Insights into Bacterial Cellulose Biosynthesis from Different Carbon Sources and the Associated Biochemical Transformation Pathways in Komagataeibacter sp. W1

Abstract

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 Iα 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.

Set-Up of Bacterial Cellulose Production From the Genus Komagataeibacter and Its Use in a Gluten-Free Bakery Product as a Case Study

“…Nevertheless, the pH decrease resulting from its conversion into gluconic acid dampened the BC yield, so that the higher buffer effect of peptone compared to ammonium sulfate or urea was decisive for enhancing the polymer production. However, in a recent paper Wang et al (2018) summarized the results of many works on cellulose yield, concluding that the effect of the strain was the dominant one rather than the carbon source used. This conclusion has been corroborated by our findings where even isolates from sub-cultures of the same strain showed different productivity and behavior, though the structural characteristics of the cellulose synthesized were quite similar.…”

“…Molecular mechanisms underlying the expression of genes for cellulose synthesis in Komagataeibacter spp. strains have to be well elucidated yet, although certain studies have been focussed on them (Augimeri and Strap, 2015; Wang et al, 2018). In order to optimize a BC large-scale production Gullo et al (2019) recently proposed a strategy that integrate information deriving from technological and genomic data.…”

“…In 2010, Jagannath et al (2010) proposed the use of BC from the same bacterial species as a cryoprotective and carrier to support probiotic bacteria in starter cultures production and dietary administration. As the literature makes clear, the amount and the quality of BC produced, as well as its mechanical properties, are strain dependent traits and they may change on the basis of the carbon sources consumed (Zhong et al, 2013; Fang and Catchmark, 2015; Valera et al, 2015; Molina-Ramírez et al, 2017; Chen et al, 2018; Wang et al, 2018). In addition, pH, temperature and protocols of cultivation are environmental factors affecting BC production (Thorat and Dastager, 2018; Volova et al, 2018).…”

Bacterial Nanocellulose—A Biobased Polymer for Active and Intelligent Food Packaging Applications: Recent Advances and Developments

“…However, the main and the most efficient, as well as widely investigated, producers of BNC include Gram-negative, aerobic bacteria belonging to the Komagataeibacter genus [ 9 , 10 ]. These acetic acid bacteria are capable of metabolizing various carbon sources, such as glucose, fructose, mannitol, xylose, glycerol, dihydroxyacetone, or dicarboxylic acids into linear β-(1–4)-glucan chains and then, finally, extrude them through multiple pores located in their cytoplasmic membrane [ 4 , 11 ]. The chemical properties of bionanocellulose are, therefore, primarily associated with the construction of a repeating unit—cellobiose, which contains three free hydroxyl groups in positions C2 and C3 (secondary alcohols) and C6 (primary alcohol).…”

“…Due to their presence, BNC possesses a chemically reactive surface and relatively easily undergoes etherification, esterification, and acylation reactions. Additionally, microbial cellulose is a non-toxic and naturally porous biomaterial, which exhibits unique properties including remarkable biocompatibility, biodegradability, strong hydration, and excellent water-holding capacity (over 100 times of its own weight) [ 6 , 11 ]. The fibrillated network of the BNC results in very good mechanical properties, such as high elasticity (Young modulus of 15–18 GPa) and tensile strength, which places this material in a very high position over other natural polymers [ 4 ].…”