SJIF IMPACT FACTOR: 4.183 CRDEEPJournals International Journal of Environmental Sciences Muruke et. al., Vol. 3 No.4 ISSN: 2277-1948 255 Online version available at: www.crdeep.com International Journal of Environmental Sciences Vol. 3 No. 4. 2014. Pp. 255-262 ©Copyright by CRDEEP. All Rights Reserved Full Length Research Paper Optimization of Fermentation Parameters for Production of Ethanol from Coffee Pulp Waste Using Pichia anomala M4 Yeast Isolated from Coffee Environment in Tanzania Said Hamadi, Masoud H. Muruke 1 and Ken M.M. Hosea Department of Molecular Biology and Biotechnology, College of Natural and Applied Sciences, Uvumbuzi Road, University of Dar es Salaam, P.O. Box 35179, Dar es Salaam, Tanzania. *Corresponding Author: Masoud H. Muruke Abstract 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 0 C 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. Key words: Coffee pulp waste, Ethanol, Optimization, Yeast. Introduction Considerable attention has been focused on biomass as an alternative energy biosource due to an increasing demand over fossil fuels. The increasing in air pollution from exhaust emissions (Koç et al., 2009), depletion of the worldwide fossil fuel reserve (Festel, 2008) and continuously rising petroleum costs (Ayhan, 2005) has lead to technological innovation on alternative renewable fuel production (Festel, 2008) and in engines technology (Celik, 2008). Agro-waste raw materials could substantially reduce the cost of bioethanol production (Mutreja et al., 2011). In this context, some researchers have conducted studies on the use of banana and pineapple wastes (Itelima et al., 2013(a) ), cassava and sweet potato peels (Oyeleke et al., 2012), pawpaw waste (Dhanaseli and Balasubramanian, 2014), corn cobs (Itelima et al., 2013(b), Zakpaa et al., 2009) and coffee waste (Gouvea et al., 2009). Tanzania is producing a huge quantity of approximately 143,259 metric tons of coffee processing industrial wastes and effluents (TCB, 2010). Usually these wastes are disposed with appreciable amount of sugars (Chanakya and De Alwis, 2004) and hence favor quick growth of microorganisms (Roussos et al., 1995) which might be unattractive to the environment. Nevertheless, these waste may serve as an important biotechnological feedstock and have previously been used for production of mushroom from coffee leaves, spent ground and coffee husk (Pandey et al., 2000), methane gas from coffee pulp (Kivaisi et al., 1996, Boopathy, 1988) and ethanol from coffee husks (Gouvea et al., 2009). Efficient use of coffee waste however, is problematic due to the presence of caffeine and polyphenols (Zuluaga, 1989, Roussos et al., 1995) and therefore optimal parameters for yeast fermentation processes to achieve high yield would be important. The potential of coffee pulp waste (CWP) produced in Tanzania for ethanol production using locally isolated yeast strains has not been evaluated before. The present study therefore, focuses on development of optimal conditions for ethanol fermentation by a locally isolated yeast strain through optimization of key parameters such as temperature, pH and supplementation with soy flour.The investigation reported in this study was focused on the effect of some fermentation parameters and supplementation in the fermentation of CPW by indigenous yeast identified as Pichiaanomala M4. This fungi is a non-saccharomyces yeast associated with wine fermentation (Spagna et al., 2002, Naumov et al., 2001) and has previously been used for bioethanol production from shatian pummelo peels in China (Tao et al., 2011). Materials and Methods Coffee pulp waste collection Coffee pulp waste was collected from Mbinga in Ruvuma and Moshi in Kilimanjaro, the regions where there is high production of coffee in Tanzania. In both regions Coffee arabica is mostly grown and coffee processing is done using wet method. The samples were collected at industrial sites from the fermentation tanks, frozen, kept in ice box and transported to the laboratory at the Department of Molecular Biology and Biotechnology, University of Dar es salaam. To avoid microbial contamination, CPW was sterilized at 121.1 o C for 15 min, cooled to room temperature (28- 32 0 C) and then kept in the fridge at 4 o C before use.