两株高效苯酚降解菌的筛选、鉴定及生物强化-DTRO组合工艺初步验证

【目的】从煤化工废水中分离、筛选苯酚高效降解微生物,初步考察微生物与DTRO技术联用,构建含酚废水生物强化处理工艺的可行性。【方法】采用苯酚浓度梯度培养基对苯酚降解微生物进行分离和筛选;根据菌体形态电子显微镜观察、菌株生理生化特性考察和16S r RNA基因系统发育树构建,对菌株进行初步生物学鉴定;将筛选出的高效苯酚降解菌制备成相应的菌剂与碟管式反渗透(DTRO)技术组合形成"生物强化-DTRO"工艺,并试用于含酚废水的处理。【结果】共获得7株纯化细菌,其中Phe-03和Phe-05为高效苯酚降解菌;该2株菌均可以苯酚为唯一碳源生长。经鉴定Phe-03为壤霉菌属(Agromyces)菌株;Phe-05为棒杆菌属(Corynebacterium)菌株。到目前为止,壤霉菌属(Agromyces)菌株降解苯酚尚未见报道。在初始苯酚浓度达到1 300 mg/L条件下,Phe-03和Phe-05菌株44 h内对苯酚降解率均达到70%以上;76 h后苯酚降解率均超过90%。组合形成的"生物强化-DTRO"工艺不仅可以有效去除废水中的酚类化合物,而且还能减少反渗透膜污染,以及增加膜的通透性。【结论】研究表明微生物技术可与DTRO技术联用,构建含酚废水生物强化处理工艺,可为含酚废水处理技术研究提供一种选择思路。     

一株苯酚降解菌的鉴定及其降解特性

【目的】鉴定从某化工厂附近土样中分离到的一株耐高浓度苯酚的菌株T10,通过优化菌株的培养条件提高菌株对苯酚的降解率。【方法】根据菌株的形态、生理生化鉴定及16S rDNA测序分析确定其种属,以液体摇瓶培养菌株T10对苯酚的降解率为指标,对菌株的生长条件进行优化。【结果】菌株T10属恶臭假单胞菌(Pseudomonas putida)。添加葡萄糖、蛋白胨能有效缩短T10菌的生长周期,并使苯酚的降解率提高1.7倍。在菌体初始接种浓度为10%、温度为30°C、转速为180 r/min条件下,对初始苯酚浓度、pH和装液量的响应面优化结果如下:初始苯酚浓度3 000 mg/L、pH 7.5和装液量80 mL/250 mL,苯酚去除率最高可达到87.56%。【结论】T10菌能够耐受较高浓度的含酚废水,并且对苯酚有较强的降解能力,为下一步利用生物法处理含酚废水提供科学依据。     

一株高效丙烯腈降解细菌Rhodococus rhodochrous BX2的丙烯腈降解条件优化

【目的】以丙烯腈为目标污染物,利用实验室已筛选获得的一株高效腈降解菌Rhodococus rhodochrous BX2,研究其对丙烯腈的降解特性,优化降解条件以提高菌株对丙烯腈的降解能力。【方法】通过单因素试验和响应面分析相结合的方法优化Rhodococus rhodochrous BX2对丙烯腈的降解条件。考察外加碳、氮源对BX2的生长及丙烯腈降解的影响,并确定其在丙烯腈合成废水中对丙烯腈的处理效果。【结果】菌株BX2优化后的最佳降解条件为:底物浓度403.51 mg/L、p H 7.44、温度34.46°C,在此条件下丙烯腈的降解率为95.1%。外加碳源为葡萄糖,或外加氮源为氯化铵对菌株生长及丙烯腈降解有明显的促进作用。菌株Rhodococus rhodochrous BX2能够高效降解合成废水中的丙烯腈,在30 h时其丙烯腈降解率可达89.4%。【结论】降解条件优化以及外源物质的添加强化了菌株对丙烯腈合成废水的处理效果,为生物法处理丙烯腈废水新方法的开发提供技术支持。     

