Bacteria biosynthesis

Keywords Bacteria, biosynthesis, copolyesters, Cupriavidus, Malaysian environment... 

T Kaneda. Iso- and anteiso-fatty acids in bacteria biosynthesis, function and taxonomic significance. Microbiol Rev 55 288-302, 1991. 

Extended C31 to C35 hopanes (a.k.a. Diagnostic for Bacteria biosynthesis appears to be restricted to Ourisson and Albrecht (1992),... 

Kaneda, T. (1991) Iso-fatty and anteiso-latly adds in bacteria -biosynthesis, function, and taxonomic significance. Microbiol. Rev., 55, 288-302. 

H02CC(H)(NH2)(CH2)3C(H)(NH2)C02H. M.p. at least 305"C. The o, l and meso forms are all isolated from hydrolysates of bacterial proteins. It is an intermediate in the biosynthesis of lysine in many bacteria. 

Bacteria require p-aminobenzoic acid to biosyn thesize folic acid a growth factor Structurally sul fanilamide resembles p-aminobenzoic acid and is mistaken for it by the bacteria Folic acid biosynthesis IS inhibited and bacterial growth is slowed suffi ciently to allow the body s natural defenses to effect a cure Because animals do not biosynthesize folic acid but obtain it in their food sulfanilamide halts the growth of bacteria without harm to the host... 

All these polyesters are produced by bacteria in some stressed conditions in which they are deprived of some essential component for thek normal metabohc processes. Under normal conditions of balanced growth the bacteria utilizes any substrate for energy and growth, whereas under stressed conditions bacteria utilize any suitable substrate to produce polyesters as reserve material. When the bacteria can no longer subsist on the organic substrate as a result of depletion, they consume the reserve for energy and food for survival or upon removal of the stress, the reserve is consumed and normal activities resumed. This cycle is utilized to produce the polymers which are harvested at maximum cell yield. This process has been treated in more detail in a paper (71) on the mechanism of biosynthesis of poly(hydroxyaIkanoate)s. 

Antituberculin Agents. Rifampin [13292-46-17, a semisynthetic derivative of rifamycin SV, is a most valuable dmg for treatment of tuberculosis, an infection caused by mycobacteria, leprosy, and an expanding range of other infections (23). Cycloserine [64-41-7] has been used to a limited extent for treatment of tuberculosis as a reserve dmg. Although cycloserine inhibits bacteria by interfering with their cell wall biosynthesis, it has toxic side effects in humans in the form of neurotoxicity. Capreomycin [11003-38-6] and to a much lesser extent viomycin [32988-50-4] both of which are peptides, have also been used for treatment of this disease. 

The ansa-chain of the ansamycins streptovaricins (4), rifamycins (263), geldanamycin (4), and herbimycin (32) has been shown to be polyketide in origin, being made up of propionate and acetate units with the 0-methyl groups coming from methionine. The remaining aromatic C N portion of the ansamacroHdes is derived from 3-amino-5-hydroxybenzoic acid (264—266) which is formed via shikimate precursors. Based on the precursors of the rifamycins and streptovaricins isolated from mutant bacteria strains, a detailed scheme for the biosynthesis of most of the ansamacroHdes has been proposed (95,263). 

The pathways for thiamine biosynthesis have been elucidated only partiy. Thiamine pyrophosphate is made universally from the precursors 4-amino-5-hydroxymethyl-2-methylpytimidinepyrophosphate [841-01-0] (47) and 4-methyl-5-(2-hydroxyethyl)thiazolephosphate [3269-79-2] (48), but there appear to be different pathways ia the eadier steps. In bacteria, the early steps of the pyrimidine biosynthesis are same as those of purine nucleotide biosynthesis, 5-Aminoimidazole ribotide [41535-66-4] (AIR) (49) appears to be the sole and last common iatermediate ultimately the elements are suppHed by glycine, formate, and ribose. AIR is rearranged in a complex manner to the pyrimidine by an as-yet undetermined mechanism. In yeasts, the pathway to the pyrimidine is less well understood and maybe different (74—83) (Fig. 9). 

In the biosynthesis of the thia2ole, cysteine is the common sulfur donor. In yeasts, the C-2 and N may be suppHed by glycine, and the remaining carbons byD-ribulose-5-phosphate [108321-99-9] (50). In anaerobic bacteria, the C-2 andN maybe recmited from tyrosine and the carbons from D-l-deoxyxylulose [16709-34-5] (51), whereas in aerobic bacteria the C-2 and N maybe derived from glycine, as in yeasts 7 (74—76,83—86) (see Fig. 9). 

Animals caimot synthesize the naphthoquinone ring of vitamin K, but necessary quantities are obtained by ingestion and from manufacture by intestinal flora. In plants and bacteria, the desired naphthoquinone ring is synthesized from 2-oxoglutaric acid (12) and shikimic acid (13) (71,72). Chorismic acid (14) reacts with a putative succinic semialdehyde TPP anion to form o-succinyl benzoic acid (73,74). In a second step, ortho-succmY benzoic acid is converted to the key intermediate, l,4-dihydroxy-2-naphthoic acid. Prenylation with phytyl pyrophosphate is followed by decarboxylation and methylation to complete the biosynthesis (75). 

Bacitracin. Bacitracin, a cycHc peptide active against gram-positive bacteria, was discovered in 1943. Bacitracin received dmg certification in 1949 (60—62). Whereas human usage of bacitracin is almost exclusively topical, the vast majority of bacitracin manufactured worldwide is used as an animal feed additive. Reviews of work on bacitracin include its chemistry (63—67), comprehensive aspects (62), medical aspects (62,68), biosynthesis on large enzyme complexes and genetics (69—71), and production (71,72). 

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