Streptomyces tirandamycinicus sp. nov., a Novel Marine Sponge-Derived Actinobacterium With Antibacterial Potential Against Streptococcus agalactiae

Abstract

A novel actinobacterium, strain HNM0039T, was isolated from a marine sponge sample collected at the coast of Wenchang, Hainan, China and its polyphasic taxonomy was studied. The isolate had morphological and chemical characteristics consistent with the genus Streptomyces. Based on the 16S rRNA gene sequence analysis, strain HNM0039T was closely related to Streptomyces wuyuanensis CGMCC 4.7042T (99.38%) and Streptomyces spongiicola HNM0071T (99.05%). The organism formed a well-delineated subclade with S. wuyuanensis CGMCC 4.7042T and S. spongiicola HNM0071T in the Streptomyces 16S rRNA gene tree. Multi-locus sequence analysis (MLSA) based on five house-keeping gene alleles (atpD, gyrB, rpoB, recA, trpB) further confirmed their relationship. DNA–DNA relatedness between strain HNM0039T and its closest type strains, namely S. wuyuanensis CGMCC 4.7042T and S. spongiicola HNM0071T, were 46.5 and 45.1%, respectively. The average nucleotide identity (ANI) between strain HNM0039T and its two neighbor strains were 89.65 and 91.44%, respectively. The complete genome size of strain HNM0039T was 7.2 Mbp, comprising 6226 predicted genes with DNA G+C content of 72.46 mol%. Thirty-one putative secondary metabolite biosynthetic gene clusters were also predicted in the genome of strain HNM0039T. Among them, the tirandamycin biosynthetic gene cluster has been characterized completely. The crude extract of strain HNM0039T exhibited potent antibacterial activity against Streptococcus agalactiae in Nile tilapia. And tirandamycins A and B were further identified as the active components with MIC values of 2.52 and 2.55 μg/ml, respectively. Based on genotypic and phenotypic characteristics, it is concluded that strain HNM0039T represents a novel species of the genus Streptomyces whose name was proposed as Streptomyces tirandamycinicus sp. nov. The type strain is HNM0039T (= CCTCC AA 2018045T = KCTC 49236T).

Genome Mining of the Genus Streptacidiphilus for Biosynthetic and Biodegradation Potential

“…Table 1 provides the summary of genomic features of all 11 Streptacidiphilus strains along with selected Streptomyces and Kitasatospora genomes. It can be noted that the number of pseudogenes is higher in both Kitasatospora and Streptacidiphilus than the Streptomyces genomes, although a higher number of pseudogenes has also been reported from Streptomyces as well [ 46 ]. Nevertheless, the function of these bacterial pseudogenes is debatable, and they are known to have short retention times as they undergo the process of degradation and removal by the accumulation of mutations [ 47 ].…”

Streptomyces from traditional medicine: sources of new innovations in antibiotic discovery

“…Chinese researchers recently reported the isolation of Streptomyces tirandamycinicus sp. nov., from a marine sponge with antibacterial potential against Streptococcus agalactiae [45]. Other researchers have isolated new compounds from Streptomyces associated with marine sponges in the Vietnam Sea, some of which are completely novel compounds active against both Gram-positive and Gram-negative bacteria and Mycobacterium tuberculosis [46].…”

The Biological and Chemical Diversity of Tetramic Acid Compounds from Marine-Derived Microorganisms

“…Compounds 30 and 31 are considered as the main antibacterial constituents of marine Streptomyces sp. [38,39]. Moreover, tirandamycin B (31) was reported to be a new lead scaffold for anti-filarial activity, as it can selectively inhibit Brugia malayi AsnRS (BmAsnRS) (IC 50 = 30 µM) and efficiently kill adult B. malayi parasite (IC 50 = 1 µM) in vitro without general cytotoxicity to human hepatic cells [40,41].…”

“…Chemical structures of 3-oligoenoyltetramic acids(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39).…”