A Study of effect of different agricultural conditions on production of enzyme mannanase from fungal isolate Lentinula edodes

Shiitake mushroom,scientically known as Lentinula edodes, is a white-rot fungus with significant medical and industrial importance ,particularly for being source of mannanase enzymes. Both natural and synthetic mannans are used in its mannan form, which contains substances that stimulate use of β-mannanase in industrial applications due to its multifaceted properties . An isolate of Lentinula edodes was obtained from Al-Waduk Company for Fungal Production and Cultivation in Baghdad. Preliminary screening revealed its ability to produce mannanase enzyme, indicated by a clear zone of hydrolysis measuring 14.6mm in diameter. This isolated was cultivated on LBG medium, yielding an enzyme activity of 2.38 units/ml. Cultivation studies demonstrated that submerged fermentation reported highest enzyme activity after 9 days of incubation, reaching 2.94 units/ml. this was determined to be the optimal incubation period under the following conditions: 30oC , LBG as carbon source, 0.4% yeast extract as nitrogen source, pH 6, and an agitation rate of 150 rpm. Additionally, supplementation of culture medium with acacia seeds as a natural compound AL2O3 significantly enhanced enzyme production.