苯酚降解菌红球菌(Rhodococcus sp.) P1的鉴定及其在焦化废水中的应用

摘要:【目的】酚类物质的去除是焦化废水处理的关键问题,目的是从焦化废水中分离高效的苯酚降解细菌。【方法】以苯酚为唯一碳源筛选纯化降解苯酚细菌,菌株鉴定采用菌落形态和16S rRNA 序列分析方法,并研究其苯酚降解特性和在焦化废水中的除酚作用。【结果】菌落形态和16S rRNA序列比对分析表明分离的P1菌株为红球菌属(Rhodococcus sp.)细菌;其耐酚浓度高达1400 mg/L,苯酚降解的最适条件为32℃－42℃、pH 7.0和0－4%盐;苯酚降解动力学曲线符合Haldane动力学模型,qmax=0.517/h,Ks=77.487 mg/L,Ki=709.965 mg/L;不同重金属对红球菌P1菌株的苯酚降解抑制作用不同,Zn2+、Mn2+和低浓度的Pb2+对菌株降酚没有影响,Cu2+、Ni2+、Cd2+均抑制菌株对酚的降解;红球菌P1菌株2d内可完全降解1/3焦化原水中的279.9 mg/L酚类物质。【结论】P1菌株是1株高效的苯酚降解菌,具有生物处理焦化废水酚类物质的潜力。     

高效苯酚降解菌的选育及降酚特性

以苯酚为惟一碳源,采用逐量分批驯化筛选法筛选高效降酚菌并研究其降酚特性.结果筛选出1株可降解高浓度苯酚的菌株,经鉴定为假单孢菌属(Pityrosporum sp.).该菌株可降解 1 800 mg/L的高浓度苯酚,其降酚性能受许多因素影响:降解苯酚的最适环境条件为温度 30 ℃,pH 6～7,振荡速率大于 150 r/min.     

一株耐盐菌Halomonas sp. A20的分离及降解糖精钠废水的特性

【背景】糖精钠废水是一种难处理的高盐有机工业废水。【目的】为了提高糖精钠废水的生物降解效果,需要研究糖精钠废水降解菌的特性。【方法】采用纯培养技术从处理糖精钠废水的多级生物接触氧化系统内的活性污泥中分离筛选糖精钠废水降解菌,对分离菌株的形态特征、生理生化特性和16S rRNA基因序列进行分析,利用单因素实验和响应面法考察分离菌株降解糖精钠废水的最佳条件。【结果】筛选获得一株糖精钠废水降解菌A20,归属于盐单胞菌属(Halomonas),当糖精钠废水的盐分为5%,菌接种量为15%,pH值为8.0,温度为30°C时,菌株A20对糖精钠废水中的化学需氧量(chemical oxygen demand,CODcr)去除率在60%以上;通过响应面法优化,菌株A20降解糖精钠废水的最佳条件为：pH 8.0,温度为30.3°C,接种量为14.1%,其CODcr去除率为65.4%。【结论】分离到一株能高效降解糖精钠废水中有机物的耐盐菌Halomonas sp. A20,可为高盐、高浓度糖精钠废水的处理提供优良的微生物菌种资源。     

3-苯氧基苯甲酸降解菌Sphingomonas sp. SC-1降解苯酚环境条件及其降解中间产物的研究

【目的】探究高效降解3-苯氧基苯甲酸(3-Phenoxybenzoic acid,3-PBA)的鞘氨醇单胞菌(Sphingomonas sp.) SC-1对苯酚的降解特性。【方法】采用HPLC测定微生物降解体系中苯酚残留量,考察环境条件对菌株SC-1降解苯酚的影响;分析不同培养时间苯酚降解体系混合样品的HPLC谱图,确定其降解中间产物。【结果】菌株SC-1能在基础盐培养基中以苯酚为唯一碳源和能源生长,在初始pH 7.0、30 °C条件下,24 h可完全降解100 mg/L苯酚;Cu2+、Ba2+、Mn2+等对其降解苯酚有不同程度的抑制作用;HPLC谱图分析,初步确定邻苯二酚是菌株SC-1降解苯酚的中间产物,且该菌株可在48 h内完全降解100 mg/L邻苯二酚。【结论】菌株SC-1对苯酚及邻苯二酚均有较强的降解能力,为完善3-PBA的降解途径及污染3-PBA或含酚废水或含酚农药残留的降解提供了数据参考。     

