Promoting chain elongation in mixed culture acidification reactors by addition of ethanol

In this research we investigate a microbial production process to produce medium chain fatty acids (MCFAs) based on the organic fraction of municipal solid waste (OFMSW). In this microbial production process, called chain elongation, bacteria produce medium chain fatty acids (MCFAs) from ethanol and volatile fatty acids (VFAs). MCFAs could be used as new biomass based building blocks for the chemical and fuel industry. The objective of this article is to investigate whether chain elongation can be promoted during acidification of OFMSW by addition of ethanol. The results show that chain elongation can be promoted during acidification of OFMSW by addition of ethanol. However, the hydrolysis rate and the carboxylic acid yield of the OFMSW in reactors with ethanol additions were lower than the hydrolysis rate and the carboxylic acid yield than in reactors without ethanol additions. Further research is required to determine whether a combined chain elongation and acidification reactor or a separated reactor system is more advantageous for MCFA production from OFMSW.

[1]  W. Kenealy,et al.  Studies on the substrate range of Clostridium kluyveri; the use of propanol and succinate , 1985, Archives of Microbiology.

[2]  Yu-bao Gao,et al.  Biological Control of Phytopathogenic Fungi by Fatty Acids , 2008, Mycopathologia.

[3]  Huang Hao,et al.  Process optimization for PHA production by activated sludge using response surface methodology , 2009 .

[4]  Heijo Scharff,et al.  Effect of pH and VFA on hydrolysis of organic solid waste , 2000 .

[5]  Michael Renz,et al.  Ketonization of Carboxylic Acids by Decarboxylation: Mechanism and Scope , 2005 .

[6]  L. T. Angenent,et al.  Chain elongation with reactor microbiomes: upgrading dilute ethanol to medium-chain carboxylates , 2012 .

[7]  L. T. Angenent,et al.  Waste to bioproduct conversion with undefined mixed cultures: the carboxylate platform. , 2011, Trends in biotechnology.

[8]  E. ten Brummeler,et al.  Dry anaerobic digestion of the organic fraction of municipal solid waste , 1993 .

[9]  Witholt,et al.  Perspectives of medium chain length poly(hydroxyalkanoates), a versatile set of bacterial bioplastics , 1999, Current opinion in biotechnology.

[10]  H. Hamelers,et al.  Alcohol production through volatile fatty acids reduction with hydrogen as electron donor by mixed cultures. , 2008, Water research.

[11]  B. Pietrangeli,et al.  The Acidogenic Digestion of the Organic Fraction of Municipal Solid Waste for the Production of Liquid Fuels , 1993 .

[12]  A H Veeken,et al.  Effect of substrate-seed mixing and leachate recirculation on solid state digestion of biowaste. , 2000, Water science and technology : a journal of the International Association on Water Pollution Research.

[13]  Hubertus V. M. Hamelers,et al.  Biological formation of caproate and caprylate from acetate: fuel and chemical production from low grade biomass , 2011 .

[14]  Daniel P. Smith,et al.  Reduced product formation following perturbation of ethanol‐ and propionate‐fed methanogenic CSTRs , 1989, Biotechnology and bioengineering.

[15]  Fuli Li,et al.  The genome of Clostridium kluyveri, a strict anaerobe with unique metabolic features , 2008, Proceedings of the National Academy of Sciences.

[16]  P. F. Levy,et al.  Biorefining of biomass to liquid fuels and organic chemicals , 1981 .

[17]  Hongzhang Chen,et al.  Effect of ethanol and yeast on cellulase activity and hydrolysis of crystalline cellulose , 2006 .

[18]  M. V. van Loosdrecht,et al.  Influence of ammonium on the accumulation of polyhydroxybutyrate (PHB) in aerobic open mixed cultures. , 2010, Journal of biotechnology.

[19]  P. Weimer,et al.  Production of caproic acid by cocultures of ruminal cellulolytic bacteria and Clostridium kluyveri grown on cellulose and ethanol , 1995, Applied Microbiology and Biotechnology.