Supplementary tables for Honey Bee symbiont buffers larvae against nutritional stress and supplements lysine

Honey bees have suffered dramatic losses in recent years, largely due to multiple stressors underpinned by poor nutrition. Nutritional stress especially harms larvae, who mature into workers unable to meet the needs of their colony. In this study, we characterize the metabolic capabilities of a honey bee larvae-associated bacterium, Bombella apis (formerly Parasaccharibacter apium), and its effects on the nutritional resilience of larvae. We found that B. apis is the only bacterium associated with larvae that can withstand the antimicrobial larval diet. Further, we found that B. apis can synthesize all essential amino acids and significantly alters the amino acid content of synthetic larval diet, largely by supplying the essential amino acid lysine. Analyses of gene gain/loss across the phylogeny suggest that four amino acid transporters were gained in recent B. apis ancestors. In addition, the transporter LysE is conserved across all sequenced strains of B. apis. Finally, we tested the...近年来，蜜蜂种群遭遇了大幅衰减，该现象主要由多重胁迫因素引发，而营养匮乏正是这些胁迫的核心驱动因素。营养胁迫尤其会对幼虫造成损害，受影响的幼虫羽化为工蜂后，将无法满足蜂群的生存需求。本研究针对一种与蜜蜂幼虫共生的细菌——蜂房芽孢杆菌（Bombella apis，原名为Parasaccharibacter apium）的代谢功能及其对幼虫营养抗逆性的影响展开了表征分析。研究发现，蜂房芽孢杆菌是唯一一种能够耐受幼虫抗菌日粮的幼虫共生细菌。进一步研究表明，该菌可合成全部必需氨基酸，并可通过提供必需氨基酸赖氨酸（lysine）显著改变人工幼虫日粮的氨基酸组成。基于系统发育的基因得失分析显示，蜂房芽孢杆菌的近期祖先获得了四种氨基酸转运蛋白编码基因。此外，氨基酸转运蛋白LysE在所有已测序的蜂房芽孢杆菌菌株中均保持保守。最后，本研究对……进行了测试