Isolation and characterization of ethanol-producing yeasts from fruits and tree barks.

AIMS

Isolation and identification of yeasts converting xylose to ethanol.

METHODS AND RESULTS

A total of 374 yeasts were isolated from a variety of rotten fruits and barks of trees. Out of these, 27 yeast strains were able to assimilate xylose and produce 0.12-0.38 g of ethanol per gram of xylose. Based on phylogenetic analysis of D1/D2 domain sequence of LSU (Large Subunit) rRNA gene and phenotypic characteristics the ethanol-producing strains were identified as member(s) of the genera Pichia, Candida, Kluyveromyces, Issatchenkia, Zygosacchraomyces, Clavispora, Debaryomyces, Metschnikowia, Rhodotorula and Cryptococcus.

CONCLUSION

Yeast strains producing ethanol from xylose have been isolated from a variety of rotten fruits and barks of trees and identified.

SIGNIFICANCE AND IMPACT OF THE STUDY

Environmental isolates of yeasts which could convert xylose to ethanol could form the basis for bio-fuel production and proper utilization of xylan rich agricultural and forest wastes.