Consolidated bioprocessing of the organic fraction of municipal solid waste into bioethanol
Ameya Pankaj Gupte, Noemi Di Vita, Marthinus W. Myburgh, Rosemary A. Cripwell, Marina Basaglia, Willem H. van Zyl, Marinda Viljoen‐Bloom, Sergio Casella, Lorenzo Favaro
Abstract
Organic fraction of municipal solid waste (OFMSW) has the potential to sustain large-scale biofuel production. So far, OFMSW is mainly converted into biogas by anaerobic digestion (AD), and limited research is available on its use to produce bioethanol. This paper reports, for the first time, the conversion of starch-rich OFMSW to bioethanol by using a novel yeast co-secreting both glucoamylase and alpha-amylase enzymes. As such, OFMSW can be converted to bioethanol without adding costly enzymes following a consolidated bioprocessing (CBP) approach. The OFMSW, sampled at an industrial AD plant, was processed to bioethanol with an outstanding yield, approaching 100 % of the theoretical maximum. Moreover, the co-conversion of OFSMW with starch-rice waste, namely discolored rice (DR) available in large quantities close to the AD plant, was performed to test the feasibility of valorizing different waste substrates simultaneously. The ethanol levels reached 60 g/L, indicating that both the developed process and yeast strain have important features towards ethanol production from organic waste streams.