Int.J.Curr.Microbiol.App.Sci (2014) 3(8) 115-126 115 Original Research Article Production of Pleurotus tuber-regium (Fr.) Sing Agar, chemical composition and microflora associated with sclerotium U.S.Oranusi*, C.U.Ndukwe and W.Braide Department of Microbiology Federal University of Technology Owerri, Imo State, Nigeria *Corresponding author ABSTRACT Introduction Mushrooms are popularly consumed as delicacy by Nigerians as in many other countries of the world (Gregori et al., 2007; Zhang et al., 2010; Gucia et al., 2011; Nnorom et al., 2013). Pleurotus tuber- regium is an edible mushroom and like many other edible mushrooms are consumed for their nutritional value, medicinal properties and for their taste and aroma (Falendysz and Gucia, 2008; Nnorom et al., 2013). The sclerotium of Pleurotus tuber- regium is a compact mass of hardened fungal mycelium containing food reserves which help the fungi survive environmental extremes (Thorn et al., 2000). It is spherical to ovoid in shape and can be quite large measuring up to 30cm or even larger in diameter (Oso, 1997) and could weigh as ISSN: 2319-7706 Volume 3 Number 8 (2014) pp. 115-126 http://www.ijcmas.com Keywords Mushroom, Sclerotium, Chemical Composition medium, Pleurotus tuber-regium sclerotium agar Pleurotus tuber-regium is a tropical mushroom whose sclerotium is consumed like many other edible mushrooms for their nutritional value, medicinal properties and for their taste and aroma. Assessment of its chemical composition shows mean carbohydrate (63.8%), protein (12.36%), moisture (19.88%), fat (3.23%) and fiber (0.25%). Potassium, calcium, magnesium, sodium and phosphorous were present in amounts ranging from 0.028 to 0.223 %, while oxalate, tannin, flavonoid, alkaloid and hydrogen cyanide were confirmed to be present. Pleurotus tuber- regium sclerotium agar (PTRSA) was evaluated as a complex medium compared with Nutrient agar (NA) and Plate count agar (PCA) for the growth of heterotrophic organisms. Five bacteria and a fungal species (Staphylococcus aureus, Escherichia coli, Salmonella, Pseudomonas aeruginosa, Bacillus subtilis, Streptococcus and Candida albican were accessed. There was no statistical significant difference (P< 0.05) in the colony forming unit per ml (cfu/ml) recovery of these heterotrophic organisms diluted 1.8x10 8 by McFarland standard. The PTRSA function compares favorably with those of NA and PCA and can be standardized for use as a cheap medium for the cultivation of heterotrophic organisms. Evaluation of bacterial and fungal flora associated with the sclerotia shows the presence of species of Aspergillus, Bacillus, Pseudomonas, Klebsiella, and Staphylococci. Pleurotus tuber-regium is an underutilized fungus whose potentials can be further harnessed for the benefit of man.