Effect of Crude Oil on Biomass Production, Polysaccharide, and Polyphenol Content of Leucocoprinus cretaceus(Bull.) Locq. a white rot fungus

Abstract

There is need to establish the best lignocellulosic wastes with bio-stimulatory effects on mushrooms been investigated for myco-remediation purposes. Solid state fermentation of four substrates (sawdust of Anthostema aubryanum Baill, Mansonia altissima (A. Chev.) A. Chev., Nauclea diderrichii (De Eild & T. Durand) Merr and Malt Extract Agar) contaminated with various levels of crude oil contamination by Leucocoprinus cretaceus (Bull.) Locq., was studied. The effect of crude oil on mycelial biomass production, polysaccharide, and polyphenol contents of L. cretaceus during solid state fermentation of lignocellulosic wastes was determined. The polysaccharide and polyphenol content of the mycelia was determined with the Phenol-Sulphuric acid and Folin-Ciocalteu methods, respectively. Solid state fermentation of crude contaminated substrates improved biomass and polysaccharide content of L. cretaceus. The fungus is a good bioremediation agent degrading crude oil with increasing levels of crude oil contamination (28.00% in 1.00% crude oil contamination to 81% in 10.00% crude oil contamination). Radial mycelial extension increased with increasing levels of crude oil contamination. Crude oil did not cause increased polyphenol concentration and therefore not a stress factor. There was increase in polysaccharide content indicating metabolization of crude oil for metabolic build up. Supplementing crude oil contaminated substrates with the sawdust of M. altissima resulted in the highest level of crude oil degradation by the test fungus. L. cretaceus is a potential strong myco-remediation agent. This study records the first time the fungus is used for degradation of crude oil contaminated substrates. The mushroom has the potential to completely mineralize petroleum hydrocarbons.