New Biological Functions and Applications of High‐Molecular‐Mass Poly‐γ‐glutamic Acid

Abstract

Ultra-high-molecular-weight poly-gamma-glutamic acid (gamma-PGA) is a most promising biodegradable polymer that is produced by Bacillus subtilis (chungkookjang). Attractive properties of gamma-PGA are that it is water soluble, anionic, biodegradable, and edible. Development of gamma-PGA has pursued in terms of cosmetics/skin care, bone care, nanoparticle for drug delivery system, hydrogel, and so on. Very recently, our research has shown that gamma-PGA can be used as an immune-stimulating agent, especially at high molecular weight. This review presents the synthesis and production of high-molecular-weight gamma-PGA and its various applications in industrial fields.

Poly-γ-Glutamic Acids Contribute to Biofilm Formation and Plant Root Colonization in Selected Environmental Isolates of Bacillus subtilis

“…Bacillus subtilis is also known to produce other secreted polymeric substances, including poly-γ-glutamic acids (γ-PGA), a polymer with the size ranging from ∼10 to ∼1000 kDa (Ashiuchi et al, 1999; Ashiuchi and Misono, 2002; Morikawa et al, 2006; Poo et al, 2010; Ogunleye et al, 2015). Because this polymer is biodegradable, γ-PGA may have important applications in the medical field and industry (Ashiuchi and Misono, 2002; Poo et al, 2010; Ogunleye et al, 2015).…”

Effects of high molecular weight poly-γ-glutamic acid on PIGS with porcine preproductive and respiratory syndrome virus (PRRSV) infection

“…chungkookjang [1,4,23] in PRRSV infection. Pigs treated with HM-γ-PGA after PRRSV infection demonstrated more resistance when challenged with a highly virulent PRRSV strain, MN184, and exhibited higher weight gain and enhanced levels of protective immune responses.…”

“…Bacillus subtilis chungkookjang, a strain used for the production of a transitional Korean fermented seasoning soybean food, has been reported to uniquely produce a higher molecular weight γ-PGA (HM-γ-PGA, >2,000 kDa) than that of Bacillus subtilis natto (10-1,000 kDa) [1][2][3][4]. γ-PGA is an anionic polymer and a naturally occurring homo-polyamide that is made of D-and L-glutamic acid units connected by amide bonds between α-amino and γ-carboxylic acid groups.…”

“…Recent studies have shown that the high molecular mass γ-PGA from Bacillus subtilis possesses functional and immune activation effects. Thus, in the past few years, potential applications of γ-PGA and its derivatives have been of interest as biomaterials in a wide range of industrial fi elds, such as food, cosmetics/skin care, bone care, medicine and water treatment [4][5][6]. Previous studies have demonstrated that HM-γ-PGA exhibited signifi cant antitumor activity in mice bearing major histocompatibility (MHC) class 1-defi cient tumors.…”

Biocompatible Nanopolymers: The Next Generation of Breast Cancer Treatment?

“…A poly(g,l-glutamic acid)–cisplatin conjugate effectively inhibited human breast tumor xenografts in nude mice [9]. High molecular weight poly-g-glutamic acid purified from natural sources has been found to be immunostimulating [10]. …”