Scale‐up processing with different microparticle agent for β‐mannanase production in a large‐scale stirred tank bioreactor

Abstract

Beta (β)-mannanase is one of the most important enzymes used in the industry and they are produced in particularly with Aspergillus sojae. In this study, large-scaled mannanase production by recombinant A. sojae (ATCC 11906) was performed at 30ºC, 15 lpm aeration rate, and 204 rpm stirring speed in the bioreactor (30-L). Fed-batch and microparticle enhanced cultivation strategies were used to improve the scale-up production in both glucose and carob pod extract media. For this purpose, different concentrations of magnesium silicate (3MgO.4SiO2.H2O, talc) (1, 3, 5, and 10 g/L) and aluminum oxide (Al2O3) (1, 5, 10, and 15 g/L) as microparticle agents were supplemented into the fermentation media. The maximum enzyme activity was determined from carob extract-based medium as 302.6 U/ml with the addition of 3 g/L of magnesium silicate. Microparticle-enhanced large-scale bioreactor was successfully used to control the fungal growth, to perform repeatable fermentations, and to scale-up β-mannanase productions in fermentation. Practical applications The role of mannanases in the energy, detergent, paper, pulp, and feed industry is well established and recently they have found the application field in the food technologies such as fruit maceration, gum modification, production of instant coffee and prebiotics, etc. Mannanases are mostly extracellular enzymes hydrolyzing the 1,4-β-D-mannosidic linkages in mannans, galactomannans, glucomannans, and galactoglucomannans. Mannanases are enzymes produced mainly from microorganisms but mannanases produced from plants have also been reported. However, microbes are the most potent producers of mannanases and represent the preferred source of enzymes because of their rapid growth, limited spaces required for cultivation, and ready accessibility to genetic manipulation. Microbial mannanases have become biotechnological importance since they target the hydrolysis of complex polysaccharides of plant tissues into simple molecules such as mannooligosaccharides and mannoses.