Characterization of the Putative Acylated Cellulose Synthase Operon in Komagataeibacter xylinus E25

Abstract

Bacterial cellulose is a natural polymer with an expanding array of applications. Because of this, the main cellulose producers of the Komagataeibacter genus have been extensively studied with the aim to increase its synthesis or to customize its physicochemical features. Up to now, the genetic studies in Komagataeibacter have focused on the first cellulose synthase operon (bcsI) encoding the main enzyme complex. However, the role of other accessory cellulose operons has been understudied. Here we aimed to fill this gap by performing a detailed analysis of the second cellulose synthase operon (bcsII), which is putatively linked with cellulose acylation. In this study we harnessed the genome sequence, gene expression and protein structure information of K. xylinus E25 and other Komagataeibacter species to discuss the probable features of bcsII and the biochemical function of its main protein products. The results of our study support the previous hypothesis that bcsII is involved in the synthesis of the acylated polymer and expand it by presenting the evidence that it may also function in the regulation of its attachment to the cell surface and to the crystalline cellulose fibers.

Bacterial Cellulose-Based Materials: A Perspective on Cardiovascular Tissue Engineering Applications

“…This technique with simplicity and rapidness can be deployed for synthesis of BC under mild conditions (Figure ). Recent studies have demonstrated the fabrication of BC-based functional biomaterials regulated at the molecular level through different mechanisms, including cellulose synthase operon ( bcsI ) as well as plasmid-based expression system. ,, …”

“…48 Recent studies have demonstrated the fabrication of BC-based functional biomaterials regulated at the molecular level through different mechanisms, including cellulose synthase operon (bcsI) as well as plasmid-based expression system. 20,53,54 Several studies have focused on the biomedical applications, properties, and fabrication methods of BC-based materials. 55−57 However, the present review aims to provide a great insight into promising green nanotechnology approaches in cardiovascular TE, particularly the most recent developments pertaining to the cardiovascular TE applications of BC-based materials.…”

WssI from the Gram-negative bacterial cellulose synthase is an O-acetyltransferase that acts on cello-oligomers with several acetyl donor substrates

“…For example, the colonization of biotic and abiotic surfaces by some opportunistic human and plant pathogens has been linked to the production of biofilms composed of the β-(1→4)-linked d -glucose polymer, cellulose. A growing list of bacteria, including Acetobacter ( 11 , 12 ), Clostridium (previously Sarcina ) ( 6 , 11 ), Bordetella ( 13 ), Komagataeibacter ( 13 ), Rhizobium ( 11 ), Agrobacterium ( 11 ), Cronobacter ( 5 ), Salmonella ( 14 ), Escherichia coli ( 15 , 16 , 17 ), and Pseudomonas ( 18 ), are now known to produce cellulose and are of clinical and economical importance. Of the organisms on this list, E. coli and Salmonella enterica are the most extensively studied with respect to bacterial cellulose biosynthesis and have served as model organisms for understanding the synthesis and export of the polymer ( 3 , 16 , 17 , 19 ).…”

“…WssD is a predicted glycoside hydrolase, like BcsZ from E. coli and CcsZ from Clostridium difficile , and is proposed to cleave the growing polymer to allow release from the cell into the biofilm matrix ( 46 , 50 , 53 , 54 ). While the downstream wssFGHI genes (or homologs thereof) are beginning to be noted with cellulose synthase systems, the biochemical activity of the individual gene products remain uncharacterized ( 12 , 55 ). However, these gene products share homology to algX/FIJ , which contribute to acetylation of alginate in P. aeruginosa , so wssFGHI are likewise predicted to encode for proteins that decorate the cellulose polymer with acetyl groups in an analogous fashion.…”

“…In separate studies, the bcsII (type 2) operon in Komoagataeibacter xylinus was similarly shown to be involved in the colonization of the air–liquid interface, and sequence comparisons suggest that this operon also possesses genes ( i.e. , labeled bcsXYZ ) that influence the levels of cellulose acylation ( 12 , 55 ). These combined results support that WssFGHI work in a concerted fashion to acetylate the cellulose polymers, which promotes biofilm/colony spreading, adherence to surfaces, and maintenance of a robust biofilm that, at least in P. fluorescens , contributes to virulence ( 18 , 46 , 48 ).…”