产有机酸采油菌的筛选及产酸情况的分析

目的:从大庆油田原油样品中筛选出2株产有机酸量较高的菌株,并对其产物进行分析.方法:根据形态特征、生理生化性质和16S rDNA序列分析对菌株进行鉴定,并运用GC/MS法对发酵液进行分析.结果:经鉴定这两株为枯草芽孢杆菌,菌株T10 -3的发酵液中含有乙酸11.407％,异丁酸9.375％,丁二醇79.217％;菌株DH -2 -l发酵液的中含有异丁酸41.56％,丁二醇46.619％,异戊酸4.138％,异庚酸10.680％.结论:这两株细菌在微生物采油方面均有良好的应用前景.     

沙棘种子内生细菌对几种植物种子萌发的影响

目的:为探究沙棘种子内生细菌对兰州北山几种植物种子萌发的影响,促进其种子繁殖.方法:通过Salkowski比色法,从17株沙棘种子内生细菌中筛选出1株产吲哚乙酸(IAA)能力最强的菌株H2B03,采用其上清液和发酵液两种处理对北山植物种子进行萌发试验.结果:菌株H2B03产IAA的量为22.15μg·mL-1;在菌株H...     

泽普油田石油降解功能菌株的分离与鉴定

目的:在研究泽普油田产区菌株多态性的基础上,对石油降解功能菌株进行探讨。方法:通过稀释平板涂布法分离微生物;采用TLC和HPLC方法对分离菌株进行多糖成分鉴定,并进行16S rRNA和18S rRNA序列分析;采用溶血圈实验、排油圈法、石油黏度测定等方法,测定石油降解菌株降解能力。结果:分离菌株中有5株细菌和4株真菌,且菌株多糖的TLC分析结果与形态学鉴定结果基本相同;5株分离细菌中,2株细菌隶属于Bacillus属,3株细菌隶属于Enterobacter。另外4株真菌被鉴定为隶属于Penicillium属;分离菌株B2能降解石油。结论:泽普油田石油产区微生物的群落中存在一定丰度的细菌和真菌,含有B2的原油发酵液黏度为0.67±0.20 mPa.s.和原油在0.05水平上有显著性差异。推断B2对石油具有一定的降解能力。     

铜绿丽金龟蛴螬肠道产消化酶细菌的分离与鉴定

目的分离不同生态环境中铜绿丽金龟蛴螬肠道中产消化酶细菌,明确生态环境和食物对其肠道共生细菌产酶活性的影响。方法 2016年7月,自野外林间废弃的菜园和花生田分别采集蛴螬,鉴定出铜绿丽金龟蛴螬后,采用传统分离培养法对其肠道中的共生细菌进行分离鉴定,利用平板透明圈法分别进行淀粉酶、蛋白酶、脂肪酶和纤维素酶等的分泌能力测定。结果自铜绿丽金龟蛴螬肠道中共分离出细菌24株,其中在野生铜绿丽金龟蛴螬体内分离出9株,花生田铜绿丽金龟蛴螬体内分离出15株。野生蛴螬体内分离的细菌中,产淀粉酶菌株1株,产蛋白酶菌株4株,产纤维素酶菌株1株,产脂肪酶菌株1株;花生田蛴螬体内分离的细菌中,产淀粉酶菌株1株,产蛋白酶菌株3株,产纤维素酶菌株9株,未分离到产脂肪酶的菌株。结论野生铜绿丽金龟蛴螬肠道细菌中产蛋白酶种类较多,占44.4%;花生田铜绿丽金龟蛴螬肠道细菌中产纤维素酶菌株最多,所占比例可达60.0%,反映出生境和食性与昆虫肠道共生细菌产消化酶活性的相适应性。     

