Polyhydroxyalkanoates (PHAs) are promising alternatives that accumulate as energy and carbon storage material in various microorganisms, including bacteria and microalgae, being biodegradable and suitable for a wide variety of applications. Among these compounds, the most prevalent and well-characterized biopolymer is polyhydroxybutyrate (PHB), which belongs to the short-chain PHAs. The present study was designed to evaluate algae-based PHB production in two Chlorophyta (Desmodesmus communis and Chlorella vulgaris) under a two-phase nutritional mode of cultivation, namely a phototrophic growth phase (PGP) and a mixotrophic stress phase (MSP) with N,P-depleted media and organic carbon supply (i.e., glucose or sodium acetate, NaOAc). The highest PHB productivity (0.11 g PHB/g biomass/d; 0.015 g PHB/L/d), corresponding to 32.1 % w/w of intracellular PHB, was observed for D. communis after 3 days of cultivation under mixotrophic conditions in batch cultures (e.g., low light, phosphorus-free medium, 1 g/L of NaOAc). A scaled-up cultivation (10 L) was set up to evaluate for the first time PHB yields and biomass composition in a semi-continuous system. A PHB content of 34 % w/w was achieved on day 8, corresponding to a maximum PHB productivity of 0.10 g PHB/g biomass/d (or 0.011 g PHB/L/d), which increased up to 54 % w/w on day 15. The biomass was composed of about 30 % w/w proteins, 6 % w/w polysaccharides, and 11 % w/w lipids, which can be valorised from a biorefinery perspective. The scaled-up D. communis cultivation in 10 L PBRs confirmed the potential utilization of this algal species for PHB production with productivity up to 2-times higher than those reported for several cyanobacterial species and similar to the maximum value obtained with batch cultures in previous works performed with Scenedesmaceae.

Semi-continuous production of polyhydroxybutyrate (PHB) in the Chlorophyta Desmodesmus communis / Pezzolesi L.; Samori' C.; Zoffoli G.; Xamin G.; Simonazzi M.; Pistocchi R.. - In: ALGAL RESEARCH. - ISSN 2211-9264. - ELETTRONICO. - 74:(2023), pp. 103196.1-103196.11. [10.1016/j.algal.2023.103196]

Semi-continuous production of polyhydroxybutyrate (PHB) in the Chlorophyta Desmodesmus communis

Pezzolesi L.;Samori' C.;Zoffoli G.;Simonazzi M.;Pistocchi R.
2023

Abstract

Polyhydroxyalkanoates (PHAs) are promising alternatives that accumulate as energy and carbon storage material in various microorganisms, including bacteria and microalgae, being biodegradable and suitable for a wide variety of applications. Among these compounds, the most prevalent and well-characterized biopolymer is polyhydroxybutyrate (PHB), which belongs to the short-chain PHAs. The present study was designed to evaluate algae-based PHB production in two Chlorophyta (Desmodesmus communis and Chlorella vulgaris) under a two-phase nutritional mode of cultivation, namely a phototrophic growth phase (PGP) and a mixotrophic stress phase (MSP) with N,P-depleted media and organic carbon supply (i.e., glucose or sodium acetate, NaOAc). The highest PHB productivity (0.11 g PHB/g biomass/d; 0.015 g PHB/L/d), corresponding to 32.1 % w/w of intracellular PHB, was observed for D. communis after 3 days of cultivation under mixotrophic conditions in batch cultures (e.g., low light, phosphorus-free medium, 1 g/L of NaOAc). A scaled-up cultivation (10 L) was set up to evaluate for the first time PHB yields and biomass composition in a semi-continuous system. A PHB content of 34 % w/w was achieved on day 8, corresponding to a maximum PHB productivity of 0.10 g PHB/g biomass/d (or 0.011 g PHB/L/d), which increased up to 54 % w/w on day 15. The biomass was composed of about 30 % w/w proteins, 6 % w/w polysaccharides, and 11 % w/w lipids, which can be valorised from a biorefinery perspective. The scaled-up D. communis cultivation in 10 L PBRs confirmed the potential utilization of this algal species for PHB production with productivity up to 2-times higher than those reported for several cyanobacterial species and similar to the maximum value obtained with batch cultures in previous works performed with Scenedesmaceae.
2023
Semi-continuous production of polyhydroxybutyrate (PHB) in the Chlorophyta Desmodesmus communis / Pezzolesi L.; Samori' C.; Zoffoli G.; Xamin G.; Simonazzi M.; Pistocchi R.. - In: ALGAL RESEARCH. - ISSN 2211-9264. - ELETTRONICO. - 74:(2023), pp. 103196.1-103196.11. [10.1016/j.algal.2023.103196]
Pezzolesi L.; Samori' C.; Zoffoli G.; Xamin G.; Simonazzi M.; Pistocchi R.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/954156
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