Solid state fermentation of Lathyrus sativus and sugarcane bagasse by Pleurotus sajor-caju

Abstract

Lathyrus sativus (Khesari plant) and sugarcane bagasse are considered as agro wastes. Khesari plants are generally grown in fields as weeds and they have to be removed prior to cultivation. Taking this view in mind, we have investigated the conversion of these lignocellulosic agro-waste as an enriched feed stock for cattle via by solid state fermentation using a cellulolytic fungus, Pleurotus sajor-caju. The strain required 8 weeks to complete the fermentation on both the untreated and treated (with alkali, lime and presoaked) substrates at 30°C. Higher amounts of reducing sugar and soluble protein were found in each of the lime treated substrates than untreated substrates. Results also indicated that presoaked substrate contain higher amounts of reducing sugar and soluble protein than unsoaked substrate. Among the substrates, mixed substrate (khesari plant + sugarcane bagasse) was found to accumulate higher amount of sugar, 22.15 mg/g and protein, 22.80 mg/g than those of khesari plant in the 5 th week of fermentation. The treatments that augmented the level of sugar and protein were also found to enhance the cellobiase, carboxy methyl cellulase and avicelase activity of crude culture extracts. These results suggest that lime treatment and presoaking seem to increase the digestibility of the substrates by the fungal cellulolytic enzymes. During eight weeks of fermentation, relatively higher cellobiase activity was found as compared to that of carboxymethylcellulase and avicelase at 30oC for the fungul strain. The results of the present study clearly indicate that fungal conversion with pretreatment transform these lignocellulosic agro-wastes to a nutritionally enriched animal feed.