天山冻土产低温脂肪酶菌株的筛选及其多样性分析

【目的】通过天山冻土细菌的分离和产低温脂肪酶菌株的筛选,了解天山冻土微生物的物种多样性和产脂肪酶菌株的系统发育多样性,为高效低温脂肪酶生物技术奠定基础。【方法】采用稀浓度的R2A、TSB平板涂布分离天山冻土中可培养细菌,通过选择性培养基筛选产低温脂肪酶的菌株。采用细菌常规生理生化实验、最适生长温度、耐盐性、产酶性能对分离菌株的生理学进行研究,通过16S rRNA基因序列分析确定产脂肪酶菌种的系统进化地位,通过BOX-PCR指纹技术对16S rRNA基因高度同源性的菌株进一步区分。【结果】分离筛选到78株可培养低温菌,选择培养基显示有17株可产低温脂肪酶,其中8株在两种选择培养基中均可产脂肪酶和酯酶。17株产酶菌分别隶属于5个系统发育类群、6个属,其中假单胞菌属(Pseudomonas)占大多数(58.9%)。【结论】天山冻土中产低温脂肪酶的细菌具有较丰富的系统发育多样性,依据生长温度,均属于耐冷菌。     

产碱性蛋白酶细菌Bs08菌株的分离及其产酶特性的研究

在产蛋白酶细菌生态分布及产酶条件研究的基础上,对产碱性蛋白酶细菌进行了分离和筛选。从780株细菌中获得一株产酶活性较高的菌株。研究了该菌株的产酶特性,以及影响其产酶量的主要因素。     

产氢紫色非硫光合细菌的分离与筛选

从不同来源的样品中分离到5株紫色非硫光合细菌,从中筛选出2株产氢量较高的菌株——菌株D和菌株H。对其产氢动力学研究表明,在含有20mmol/L谷氨酸钠和50mmol/L D,L-苹果酸培养基中,两株菌可连续稳定产氢5—8d,其产氢速率分别为10.18和20.61μ/h·mg细胞干重。     

陕北地区提高石油采收率菌株筛选及其降解性能评价

筛选出可提高石油采收率的降解菌株。采用富集培养和稀释平板法,从陕北某采油厂附近长期受原油污染的水域和油污泥中筛选获得以原油为唯一碳源的降油菌株,并对其生长条件、排油圈能力、代谢产物表面活性物质、表面张力与乳化性及原油降解实验进行一系列的研究。含油废水和油污泥中筛选出10株细菌,从中选择了6株优势菌作为供试菌株进行后续研究,6株供试菌株均可使原油的理化性质发生变化。菌株B与原油作用后,使原油黏度降低了49.02%,菌株A-08、菌株5-13、菌株1-2及菌株A和菌株A-08复合菌群可使原油乳化为细小的圆型颗粒,与原油作用后,降解率达到43.25%-60.00%。     

天山一号冰川底部沉积层产蛋白酶耐低温菌株的筛选及其系统发育

[目的]通过对天山一号冰川底部沉积层耐低温菌的分离和其中产蛋白酶菌株的筛选,了解冰川微生物生理多样性和系统发育多样性,为高效低温蛋白酶生物技术的研发奠定基础.[方法]采用稀浓度的R2A、TSB平板涂布分离可培养细菌,通过脱脂乳选择性培养基筛选产蛋白酶的耐低温菌株.对分离菌株表型特征、生理生化特性、最适生长温度、耐盐性、产酶性能进行了比较,结合16S rRNA基因序列同源性分析确定产蛋白酶菌株的多样性和系统进化地位,通过BOX-PCR指纹技术分析16S rRNA基因序列高相似度的近缘菌株的遗传差异.[结果]从125株分离物中筛选到27株产蛋白酶的耐低温菌株,其中21株为适冷菌,仅6株菌为专性嗜冷菌,革兰氏阴性菌居多,假单胞菌属(Pseudomonas)菌株占40.7％.产酶菌株隶属于5个系统发育类群、9个属,其中γ-Proteobacteria、Actinobacteria、CFB(Cytophaga-Flexibacter-Bacteroides)为优势类群.[结论]天山1号冰川底部沉积层冻土中产蛋白酶的耐低温细菌多样性较丰富,本研究筛选得到的同属近缘种群较多,其产酶性状存在差异,适合开展微生物种群的生物地理学研究.     

