LOW – COST MEDIA FORMULATIONS FOR CULTURE MAINTENANCE ANDudPROLIFIC FRUITING OF OYSTER MUSHROOMS (PLEUROTUS SPP.)

摘要

Modified media for Pleurotus sajor-caju and Pleurotus ostreatus was formulated and investigated in terms of itsudsuitability and effect on the mycelial growth rate of the Pleurotus spp. strains. The modified media was of variousudwhole-wheat grain: media (Malt extract agar[MEA] or Potato dextrose agar [PDA]) ratios of 1:1 to 1:5.udPolyethylene (PEG) 6000 was also added as its effects on growth rate at minute concentrations were noted in earlierudwork. The 1:1 ratio mixture resulted in the drying of the wheat grain by the 8th day. The water content of the mediaudformulations were all significantly different from the water content of conventional Malt Extract Agar (MEA, 3 %)ud(97.9 % water) and Potato dextrose Agar (PDA, 3 %) (97.9 % water). The water contents generally ranged fromud14.3 % (1:2 MEA) to 57.4 % (1:4 PDA). There was no clear-cut trend for the water contents of the mediaudformulations. The growth rate generally initially decreased below that obtained for normal media (MEA and PDA).udHowever the growth rate increased above that for normal media for the 1:2 to 1:5 for MEA and 1:3 to 1:5 for PDA.udThe water content of the mixtures cannot be used to predict the growth rates. Generally mushrooms are taken toudrequire adequate water however surprisingly growth higher than that for normal media was obtained for media withudlow water content. The increase in growth rate is attributed to the richness in terms of nutrients. PEG amended MEAudmedia generally resulted in higher growth rates than non-amended media. This has been the case in earlier workuddone. The crushed wheat grain : media formulations ranging from 1:2 to 1:15 with PDA and no PDA treatmentsud(the media formulation comprised only of distilled water and crushed grain) induced luxuriant mycelial growth andudprolific fruiting of the Pleurotus spp. The water content of the crushed wheat grain: media formulations ranged fromud75 % to 97 %. Water content generally increased from 1: 2 media to 1:15 media. Growth rate was highest for 1: 5 +udPDA media. 1:2 – PDA had the lowest growth rate. The low –cost media formulations 1:3 to 1:5 (whole wheatudgrain) and 1:3 to 1:15 (crushed wheat grain) have potential use as low-cost alternatives to culture Pleurotus spp. forudculture maintenance, spawn production, mushroom cultivation and bioremediation.