一株降解除草剂膦化麦黄桐(PPT)菌的筛选与鉴定

从喷洒有除草剂的土壤中分离到一株能分解膦化麦黄桐(PPT)的细菌.该菌在以PPT为唯一碳源的培养基上生长,能利用PPT的最高浓度为2. 7g/L.采用常规生理生化鉴定方法,并结合16SrDNA序列分析法对该菌进行鉴定.结果表明,该菌与生癌肠杆菌(Enterobactercancerogenus)序列相似性为99. 3%,在细菌分类学上属于肠杆菌.将它命名为Enterobactersp. PPT. 图4表2参7     

Uptake of copper ion by activated sludge and its bacterial community variation analyzed by 16S rDNA

The effect and uptake of copper ion on SBR(sequence batch reactor)biological treatment system was studied.special nutrient and powder activated carbon(PAC)additive were tested as uptake stimulation technique.Results showed that copper ion had higher effect on unacclimated activated sludge system than on acelimated one.The special nutrient adding could enhance the uptake of copper significantly,while PAC adding could improve the sludge settling and decrease the turbidity of effluent.The variation of bacterial community analyzed by 16S rDNA method showed the acclimation of copper could increase copper resistance species,and excess accumulation could cause some species diminish.It was confirmed that acclimation could improve the resistance and uptake ability of microorganism to heavy metal.     

1,2,4-三氯苯降解菌的分离及其降解质粒的研究

 以1,2,4-三氯苯为唯一碳源,从天津化工厂氯苯生产车间的土壤中分离到1株1,2,4-三氯苯的降解菌THSL-1.通过形态观察和16SrDNA序列测定,该菌株被初步鉴定为施氏假单胞菌(Pseudomonasstutzeri).经质粒检测,在菌株THSL-1中发现1条质粒条带,将所获得质粒转化到E.coli.JM109中,转化子能以1,2,4-三氯苯为唯一碳源生长,且对1,2,4-三氯苯有降解作用.因此,可以认为该质粒携带降解1,2,4-三氯苯的基因.选用HindIII、BamHI、XholI3种限制性内切酶分别对质粒pTHSL-1进行单酶切、双酶切,最终确定质粒平均大小为40.2kb.     

Bioleaching of spent Ni-Cd batteries and phylogenetic analysis of an acidophilic strain in acidified sludge

Biohydrometallurgy is a novel method to recycle discarded batteries, in which sewage sludge is used as microorganisms and culture due to the presence of indigenous Thiobacilli. A two-step continuous flow leaching system consisting of an acidifying reactor and a leaching reactor was introduced to achieve the bioleaching of spent nickel-cadmium (Ni-Cd) batteries. The acid supernatant produced in the acidifying reactor by the microorganisms with ferrous ions as the substrate was conducted into the leaching reactor to dissolve electrode materials. The efficiency of a batch treatment of batteries was examined. The results showed that the complete dissolution of two AA-sized Ni-Cd batteries with 0.6 L/d acid supernatant took about 30, 20, and 35 days for Ni, Cd, and Co, respectively. But the dissolution ability of the three metals was different. Cd and Co can be leached mostly for pH below 4.0 while the complete dissolution of Ni can be achieved for pH below 2.5. Meanwhile, a strain (named Thiooxidans. WL) accounting for the reduction of pH in the acidified sludge was isolated and sequenced. It was identified to be 100% similar to Acidithiobacillus ferrooxidans strain Tf-49 based on 16S rDNA sequence analysis. The relevant phylogenetic tree constructed indicates that the strain should be classified into genus Acidithiobacillus ferrooxidans.     

高通量测序技术应用于污水处理厂细菌气溶胶群落结构分析

由于污水及其处理设施中细菌气溶胶的逸散作用,导致污水处理厂细菌气溶胶的群落结构较为复杂,因此,选择适宜的采样和分析方法对其多样性的认识和风险评估具有重要意义.本研究以某城市污水厂为研究对象,采用"总悬浮颗粒物采样器+高通量测序技术"分别对污水处理全过程进行细菌气溶胶的收集与分析;作为对照,采用"Andersen六级采样器+克隆文库技术"进行同步采样和分析.结果表明,前者对各采样点气溶胶中细菌的多样性、总体群落组成、优势群落的解析均明显优于后者,分析更简便快捷,数据更全面、更接近其真实的分布状态.本研究结果可为污水处理厂细菌气溶胶的采样和分析方法的选择提供科学依据.     

