Optimization of Fermentation Parameters for Production of Ethanol from Coffee Pulp Waste Using Pichia anomala M4 Yeast Isolated from Coffee Environment in Tanzania

Coffee pulp waste (CPW), an abundant agro-waste available in Tanzania was studied as a potential substrate for bioethanol production. Selected yeast Pichia anomala M4 previously isolated from coffee environment was tested against three fermentation parameters namely pH, temperature and soy flour supplementation. Maximum ethanol of 4.7% (v/v) and 4.07% was produced at an optimum pH 4.5 and temperature of 30 0C respectively. There was a significant increase (ANOVA, P˂0.05) in ethanol production on addition of soy flour as a supplement with a maximum yield of 6.04% (v/v) ethanol at a soy flour concentration of 2.0% g/l. A slight increase on ethanol production (6.3% v/v) was recorded when all the three parameters were put together. Appreciable amount of sugar content (8.2 g/l) found in CWP and significant levels of ethanol produced by yeast from the agricultural waste, calls for more research on how best to utilize this untapped bioresource.