不适宜生长条件对混茵降解苯胺的影响

分别从台州和衢州某化工厂的好氧池中分离筛选得到2株苯胺降解菌TZl和JH1,经16SrDNA测序鉴定为Comamonassp．TZ1和Pseudomonassp．JH1,均具有较强的苯胺降解能力,培养24h后,可使初始浓度为800mg／L的苯胺去除率达到96．4％～98．4％。在此基础上,按体积比l：1将2株菌液进行混合构建了混合菌体系,进而对比考察了苯胺初始浓度、pH、盐度和重金属等环境因子对单一菌和混合菌生长量及降解苯胺效果的影响,重点探讨混合菌对不适宜生长环境的适应性及其对苯胺的降解特性。通过单一菌和混合菌对比实验发现,在适宜苯胺初始浓度、pH和盐度条件下,混合菌的生长量略高于单一菌;在不适宜生长的高浓度苯胺、pH和盐度条件下,混合菌也表现出了更强的适应性和苯胺矿化能力。Zn2＋和Cr6＋耐受实验则表明,对于Cr6＋混合菌表现出了更强的耐受能力,而对于zn2＋并没有表现出更强的耐受能力。     

优势菌种浸取电解锰渣中锰的影响因素研究

采用电解锰废渣中分离出的一种锰抗性强的微生物Fusarium sp.浸取电解锰渣中的锰。研究了不同矿浆浓度、微生物生长活动、锰渣和培养基等对锰浸取效率的影响。结果表明,接种体积比为2%（v/v）时,矿浆浓度（m/v）对锰浸取效率影响显著,矿浆浓度过低（〈2%）或者过高（〉10%）对锰浸取效率都有不利影响。矿浆浓度为10%时锰浸取效率最高,达80%以上;微生物的生长活动对浸取过程有显著的影响;而锰渣的存在则能在一定程度上影响溶液的pH,进而影响锰浸取效率;培养基对锰浸取效率的贡献达50%左右。     

UASB反应器对晚期渗滤液的碳氮协同削减效应

为了强化UASB反应器对厌氧+好氧反应器末端出水的生物处理过程,采用厌氧+好氧反应器+UASB反应器工艺,通过生物处理方法实现了难降解有机物与氮的协同削减.结果表明:①通过控制UASB反应器中ρ（NO_x--N）,优化微环境中最佳ORP范围,当ORP为（-300±10）mV时,ρ（COD_Cr）（此时主要以胡敏酸和富里酸等难降解的腐殖性有机物为主）由313.00 mg/L降至106.00 mg/L,ρ（TN）由139.60 mg/L降至60.30 mg/L,去除率分别达66.13%、56.81%.②傅里叶红外光谱分析结果显示,出水中含羧基、羟基、醌基、酰胺、苯环取代基等相关官能团的有机物减少,含脂肪族官能团的有机物增多.③16S rRNA结果显示,厌氧+好氧反应器+UASB反应器中的优势菌属分别为VadinHA17、Clostridium（梭菌属）、Anaerolineaceae（厌氧绳菌属）、Denitratisoma,其丰度占比分别为3.29%、35.17%、8.60%、2.84%.VadinHA17通过降解UASB反应器中的多种复杂有机物,为反硝化过程提供碳源;Clostridium利用UASB反应器中丰富的硝酸盐激活Clostridium胞外氧化酶,强化Clostridium对难降解复杂有机物的降解能力,将自身的胞内电子通过细胞膜上的细胞色素传递到胞外电子受体上,使NO_x--N得到电子还原为氨,降低氮含量;Anaerolineaceae与Denitratisoma则分别作用于UASB反应器的厌氧消化过程及生物脱氮过程.研究显示,UASB反应器中由于VadinHA17、Clostridium、Anaerolineaceae与Denitratisoma的作用,COD_Cr和TN去除率分别为66.13%、56.81%,实现了晚期渗滤液中难降解有机物与TN的协同削减.      

生物炭固定耐镉菌群对Cd2+的吸附及作用机制

从广西某硫化尾矿中分离出一耐镉菌群,将其固定在生物炭上制成固定化菌剂.同时,探究了生物炭种类、添加量、溶液pH、Cd²⁺初始浓度对固定化菌剂吸附Cd²⁺性能的影响,并结合吸附动力学、吸附等温线、16S rDNA、SEM、FTIR、XPS等分析测试手段研究了固定化菌剂对Cd²⁺的吸附过程和作用机制.结果表明,竹生物炭制备的固定化菌剂(ZBCM)对Cd²⁺的吸附效果最佳,在Cd²⁺浓度为20 mg·L^-1、pH=6、生物炭投加量为3 g·L^-1的条件下,ZBCM对Cd²⁺的吸附率达89.49%,较生物炭和单菌群的吸附率分别提高了54.6%和53.51%.从属水平上看,菌群主要由梭状芽孢杆菌、毛梭菌和产己酸菌构成,ZBCM吸附Cd²⁺后优势菌变为副梭菌、毛梭菌和贪铜菌,贪铜菌丰度的增长增强了ZBCM对Cd²⁺的络合和生物积累作用.ZBCM对Cd²⁺的吸附...     

