Alcaligenes faecalis, Immobilized

Remazol Black B Alcaligenes faecalis, Microbial consortium immobilized [187]... 

A number of decarboxylase enzymes have been described as catalysts for the preparation of chiral synthons, which are difficult to access chemically (see Chapter 2).264 The amino acid decarboxylases catalyze the pyridoxal phosphate (PLP)-dependent removal of C02 from their respective substrates. This reaction has found great industrial utility with one specific enzyme in particular, L-aspartate-P-decarboxylase (E.C. 4.1.1.12) from Pseudomonas dacunhae. This biocatalyst, most often used in immobilized whole cells, has been utilized by Tanabe to synthesize L-alanine on an industrial scale (multi-tons) since the mid-1960s (Scheme 19.33).242-265 Another use for this biocatalyst has been the resolution of racemic aspartic acid to produce L-alanine and D-aspartic acid (Scheme 19.34). The cloning of the L-aspartate-P-decarboxylase from Alcaligenes faecalis into E. coli offers additional potential to produce both of these amino acids.266... 

SO that in the second batch productivity was severely reduced and conversion yield was significantly lower even at prolonged operation. SDS-PAGE electrophoresis revealed that most of the desorbed protein had a molecular weight of 31,000 Da, which corresponds to that of Alcaligenes faecalis lipase. Most of the activity lost from batch to batch corresponded to protein desorption from the matrix, enzyme inactivation being quite low. Therefore, it made very little sense to use QLG instead of QL, but the free enzyme was not recoverable from the reaction medium and cost estimates indicated that the enzyme should be used at least five times to make the process economically attractive. Therefore, the next goal was to construct an immobilized lipase biocatalyst from soluble QL. The hydrophobic nature of the active site and the requirement of a hydrophobic interface for lipase action made reasonable to use hydrophobic supports however to test the validity of this hypothesis several immobilization systems were tested. The results obtained are summarized in... 

Tanio T, Fukui T, Shirakura Y, Saito T, Tomita K, Kaiho T, Masamune S (1982) An extracellular poly(3-hydroxybutyrate) depolymerase from Alcaligenes faecalis. Eur J Biochem 124 71-77 Tesema Y, Raghavan D, Stubbs J (2(X)5) Bone cell viabUity on methacrylic add grafted and collagen immobilized porous poly(3-hydroxybutyrate-co-3-hydroxyvalerate). J Appl Polym Sd 98(5) 1916-1921... 

---