Poly‐γ‐glutamic Acid

Abstract

Introduction Historical Outline Chemical Analysis Chemical Synthesis Molecular Structure Molecular Spring Chemical Modification Esterification Crosslinking Producers Glutamic Acid‐dependent Producers Glutamic Acid‐independent Producers Physiology Nullification of Immunity in Infectious B. anthracis Neutralization of Near‐cell Surface in Alkalophiles Prevention of Drastic Dehydration under High‐saline Conditions in Halophiles Regulation of Osmotic Pressure in Cnidarians Molecular Genetics Encapsulation ( cap ) Genes Poly‐γ‐glutamic Acid Synthesis ( pgs ) Genes Regulatory Genes Biosynthesis Poly‐γ‐glutamic Acid Precursor Biosynthesis Poly‐γ‐glutamic Acid Biosynthesis Biodegradation Occurrence Enzymology Molecular Genetics Applications Potential Applications Biodegradable Plastics and Hydrogels Bioremediation Other Applications Manufacturers Outlook and Perspectives Patents

Genetically Engineered Poly-γ-glutamate Producer fromBacillus subtilisISW1214

“…It appears likely that the pgsB, -C, and -A genes are at least indispensable for transformation of E. coli into a PGA producer, 1,16,18) but a recent study of PGA production by B. subtilis cells suggests that both the ywsC (corresponding to pgsB) and ywtA (pgsC) gene products are indeed essential, but that the ywtB (pgsA) gene product is dispensable. 18) We expected that a genetic complementation test of MA41 about PGA productivity would give a clue to this puzzle.…”

“…4) B. subtilis ISW1214 is thus similar to naturally occurring PGA over-producers of B. subtilis, such as B. subtilis (natto) and B. subtilis subsp. chungkookjang, 1) in the requirement of a high concentration of L-glutamate for PGA production.…”

“…In contrast, the extracellular polymer from Bacillus subtilis is actually a mixture of multi-anionic copolymers in which D-and L-glutamyl residues are randomly aligned, 1) as in the case of poly--DL-glutamate (DL-PGA). Although two distinct mechanisms for the biosynthesis of DL-PGA have been proposed, 1) it was difficult to assess whether, in the polymer production by B. subtilis cells, it is formed from L-glutamate alone, 4,5) as does B. licheniformis, or whether D-glutamate also serves as a substrate 6) according to an amide ligase 7,8) -like manner. 9,10) Intricate regulation of PGA production in B. subtilis 11,12) causes a difficulty in the interpretation of this issue.…”

“…C and centrifuged at 12;000 Â g for 30 min at 4 C. PGA was prepared from the supernatant according to the usual procedures 1) and purified by anion-exchange chromatography. 15) Purified PGA was determined by the method described previously.…”

Expression of thepgsBEncoding the Poly-gamma-DL-glutamate Synthetase ofBacillus subtilis (natto)

“…[14][15][16][17][18][19] The pgsBCAywtC operon of B. subtilis (natto) directs PGA synthesis, 1,20,21) and the gene products PgsB, C, A, and YwtC are thought to form a PGA synthetase complex in the cytoplasmic membrane. 1,3) PgsB is an ADP-forming ATPase belonging to the MruD family, and is considered to have a catalytic center for polymerization. 1,20,21) PgsA and YwtC genetically interact, 1,22) but the precise functions of PgsA, PgsC, and YwtC are still obscure, even though they are essential for PGA synthesis.…”