 Corresponding author: Gimba A.Y Department of biological Sciences, Niger State Polytechnic Zungeru, Nigeria. Copyright © 2021 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. Isolation and optimization of the fermentation condition of cellulolytic microbial isolates from cassava waste water Yaya A. Gimba 1, * , Abubakar Idris 1 , Abdullahi Hassan 1 and Opeyemi N. Hassan 2 1 Department of Biological Sciences, Niger State Polytechnic Zungeru, Nigeria 2 Centre International Universitaire Des Meilleurs (C.I.U.M), Bestower International University Seme-Podji-Republique Du Benin. GSC Biological and Pharmaceutical Sciences, 2021, 14(01), 011–017 Publication history: Received on 05 December 2020; revised on 03 January 2021; accepted on 05 January 2021 Article DOI: https://doi.org/10.30574/gscbps.2021.14.1.0421 Abstract The study was conducted to isolate and identify cellulose producing microorganisms from cassava waste water. Cassava waste water sample was obtained from a cassava processing factory at Lokogoma town in Wushishi Local government area of Niger State. The microorganisms were isolated, identified and counted by standard microbiological methods. The mean bacteria count ranges from 6.8 x 10 3 cfu/mL -1 to 2.1 x 10 3 cfu/mL -1 while the fungi count ranges from 3.2 x 10 3 cfu/mL -1 to 1.2 x 10 3 cfu/mL -1 . A total of eight (8) bacterial; Staphylococcus aureus, Bacillus anthrax, Bacillus subtilis, Escherichia coli, Klebsilla sp, Bacillus megaterus, Staph. Epidermidis and Pseudomonas aeruginosa, and six (6) fungi; Saccharomyce serivicea, Aspergillus niger, Penecillium sp., Muccor sp., Aspergilus flavus and Aspergilus fumigetus isolates were identified in the waste water. Among these organism, the best cellulase activity was recorded for Bacillus subtilis (10.39 x 10 -4 mg/ml/sec) and Aspergillus niger (11.21 x 10 -4 mg/ml/sec). However, maximum activity was obtained at pH ranges from 3 ~ 9, temperature ranges from 30 o C ~ 80 o C and substrate concentrations ranges from 1.5% ~3.0%. In conclusion, cassava processing water regarded as waste water could be an alternative source of microorganisms capable of producing cellulase enzyme for industrial purposes. Keywords: Cassava waste water; Microbial isolate; Cellulase; Optimization 1. Introduction Biomolecules derived from natural resources are playing a major role in manufacturing products needed for daily use [1]. Enzymes are one of those molecules that are globally recognized for their multifarious applications in industries. For instance, their utility in brewing, dairy products, detergents, food and feed, pharmaceutical production, and paper and pulp industry is huge. One of those most widely used enzymes is cellulase [2]. According to recent global cellulase market analysis reports, the demand for this enzyme is exponentially increasing. Cellulose the substrate of cellulase is the most abundant biological compound on terrestrial and aquatic ecosystem, and is the main component of plant biomass [3]. It is the dominant waste material from agricultural industry in the form of stalks, stems and husk, and there has been great interest in utilizing cellulose as an energy resource and feed [4]. The cellulose is composed of D-glucose units linked together to form linear chain via ß-1, 4-glycosidic linkages [5]. Cellulase catalyses the hydrolysis of cellulose, it is composed of endoglucanase and exoglucanases including cellobiohydrolases and β-glucosidase. The enzyme breaks β-1,4-linkages in cellulose polymer to release sugar subunits such as glucose. This notion is applied in industries either cellulose is utilized as a raw material or cellulose degradation is a must [6].