Inhibition of alternative respiration system of Scheffersomyces stipitis and effect on glucose or xylose fermentation

Abstract

Scheffersomyces stipitis is a Crabtree-negative pentose fermenting yeast, which shows a complex respiratory system involving a cytochrome and an alternative salicylhydroxamic acid (SHAM)-sensitive respiration mechanism that is poorly understood. This work aimed to investigate the role of the antimycin A (AA) sensitive respiration and SHAM-sensitive respiration in the metabolism of xylose and glucose by S. stipitis, upon different agitation conditions. Inhibition of the SHAM-sensitive respiration caused a significant (p < 0.05) decrease in glycolytic flux and oxygen consumption when using glucose and xylose under agitation conditions, but without agitation, only a mild reduction was observed. The combination of SHAM and AA abolished respiration, depleting the glycolytic flux using both carbon sources tested, leading to increased ethanol production of 21.05 g/L at 250 rpm for 0.5 M glucose, and 8.3 g/L ethanol using xylose. In contrast, inhibition of only the AA-sensitive respiration, caused increased ethanol production to 30 g/L using 0.5 M glucose at 250 rpm, and 11.3 g/L from 0.5 M xylose without agitation. Results showed that ethanol production can be induced by respiration inhibition, but the active role of SHAM-sensitive respiration should be considered to investigate better conditions to increase and optimize yields.

Influence of furfural and acetic acid on bioenergetics of Scheffersomyces stipitis

“…Interestingly, when the bc1 complex ofS. stipitis was inhibited, evaluation of the alternative respiration system showed a similar lag phase delay (Granados-Arvizu et al, 2021). The mixture of furfural and acetic acid resulted in growth inhibition at 0.2% and 0.3 % v/v treatments, but at 0.1% v/v, the yeast growth was almost like the control (Fig.…”

“…The impact of furfural, acetic acid, or their mixture on S. stipitis growth kinetics was estimated following Granados-Arvizu et al (2021). The inhibitors tested were furfural (Sigma-Aldrich) at 0.1%, 0.2% or 0.3% (v/v), acetic acid (J.T.…”

Engineering Scheffersomyces segobiensis for palmitoleic acid‐rich lipid production

“…Genome analysis displayed that S. segobiensis DSM27193 is closely related to Scheffersomyces stipites , which is a Crabtree negative yeast capable of fermenting a wide range of sugars to ethanol (Papini et al, 2012 ; Zhou, Xu, et al, 2021 ). Flux states of S. stipitis metabolism declared that increasing dissolved oxygen (DO) levels led to a decrease in ethanol synthesis (Granados‐Arvizu et al, 2021 ; Unrean & Nguyen, 2012 ). Previous attempts to improve DO levels through regulation of agitation and aeration rates during fermentation were indeed conducive to decrease ethanol accumulation (Zhou et al, 2023 ).…”