Brevibacterium species

At the beginning of the 1980s, the wide screening of aromatic amino acid dehydrogenases led to the discovery of PheDH in Brevibacterium species [26]. The enzyme was isolated from several mesophiles—Bacillus sphaericus [27], Sporosarcina ureae [27], B. badius [28], Rhodococcus sp. [29], Nocardia sp. [30] and Microbacterium sp. [31], and also from the thermophile T. intermedius [32]—and characterize (Table 5). The enzyme acts on L-norleucine, L-methionine, L-norvaline, and L-tyrosine besides L-phenylalanine in the presence of NAD, although slowly. L-Tryptophan, L-alanine, and D-phenyManine are inert as the substrate. The enzyme shows lower substrate specificity for 2-oxo acids than that for amino acids like AlaDH and LeuDH. The values for ammonia are more than 70 mM. The T. intermedius PheDH is the most thermostable and a useful catalyst for industrial and clinical applications. The enzyme is easily and effectively purified from the recombinant E. coli [6] and commercially available (Unitika Ltd.). 

Other Microbial Systems. In addition to the systems described, gene cloning is routinely performed in several other bacterial strains including Streptoccocus Staphylococcus Brevibacterium BJdodobacter Comyebacterium Glucanobacter Acetobacter and Zanthomonas species. 

The strains used are either wild types or mutants. Wild types from the genera Arthrobacter, Bacillus, Brevibacterium, Corynebacterium and Microbacterium are mostly employed in glutamic acid and alanine production 48). The yields, depending on the carbon source and bacterial species, are between 10-80%. Other amino acids are also accumulated in wild types however, yields are lower. 

Bacteria reported to metabolize PAHs include species of Acido-vorax, Acinetobacter, Actinomyces, Aeromonas, Agrobacterium, Alcaligenes, Arthrobacter, Aureobacterium, Bacillus, Brevibacterium, Burkholderia, Chryseobacterium, Comamonas, Corynebacterium, Cycloclasticus,... 

Kawasaki, H. Usuda, Y. Shimaoka, M. Utagawa, T. Development of an improved assay for purine nucleoside kinase activity in cell extracts and detection of inosine kinase activity in Brevibacterium acetylicum ATCC 953, related species, and Corynebacterium flaccumfaciens ATCC 6887. Biosci. Bio-technol. Biochem., 64, 761-766 (2000)... 

A peptidoglycan, of different type from that of other species of Cellulo-monas, has been isolated from C. cartalyticum L-Lysine replaces ornithine and the interpeptide bridge consists of d-aspartyl-D-serine. The same peptido-glycan type has been identified in Arthrobacter luteus, Brevibacterium liticum, and Corynebacterium manihot. 

Methionine biosynthesis is controlled by the metabolic regulation of enzymes in the pathway. Species of Corynebacterium and Brevibacterium have much simpler regulatory mechanisms than E. coli for methionine biosynthesis and are the preferred microbes for overproduction. Aspartokinase is a major enzyme that catalyzes the phosphorylation of aspartic acid and redirects the flux to aspartate family of amino acids. 

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