Conversion of solvent evaporation residues from the AB- (acetone-butanol) bioprocess into bacterial cells accumulating thermoplastic polyesters.
In a bioconversion study based on utilisation of by-products from the AB- (acetone-butanol) bioprocess a new isolated gram-negative solvent tolerant bacterium was used to convert the AB process residue after removal of the major part of the solvents. The bacterium identified as a representative of the genus Alcaligenes (designated as Alcaligenes sp. G) was capable of growth up to optical densities ranging from 8 to 20 and simultaneously of polyhydroxyalkanoate- (PHA-)accumulation up to 40% per dry weight. A standardised medium based on AB by-products containing 7 g/l of butyrate and 5 g/l of acetate at pH 7.5 was used in our studies for bioconversion into PHAs. Concentrations of 1-butanol, which is known for its membrane damaging properties in micro-organisms, were tolerated in the AB by-products medium up to 4 g/l without significant inhibition of cellular growth. No inhibition of growth was observed, when the medium was adjusted to 40 g/l butyrate. Due to the toxicity of the remaining 1-butanol maintenance of sterility is of no high priority during the process. The use of acetate and butyrate from an AB process is expected to provide a higher return-on-investment than the combustion of biogas to help meet energy demands.
Institute for Microbiology and Genetics, University of Vienna, Austria.
G
G
Parrer
G
G
Schroll
J R
JR
Gapes
W
W
Lubitz
K C
KC
Schuster
D020001:1-Butanol / Q000378:metabolism; D019342:Acetic Acid / Q000378:metabolism; D000096:Acetone / Q000378:metabolism; D000421:Alcaligenes / Q000254:growth & development / Q000378:metabolism*; D001672:Biocompatible Materials; D019149:Bioreactors; D001709:Biotechnology; D002087:Butyrates / Q000378:metabolism; D011091:Polyesters / Q000378:metabolism*; D012997:Solvents
D001672:Biocompatible Materials; D002087:Butyrates; D011091:Polyesters; D012997:Solvents; D000096:Acetone; D020001:1-Butanol; D019342:Acetic Acid