Whole-Genome Analysis of <i>Novacetimonas cocois</i> and the Effects of Carbon Sources on Synthesis of Bacterial Cellulose

Novacetimonas cocois WE7 (formally named Komagataeibacter cocois WE7) is a strain isolated from contaminated coconut milk, capable of producing bacterial cellulose (BC). We sequenced its genome to investigate why WE7 cannot synthesize BC from glucose efficiently. It contains about 3.5 Mb and six plasmid DNAs. N. cocois WE7 contains two bcs operons (bacterial cellulose operon, bcs I and bcs II); the absence of bcs III operons may lead to reduced BC production. From genome predictions, glucose, sucrose, fructose, maltose, and glycerol can be utilized to generate BC, with WE7 unable to metabolize carbohydrate carbon sources through the Embden–Meyerhof–Parnas (EMP) pathway, but rather through the Hexose Monophosphate Pathway (HMP) and tricarboxylic acid (TCA) pathways. It has a complete gluconic acid production pathway, suggesting that BC yield might be very low when glucose, maltose, and trehalose are used as carbon sources. This study represents the first genome analysis of N. cocois. This information is crucial for understanding BC production and regulation mechanisms in N. cocois and lays a foundation for constructing engineered strains tailored for diverse BC application purposes

Insights into Proteomics Reveal Mechanisms of Ethanol-Enhanced Bacterial Cellulose Biosynthesis by <i>Komagataeibacter nataicola</i>

Nata de coco, known as bacterial cellulose (BC), has been given much attention in the food industry and biomaterial areas due to its specific properties such as low calorie content, high content of fiber, high purity and high biocompatibility. Komagataeibacter spp. are indispensable microorganisms for BC production due to their highly efficient production. Here, proteomics was applied to investigate the metabolism regulation mechanisms of BC yield improvements in K. nataicola Y19 by 48 ± 3% after ethanol supplementation. The results evidenced that differentially expressed proteins involved in the BC biosynthesis system, glycolytic pathway, TCA cycle and oxidative phosphorylation process were up-regulated. The proteins accelerated the BC biosynthesis by providing more energy and via intermediate metabolites. Furthermore, the elongation factor Tu, chaperone DnaK and translocase subunit SecB may be involved in the BC synthesis procedure by regulating electron transfer, hydrolysis of ATP and protein transformation. Moreover, the ethanol-enhanced BC biosynthesis may be associated with the decreased expression of endoglucanase. This research elucidates the proteomics mechanism of higher BC production based on ethanol addition, providing references for nata de coco production efficiency and the synthetic regulation of bacterial cellulose in the future