A study of crude oil‐degrading bacteria from mangrove forests in the Persian Gulf     

Iman Fakhrzadegan  Mehdi Hassanshahian  Majid Askari Hesni  Amir Saadatfar 《Marine Ecology》2019,40(2)

Mangroves are coastal ecosystems, found in tropical and subtropical regions around the world. They are found in the transitional zones between land, sea, and rivers. Petroleum hydrocarbons are the most common environmental pollutants, and oil spills pose a great hazard to mangroves forests. This research was focused on the isolation and characterization of crude oil‐degrading bacteria from mangrove ecosystems at the Persian Gulf. Sixty‐one crude oil‐degrading bacteria were isolated from mangrove samples (plant, sediment, and seawater) that enriched in ONR7a medium with crude oil as only carbon source. Some screening tests such as growth at high concentration of crude oil, bioemulsifier production, and surface hydrophobicity were done to select the most efficient strains for crude oil degradation. Molecular identification of strains was carried out by amplification of the 16S rRNA gene by PCR. The results of this study were indicated that the quantity of crude oil‐degrading bacteria was higher in the root of mangrove plants compare to other mangrove samples (sediment and seawater). Also, identification results confirmed that these isolated strains belong to Vibrio sp. strain NW4, Idiomarina sp. strain BW32, Kangiella sp. strain DP40, Marinobacter sp. strain DW44, Halomonas sp. strain BS53, and Vibrio sp. strain DS35. The application of bioremediation strategies with these bacteria can reduce crude oil pollution in this important marine environment.  相似文献   

南海沉积物细菌胞外蛋白酶在家族水平上的多样性   总被引：2，自引：0，他引：2  

杨金玉  冯阳阳  陈秀兰  解彬彬  张玉忠  石梅  张熙颖 《海洋学报(英文版)》2019,38(12):73-83

海洋产蛋白酶细菌及其分泌的胞外蛋白酶在降解有机氮以推动海洋氮循环进行方面发挥着重要作用，但目前对这二者多样性的认识非常有限。本研究自南海沉积物中筛选得到90株产蛋白酶细菌，并通过N-端氨基酸序列，分析了其胞外蛋白酶在家族水平上的多样性。16S rRNA基因序列分析的结果表明，筛选的产蛋白酶细菌均属于Gammaproteobacteria纲，且大多数属于Alteromonadales目和Vibrionales目的不同属。对其中14株菌株的14个胞外蛋白酶的N-端氨基酸序列分析表明，所有这些蛋白酶属于金属蛋白酶的M4家族或丝氨酸蛋白酶的S8家族。本研究提供了海洋沉积物产蛋白酶细菌在类群及其胞外蛋白酶在类型上的新细节，这将有助于全面了解微生物酶促降解海洋沉积物有机氮的过程和机理。  相似文献   

胶州湾沉积物中石油降解菌的降解能力及多样性研究     

高伟  高祥兴  米铁柱  韩彬  张毅然  李馨子  尹晓斐  孙承君  李倩  崔志松  栾晓  于志刚  郑立 《海洋学报(英文版)》2019,38(6):54-64

2013年青岛输油管道爆炸，大量石油污染了附近海岸。课题组采集了污染的沉积物样品，以原油为唯一碳源和能源，富集了四个石油降解菌群。生物多样性和群落分析表明，Luteibacter、Parvibaculum 和属于食烷菌科的一个属是降解菌群的主要优势菌，都属于变形菌门。从石油降解菌群中分离筛选，获得了9株具有不同16S rRNA基因序列的降解菌，分别属于8个属。重量法测定降解菌的石油降解率，其中5株的石油降解率大于30%。GC-MS分析结果表明，石油降解菌多倾向于降解烷烃，对多环芳烃的降解能力较差，其中5株细菌的烷烃降解率较大，仅1株菌D2对多环芳烃的降解率较大，其降解率在34.9%到77.5%。通过对高通量数据的分析，表明食烷菌属是菌群A和菌群E的主要降解菌群，其中筛选获得的菌株E4可能是菌群E的一株优势降解菌。本研究所筛选菌株证明了其石油降解潜力，为油污染海滩生物修复提供了菌株资源。  相似文献   

Uncertainty in modelling of faecal coliform overland transport associated with manure application in Maryland     

A. K. Guber  Y. A. Pachepsky  A. M. Yakirevich  D. R. Shelton  A. M. Sadeghi  D. C. Goodrich  C. L. Unkrich 《水文研究》2011,25(15):2393-2404

