Effects of Inhibitors Generated by Dilute Phosphoric Acid Plus Steam-Exploded Poplar on Saccharomyces cerevisiae Growth

Abstract

The pretreatment of lignocellulosic biomass is important for efficient bioethanol conversion, but causes undesirable by-products that inhibit microbial growth, conversely affecting the bioconversion efficiency. In this study, the main inhibitors derived from dilute phosphoric acid plus steam-exploded poplar wood were identified as 0.22 g/L furfural, 3.63 g/L acetic acid, 0.08 g/L syringaldehyde, etc., indicating the green nature and low toxicity of the pretreatment process. The effects of the three typical inhibitors (furfural, acetic acid, and syringaldehyde) on Saccharomyces cerevisiae 1517RM growth were analyzed and shown to prolong the lag phase of microbial growth to different degrees. In all the inhibitor groups, the ergosterol secretion was boosted, indicating low cell membrane fluidity and robustness of the strain to an adverse environment. The cell electronegativity and morphology of S. cerevisiae 1517RM also changed under different growth conditions, which was helpful for monitoring the physicochemical properties of cells. Furfural, acetic acid, and syringaldehyde had a synergistic effect on each other, providing an important reference to improving the subsequent ethanol fermentation process.

Effect of pepper and cabbage planting on loess of Guyuan region of China on microbial diversity

“…This may be related to root characteristic of cabbage and pepper. As tap root system, the roots of cabbage and pepper can reach to deeper soil layer, thereby inhibiting or promoting the growth of some microorganism by secreting some inhibitors (Yeoung, et al 2002;Sharma, et al 2011), such as proteinaceous xylanase inhibitors (Chmelova, et al 2019), furfural, acetic acid, and syringaldehyde (Wang, et al 2022). Our data speculated that pepper and cabbage could improve soil quality by regulating soil microbial community.…”

Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors

“…Acid hydrolysis is one of the most common pretreatment methods, mainly relying on inorganic acids (such as sulfuric acid, phosphoric acid, or nitric acid) or organic acids (such as formic acid, maleic acid, or oxalic acid) [61,68,89,90]. Initially, acid molecules cause the breakdown of the glucosidic bonds between cellulose and hemicelluloses, and hydrolyze hemicelluloses partially or completely into monosaccharides or smaller oligosaccharides.…”