초록
<P><B>Abstract</B></P> <P>We investigated the yeast species associated with rotting wood samples obtained from Brazilian ecosystems, with a special focus on cellobiose-fermenting species. About 647 yeast strains were isolated from rotting wood samples collected from the areas of Atlantic rainforest, Cerrado, and Amazonian forest. Eighty-six known species and 47 novel species of yeasts were isolated. <I>Candida boidinii, Cyberlindnera subsufficiens, Meyerozyma guilliermondii, Schwanniomyces polymorphus, Candida natalensis</I>, and <I>Debaryomyces hansenii</I> were the most frequently isolated species. Among the cellobiose-fermenting yeasts, 14 known and three novel yeast species were identified. <I>Scheffersomyces queiroziae, Sc. amazonensis, Yamadazyma</I> sp.1, <I>Hanseniaspora opuntiae</I>, <I>C. jaroonii</I>, and <I>Candida tammaniensi</I>s were the main ethanol-producing yeasts. These species also produced an intracellular β-glucosidase responsible for cellobiose hydrolysis. In fermentation assays using a culture medium containing 50 g L<SUP>−1</SUP> cellobiose, ethanol production was observed in all cases; <I>Sc. queiroziae</I> and <I>Sc. amazonensis</I> showed the highest yield, efficiency, and productivity. <I>Candida jaroonii</I> and <I>Yamadazyma</I> sp.1 strains also showed high efficiency in cellobiose fermentation, while <I>C. tammaniensis</I> and <I>H. opuntiae</I> strains produced low amounts of ethanol. This study shows the potential of rotting wood samples from Brazilian ecosystems as a source of yeasts, including new species as well as those with promising biotechnological properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Eighty-six known and 47 novel yeast species were isolated in this study. </LI> <LI> <I>Scheffersomyces</I> species includes excellent cellobiose fermenters. </LI> <LI> <I>Yamadazyma</I> species are promising yeasts for use in cellobiose fermentation. </LI> <LI> In the yeasts studied, cellobiose is metabolised by an intracellular β-glucosidase. </LI> </UL> </P>