Rhodobium pfennigii sp nov., a phototrophic our le non-sulfur bacterium with unusual bacteriochlorophyll a antennae, isolated from a brackish microbial mat on Rangiroa atoll, French Polynesia
Rhodobium pfennigii sp nov., a phototrophic our le non-sulfur bacterium with unusual bacteriochlorophyll a antennae, isolated from a brackish microbial mat on Rangiroa atoll, French Polynesia
复制标题
DOI：
10.1099/ijs.0.64775-0
复制
发表时间：
2007-06-01
影响因子：
2.8
通讯作者：
Matheron, Robert
中科院分区：
文献类型：
--
作者：
Caumette, Pierre;Guyoneaud, Remy;Matheron, Robert
一种新的出芽紫色非硫细菌（菌株AR 2102（T））分离纯培养的微生物垫，已开发的咸水池塘的珊瑚边缘的Rangiroa（土阿莫土群岛，法属波利尼西亚）。该菌株的单细胞呈杆状，靠极鞭毛运动，芽殖分裂。它们的胞内光合膜均为板层型。细菌叶绿素a和类胡萝卜素的正常类藻黄素系列，与藻黄素作为主要的类胡萝卜素，作为光合色素。细菌叶绿素a在光谱的红外部分中的吸收在909 nm处表现出不寻常的体内吸收峰。该菌株在光异养条件下生长最佳，但在微氧条件下可以在硫代硫酸盐或化学有机营养条件下生长。最佳生长发生在1- 2%NaCl的存在下。16 S rRNA基因的比较序列分析将菌株AR 2102（T）置于α变形菌纲中，与Rhodobium属物种聚簇。这群细菌的代表形成了一个密切相关的群体，由轻度到中度耐盐的嗜盐、杆状、紫色非硫细菌组成，它们通过出芽分裂。新的分离株表现出一些差异，在生理（不利用醇或碳水化合物）和遗传特性（低相关性的DNA-DNA杂交），以及在其与光（吸收波长的差异）从以前描述的Rhodobium物种。因此，我们建议菌株AR 2102（T）（=DSM 17143（T）=ATCC BAA-1145（T））应被认为是Rhodobium属中的一个新物种的模式菌株，Rhodobium pfennibiensis sp.
A novel budding purple non-sulfur bacterium (strain AR2102(T)) was isolated in pure culture from a microbial mat that had developed in brackish-water ponds on the coral rim of the atoll of Rangiroa (Tuamotu Islands, French Polynesia). Single cells of this strain were rod-shaped and motile by means of polar flagella and divided by budding. Their intracellular photosynthetic membranes were of the lamellar type. Bacteriochlorophyll a and carotenoids of the normal spirilloxanthin series, with spirilloxanthin as the main carotenoid, were present as photosynthetic pigments. Bacteriochlorophyll a absorption in the infrared portion of the light spectrum exhibited an unusual in vivo absorption peak at 909 nm. The strain grew optimally under photoheterotrophic conditions, but could grow photolithotrophically on thiosulfate or chemo-organotrophically under micro-oxic conditions. Optimal growth occurred in the presence of 1-2 % NaCl. Comparative sequence analysis of the 16S rRNA gene placed strain AR2102(T) within the class Alphaproteobacteria, in a cluster with Rhodobium species. Representatives of this cluster form a closely related group of slightly to moderately halotolerant to halophilic, rod-shaped, purple non-sulfur bacteria that divide by budding. The new isolate exhibited some differences in physiology (no utilization of alcohols or carbohydrates) and genetic characteristics (low relatedness in DNA-DNA hybridization) as well as in its relation to light (differences in absorption wavelengths) from previously described Rhodobium species. Consequently, we propose that strain AR2102(T) (=DSM 17143(T) =ATCC BAA-1145(T)) should be considered as the type strain of a novel species within the genus Rhodobium, Rhodobium pfennigii sp.