Steppe T.F., Pinckney J.L., Dyble J., Paerl H.W.
Institute of Marine Sciences, University of North Carolina-Chapel Hill, 3431 Arendell Street, Morehead City, NC 28557, USA.
Microb Ecol. 2001 Jan;41(1):36-44. doi: 10.1007/s002480000066.
N2 fixation (nitrogenase activity), primary production, and diazotrophic community composition of stromatolite mats from Highborne Cay, Exuma, Bahamas, were examined over a 2-year period (1997-1998). The purpose of the study was to characterize the ecophysiology of N2 fixation in modern marine stromatolites. Microbial mats are an integral surface component of these stromatolites and are hypothesized to have a major role in stromatolite formation and growth. The stromatolite mats contained active photosynthetic and diazotrophic assemblages that exhibited temporal separation of nitrogenase activity (NA) and photosynthesis. Maximal NA was detected at night. Seasonal differences in NA and net O2 production were observed. Photosynthetic activity and the availability of reduced organic carbon appear to be the key determinants of NA. Additions of the de novo protein synthesis inhibitor chloramphenicol did not inhibit NA in March 1998, but greatly inhibited NA in August 1998. Partial sequence analysis of the nifH gene indicates that a broad diversity of diazotrophs may be responsible for NA in the stromatolites.
在1997 - 1998年的两年时间里，对来自巴哈马群岛埃克苏马的海伯恩礁的叠层石席的固氮作用（固氮酶活性）、初级生产力和固氮微生物群落组成进行了研究。该研究的目的是描述现代海洋叠层石中固氮作用的生态生理学特征。微生物席是这些叠层石不可或缺的表面组成部分，据推测在叠层石的形成和生长中起主要作用。叠层石席含有活跃的光合和固氮组合，其固氮酶活性（NA）和光合作用表现出时间上的分离。最大的NA在夜间检测到。观察到NA和净氧气产生的季节性差异。光合活性和还原有机碳的可用性似乎是NA的关键决定因素。添加从头蛋白质合成抑制剂氯霉素在1998年3月没有抑制NA，但在1998年8月极大地抑制了NA。对nifH基因的部分序列分析表明，多种固氮微生物可能是叠层石中NA的原因。
