Search Results (2)

Lichens have developed numerous adaptations to optimize their survival in various environmental conditions, largely by producing secondary compounds by the fungal partner. They often have antibiotic properties and are involved in protection against intensive UV radiation, pathogens, and herbivores. To contribute to the knowledge of the arsenal of secondary compounds in a crustose lichen species, we sequenced and assembled the genome of Toniniopsis dissimilis, an indicator of old-growth forests, using Oxford Nanopore Technologies (ONT, Oxford, UK) long reads. Our analyses focused on biosynthetic gene clusters (BGCs) and specifically on Type I Polyketide (T1PKS) genes involved in the biosynthesis of polyketides. We used the comparative genomic approach to compare the genome of T. dissimilis with six other members of the family Ramalinaceae and twenty additional lichen genomes from the database. With only six T1PKS genes, a comparatively low number of biosynthetic genes are present in the T. dissimilis genome; from those, two-thirds are putatively involved in melanin biosynthesis. The comparative analyses showed at least three potential pathways of melanin biosynthesis in T. dissimilis, namely via the formation of 1,3,6,8-tetrahydroxynaphthalene, naphthopyrone, or YWA1 putative precursors, which highlights its importance in T. dissimilis. In addition, we report the occurrence of genes encoding ribosomally synthesized and posttranslationally modified peptides (RiPPs) in lichens, with their highest number in T. dissimilis compared to other Ramalinaceae genomes. So far, no function has been assigned to RiPP-like proteins in lichens, which leaves potential for future research on this topic. Full article

Natural products produced by microorganisms are considered an important resource of bioactive secondary metabolites, such as anticancer, antifungal, antibiotic, and immunosuppressive molecules. Streptomyces are the richest source of bioactive natural products via possessing a wide number of secondary metabolite biosynthetic gene clusters (SM-BGCs). Based on rapid development in sequencing technologies with advances in genome mining, exploring the newly isolated Streptomyces species for possible new secondary metabolites is mandatory to find novel natural products. The isolated Streptomyces thinghirensis strain HM3 from arid and sandy texture soil in Qassim, SA, exerted inhibition activity against tested animal pathogenic Gram-positive bacteria and pathogenic fungal species. In this study, we report the draft genome of S. thinghirensis strain HM3, which consists of 7,139,324 base pairs (bp), with an average G+C content of 71.49%, predicting 7949 open reading frames, 12 rRNA operons (5S, 16S, 23S) and 60 tRNAs. An in silico analysis of strain HM3 genome by the antiSMASH and PRISM 4 online software for SM-BGCs predicted 16 clusters, including four terpene, one lantipeptide, one siderophore, two polyketide synthase (PKS), two non-ribosomal peptide synthetase (NRPS) cluster)/NRPS-like fragment, two RiPP/RiPP-like (ribosomally synthesised and post-translationally modified peptide product), two butyrolactone, one CDPS (tRNA-dependent cyclodipeptide synthases), and one other (cluster containing a secondary metabolite-related protein that does not fit into any other category) BGC. The presented BGCs inside the genome, along with antibacterial and antifungal activity, indicate that HM3 may represent an invaluable source for new secondary metabolites. Full article