Abstract:
Microbial lipids, used as taxonomic markers and physiological indicators, have mainly been studied through cultivation. However, this approach is limited due to the scarcity of cultures of environmental microbes, thereby restricting insights into the diversity of lipids and their ecological roles. Addressing this limitation, here we apply metalipidomics combined with metagenomics in the Black Sea, classifying and tentatively identifying 1623 lipid-like species across 18 lipid classes. We discovered over 200 novel, abundant, and structurally diverse sphingolipids in euxinic waters, including unique 1-deoxysphingolipids with long-chain fatty acids and sulfur-containing groups. Sphingolipids were thought to be rare in bacteria and their molecular and ecological functions in bacterial membranes remain elusive. However, genomic analysis focused on sphingolipid biosynthesis genes revealed that members of 38 bacterial phyla in the Black Sea can synthesize sphingolipids, representing a 4-fold increase from previously known capabilities and accounting for up to 25% of the microbial community. These sphingolipids appear to be involved in oxidative stress response, cell wall remodeling, and are associated with the metabolism of nitrogen-containing molecules. Our findings underscore the effectiveness of multi-omics approaches in exploring microbial chemical ecology.
摘要:
微生物脂质,用作分类标记和生理指标,主要是通过种植研究。然而,由于环境微生物培养物的缺乏,这种方法是有限的,从而限制了对脂质多样性及其生态作用的认识。解决这一限制,在这里,我们将金属脂质组学与黑海的宏基因组学结合起来,在18个脂质类别中对1623个类脂物种进行分类和初步鉴定。我们发现了200多本小说,丰富,和结构上不同的鞘脂,包括具有长链脂肪酸和含硫基团的独特的1-脱氧鞘脂。鞘脂被认为在细菌中很少见,它们在细菌膜中的分子和生态功能仍然难以捉摸。然而,专注于鞘脂生物合成基因的基因组分析显示,黑海38个细菌门的成员可以合成鞘脂,代表比以前已知的能力增加了四倍,占微生物群落的25%。这些鞘脂似乎参与了氧化应激反应,细胞壁重塑,并与含氮分子的代谢有关。我们的发现强调了多组学方法在探索微生物化学生态学中的有效性。