Growth kinetics and morphology study of Grey Oyster mushroom (Pleurotus pulmonarius) from spore induction liquid spawn colonization on sawdust substrate

Abstract

In mushroom industry, grey oyster mushroom (Pleurotus pulmonarius) is commonly cultivated by using solid spawn. In the present study, liquid spawn is proposed as an alternative to replace solid spawn because solid spawn takes longer time for mycelium run in the bag and the final yield is low. Liquid spawn was prepared by culturing spawn in Potato Dextrose Broth while solid spawn was prepared by culturing spawn in grains. This study aims to investigate the growth kinetics and morphology of P. pulmonarius on sawdust substrate by liquid spawn and comparison was made with solid spawn which act as control. Screening of parameters variables was performed using OFAT to determine the effect of the parameters on the mycelial growth rate and morphology. The parameters studied were storage condition, storage period and inoculum volume. The storage condition was set at cold 4°C and ambient 25°C±2°C, while the storage period used was 1, 2 and 3 months. As for the inoculum volume used was 3ml, 5ml and 7ml. From these parameters, they were arranged into 18 combinations. From the findings, it was discovered that the liquid spawn stored at 4°C for 1 month with 7ml inoculum volume demonsrated the highest mycelial growth rate (0.3946 cm/day) and highest average weight of fruiting bodies (123.0 g). Also, the average diameter of caps (12.6 cm) yield from this spawn is the highest. Besides, liquid spawn took only 48 days for complete spawn run while solid spawn took 57 days for complete spawn run. Hence, liquid spawn has the potential to be commercialized for the advantages it has over solid spawn, for instance, shorter spawn run period and higher yield.