In organic chemistry, polyketides are a class of natural products derived from a precursor molecule consisting of a chain of alternating ketone and methylene groups: [−C(=O)−CH2−]n. First studied in the early 20th century, discovery, biosynthesis, and application of polyketides has evolved. It is a large and diverse group of secondary metabolites caused by its complex biosynthesis which resembles that of fatty acid synthesis. Because of this diversity, polyketides can have various medicinal, agricultural, and industrial applications. Many polyketides are medicinal or exhibit acute toxicity. Biotechnology has enabled discovery of more naturally-occurring polyketides and evolution of new polyketides with novel or improved bioactivity.
Natamycin, also known as pimaricin, is an antifungal medication used to treat fungal infections around the eye. This includes infections of the eyelids, conjunctiva, and cornea. It is used as eyedrops. Natamycin is also used in the food industry as a preservative.
Polyene antimycotics, sometimes referred to as polyene antibiotics, are a class of antimicrobial polyene compounds that target fungi. These polyene antimycotics are typically obtained from some species of Streptomyces bacteria. Previously, polyenes were thought to bind to ergosterol in the fungal cell membrane and thus weakening it and causing leakage of K+ and Na+ ions, which could contribute to fungal cell death. However, more detailed studies of polyene molecular properties have challenged this model suggesting that polyenes instead bind and extract ergosterol directly from the cellular membrane thus disrupting the many cellular functions ergosterols perform. Amphotericin B, nystatin, and natamycin are examples of polyene antimycotics. They are a subgroup of macrolides.
Streptomyces spectabilis is a bacterium species from the genus of Streptomyces. Streptomyces spectabilis produces hangtaimycin, gentamicin, kanamycin, neomycin B, sisomycin, tobramycin, paromomycin, spectinabilin, spectinomycin, aminocyclitol, actinospectacin, prodigiosine and the streptovaricin complex.
Streptomyces calvus is a bacterium species from the genus of Streptomyces which has been isolated from soil in Dinepur in India. Streptomyces calvus produces nucleocidin, adiposin 1 and adiposin 2.
Streptomyces cellulosae is a bacterium species from the genus of Streptomyces which has been isolated from garden soil. Streptomyces cellulosae produces fungichromin.
Streptomyces chartreusis is a bacterium species from the genus of Streptomyces which has been isolated from soil in Africa. Streptomyces chartreusis produces N-deacyltunicamycin, elsamicin A, aminoacylase and chartreusin.
Streptomyces durmitorensis is a bacterium species from the genus of Streptomyces which has been isolated from soil from the Durmitor National Park in Serbia and Montenegro.
Streptomyces actuosus is a bacterium species from the genus of Streptomyces. Streptomyces actuosus produces nosiheptide and staurosporin.
Streptomyces griseoaurantiacus is a thermotolerant bacterium species from the genus of Streptomyces which was isolated from marine sediment. Streptomyces griseoaurantiacus produces the antibiotics manumycin, diperamycin and chinikomycin, and griseolic acid.
Streptomyces griseocarneus is a bacterium species from the genus of Streptomyces which has been isolated from soil. Streptomyces griseocarneus produces hydroxystreptomycin, alboverticillin, sphingomyelinase C and rotaventin.
Streptomyces griseoluteus is a bacterium species from the genus of Streptomyces which has been isolated from soil in Tokyo in Japan. Streptomyces griseoluteus produces griseoluteic acid, griseolutein A and griseolutein B.
Streptomyces kasugaensis is a bacterium species from the genus of Streptomyces which has been isolated from soil from the city Nara in Japan. Streptomyces kasugaensis produces kasugamycin and thiolutin.
Streptomyces lavenduligriseus is a bacterium species from the genus of Streptomyces. Streptomyces lavenduligriseus produces Pentenomycin II, Pentenomycin III and narangomyci.
Streptomyces lydicus is a bacterium species from the genus of Streptomyces which has been isolated from soil in the United States. Streptomyces lydicus produces actithiazic acid, natamycin, lydimycin, streptolydigin, and 1-deoxygalactonojirimycin. Streptomyces lydicus can be used as an agent against fungal plant pathogens like Fusarium, Pythium, Phytophthora, Rhizoctonia and Verticillum.
Streptomyces netropsis is a bacterium species from the genus of Streptomyces. Streptomyces netropsis produces the antibiotics netropsin and distamycin A and the antifungal polyene mycoheptin.
Streptomyces nitrosporeus is a bacterium species from the genus of Streptomyces which has been isolated from garden soil in Japan. Streptomyces nitrosporeus produces Benzastatin E, Benzastatin F, Benzastatin G Nitrosporeusine A and Nitrosporeusine B and the antibiotics nitrosporin and virantomycin and the inhibitor of angiotensin-converting enzyme foroxymithine. Streptomyces nitrosporeus can degrade cellulose.
Streptomyces pactum is a bacterium species from the genus of Streptomyces. Streptomyces pactum produces pactamycin, actinopyrones, and piericidins.
Streptomyces violaceoruber is a bacterium species from the genus of Streptomyces. Streptomyces violaceoruber produces protoactinorhodin, kendomycin, phospholipase A2, granaticin and methylenomycin A.
Streptomyces violaceusniger is a bacterium species from the genus of Streptomyces. Streptomyces violaceusniger has antifungal activity. Streptomyces violaceusniger produces isoafricanol and spirofungin.