草甘膦对同源假单胞基因工程菌代谢活性的影响

基于微量热法,研究两株基因缺失型斯氏假单胞杆菌对草甘膦的耐受毒性和降解作用,结果表明:草甘膦可以作为菌株的能量来源;草甘膦对P.stutzeri WM 581和P.stutzeri WM 567的半抑制浓度分别为47.47,43.26mg/L.两菌株对草甘膦均有较快的降解速率,其降解的半衰期约为9~17h,而草甘膦作为2类菌株生长过程中可以代谢的营养物质,其作为唯一碳源时的降解率(64%)要高于作为磷源时的降解率(43%).pH值与盐度对两菌株的生长有较大影响,草甘膦降解的较佳条件为:pH值为6,盐度低于0.5g/L.     

生物滴滤塔中两种优势菌种对高浓度甲苯废气净化对比实验

以陶粒为填料,用分别负载2种单一降解甲苯的优势菌种S1、S2的生物滴滤塔净化高浓度甲苯废气的性能进行对比实验研究,实验结果表明:虽然2种优势菌种同为芽孢杆菌,但是菌种S1在降解能力以及停用后恢复等各项指标中均明显高于菌种S2。当甲苯进口浓度低于5.81 mg/L时,S1菌种的去除率始终保持在90%以上,最高的进口浓度达到10.00 mg/L时,甲苯的去除率也可以达到59.78%。对于S2菌种而言,当最高进口浓度达到5.72 mg/L,甲苯的降解率仅可以达到65.65%。两个滴滤塔在停用后恢复运行时,菌种S1可以在极短的时间内恢复,菌种S2则是规律性的在恢复初期出现降解率最低点,且甲苯降解效率只能恢复到70%~80%。     

Differential degradation of crude oil （Bonny Light） by four Pseudomonas strains

Four hydrocarbon degraders isolated from enriched oil- and asphalt-contaminated soils in Lagos, Nigeria, were tested for their petroleum degradation potentials. All the isolates were identified as species of Pseudomonas. Pseudomonas putida P11 demonstrated a strong ability to degrade kerosene, gasoline, diesel, engine oil and crude oil while P. aeruginosa BB3 exhibited fair degradative ability on crude oil, gasoline, engine oil, anthracene and pyrene but weak on kerosene, diesel and dibenzothiophene. Pseudomonas putida WL2 and P. aeruginosa MVL1 grew on crude oil and all its cuts tested with the latter possessing similar polycyclic aromatic potentials as P11. All the strains grew logarithmically with 1–2 orders of magnitude and with generation time ranging significantly between 3.07 and 8.55 d at 0.05 level of confidence. Strains WL2 and MVL1 utilized the oil substrate best with more than 70% in 6 d experimental period, whereas the same feat was achieved by P11 in 12 d period. BB3 on the other hand degraded only 46% within 6 d. Interestingly, data obtained from gas chromatographic analysis of oil recovered from the culture fluids of MVL1 confirmed near-disappearance of major peaks (including aliphatics and aromatics) in the hydrocarbon mixture.     

报废发射药降解菌种选育及降解特性

通过驯化富集培养,从长期受发射药污染的土壤中分离筛选出能以发射药为唯一碳源并具有较高降解能力的微生物混合菌群,混合菌群对发射药样品COD去除率最高可达75.6%。经进一步分离纯化,获得了5株优势菌。实验表明混合菌群的降解能力优于各单一菌种,应以混合菌群为目标菌种。混合菌群最佳降解温度为30～35℃,最佳pH值为7.0。...     

Selection of microalgae for high CO2 fixation efficiency and lipid accumulation from ten Chlorella strains using municipal wastewater

As significant differences in cellular physiology, metabolic potential and genetics occur among strains with morphological similarity, the screening of appropriate microalgae species for effective CO₂ fixation and biodiesel production is extremely critical. In this study, ten strains of Chlorella were cultivated in municipal wastewater influent (MWI) and their tolerance for MWI, CO₂ fixation efficiency and lipid productivity were assessed. The results showed that the biomass concentrations of four strains (Chlorella vulgaris, Chlorella 64.01, Chlorella regularis var. minima and Chlorella sp.) were significantly higher than other strains. When the cultivation systems were aerated with 10% CO₂, Chlorella sp. showed the highest CO₂ fixation efficiency (35.51%), while the highest lipid accumulation (58.48%) was observed with C. vulgaris. Scanning electron microscopy images revealed that the cells of both Chlorella sp. and C. vulgaris kept their normal morphologies after 15 day batch culture. These findings indicated that Chlorella sp. and C. vulgaris have fairly good tolerance for MWI, and moreover, Chlorella sp. was appropriate for CO₂ fixation while C. vulgaris represented the highest potential for producing biodiesel.     

微生物降解土壤中农药残留的研究进展

研究土壤环境中农药的微生物降解是当今国际环境修复科学技术前沿领域的重要课题.从降解农药的微生物种类、降解农药的途径及机理、基因工程菌的构建等方面综述了近年来的研究进展,并提出了微生物降解农药研究领域的发展趋势和有待进一步解决的一些突出问题.