降解SO2功能菌的16S rRAN基因测序及降解特性

用低浓度SO2诱导驯化方法获得高效脱硫菌群,并用分离培养与16S rRNA基因测序技术相结合的方法鉴定菌群种属,分析驯化过程中种群结构的动态变化,同时研究分离纯菌种的脱硫性能。结果表明,从诱导驯化7 d和14 d菌液中分别分离出23株菌和22株菌,16S rRNA序列分析发现这些菌归属于13个种,其中有6个种(Rhodococcus erythropolis、Pseudomonas putida、Microbacterium oxydans、Sphingomonas koreensis、Acinetobacter junii、Acinetobacter johnsonii)对SO2-3有较强的降解能力,并在持续驯化过程中稳定的生长传代,降解产物以硫酸根为主,还有极少量的单质硫。与含混合菌的驯化菌液降解SO2-3的能力相比,单一脱硫菌的脱硫性能较弱。脱硫功能菌株及其基本特性的研究为微生物处理SO2烟气提供了丰富的菌源信息和理论基础。     

稠油降解微生物的筛选鉴定及其降解特性

从二连油田原油和油层水中筛选驯化出3株能够降解稠油的细菌DS1、DS2和DS3,通过16S rRNA基因序列比对发现DS1、DS2和DS3分别与溶血不动杆菌(Acinetobacter haemolyticus)、鹑鸡肠球菌(Enterococcus gallinarum)和耳炎短杆菌(Brevibacterium otitidis)相似度最高,分别为99%、99%和98%。研究结果表明,DS1对温度和pH有较强耐受性,DS3对盐度的适应性较好,2株菌最适的降解条件为温度35~40℃、盐度2%~5%(W/V)、pH为7~10。在5%的原油浓度下,复合菌对原油的30 d降解率达89.2%。经GC-MS分析,微生物降解作用后,除C29其他烃类几乎被全部降解。3株菌在7d内对500 g/L粘度为1 746 mPa·s(50℃)的稠油降粘率分别为49.1%、46.6%和49.0%,而复合菌对稠油的降粘效果高于单一菌株,其降粘率达到57.0%。     

两株稠油高效降解菌的筛选鉴定及其降解性能研究

从广州石化厂曝气池周围的油泥中筛选驯化出2株可以降解稠油的菌株GSO2和GSO7,经16S rDNA序列分析鉴定这两株菌均属于不动杆菌属(Acinetobacter sp.).通过摇瓶振荡实验,对GSO2和GSO7在以稠油为唯一碳源时的生长情况、降解率及环境条件对降解率的影响进行了研究.结果表明,菌株GSO2和GSO7...     

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。...     

含油污泥中石油降解菌的分离及其降解特性

从渤海油田含油污泥中分离出3株石油烃降解菌,通过16S rRNA基因序列鉴定RS1、RS2和RS3分别为棒状杆菌、短杆菌和假单胞菌。经单因素实验确定,3株细菌对石油的最适降解条件分别为37℃、盐度3%、pH 8;32℃、盐度1%、pH 8;42℃、盐度1%、pH 6。降解实验结果表明,3株细菌30 d内对含油污泥中总石油烃的降解率分别为39.69%、31.13%和53.29%,而混合菌的降解效果明显高于单一菌株,降解率为58.08%;不同菌株对原油中不同组分的降解能力不同,其中,RS1对饱和烃的降解率最高,达20.74%,RS3对芳香烃的降解率最高,达到8.08%;GC-MS分析表明,混合菌对nC12~n-C34等正构烷烃均有明显降解,且对萘、苊、屈和苯并[b]荧蒽等多环芳烃的降解能力较强。     