水稻种子内生细菌多样性及其分泌植物生长素能力的测定

[目的]探讨水稻种子内生细菌的多样性并测定其分泌IAA能力.[方法]采用传统的可培养方法分离水稻种子内生细菌,并通过16S Rrna基因序列分析初步确定分离菌株的系统发育地位,利用比色法进一步对不同种类菌株产植物生长素(IAA)能力进行定性、定量检测.[结果]共分离纯化获得66株内生细菌菌株,分属于5个类群的15个属26个种.以26株细菌为代表对其进行分泌生长素(IAA)能力的定性及定量测定,共发现19株细菌可分泌生长素或其类似物,其中Z10、Z17、Z14和Z20 4株内生细菌具较强的分泌植物生长素能力.[讨论]分离得到的内生细菌表现了水稻种子内生细菌的多样性,其中某些细菌对植物有一定的促生功能.     

高效石油降解菌群的构建及对芳香烃化合物萘的协同降解性能

【背景】石油作为一类混杂有机化合物,一旦产生污染就会对人类和环境造成严重的危害。【目的】从新疆石油污染土壤中分离筛选石油降解菌,为石油污染土壤的生物修复提供数据支持及技术参考。【方法】以石油为唯一碳源,通过富集培养、筛选分离得到123株单菌,根据菌落形态挑选出30个不同形态菌株,通过16S rRNA基因序列确定其种属,构建系统发育树;通过原油降解实验筛选出高效石油降解菌,以芳香烃的标志化合物萘为唯一碳源筛选出高效降解菌株,并分别筛选可降解水杨酸、邻苯二酚的菌株。【结果】分离筛选出5株高效石油降解菌,降解率高于85%;萘、水杨酸和邻苯二酚降解菌株各获得一株,将3种菌株按照1:1:1的接种比例对萘进行降解,萘的降解率从单菌60.74%提升到89.40%,菌株间的分工协作可以提高有机物的降解效率。【结论】筛选得到的菌株丰富了石油降解微生物菌种库,不同微生物菌株之间的分工协作为石油污染物的降解提供了新思路,为进一步研究石油污染治理提供参考。     

海绵中石油降解微生物的分离筛选及降解特性研究

从大连湾原油污染海域生长的海绵中分离筛选到一株原油降解菌OA58,根据其生长形态、培养特征、16S rRNA序列相似性比对分析和生化指标检测,初步鉴定为脱叶链霉菌（Streptomyces exfoliatus）。同时,考察了该链霉菌对原油的降解效果,OA58能以原油为唯一碳源生长,在人工海水培养基中,14 d内对原油（初始浓度为1 g/L）的平均降解率为83%,是一株具有开发潜力的原油降解放线菌。     

胜利油田滩涂区石油降解菌的筛选、鉴定及其多样性分析

基于传统的实验方法,对胜利油田滩涂区土壤中石油降解菌进行了筛选和鉴定,并利用PCR-DGGE (变性梯度凝胶电泳)技术分析了胜利油田滩涂区的菌群多样性.结果表明：由研究区土壤中筛选出13株石油降解菌,其中,6株石油降解菌的石油降解率>90%,能降解大部分C₁₂～C₂₆的石油烷烃,系统发育学鉴定为Alcanivorax、Halomonas和Marinobacter,均属于γ-proteobacteria分支;胜利油田滩涂区未培养优势菌有Sulfurovum、Gillisia和Arcobacter;该区优势菌群中γ-proteobacteria所占比重较大,其次为α-proteobactiria、ε-proteobactiria、Actinobacteria 和Flavobacteria.     

