Utilization of waste loquat (Eriobotrya Japonica Lindley) kernels as substrate for scleroglucan production by locally isolated Sclerotium rolfsii

Abstract

Present study mainly focused on investigating the feasibility of waste loquat kernels as substrate in submerged culture of Sclerotium rolfsii MT-6 for scleroglucan production. Loquat kernel contained high protein (22.5%) and total carbohydrate (71.2%) contents. Dried and powdered kernels were subjected to acid hydrolysis with 2 N HCl. The obtained hydrolysate was used for the preparation of loquat kernel extract (LKE) and detoxified loquat kernel extract (DLKE). S. rolfsii MT-6 was isolated from fermented squash (Cucurbita pepo). Optimal conditions for scleroglucan production were initial pH 5.0, shaking speed 150 rpm, 28°C, and cultivation time of 72 hr. Production media prepared with DLKE or LKE gave maximum biomass concentrations of 17.06 and 16.21 g/L, and maximum scleroglucan concentrations of 12.08 and 10.53 g/L, respectively. DLKE was also favorable substrate for mycelial growth in a uniform pellet form. This is a first report on the application of waste loquat kernels as scleroglucan production substrate and on the use of a local S. rolfsii isolate for this purpose.