School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia.
Process Systems Engineering Centre (PROSPECT), School of Chemical and Energy Engineering, Faculty of Engineering, Universiti Teknologi Malaysia, 81310, Johor Bahru, Johor, Malaysia.
J Environ Manage. 2021 Nov 15;298:113461. doi: 10.1016/j.jenvman.2021.113461. Epub 2021 Aug 19.
Polyhydroxyalkanoate (PHA) is a type of polyesters produced in the form of accumulated intracellular granules by many microorganisms. It is viewed as an environmentally friendly bioproduct due to its biodegradability and biocompatibility. The production of the PHA using oil substrates such as waste oil and plant oil, has gained considerable attention due to the high product yield and lower substrate cost. Nevertheless, the PHA fermentation using oil substrate is complicated due to the heterogenous fatty acid composition, varied bio-accessibility and possible inhibitory effect on the bacterial culture. This review presents the current state-of-the-art of PHA production from oil-based substrates. This paper firstly discusses the technical details, such as the choice of bacteria strain and fermentation conditions, characteristic of the oil substrate as well as the PHA composition and application. Finally, the paper discusses the challenges and prospects for up-scaling towards a cleaner and effective bioprocess. From the literature review, depending on the cell culture and the type of PHA produced, the oil platform can have a PHA yield of 0.2-0.8 g PHA/g oil substrate, with PHA content mostly from 40 to 90% of the cell dry weight. There is an on-going search for more effective oil-utilising PHA producers and lower cost substrate for effective PHA production. The final application of the PHA polymer influences the treatment needed during downstream processing and its economic performance. PHA with different compositions exhibits varied decomposition behaviour under different conditions, requiring further insight towards its management towards a sustainable circular economy.
聚羟基脂肪酸酯（PHA）是一种聚酯，由许多微生物以积累的细胞内颗粒的形式产生。由于其可生物降解性和生物相容性，它被视为一种环保型生物制品。使用油基底物（如废油和植物油）生产 PHA 引起了相当大的关注，因为它的产物产率高，底物成本低。然而，由于异质脂肪酸组成、不同的生物可利用性以及对细菌培养物可能的抑制作用，使用油基底物进行 PHA 发酵较为复杂。本文综述了基于油的底物生产 PHA 的最新技术。本文首先讨论了技术细节，如细菌菌株和发酵条件的选择、油底物的特性以及 PHA 的组成和应用。最后，本文讨论了朝着更清洁、更有效的生物工艺进行放大的挑战和前景。根据细胞培养和所生产的 PHA 类型，油平台可以实现 0.2-0.8 g PHA/g 油底物的 PHA 产率，PHA 含量大多占细胞干重的 40-90%。人们一直在寻找更有效的利用油的 PHA 生产者和更廉价的底物，以实现有效的 PHA 生产。最终 PHA 聚合物的应用会影响到下游处理过程中所需的处理以及其经济性能。具有不同组成的 PHA 在不同条件下表现出不同的分解行为，需要进一步深入了解其管理，以实现可持续的循环经济。
