School of Sciences, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton WV1 1 LY, UK.
School of Engineering, Computing and Mathematical Sciences, Faculty of Science and Engineering, University of Wolverhampton, Wolverhampton WV1 1LY, UK.
Biotechnol Adv. 2022 Dec;61:108049. doi: 10.1016/j.biotechadv.2022.108049. Epub 2022 Oct 13.
Bio-derived materials have long been harnessed for their potential as backbones of biodegradable constructs. With increasing understanding of organismal biochemistry and molecular genetics, scientists are now able to obtain biomaterials with properties comparable to those achieved by the petroleum industry. Poly-γ-glutamic acid (γ-PGA) is an anionic pseudopolypeptide produced and secreted by several microorganisms, especially Bacillus species. γ-PGA is polymerised via the pgs intermembrane enzymatic complex expressed by many bacteria (including GRAS member - Bacillus subtilis). γ-PGA can exist as a homopolymer of L- glutamic acid or D- glutamic acid units or it can be a co-polymer comprised of D and L enantiomers. This non-toxic polymer is highly viscous, soluble, biodegradable and biocompatible. γ-PGA is also an example of versatile chiral-polymer, a characteristic that draws great attention from the industry. Increased understanding in the correlation between microbial genetics, substrate compositions, fermentation conditions and polymeric chemical characteristics have led to bioprocess optimisation to provide cost competitive, non-petroleum-based, biodegradable solutions. This review presents detailed insights into microbial synthesis of γ-PGA and summaries current understanding of the correlation between genetic makeup of γ-PGA-producing bacteria, range of culture cultivation conditions, and physicochemical properties of this incredibly versatile biopolymer. Additionally, we hope that review provides an updated overview of findings relevant to sustainable and cost-effective biosynthesis of γ-PGA, with application in medicine, pharmacy, cosmetics, food, agriculture and for bioremediation.
生物衍生材料长期以来一直被用于其作为可生物降解结构骨架的潜力。随着对生物体内生化和分子遗传学的理解不断加深，科学家们现在能够获得具有与石油工业相当性能的生物材料。聚-γ-谷氨酸（γ-PGA）是一种由几种微生物（尤其是芽孢杆菌属）产生和分泌的阴离子假多肽。γ-PGA 通过许多细菌（包括 GRAS 成员 - 枯草芽孢杆菌）表达的 pgs 内膜酶复合物聚合。γ-PGA 可以是 L-谷氨酸或 D-谷氨酸单元的均聚物，也可以是由 D 和 L 对映体组成的共聚物。这种无毒聚合物具有高粘性、可溶性、可生物降解性和生物相容性。γ-PGA 也是多功能手性聚合物的一个例子，这一特性引起了业界的极大关注。对微生物遗传学、基质组成、发酵条件和聚合化学特性之间相关性的理解的提高，导致了生物工艺的优化，以提供具有成本竞争力的、非石油基的、可生物降解的解决方案。本综述详细介绍了微生物合成 γ-PGA 的情况，并总结了目前对产生 γ-PGA 的细菌的遗传构成、培养条件范围以及这种多功能生物聚合物的物理化学性质之间相关性的理解。此外，我们希望本综述提供了对与可持续和具有成本效益的 γ-PGA 生物合成相关的发现的最新概述，该综述在医学、药学、化妆品、食品、农业和生物修复方面具有应用。