集约化养猪废水SBR中17β-雌二醇高效降解菌的分离鉴定及其降解特性

从集约化养猪废水生物处理SBR的活性污泥中分离到3株高效降解17β-雌二醇(E2)的菌株,分别命名为ha、chs和hc。研究表明,这3株菌以E2为惟一碳源,在4 d内对初始浓度为1 mg/L E2的降解率为70%～95%。25℃条件下菌ha、chs和hc的一级反应动力学常数分别为0.0086、0.072和0.013。在温度为37℃时,3株菌的降解效率最高,在高浓度的氨氮和碱性pH的条件下,这3株菌均存在降解作用。其中,pH 9.05时,一级动力学常数菌ha降至0.0066,菌chs升至0.076,菌hc降至0.012。同时,在添加C源后,对降解有促进作用,并且C/N比在15∶1时降解效果较好。3株菌的一级反应动力学常数分别升到0.027、0.73和0.021。经16S rRNA基因序列分析鉴定为枯草芽孢肝菌(Bacillus subtilis)。     

石油降解菌群的筛选、构建及其降解特性研究

为了构建高效石油降解混合菌群,从潜江某油田采集8个石油污染土样(分别记为S1~S8)和2个石油污染水样(分别记为W3、W4),以石油为唯一碳源进行富集驯化培养;采用外观评分、石油降解率、石油3组分降解率、饱和烃中正构烷烃色谱分析等方法筛选石油降解优势菌群,构建石油降解混合菌群;采用正交试验研究混合菌群最佳降解条件。结果表明,富集的10个石油降解菌群中S3、S4、S5、S6、S8为优势菌群,培养30d后的石油降解率分别为21.67%、22.34%、27.23%、20.46%、19.99%;菌群W3、W4对石油乳化效果较好;混合菌群M3(S3+S4+S5+S8+W3+W4)为石油降解优势混合菌群,其最佳降解条件为35℃、pH7.60、含油率1.70%,在最佳条件下培养30d后,混合菌群M3对石油降解率达30.71%,比最优菌群S5的石油降解率提高了12.78%。     

高效氯氰菊酯降解菌群的结构分析及其降解特性研究

以连作10年以上的棉田土壤为材料,以高效氯氰菊酯为唯一碳源,驯化获得能稳定传代并持续降解高效氯氰菊酯的LZ1菌群,对菌群中可培养的细菌进行分离鉴定,最后对其降解高效氯氰菊酯的特性进行分析。结果表明,LZ1菌群中可分离、纯化优势菌株12株,经16SrRNA序列分析,其中10株与铜绿假单胞菌(Pseudomonas aeruginosa)相似性达99%,1株与无色杆菌(Achromobacter mucicolens)相似性达99%。高效氯氰菊酯最佳反应条件为高效氯氰菊酯初始质量浓度250mg/L、温度27℃、pH7.0、装样量200mL。在最佳反应条件下培养的LZ1菌群24h时对高效氯氰菊酯的降解率可达68.81%,132h时的降解率可达92.39%,且LZ1菌群对高效氯氰菊酯的4种异构体没有明显的降解特异性。     

一株微囊藻毒素降解菌的分离与鉴定

以水华蓝藻细胞中提取的微囊藻毒素为筛选物质,从太湖水华腐烂蓝藻中富集筛选出1株微囊藻毒素降解菌。该菌株革兰氏染色呈阴性,细胞细长杆状,菌落黄色,圆形,不透明,接触酶、氧化酶实验均呈阳性。16S rRNA基因序列的长度为1 416 bp(GenBank登录号为FJ976656)。系统发育树显示,该菌株与微嗜酸寡养单胞菌(Stenotrophomonas acidam-iniphila)的亲缘关系最近。通过菌株形态特征、生理生化特征和16S rRNA基因序列分析,将此菌株鉴定为微嗜酸寡养单胞菌,不同于已报道的微囊藻毒素降解菌属种。微囊藻毒素降解实验表明,该菌株5 d内将15.4 mg/L的微囊藻毒素完全降解,降解能力高于假单胞菌。     

一株DBP高效降解菌的分离、鉴定与降解性能

从镇江某垃圾站污染土壤中分离出1株能够以邻苯二甲酸二丁酯为唯一碳源和能源生长的细菌高效降解菌TM。经形态观察、生化鉴定、16S rRNA序列及系统发育分析,鉴定该菌株为变形假单胞菌(Pseudomonas plecoglossicida)。采用正交实验和单因素对照实验对这株菌株的降解条件进行优化,确定其最适生长条件为:温度30℃,p H=7.0。在最适降解条件下,其在72 h内对400 mg/L DBP降解率达到88.56%,为邻苯二甲酸二丁酯的高效降解菌。底物广谱性实验表明,该菌株邻苯二甲酸二辛脂(DOP)、邻苯二甲酸(2-乙基已基)酯(DEHP)都具有良好的降解能力,表明其具备良好的底物广谱性,说明该菌株在处理邻苯二甲酸酯类化合物的污染治理中有独特的应用潜力。     

