Effective application of immobilized second generation industrial Saccharomyces cerevisiae strain on Consolidated Bioprocessing

N Biotechnol. 2023 Oct 30:S1871-6784(23)00062-6. doi: 10.1016/j.nbt.2023.10.011. Online ahead of print.ABSTRACTIntegrated bioprocessing strategies can facilitate ethanol production from both cellulose and hemicellulose fractions of lignocellulosic biomass. Consolidated bioprocessing (CBP) is an approach that combines enzyme production, biomass hydrolysis and sugar fermentation in a single step. However, technologies that propose the use of microorganisms together with solid biomass present the difficulty of the recovery and reuse of the biocatalyst, which can be overcome by cell immobilization. In this regard, this work applied immobilized cells of AC14 yeast, a recombinant yeast that secretes 7 hydrolytic enzymes, in the CBP process in a successful proof-of-concept for the enzyme access to the substrate polymers. The most appropriate cell load for CBP studies under the conditions studied with immobilized cells was selected among three optical densities (OD) 10, 55 and 100. These experiments were performed with free cells to ensure that the results were not biased by mass limitations effects. OD 10 achieved 100% of the sugar consumption and the higher specific production of enzymes, being selected for further studies. Diffusional effects were observed with immobilized cells under static conditions. However, mass transfer limitations were mitigated under agitation, with an 18.5% increase in substrate consumption rate (from 2.7 to 3.5g/L/h), reaching the same substrate uptake r...

Source: New Biotechnology - November 1, 2023 Category: Biotechnology Authors: Marcio D N Ramos Juliana P Sandri Arne Claes Bruna T Carvalho Johan M Thevelein Teresa C Zangirolami Thais S Milessi Source Type: research