Improved mannanase production from Penicillium humicola and application for hydrolysis property

Abstract

Objectives The aim of this research is to produce β-mannanases from a new microbial source using wastes in their nutrition medium. The enzyme produced can be used for the production of galactomanno-oligosaccharides, which are very useful in the health and medical fields. Materials and methods Seven fungal strains and five bacterial strains were tested for the production of β-mannanases. Enzyme activity, protein content, and biomass production were determined in all the cultures produced using standard methods. Optimization studies to maximize enzyme production from the most potent microorganisms, including culture conditions and medium compositions, were also carried out. Preliminary studies for the production of galactomanno-oligosaccharides from locust bean gum using partially purified enzymes were also carried out and followed by thin-layer chromatography techniques and Somogyi methods. Results and conclusion The highest mannanase activities were produced by Penicillium humicola (8.8 U/ml) and Penicillium spp. v (7.75 U/ml) in shaking cultures after 10 days using gum locust bean as a carbon source. Among 13 carbon sources examined, coffee residue and ceratonia seeds were the best carbon sources (10.3 and 8.9 U/ml, respectively) for P. humicola, whereas the best nitrogen source was a mixture of peptone, urea, and ammonium sulfate for the same microorganism. The optimum temperature and pH for enzyme reaction was 55 and 5.5°C, respectively. The enzyme was thermostable and retained 80% of its activity after 1 h at 50°C. The highest reducing sugar of 8900 μg/ml was obtained from locust bean gum hydrolytes after 28 h.