Biodegradation of s-triazine herbicide atrazine by Enterobacter cloacae and Burkholderia cepacia sp. from long-term treated sugarcane-cultivated soils in Kenya

In this study soils from sugarcane-cultivated fields were screened for bacterial species capable of atrazine (6-chloro-N2-ethyl-N?-isopropyl-1,3,5-triazine-2,4-diamine) degradation due to long exposure of the soils to this herbicide. To enrich for atrazine degraders, Minimal Salt Medium containing atrazine as the sole N source and glucose as the C source was inoculated with soils impacted with this herbicide and incubated. Bacterial growth was monitored by measuring optical density. The degradation of atrazine was followed by measuring residual atrazine in liquid cultures over a given time period by high performance liquid chromatography. Bacterial strains isolated from the enrichment cultures were characterized by biochemical tests and identified by 16S rRNA gene sequencing. Two bacterial strains coded ISL 8 and ISL 15 isolated from two different fields were shown to have 94 and 96% 16S rRNA gene sequence similarity to Burkholderia cepacia respectively. Another bacterial sp., ISL 14 was closely related to Enterobacter cloacae with a 96% 16S rRNA gene sequence similarity. There was not much difference between the extents of atrazine degradation by the enrichment cultures with communities (79-82% applied amount) from which pure strains were isolated and the pure strains themselves in liquid cultures that showed a degradation of 53-83% of applied amount. The study showed existence of bacterial strains in different sugarcane-cultivated fields which can use atrazine as a nitrogen source. The bacterial strains isolated can be used to enhance the degradation of atrazine in contaminated soils where atrazine is still considered to be recalcitrant.     

Biodegradation of s-triazine herbicide atrazine by Enterobacter cloacae and Burkholderia cepacia sp. from long-term treated sugarcane-cultivated soils in Kenya

In this study soils from sugarcane-cultivated fields were screened for bacterial species capable of atrazine (6-chloro-N²-ethyl-N⁴-isopropyl-1,3,5-triazine-2,4-diamine) degradation due to long exposure of the soils to this herbicide. To enrich for atrazine degraders, Minimal Salt Medium containing atrazine as the sole N source and glucose as the C source was inoculated with soils impacted with this herbicide and incubated. Bacterial growth was monitored by measuring optical density. The degradation of atrazine was followed by measuring residual atrazine in liquid cultures over a given time period by high performance liquid chromatography. Bacterial strains isolated from the enrichment cultures were characterized by biochemical tests and identified by 16S rRNA gene sequencing. Two bacterial strains coded ISL 8 and ISL 15 isolated from two different fields were shown to have 94 and 96% 16S rRNA gene sequence similarity to Burkholderia cepacia respectively. Another bacterial sp., ISL 14 was closely related to Enterobacter cloacae with a 96% 16S rRNA gene sequence similarity. There was not much difference between the extents of atrazine degradation by the enrichment cultures with communities (79–82% applied amount) from which pure strains were isolated and the pure strains themselves in liquid cultures that showed a degradation of 53–83% of applied amount. The study showed existence of bacterial strains in different sugarcane-cultivated fields which can use atrazine as a nitrogen source. The bacterial strains isolated can be used to enhance the degradation of atrazine in contaminated soils where atrazine is still considered to be recalcitrant.     