Concerns for microbial safety of surface water facilitate development of predictive models that estimate concentrations and total numbers of pathogen and indicator organisms leaving manure‐fertilized fields in overland flow during runoff events. Spatial variability of bacterial concentrations in applied manure introduces high uncertainty in the model predictions. The objective of this work was to evaluate the uncertainty in model predictions of the manure‐borne bacteria overland transport caused by limited information on the spatial distribution of bacteria in surface‐applied manure. Experiments were carried out at the ARS Beltsville experimental watershed site (OPE3) in Maryland. Dairy bovine manure was applied at a 59·3 t/ha rate on the 3·55 hectare experimental field. Faecal coliform (FC) concentrations in manure measured in 2004, 2005, 2007, and 2009 varied by 4 orders of magnitude each year. Both runoff volume and FC concentrations in runoff water were monitored using a runoff flume equipped with a refrigerated pump sampler. Two runoff events occurred before the manure was incorporated into the soil. A bacteria transport add‐on module simulator of transport with infiltration and runoff (STWIR) was linked with the event‐based kinematic runoff and erosion model (KINEROS2) to simulate convective‐dispersive overland transport, bacteria release from manure, reversible attachment–detachment to soil, and surface straining of infiltrating bacteria. The model was successfully calibrated with the field experiment data. Monte Carlo simulations were carried out to account for the spatial variation in FC in applied manure and uncertainty in the FC distribution in manure caused by the small number of samples. A tenfold and twofold variation in FC concentrations in the runoff were obtained within the 90% probability interval when initial FC spatial distributions in the manure were represented by 5 and 29 samples, respectively. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Bacteria‐sediment associations in an alpine,freshwater environment and their effects on particle size,density and settling velocity          下载免费PDF全文

David C. Barrett  Kyle R. Hodder 《地球表面变化过程与地形》2018,43(10):2232-2242

This study measures the presence of bacteria‐sediment associations (BSAs) in an alpine, glacier‐fed watershed in the Southern Coast Mountains of British Columbia, Canada. The impact of BSAs on the creation of flocculated particles and their settling velocity are quantified using a laser transmissometer. Results from the study indicate that BSAs are present in the watershed and vary over both space and time. The percentage of bacteria associated with sediment particles was found to range from < 1% to 40%. Major sources of planktonic bacteria such as agricultural land and wastewater treatment outflow co‐occur with large decreases in the BSA ratio. Laboratory analysis demonstrates that an increase in the concentration of bacteria was associated with a decrease in the volume concentration of small particles, and a decrease in both estimated density and measured settling velocity for particles in larger size classes; consistent with flocculated particles of increasing complexity arising from combinations of primary particles and/or BSAs. Paleoenvironmental reconstructions using laminated lake sediments in alpine, glacier‐fed systems benefit from a fuller understanding of the geomorphologic processes by which they formed. While bacteria are noted to enhance formation of flocculated particles in laboratory systems, their impact upon geomorphic processes in natural systems have yet to be fully explored. © 2018 The Authors. Earth Surface Processes and Landforms published by John Wiley & Sons Ltd.  相似文献   

基于硫酸盐还原菌作用的油菜秆固定床处理模拟含Cr（Ⅵ）废水     

刘畅  陈天虎  周跃飞  金杰 《矿物学报》2011,31(4):742-749

探讨了固定床除Cr工艺以油菜秆为微生物生长的缓释碳源,含SRB的混合微生物和油菜秆对Cr（Ⅵ）的还原和固定的共同作用。动态实验分2阶段开展：初始2周的驯化阶段和梯度增加Cr（Ⅵ）浓度的除Cr实验阶段。除Cr实验中,间歇对固定床出水pH、氧化还原电位、SO42-及硫化物浓度、DOC、Cr（Ⅵ）浓度进行测试,实验结束后对固定床中固体产物进行SEM、EDS和XPS等分析。结果表明,油菜秆固定床处理模拟含Cr（Ⅵ）废水效果明显。当进水Cr（Ⅵ）浓度ρ[Cr（Ⅵ）]〈19.52 mg/L时,出水Cr（Ⅵ）和Cr（Ⅲ）浓度均低于排放标准（0.05 mg/L）;Cr（Ⅵ）被还原为Cr（Ⅲ）,Cr（Ⅲ）以氢氧化物的形式沉淀附着于油菜秆和其它固体物质之上。分析认为,油菜秆在固定床处理模拟含Cr（Ⅵ）废水中所起的作用主要包括3方面（作为微生物生长的缓释碳源;吸附Cr（Ⅵ）,降低其对微生物的毒性;作为Cr（Ⅲ）矿化产物的沉淀附着界面）;Cr（Ⅵ）主要通过SRB的直接作用及H2S的作用被还原为Cr（Ⅲ）;以油菜秆为碳源的固定床处理Cr（Ⅵ）的浓度上限介于15.05～19.52mg/L之间。  相似文献   

