Pectinolytic and cellulolytic activities of heat resistant fungi and their macerating effects on mango and African mango

Abstract

Five heat resistant fungi (HRF), Neosartorya fischeri, N fischeri var spinosa, N quadricincta, Paecilomyces varioti and Byssochlamys nivea, were studied for production of pectinolytic and cellulolytic activities. All isolates produced considerable hydrolase, lyase and pectinesterase activities. Hydrolase activities were significantly higher in fruit tissue (mango and African mango) media than in pectin medium (P < 0.01) when assayed by both cup plate and viscometric methods. Activities produced in both fruit media were comparable in N fischeri, N fischeri var spinosa and P varioti but not in N quadricincta and B nivea. All isolates produced greater lyase activities in pectin medium than in fruit tissue media except for N quadricincta, while the converse was the case for pectinesterase. P varioti did not utilise carboxymethyl cellulose or produce cellulase activity. Other isolates produced cellulase with B nivea producing the greatest activity. Each isolate caused considerable maceration of artificially inoculated mango and African mango fruits, which is not directly related to measurable pectinase or cellulase. The possibility of co-operation between pectinase and cellulase activities in the disintegration of fruit tissues is discussed. © 1999 Society of Chemical Industry