Abstract

Chemical compositions of Zea mays cobs biodegraded by Lentinus subnudus and Pleurotus tuber-regium

Author(s): S.G.Jonathan, A.Akinfemi

Agro-industrialwastes constitute great nuisance to our environment. These wastes could be recycled into other useful products such as animal feeds and organic fertilizers. Two white rot fungi (Lentinus subnudus and Pleurotus tuber- regim) were collected from the Botanical Nursery section, University of Ibadan, Nigeria and tissue cultured to generate hyphal starter cultures. Inoculation of active mycelia of these microoranisms into agricultural wastes(maize cobs, Zea mays) in a solid state fermentation for 56 days resulted in significant increase (P>0.05) in the crude protein (CP), ether extract (EE) and ash contents (AC) of the fermented wastes. Crude protein (CP)of themaize cob increased significantly from6.71 g/100gDM control (UM) after 8 weeks to 10.64 and 9.50 g/100g DMfor LSMand PT respectively. Likewise, the EE value ofUMwas 0.37 g/100gDMwhile that of PT and LSMincreased to 1.38 and 0.65 g/100gDMrespectively. The dry matter (DM) and crude fibre fractions (CRF) of the treated wastes also reduced significantly in comparismwith that of the control (P>0.05). However, acid detergent fractions (ADF) reduced from47.03 g/100g DM(control) to 41.98 and 40.76 g/100gDMrespectively inLSMand PT. In vitro gas production ranged from0.16ml h-1 (UM) to 0.20ml h-1 for LSMand 0.11ml h-1 for PT. The volume of final gas (a+b) produced also differ in values considerably. For LSM, it was 15.00ml h-1, and 19.67ml h-1 for PT but the control (UM) had the value of 11.67ml h-1.Which was significantly lower than the treated cobs(P>0.05). Significant incresed valueswere also obtained in the fungal treated maize cobs as compared with the control for short chain fatty acid (SCFA), organic matter digestibility (OM) and metabolisable energy (ME). Treatment of maize cobs with the two fungi were also observed to enhance invitrol digestibility in ruminants.