Isolation and identification of a bacteria strain Enterobacter cloacae I7 for degradation of hydrolyzed polyacrylamide

A bacteria strain for the degradation of hydrolyzed polyacrylamide (HPAM) was isolated from a curing pot in HPAM distribution station of Daqing Oilfield using Hungate anaerobic technique.The isolate was investigated from morphological,physiological,biochemical and molecular characterization.It is a Gram-negative,short-bacillus,non-spore-forming anaerobic bacteria with an optimum growth at 8.0 pH at 40℃.It can reduce sulfate to H2S.Alignment of 16S ribosomal DNA and 16S-23S ribosomal DNA intergenic spacer sequences suggests that this isolate is closely related to the Enterobacter cloacae.The isolate is identified as a new strain belonging to Enterobacter genus,temporarily named as Enterobacter cloacae I7.Analysis results of infrared spectroscopy (IR) show that the bacteria can use HPAM as the only carbon source,change the structure of HPAM polymer surface,and realize the hydrolysis of amide to carboxyl group by hydrolysis mechanism.It can degrade the side chain and change some functional groups,which obviously decreases the viscosity.GC-MS analysis indicates that the determined low-molecular weight degradation products of HPAM are polyacrylamide fragments with duplet bond,epoxy as well as carbonyl group,but most of them are acrylamide oligomer derivatives.     

基于nir S基因的反硝化细菌快速定量检测

为解决现有油田污水以及反硝化相关的生物反应器中,反硝化细菌定量检测周期长、检测费用高的问题,以nir S基因为靶基因,采用聚合酶链式反应(PCR)技术与倍比稀释法(MPN)相结合的nir S-MPN-PCR法,对反硝化细菌进行快速定量检测研究.从污水中制备直接用于PCR扩增的菌液,保证定量准确性;以832F和1606R为通用引物,优化反应体系和扩增条件.结果表明,该方法检测结果明显比MPN-Gries法灵敏,真实地反映污水中实际的DNB菌的数量,整个操作过程需要3～4h,检测结果非常稳定,降低了检测费用,可以在生产工艺中应用.     

一株好氧反硝化细菌的分离与鉴定试证

为筛选好氧反硝化细菌,采用SBR反应器,通过间歇曝气方式对活性污泥体系中好氧反硝化细菌进行选择和富集,从污泥中筛选出一株好氧反硝化细菌f4,该菌株在完全好氧的条件下可高效地将NO3-N反硝化为N2,对NO3-N去除率达到90%以上,并不产生NO2-N的累积,反硝化过程或氮气生成过程都发生在对数生长期,其培养特征为ORP降低和反硝化产碱.经过生理生化鉴定和16SDNA测序,建立系统发育树,可基本确定分离的菌株f4Pseudomonas.sp.     

Performance of BAC process for treatment of micro-polluted water

Biological activated carbon （ BAC ） has been developed on the granular activated carbon by immobilization of selected and acclimated species of bacteria to treat the micro-polluted water. The BAC removal efficiencies for nitrobenzene, permanganate index, turbidity and ammonia were investigated. Effects of shock loading and SEM （Scanning Electron Microscope） observation on BAC were studied. Backwashing and its intensity of BAC were also discussed. The results showed that BAC took short time to start up and recover to the normal condition after shock loading. The shock loading studies showed that the removal efficiency of BAC was not completely inhibited even at high concentration of nitrobenzene. Backwashing performed once every 10 -20 d, or an average of 15 d. Backwashing intensity was 12 - 14 L/（ s · m^2 ） with air and 3 - 4 L/（ s· m^2 ） with water.     

