“Deceived” Concentrated Immobilized Cells as Biocatalyst for Intensive Bacterial Cellulose Production from Various Sources

Abstract

Abstract:A new biocatalyst in the form of Komagataeibacter xylinum B-12429 cells immobilized in poly(vinyl alcohol) cryogel for production of bacterial cellulose was demonstrated. Normally, the increased bacteria concentration causes an enlarged bacterial cellulose synthesis while cells push the polysaccharide out to pack themselves into this polymer and go into a stasis. Immobilization of cells into the poly(vinyl alcohol) cryogel allowed "deceiving" them: bacteria producing cellulose pushed it out, which further passed through the pores of cryogel matrix and was accumulated in the medium while not covering the cells; hence, the latter were deprived of a possible transition to inactivity and worked on the synthesis of bacterial cellulose even more actively. The repeated use of immobilized cells retaining 100% of their metabolic activity for at least 10 working cycles (60 days) was performed. The immobilized cells produce bacterial cellulose with crystallinity and porosity similar to polysaccharide of free cells, but having improved stiffness and tensile strength. Various media containing sugars and glycerol, based on hydrolysates of renewable biomass sources (aspen, Jerusalem artichoke, rice straw, microalgae) were successfully applied for bacterial cellulose production by immobilized cells, and the level of polysaccharide accumulation was 1.3-1.8-times greater than suspended cells could produce.

Prospective Approach to the Anaerobic Bioconversion of Benzo- and Dibenzothiophene Sulfones to Sulfide

“…This was confirmed by the fact that, in the third cycle of cell usage, the same characteristics of methanogenesis were observed as in the second cycle. The observed effects were associated with the improvement of the adaptation of bacterial immobilized biocatalysts to the culture conditions, as observed in other studies [13,15,16,17].…”

“…One of the advantages of using cells immobilized in a PVA cryogel demonstrated in this process is the possibility of the repeated use of these cells without losing efficacy, which was previously demonstrated only for other cells [13,15,16,17]. The results obtained open up prospects for a more in-depth study of the proposed approaches and may be useful to researchers engaged in the study of issues of environmentally safe and cost-effective waste treatment with the production of commercially significant products.…”

Immobilized Luminescent Bacteria for the Detection of Mycotoxins under Discrete and Flow-Through Conditions

“…In this work, P. phosphoreum cells immobilized in PVA cryogel were used to evaluate the concentration of Zearalenone in the reaction medium before and after its hydrolytic treatment with His 6 -OPH, which has lactonase activity [23,24]. As a control method for the determination of Zearalenone, an ELISA method was used.…”

“…In general, PVA cryogel is a well-known nontoxic and chemically stable polymer matrix [15,16,17] successfully used for the immobilization of living cells of different microorganisms. It can be stored for a long time [18,19] and has been proven to be effective for various applications [20,21,22,23]. The immobilization of cells in the PVA cryogel can be achieved by the inclusion of the cells in the macroporous polymer matrix during the process of its cryoformation.…”

Immobilized Biocatalysts

“…The device enabled visualization of fluctuations in glucose and dopamine concentrations at a millisecond time scale. Komagataeibacter xylinum B-12429 cells immobilized in polyvinyl-alcohol cryogel turned out to be well suited for the production of bacterial crystalline cellulose from various renewable biomass sources as reported by Stepanov and Efremenko [43]. The cellulose passed through the pores of the cryogel matrix into the medium resulting in a continuous production.…”