INVESTIGATION OF GROWTH CONDITIONS ON THE LACCASE ACTIVITY OF PLEUROTUS OSTREATUS AND CERIPORIOPSIS RIVULOSUS DURING LOW QUALITY FORAGE UPGRADE AS POSSIBLE DRY SEASON FEED

Résumé

This paper investigated the effects of some growth conditions i.e. forage-liquid ratio and fermentation time on the laccase activity of Pleurotus ostreatus (PO) and Ceriporiopsis rivulosus (CR) when used to upgrade selected low quality forages as possible dry season feed for ruminants. PO and CR were cultivated on Brachiaria decumbens (BD), Andropogon gayanus (AG), Triticum aestivum (TA) and Lolium perenne (LP) alongside untreated forages using two forage-liquid ratios (1:3 and 1:5) for each selected solid state fermentation times (14 and 28 days). The laccase activity of CR increased when the forages were in liquid ratio of 1: 5 at higher fermentation time with the exception of BD in ratio 1:3 at 28th day. The laccase activity of PO was increased when the forages were in liquid ratio of 1:3 at higher fermentation with the exception of TA in liquid ratio of 1:5. Generally increased fermentation time did not have much effect on the laccase production of each of the fungi on LP and TA; had minimal effect on AG; and had much effect on BD. It can therefore be concluded that for a higher laccase production to be recorded, CR should be cultivated on LP and TA in ratio 1:5 for shorter time, AG in ratio 1:5 for longer time, and BD in ratio 1:3 for a longer period. PO should be cultivated on AG and BD in ratio 1:3 for longer time, LP in ratio 1:3 for shorter time, and TA in ratio 1:5 for shorter time.