Biosystems Diversity, Journal Year: 2024, Volume and Issue: 32(1), P. 45 - 59

Published: Jan. 7, 2024

The second generation (2G) or cellulosic ethanol can help with diversification of the use fossil energy sources. However, as bioconversion plant waste into 2G bioethanol requires expensive additional steps pre-treatment/hydrolysis lignocellulosic materials, and this technology has not yet reached technological readiness level which would allow it to be scaled-up, process needs more interdisciplinary comprehensive studies. This work was aimed at experimental study a full cycle successive processes pre-treatment/saccharification using cellulolytic enzymes filamentous fungi fermentation obtained syrups by xylose-fermenting yeast, selected natural microorganisms for fungal-based agricultural ethanol. Using Plackett-Burman Box-Behnken methods mathematical statistics, optimal conditions pre-treatment enzymatic hydrolysis wheat straw hemi- multi-enzyme complex fungal strain Talaromyces funiculosus UCM F-16795 were established: microwave-assisted alkali sodium hydroxide (NaOH) solutions (concentration range 4.6–4.8%), saccharification medium pH 4, temperature 40 °С, duration 18 hours, dilution culture liquid buffer solution 1:1. total microwave irradiation 1.2 kJ ratio substrate/enzyme 100 mg/1 mL used. Under optimized conditions, hydrolysates contained 5.0–7.5 g/L reducing sugars, which, according HPLC assessment, 0.7–1.0 glucose, 2.2–2.9 xylose 0.7–0.8 cellobiose. We used yeast in mixtures most important monosaccharides hydrolysates, concentration relevant us during substrates T. enzymes. Based on sequencing phylogenetic analysis, Y-2810 confirmed Scheffersomyces stipitis; its nucleotide sequences ITS region 28S gene rDNA deposited GenBank under accession numbers OP931914 OP931915, respectively. ethanologenic S. stipitis studied design, assessing gas chromatography-mass spectrometry. Yeast static microaerophilic showed 1.5 times higher rate production 1.7 greater efficiency ethanologenesis per biomass than submerged cultivation. Optimization resulted maximum mixture being 11.30 ± 0.36 ethanol, values factors: 30 xylose, 5.5 glucose cultivation days. It revealed that tested concentrations did significantly affect xylose-fermentation non-competitive inhibition transport cells occur. demonstrated potential based strains optimization all steps.

Language: Английский