Excavation of resources of Streptomyces species in frozen soils of the Qinghai-Tibet Plateau based on RpfA protein of Streptomyces coelicolor

This study is aimed at the actual demand for exploring new species resources of <i>Streptomyces</i>, and aims to solve the technical bottleneck of <i>Streptomyces</i> isolation and culture. A new method was established based on the resuscitation function of the RpfA protein from <i>Streptomyces coelicolor</i> CGMCC 4.1658^T to isolate unculturable or difficult-to-culture <i>Streptomyces</i> species, and it was applied to explore <i>Streptomyces</i> species resources in special habitats in the frozen soils of the Qinghai-Tibet Plateau. The RpfA protein of <i>S. coelicolor</i> was heterologously expressed and validated for its <i>in vitro</i> activity. The purified RpfA protein was then used to isolate <i>Streptomyces</i> from soil samples in the frozen soils of the Qinghai-Tibet Plateau, followed by an investigation into the impact of the RpfA protein on the cultivability of <i>Streptomyces</i> species. The results showed that the RpfA protein had a significant promoting effect on the germination of spores of both <i>S. coelicolor</i> itself and other species of the <i>Streptomyces</i> genus, and when a suitable concentration of RpfA protein was added to the culture medium, it could significantly improve the culturability of members of phylum <i>Actinomycetota</i>, especially <i>Streptomyces</i> species. In addition, many new species of the genus <i>Streptomyces</i> and other genera of phylum <i>Actinomycetota</i> were discovered. This study provides a new approach for further exploring <i>Streptomyces</i> species resources in special environments such as the Qinghai-Tibet Plateau and developing new biologically active substances produced by <i>Streptomyces</i>.