Chapter 25 - Biosynthesis of polyglutamic acid (γ-PGA), a biodegradable and economical polyamide biopolymer for industrial applications

There are several research papers published in scientific journals on the subject of polyglutamic acid (γ-PGA or PGA). PGA has been described for its varied biochemical properties, sanctioning it to play different roles, depending on the microorganism used for its biosynthesis, and also the environmental and cultural conditions applied in the process of its production. PGA has numerous potential applications like a thickener, cryoprotectant, humectant, drug carrier, biological adhesive, flocculants or heavy metal absorbent, etc. Due to its property of biodegradability, it could have potential applications in the cosmetics, medicine, and food and water treatments. This chapter overviews and describes the knowledge available on its production. A search of bibliographic references for peer-reviewed research literature was undertaken focusing on all aspects of biosynthesis of PGA, and specific types of microorganisms employed. In all, 37 most relevant publications have been selected for the review of information
of this topic. Information gathered on all aspects of PGA biosynthesis and its application has been structured in suitable sections of review. The information included in this review confirms the importance of selecting a most suitable bacterial species of Bacillus in fermentation to produce a specific type of PGA. Whereas, certain modifications could be incorporated in the fermentation system using selected microorganism as biocatalyst, to improve the overall productivity and the quality of PGA for its appropriate applications in food or pharmaceutical industry.