好氧反硝化细菌SY-D-22的分离、优化及脱氮机理

【背景】在处理含硝酸盐氮的废水中,常见微生物不能同时高效去除硝酸盐氮和总氮,导致处理废水时往往使用多种微生物复合菌剂或者使用复杂的工艺。【目的】高效、安全地去除水中的硝酸盐氮和总氮。方法】富集筛选出一株新型高效好氧反硝化细菌,对其进行16S rRNA基因鉴定。利用响应面法对其影响脱氮因素进行优化并探索其最佳脱氮条件。研究其对含硝酸盐氮废水的反硝化能力及脱氮特性。【结果】从活性污泥中筛选获得一株新型高效好氧反硝化细菌SY-D-22,经鉴定为葡萄球菌属(Staphylococcus)。响应面法优化其最佳反硝化条件为：pH 8.18,C/N为13.39,温度31.43°C,摇床转速130 r/min。当以最佳碳源柠檬酸钠为唯一碳源时,对于100 mg/L浓度的NO₃^--N去除率可达100%,同时对于总氮(total nitrogen,TN)的去除率为95.34%,具有高效脱氮能力。【结论】从活性污泥中筛选出一株新型好氧反硝化细菌Staphylococcus SY-D-22,通过响应面法条件优化,菌株的硝酸盐氮去除率达到100.00%,总氮去除率达到...     

高效苯酚降解菌细胞固定化方法与条件的研究

含酚废水是一种难降解有机废水,对环境污染非常严重。目前常利用细菌处理含酚废水。但利用细菌处理含酚废水存在一些缺点,为此将1株高效苯酚降解菌进行细胞固定化。采用正交实验设计方法确定了该菌株固定化的最佳条件,并且考察了该固定化细胞降解苯酚的最佳条件。实验表明:该菌株的固定化细胞降解苯酚能力和耐受苯酚能力均大于游离细胞,经36 h可将1 800 mg/L苯酚降解完全。其降解苯酚的最适温度为30℃,最佳pH值为5~9。     

一组高效喹啉降解复合菌群的构建及其降解特性

【背景】喹啉是一种典型的含氮杂环污染物,广泛存在于焦化废水,具有致畸、致癌、致突变作用,易通过水体污染环境。微生物技术因其绿色高效的特点,被认为是喹啉废水污染最有前景的修复手段之一。【目的】筛选得到一组高效喹啉降解复合菌群,实现含喹啉废水的高效工业化处理。【方法】使用逐级递增驯化法从焦化废水厂污泥中筛选出一组高效喹啉降解复合菌群,结合形态学观察并通过酶活测定、底物广谱性研究,完成对该复合菌群的初探。然后将该复合菌群的培养pH、温度、转速、装液量、接菌量、不同浓度外加碳氮源进行单因素优化,结合优化结果以喹啉降解率为目标进行响应面优化,并通过降解动力学研究喹啉对复合菌群降解行为的影响。【结果】分离出可30 h降解1 500 mg/L喹啉的高效复合菌群,可以降解多种含氮杂环化合物;响应面优化结果表明,当pH、温度、转速分别为6.8、30 ℃、200 r/min时,降解率最高达66%;降解动力学分析发现,当喹啉浓度为1 154 mg/L时,比降解率最大高达60.0 mg/(L·h)。【结论】该复合菌群具有高效喹啉降解能力和底物降解广谱性,为微生物高效处理含喹啉废水的工业化处理提供了良好基础。     

焦化废水中4株苯酚高效降解菌的分离及鉴定

目的:从焦化废水中筛选苯酚高效降解菌并进行鉴定.方法:在100～1000 mg/L的苯酚为惟-碳源的无机盐培养基上分离出单菌落,测定各菌株的生长曲线以及对苯酚的降解效牢;利用 16S rDNA序列分析结合菌株的形态特征确定各菌株的分类地位.结果:筛选获得4株苯酚降解菌,均能够以苯酚为惟一碳源,在30℃、pH7.0、摇床转速130 r/min、2%的接种量条件下,24h内能将1 000mg/L的苯酚降解91%以上;4株菌可初步鉴定为芽孢杆菌属(ZL1)、产碱杆菌属(ZL2、ZL4)、沙雷氏菌属(ZL3).其中,从焦化废水中分离出高效降解苯酚的沙雷氏菌未见报道.结论:从焦化废水中获得4株苯酚高效降解细菌,对高浓度含酚废水的生物降解具有潜在的应用前景.     

