Streptomyces fungus

The fungus Streptomyces erythreus is the source of a number of structurally related macrolide antibiotics that are collectively known as the erythromycins. The erythromycins occupy a prominent position in medicine by virtue of their useful antibacterial properties. Their use in therapy over the course of the last three decades has been widespread, and has resulted in the saving of many human lives. In this chapter, we address the landmark total synthesis of erythronolide B (1), the biosynthetic precursor of all the erythromycins, by E.J. Corey and his coworkers which was carried out at Harvard in the 1970s.1... 

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. 

Tillotson RD, A surface active protein involved in aerial hyphae formation in the filamentous fungus Schizophyllum commune restores the capacity of a bald mutant of the filamentous bacterium Streptomyces coelicolor to erect aerial structures. Mol... 

Tacrolimus (previously known as FK506) is a macrolide antibiotic which is obtained from the fungus Streptomyces tsukubaensis. Tacrolimus binds in-tracellularly to the protein FKBP (FK binding protein) which is distinct from the protein that binds cyclosporine. However both drug-protein complexes associate in a similar way with calcineurin and inhibits its serine/threonine phosphatase activity, although the immunosuppressive potency of tacrolimus is approximately 100 fold higher than that of cyclosporine. 

Streptozocin (Zanosar), a water-soluble nitrosourea produced by the fungus Streptomyces achromogenes, acts through methylation of nucleic acids and proteins. In addition, it produces rapid and severe depletion of the pyridine nucleotides nicotinamide adenine dinucleotide (NAD) and its reduced form (NADH) in liver and pancreatic islets. 

Sialidases have a wider distribution in Nature than have the sialic acids. They have been found in a variety of viruses (mainly ortho- and para-myxoviruses) which do not usually contain sialic acids,in many pathogenic and nonpathogcnic bacteria,110-3 10 -30H in several strains of the fungus Streptomyces alhus,309 in such protozoa as Trichomonas foetus,310,311 and in animal, including human, tissues.110,312... 

Lactone structures have recently been determined for two microbial metabolites which have antibiotic properties. Antibiotic 1233A (77) was the first /8-lactone to be isolated from a fungus. Esterastin (78), an inhibitor of esterase, is produced by a strain of Streptomyces (71JCS(C)3888, 78MI51300). 

Actinomycin D is a complex chemical compound produced by the Streptomyces species of fungus and is used as an antibiotic. It is a well-established and potent teratogen and is also suspected of being carcinogenic. 

Asparaginases with antilymphoma activity have also been found in extracts of Serratia marcescens (35-37), Erwinia carotovora (38), and Proteus vulgaris (36). Escherichia coli extracts contain a second asparaginase that is devoid of antilymphoma activity (39), and a similarly inactive enzyme has been found in a fungus, Fusarium tricinctum (40). An enzyme from Streptomyces griseus has L-asparaginase activity when assayed in tris-Cl (pH 8.6) but little or no activity in sodium borate (pH... 

Electron probe microanalysis also shows that Ca2+ is a prominent constituent of the y-particle in the zoospore of the fungus Blastocladiella emersonii201 Ca2+ also induced zoospores of the fungus Phytophthora cinnamomi to encyst, and subsequently to germinate, while other cations induced encystment only.202 There is a high Ca2+ content in Streptomyces spores, and release of Ca2+ is an early event in spore germination.203... 

Tacrolimus is a 23-membered lactone chain isolated in 1984 from Streptomyces tsukubaensis, although it was originally found in a soil fungus. It is a macrolide antibiotic, and its name is derived from Tsukuba macrolide immunosuppressant. ... 

A Streptomyces strain isolated from Brazilian (Maytenus aquifolia) and South African (Putterlickia retrospinosa, Putterlickia verrucosa) plants has furnished celastramycin A (1212) (1225). A new isomer of the known rumbrin ( ) was isolated from an Australian soil ascomycete, Gymnoascus reessii, and named (12 ,)-isorumbrin (1213) (1226). Somewhat earlier, the three related auxarconju-gatins A, B, and (3 Z)-A (1214-1216) were characterized from an Arizona soil microorganism Auxarthron conjugatum (1227). A basidiomycete fungus from a New Zealand forest, Chamonixia pachydermis, produces pachydermin (1217) (1228). 

A new halogen-containing member of the penitrem family of indole-diterpe-noids, which have insecticidal activity (1397), is thomitrem A (1466) from Penicil-lium crustosum (1398). The novel dichlorinated calmodulin inhibitor, malbrancheamide (1467), was characterized from the fungus Malbranchea auran-tiaca (1399). The microbe Streptomyces rugosporus produces pyrroindomycin B (1468), which is active against both methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci (1400). The Chinese shrub Acacia confusa has yielded the unusual chlorotryptamine alkaloid 1469, which does not appear to be an artifactual dichloromethane adduct (1401). 

The immunomodulator cyclosporin was originally isolated from a soil fungus, Trichoderma polysporum (see Chapter 40). This compound was a major breakthrough for organ transplantation, because it suppressed immunological rejection of the transplanted organ. Tacrolimus (FK-506), a secondary metabolite of Streptomyces tsukabaensis, was approved in 1994 for use as an immunosuppressant in organ transplantation (De Smet, 1997). 

Kunert, J. (1989a). Biochemical Mechanism of Keratin Degradation by the actino-mycete Streptomyces fradiae and the fungus Microsporum gypseum a comparison. /. Basic Microbiol. 29, 597-604. 

Avermectins are a group of closely related compounds isolated from the fungus Streptomyces avermitilis that are used to control the parasites of humans and animals, as well as arthropod pests in crops. They have fairly high mammalian toxicity, but their movement into treated leaves, oral activity against insect pests, and rapid breakdown in sunlight are all favorable properties. In insects and worms poisoned by avermectin, inactivity and flaccid paralysis occur from its relaxing effect on muscles. 

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