The macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Macrolides belong to the polyketide class of natural products. Some macrolides have antibiotic or antifungal activity and are used as pharmaceutical drugs. Macrolides are bacteriostatic in that they suppress or inhibit bacterial growth rather than killing bacteria completely.
Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Over 500 species of Streptomyces bacteria have been described. As with the other Actinobacteria, streptomycetes are gram-positive, and have genomes with high GC content. Found predominantly in soil and decaying vegetation, most streptomycetes produce spores, and are noted for their distinct "earthy" odor that results from production of a volatile metabolite, geosmin.
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.
Ectoine is a natural compound found in several species of bacteria. It is a compatible solute which serves as a protective substance by acting as an osmolyte and thus helps organisms survive extreme osmotic stress. Ectoine is found in high concentrations in halophilic microorganisms and confers resistance towards salt and temperature stress. Ectoine was first identified in the microorganism Ectothiorhodospira halochloris, but has since been found in a wide range of Gram-negative and Gram-positive bacteria. Other species of bacteria in which ectoine was found include:
Lincosamides are a class of antibiotics, which include lincomycin, clindamycin, and pirlimycin.
Oleandomycin is a macrolide antibiotic. It is synthesized from strains of Streptomyces antibioticus. It is weaker than erythromycin.
Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found in certain macrolide antibiotics such as the commonly prescribed erythromycin, azithromycin, clarithroymcin, methymycin, narbomycin, oleandomycin, picromycin and roxithromycin. As the name suggests, these macrolide antibiotics contain a macrolide or lactone ring and they are attached to the ring Desosamine which is crucial for bactericidal activity. The biological action of the desosamine-based macrolide antibiotics is to inhibit the bacterial ribosomal protein synthesis. These antibiotics which contain Desosamine are widely used to cure bacterial-causing infections in human respiratory system, skin, muscle tissues, and urethra.
Streptomyces scabies or Streptomyces scabiei is a streptomycete bacterium species found in soils around the world. Unlike most of the 500 or so Streptomyces species it is a plant pathogen causing corky lesions to form on tuber and root crops as well as decreasing the growth of seedlings. Along with other closely related species it causes the potato disease common scab, which is an economically important disease in many potato growing areas. It was first described in 1892, being classified as a fungus, before being renamed in 1914 and again in 1948. Several other species of Streptomyces cause similar diseases to S. scabies but other, more closely related species, do not.
Streptomyces isolates have yielded the majority of human, animal, and agricultural antibiotics, as well as a number of fundamental chemotherapy medicines. Streptomyces is the largest antibiotic-producing genus of actinobacteria, producing chemotherapy, antibacterial, antifungal, antiparasitic drugs, and immunosuppressants. Streptomyces isolates are typically initiated with the aerial hyphal formation from the mycelium.
Nourseothricin (NTC) is a member of the streptothricin-class of aminoglycoside antibiotics produced by Streptomyces species. Chemically, NTC is a mixture of the related compounds streptothricin C, D, E, and F. NTC inhibits protein synthesis by inducing miscoding. It is used as a selection marker for a wide range of organisms including bacteria, yeast, filamentous fungi, and plant cells. It is not known to have adverse side-effects on positively selected cells, a property cardinal to a selection drug.
Streptomyces antibioticus is a gram-positive bacterium discovered in 1941 by Nobel-prize-winner Selman Waksman and H. Boyd Woodruff. Its name is derived from the Greek "strepto-" meaning "twisted", alluding to this genus' chain-like spore production, and "antibioticus", referring to this species' extensive antibiotic production. Upon its first characterization, it was noted that S. antibioticus produces a distinct soil odor.
Streptomyces ambofaciens is a bacterium species from the genus Streptomyces which has been isolated from soil from France. Streptomyces ambofaciens produces ambobactin, foromacidin A, foromacidin B, foromacidin C, 18-deoxospiramicin I, 17-methylenespiramycin I and congocidin.
Streptomyces arenae is a bacterium species from the genus Streptomyces which has been isolated from soil from Illinois in the United States. Streptomyces arenae produces pentalenolactone, 2,5-dihydrophenylalanine, naphthocyclinone and arenaemycine.
Streptomyces cacaoi is a bacterium species from the genus of Streptomyces. Streptomyces cacaoi produces polyoxine.
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 halstedii is a bacterium species from the genus of Streptomyces which has been isolated from deeper soil layers. Streptomyces halstedii produces magnamycin B, vicenistatin deltamycin A2, deltamycin A3, bafilomycin B1 and bafilomycin C1. Streptomyces halstedii also produces complex antifungal antibiotics like oligomycins and the antibiotics anisomycin and sinefungin.
Streptomyces laurentii is a bacterium species from the genus of Streptomyces which has been isolated from soil. Streptomyces laurentii produces thiostrepton.
Streptomyces rishiriensis is a bacterium species from the genus of Streptomyces which has been isolated from soil in Hokkaido in Japan. Streptomyces rishiriensis produces coumermycin A1, notomycin, 2-chloroadenosine, phosphophenylalanarginine and lactonamycin.
Streptomyces thermoviolaceus is a thermophilic bacterium species from the genus of Streptomyces which has been isolated from composts. Streptomyces thermoviolaceus produces chitinase and peroxidase.
Streptomyces virginiae is a bacterium species from the genus of Streptomyces which has been isolated from soil. Streptomyces virginiae produces actithiazic acid, virginiamycins and cycloserine. Streptomyces virginiae also produces monensin A, monensin B, monensin C, monensin D, actithiazic acid.
