Heterologous phasin expression in Rhodopseudomonas palustris CGA009 for bioplastic production from lignocellulosic biomass

Authors

Brandi Brown, University of Nebraska-Lincoln, Lincoln
Cheryl Immethun, University of Nebraska-Lincoln, Lincoln
Adil Alsiyabi, University of Nebraska-Lincoln, Lincoln
Dianna Long, University of Nebraska-Lincoln, Lincoln
Mark Wilkins, University of Nebraska-Lincoln, Lincoln
Rajib Saha, University of Nebraska-Lincoln, Lincoln

Date of this Version

12-26-2021

Document Type

Article

Citation

Metabolic Engineering Communications 14 (2022) e00191. https://doi.org/10.1016/j.mec.2021.e00191

Comments

© 2021 The Authors. Published by Elsevier B.V. on behalf of International Metabolic Engineering Society. This is an open access article

Abstract

Rhodopseudomonas palustris CGA009 is a metabolically robust microbe that can utilize lignin breakdown products to produce polyhydroxyalkanoates (PHAs), biopolymers with the potential to replace conventional plastics. Our recent efforts suggest PHA granule formation is a limiting factor for maximum production of the bioplastic poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by R. palustris. The Phap1 phasin (phaP1) from the PHBproducing model bacterium Cupriavidus necator H16 was expressed in R. palustris with the aim of overproducing PHBV from the lignin breakdown product p-coumarate by fostering smaller and more abundant granules. Expression of phaP1 yielded PHBV production from R. palustris aerobically (0.7 g/L), which does not occur in the wild-type strain, and led to a significantly higher PHBV titer than wild-type anaerobic production (0.41 g/L). The 3HV fractions were also significantly increased under both anaerobic and aerobic conditions, which boosts thermomechanical properties and potential for application. Thus, heterologous phasin expression in R. palustris provides flexibility for industrial processing and could foster compositional changes in copolymers with better thermomechanical properties compared to PHB alone.