Streptomyces fungi

During the biosynthesis of the cell wall, the muropeptide is formed from acetylmuramyl-pentapeptide, which terminates in a D-alanyl-D-alanine. The synthesis of this precursor is inhibited by the antibiotic cycloserine (9.36), a compound produced by many Streptomyces fungi but which is not used clinically. During the crosslinking of the pen-tapeptide precursor, the terminal fifth alanine must be split off by a transpeptidase enzyme. This last reaction in cell wall synthesis is inhibited by the p-lactam antibiotics. 

Pentalenolactone is the name given to an antibiotic extracted from Streptomyces fungi with an Interesting tricyclic structure. 

Fig. 53.2 Whole cell biotransformation of flavonoids by wild-type cells of Streptomyces, fungi, and plant cells...

Cephamycins (3 a) a novel class of cephalosporins, produced by certain Streptomyces fungi and actinomycetes, have been shown - to possess a... 

Fermentation. The commercial P-lactam antibiotics which act as starting material for all of the cephalosporins ate produced by submerged fermentation. The organisms used for the commercial production of the penicillins and cephalosporins ate mutants of PenicU/in chTysogenum and Cephalosporium acremonium respectively (3,153,154). Both ate tme fungi (eucaryotes). In contrast, the cephamycins ate produced by certain species of procaryotic Streptomyces including Streptomyces clavuligerus and Streptomyces lipmanii (21,103). 

Leucomycines Ai and A3 Magnamydns A and B Middamydn Corresponding 4"-0- deisovaleryl derivatives Cunninghamella elegans and other fungi Streptomyces sp. 

Amphotericin B Streptomyces nodosus Fungi Cell membrane... 

Natamycin is a fungicide used to keep cheese from getting moldy. It works by making holes in the cell membranes of fungi, so their insides leak out. It is produced by Streptomyces natalensis bacteria. 

However, important as the /3-lactams are, they are but one of mai r families of anhbiotics (Chapter 5). Furthermore, most industrial microorganisms used to make j8-lactams are fungi this is atypical of anhbiotics as a whole where bacteria, particularly Streptomyces spp., predominate. Chapter 5 and some of the further reading at the end of this chapter provide the broad perspechve, including informahon on those anribiohcs made by total or partial chemical synthesis, against which this present account with its necessarily selechve subject matter should be read. 

Siderophores are iron-complexing compounds of low molecular weight that are synthesized by bacteria and fungi, and serve to deliver iron to the microbes. Because of their exclusive affinity and specificity for Fe3+, natural siderophores and synthetic derivatives have been exploited in the treatment of human iron-overload diseases. The most successfully used example is Desferal , which is the methane sulfonate derivative of iron-free ferrioxamine B, a linear trihydroxamate (Figure 3.2). Ferrioxamine was isolated in 1958 from the culture supernatant of Streptomyces... 

The poly(HA) depolymerases of the bacteria Alcaligenes faecalis (strains AE122 and Tl), Comamonas acidovorans, Comamonas testosteroni, Comamonas sp., Pseudomonas fluorescens, Pseudomonas lemoignei, Pseudomonas stutzeri, Ralstonia pickettii, Streptomyces exfoliatus, and of the fungi Paecilomyces lilaci-nus, Penicillium funiculosum, and Penicillium pinophilum have been purified and characterized (for details see Table 1). Poly(HA) depolymerases share several characteristics ... 

The degradation of azo dyes in aerobiosis can also be carried out by lignindegrading fungi, mainly white-rot fungi, or by peroxidase-producing bacterial strain, mainly Streptomyces species, as extensively reviewed by Stolz [4]. 

Streptomyces griseus NRRL 8090 catalyzes a series of biotransformations of naphthalene and 2-methyl-1,4-naphthaquinone to their corresponding racemic and diastereomeric 4-hydroxy-1-tetralones (Figure 12.1). The yields of 4-hydroxy-l-tetralone obtained with S. griseus are much higher than those produced by various fungi that oxidize naphthalene. ... 

Chacko et al. (1966) reported DDT dechlorinated to DDD by six actinomycetes Norcardiasp., Streptomyces albus, Streptomyces antibioticus, Streptomyces auerofaciens, Streptomyces cinna-moneus, Streptomyces viridochromogenes) but not by eight fungi. The maximum degradation observed was 25% in 6 d. 

Blasticidins are produced by Streptomyces grieseochro -mogens and inhibit several species of bacteria and fungi (31). Pseudomonas is particularly vulnerable to blasticidin S. Piricularia oryzae causing the blast disease of rice is widely controlled with blasticidin S in Japan. It is applied to the rice plants after infection by the fungus has already ocurred(32), since the antibiotic affects the myce -lial phase more than the spore phase. It would be desirable to search for spore killing antibiotics to control soil-inhabiting microbes and to destroy the inoculum before it infects the crop. 

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