Acidogenic valorization of food industry wastes for polyhydroxyalkanoate (PHA) biosynthesis

International Conference and Exhibition on Biopolymers & Bioplastics

August 10-12, 2015 San Francisco, USA

Mariana Matos, Carlos Silva, Pedro Cardoso, Rafaela Cruz, Gilda Carvalho, Adrian Oehmen, Maria Reis

Scientific Tracks Abstracts: J Material Sci Eng

Abstract :

A high variety of wastes/wastewater/surplus products from food industry are a promising source of organic matter (e.g.
sugars) that can be valorized through biotechnological processes. Anaerobic acidogenesis converts these feed stocks into
fermentation products (FP) with multiple applications, among which the production of polyhydroxyalcanoates (PHA) by
mixed microbial cultures. The aim of this study was to examine acidogenic fermentation of twelve industrial wastes (including
wastes or by-products of fruit, wine, beer and oil industries) for their potential as substrates for PHA production to be used
in food packaging. It is known that the profiles of FP highly affect the properties of subsequently produced PHA, namely the
proportion of HB (acetate, butyrate and ethanol): HV (propionate, valerate, and lactate) precursors. The physico-chemical
characteristics of the feed stocks (organic matter, sugars, nutrients and solids) were analyzed, and batch tests were carried
out to assess their acidogenesis potential. Based on these results and on estimated availability, seasonability and cost of each
waste, the most promising feedstock (fruit processing waste) was further investigated. The latter studies were carried out
in a continuous stirred tank reactor inoculated with sludge from a full scale anaerobic digester, to determine the operating
conditions that maximize productivity and enable the manipulation of the FP profile. The FP stream was fed to a reactor
containing a PHA accumulating mixed culture. The polymer produced was offline and online analyzed in terms of monomeric
composition and physical/thermal properties determined. This study demonstrated that fruit pulp waste is a valuable feedstock
for acidogenic fermentation, and that controlling the acidogenic reactor operational conditions (pH, OLR, HRT) it is possible
to manipulate the acidogenic fermentation products in order to produce an appropriate proportion of HB/HV precursors for
food packing applications.
Aknowledments:
• EuroPHA is supported by the European Commission under the Grant Agreement FP7-604770.
• SFRH/BD/104767/2014, Fundo Social Europeu and Fundos Nacionais do MEC.

Biography :

Maria A Reis has a PhD in Biochemical Engineering, and is Group Leader of the Biochemical Engineering Group at the Universidade Nova de Lisboa, Portugal.
Her research area is Environmental/Industrial Bioengineering, with special focus on the development of sustainable bioprocesses for the removal of pollutants
from water and wastewater streams, and for the exploitation of industrial wastes for the production of biopolymers. She is co-author of 4 National patents and 5
International patents. She has published over 200 papers in scientific journals, and she is presently Editor of Water Research.