Increasing the efficiency of sugar beet pulp saccharification by Trichoderma reesei superior mutants for bioethanol production

Sugar beet pulp is one of the sugar industries by-products which can be used for cellulase enzyme production, Enzymatic Saccharification, and alcohol production due to its high percentage of lingo-cellulosic content. Trichoderma spp. is an important fungus that produces a wide range of cellulytic enzymes. In this study, cellulase enzyme was produced by placing sugar beet pulp in Trichoderma fermentation media together with 21 gamma irradiated T. reesei mutants and then shaking at 180 rpm at 28 °C for 72 h. All isolates were screened for cellulytic enzyme production. T. r M5 mutanthad the highest level of endo-glucanase, total cellulase, and exo-glucanase enzymeactivity among the all mutants and primary parental isolates. It also had optimum ß-glucosidase activity. The protein profile of T. r M5 mutant was analyzed using SDS-PAGE test. T. r M5 had different enzymatic bands with variable molecular weight related to EG IV, Cel 3C, Cel 3D, Cel 3A, Cel 7A, Cel 6A, Cel 5A, and Cel 61A enzymes. Results showed that T. r M5 mutant had the highest efficiency for sugar beet pulp saccharification among the all mutants. Sugar beet pulp saccharification was carried out within 1 h using enzymes produced by this mutant. The amount of alcohol production from sugar released by industrial yeast stains Saccharomyces cerevisiae and Kluyveromyces marxianus was evaluated. Alcohol production in T. r M 5 was 1.5-2 times more than its parent, T. reesei.