Toxicity evaluation of 10 oil gelling agents北大核心CSCD

Oil gelling agents are widely used in emergency response of marine oil spills. However, the biological toxicity of oil gelling agents is not well understood. This research aimed to evaluate the environmental safety of oil gelling agents used for rapid removal and cleanup of marine oil spills. We used luminescent bacteria (Acinetobacter sp. Tox2 and Acinetobacter sp. RecA) combined with exposure experiment using marine medaka (Oryzias melastigma) juveniles to detect the acute toxicity and genotoxicity of 10 oil gelling agents. As a result, a certain level of acute toxicity was detected from the oil gelling agent FOA and GMN-01 (the toxicity equivalent to 0.067 mg/L and 0.084 mg/L of HgCl2, respectively), and a certain level of genotoxicity was detected from the oil gelling agent NORSOREX (the toxicity equivalent to 0.307 mg/L of MMC) by the luminescent bacteria test. However, no obvious acute toxicity or genotoxicity was detected from the above three oil gelling agents in fish-exposure experiments. Our results suggest that the 10 oil gelling agents have no obvious acute toxicity or genotoxicity to higher organisms (including marine medaka). The luminescent bacteria test is more sensitive in detecting biological toxicity of oil gelling agents. This study provides a reference for environmental safety evaluation of the oil gelling agents used in the cleaning up of the marine oil spills.     

Mg2+ improves biomass production from soybean wastewater using purple non-sulfur bacteria

Soybean wastewater was used to generate biomass resource by use of purple non-sulfur bacteria(PNSB). This study investigated the enhancement of PNSB cell accumulation in wastewater by Mg2+under the light-anaerobic condition. Results showed that with the optimal Mg2+dosage of 10 mg/L, biomass production was improved by 70% to 3630 mg/L,and biomass yield also was improved by 60%. Chemical Oxygen Demand(COD) removal reached above 86% and hydraulic retention time was shortened from 96 to 72 hr. The mechanism analysis indicated that Mg2+could promote the content of bacteriochlorophyll in photosynthesis because Mg2+is the bacteriochlorophyll active center, and thus improved adenosine triphosphate(ATP) production. An increase of ATP production enhanced the conversion of organic matter in wastewater into PNSB cell materials(biomass yield) and COD removal, leading to more biomass production. With 10 mg/L Mg2+, bacteriochlorophyll content and ATP production were improved by 60% and 33% respectively.     

影响硝化细菌养殖水污染处理的因素分析研究

为了进一步探讨优化养殖水污染的治理技术,文中介绍了养殖水污染的来源及其成分,提出了相关硝化细菌的基本内容,阐述分析了硝化细菌的保存、分离和污水处理效率等一些相关的影响因素,同时提出可以影响硝化细菌在养殖水污染处理中的因素,这些因素主要有硝化细菌的分离纯化、硝化细菌如何进行保存、硝化细菌如何进行鉴定和硝化细菌如何进行养殖污水处理效率的影响因素,将对进一步提高养殖污水处理效率,促进养殖水污染治理提供一定的帮助.     

Genomic analyses of metal resistance genes in three plant growth promoting bacteria of legume plants in Northwest mine tailings, China

To better understand the diversity of metal resistance genetic determinant from microbes that survived atmetal tailings in northwest of China, a highly elevated level of heavymetal containing region, genomic analyses was conducted using genome sequence of three native metal-resistant plant growth promoting bacteria (PGPB). It shows that: Mesorhizobium amorphae CCNWGS0123 contains metal transporters from P-type ATPase, CDF (Cation Diffusion Facilitator), HupE/UreJ and CHR (chromate ion transporter) family involved in copper, zinc, nickel as well as chromate resistance and homeostasis. Meanwhile, the putative CopA/CueO system is expected to mediate copper resistance in Sinorhizobium meliloti CCNWSX0020 while ZntA transporter, assisted with putative CzcD, determines zinc tolerance in Agrobacterium tumefaciens CCNWGS0286. The greenhouse experiment provides the consistent evidence of the plant growth promoting effects of these microbes on their hosts by nitrogen fixation and/or indoleacetic acid (IAA) secretion, indicating a potential in-site phytoremediation usage in themining tailing regions of China.     

