Direct bioethanol production from breadfruit starch (Artocarpus communis forst) by engineered simultaneous saccharification and fermentation (ESSF) using microbes consortium

Abstract

Breadfruit (Artocarpus communis Forst.) is one of sources for bioethanol production, which has high starch content (89%). Bioethanol production from breadfruit starch was conducted by Simultaneous Saccharification and Fermentation (SSF) technology using microbes consortium. The aim of the research was to examine a method to produce bioethanol by SSF technology using microbes consortium at high yield and efficiency. The main research consisted of two treatments, namely Conventional SSF and Enginereed SSF (ESSF). The results showed that ConventionalSSF using aeration and agitation during cultivation could produce ethanol at 11.15 ± 0.18 g/L, with the yield of product (Yp/s) 0.34 g bioethanol/g substrate; and yield of biomass (Yx/s) 0.29 g cell/g substrate, respectively. A better result was obtained using Engineered SSF (ESSF) in which aeration was stopped after biomass condition has reached the end of the exponential phase. The bioethanol produced was 12.75 ± 0.04 g/L, with an conversion efficiency of 75% to products, yields of product (Yp/s) 0.41 g bioethanol/g substrate, and the yield of cell (Yx/s) 0.09 g cell/g substrate.