真菌和细菌对染料吸附脱色的高效共培养体系研究

在含有真菌G 1培养液中加入染料厂污水排放口的污泥样品 ,从发生快速脱色降解染料的混合培养液中分离出 2株染料脱色细菌L_1和L_2 ,经API鉴定系统鉴定 ,确定菌株L_1为Enterobactersp .,菌株L_2为Peudomonassp .。研究比较了单一和不同组合混合的真菌G_1菌株 (Penicilliumsp .)、细菌L_1菌株 (Enterobactersp .)和L_2菌株 (Pseu domonassp .)对偶氮染料红M - 3BE(C .I .ReactiveRed 2 41)和蒽醌染料艳蓝KN -R(C .1.ReactiveBlue 19)的去除情况 ,发现G - 1真菌和 2种细菌组合的共培养体系对 5 0mg/L红M - 3BE和艳蓝KN -R处理 5h去除率达 10 0 %和 97.9% ,并且是以脱色降解作用为主 ,建立了染料脱色降解菌的最佳组合 ;进一步测定了此最佳共培养体系对另外 13种不同结构染料的脱色降解 ,结果表明 ,除对蒽醌染料R - 478脱色降解较差外 ,对其他染料均可在lh— 3d被完全脱色降解 ,表现出脱色降解染料的广谱性 ;向培养 4d的共培养体系中依次加入 8种染料 ,菌体可对染料连续脱色 ,维持脱色能力达 8d左右     

与环境污染物转化相关的细菌厌氧呼吸研究动态

基于细菌呼吸理论为基础的环境有毒物质降解为环境污染治理提供了新的策略和方法,是近年来研究的热点问题.细菌呼吸是自然界中一个最基本、最重要的生物代谢过程,具有很大的灵活性和多样性,且与生态环境密切相关.在厌氧条件下,细菌利用环境中多种有毒物质作为呼吸链末端电子受体进行厌氧呼吸,在有毒物质被还原甚至降解的同时实现电子在呼吸链上的传递,形成跨膜的质子浓度电势梯度,进而转化为其生长代谢所需的能量.细菌以环境有毒物质为电子受体的厌氧呼吸不断被发现,这对于深入理解细菌呼吸的本质具有重要的理论意义,同时对于有毒物质的降解及元素的生物地球化学循环具重要的环境学意义,对于提高对地球表面有毒物质污染生物修复策略的认识具有重要的现实意义.图1表1参45     

理化环境条件对青霉菌和细菌吸附脱色染料的影响

在筛选到的染料吸附脱色真菌和细菌的基础上 ,测定了温度和pH值对青霉G 1吸附和与细菌共培养脱色降解染料的影响。结果表明 ,16— 36℃下青霉G 1对艳紫KN B(C .I.Re .Vi.2 2 )和黄M 3RE(C .I.Re .Ye .14 5 )的吸附去除能力受温度影响不大 ,吸附 5h去除率在 97.1%— 98.7% ,而染料的脱色时间受温度影响较大 ,2 8— 36℃下脱色速度快 .青霉G 1对pH 3— 11染料水中染料的吸附去除率高 ,达 94 .9%— 97.8% ,对pH 13的吸附去除率低 ,仅为 5 5 .4 %和 5 6 .2 % ,从pH 5—13染料水中吸附染料的菌丝在与细菌共培养 5— 2 6h即完成了对染料的脱色 ,脱色速度较快     

生物法修复铬污染土壤的研究

用生物修复技术来处理受铬污染的土壤，利用自然界中微生物，通过生物还原反应，将Cr(Ⅵ)还原成三价铬。先是通过土壤与合铬的培养基一起培养，筛选出5种能还原Cr(Ⅵ)的菌种，鉴定其菌属，并试验用这些菌种处理铬污染土壤的效果。同时还考虑了pH值对处理效果的影响。试验结果表明：筛选出5种菌种可以还原Cr(Ⅵ)；混菌处理效果最好，最高可达到100％；混菌处理污染土壤的适宜pH值范围为6．0—8．0。     

新型淡水发光菌(Vibrio qinghaiensis sp.——Q67)应用于环境样品毒性测试的初步研究

研究表明，新型淡水发光菌作为环境样品毒性检验的指标生物具有快速简便的优点。对重金属物毒性检验比以往Ｔ３发光菌具有更高的灵敏度，对鱼体进行的感染实验未发现明显病理改变。     

Degradation of 2,6-di-tert-butylphenol by an isolated high-efficiency bacterium strain

An aerobic bacterium strain, F-3-4, capable of effectively degrading 2,6-di-tert-butylphenol(2,6-DTBP), was isolated and screened out from an acrylic fiber wastewater and the biofilm in the wastewater treatment facilities. This strain was identified as Alcaligenes sp. through morphological, physiological and biochemical examinations. After cultivation, the strain was enhanced by 26.3% in its degradation capacity for 2,6-DTBP. Results indicated that the strain was able to utilize 2,6-DTBP, lysine, lactamine, citrate, n-utenedioic acid and malic acid as the sole carbon and energy source, alkalinize acetamide, asparagine, L-histidine, acetate, citrate and propionate,but failed to utilize glucose, D-fructose, D-seminose, D-xylose, sedne and phenylalanine as the sole carbon and energy source. The optimal growth conditions were determined to be: temperature 37℃, pH 7.0, inoculum size 0.1% and shaker rotary speed 250 r/min. Under the optimal conditions, the degradation kinetics of 2,6-DTBP with an initial concentration of 100 mg/L was studied. Results indicated that 62.4% of 2,6-DTBP was removed after 11 d. The degradation kinetics could be expressed by Eckenfelder equation with a half life of 9.38 d. In addition, the initial concentration of 2,6-DTBP played an important role on the degradation ability of the strain. The maximum initial concentration of 2,6-DTBP was determined to be 200 mg/L. Above this level, the strain was overloaded and exhibited significant inhibition.     

