Kluyveromyces marxianus MTCC 1389 Augments Multi-stress Tolerance After Adaptation to Ethanol Stress.

Pal, Upma; Pal, Sumit; Vij, Shilpa

During fermentation, yeast cells undergo various stresses that inhibit cell growth and ethanol production. Therefore, the ability to tolerate multiple stresses during fermentation is one of the important characteristics for yeast cells that can be used for commercial ethanol production. In the present study, we evaluated the multi-stress tolerance of parent and ethanol adapted Kluyveromyces marxianus MTCC1389 and their relative gene expression analysis. Multi-stress tolerance was confirmed by determining its cell viability, growth, and spot assay under oxidative, osmotic, thermal, and ethanol stress. During oxidative (0.8% H2O2) and osmotic stress (2 M NaCl), there was significant cell viability of 90% and 50%, respectively, by adapted strain. On the other hand, under 45 °C of thermal stress, the adapted strain was 80% viable while the parent strain was 60%. In gene expression analysis, the ethanol stress responsive gene ETP1 was significantly upregulated by 3.5 folds, the osmotic stress gene SLN1 was expressed by 3 folds, and the thermal stress responsive gene MSN2 was expressed by 7 folds. This study shows adaptive evolution for ethanol stress can develop other stress tolerances by changing relative gene expression of osmotic, oxidative, and thermal stress responsive genes.

KLUYVEROMYCES marxianus; BIOLOGICAL evolution; ETHANOL; THERMAL stresses; GENE expression; CELL survival; OSMOTIC pressure

Indian Journal of Microbiology, 2023, Vol 63, Issue 4, p483

0046-8991

Academic Journal

10.1007/s12088-023-01102-8