BIOMASS AND EXOPOLYSACCHARIDE PRODUCTION BY MORCHELLA ESCULENTA IN SUBMERGED CULTURE USING THE EXTRACT FROM WASTE LOQUAT (ERIOBOTRYA JAPONICA L.) KERNELS

Abstract

ABSTRACT Detoxified loquat kernel extract (DLKE) and neutralized loquat kernel extract (LKE) prepared from waste loquat kernels were used as main carbon sources in the submerged and solid cultures of Morchella esculenta. LKE and DLKE were found to be good substrates as they resulted in mycelial biomass and exopolysaccharide (EPS) concentrations near to those obtained with malt extract (ME). In the production media prepared with ME, DLKE and LKE, the maximum biomass concentrations were 18.9, 16.7 and 14.6 g/L, and the maximum EPS concentrations were 5.3, 5.2 and 4.1 g/L, respectively. EPS produced by mushrooms has various biologic and pharmacologic activities, including antitumor, immunostimulating and hypoglycemic activities. On the other hand, mushroom mycelia produced by submerged fermentation have the potential to be used in the human diet. To the best of our knowledge, this is the first report on the usability of this waste material as a substrate in microbial culture media. PRACTICAL APPLICATIONS The hydrolyzate prepared from loquat kernel flour was used for the preparation of detoxified and neutralized extracts. Both extracts could be effectively used as a substrate in the submerged and solid cultures of Morchella esculenta; however, their usage in submerged culture will be more advantageous as submerged culture provides faster and more efficient production of mycelial biomass and exopolysaccharide (EPS) in mushrooms. The present study is very important for industrial, environmental and food microbiology as it proved that an agricultural origin-waste material could be effectively utilized as a substrate for the production of mycelial biomass and EPS in submerged culture of an edible mushroom.