Methylocella palustris gen. nov., sp nov., a new methane-oxidizing acidophilic bacterium from peat bags, representing a novel subtype of serine-pathway methanotrophs
Methylocella palustris gen. nov., sp nov., a new methane-oxidizing acidophilic bacterium from peat bags, representing a novel subtype of serine-pathway methanotrophs
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DOI：
10.1099/00207713-50-3-955
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发表时间：
2000-05-01
影响因子：
2.8
通讯作者：
Tiedje, JM
中科院分区：
文献类型：
--
作者：
Dedysh, SN;Liesack, W;Tiedje, JM
从酸性泥炭沼泽中分离出3株甲烷氧化细菌，提出了一个新属Methylocella和一个新种Methylocella palustris。这些细菌是需氧的、革兰氏阴性的、无色的、不运动的、笔直和弯曲的杆状体，它们利用丝氨酸途径进行碳同化，通过正常的细胞分裂繁殖，并含有细胞内的聚β -羟基丁酸颗粒（两极）。这些菌株以甲烷和甲烷作为碳和能量的唯一来源，是中等嗜酸生物，生长在ph 4.5 - 7.0之间，ph 5.0-5.5为最佳。生长温度范围为10 ~ 28℃，最适温度为15 ~ 20℃，胞质膜系统与ⅰ型和ⅱ型甲烷氧化菌不同。细胞具有广阔的质周空间和与细胞质膜相连的囊泡膜系统。菌株仅在低盐培养基（0.2 ~ 0.5 g l(-1)）上生长。这三种菌株都具有可溶性甲烷单加氧酶，并且能够通过对氧敏感的氮酶固定大气中的氮。以颗粒甲烷单加氧酶为目标引物的PCR未见产物；用pmoA探针杂交也呈阴性。主要的磷脂脂肪酸是18:1的酸。DNA的G+C含量为61.2 mol%。这三种菌株具有相同的16S rRNA基因序列，代表了变形菌纲cc亚类中甲烷氧化细菌的新谱系，与甲基化菌群的II型甲烷氧化菌仅中度相关。这3株菌株与嗜酸异养细菌Beijerinckia indica subsp关系最密切。16S rDNA序列相似度为96.5%。总的来说，这些菌株组成了一个新种和属，Methylocella palustris gen. nov., sp. nov.；应变K-T （= ATCC 700799(T)）为型应变。
A new genus, Methylocella, and a new species, Methylocella palustris, are proposed for three strains of methane-oxidizing bacteria isolated from acidic Sphagnum peat bogs. These bacteria are aerobic, Cram-negative, colourless, non-motile, straight and curved rods that utilize the serine pathway for carbon assimilation, multiply by normal cell division and contain intracellular poly-beta-hydroxybutyrate granules tone at each pole). These strains use methane and methanal as sole sources of carbon and energy and are moderately acidophilic organisms with growth between ph 4.5 and ph 7.0, the optimum being at ph 5.0-5.5. The temperature range for growth is 10-28 degrees C with the optimum at 15-20 degrees C. The intracytoplasmic membrane system is different from those of type I and II methanotrophs. Cells contain an extensive periplasmic space and a vesicular membrane system connected to the cytoplasmic membrane. The strains grew only on media with a low salt content (0.2-0.5 g l(-1)). All three strains were found to possess soluble methane monooxygenase and are able to fix atmospheric nitrogen via an oxygen-sensitive nitrogenase. No products were observed in a PCR with particulate methane monooxygenase-targeted primers; hybridization with a pmoA probe was also negative. The major phospholipid fatty acids are 18:1 acids. The G+C content of the DNA is 61.2 mol%. The three strains share identical 16S rRNA gene sequences and represent a novel lineage of methane-oxidizing bacteria within the cc-subclass of the class Proteobacteria and are only moderately related to type II methanotrophs of the Methylocystis-Methylosinus group. The three strains are most closely related to the acidophilic heterotrophic bacterium Beijerinckia indica subsp. indica (96.5% 16S rDNA sequence similarity). Collectively, these strains comprise a new species and genus Methylocella palustris gen. nov., sp. nov.; strain K-T (= ATCC 700799(T)) is the type strain.