A Study Of Palm-Wine Yeasts Associated With Felled Elaeis Guineensis Trees

Certain characteristic features of eight yeasts (Table 2) _ present in felled Elaeis guineensis Jacq and Elaeis puineensis Lisombe juice in Ghana have been established. The yeast isolates were found to be alcohol tolerant and exist in acid pH. Literature survey was carried out on general habitats, sampling, isolation, culturing, storage, classification and uses of yeasts. The survey was also extended to include palm-wine with special reference to Ghanaian palm-wine. Controlled tapping and sampling of the wine took three successive tapping periods. Two identified insects were familiarised with felled Elaeis tapping wells and wine as a result of their ° constant visits. Data obtained showed that by using varied media, both standard - YM agar - and improvised - PW agar, BW agar and 8W agar - a high number of yeasts species could be recovered from the fresh sap and fermentative types from the ripe sap. To the author's best knowledge, eight of the yeast isolates included five unreported species: C. tropicalis, C. valida, Sacch.. exiguus, Zygosacch. rouxii and P. oghmeri from Elaeis wine. P. ohmeri and Zygosacch. rouxii have not been associated with any other palm-—wine. Some tropical semi-ripe fruits and raw tubers were found to enhance vegetative and sexual growth of the yeast isolates. (i) Some of the yeasts could be explcited for industrial fermentation of certain sugars: fructose, glucose, maitose - the production of alcohol, production of milk proteolyses, formation of flavouring compounds, and assimilation of B vitamins as well as nitrogen. Sucrose was discovered the most diminished sugar in felled EFlaeis-wine for consumption. Fructose was also discovered and established as the major sugar contributing to the sweetness of the palm exudate. The palm juice obtained was confirmed highly buffered with acid pH 4.00 - 3.75. Firing technique was observed to hydrolyse complex sugars to utilizable ones. It was also observed to effect ripening and acceleration of the oozing of the exudate.