Breznakia blatticola gen. nov. sp. nov. and Breznakia pachnodae sp. nov., two fermenting bacteria isolated from insect guts, and emended description of the family Erysipelotrichaceae

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• 作者：Dorothee Tegtmeier^a ; Cornelius Riese^a ; Oliver Geissinger^a ; Renate Radek^b ; Andreas Brune^a ; ^{brune@mpi-marburg.mpg.de" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Insect gut bacteria ; Erysipelotrichaceae ; Novel genus ; Obligately anaerobic ; Mixed-acid fermentation ; Emended family description
• 刊名：Systematic and Applied Microbiology
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：39
• 期：5
• 页码：319-329
• 全文大小：4034 K

文摘

Two novel, obligately anaerobic Firmicutes from the family Erysipelotrichaceae were isolated from the intestinal tracts of a cockroach (strain ErySL, Shelfordella lateralis) and a scarab beetle larva (strain Pei061, Pachnoda ephippiata). Phylogenetic analysis indicated that the strains belong to a monophyletic group of hitherto uncultured bacteria from insect guts that are only distantly related to any described species (<90% 16S rRNA gene sequence similarity). Ultrastructural analysis revealed a Gram-positive cell envelope and, in the case of strain ErySL, a wide electron-lucent space between the cytoplasmic membrane and cell wall. In older cultures, cells formed pleomorphic rods with a thicker peptidoglycan layer. Both strains were obligately anaerobic and fermented glucose to formate, ethanol, and acetate as major products, but strain Pei061 tolerated up to 1% oxygen in the headspace. The same type of metabolism was observed with Erysipelothrix inopinata, except that the latter grew, albeit poorly, even under air. However, previous claims of a microaerophilic or facultatively anaerobic metabolism in the genus Erysipelothrix could not be substantiated. Based on phenotypic and phylogenetic evidence, we propose to classify the isolates as members of a new genus, Breznakia blatticola gen. nov. sp. nov. and Breznakia pachnodae sp. nov., with strain ErySL^T (=DSM 28867^T = JCM 30190^T) and strain Pei061^T (=DSM 16784^T = JCM 30191^T) as type strains, and provide an emended description of the family Erysipelotrichaceae.