Bioconversion of Commercial and Waste Glycerol into Value-Added Polyhydroxyalkanoates by Bacterial Strains

Abstract

The industrial conversion of renewable resources into bio-based materials has been increasingly receiving attention from an economic and, in particular, an environmental point of view. Among these bioresources, glycerol represents one of the most important base materials for the manufacturing of bulk and higher-valued products. This is mainly based on the increasing amounts of waste glycerol due to the rising production of biodiesel and other oleochemicals, as well as on the applicability of glycerol as a water-soluble carbon source for a wide range of microbial productions. Polyhydroxyalkanoates (PHAs) are biodegradable and environmentally friendly biopolymers, and the major contributor to PHA production is the substrate cost, therefore it is desirable to produce PHA from waste residues like biodiesel byproducts. Since soil ecosystems have a rich, but still insufficiently studied microbial flora, the ability of bacteria isolated from Finnish soils and sediments were investigated for the production of valueadded materials such as Polyhydroxyalkanoates based on pure and waste glycerol as carbon source. 1 out of 40 isolated strains was selected for further studies based on ability to produce PHA on mineral medium and identified as Halomonas sp SA8 with up to 56% of Polyhydroxyalkanoate accumulation. The produced biopolymer was recovered and identified as PHB homopolymer.

Production and characterization of polyhydroxybutyrate fromVibrio harveyiMCCB 284 utilizing glycerol as carbon source

“…SA8, PHB content and CDW could reach 43% (w/w) and 4·1 g l −1 , respectively, after 96 h of cultivation using glycerol (De Castro et al . ). In another study, an isolate of Zobellella denitrificans ZD1 utilized 20 g l −1 glycerol for PHB synthesis and showed a CDW of 4·8 g l −1 and PHB content of 85% (w/w) after 96‐h incubation (Ibrahim and Steinbüchel ).…”

Fermentative Production of Polyhydroxyalkanoates (PHAs) from Glycerol by Zobellella taiwanensis Azu-IN1

“…The use of 1% (v/v) glycerol was reported as the optimal concentration for PHA production in Bacillus sphaericus [19], whereas 2% (v/v) glycerol was reported to be the optimal for PHA production by Pseudomonas mendocina PSU [20], Halomonas sp. SA8 [21], and Pandoraea sp. [22].…”

Candida tropicalis BPU1 produces polyhydroxybutyrate on raw starchy substrates

“…PHB produced by Halomonas sp . SA8 showed rapid thermal degradation between 245 and 290°C whereas PHB produced by A. eutrophus showed thermal degradation between 250 and 300°C .…”