<abstract xmlns="http://www.w3.org/1999/xhtml">Polyhydroxyalkanoates, microbial polyesters produced <italic>in vivo</italic> starting from renewable resources, are considered the future materials of choice to compete recalcitrant petro-chemical plastic on the polymer market. In order to make polyhydroxyalkanoates market-fit, (techno)economics of their production need to be improved. Among the multifarious factors affecting costs of polyhydroxyalkanoate production, increased volumetric productivity is of utmost importance. Improving microbial growth kinetics and increasing cell density are strategies leading to a high concentration of catalytically active biomass within a short time; after changing cultivation conditions, these cells can accumulate polyhydroxyalkanoates as intracellular products. The resulting increase of volumetric productivity for polyhydroxyalkanoates can be realized by supplying complex nitrogen sources to growing microbial cultures. In the present study, the impact of different expensive and inexpensive complex nitrogen sources, in particular whey retentate, on the growth and specific growth rates of <italic>Hydrogenophaga pseudoflava</italic> was tested.Based on a detailed kinetic process analysis, the study demonstrates that especially whole (not hydrolyzed) whey retentate, an amply available surplus material from dairy industry, displays positive effects on cultivations of <italic>H. pseudoflava</italic> in defined media (increase of concentration of catalytically active biomass after 26.25 h of cultivation by about 50%, increase of specific growth rate μ from 0.28 to 0.41 1/h during exponential growth), while inhibiting effects (inhibition constant <italic>K i</italic> = 6.1 g/L) of acidically hydrolyzed whey retentate need to be overcome. Considering the huge amounts of surplus whey accruing especially in Europe, the combined utilization of whey permeate (carbon source) and whey retentate (complex nitrogen source) for biopolyester production can be considered a viable bioeconomic strategy for the next future.</abstract>

Polyhydroxyalkanoates, microbial polyesters produced in vivo starting from renewable resources, are considered the future materials of choice to compete recalcitrant petro-chemical plastic on the polymer market. In order to make polyhydroxyalkanoates market-fit, (techno)economics of their production need to be improved. Among the multifarious factors affecting costs of polyhydroxyalkanoate production, increased volumetric productivity is of utmost importance. Improving microbial growth kinetics and increasing cell density are strategies leading to a high concentration of catalytically active biomass within a short time; after changing cultivation conditions, these cells can accumulate polyhydroxyalkanoates as intracellular products. The resulting increase of volumetric productivity for polyhydroxyalkanoates can be realized by supplying complex nitrogen sources to growing microbial cultures. In the present study, the impact of different expensive and inexpensive complex nitrogen sources, in particular whey retentate, on the growth and specific growth rates of Hydrogenophaga pseudoflava was tested.Based on a detailed kinetic process analysis, the study demonstrates that especially whole (not hydrolyzed) whey retentate, an amply available surplus material from dairy industry, displays positive effects on cultivations of H. pseudoflava in defined media (increase of concentration of catalytically active biomass after 26.25 h of cultivation by about 50%, increase of specific growth rate μ from 0.28 to 0.41 1/h during exponential growth), while inhibiting effects (inhibition constant K i = 6.1 g/L) of acidically hydrolyzed whey retentate need to be overcome. Considering the huge amounts of surplus whey accruing especially in Europe, the combined utilization of whey permeate (carbon source) and whey retentate (complex nitrogen source) for biopolyester production can be considered a viable bioeconomic strategy for the next future.

Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer <italic>Hydrogenophaga pseudoflava</italic> strain DSM1023

Institute of Biotechnology and Biochemical Engineering

The EuroBiotech Journal

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer  strain DSM1023

Polyhydroxyalkanoates, microbial polyesters produced in vivo starting from renewable resources, are considered the future materials of choice to compete...

Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer Hydrogenophaga pseudoflava strain DSM1023

Article Category: Research Article

Published Online: Apr 24, 2019

Page range: 78 - 89

DOI: https://doi.org/10.2478/ebtj-2019-0009

Keywords
Bioeconomy, biopolyesters, biopolymers, complex nitrogen sources, feedstocks, growth additives, industrial waste, polyhydroxyalkanoates (PHA), whey, whey retentate

© 2019 Martin Koller, Paula Hesse, Gerhart Braunegg, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Application of whey retentate as complex nitrogen source for growth of the polyhydroxyalkanoate producer Hydrogenophaga pseudoflava strain DSM1023

Article Category: Research Article

Published Online: Apr 24, 2019

Page range: 78 - 89

DOI: https://doi.org/10.2478/ebtj-2019-0009

KeywordsBioeconomy, biopolyesters, biopolymers, complex nitrogen sources, feedstocks, growth additives, industrial waste, polyhydroxyalkanoates (PHA), whey, whey retentate

© 2019 Martin Koller, Paula Hesse, Gerhart Braunegg, published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Keywords
Bioeconomy, biopolyesters, biopolymers, complex nitrogen sources, feedstocks, growth additives, industrial waste, polyhydroxyalkanoates (PHA), whey, whey retentate