Isolation and phylogenetic analysis of heterotrophic nitrobacteria

A method about the isolation of heterotrophic nitrosobactria and the characteristics of heterotrophic nitrosobactria were studied. It can be seen from the fluorescence in situ hybridization results of the bio-membrane sample from the bio-ceramic reactor, the spots of green nitrosobacteria are obviously more than those of orange nitrobacteria. Two heterotrophic nitrobacteria were isolated from the bio-ceramic reactor. By sequencing 16SrDNA and establishing the phylogenic tree, they were identified physiologically and biochemically as Pseudomonas sp.. After 12 d, the COD removal efficiency of wgy55 and wgy68 were 45.03% and 50. 85% , the NH4-N removal efficiency of them were 80. 12% and 85.93% , and the TN removal efficiency of them were 69. 71% and 64. 7%. The final concentration of NO2-N of wgy55 and wgy68 was 0. 753 mg/L and 0. 601 mg/ L, and that of NO3-N was 3.21 mg/L and 3.38 mg/L. These results show that wgy55 and wgy68 have the capability of nitrification and they are heterotrophic nitrobacteria.     

松花江水内分泌干扰物及雌激素活性调查

为明确松花江水体中内分泌干扰物的污染状况,利用固相萃取富集-气质联机/重组基因酵母对松花江全江11个典型断面进行全面采样分析.结果表明：江水中∑5ES质量浓度在6.59～30.97 ng/L,平均值为17.23 ng/L,出现最大质量浓度的位置是达连河排污口,雌酮（E1）和雌二醇（E2）是其中贡献最大雌激素,其质量浓度...     

反硝化聚磷菌富集、筛选及其特性

为进一步探讨反硝化除磷机理和提供脱氮除磷功能菌株,对A2SBR快速富集驯化并筛选其中反硝化聚磷菌功能菌.采用控制A2SBR进水及运行方式对反硝化聚磷菌进行快速富集筛选,并将所筛菌株进行复配研究,为构建脱氮除磷菌剂奠定基础.两段进水和提高注水比的运行方式能使反硝化聚磷菌在反应器中迅速成为优势菌.实验分离得到效果较好的反硝...     

东北地区城市污水厂运营状况与稳定运行对策

为进一步推进东北地区水污染防治工作,确保松花江及辽河流域水环境安全,促进东北地区经济、社会和环境协调发展,对辽宁、吉林及黑龙江3省32家典型城市污水处理厂的运营现状进行调查.结果显示,污水厂普遍存在着科学运营管理水平不高、污水回用率低、污泥处理处置不当等突出问题.今后,在技术及管理层面上,应改进运营模式、完善排水体制、...     

反硝化抑制硫酸盐还原菌活性机理及应用

根据目前油田杀灭硫酸盐还原菌的状况,提出反硝化抑制硫酸盐还原菌活性的设想.综述了反硝化抑制硫酸盐还原菌活性的机理,及其在国外油田污水处理中工程应用的效果、影响因素和存在的不足.提出在机理研究中,加强蛋白组学和环境基因组学方面的研究,特别是投加抑制物质如硝酸盐、反硝化细菌等对硫酸盐还原菌本身的基因和蛋白表达的影响,代谢途径的抑制研究,加强微生物分子生态学方法在理论研究和工程实践中的应用.同时对该机理在我国大庆油田的应用提出一些研究思路.     

Two-step fermentation process and the corresponding study on its enzymology characteristics

Strain HIT-3,which has good performances in cellulose degradation,was isolated from the campus soil. Based on the identification of conservative sequences 16S rDNA and the analysis of physiological-biochemical characteristics,HIT-3 was identified as Achromobacter xylosoxidans. Denitrificans. A two-step fermentation process was conducted by adopting compound-bioflocculant-producing flora constructed by cellulose-degrading bacterium HIT-3 and flocculating bacterium F2. The cellulose degradation metabolites of HIT-3 was taken as substrates by flocculating bacterium F2,by which excellent compound bio-flocculant was obtained. In addition,the enzymology characteristics of HIT-3 were investigated when cultured in cellulose media,which utilized CMC-Na as its sole carbon. The results show that HIT-3 achieves a climax of 67.6 U/mL of enzyme production after incubation for 6 d,and the organic carbons produced are sufficient as the substrates required by the fermentation of flocculating bacterium F2(flocculating efficiency of 85.6%),which makes it feasible to reuse bioenergy.