Production of polyhydroxyalkanoate (PHA) copolymer from food waste using mixed culture for carboxylate production and Pseudomonas putida for PHA synthesis

Rashmi Chandra; Aranksha Thakor; Tizazu H Mekonnen; Trevor C Charles; Hyung-Sool Lee

doi:10.1016/j.jenvman.2023.117650

Production of polyhydroxyalkanoate (PHA) copolymer from food waste using mixed culture for carboxylate production and Pseudomonas putida for PHA synthesis

J Environ Manage. 2023 Jun 15:336:117650. doi: 10.1016/j.jenvman.2023.117650. Epub 2023 Mar 4.

Authors

Rashmi Chandra¹, Aranksha Thakor², Tizazu H Mekonnen³, Trevor C Charles², Hyung-Sool Lee⁴

Affiliations

¹ Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
² Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
³ Department of Chemical Engineering, Institute of Polymer Research, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
⁴ Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada; KENTECH Institute for Environmental and Climate Technology, Korea Institute of Energy Technology (KENTECH) 200 Hyeoksin-ro, Naju-si, Jeollanam-do, Republic of Korea. Electronic address: hs.chris.lee@kentech.ac.kr.

PMID: 36878060
DOI: 10.1016/j.jenvman.2023.117650

Abstract

Production of polyhydroxyalkanoates (PHAs) with high concentration of carboxylate, that was accumulated from solid state fermentation (SSF) of food waste (FW), was tested using Pseudomonas putida strain KT2440. Mixed-culture SSF of FW supplied in a high concentration of carboxylate, which caused a high PHA production of 0.56 g PHA/g CDM under nutrients control. Interestingly, this high PHA fraction in CDM was almost constant at 0.55 g PHA/g CDM even under high nutrients concentration (25 mM NH₄⁺), probably due to high reducing power maintained by high carboxylate concentration. PHA characterization indicated that the dominant PHA building block produced was 3-hydroxybutyrate, followed by 3-hydroxy-2-methylvalerate and 3-hydroxyhenxanoate. Carboxylate profiles before and after PHA production suggested that acetate, butyrate, and propionate were the main precursors to PHA via several metabolic pathways. Our result support that mixed culture SSF of FW for high concentration carboxylate and P. putida for PHA production enables sustainable production of PHA in cost-effective manners.

Keywords: Carboxylate; Food waste; Leachate bed reactor; Polyhydroxyalkanoates (PHAs); Pseudomonas putida.

MeSH terms

Carboxylic Acids
Fermentation
Food
Polyhydroxyalkanoates* / metabolism
Pseudomonas putida* / metabolism
Refuse Disposal*

Substances

Polyhydroxyalkanoates
Carboxylic Acids