Efficient preparation of phytase from genetically modified Pichia pastoris in immobilised fermentation biofilms adsorbed on surface-modified cotton fibres

Biofilm-Based Biocatalysis for Galactooligosaccharides Production by the Surface Display of β-Galactosidase in Pichia pastoris

“…Immobilized cotton fiber material was selected as the carrier [ 21 ]. Immobilized cells and free cells catalyzed 500 g/L of lactose at 40 °C.…”

“…Based on this, some microorganisms such as Clostridium acetobutylicum , Escherichia coli, and Saccharomyces cerevisiae were used for immobilized batch or continuous (repeated-batch) fermentation effectively [ 15 , 16 , 17 , 18 , 19 , 20 ]. More specifically, we aimed to understand the effects of cell wall proteins, adhesion factors, and signaling molecules on biofilms [ 21 , 22 ]. For example, we previously identified the biofilm-related gene PAS_chr1-3_0226 (Gene ID: 8196458) in P. pastoris , which encodes a GPI protein with high homology to GAS1p in S. cerevisiae [ 23 ], that was anchored to the cell surface and could counteract intracellular pressure and maintain normal cell morphology [ 24 ].…”

Recent Advancements and Strategies of Improving CO2 Utilization Efficiency in Bio-Succinic Acid Production

“…Biofilm formation proceeds as a developmental process with distinct stages: "initial adhesion", where microorganisms bind to carrier surfaces through cell-surface-associated adhesins; "early biofilm formation", where they begin to divide and produce EPS (which enhances adhesion) and the forming matrix embeds the cells; "biofilm maturation", where the three-dimensional development of the matrix provides a multifunctional and protective scaffold, and cells in an established biofilm are glued together by the EPS (which resists mechanical stresses and detachment of the community from the surface of the substrate); and finally "dispersal", where some cells leave the biofilm to disperse into the bulk fluid [92]. Compared with the traditional fermentation by free cells, biofilm fermentation has the advantages of strong resistance to the harsh environment, high yield and continuous fermentation, and it is conducive to improving the fermentation performance [93]. Zhuang et al [94] found that the bacteria converted carbon sources into organic acids in the first step of ABE fermentation, which reduced the pH of the fermentation broth and acted as a stress on the bacteria.…”

“…Chen et al [97] reported that A. succinogenes CCTCC M2012036 was immobilized on positively charged polypropylene microfiber membranes, which could immobilize more cells through electrostatic interaction; the yield and productivity of SA achieved 0.82 g•g −1 and 1.04 g•L −1 •h −1 in this microfiber membrane bioreactor. Ding et al [93] modified cotton fiber with succinic anhydride; the cotton fiber surface roughness increased, and the decrease in hydrophilic groups and negative charge on the surface enabled cotton-succinic anhydride to absorb more cells. It was reported that a packed-bed biofilm reactor filled with Tygon support was constructed for continuous SA fermentation by A. succinogenes.…”

Reversible Adsorption and Detachment of Saccharomyces cerevisiae on Thermoresponsive Poly(N-isopropylacrylamide)-Grafted Fibers for Continuous Immobilized Fermentation

“…For the thermoresponsive PNIPAM-CF, the biofilm was removed by reducing the fermentation temperature while ultrasound was employed to strip the biofilm from CF. As depicted in Figure 8b, although ultrasound was one of the effective methods to remove the biofilm, 47 it was found that the removal efficiency of ultrasound on the biofilm was not ideal. As a striking contrast, because of the high removal efficiency of PNIPAM-CF for the biofilm, PNIPAM-CF could still show a similar trend from the first use (Figure 5a) until the third time.…”