糖丝菌属放线菌研究进展

Recent advance on the genus Saccharothrix

摘要:

1984年美国著名放线菌分类学家Labeda建立的糖丝菌属(Saccharothrix)，是典型的丝状稀有放线菌重要类群之一。糖丝菌的气生菌丝在孢子形成过程中通常呈现锯齿状形态，细胞壁含meso-二氨基庚二酸，磷酸类脂主要包括磷脂酰乙醇胺，优势甲基萘醌是MK-9(H₄)和MK-10(H₄)，基因组中16S rRNA基因的特异性诊断核苷酸序列为CAC (607–609)和GTG (617–619)。近年来基因组学研究证实，糖丝菌基因组中存在丰富的聚酮合成酶、非核糖体多肽合成酶等基因簇，具有生物合成化学结构新颖、生物活性多样的次生代谢物与酶产物的潜能，且研究证实糖丝菌能够代谢产生已知抗生素的衍生物或新骨架结构的抗生素，如二硫吡咯酮类、内酰胺类、蒽环类和氯霉素等新抗生素，在抗病毒、抑菌和抗肿瘤等方面具有巨大的医药价值。同时，糖丝菌也是工业酶制剂生产菌种资源的新成员，在酶制剂应用方面具有较强的开发潜力，其代谢产生的几丁质酶、纤维素酶等新型活性酶在现代农业以及轻工业等领域有着广泛应用。另外，糖丝菌凭借自身独特的遗传代谢多样性在土壤有机污染物降解和重金属污染修复中扮演着重要角色。结合近期本实验室发表的一株糖丝菌新种，查阅相关文献资料，本文从糖丝菌属的分类学典型特征、基因组学、次级代谢产物生物合成以及产酶应用开发进行了综述，以期为进一步挖掘糖丝菌的应用潜力提供理论基础。

Abstract:

The genus Saccharothrix was established in 1984 by Labeda, a famous American taxonomist of actinobacteria. This genus is an important group of rare actinomycetes with filamentous hyphae, and most species have zigzag aerial hyphae during sporulation. They contained meso-diaminopimelic acid in cell wall, abundant phosphatidylethanolamine in phospholipids, MK-9(H₄) and MK-10(H₄) as the principal menaquinones, and the genus-specific motifs CAC (607–609) and GTG (617–619) in the 16S rRNA gene. Recent studies of genome mining have confirmed the existence of non-ribosomal peptide synthetase genes with high frequency in the genomes of Saccharothrix spp., which have the potential to produce structurally-novel secondary metabolites and enzyme products with diverse activities. Further, Saccharothrix can produce derivatives of known antibiotics or antibiotics with new structures, such as dithiopyrrolones, lactams, anthracyclines, and chloramphenicol, which have a great value in antiviral, antibacterial and antitumor treatment. Moreover, Saccharothrix serves as a new microbial resource for the production of industrial enzyme preparations, which has strong development potential in the application of enzyme preparations. New active enzymes such as chitinase and cellulase generated by the metabolism of Saccharothrix are widely used in modern agriculture, light industry and other fields. Owing to the unique genetic and metabolic diversity, Saccharothrix plays a key role in the degradation of organic pollutants and remediation of heavy metal pollution in soil. On the basis a novel species of Saccharothrix discovered by our laboratory and relevant literature, we reviewed the typical taxonomic characteristics, genomics, secondary metabolites, and enzyme development of Saccharothrix, aiming to provide a scientific basis for further mining the Saccharothrix strains with application potential.