Simmons S L, Sievert S M, Frankel R B, Bazylinski D A, Edwards K J
Geomirobiology Group, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA.
Appl Environ Microbiol. 2004 Oct;70(10):6230-9. doi: 10.1128/AEM.70.10.6230-6239.2004.
The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion that was present in relatively constant abundance over the course of the season. This rod is the first MB that appears to belong to the gamma-Proteobacteria, which may suggest an iron- rather than sulfur-based respiratory metabolism. Its distribution and phylogenetic identity suggest that an alternative model for the ecological and physiological role of magnetotaxis is needed for greigite-producing MB.
2002年整个夏季，在马萨诸塞州法尔茅斯的半咸水盐沼中，研究了趋磁细菌（MB）的发生和分布与物理和化学条件的关系。在化学分层中观察到三种主要的MB形态类型。小型微需氧产磁铁矿球菌出现在化学分层的顶部，而产硫复铁矿的成簇细菌出现在化学分层的底部。这些菌群的分布在水柱内小尺度范围内的丰度变化剧烈，且种群丰度存在强烈的季节性波动。我们在硫化物温跃层中鉴定出一种新型的产硫复铁矿杆菌，其在整个季节中丰度相对恒定。这种杆菌是第一种似乎属于γ-变形菌纲的MB，这可能表明其呼吸代谢基于铁而非硫。它的分布和系统发育特征表明，对于产硫复铁矿的MB，需要一种关于趋磁生态和生理作用的替代模型。
