Pulsed Feeding Strategy is More Favorable to Medium-Chain-Length Polyhydroxyalkanoates Production from Waste Rapeseed Oil

摘要

This article presents the results of production and characterization of medium-chain-length polyhydroxyalkanoates (mcl-PHAs) using Pseudomonas sp. G101. Studies have been carried out to find suitable feeding strategies for mcl-PHAs production and, for the first time, to investigate in-depth the properties of biopolyesters obtained under controlled conditions with waste rapeseed oil as a substrate. Up to 44% mcl-PHAs of cell dry weight was produced at 41 h of biofermentor culture by employing pulsed feeding of waste rapeseed oil. GC analysis showed a polymer composition with monomer length of C6 to C_(12) with Cg and C_(10) as the principal monomers. The monomeric structure of the extracted polyesters did not depend on the cultivation time and the feeding strategy. Molecular weight of the mcl-PHAs was found to be ranging from 57 to 154 kDa. Thermal analyses showed the obtained mclpolyhydroxyalkanaotes to be semi-crystalline biopolymer with promising thermal stability, having a glass transition temperature of —38 to —50°C.