高效优势降解菌处理樟脑废水

针对樟脑废水,从活性污泥中筛选出降解樟脑废水的高效优势菌,通过分离纯化,优选出3株适应能力强、生长旺盛的菌株,分别为ZH-1、ZH-2、TZH-2。经初步鉴定分别为动胶菌属、假单胞菌属、短杆菌属。试验测定了樟脑混合菌最佳生长条件的优化组合为:葡萄糖质量浓度20 g.L-1,温度30℃,pH值为7,转速为125 r.m in-1,培养时间55 h。并测定了单株菌和混合菌对樟脑废水的降解效果,结果表明混合菌的降解效果最为明显,降解率为75.23%。     

流化床在生物物料热力干燥中的应用

干燥是许多生物制品的最后一道工艺操作过程。由于大多数生物制品均具有热敏和湿敏的特性,干燥方法和操作参数的选择对于生物制品活性的保存非常重要。本文通过光合菌液和复合生物饲料干燥的研究表明,流化床干燥器适用于光合菌液和复合生物饲料的干燥,干燥后产品可保持较高活性。     

微生物絮凝剂普鲁兰去除原水浊度的技术研究

为了确定微生物絮凝剂普鲁兰的最佳絮凝除浊条件,采用正交试验,分析了原水浊度、药品投加量、水力条件、pH值、水温等对絮凝除浊的影响。结果表明,最佳絮凝除浊条件是:原水浊度大于1000NTU,普鲁兰投加量2.0mg/L,硫酸铝投加量10mg/L,搅拌强度200r/min,pH值5.0～8.5,水温5～35℃。     

甲氰菊酯的酶促降解

阴沟肠杆菌w10j15中提取到甲氰菊酯降解酶,测定了其对甲氰菊酯的降解特性。研究结果表明,降解酶在40℃、pH7 5时对甲氰菊酯显示最大的降解活性,对甲氰菊酯的降解率为65%。经实验测定,其每毫克酶蛋白质最大降解速率Vmax为48 08 nmol·mL-1·min-1,米氏常数(Km)为332 23 nmol·mL-1。     

优势菌对焦化废水中COD和氨氮处理的研究

为了提高焦化废水的生物降解率,采用活性污泥作菌种,对活性污泥的梯度驯化、优势菌的筛选和分离鉴定进行了探索性研究.结果得到5株优势菌,其中3株属于假单胞菌属,另外两株分别属于硝化杆菌属和微球菌属.对这5株的单一菌及其不同组合的混合菌进行了焦化废水降解对比实验.结果表明,焦化废水经优势菌处理48h后,COD的最高降解率为81.1%,氨氮为51.2%,初步得出:以焦化废水作为碳氮来源的梯度驯化法用于优势菌的筛选很有效.     

生物法去除水中重金属离子的研究

微生物去除水中的重金属离子是微生物利用一个新的研究领域,微生物的这种性质在处理含有重金属离子的废水溶液中具有广阔的应用前景。本文对微生物去除重金属离子的原理,去除过程中的影响因素：溶液pH值、重金属离子的初始浓度、生物去除剂的预处理、去除时间、去除温度以及重金属离子的回收和重复使用等作了详细的综述。     

间作下根际微生物控制土传病害的研究进展

为了解根际微生物在间作模式下有效控制土传病害的作用和机理,综述了间作系统对于根际微生物群落结构和代谢功能的影响,介绍了间作作物组合、作物品种选择和间作方式对根际微生物群落的影响,并从养分和宿主感染位点竞争、生防微生物的拮抗作用、植物化感自毒作用的缓解以及植物诱导系统抗性四个方面总结了与根际微生物相关的间作抗病机理。最后,讨论了现阶段间作抗病研究的局限性并对今后的研究方向进行了展望。     

Differences in Soil Properties and Bacterial Communities between the Rhizosphere and Bulk Soil and among Different Production Areas of the Medicinal Plant Fritillaria thunbergii

To explore rhizosphere effects, geographical differences and their effects on the bacterial community associated with the geoherb Fritillaria thunbergii, some physicochemical properties of soil samples (3 sampling sites × 2 habitats (rhizosphere and bulk soil)) were measured and the soil bacterial community detected by PCR-denaturing gradient gel electrophoresis (DGGE). Among the three regions, soil pH varied between 4.48 and 7.73 indicating that F. thunbergii could grow both in acid and slightly alkaline soil. As the authentic Dao-di producing area, Ningbo showed the highest soil quality with the highest content of organic matter (OM) (2.46%), phosphatase (268 mg kg(-1) 24 h(-1)) and urease activity (1481 mg kg(-1) 24 h(-1)). In comparison with the bulk soil, pH, organic carbon content, and phosphatase and urease activities were all lower in the rhizosphere, suggesting that the roots may secrete some unique metabolites in root exudates. Statistical analyses showed that soil properties of Ningbo and Panan in Zhejiang province were more similar to each other than those in Nantong in Jiangsu province. In addition, PCR-DGGE analysis showed that main bacterial population identified in F. thunbergii was proteobacteria (18 bands, 55%), acidobacteria (4, 12%), actinobacteria (4, 12%) and bacterioidetes (6, 18%). Overall, soil properties and microbial communities varied not only between the rhizosphere and bulk soil but also among the three regions. We suggest that the plant, together with the soil properties, cooperatively shape the structure of the rhizosphere bacteria, and that the soil properties have a close relationship with the geoherbalism of F. thunbergii.     

Genetic Diversity and Phylogeny of Antagonistic Bacteria against Phytophthora nicotianae Isolated from Tobacco Rhizosphere

The genetic diversity of antagonistic bacteria from the tobacco rhizosphere was examined by BOXAIR-PCR, 16S-RFLP, 16S rRNA sequence homology and phylogenetic analysis methods. These studies revealed that 4.01% of the 6652 tested had some inhibitory activity against Phytophthora nicotianae. BOXAIR-PCR analysis revealed 35 distinct amplimers aligning at a 91% similarity level, reflecting a high degree of genotypic diversity among the antagonistic bacteria. A total of 25 16S-RFLP patterns were identified representing over 33 species from 17 different genera. Our results also found a significant amount of bacterial diversity among the antagonistic bacteria compared to other published reports. For the first time; Delftia tsuruhatensis, Stenotrophomonas maltophilia, Advenella incenata, Bacillus altitudinis, Kocuria palustris, Bacillus licheniformis, Agrobacterium tumefaciens and Myroides odoratimimus are reported to display antagonistic activity towards Phytophthora nicotianae. Furthermore, the majority (75%) of the isolates assayed for antagonistic activity were Gram-positives compared to only 25% that were Gram-negative bacteria.     

微生物凝固天然橡胶交联密度的研究

采用核磁共振交联密度仪,考察了微生物凝固天然橡胶（NR-m）和酸凝固天然橡胶（NR-a）在硫化过程交联密度（XLD）、网链含量（AMc）、自由小分子含量（AT2）以及相邻交联点间的分子质量（Mc）的动态变化规律。研究结果表明,NR-m硫化胶的XLD比NR-a的高,NR-m硫化胶磁化曲线随时间衰减的速率比NR-a快,纵向松弛时间（T1）和横向驰豫时间（T2）比NR-a低,NR-m硫化胶网链部分的质量含量（AMc）明显高于NR-a的,而自由末端数则明显比NR-a的低。这表明微生物凝固法促进了天然橡胶的硫化作用,提高了硫化胶的交联密度。