Project description:Aquatic microbial communities contain a vast amount of genetic diversity and we have much to learn about how this manifests to functional diversity. Existing long-term time series data includes 16S tags, metagenomes, single amplified genomes (SAGs), and genomes from metagenomes (GFMs). Information about functional diversity and metabolic capabilities is often unavailable. The study sites include three lakes that are the subject of intense study through the North Temperate Lakes Long Term Ecological Research site: Sparkling Lake (oligotrophic), Lake Mendota (eutrophic), and Trout Bog Lake (dystrophic).
The work (proposal:https://doi.org/10.46936/10.25585/60000947) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
Project description:Activating the cryptic secondary metabolic gene clusters is a vital research field in Streptomyces. The marine Streptomyces sp. FJNU027 strain which could produce tirandamycins was cultured in the oligotrophic medium. Compared with normal medium, a differential product in oligotrophic culture was found by HPLC assay. After mass fermentation, 2 mg of the differential product was obtained from 30 L fermentation broth by solvent extraction, column chromatography over sephadex LH-20 and reverse phase C18, and other methods. It was identified as 4,4',5,5'-tetramethyl-[1,1'- diphenyl]-2,2'-diol by NMR and MS data. The production of this compound was enhanced with the increment of cultural time. Transcriptome sequencing analysis showed that the highest upregulated genes under oligotrophic condition were glycosidase, TraR/DksA C4-type zinc finger protein and ribonuclease encoding genes, while the expression of a MarR family transcriptional regulator was most significantly decreased under oligotrophic condition. The results indicate that oligotrophic culture is an effective method for altering the secondary metabolism of Streptomyces.
