Coffee processing environment harbours different microbiota of fungi and bacteria, some of which are of great economic value. This
study isolated, screened and identified indigenous yeast associated with ethanol production potential in coffee processing
environments of Mbinga in Ruvuma region and Hai in Kilimanjaro region using standard procedures. Yeast identification was done
by amplification and sequencing D1/D2 domain of the gene 26S rDNA. A total of 21 yeast isolates were obtained from both sites
and only 8 of them were able to ferment glucose. All 9 isolates fermented coffee pulp waste to ethanol at varying levels. Highest
ethanol production was observed by isolate M4, which produced 3% (v/v) ethanol, followed by PDA4MB (2.8% v/v), PDA3 (2.6%
v/v) and the least was by M2 which produced only 1.1% (v/v).Three isolates showed good attribute to ethanol production (2.76 to
3.56% v/v) even after an addition of higher sugar concentrations to coffee pulp waste. The basic local alignment search tool (BLAST)
and phylogenetic analysis revealed the identity of the yeasts as Pichia kudriavzevii, Issatchenkia orientalis, Clavispora lusitaniae,
Pichia guilliermondii, and Pichia anomala, all of them known to be associated with ethanol fermentation. Their attributes towards
ethanol fermentation are taken to be potential for further investigation for bioethanol production.
World Bank project C1A 3.3 “Industrial bioconversion of selected Tanzanian crops and residues into value added products using
biotechnology”