菌源对多环芳烃降解菌的筛选及降解性能的影响

高效降解菌的筛选对利用生物修复技术有效去除环境中的多环芳烃具有重要意义。分别以石油污染土壤和焦化废水活性污泥为菌源,分离出芘降解菌和混合PAHs(菲、荧蒽和芘)降解菌共14株并对其降解性能进行对比研究。结果表明,筛选得到的菌株分别属于9个菌属,其中2种菌源共有的菌属为Mycobacterium sp.、Ralstonia sp.和Shinella sp.。芘和PAHs的高效降解菌(CP16和CM32)均属于分支杆菌属(Mycobacterium),来源于焦化废水活性污泥;菌株CP16对芘(50mg/L)的7 d降解率为74.99%,CM32对PAHs(菲50 mg/L、荧蒽和芘各10 mg/L)的7 d降解率为100%。因此,以焦化废水活性污泥为菌源更有利于获得高效的多环芳烃降解菌。     

Complete degradation of butyl benzyl phthalate by a defined bacterial consortium: role of individual isolates in the assimilation pathway

Two bacterial strains, in consortium, were isolated by enrichment techniques from municipal waste-contaminated soil, which utilized butyl benzyl phthalate (BBP) as the sole carbon source. One of the isolates was identified as Arthrobacter sp. strain WY and the other one as Acinetobacter sp. strain FW based on the morphological, nutritional and biochemical characteristics and 16S rRNA sequence analysis. Various metabolites of BBP engendered by Arthrobacter sp. strain WY were isolated and identified by a combination of chromatographic and spectrophotometric analyses, which revealed a pathway involving monobutylphthalate (MBuP), monobenzyl phthalate (MBzP), phthalic acid and protocatechuic acid. The protocatechuic acid in turn was processed by ortho-cleavage dioxygenase to form beta-carboxy-cis,cis-muconate, ultimately leading to the TCA cycle. The Arthrobacter sp. strain WY could not utilize the hydrolyzed alcohols of BBP. On the other hand, the Acinetobacter sp. strain FW, which by itself could not utilize BBP as the sole carbon source, is capable of utilizing the hydrolyzed alcohols of BBP. Benzyl alcohol was found to be metabolized by the Acinetobacter sp. strain FW via benzaldehyde, benzoic acid and catechol. Catechol was further degraded by ortho-cleavage dioxygenase to cis,cis-muconic acid and subsequently to muconolactone leading to beta-ketoadipate pathway. Moreover, the Acinetobacter sp. strain FW metabolized 1-butanol through butyraldehyde and butyric acid leading to the tricarboxylic acid cycle via beta-oxidation pathway. This is the first report on the complete degradation of BBP by a defined consortium describing the role of its individual constituents in the BBP assimilation pathway.     

油污土中降解柴油细菌的分离鉴定及降解能力研究

从所采集柴油污染土壤样品中富集、分离得到柴油降解优势菌株,命名为B-3和B-4.根据其生理生化性质及16S rDNA序列比对分析,确定2株菌分别属于Tetrathiobacter kashmirensis、假单胞菌属(Pseudomonas sp.).由于实验中,B-3的生长曲线较特殊,故以B-3和典型石油烃降解菌假单...     

一株碱性脱除硫酸盐细菌的筛选及其生长特性研究

生化铁碱溶液催化法气体脱硫方法（简称DDS法）具有良好脱硫效果，但是DDS溶液在脱硫后会导致脱硫能力降低，为了达到使DDS脱硫残液得到再生的目的，从自然环境中筛选能够使DDS脱硫残液得到再生的微生物并对其进行了研究。通过富集培养及纯化，从黑龙江省五大连池火山口附近土样中筛选出一株碱性条件下脱除硫酸盐的菌株WT-1。对该菌株的生长曲线进行了测定，培养4～6 h菌株进入对数期，20 h左右到达稳定期。并研究了温度、pH值和摇床转速对其生长特性和活性的影响，结果表明，该菌株的最适生长条件为：温度35～45℃，pH值8，摇床转速120 r/min。同时，脱硫试验表明WT-1确实具有脱除硫酸盐的能力。     

The rhizosphere and PAH amendment mediate impacts on functional and structural bacterial diversity in sandy peat soil

To reveal the degradation capacity of bacteria in PAH polluted soil and rhizosphere we combined bacterial extradiol ring-cleavage dioxygenase and 16S rRNA analysis in Betula pubescens rhizoremediation. Characterisation of the functional bacterial community by RFLP revealed novel environmental dioxygenases, and their putative hosts were studied by 16S rRNA amplification. Plant rhizosphere and PAH amendment effects were detected by the RFLP/T-RFLP analysis. Functional species richness increased in the birch rhizosphere and PAH amendment impacted the compositional diversity of the dioxygenases and the structural 16S rRNA community. A shift from an Acidobacteria and Verrucomicrobia dominated to an Alpha- and Betaproteobacteria dominated community structure was detected in polluted soil. Clone sequence analysis indicated catabolic significance of Burkholderia in PAH polluted soil. These results advance our understanding of rhizoremediation and unveil the extent of uncharacterized functional bacteria to benefit bioremediation by facilitating the development of the molecular tool box to monitor bacterial populations in biodegradation.     

