원문정보
초록
영어
Palm kernel cake(PKC), a by-product of palm oil industry, is a potential feed source for poultry. However, its use as poultry feed is limited due to its high fiber(mannan) content. Therefore, we have developed a bioconversion process to improve the nutritive value of PKC as poultry feed. Previously, we showed successful bioconversion of PKC by solid-state fermentation with novel
manannase producing strains. In this study, the effect of gamma-irradiation of PKC on solid-state fermentation by Bacillus subtilis MBS1 has been investigated. The irradiation itself induced release of reducing sugar and soluble protein from PKC, showing structural changes or decomposition of the substrate by gamma-ray. Neutral detergent fiber content of the irradiated PKC was decreased with an increase in the irradiation dose. The level of mannanase
produced during fermentation of irradiated PKC was much higher than that of untreated substrate. Compared with untreated PKC, the irradiated substrate showed higher decrease in hemicellulose and cellulose fractions after fermentation by Bacillus subtilis MBS1. This indicated the irradiation treatment of PKC enhanced degradation of mannan and other anti-nutritive polysaccharides
by Bacillus subtilis MBS1. These results suggest that gamma-irradiation can be effectively used to enhance bioconversion of PKC for improving its nutritive value as poultry feed.