一株高效产絮菌的筛选、絮凝条件优化及对重金属废水处理性能研究

从活性污泥、水体底泥、植物根系土壤和草莓种植土壤中筛选、分离、纯化,获得了高絮凝活性的菌株,并考察发酵液用量、助凝剂用量以及碳、氮源种类对絮凝活性的影响及菌株对实际重金属废水的絮凝作用。结果表明:以葡萄糖为碳源,酵母膏为氮源,菌体发酵液用量0.2 m L,助凝剂用量0.8 m L时,菌株QB1的絮凝性最高,可达到93%。其对多种重金属废水均具有较好的处理性能,对含铅废水的去除率最高可达99%以上。     

纳米材料对环境中微生物活性的影响研究

研究纳米材料对环境中微生物细胞活性的影响可为纳米材料的生物安全性评价提供一定的理论基础.以大肠杆菌和枯草芽孢杆菌为受试生物,采用电导率仪测定细菌培养液电导率变化,分别研究了纳米TiO2、纳米ZnO、纳米Fe3O4、纳米SiO2、纳米二氧化钛载银、纳米磷酸锆载银、纳米棕色银对细菌细胞膜通透性的影响.结果表明,纳米材料对革兰氏阳性枯草芽孢杆菌细胞活性影响更大;同种纳米材料,粒径越小,对细菌的细胞活性影响越强;对细菌细胞活性影响最大的是纳米棕色银,对细菌细胞活性影响最小的是纳米SiO2和Fe3O4.     

24孔板发酵法测定地表水和废水中粪大肠菌群的研究

对地表水和废水中粪大肠菌群的多管发酵法进行了改进。改进了初发酵方法,采用24孔板代替试管进行初发酵,复发酵方法保持不变。对环境中采集的23个污水样本采用24孔板初发酵法与多管发酵法进行比较,结果表明,两种方法相关性良好,两者在结果上无统计学意义的差别。采用改进的24孔板法进行初发酵有效节约了培养基、缩短了实验准备时间,简化了操作步骤,尤其适用于大批量的、污染严重的地表水和废水中粪大肠菌群的检测。     

产絮菌H8絮凝条件的优化

在实验室条件下对产絮菌H8絮凝条件进行优化,得出所需最佳碳源为葡萄糖;最佳复合氮源为酵母菌+蛋白质;最佳生长环境PH为8;培养温度为10℃,培养时间为20h。最佳絮凝条件:高岭土PH为9.0;助凝剂为Ca2+,加入Ca Cl2的最佳浓度为0.04%,菌液投加量为2%,静沉时间5min。     

河蚬（Corbicula fluminea）扰动对表层沉积物中氨氧化菌群落结构和丰度的影响

为研究不同生物量河蚬(Corbicula fluminea)的生物扰动对表层沉积物中氨氧化菌群落结构和丰度的影响,本研究设计了沉积物-水微宇宙的模拟体系,通过构建克隆文库、实时荧光定量PCR(real-time qPCR)等分子生物学方法比较不同密度河蚬扰动的沉积物中氨氧化古菌(ammonia-oxidizing archaea,AOA)和氨氧化细菌(ammonia-oxidizing bacteria,AOB)群落结构和丰度差异.结果表明,河蚬的生物扰动作用对表层沉积物氮素释放有明显的促进作用.氨氧化菌(AOA和AOB)amoA基因克隆文库中,AOA的amoA基因序列包含了已知的海洋和土壤环境中的两个分支,AOB的amoA基因绝大部分序列都属于变形菌门β亚纲(β-Proteobacteria)中的亚硝化单细胞菌属(Nitrosomonas).3个处理组表层沉积物中细菌amoA基因丰度均高于古菌amoA基因丰度,且河蚬密度越高则细菌amoA的丰度越低.同时,河蚬的添加使得微宇宙体系中氨氧化菌(AOA和AOB)的多样性降低.综上,河蚬的生物扰动对表层沉积物中氨氧化菌群落结构和丰度产生了一定的影响.     

厌氧氨氧化菌与其他细菌之间的协同竞争关系

随着污水脱氮行业的蓬勃发展,各种新工艺、新理论层出不穷.厌氧氨氧化(Anammox)工艺以其独特的优点脱颖而出,成为最具应用前景的新工艺.厌氧氨氧化菌作为该过程的执行者目前已发现5属17种,本文主要对5属17种的厌氧氨氧化菌进行总结,并对厌氧氨氧化菌种内关系中的群体感应系统进行详细介绍,此外还介绍了厌氧氨氧化菌与硝化菌、反硝化菌以及厌氧甲烷氧化菌之间的协同与竞争关系.最后给出常见竞争因素对厌氧氨氧化种群结构的影响,通过控制竞争因素来实现对厌氧氨氧化种群结构的调节.本文将厌氧氨氧化菌微生物生态学与厌氧氨氧化污水处理工艺相结合,为厌氧氨氧化工艺在污水生物处理中的应用提供理论依据.