Lactic acid and methane: improved exploitation of biowaste potential

G Dreschke; M Probst; A Walter; T Pümpel; J Walde; H Insam

doi:10.1016/j.biortech.2014.10.136

Lactic acid and methane: improved exploitation of biowaste potential

Bioresour Technol. 2015 Jan:176:47-55. doi: 10.1016/j.biortech.2014.10.136. Epub 2014 Nov 4.

Authors

G Dreschke¹, M Probst², A Walter³, T Pümpel⁴, J Walde⁵, H Insam⁶

Affiliations

¹ Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria. Electronic address: gillidreschke@gmx.at.
² Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria. Electronic address: Maraike.Probst@uibk.ac.at.
³ Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria. Electronic address: a.walter@uibk.ac.at.
⁴ Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria. Electronic address: Thomas.Puempel@uibk.ac.at.
⁵ Department of Statistics, University of Innsbruck, Universitätsstraße 15, 6020 Innsbruck, Austria. Electronic address: Janette.Walde@uibk.ac.at.
⁶ Institute of Microbiology, University of Innsbruck, Technikerstraße 25d, 6020 Innsbruck, Austria. Electronic address: Heribert.Insam@uibk.ac.at.

PMID: 25460983
DOI: 10.1016/j.biortech.2014.10.136

Abstract

This feasibility study investigated a two-step biorefining approach to increase the value gained by recycling of organic municipal solid waste. Firstly, lactic acid was produced via batch fermentation at 37°C using the indigenous microbiome. Experiments revealed an optimal fermentation period of 24h resulting in high yields of lactic acid (up to 37gkg(-1)). The lactic acid proportion of total volatile fatty acid content reached up to 83%. Lactobacilli were selectively enriched to up to 75% of the bacterial community. Additionally conversion of organic matter to lactic acid was increased from 22% to 30% through counteracting end product inhibition by continuous lactic acid extraction. Secondly, fermentation residues were used as co-substrate in biomethane production yielding up to 618±41Nmlbiomethaneg(-1) volatile solids. Digestate, the only end product of this process can be used as organic fertilizer.

Keywords: Biogas potential; Fermentation; Lactobacillus; Municipal organic solid waste; Waste treatment.

Publication types

Evaluation Study
Research Support, Non-U.S. Gov't

MeSH terms

Base Sequence
Biofuels*
Biotechnology / methods*
Cluster Analysis
DNA Primers / genetics
Denaturing Gradient Gel Electrophoresis
Fermentation
High-Throughput Nucleotide Sequencing
Lactic Acid / biosynthesis*
Lactic Acid / isolation & purification
Lactobacillus / genetics
Lactobacillus / growth & development
Lactobacillus / metabolism*
Methane / biosynthesis*
Molecular Sequence Data
Phylogeny
Refuse Disposal / methods*
Time Factors

Substances

Biofuels
DNA Primers
Lactic Acid
Methane