High-affinity transport, cyanide-resistant respiration, and ethanol production under aerobiosis underlying efficient high glycerol consumption by Wickerhamomyces anomalus
Wickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cachaça (the Brazilian fermented sugarcane juice-derived Brazilian spirit) and has been shown to grow exceptionally well at high amounts of glycerol. This paramount residue from the biodiesel industry is a promising cheap carbon source for yeast biotechnology. The assessment of the physiological traits underlying the W. anomalus glycerol consumption ability in opposition to Saccharomyces cerevisiae is presented. A new WaStl1 concentrative glycerol-H+ symporter with twice the affinity of S. cerevisiae was identified. As in this yeast, WaSTL1 is repressed by glucose and derepressed/induced by glycerol but much more highly expressed. Moreover, LBCM1105 aerobically growing on glycerol was found to produce ethanol, providing a redox escape to compensate the redox imbalance at the level of cyanide-resistant respiration (CRR) and glycerol 3P shuttle. This work is critical for understanding the utilization of glycerol by non-Saccharomyces yeasts being indispensable to consider their industrial application feeding on biodiesel residue.This work was supported by grants from Fundacao de Capacitacao de Pessoal de Nivel Superior from the Ministry of Education-CAPES/Brazil (PNPD 2755/2011; PCF-PVE 021/2012), from FEDER through POFC-COMPETE and by FCT through strategic funding (UID/BIA/04050/2013), from Universidade Federal de Ouro Preto, and a research fellowship from Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq (Brazil) Process 304815/2012 (research grant) and Process 305135/2015-5 (research fellowship to R.L.B.). C.L. is supported by the strategic program UID/BIA/04050/2013 [POCI-01-0145-FEDER-007569] funded by national funds through the FCT I. P. and by the ERDF through the COMPETE2020-Programa Operacional Competitividade e (POCI). The AUXPE-PVES 1801/2012 (Process 23038.015294/2016-18) from Brazilian Government supported a grant of Visiting Professor to C.L. and a research fellowships to A.C.C. and to F.F.O
