. and WRB10 Alcaligenes sp.) and two cyanobacterial (WRC3 Anabaena oscillarioides and WRC4 Anabaena torulosa) strains were used individually and in combination. The treatment in which proteobacteriumWRB4 (Providencia sp.) was inoculated showed significantly higher values in comparison with controls for various plant-growth parameters recorded, i.e. shoot length, root length, shoot weight, root weight and crop biomass, followed by the treatment in which the WRC3 (Anabaena oscillarioides) was used. A positive interaction among the proteo- and cyanobacterial strains, in particular WRC3 and WRB4, was also observed by way of enhancement of plant-growth parameters. Significant enhancement in soil microbiological activities such as fluorescein diacetate (FDA) hydrolysis and dehydrogenase activity were recorded in the treatments, particularly in those inoculated with cyanobacterial strains, when compared with fertilizer controls. This is a first-time report on the potential of selected combinations of proteobacterial genera such as Providencia and Alcaligenes and cyanobacteria such as Anabaena as plant growth-promoting organisms in wheat crop.     

生防菌BC2007对番茄促生防病作用的研究

[目的]探讨生防菌BC2007对番茄的促生防病作用。[方法]对重组的基因工程菌BC2007的GFP基因以及苯酚羟化酶基因进行了检测,并通过盆栽试验比较了BC2001和BC2007对番茄的促生防病作用。[结果]生防菌BC2007能减少番茄根系线虫瘤并对番茄的营养生长具有促进作用,也有利于后期产量的形成。[结论]为生物杀线虫菌剂的研制提了供理论依据。     

~(60)Coγ射线诱变选育热凝胶多糖高产菌株的研究

利用60 Coγ射线对产生热凝胶多糖 (Curdlan)出发菌株GM 2 4的菌体细胞与原生质体分别进行辐照处理 ,发现60 Coγ射线对GM 2 4原生质体的诱变效应明显优于对其菌体细胞的作用。对最终诱变筛选获得的 1株高产稳定的Curdlan生产突变株A81研究表明 :与GM 2 4相比 ,其Curdlan产量提高了 5 0 4%,发酵周期缩短了 1 8%,发酵终止后底物残糖由 1 5 3g L降至7 4g L。糖的转化率从 38 7%提高至 5 8 2 %。这说明在Curdlan生产菌株的筛选中60 Coγ辐照是一种有效的方法     

粪产碱杆菌ZWS11菌株对烟嘧磺隆的酶促降解特性

为明确粪产碱杆菌Alcaligenes faecalis ZWS11菌株对烟嘧磺隆的酶促降解特性,采用丙酮沉淀、超声波破碎和高速离心等方法,提取制备了ZWS11菌株的胞外和胞内粗酶液以及菌体碎片悬浮液,并分别测定了其酶活力。结果表明:当V（菌体发酵液）:V（丙酮）=1:3时提取到的胞外粗酶液具有较高的酶活力;胞外粗酶液、胞内粗酶液和菌体碎片悬浮液对24.9 μmol/L烟嘧磺隆的平均降解率分别为87.4%、16.9%和17.4%,胞外粗酶液的降解能力与胞内粗酶液或菌体碎片悬浮液相比差异显著（P<0.05）,由此确定对烟嘧磺隆起降解作用的酶属于胞外酶。最适降解条件研究表明:该降解酶的酶促反应适宜温度为35℃,较适pH值为6.0,反应时间为30 min,在此条件下其对烟嘧磺隆的降解率在80%以上。此外,该降解酶在35～70℃、pH值4.0～9.0范围内均能够保持较高的酶活力,对烟嘧磺隆的降解率均在60%以上,表明该降解酶具有较好的热稳定性和酸碱稳定性。加入不同浓度十二烷基硫酸钠（SDS）和苯甲基磺酰氟（PMSF）,对该降解酶的活力表现出了不同程度的抑制作用。研究结果可为烟嘧磺隆降解酶制剂的规模化生产及被烟嘧磺隆污染土壤的生物修复提供科学依据。