Complete Genome Sequence of Komagataeibacter hansenii LMG 23726T.

This study reports the release of the complete nucleotide sequence of Komagataeibacter hansenii LMG 23726T This organism is a cellulose producer, and its genome may provide more information to aid in the understanding of the genes necessary for cellulose biosynthesis.

GENOME ANNOUNCEMENT

Komagataeibacter hansenii LMG 23726T, previously known as Gluconacetobacter hansenii, is a Gram-negative, nitrogen-fixing, cellulose-producing, rod-shaped cell that was isolated from Kombucha tea (1, 2). This strain is closely related to other Komagataeibacter strains that are particularly efficient producers of pure, highly crystalline cellulose known as bacterial cellulose (BC) (1 – 5). BC is synthesized through pores along the long axis of the cell which associate in a hierarchical cell-directed self-assembly process to form ribbons and ultimately a membrane located at the air–liquid interface (6 – 8). Because of its ultrafine reticulated structure, high crystallinity, great mechanical strength, high water-holding capacity, moldability during formation, and biocompatibility, BC is well suited for medical, industrial, and commercial applications (9 – 12). The purpose of this report is to contribute to the data available to provide further insight into the molecular mechanisms of bacterial cellulose biosynthesis and add to the study of Gluconacetobacter spp.

Here, we present the genome of Komagataeibacter hansenii strain LMG 23726T (BCCM). The DNA was extracted and subjected to sequencing using an Illumina HiSeq 2000 PE100 system (University of Texas at Austin, ICMB Core Facility). The reads were downloaded into Geneious version 8.1.2 and assembled into contigs using Velvet version 1/2/02 (13), where it was revealed that the genome is approximately 3.6 Mb in size with a G+C content of 59.3% (14). A total of 3,733 open reading frames were predicted using Glimmer (15). Annotation data on contigs containing cellulose synthase genes were determined.

Preliminary phylogenetic analysis using 16S rRNA genes determined that this new strain is closely related to K. hansenii ATCC 23769. A homology comparison to the acsABCD operon of K. hansenii ATCC 23769 (GenBank accession no. AB091060) was performed and resulted in a 99.8% identity to acsAB, 99.5% identity to acsC, and 100% identity to acsD. Further investigations into the genome indicated that K. hansenii LMG 23726T contains a total of three separate coding regions for cellulose biosynthesis: acsABCD, acsAII, and acsABC. These three operons are also found in K. hansenii ATCC 23769. A homology comparison of the shared cellulose-synthesizing regions revealed a sequence identity of 74.5% identity to acsAII and 99.6% identity to acsABC. The acsABCD operon is flanked by genes coding for proteins which have been determined to be essential for proper cellulose biosynthesis to occur: cmcAx, ccpAx, and bglAx (16 – 19). These genes shared, respectively, 99.7%, 98.6%, and 99.3% sequence identities to K. hansenii ATCC 23769.

Further investigations into the genome of K. hansenii LMG 23726T may provide more insight into the mechanisms necessary for cellulose biosynthesis.

Accession number(s).

This whole-genome shotgun project has been deposited in DDBJ/ENA/GenBank under the accession number MJMD00000000. The version described in this paper is the first version, MJMD01000000.