Comparative Genomics of High-Yielding Komagataeibacter diospyri Mutants Induced by Ultraviolet Light

Bacterial cellulose (BC) is one of the biodegradable materials that is produced by BC-producing bacteria and is widely used in various industries. In previous studies, we isolated high-yield BC-producing Komagataeibacter diospyri MI 2 and analyzed its genomes. In this study, we aimed to improve the BC production ability of K. diospyri MI 2 by UV light and to investigate BC-regulating genes by comparative genomics. Of the 17 surviving colonies after UV irradiation, most produced significantly more BC higher than the wild type, while K. diospyri mutants B, G, and O had the highest BC yield. The properties of BC were analyzed by SEM and X-ray diffraction. The results showed that the BC produced by the K. diospyri mutants was denser than that of the wild type but did not significantly change crystallinity. The whole-genome sequencing and comparative genomics were performed to explore the genes involved in the improvement of BC in the K. diospyri mutants. The result showed that the descriptive statistics of the assembled genomes of the K. diospyri mutants were similar to that of the wild type. When comparing their genomes, we found that genes, including galE, aes, and bfr, which were likely involved in BC biosynthesis, disappeared in the K. diospyri mutants. In addition, variant analysis was performed, and SNPs and InDels located on the CDS of genes, including the response regulator, efflux transporter outer membrane subunit, chloride channel protein, and ribonuclease E, could be potential biomarkers for higher BC production. Our study provided the K. diospyri mutants by UV mutagenesis and explored the set of genes possibly involved in BC production.