Cellulose is the most abundant and widely used biopolymer on earth and can be produced by both plants and micro-organisms. Among bacterial cellulose (BC)-producing bacteria, the strains in genus Komagataeibacter have attracted wide attention due to their particular ability in furthering BC production. Our previous study reported a new strain of genus Komagataeibacter from a vinegar factory. To evaluate its capacity for BC production from different carbon sources, the present study subjected the strain to media spiked with 2% acetate, ethanol, fructose, glucose, lactose, mannitol or sucrose. Then the BC productivity, BC characteristics and biochemical transformation pathways of various carbon sources were fully investigated. After 14 days of incubation, strain W1 produced 0.040–1.529 g L⁻¹ BC, the highest yield being observed in fructose. Unlike BC yields, the morphology and microfibrils of BCs from different carbon sources were similar, with an average diameter of 35–50 nm. X-ray diffraction analysis showed that all membranes produced from various carbon sources had 1–3 typical diffraction peaks, and the highest crystallinity (i.e., 90%) was found for BC produced from mannitol. Similarly, several typical spectra bands obtained by Fourier transform infrared spectroscopy were similar for the BCs produced from different carbon sources, as was the I_α fraction. The genome annotation and Kyoto Encyclopedia of Genes and Genomes analysis revealed that the biochemical transformation pathways associated with the utilization of and BC production from fructose, glucose, glycerol, and mannitol were found in strain W1, but this was not the case for other carbon sources. Our data provides suggestions for further investigations of strain W1 to produce BC by using low molecular weight sugars and gives clues to understand how this strain produces BC based on metabolic pathway analysis.

Rice (Oryza sativa L.) feeds ~3 billion people. Due to the wide occurrence of arsenic (As) pollution in paddy soils and its efficient plant uptake, As in rice grains presents health risks. Genetic manipulation may offer an effective approach to reduce As accumulation in rice grains. The genetics of As uptake and metabolism have been elucidated and target genes have been identified for genetic engineering to reduce As accumulation in grains. Key processes controlling As in grains include As uptake, arsenite (AsIII) efflux, arsenate (AsV) reduction and AsIII sequestration, and As methylation and volatilization. Recent advances, including characterization of AsV uptake transporter OsPT8, AsV reductase OsHAC1;1 and OsHAC1;2, rice glutaredoxins, and rice ABC transporter OsABCC1, make many possibilities to develop low-arsenic rice.

In the last few decades, bacteria capable of bacterial cellulose (BC) synthesis and the characterization of BC have been well-documented. In this study, a new BC-producing bacterial strain was isolated from fermented vinegar. The BC morphology, composition and diameter distribution, and the genes associated with BC production were analyzed. The results showed that one out of five isolates belonging to Komagataeibacter was a BC-producer, which mostly produced the typical cellulose I consisting of nanofibrils and had several functional groups similar to typing paper (i.e., plant cellulose). Several known genes such as glk, pgm and UPG2 in glucose metabolisms, bcsA, bcsB, bcsC and bcsD in BC synthesis and cmcax, ccpAx, bglxA and other genes in BC synthesis regulation or c-di-GMP metabolisms have also been found in the strain W1 based on genome sequencing and gene annotations. The functions of BcsX and BcxY might also be important for BC synthesis in Komagataeibacter sp. W1. Our study provided a new BC-producing bacterial strain that could be used to prepare high-quality BC and to study BC synthesis mechanisms.