水稻不同生长时期不同组织中抗砷内生菌的筛选与鉴定

微生物对于土壤-植物系统中砷的迁移转化有重要作用,植物内生菌是一种极其丰富的微生物资源,但至今尚未有研究报道植物内生菌对砷污染的响应.采用组织分离法和涂布平板法,以水稻(甬优-538)为研究对象,分别于水稻幼苗期、分蘖期、开花期和成熟期(2015年5~8月)分离根部、茎部、叶部、穗部(仅成熟期)可培养内生细菌,并通过16S r DNA序列进行菌种鉴定.对分离所得内生菌先用1 mmol·L~(-1)亚砷酸钠[As(Ⅲ)]和10 mmol·L~(-1)砷酸钠[As(Ⅴ)]进行抗砷筛选,再用2mmol·L~(-1)的As(Ⅲ)和20 mmol·L~(-1)的As(Ⅴ)对初筛抗砷菌株进行复筛,以鉴定内生菌对不同砷形态的抗性.结果表明:共获得126株水稻内生菌,归为13个属,水稻幼苗期分离出8个属共37株菌;分蘖期分离出5个属共25株菌;开花期分离出8个属共24株菌;成熟期分离出8个属共30株菌.主要优势菌属为芽孢杆菌属(Bacillus sp.)、假单胞菌属(Psoudomonas sp.)和不动杆菌属(Acinetobacter sp.).抗砷初筛选实验中得到20株菌对1 mmol·L~(-1)的As(Ⅲ)和10 mmol·L~(-1)的As(Ⅴ)的抗性较强,复筛发现其中16株菌对2 mmol·L~(-1)As(Ⅲ)有较强抗性,13株菌对20 mmol·L~(-1)As(Ⅴ)有较强抗性,其中菌株CS1对两种形态砷的耐性最显著.     

一株DEHP降解菌的筛选和分子鉴定

采用富集培养法从污水厂活性污泥中分离得到一株能以邻苯二甲酸二(2-乙基己基)酯(DEHP)为唯一碳源的细菌。该菌在48 h内可将DEHP浓度从20 mg/L降解到2 mg/L。对其进行了生理生化试验和分子生物学鉴定。结果表明,该菌株呈丝状,革兰氏阳性,好氧,能在45℃下生长。该菌株与长孢糖丝菌模式菌Saccharothrix longispora DSM 43749在同一分枝上,同源性为98.9%;与糖丝菌属(Saccharothrixsp)内其他种同源性均在97.0%以上。     

一株产黑色素海洋细菌的筛选、鉴定及发酵条件优化

从山东近岸海域海水中分离得到一株产黑色素细菌Sl,通过对S1菌株的菌落形态观察、生理生化性质检验及16SrDNA序列测定,初步鉴定为明亮发光杆菌(Photobacterium phosphoreum).为了提高S1菌株黑色素产量,采用单因素实验设计对S1菌株进行发酵条件优化,结果表明当发酵条件为L-酪氨酸0.75 g/...     

一株产黑褐色色素海洋放线菌的研究

从舟山群岛潮间带海域中分离到一批产色素的海洋放线菌,用滤纸片法进行抑菌试验,并对目标菌株进行鉴定,然后对其所产色素进行粗提,测色素的最大吸收波长,研究理化因子对其影响.结果表明筛选到产黑褐色色素的菌株B2,其对Vibrio parahaemolyticus和Escherichia coli具有较好的抑制作用,色素初步研...     

Detection, isolation, and identification of cadmium-resistant bacteria based on PCR-DGGE

This study focused on the screening of cadmium-resistant bacterial strains from Pb-Zn tailing. We investigated the diversity of microbial community inhabiting Dong-san-cha Pb-Zn tailing in Beijing, China, by polymerase chain reaction-denaturing gradient gel electrophoresis （DGGE） of 16S rRNA gene of bacterial strain, and found two dominant strains in the DGGE profile. Using special culture media, we isolated two strong cadmium-resistant bacterial strains. On the basis of morphological, physiological, and biochemical characteristics, BIOLOG, and 16S rDNA sequencing, the two strains were identified as Bacillus cereus and Enterobacter cloacae. Minimal inhibitory concentrations （MICs） of heavy metals for the bacteria were determined. E. cloacae showed higher MIC values for heavy metals and a larger range of antibiotic resistance than B. cereus.