Over the last few years orange mesocarp (O.M), a waste product from citrus processing factories and farmers is partly used for animal feed. A larger part of the citrus waste produced about 66 million tons annually is still being discarded to nature causing environmental problem. O.M feed stock produced glucose syrup using Trichoderma reesei. O.M was subjected to 3-distinct alkaline pre-treatment methods; NaOH, Ca(OH)2 and the ammonia Steeping method. Ca(OH)2 produced highest 3.4 mmol/L glucose. Enzymatic Hydrolysis of O.M were affected by: particle size, temperature, medium pH and substrate concentration. Optimum weight loss was 70% at 25 minutes soaking time. Optimum temperature was 37oC, optimum pH was 4.5 and optimum particle size was (100-150)mim. Trichoderma reesei, a thermophilic fungus was observed to be favourable in the hydrolysis of O.M-cellulose. The reaction was a simple first order kinetics with reaction rate constant; k as 0.238 and n equals to 1. This book therefore, provides a new inroad of success to researchers in Chemical, Biochemical Engineering, Biotechnology, Biochemistry, Microbiology e.t.c. in their research both at post graduate and under graduate level