Raw starch degrading amylase production by mixed culture of Aspergillus niger and Saccharomyces cerevisae grown on sorghum pomace

Abstract

Production of raw starch degrading amylase by a mixed culture of Aspergillus niger and Saccharomyces cerevisae 
grown on sorghum pomace as nutrient source was investigated. Effect of mineral nutrient supplementation of 
sorghum pomace on raw starch degrading amylase activity was also determined. Sorghum pomace medium 
significantly (P<0.05) induced higher level of raw and extracellular amylase than soluble starch medium. Mixed culture 
media recorded higher (P<0.05) level of raw starch degrading amylase than monoculture media. However, mineral 
nutrient supplementation significantly (P<0.05) suppressed raw starch degrading amylase production. The crude 
enzyme solution degraded both cereal and tuber or root starches significantly (P<0.05). Sources of crude enzyme 
significantly (P<0.05) influenced raw starch digesting activity. Optimum pH for the raw starch degrading amylase 
which varied between 3.0 and 8.0 depended on the source of the crude enzyme.