Project description:Welan gum is mainly produced by Sphingomonas sp. ATCC 31555 and has broad applications in industry such as that in cement production. Both carbon and nitrogen sources are essential for welan production. However, how nitrogen sources affect the metabolism and gene transcription of welan remains elusive. Here, we used next-generation sequencing RNA-seq to analyze the transcriptome of Sphingomonas sp. ATCC 31555 in the presence of inorganic or organic nitrogen sources. Enriched gene expression and pathway analysis suggest that organic nitrogen sources significantly enhanced the expression of genes in central metabolic pathways of Sphingomonas sp. ATCC 31555 and those critical for welan synthesis compared to that observed using inorganic nitrogen sources. The present study improves our understanding of the molecular mechanism underlying the use of nitrogen in welan synthesis in Sphingomonas sp., as well as provides an important transcriptome resource for Sphingomonas sp. in relation to nitrogen sources.