高效降解石油细菌的分离鉴定及降解能力的研究

目的:为获得高效降解原油的菌株,从石油污染严重的土壤中采样,富集分离得到原油降解菌,并初步考察它们降解原油的能力。方法:通过富集培养、多次筛选分离得到三株优势菌,编号为SWH-1、SWH-2和SWH-3。通过16S rDNA序列分析和NCBI数据库的Blast比对分析,对其鉴定到种。通过差量法测定它们在室内摇瓶中对原油的降解率。结果:经鉴定,这三株菌分别为枯草芽孢杆菌(Bacillus subtillus)、多食鞘氨醇杆菌(Sphingobacterium multivorum)和嗜温鞘氨醇杆菌(Sphingobacterium thalpophi-lum)。在0.5g/L的原油培养基内培养1w,SWH-1和SWH-2的降解率较高,分别为33.89%和46.31%。将这两株菌进行混合培养降解原油,降解率高达51.73%。结论:所筛选到的枯草芽孢杆菌和多食鞘氨醇杆菌在生物修复方面具有很好的应用潜力,而且多食鞘氨醇杆菌在石油降解方面的报道尚属首次。     

青海油田微生物采油技术研究

从青海油田地层水中分离培养出4株微生物菌种,对其进行了耐温性、耐盐性等进行了探讨,分析了微生物处理前后原油组份及物性变化情况,并采用岩芯流动试验探讨了微生物的驱油效果。结果表明,这几种微生物菌种均能适应青海油田温度及高矿化度地层环境,作用于原油后对原油中的长链饱和烃类物质有较好的降解作用,能使其分子链变短,并产生有机酸或石油羧酸盐类表面活性剂等低分子物质,使原油的粘度、凝点及蜡含量均出现明显的下降,改善原油的流动性能。提高石油采收率。2口井的现场试验证明,微生物采油具有良好的提高石油采收率的效果和清蜡减阻效果。     

实时荧光PCR在治理石油污染中的应用

石油污染已成为全球最严重的环境问题之一,运用生物学方法治理石油污染逐渐成为研究热点。从大港油田原油样品中筛选到12株能降解原油的菌株,分别对其降解特性进行了研究。其中,被命名为BS的菌株对原油的降解效果最好,降解率高达89.1%,经16S rDNA序列比对,与Bacillus subtilis BSn5的相似性达100%。通过生物信息学的方法,分析菌株B.subtilis BSn5的代谢途径,该菌株中有11个基因参与石油烃类化合物的降解过程。最后利用实时荧光PCR技术,测定在石油降解过程中起重要作用的烷基羟化酶基因(alkB)在菌株BS与标准菌株B.subtilis BSn5中的表达量,结果显示,该基因在菌株BS中的表达量较标准菌株B.subtilis BSn5高约2倍,这可能与菌株BS的生存环境有关。为检测和分析石油污染,筛选含有降解石油功能基因的微生物及构建工程菌株提供了新的手段。     

Simultaneous hydrocarbon biodegradation and biosurfactant production by oilfield-selected bacteria

Aims: To study the bacterial diversity associated with hydrocarbon biodegradation potentiality and biosurfactant production of Tunisian oilfields bacteria. Methods and Results: Eight Tunisian hydrocarbonoclastic oilfields bacteria have been isolated and selected for further characterization studies. Phylogenetic analysis revealed that three thermophilic strains belonged to the genera Geobacillus, Bacillus and Brevibacillus, and that five mesophilic strains belonged to the genera Pseudomonas, Lysinibacillus, Achromobacter and Halomonas. The bacterial strains were cultivated on crude oil as sole carbon and energy sources, in the presence of different NaCl concentrations (1, 5 and 10%, w/v), and at 37 or 55°C. The hydrocarbon biodegradation potential of each strain was quantified by GC–MS. Strain C450R, phylogenetically related to the species Pseudomonas aeruginosa, showed the maximum crude oil degradation potentiality. During the growth of strain C450R on crude oil (2%, v/v), the emulsifying activity (E24) and glycoside content increased and reached values of 77 and 1·33 g l^?1, respectively. In addition, the surface tension (ST) decreased from 68 to 35·1 mN m^?1, suggesting the production of a rhamnolipid biosurfactant. Crude biosurfactant had been partially purified and characterized. It showed interest stability against temperature and salinity increasing and important emulsifying activity against oils and hydrocarbons. Conclusions: The results of this study showed the presence of diverse aerobic bacteria in Tunisian oilfields including mesophilic, thermophilic and halotolerant strains with interesting aliphatic hydrocarbon degradation potentiality, mainly for the most biosurfactant produced strains. Significance and Impact of the Study: It may be suggested that the bacterial isolates are suitable candidates for practical field application for effective in situ bioremediation of hydrocarbon‐contaminated sites.     

