Studies on Rhizospheric Mycoflora of Tea (Camellia sinensis):In vitro Antagonism with Dominant Bacteria

The rhizospheres of established tea bushes have some specificcharacteristics which are associated with the long lived nature of teaplants,viz.,negative rhizospheric effect,lowering of soil pH,antagonistic activities among microbial communities and dominan…     

绿色荧光蛋白基因标记内生枯草芽孢杆菌

用枯草芽孢杆菌168菌株rpsD基因的启动子替换质粒pGFP4412中蜡状芽孢杆菌4412启动子,从而构建了能在枯草芽孢杆菌中表达绿色荧光蛋白基因gfpmut3a的载体pS4GFP,将其导入具有内生、防病、促生作用的野生型枯草芽孢杆菌BS-2菌株中,筛选获得遗传稳定性好且具有良好发光表型的标记菌株BS-2-gfp.该标记菌株在小白菜体内的定殖研究结果表明,该菌株能够在小白菜根际及根、茎、叶内定殖和传导,接菌50d后仍能在其体内分离到标记菌株.图5参17     

无苯酚培养基分离到的降酚菌多样性的分子分析

用3种不含苯酚的培养基(YPG、10%YPG和LB)从上海焦化厂废水处理系统(A2/O法)好氧池的悬浮污泥分离到24株降酚菌株.通过16SrDNAPCR扩增产物的限制性酶切分析(amplifiedribosomalDNArestrictionanalysis,ARDRA)、ERICPCR指纹图谱分析、多组分苯酚羟化酶大亚基(thelargestsubunitofthemulticomponentphenolhydroxylase,LmPH)基因的PCR扩增及16SrRNA基因测序的方法对这些降酚菌株进行表征.通过ARDRA分型,将这24株降酚菌株分为8个类型;利用ERICPCR可以将这24个菌株分为17种类型,说明同一ARDRA类型内菌株具有多样性.对17个ERIC类型代表菌株的16SrDNA扩增产物进行克隆并测序,测序结果在GenBank和RDP中进行比对.结果表明,与这17个代表菌株同源性最高的菌中,有6株是未见报道具有降酚功能的菌株.在这24株降酚菌中,有19株在苯酚含量为200mg/L的MP培养基中培养5d,苯酚降解率为20%左右,其余5株苯酚降解率达到100%,且均属于Rhodococcus属.本研究在降酚菌生物多样性上作了有益的探索.图2表1参20     

优势工程菌在H/O工艺中处理制药废水的研究

采用水解 (H)—好氧 (O)生化工艺研究了优势复合工程菌对抗生素工业废水有机质的降解能力并进行了处理条件试验研究。探讨了预处理、生化温度、pH值、水力停留时间、进水有机物浓度等因素对生化处理工艺的影响。试验结果表明 ,在选定的条件下 ,水解单元COD的降解率达 71 9%。好氧单元COD的降解率达 62 9% ,总去除率达 98 5%。达到国家规定的制药行业排放标准 ,出水的COD平均浓度低于 30 0mg/L。     

异养菌与新型填料成膜性及BTF处理屠宰H2S废气

以新型填料上生物膜的微生物种群结构为研究对象,将异养脱硫细菌蜡状芽孢杆菌ZJNB-B3接种到含活性污泥和LEVAPOR新型填料的小试曝气液体反应器,研究此菌在活性污泥及在填料生物膜中的微生物多样性.在属分类水平上的物种分析结果表明,芽孢杆菌属在接种后的填料中相对丰度较高,而在活性污泥样品中相对丰度较低,其在培养了第10d的填料样品中已经达到最大相对丰度.因此该菌与新型填料的亲和性和成膜性较好.将该菌与新型填料应用于生物滴滤塔（BTF）处理屠宰污水站排放的H₂S恶臭废气,风量处理能力为2000m³/h.结果表明,经该菌强化的BTF完成启动的时间比使用普通活性污泥接种的BTF缩短7d.强化的BTF在30d的稳定期试验中,当H₂S进气浓度为4.92~9.54mg/m³时,对H₂S去除率为98%~99%.当进气H₂S在1.0~10mg/m³范围波动时,空床停留时间（EBRT）为10,21,30s时,去除率分别为94%、98%、99%以上,且受进气H₂S浓度波动的影响不大.当进口负荷为0.60~1.14g/（m³·h）时,H₂S去除率稳定在98%以上,H₂S气体排放量低于恶臭污染物排放国家标准.     

