Model-based Optimization of Biopolymer Production from Glycerol

Kavita Sharmaa,Ashok Kumar Srivastava,T. R. Sreekrishnan

doi:10.15255/cabeq.2020.1864

Kavita Sharmaa, Ashok Kumar Srivastava

Open Access

https://doi.org/10.15255/cabeq.2020.1864

Copy DOI

Abstract

The present study focuses on sustainable production of biodegradable polymers by <br /> Cupriavidus necator DSMZ 545 using glycerol as substrate. The batch growth and biopolymer production kinetics were established in a 7-L bioreactor, which resulted in a <br /> total biomass of 8.88 g L–1 and poly(3-hydroxybutyrate) (PHB) accumulation of 6.76 g L–1. The batch kinetic and independently acquired substrate inhibition data were then used to develop a mathematical model for PHB production process. This was eventually used to design different nutrient feeding strategies under constant feed rate, decreasing feed rate, and pseudo steady state of substrate (glycerol) to optimize the PHB production during fed-batch cultivation. Among all the fed-batch cultivation strategies, the highest PHB accumulation and productivity of 13.12 g L–1 and 0.27 g L–1 h–1, respectively, was <br /> achieved in fed-batch bioreactor cultivation where a pseudo steady state with respect to <br /> glycerol was maintained.

Highlights

IntroductionPHAs (polyhydroxyalkanoates) have received considerable attention as a substitute for synthetic polymers
PHAs have received considerable attention as a substitute for synthetic polymers
One way to reduce the overall cost of PHB production process is to use cheaper substrates, which can be coupled with highly efficient isolation and purification protocols for PHB to economize the production cost further

Summary

Introduction

PHAs (polyhydroxyalkanoates) have received considerable attention as a substitute for synthetic polymers Do they possess properties similar to conventional petrochemistry-derived plastics, but are biodegradable in nature. The major abeyance in the large-scale production of biopolymers is the cost of PHA production of PHB, which is currently much higher than conventional plastic, thereby making them less popular than their counterpart[1]. This is primarily due to high substrate cost, low concentration of PHB in the growing cells, low rate of PHB accumulation, and expensive recovery protocols of the PHB. With the increasing global interest in biofuel production, it was considered interesting to examine the availability of this industrial by-product (glycerol)

Objectives

Methods

Results

Discussion

Conclusion