ABSTRACT

 This study was done to isolate and characterize palm (Elaeis guineensis and Raphia hookeri) wine base yeast for industrial utility. Palm wines used for this study were collected from Ikwuano and Isiala Ngwa Local Government Areas both in Abia state. Evaluation of the physicochemical characteristics of the palm wine, biological, genetics, and biochemical properties ofthe isolated yeast from palm wine sourced from palm wine street vendors and wine tappers respectively were carried out. Yeast samples were isolated through serial dilution and further sub-culturing ofidentified yeast cells in a cultured plate. After macroscopic, microscopic, and molecular identification ofthe yeast cells two randomly selected yeast isolates from the palm wine were used for the production of ethanol and bread with industrial yeast (Control). From the result, acetic levels increased to 0.05 % after 48 hours. The effect ofthe difference in the plant, time, and interaction was not significant (P > 0.05). Ethanol levels increased from 0.00 % to 4.33 %. The difference in plant source was not significant (P > 0.05). However, the difference in time was significant (P < 0.05). On pH, Sugar, lactic acid, and Acetic acid levels. pH, Sugar, Ethanol, and Lactic acid levels of raffia palm had a correlation with each other except Acetic acid. The isolated yeast cells showed oval-shaped budded cells appearing bluish and creamy-colored mucous colonies on PDA plates. Nucleic acid levels of Nkwri isolate was 203.9 ng/pl, Ngwo isolate had 219.9 ng/pl. Sugar utilization test was positive for glucose, maltose, sucrose, galactose and raffinose. Nkwu isolates showed 86 %, Ngwo isolate showed 82%, and control showed 90 % flocculence ability respectively. In the main study, the phytochemical properties of the sampled palm wine varied significantly (P < 0.05) for pH, titratable acidity, lactic acid, sugar, ethanol, and acetic acid. The six isolated samples were Oval-shaped bluish cells and Creamycolored mold colonies on PDA plates. Differences in pH, temperature and alcohol levels showed varying significance (P < 0.05) over time and isolates. The yeast isolates were amplified at 650 bp. DNA sequences of the yeast isolates showed that the organisms were all Saccharomyces cerevisiae giving the output of the basic local alignment search tool (BLAST) with similarity levels ranging from 83.82 % to 94.94 %. The ethanol production increased from 2.93 - 5.55 %, 1.98 — 4.90 %, and 2.83 — 5.10 % for control, Ngwo isolate and Nkwu isolate respectively. The volume, weight of the bread produced was the lowest for the control yeast isolate. The general acceptance of bread from the palm wine yeast isolates was judged liked extremely. In conclusion, the vegetative structure ofthe isolated yeast cells when matched with those available in the fungi atlas confirmed it as Saccharomyces species. Similarly, the ability ofthe yeast DNA sample to amplify with ITS 3 and 4 further confirms the Saccharomyces species. Hence industrialists aie advised to adopt yeast isolated from palm wine for bread making and wine or alcohol production.