Zehr J P, Ohki K, Fujita Y
Marine Sciences Research Center, State University of New York, Stony Brook 11794.
J Bacteriol. 1991 Nov;173(21):7055-8. doi: 10.1128/jb.173.21.7055-7058.1991.
Members of the marine filamentous, nonheterocystous cyanobacterial genus Trichodesmium not only are capable of fixing nitrogen aerobically in the light but when grown under a light-dark cycle will fix nitrogen only during the light phase. In this study, we constructed a restriction map of the structural nitrogen fixation genes (nifHDK) in Trichodesmium sp. strain NIBB 1067. We found that the organization of the nif genes in Trichodesmium sp. strain NIBB 1067 is contiguous, as found in other nonheterocystous cyanobacteria and in heterocysts. Furthermore, the nif gene arrangement was identical when the cultures were grown with combined nitrogen or under nitrogen-fixing conditions. Therefore, no gene rearrangements occur, such as those that occur during the development of heterocysts in heterocystous species.
海洋丝状、无异形胞的蓝藻颤藻属成员不仅能够在光照下进行需氧固氮，而且在明暗循环条件下生长时，仅在光照阶段固氮。在本研究中，我们构建了颤藻属菌株 NIBB 1067 中结构性固氮基因（nifHDK）的限制酶切图谱。我们发现，颤藻属菌株 NIBB 1067 中的 nif 基因组织是连续的，这与其他无异形胞蓝藻和异形胞中的情况相同。此外，当培养物在结合态氮存在下生长或在固氮条件下生长时，nif 基因排列是相同的。因此，不会发生基因重排，比如在异形胞蓝藻物种异形胞发育过程中发生的那些重排。