固定化溶藻菌除藻效果研究

为了解固定化溶藻菌对藻类污染水源的治理效果,模拟动态膜生物反应器,将溶藻细菌RZ14菌株固定于膜组件,通过膜自生功能形成溶藻菌生物膜。采集水华水体作为进水水样,对水体中叶绿素a、有机质、氨氮及总磷变化进行跟踪测定。结果表明:结合DMBR工艺,投加溶藻菌RZ14菌株后,叶绿素a含量低于0.05mg/L,去除率接近100%,COD及BOD5去除率分别为50.08%和71.24%,氨氮及总磷去除率分别为70.73%和86.79%。将溶藻菌投加动态膜生物反应器,能快速消除水华现象,改善水质污染状况,对藻类污染水体治理效果显著。     

Isolation,identification and desulfurization mechanism of a sulfur-oxidizing bacterium with salt tolerance北大核心CSCD

Micro-organism with efficient desulfurization performance is a key factor in the biological desulfurization technology. This study aimed to seek such a sulfur-oxidizing strain and understand its desulfurization mechanism. Wastewater in a sewage station of natural gas purification plant was used to screen the sulfide-oxidizing strain, and to identify it based on sequence similarity analysis of 16S rDNA and the morphological characteristics. Thiosulfate was used as substrate for investigating the sulfur oxidation performance and salinity tolerance; the OD600, content change of thiosulfate, sulfate, sulfur, pH and total alkalinity in the cultural system were also investigated. The strain DS-B was found to share the highest sequence similarity with Thioalkalivibrio thiocyanoxidans ARh2, therefore determined as Thioalkalivibrio. At the optimum temperature of 35 °C for growth and degradation, the removal efficiency of thiosulfate could reach 98.7% after 7 days. Strain DS-B had strong resistance to thiosulfate, and the optimal concentration of S2O32- was 2 × 104 mg/L. The analysis for sulfur oxides showed that it could oxidize thiosulfate by the pathway of S2O32-→SO42- / S2O32- → S → SO42-. Therefore the strain DS-B is a sulfur-oxidizing bacterium with great application prospect for its strong salt tolerance and conspicuous removal capability for thiosulfate.     

芽孢杆菌SeRB-2还原亚硒酸盐的动力学研究

微生物还原亚硒酸盐的动力学研究具有重要的现实意义,可以为Se (IV)污染场地的微生物修复设计提供理论依据。本文研究了兼性厌氧菌Bacillus sp.SeRB-2对亚硒酸钠的还原动力学。通过指数方程模型、对数方程模型和米氏方程模型的分析可知,Se (IV)的细菌还原符合一级反应动力学,还原反应主要集中在对数期和稳定生长前期,米氏方程模型能更好的反映细菌对亚硒酸盐的还原过程。通过对不同Se (IV)浓度下的米氏常数(K_m)和最大反应速率(V_max)的分析发现,当Se (IV)浓度较低时,K_m值较小,V_max值较大,这表明Se (IV)浓度越低,还原亚硒酸盐的酶与Se (IV)的结合能力越强,此时细菌对亚硒酸盐的还原速率越大、还原效率也越高。在本研究中,当Se (IV)浓度为1 mmol/L时,其还原效率最高可达90%,能够有效去除或降低Se (IV)污染,说明该菌在Se (IV)污染场地的生物修复上具有应用潜力。     

Characterization of a salt-tolerant bacterium Bacillus sp. from a membrane bioreactor for saline wastewater treatment

High salt concentrations can cause plasmolysis and loss of activity of cells, but the salt-torlerant bacterium can endure the high salt concentrations in wastewater. In this research 7 salt-torlerant bacteria, which could survive in dry powder products and could degrade organic contaminants in saline wastewater, were isolated from a membrane bioreactor. The strain NY6 which showed the fastest growth rate, best property for organic matter degradation and could survive in dry powder more than 3 months was selected and characterized. It was classified as Bacillus aerius based on the analysis of the morphological and physiological properties as well as the 16 S rRNA sequence and Neigh borjoining tree. The strain NY6 could survive in the salinity up to 6% and the optimal growth salinity is2%; it belongs to a slightly halophilic bacterium. The capability of its dry powder products for COD removal was 800 mg COD/(g·day) in synthesized saline wastewater with salinity of 2%. According to salt-tolerant mechanism research, when the salinity was below 2%, the stain NY6 absorbed K+and Na+to maintain osmotic equilibrium, and when the salinity was above 2%, the NY6 kept its life by producing a large amount of spores.     

固定化高效降解菌处理PTA废水的研究

研究了聚乙烯醇(PVA)加少量海藻酸钠及SiO2、CaCO3的方法固定高效菌处理PTA污水.结果表明,采用质量分数分别为PVA 10%、海藻酸钠0.3%、特种菌种10%、SiO2 3%、CaCO30.3%,用饱和硼酸溶液(pH为4.0)作为交联剂,制得的颗粒处理PTA废水时,废水COD负荷为2.91kg/m3·d时,CODcr、TOC、TA去除率均为85%以上;废水COD负荷为12.2kg/m3j·时,CODcr去除率仍为50%以上、TOC去除率为60%以上,当pTA废水pH从55降至35时,CODcr、TOC、TA去除率仍在86%以上.