Development of a Novel Spawn (Block Spawn) of an Edible Mushroom, Pleurotus ostreatus, in Liquid Culture and its Cultivation Evaluation.

Mushroom cultivation has gained increased attention in recent years. Currently, only four types of spawn, including sawdust spawn, grain spawn, liquid spawn, and stick spawn, are commonly available for mushroom cultivation. This limited spawn diversity has led to difficulty in selecting suitable inoculum materials in some cultivation. In this study, three small blocks of lignocellulosic agro-wastes and one block of a synthetic matrix were prepared as support for growing Pleurotus ostreatus in liquid medium. Mycelium-adsorbed blocks were then evaluated for their potential as block spawn for fructification. Our results indicated that the edible fungus was adsorbed and abundantly grew internally and externally on loofah sponge and synthetic polyurethane foam (PUF) supports and also has the ability to attach and grow on the surface of sugarcane bagasse and corncob supports. The mycelia of P. ostreatus adhered on corncob exhibited the highest metabolic activity, while those on the PUF showed the least activity. Mycelial extension rates of block spawns made of agro-waste materials were comparable to that of sawdust spawn, but the block spawn of PUF showed a significantly lower rate. No significant differences in cropping time and yield were observed among cultivations between experimental block spawns and sawdust spawns. Moreover, the corncob block spawn maintained its fruiting potential during an examined period of 6-month storage. The developed block spawn could be practically applied in mushroom cultivation.

Investigating the Effect of Tissue Size on Mycelial Growth of Seven Mushroom Species by Using a Novel Device for Precise Tissue Isolation.

Tissue isolation from mushrooms is frequently practiced by both researchers and growers to isolate new and improved strains. In the present study, we designed a simple and convenient device for precise tissue isolation and therefore investigated the effect of tissue size on mycelial growth of seven mushroom species. The developed device consists of a cutting needle and a transfer needle. The cutting needle was used to obtain circular tissue plugs having a height up to 3 mm and variable diameters (2-5 mm) from mushroom fruit bodies. The transfer needle was a stainless steel round rod (1.5 mm in diameter) with a blade-like end. It can be used for collecting mushroom tissue when the cutting needle fails to extract it. With the aid of these devices, precise tissue isolation was achieved. Plate cultures demonstrated that tissue size had little effect on mycelium extension for Lentinula edodes (the winter shiitake), Hypsizygus marmoreus, and Agrocybe aegerita, but influenced the aerobic mycelium density. For Pleurotus ostreatus, Pleurotus eryngii, and Volvariella volvacea, large tissue plugs produced faster mycelial growth and higher aerobic mycelium density compared with small ones. On the contrary, small plugs from the tissue of the flower shiitake and Agaricus bisporus favored mycelial growth. The present study revealed that the preferable tissue size for mycelial growth varies among mushroom species, and the developed device is expected to greatly facilitate the isolation of new and improved mushroom strains.