Abstract:
Gilliamella is a genus of bacteria commonly found as symbionts of corbiculate bees. Research into energy metabolism by this genus has predominantly been done through in vivo and in vitro experiments focused on the type species Gilliamella apicola. This study examined 95 publicly available genomes representing at least 18 Gilliamella species isolated predominantly from the hindgut of corbiculate bees. Energy metabolism pathways were found to be highly conserved across not only the Gilliamella but also other members of the family Orbaceae. Evidence suggests Gilliamella are capable of fermentation of both fumarate and pyruvate. Fermentation of the former produces succinate. Fermentation of the latter can produce acetate, ethanol, formate, and both isoforms of lactate for all Gilliamella and acetoin for some G. apicola strains. According to genomic evidence examined, all Gilliamella are only capable of respiration under microoxic conditions, while higher oxygen conditions likely inhibits respiration. Evidence suggests that the glycolysis and pentose phosphate pathways are essential mechanisms for the metabolism of energy sources, with the TCA cycle playing little to no role in energy metabolism for all Gilliamella species. Uptake of energy sources, i.e. sugars and derivatives, likely relies predominantly on the phosphoenol-pyruvate-dependent phosphotransferase system. Differences in the utilized energy sources may confer fitness advantages associated with specific host species.
摘要:
Gilliamella是细菌的一个属,通常被发现为针状蜜蜂的共生体。该属的能量代谢研究主要是通过体内和体外实验进行的,该实验的重点是Gilliamellaapicola型。这项研究检查了95个公开可用的基因组,这些基因组代表了至少18种主要从针状蜜蜂后肠分离的Gilliamella物种。发现能量代谢途径不仅在Gilliamella而且在Orbaceae家族的其他成员中都高度保守。有证据表明Gilliamella能够发酵富马酸盐和丙酮酸盐。前者的发酵产生琥珀酸。后者的发酵可以产生乙酸,乙醇,甲酸盐,以及所有Gilliamella的乳酸同种型和某些G.apicola菌株的丙酮蛋白。根据检查的基因组证据,所有Gilliamella都只能在微氧条件下呼吸,而较高的氧气条件可能会抑制呼吸。有证据表明,糖酵解和磷酸戊糖途径是能量代谢的重要机制,TCA循环在所有Gilliamella物种的能量代谢中几乎没有作用。吸收能源,即糖和衍生物,可能主要依赖于磷酸烯醇-丙酮酸依赖性磷酸转移酶系统。所利用的能量源的差异可以赋予与特定宿主物种相关的健身优势。