This study was conducted to evaluate the effect of useSaccharomyces cerevisiae ortow Candida isolates (Candida utilis and C. tropicalis ) extract at 0.0 , 12.5 , 25 and 50 g.l.-1 and the extract ofSaccharomyces cerevisiae andtow Candida isolates at 12.5 g.l.-1fromeachgenus onmycellium growthof oyster mushroom ( Pleurotus ostreatus), mat and protein content.
The results revealed that the best mycelial growth rate ofP. ostreatus ( 8.98 cm after 7 days ) was obtained with use media prepared from extract of 50 g.l.-1 of tow candida isolates and on media prepared from extract of 12.5 g.l.-1from S. cerevisiaeand 12.5 g.l.-1from C. utilis and C. tropicaliscompared to control treatment which given 4.50 cm . Where the best mat weight ( 0.0912 g.50ml-1of broth media ) was obtained after 24 days with the use of media prepared from extract of 12.5 g.l.-1 of S. cerevisiaeand 12.5 g.l.-1from C. utilis and C. tropicalis , whileusing media prepared from extract of 12.5 g.l.-1 of S. cerevisiae compared with the control which given 0.0037 g.50 ml-1 broth mediaafter 24 days from the inoculation.On the other hand the use of media prepare with extract of 12.5 g.l.-1from C.utilis andC. tropicalis given best result of protein content 21.11% compared with controlwhichgiven17.91%