Salt-tolerant phenol-degrading microorganisms isolated from Amazonian soil samples

Two phenol-degrading microorganisms were isolated from Amazonian rain forest soil samples after enrichment in the presence of phenol and a high salt concentration. The yeast Candida tropicalis and the bacterium Alcaligenes faecoalis were identified using several techniques, including staining, morphological observation and biochemical tests, fatty acid profiles and 16S/18S rRNA sequencing. Both isolates, A. faecalis and C. tropicalis, were used in phenol degradation assays, with Rhodococcus erythropolis as a reference phenol-degrading bacterium, and compared to microbial populations from wastewater samples collected from phenol-contaminated environments. C. tropicalis tolerated higher concentrations of phenol and salt (16 mM and 15%, respectively) than A. faecalis (12 mM and 5.6%). The yeast also tolerated a wider pH range (3-9) during phenol degradation than A. faecalis (pH 7-9). Phenol degradation was repressed in C. tropicalis by acetate and glucose, but not by lactate. Glucose and acetate had little effect, while lactate stimulated phenol degradation in A. faecalis. To our knowledge, these soils had never been contaminated with man-made phenolic compounds and this is the first report of phenol-degrading microorganisms from Amazonian forest soil samples. The results support the idea that natural uncontaminated environments contain sufficient genetic diversity to make them valid choices for the isolation of microorganisms useful in bioremediation.     

Biodegradation of Phenol: Mechanisms and Applications

Phenol, or hydroxybenzene, is both a synthetically and naturally produced aromatic compound. Microorganisms capable of degrading phenol are common and include both aerobes and anaerobes. Many aerobic phenol-degrading microorganisms have been isolated and the pathways for the aerobic degradation of phenol are now firmly established. The first steps include oxygenation of phenol by phenol hydroxylase enzymes to form catechol, followed by ring cleavage adjacent to or in between the two hydroxyl groups of catechol. Phenol hydroxylases ranging from simple flavoprotein monooxygenases to multicomponent hydroxylases, as well as the genes coding for these enzymes, have been described for a number of aerobic phenol-degrading microorganisms. Phenol can also be degraded in the absence of oxygen. Our knowledge of this process is less advanced than that of the aerobic process, and only a few anaerobic phenol-degrading bacteria have been isolated to date. Convincing evidence from both pure culture studies with the denitrifying organism Thauera aromatica K172 and with two Clostridium species, as well as from mixed culture studies, indicates that the first step in anaerobic phenol degradation is carboxylation in the para-position to form 4-hydroxybenzoate. Following para-carboxylation, thioesterification of 4-hydroxybenzoate to co-enzyme A allows subsequent ring reduction, hydration, and fission. Para-carboxylation appears to be involved in the anaerobic degradation of a number of aromatic compounds. Numerous practical applications exist for microbial phenol degradation. These include the exploitation of indigenous anaerobic phenol-degrading bacteria in the in situ bioremediation of creosote-contaminated subsurface environments, and the use of phenol as a co-substrate for indigenous aerobic phenol-degrading bacteria to enhance in situ biodegradation of chlorinated solvents.     

The effect of concentration of phenols on their batch methanogenesis

The biodegradability of phenol and six other phenolic compounds (o-, m-, and p-cresol, 2-, 3-, and 4-ethylphenol) was examined in batch methanogenic cultures. The effect of concentration of these alkyl phenols on the anaerobic biodegradation of phenol was also evaluated. The inoculum used in this study was cultivated in a continuous flow laboratory fermenter with phenol as the primary substrate. Phenol, at initial concentrations as high to 1400 mg/L was completely degraded to methane and carbondioxide after 350 hours incubation. Complete degradation of m- and p-cresol was also observed while the ethylphenols and o-cresol were not significantly degraded.At initial concentrations exceeding 600 mg/L, phenol inhibited the phenol-degrading microorganisms but not the methanogens. At about 600 mg/L, cresols reduced the rate of phenol degradation to 50% of that observed in a control culture containing only 200 mg/L phenol. Ethylphenols were more inhibitory than cresols. Phenol degrading microorganisms were more susceptible to inhibition by cresols and ethylphenols than were the methanogens. The inhibitory effects of the three isomers of cresol and ethylphenol did not vary with the isomer but rather with the substituted functional group.     

