Bioeconomic polyhydroxyalkanoate (PHA) manufacturing, and factors boosting PHA biosynthesis

Bioeconomic polyhydroxyalkanoate (PHA) manufacturing, and factors boosting PHA biosynthesis

Abstract

Several steps of the process chain to biosynthesize microbialpolyhydroxyalkanoate (PHA) biopolyesters need to be consideredin order to make these auspicious biopolyesters quantitatively andqualitatively competitive on the global plastic market. Selection,adaptation and genetic modification of microbial strains, feedstocksupply, bioreactor design and process regime, and product recov-ery require optimization. Especially the application of robust, fastgrowing and highly productive microbial species for PHA pro-duction using inexpensive carbon-rich feedstocks has become afrequently used strategy towards economically feasible PHA pro-duction. During biosynthesis, exogenous stress factors triggeringPHA accumulation in microbial biomass play a still underestimatedrole. As recently revealed, presence of PHA helps cells to mitigatethe harmful effects of diverse stress factors like osmotic imbal-ance, oxidative challenge or UV-radiation; biotechnologically, onecan deliberately expose bacterial cells to such stress conditions toboost intracellular PHA biosynthesis. From the engineering per-spective, new bioreactors and continuous operation mode increasePHA productivity and customize PHA’s properties. Together withthe application of sustainable techniques to recover PHA frommicrobial biomass, such as using recyclable and eco-friendly sol-vents under extreme extraction conditions, PHA manufacturingcan be configured as entirely green and sustainable bioeconomictechnology.

Several steps of the process chain to biosynthesize microbialpolyhydroxyalkanoate (PHA) biopolyesters need to be consideredin order to make these auspicious biopolyesters quantitatively andqualitatively competitive on the global plastic market. Selection,adaptation and genetic modification of microbial strains, feedstocksupply, bioreactor design and process regime, and product recov-ery require optimization. Especially the application of robust, fastgrowing and highly productive microbial species for PHA pro-duction using inexpensive carbon-rich feedstocks has become afrequently used strategy towards economically feasible PHA pro-duction. During biosynthesis, exogenous stress factors triggeringPHA accumulation in microbial biomass play a still underestimatedrole. As recently revealed, presence of PHA helps cells to mitigatethe harmful effects of diverse stress factors like osmotic imbal-ance, oxidative challenge or UV-radiation; biotechnologically, onecan deliberately expose bacterial cells to such stress conditions toboost intracellular PHA biosynthesis. From the engineering per-spective, new bioreactors and continuous operation mode increasePHA productivity and customize PHA’s properties. Together withthe application of sustainable techniques to recover PHA frommicrobial biomass, such as using recyclable and eco-friendly sol-vents under extreme extraction conditions, PHA manufacturingcan be configured as entirely green and sustainable bioeconomictechnology.

polyhydroxyalkanoates; bio-economics; bacteria

polyhydroxyalkanoates; bio-economics; bacteria

KOLLER, M.; OBRUČA, S.; BRAUNEGG, G.

2020

01.11.2019

Elsevier

1873-4863

JOURNAL OF BIOTECHNOLOGY

305

Kingdom of the Netherlands

4

4

1

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http://hdl.handle.net/