Effect of aeration on the growth and sporulation of Aspergillus niger in cassava stalks bioconversion

Abstract

Aspergillus niger is a mould which can be used in bioconversion of cassava stalks through solid-state fermentation. Mould is aerobic microorganism and require oxygen for their growth. Sufficient supply of oxygen by aeration will give better growth of mold, but excess of oxygen will act as a bad condition and encourage production of spores. Moulds at sporulation stage will not produced enzymes required for bioconversion of lignocellulosic material, for example cassava stalks. The aim of this study was to know effect of aeration on the growth and sporulation of Aspergillus niger in bioconversion of cassava stalks. Aspergillus niger FNCC 6114 were grown on media of cassava stalks powder moistened with water in 1:1 ratio, incubated inside of two kinds of incubators. The first, incubator of plastic box at 20 L capacities without aeration. The second, incubator equipped with aquarium aerator for force-aeration and IV needles for controlling the speed of aeration at 40 mL/min. Based on the result, it was shown that fermented media from aerated incubator were: higher glucosamine content, lower reducing sugar content, and higher spores quantity. These indicated that aeration at the speed of 40 mL/min will encourage growth and increase sporulation of Aspergillus niger FNCC 6114.