Shorten fungal treatment of lignocellulosic waste with additives to improve rumen degradability

Selective lignin degrading fungi can be used as pre-treatment to make cellulose in plant cell walls accessible for rumen microbes. According to previous studies, Ceriporiopsis subvermispora and Lentinula edodes can increase the in vitro rumen degradability of lignocellulosic biomass in 7 to 8 weeks. To shorten this treatment three additives, urea (1 µg/g or 10 µg/g), manganese (15 µg/g or 150 µg/g) and linoleic acid (0.5 mM or 1 mM), were tested during C. subvermispora or L. edodes treatment of wheat straw and wood chips. After 2 and 4 weeks samples were taken to analyse the in vitro rumen degradability and fibre content. Two weeks of fungal treatment did not increase the in vitro rumen degradability of wheat straw or wood chips and additives did not have an effect on this. Addition of manganese (both concentrations) to C. subvermispora on wood chips did result in more lignin degradation. Linoleic acid (1 mM) and manganese (15 µg/g) enhanced lignin degradation of wood chips by L. edodes after 2 weeks of treatment. Fungal treatment for four weeks increased the in vitro rumen degradability. However additives did not enhance this. Urea and manganese did result in higher lignin degradation after 4 weeks of treatment of wheat straw with C. subvermispora. The cellulose content was not changed during the fungal treatment, without or with either additive.