Origin and biochemical cycling of particulate nitrogen in the Mandovi estuary   总被引：2，自引：0，他引：2  

Loreta Fernandes 《Estuarine, Coastal and Shelf Science》2011,94(3):291-298

Mandovi estuary is a tropical estuary strongly influenced by the southwest monsoon. In order to understand, sources and fate of particulate organic nitrogen, suspended particulate matter (SPM) collected from various locations, was analyzed for particulate organic carbon (POC) and particulate organic nitrogen (PON), δ¹³C_POC, total hydrolysable amino acid enantiomers (l- and d- amino acids) concentration and composition. δ¹³C_POC values were depleted (−32 to −25‰) during the monsoon and enriched (−29.6 to −21‰) in the pre-monsoon season implying that OM was derived from terrestrial and marine sources during the former and latter season, respectively. The biological indicators such as C/N ratio, d-amino acids, THAA yields and degradation indices (DI) indicate that the particulate organic matter (POM) was relatively more degraded during the monsoon season. Conversely, during the pre-monsoon, the biological indicators indicated the presence of relatively fresh and labile POM derived from autochthonous sources. Amino acids such as alanine, aspartic acid, leucine, serine, arginine, and threonine in monsoon and glutamic acid, glycine, valine, lysine, and isoleucine in pre-monsoon were relatively abundant. Presence of bacterial biomarker, d-amino acids in the SPM of the estuary during both the seasons signifies important contribution of bacteria to the estuarine detrital ON pool. Based on d-amino acid yields, bacterial OM accounted for 16-34% (23.0 ± 6.7%) of POC and 29-75% (47.9 ± 18.7%) of PON in monsoon, and 30-78% (50.0 ± 15%) of POC and 34-79% (51.2 ± 13.3%) of the PON in pre-monsoon in the estuary. Substantial contribution of bacterial-N to PON indicates nitrogen (N) enrichment on terrestrial POM during the monsoon season. Transport of terrestrial POM enriched with bacterial OM to the coastal waters is expected to influence coastal productivity and ecosystem functioning during the monsoon season.  相似文献   

海胆相关菌株抗菌活性筛选及其生物学特性     

黄苛  刘祝祥  陈奇辉  贺建武  粟银  张丽  陈义光 《海洋科学》2011,35(8):25-31

以8个菌株（3株革兰氏阳性菌、3株革兰氏阴性菌和2株真菌）作为指示菌,采用管碟法对分离自南海硇洲岛马粪海hP-（Hemicentrotuspulcherrimus）中的106株细菌（含放线菌）进行抗菌活性筛选,并对其中抗菌活性较强的菌株进行了基于16SrRNA基因序列的系统发育分析和生物学特性研究。结果显示．具有抗菌活...  相似文献   

2006年秋季长江口及邻近海域微微型浮游生物的分布特征及环境影响因素   总被引：3，自引：0，他引：3  

乐凤凤  刘诚刚  郝锵  史君贤  翟红昌 《海洋学研究》2011,(3):108-117

2006年10月在长江口及邻近海域采用流式细胞技术测定了微微型浮游生物:聚球藻Synechococcus、微微型光合真核生物(picoeukaryotes)和异养浮游细菌(heterotrophic bacteria)的丰度和碳生物量,研究了其生态分布特点,并分析了其与环境因子之间的关系.结果表明,聚球藻、微微型光合真...  相似文献   

两株河口湿地耐盐石油降解菌的生物学特性及降解能力研究     

张竹圆  白洁  周方  蔡忠亚  赵阳国  田伟君 《海洋湖沼通报》2011,(1):147-153

从辽河口湿地污染土壤样品中分离筛选出2株高效石油降解茵lhk-2和lhk-10,经鉴定lhk-2为巴氏萄萄球菌(Staphylococcus pasteuri),lhk-10为嗜麦芽寡养单胞菌(Stenotrophomonasmaltophili).两株菌的石油降解能力研究结果表明,培养8d后,加菌组的石油烃降解率均在...  相似文献