Bioremediation potential of hydrocarbon degrading bacteria: isolation,characterization, and assessment

Oil contamination is a worldwide concern now. However, oil contaminated environment is enriched with microorganisms that can utilize petroleum oil and use hydrocarbon for their growth, nutrition and metabolic activities. In the present study, bacteria present in the oil contaminated soil were isolated by enrichment culture technique using Minimal Salt (MS) media supplemented with diesel oil and burned engine oil as a sole carbon source. The isolated bacteria were characterized by morphological and biochemical tests and identified by molecular tool through cycle sequencing method. Three isolates were morphologically characterized as gram-negative, cocci shaped and 16S rRNA sequence analysis revealed that the isolates are closely related to Pseudomonas sp., Acinetobacter sp., and Enterobacter sp. respectively. Growth condition was optimized at pH 7.0 and temperature 37 °C. All the isolates were susceptible to several antibiotics and they have no antagonistic effect with soil beneficial bacteria. Three isolates were grown in two different concentrations of diesel oil and burned engine oil (4% v/v and 8%, v/v) respectively. Study revealed that with increasing the concentration of diesel oil in the media the growth rate of all the isolates were decreased. In contrast, the growth rates of all the three isolates were increased, with increasing concentration of burned engine oil. In our study, all the isolates showed their degradation efficacy in 4% v/v diesel oil and in 8% v/v burned engine oil. So, our research clearly shows that the isolates could be potentially used for bioremediation purposes for cleaning up petroleum polluted area.     

一株来自大西洋表层海水的烷烃降解菌Gordonia sp. S14-10的分离鉴定及其降解相关特性的分析

摘要：【目的】本研究的目的是从大西洋表层海水分离筛选新的烷烃降解菌,了解其降解基因及降解特性,为海洋石油污染的生物治理提供材料。【方法】以柴油与原油作为混合碳源从大西洋表层海水样品中富集、并分离筛选出降解能力较强的烷烃降解菌。根据16S rRNA基因和其看家基因secA1序列确定其系统进化地位。分析了烷烃降解范围、表面活性剂产生能力及其他生理生化特性;利用已报道的兼并引物进行了烷烃羟化酶基因的PCR扩增及系统进化分析。【结果】分离筛选得到1株能够降解C10?C36直链烷烃的菌株S14-10。经16S rR     

Phylogenetic diversity of bacterial communities associated with bioremediation of crude oil in microcosms

Bioremediation, mainly by indigenous bacteria, has been regarded as an effective way to clean up oil pollution after an oil spill. In order to obtain a systematic understanding of the succession of bacterial communities associated with oil bioremediation, sediments collected from the Penglai 19-3 oil platform were co-incubated with crude oil. Oil biodegradation was assessed on the basis of changes in oil composition monitored by GC–MS. Changes in the bacterial community structure were detected by two 16S rRNA gene based culture-independent methods, denaturing gradient gel electrophoresis (DGGE) and clone library. The results suggested that crude oil was rapidly degraded during the 30-day bioremediation period. Bacteria affiliated with the genus Pseudomonas dominated all three clone libraries. But dramatic changes were also detected in the process of biodegradation of crude oil. The “professional hydrocarbonocastic bacteria” (e.g., Alcanivorax) became abundant in the two samples during the bioremediation period. Meanwhile, δ-proteobacteria was only detected in the two samples. Information on the bacterial community revealed in this study will be useful in developing strategies for bioremediation of crude oil dispersed in the marine ecosystem.