Insight into Saccharothrix espanaensis Grown in Different Media:Transcriptome and Natural Product Analysis

In this study, we show that cultivating of Saccharothrix espanaensis in the amino acid-rich SPY medium led to the detection of antibacterial and antifungal products. The cultivation in GYM-, HA- or NL111-medium did not lead to the production of these compounds. Four products were isolated from Saccharothrix espanaensis-SPY culture and determined as the known compounds anthranilic acid, indol-3-carboxylic acid, benzoic acid, and phenylacetic acid. In order to investigate the influence of SPY medium on gene transcription and to identify candidate genes involved in the biosynthesis of the purified compounds a comparative RNA sequencing analysis of Saccharothrix espanaensis cultivated in different media was performed. Total transcriptome analysis demonstrated that media composition has an influence on the expression of several genes. Among them are genes encoding enzymes belong to amino acid metabolism enzymes. Furthermore, based on the collected data genes involved in the biosynthesis of anthranilic acid, indol-3-carboxylic acid, benzoic acid, and phenylacetic acid could be predicted. Deletion of the genes BN6_01860 and BN6_67950 revealed their importance in the biosynthesis of indole-3-carboxylic acid and benzoic acid, respectively.