木质素降解菌BYL-7的筛选及降解条件优化

【背景】微生物降解木质素因其具有降解效率高和环保等特点而备受关注。【目的】筛选高效木质素降解真菌,并对其降解条件进行优化。【方法】通过愈创木酚-马铃薯葡萄糖琼脂(potato dextrose agar,PDA)和苯胺蓝平板法筛选高效木质素降解菌株,利用单因素筛选及响应面试验对培养条件进行优化。【结果】筛选到一株高效木质素降解菌BYL-7,经形态和多序列分析初步确定为Trametes versicolor。单因素试验证明初始pH、温度和接种量为降解木质素显著影响因子,响应面试验确定降解木质素最优条件为：初始pH 6.7,温度25 °C,接种量8%。在此条件下,碱性木质素降解率为36.5%,比未优化前提高54.0%;水稻秸秆木质素、半纤维素和纤维素降解率分别为32.8%、21.5%、13.2%,其中木质素降解率比未优化前提高36.1%;漆酶活性在第6天达到峰值120.0 U/L,比未优化前提高25.0%;木质素过氧化物酶活性在第6天达到峰值1 343.8 U/L,比未优化前提高36.0%;锰过氧化物酶活性在第5天达到峰值463.8 U/L,比未优化前提高31.7%。【结论】研究结果为木质素的降解提供了良好的菌种资源,同时也为后续木质素的研究积累了相关数据。     

Isolation,selection, and biological characterization research of highly effective electricigens from MFCs for phenol degradation

The microbial fuel cells (MFCs) are recognized to be highly effective for the biodegradation of phenol. For isolating the phenol-degrading bacteria, the sample containing 500 mg/L phenol was collected from the MFCs. The strain (WL027) was identified basing on the 16S rRNA gene analysis and phylogenetic analysis as Bacillus cereus. The effects of pH, temperature, concentrations of phenol, heavy metal ions, and salt on the growth of strain as well as the degradation of phenol have been carefully studied. The WL027-strain exhibited favorable tolerance for the metal cations including Cr²⁺, Co²⁺, Pb²⁺, and Cu²⁺ with the concentration of 0.2 mg/L and NaCl solution with a high concentration of 30 g/L. In 41 h, 86.44% of 500 mg/L phenol has been degraded at the initial pH at 6 and the temperature of 30 °C. The strain was highly active electrogenesis bacteria and the coulombic efficiency reached 64.25%, which showed significant advantage on the efficient energy conversion. Therefore, due to the highly efficient degradation of phenol, WL027-strain could be used in the treatment of phenol-containing wastewater.     

一株耐高盐热带假丝酵母菌降解苯酚的研究

从含酚废水处理池污泥中驯化分离得到一株能以苯酚为唯一碳源的菌株FD-1。经18SrDNA和ITS序列的BLAST比对及系统发育分析,鉴定FD-1为热带假丝酵母(Candida tropicalis)的近缘种。FD-1对苯酚的降解能力较强,能够完全降解浓度为1 000mg·L-1的苯酚溶液。初步确定了FD-1在降解苯酚溶液时的最适温度为30~35℃,pH为6.0~7.0,并且通过探讨加入无机盐、培养基原料以及改变接种量三个因素对苯酚降解的影响,其耐受盐的浓度可达5%,对实践中应用微生物降解含酚废水具有积极的意义。     

一株大蒜素降解菌的分离与鉴定

【目的】解决大蒜废水难以生化处理的问题,筛选能够降解大蒜素的细菌,并对其生化特性进行分析。【方法】通过16S r RNA基因测序,对大蒜废水沉积物进行细菌多样性分析,发现其中有多种大蒜素耐受菌;通过富集培养与划线分离大蒜素降解菌,并进一步分析其最适生长和大蒜素降解条件。【结果】得到一株大蒜素降解菌(JX6-2),能够以大蒜素为唯一碳源生长(50-300 mg/L),将大蒜素彻底降解。其最适生长温度和降解大蒜素温度均为35°C,最适pH值在中性左右,添加葡萄糖对大蒜素降解没有明显影响。【结论】分离得到了一株大蒜素降解菌,分析了其生长和降解特性,为生化方法处理大蒜素废水提供了新菌种。