Optimization for the efficient recovery of poly(3-hydroxybutyrate) using the green solvent 1,3-dioxolane

Abstract

In this study, a simple non-toxic recovery process of biodegradable poly(3-hydroxybutyrate) (PHB) using the green solvent 1,3-dioxolane and water was successfully developed. The critical parameters were optimized, and the process platform was scaled up from 2 ml to 1,000 ml for the efficient recovery of PHB. The physical parameters including continuous shaking, ultrasonication, extraction using the Soxhlet extractor, diluted 1,3-dioxolane, reused 1,3-dioxolane, and cell rupture by steam explosion prior to solvent extraction were carefully investigated. The results showed that continuous shaking played a major role in increasing the recovery efficiency during the scale-up process. The PHB extraction at 2 ml from dried cells at 80°C with 100 rpm of shaking speed for 5 h resulted in a recovery yield of 96.6 ± 0.1% with purity up to 99.1 ± 0.6% and that from wet cells under the same condition resulted in a recovery yield of 94.6 ± 4.8% and purity of 97.0 ± 0.1%. It should be noted that the PHB extracted from wet cells at room temperature with 150 rpm of shaking speed for 36 h resulted in a recovery yield of 93.5 ± 0.7% and purity of 97.7 ± 1.3% and had an MW of 3.1×105, MN of 2.7×105, and polydispersity index of 1.1. The direct scale-up process at 1,000 ml showed comparable results in purity, recovery yield, molecular weight distribution, thermal properties, and mechanical properties. The PHB extraction from dried cells gave the highest purity of 99.3 ± 0.5% and recovery of 94.0 ± 0.3%, whereas the PHB extraction from wet cells gave a purity of 90.3 ± 1.5% and recovery of 92.6 ± 1.0%. The novel recovery process showed its feasibility to be applied on an industrial scale.

Microwave-assisted cassava pulp hydrolysis as food waste biorefinery for biodegradable polyhydroxybutyrate production

“…KKU38 under N-limited conditions gave 5.97 g/L PHB with 61.60% PHB content which were slightly lower than those in this study ( Poomipuk et al, 2014 ) (see Table 5 for the comparison of cassava pulp hydrolysis methods). The thermal and mechanical properties including its potential applications of PHB produced by C. necator strain A-04 has already been reported ( Chanprateep and Kulpreecha, 2006 ; Wongmoon and Napathorn, 2022 ; Sinsukudomchai et al, 2023 ). Therefore, this study proposed an alternative process to convert cassava pulp waste to value-added bioproducts within biorefinery scenarios.…”

“…Cupriavidus necator strain A-04, which was previously reported to tolerate inhibitors in pineapple waste hydrolysate and to convert fermentable sugars without detoxification to PHB, was used in this study ( Chanprateep and Kulpreecha, 2006 ; Chanprateep et al, 2008 ; Sukruansuwan and Napathorn, 2018 ; Wongmoon and Napathorn, 2022 ). The bacterial strain was cultured on a nutrient agar slant at 4°C.…”

Editorial: “The value of microbial bioreactors to meet challenges in the circular bioeconomy”

“…A biodegradable plastic called poly (3-hydroxybutyrate) (PHB) was produced in a high-scale bioreactor and extracted successfully using a green solvent 1,3-dioxolane ( Wongmoon & Napathorn, 2022 ). Such a green solvent is currently used in paint manufacturing as an alternative for xylene and toluene and in the polymer business as a copolymerizing agent.…”

Application of Biopolymers as Sustainable Cladding Materials: A Review

“…PHB can be blended or combined with other polymers or fillers like wood, metal, glass, etc, to improve its properties and performance, especially to form hybrid cladding systems [56][57][58]. The formulation of PHB can be divided into two main steps: the production of PHB by microorganisms and the extraction of PHB [59].…”