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161.
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), δ13CPOC, total hydrolysable amino acid enantiomers (l- and d- amino acids) concentration and composition. δ13CPOC 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
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以柴油为唯一碳源和能源,从南极海水海冰微生物资源库中筛选到一株石油烃低温降解菌希瓦氏菌NJ49,并对影响其生长和降解率的环境因素(pH、温度、盐度、营养盐和表面活性剂)进行了初步研究。结果表明:希瓦氏菌NJ49可作为低温海域石油烃污染生物修复的菌源,其生长和降解的最适条件为:初始pH7.5,温度15℃,盐度6%,摇瓶装量80ml,最佳氮源硝酸铵,最佳磷源为磷酸二氢钾和磷酸氢二钾的混合物,添加表面活性剂可促进希瓦氏菌NJ49的生长和生物降解率。 相似文献
167.
Most-probable-number (MPN) dilution series were used to enumerate and isolate bacteria from bulk water, suspended aggregates, the oxic layer, and the oxic–anoxic transition zone of the sediment of a tidal flat ecosystem in the southern North Sea. The heterotrophic aerobic bacteria were able to grow on agar-agar, alginate, cellulose, chitin, dried and ground Fucus vesiculosus, Marine Broth 2216, palmitate, and starch. MPN counts of bulk water and aggregate samples ranged between 0.18?×?101 and 1.1?×?106 cells per milliliter and those of the sediment surface and the transition zone between 0.8?×?101 and 5.1?×?107 cells per gram dry weight. Marine Broth and F. vesiculosus yielded the highest values of all substrates tested and corresponded to 2.3–32% of 4,6-diamidinophenyl indole cell counts. Strains of seven phylogenetic classes were obtained: Actinobacteria, Bacilli, α- and γ-Proteobacteria, Sphingobacteria, Flavobacteria, and Planctomycetacia. Only with agar-agar as substrate could organisms of all seven classes be isolated. 相似文献
168.
Chuan Zhao Thorsten Brinkhoff Malte Burchardt Meinhard Simon Gunther Wittstock 《Ocean Dynamics》2009,59(2):305-315
Adhesion of two marine bacteria Shewanella sp. strain T1 and Pseudoalteromonas sp. strain T8, on differently terminated alkanethiolate self-assembled monolayers on gold was investigated. The selected
model surfaces—terminated by CH3, OH, NH2, COOH, OH-terminated oligo(ethylene glycol), and methyl-terminated oligo(ethylene glycol)—are characterized by contact angle
measurement using water, methylene iodide, 1-bromonaphthalene, and formamide. Surface free energies were calculated. Cell
counting of the two bacterial strains on the model surfaces after different times revealed differences between the two strains
by at least one order of magnitude. For the different surfaces, the bacteria showed comparably small selectivity. Atomic force
microscopy images of adhered bacteria showed very different fingerprints on the different surfaces.
Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible to authorized users. 相似文献
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