Isolation and characterization of 3-nitrophenol-degrading bacteria associated with rhizosphere of Spirodela polyrrhiza

Introduction

The accelerated biodegradation of 3-nitrophenol (3-NP) in the rhizosphere of giant duckweed (Spirodela polyrrhiza) was investigated.

Materials and methods

Biodegradation of 3-nitrophenol in the rhizosphere of a floating aquatic plant, S. polyrrhiza, was investigated by using three river water samples supplemented with 10?mg?l^?1 of 3-NP. Isolation and enrichment culture of 3-NP-degrading bacteria were performed in basal salts medium containing 3-NP (50?mg?l^?1). The isolated strains were physiologically and phylogenetically characterized by using an API20NE kit and 16S rRNA gene sequencing.

Results and discussion

Accelerated removal of 3-NP (100%) was observed in river water samples with S. polyrrhiza compared with their removal in plant-free river water. Also, 3-NP persisted in an autoclaved solution with aseptic plants, suggesting that the accelerated 3-NP removal resulted largely from degradation by bacteria inhabiting the plant rather than from adsorption and uptake by the plant. We successfully isolated six and four strains of 3-NP-degrading bacteria from the roots of S. polyrrhiza and plant-free river water, respectively. Phylogenetic analysis based on 16S rRNA gene divided the 3-NP-degrading bacteria into two taxonomic groups: the genera Pseudomonas and Cupriavidus. The strains belonging to the genus Cupriavidus were only isolated from the roots of duckweed. All strains isolated from the roots utilized 3-NP (0.5?mM) as a sole carbon and energy source, indicating that they could have contributed to the accelerated degradation of 3-NP in the rhizosphere of S. polyrrhiza.

Conclusions

The rhizoremediation using S. polyrrhiza and its rhizosphere bacteria can be an effective strategy for cleaning up the 3-NP-contaminated surface waters.     

Contributions of fermentative acidogenic bacteria and sulfate-reducing bacteria to lactate degradation and sulfate reduction

The roles of fermentative acidogenic bacteria and sulfate-reducing bacteria (SRB) in lactate degradation and sulfate reduction in a sulfidogenic bioreactor were investigated by traditional chemical monitoring and culture-independent methods. A continuously stirred tank reactor fed with synthetic wastewater containing lactate and SO(2-)(4) at 35 degrees C, 10h of hydraulic retention time was used. The results showed that sulfate removal efficiency reached 99%, and sulfide and acetate were the main end products after 20 d of operation. 16S rRNA gene based clone libraries and single-strand conformation polymorphism profiles demonstrated that the proportion of SRB increased from 16% to 95%, and that Desulfobulbus spp., Desulfovibrio spp., Pseudomonas spp. and Clostridium spp. formed a stable, dominant community structure. The decreasing COD/SO(2-)(4) ratio had little effect on the community pattern except that Pseudomonas spp. and Desulfobulbus spp. increased slightly. The addition of molybdate to the influent significantly changed the microbial community, sulfate removal efficiency and the pattern of end products. Clostridium spp., Bacteroides spp. and Ruminococcus spp. became the dominant community members. The main end products switched from acetate to ethanol and then to propionate with the oxidation-reduction potentials increasing from -420 to -290 mV. A lactate degradation pathway was deduced: lactate served as the electronic donor for Desulfovibrio spp., or was fermented by Clostridium spp. and Bacteroides spp. to produce propionate or ethanol, which were subsequently utilized by Desulfobulbus spp. and Desulfovibrio spp. The acidotrophic SRB oxidized part of the acetate finally.