应用红外方法探讨耐镉菌株高积累Cd2+的机理

从安徽某冶炼厂污染土壤中分离出一株能耐高浓度镉的菌株(J5),经初步鉴定为假单胞菌属(Pseudomonas sp.).该菌株在液体培养基中耐受40 mmol·L-1 CdSO4,在固体培养基上耐受75mmol·L-1 CdSO4.培养基中Cd2+、Zn2+、Pb2+、Cu2+浓度分别为100 mg·L-1和Mn2+浓度为275mg·L-1时,菌株生长正常.在重金属Cu2+、Pb2+、Zn2+、Mn2+存在时,采用红外光谱与原子吸收光谱分析菌株对Cd2+的积累,结果表明,在低浓度Cd2+溶液中菌株细胞对Cd2+的积累,主要靠细胞壁上-NH2与Cd2+配位结合;在高浓度Cd2+溶液中,细胞壁上-NH2、-OH、-COOH、-PO43-、-M-O(O-M-O)基团吸附Cd2+的能力显著.Mn2+可以增加细胞壁上有效官能团活性,提高Cd2+积累率;但当有Zn2+、Pb2+、Cu2+重金属离子共存时,即使有Mn2+存在,菌体对Cd2+吸附积累能力未见提高.     

Quantification of multi-antibiotic resistant opportunistic pathogenic bacteria in bioaerosols in and around a pharmaceutical wastewater treatment plant

Pharmaceutical wastewater treatment plants(WWTPs) are thought to be a "seedbed" and reservoirs for multi-antibiotic resistant pathogenic bacteria which can be transmitted to the air environment through aeration. We quantified airborne multi-antibiotic resistance in a full-scale plant to treat antibiotics-producing wastewater by collecting bioaerosol samples from December2014 to July 2015. Gram-negative opportunistic pathogenic bacteria(GNOPB) were isolated, and antibiotic susceptibility tests against 18 commonly used antibiotics, including 11 β-lactam antibiotics, 3 aminoglycosides, 2 fluoroquinolones, 1 furan and 1 sulfonamide, were conducted.More than 45% of airborne bacteria isolated from the pharmaceutical WWTP were resistant to three or more antibiotics, and some opportunistic pathogenic strains were resistant to 16 antibiotics, whereas 45.3% and 50.3% of the strains isolated from residential community and municipal WWTP showed resistance to three or more antibiotics. The calculation of the multiple antibiotic resistance(MAR) index demonstrated that the air environment in the pharmaceutical WWTP was highly impacted by antibiotic resistance, while the residential community and municipal WWTP was less impacted by antibiotic resistance. In addition, we determined that the dominant genera of opportunistic pathogenic bacteria isolated from all bioaerosol samples were Acinetobacter, Alcaligenes, Citrobacter, Enterobacter, Escherichia, Klebsiella, Pantoea, Pseudomonas and Sphingomonas. Collectively, these results indicate the proliferations and spread of antibiotic resistance through bioaerosols in WWTP treating cephalosporin-producing wastewater, which imposed a potential health risk for the staff and residents in the neighborhood, calling for administrative measures to minimize the air-transmission hazard.     

Characterization of the effective cellulose degrading strain CTL-6

An efficient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of effective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose (80.9% weight loss after 9 days of culture). The highest efficiency value of the endocellulase (CMCase activity) was 0.404 μtmol/(min-mL), cellulose degradation efficiency by CTL-6 was remarkably high at 50-65°C with the highest degradation efficiency observed at 60°C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, celiobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C.therrnocellum is unable to do so.     

甲胺磷降解菌的分离与降解特性研究

从长期受甲胺磷农药污染的土壤中采集土样,经过富集培养,稀释倒平板后划线分离得到3个菌株,分别编号为J-1,J-2,J-3菌株。将分离到的3个菌株接种到富集培养基中培养后,利用钼锑抗分光光度法测定磷含量变化,明显可以看出J-3菌株具有较高的降解能力,因此选择J-3菌株作为下一步研究的对象。经形态学和生理生化指标初步鉴定J-3菌株为假单胞菌。J-3菌株能在没有外加碳氮源的情况下以甲胺磷作为唯一的碳源和氮源生长。另外,确定J-3菌株降解甲胺磷的最适温度为37℃,最适pH为7.0,外加碳氮源分别为葡萄糖和蛋白胨,最适装液量和接种量分别为100,250mL和8%等降解特性。