An investigation of industrial wastes utilization as a nitrogen source on mannanase production

Microbial mannanases have become biotechnologically important since they target the hydrolysis of complex polysaccharides of plant tissues into simple molecules like manno-oligosaccharides and mannoses. They have found many applications in the food and feed technology, such as fruit juice clarification, fruit maceration. Production of value-added products by using low-cost sources have increasingly come into prominence. It is well known that major nutrients are carbon and nitrogen for a fermentation process. Medium are generally supplied from expensive sources such as ammonium nitrate, ammonium nitrite, yeast extract, and peptone. The aim of this study was to determine potential of some nitrogen sources which are economically appropriate on mannanase production by recombinant Aspergillus sojae using carob and glucose as carbon source. For this purpose, three of nitrogen sources of animal origin (meat-bone meal, fish meal and feather meal) and four vegetable sources (red lentil powder, cottonseed meal, maize zein, soybean protein), seven different materials were assayed. Various quantities of these materials (0.5%, 0.75%, 1.0%) were added to fermentation media. Enzyme activity results obtained from fermentations are given following: Red Lentil Powder(1%): 247.11 U/ml, Cottonseed Meal(1%): 315.75 U/ml, Maize Zein(1%): 228.17 U/ml, Soyabean Protein(0,75%): 525.93 U/ml, Meat-Bone Meal(0,75%): 597.31 U/ml, Feather Meal(1%): 355.77 U/ml, Fish Meal(1%): 303.83 U/ml. Results showed that fermentations carried out with carob pod extract has higher manananase enzyme activity values than glucose substrate. Also, obtained data indicated that this kind of nitrogen and carbon sources can be an economical alternative to expensive sources when they are used with together.