PDF(Pubmed)
Abstract：
Deep-sea environments, as relatively unexplored extremes within the Earth\'s biosphere, exhibit notable distinctions from terrestrial habitats. To thrive in these extreme conditions, deep-sea actinomycetes have evolved unique biochemical metabolisms and physiological capabilities to ensure their survival in this niche. In this study, five actinomycetes strains were isolated and identified from the Mariana Trench via the culture-dependent method and 16S rRNA sequencing approach. The antimicrobial activity of Microbacterium sp. B1075 was found to be the most potent, and therefore, it was selected as the target strain. Molecular networking analysis via the Global Natural Products Social Molecular Networking (GNPS) platform identified 25 flavonoid compounds as flavonoid secondary metabolites. Among these, genistein was purified and identified as a bioactive compound with significant antibacterial activity. The complete synthesis pathway for genistein was proposed within strain B1075 based on whole-genome sequencing data, with the key gene being CHS (encoding chalcone synthase). The expression of the gene CHS was significantly regulated by high hydrostatic pressure, with a consequent impact on the production of flavonoid compounds in strain B1075, revealing the relationship between actinomycetes\' synthesis of flavonoid-like secondary metabolites and their adaptation to high-pressure environments at the molecular level. These results not only expand our understanding of deep-sea microorganisms but also hold promise for providing valuable insights into the development of novel pharmaceuticals in the field of biopharmaceuticals.
摘要：
深海环境，作为地球生物圈内相对未探索的极端，表现出与陆地栖息地的显著区别。为了在这些极端条件下茁壮成长，深海放线菌已经进化出独特的生化代谢和生理能力，以确保它们在这个生态位生存。在这项研究中,通过培养依赖性方法和16SrRNA测序方法，从马里亚纳海沟中分离并鉴定了5个放线菌菌株。微杆菌属的抗菌活性。B1075被发现是最有效的，因此,它被选为目标菌株。通过全球天然产品社会分子网络（GNPS）平台进行的分子网络分析确定了25种类黄酮化合物为类黄酮次生代谢产物。其中,金雀异黄素被纯化并鉴定为具有显著抗菌活性的生物活性化合物。基于全基因组测序数据，在菌株B1075中提出了金雀异黄素的完整合成途径，关键基因是CHS（编码查尔酮合成酶）。CHS基因的表达受到高静水压力的显著调控,从而影响菌株B1075中类黄酮化合物的产生，揭示了放线菌合成类黄酮次生代谢产物与其在分子水平上适应高压环境之间的关系。这些结果不仅扩大了我们对深海微生物的理解，而且有望为生物制药领域新型药物的开发提供有价值的见解。
