Poly-γ-glutamic acid: Recent achievements, diverse applications and future perspectives

Background: Poly-gamma-glutamic acid (gamma-PGA) is a chiral biopolymer composed of either L-glutamic acid or D-glutamic acid or both monomers in different ratios and repeating frequency. It is biodegradable, water-soluble, environmentally friendly, and edible, and has versatile industrial applications. Depending on the microbial producers, the molecular weights and stereochemical compositions of gamma-PGA differ substantially, and exhibit great application diversity. It is crucial to control the structural diversity to produce tailor-made gamma-PGA.& nbsp;Scope and approach: This review presents advances in gamma-PGA synthesis in microorganisms and metabolic engineering strategies used to improve gamma-PGA diversity. The fascinating roles of structural diversity in various applications and future research directions in gamma-PGA bio-production are also discussed in this review.& nbsp;Key findings and conclusions: Obtaining the gamma-PGA with specific stereoisomer and molecular weight is an indispensable step in the expanded uses of gamma-PGA. With the development of metabolic engineering and synthetic biology, the production of tailored gamma-PGA in a single host is possible.

Automated summary

This review presents the advances in gamma-PGA synthesis and metabolic engineering strategies for improving its diversity. The importance of structural diversity in various applications is discussed, along with future research directions.