Effect of Carbon-Nitrogen Ratios of Lignocellulosic Substrates on the Yield of Mushroom (Pleurotus pulmonarius)

摘要

Mushrooms are fungi that are unique in the recycling of plant biomass through decomposition in the process of which they also serve as food for man. These functions are carried out through the extracellular digestion of plant biomass with a consortium of enzymes. This study examined the effect of carbon-nitrogen ratios (C/N) of three lignocellulosic substrates, namely, corncob (C/N 120:1), sawdust (C/N 325:1) and waste paper (C/N 400:1) on the yield of Pleurotus pulmonarius. The experimental design was factorial laid out in Randomized Complete Block Design (RCBD). Tissue culture was made on Potato Dextrose Agar (PDA) which was transferred to boiled sorghum grains for spawn making. The substrates were pasteurized and then inoculated with P. pulmonarius. Substrates were pasteurized (immersed in hot water for 3 hours) and inoculated with P. pulmonarius. Proximate analysis of the fruiting bodies was done to determine crude protein, crude fat, moisture content, dry matter, ash, crude fiber and carbohydrate. Carbon-nitrogen (C/N) ratio of the substrates was also determined. Corncob has C/N ratio of 120:1. The yield performance of corncob was the highest for weight (86 ± 0.01 g), length of stipe (3.55 ± 0.04 cm) and diameter of pileus (7.3 ± 0.07 cm). Means separation by least significant difference (LSD) showed that the yield parameters for corncob were statistically different from other substrates used. The proximate analysis of dried P. pulmonarius showed that corncob had a protein content of 17.37% ± 0.80% and moisture content of 0.69% ± 0.01% respectively, while sawdust and corncob had crude fibre contents of 1.79 ± 0.02 and 1.79 ± 0.01 respectively. Conclusively, having an idea of the carbon-nitrogen ratio of the substrate to be used for mushroom cultivation, manipulating the nutritional composition of mushrooms can be enhanced by enriching the growth substrates/media.