Solid-state fermentation

About: Solid-state fermentation is a research topic. Over the lifetime, 5311 publications have been published within this topic receiving 113337 citations.

Production of Cellulase and Pectinase from Orange Peels by Fungi

Abstract: The aim of the work was to evaluate the potentials of fungi to produce pectinase and cellulase using orange peels as substrate. Fungi were isolated and identified from soil and decomposing orange peels. Fungal isolates were screened in modified Czapek-Dox media with carboxymethylcellulose and citrus pectin as the only carbon source for endoglucanase and polygalacturonase production respectively. Out of a total thirteen isolates, three highest producers of the enzymes were selected and identified as Penicillium atrovenetum, Aspergillus flavus and Aspergillus oryzae. The three isolates were further used to ferment orange peels in a solid state fermentation. The effects of incubation time, pH, temperature and nitrogen sources on the level of production of the enzymes were investigated. The three isolates produced polygalacturonase optimally on the 5th day while endoglucanase was produced optimally on the 7 th day. Highest production of polygalacturonase and endoglucanase by Penicillium atrovenetum was observed at pH 5, 40 o C and at 0.2% ammonium persulfate. Maximum production of polygalacturonase and endoglucanase by Aspergillus flavus was observed at pH 5.5, 40 o C and 0.25% ammonium persulfate while Aspergillus oryzae produced the two enzymes maximally at pH 5.5, 35 o C and 0.2% ammonium persulfate.

Screening of laccase, manganese peroxidase, and versatile peroxidase activities of the genus Pleurotus in media with some raw plant materials as carbon sources

Abstract: Species of the genus Pleurotus are among the most efficient natural species in lignin degradation belonging to the subclass of ligninolytic organisms that produce laccase (Lac), Mn-dependent peroxidase (MnP), versatile peroxidase (VP), and the H2O2-generating enzyme aryl-alcohol oxidase, but not lignin peroxidases. Production of Lac and oxidation of 2,6-dimethoxyphenol (DMP) in the presence and absence of Mn2+ were detected both in submerged fermentation (SF) of dry ground mandarine peels and in solid-state fermentation (SSF) of grapevine sawdust in all investigated Pleurotus species and strains. Evidence of cultivation methods having a distinct influence on the level of enzyme activities has been demonstrated. Most of the species and strains had higher Lac activity under SSF conditions than under SF conditions. DMP oxidation in the presence and absence of Mn2+ was detected in all investigated species and strains, but was lower under SF conditions than under SSF conditions for most of them. However, relative activities of DMP oxidation in the absence of Mn2+, as percentages of activity against DMP in the presence of Mn2+, were higher under conditions of SF than in SSF cultures in most of the investigated species and strains. The obtained results showed that strains of different origins have different efficiently ligninolytic systems and that conditions of SSF are more favorable for ligninolytic activity than those in SF owing to their similarity to natural conditions on wood substrates.

Effective Dehairing Properties of Keratinase from Paenibacillus woosongensis TKB2 Obtained Under Solid State Fermentation

Abstract: Response surface methodology was employed for optimization of the culture conditions for keratinase production by a feather-degrading Paenibacillus woosongensis TKB2 under solid-state fermentation using chicken feather as substrate. The optimized culture conditions having 2.21 g of feather, with rice straw (2:1), moistened with distilled water (1:5, w/v adjusted to pH 8.5) and fermented for 72.07 h, resulted in 2.83-fold increased keratinase production compared to non-optimized condition. The enzyme efficiently dehaired goat hides within 14 h without the use of lime. The enzyme-dehaired goat skins were evaluated by mechanical, touch-visual and electron microscopy methods and were compared with conventional chemical treated skins. The results indicated that the enzyme treated dehaired skins exhibit similar or improved characteristics without damaging the collagen layer, which makes the crude keratinase a potential candidate for application in leather industry to avoid pollution problems associated with the use of chemicals.