G\u00fcney \u00c7in Denizi'nden deniz Streptomyces sp. rssa1'in kimyasal bile\u015fenleri
\nDeniz aktinomisetleri, makrolidler, alkaloidler, peptidler, kinonlar vb. gibi \u00e7e\u015fitli yap\u0131sal tiplere sahip \u00e7e\u015fitli biyoaktif maddeler \u00fcretebilen de\u011ferli bir t\u0131bbi mikrobiyal kaynak s\u0131n\u0131f\u0131d\u0131r. Antibakteriyel bile\u015fiklerin ara\u015ft\u0131r\u0131lmas\u0131nda b\u00fcy\u00fck bir potansiyele sahiptirler. Schinke ve arkada\u015flar\u0131, 2010-2015 y\u0131llar\u0131 aras\u0131nda deniz bakterilerinden elde edilen antibakteriyel bile\u015fiklerin 69%'sinin deniz aktinomisetlerinden elde edildi\u011fini tespit etmi\u015ftir. Deniz ortam\u0131n\u0131n benzersiz do\u011fas\u0131 nedeniyle, deniz aktinomisetleri fizyolojik, biyokimyasal ve genetik arka plan \u00f6zellikleri bak\u0131m\u0131ndan karasal aktinomisetlerden farkl\u0131d\u0131r ve bu da deniz aktinomisetlerinden aktif molek\u00fcller aramay\u0131 olduk\u00e7a umut verici hale getirmektedir.<\/p>\n
Son y\u0131llarda, ara\u015ft\u0131rma ekibimiz G\u00fcney \u00c7in Denizi'ndeki deniz organizmalar\u0131n\u0131n simbiyotik ve epifitik aktinomisetlerinden yeni yap\u0131ya sahip baz\u0131 aktif molek\u00fcller bulmu\u015ftur. Son zamanlarda, \u00c7in'in Hainan eyaletindeki Xisha Adalar\u0131'ndan toplanan mercan \u00f6rneklerinden antibakteriyel aktiviteye sahip bir deniz streptomyces sp. rssa1 su\u015fu izole ettik ve tarad\u0131k, ancak antibakteriyel maddeleri net de\u011fil. Bu su\u015f taraf\u0131ndan \u00fcretilen aktif bile\u015fenleri ke\u015ffetmek amac\u0131yla, bu makalede ilk olarak kat\u0131 fermantasyon i\u00e7in pirin\u00e7 kat\u0131 k\u00fclt\u00fcr ortam\u0131 kullan\u0131lm\u0131\u015f, fermantasyon \u00fcr\u00fcnlerinin kimyasal bile\u015fimi sistematik olarak incelenmi\u015f ve aktivitesi taranm\u0131\u015ft\u0131r.<\/p>\n
Aktinobakteriler de\u011ferli t\u0131bbi mikroorganizmalar\u0131n bir s\u0131n\u0131f\u0131d\u0131r ve bug\u00fcne kadar ke\u015ffedilen do\u011fal antibiyotiklerin yakla\u015f\u0131k \u00fc\u00e7te ikisi aktinomisetlerden, \u00f6zellikle de Streptomyces'ten elde edilmi\u015ftir. Bu makalede, mercandan elde edilen Streptomyces sp. rssa1 metabolitlerinden 10 bile\u015fik izole edilmi\u015f ve tan\u0131mlanm\u0131\u015ft\u0131r. Bunlar aras\u0131nda, bile\u015fik 1 ve 2 s\u0131ras\u0131yla tetrasiklin A ve B idi ve bile\u015fik 3, kanglemisin M ad\u0131 verilen bir benzonaftokinon bile\u015fi\u011fiydi. Aktivite taramas\u0131, RAW 264.7 makrofajlar\u0131na kar\u015f\u0131 sitotoksik aktiviteye sahip oldu\u011funu g\u00f6sterdi ve \u00c7in'deki deniz aktinomisetlerinin do\u011fal \u00fcr\u00fcn k\u00fct\u00fcphanesini daha da zenginle\u015ftirdi. Bile\u015fik 4, bir diketopiperazin t\u00fcr\u00fc olan bir diketopiperazin bile\u015fi\u011fidir. Li ve arkada\u015flar\u0131, bile\u015fi\u011fin nematod \u00f6ld\u00fcrme aktivitesine sahip oldu\u011funu ve nematoda (Panagrellus redivivus) kar\u015f\u0131 48 saatlik \u00f6l\u00fcm oran\u0131n\u0131n 40% oldu\u011funu bildirmi\u015ftir. Bu makale, deniz Streptomyces'ten nematod \u00f6ld\u00fcrme aktivitesine sahip bile\u015fik 4'\u00fc ke\u015ffeden ilk makaledir ve bakterinin mahsul k\u00f6k d\u00fc\u011f\u00fcm nematod hastal\u0131klar\u0131n\u0131n \u00f6nlenmesi ve kontrol\u00fcnde de\u011ferli olabilece\u011fini g\u00f6stermektedir. Ayr\u0131ca bile\u015fi\u011fin Vibrio alginolyticus'a kar\u015f\u0131 zay\u0131f inhibit\u00f6r aktiviteye sahip oldu\u011fu ve sucul Vibrio hastal\u0131klar\u0131n\u0131n \u00f6nlenmesi ve kontrol\u00fcne y\u00f6nelik ila\u00e7lar\u0131n geli\u015ftirilmesi i\u00e7in ipu\u00e7lar\u0131 sa\u011flad\u0131\u011f\u0131 bulunmu\u015ftur. 5-10 numaral\u0131 bile\u015fikler yayg\u0131n indol veya benzen i\u00e7eren basit bile\u015fiklerdir. Bunlar aras\u0131nda, ilk olarak Jin ve arkada\u015flar\u0131 taraf\u0131ndan Salsola bitkisinden ke\u015ffedilen 7 numaral\u0131 bile\u015fik, 0,556 mg\/mL konsantrasyonda 44% inhibisyon oran\u0131 ile g\u00fc\u00e7l\u00fc \u03b1-amilaz inhibit\u00f6r aktivitesine sahiptir.<\/p>\n
Polyene macrolides are a class of highly effective and broad-spectrum antifungal antibiotics, such as natamycin, which can inhibit mold and yeast, and are used as natural food preservatives and antibacterial additives due to their good physicochemical stability. The compounds 1 and 2 isolated in this study were identified as tetracycline A and B, respectively. Both compounds have a lactone ring skeleton composed of 25 carbon atoms, with 4 conjugated double bonds and multiple hydroxyl groups on the ring. The 15th hydroxyl group is connected to an amino sugar through a glycosidic bond. The currently discovered tetracycline producing bacteria are all Streptomyces actinomycetes, first discovered by Dornberger et al. from Streptomyces noursei, and they have strong inhibitory effects on agricultural pathogenic fungi such as alfalfa root rot fungus and rice blast fungus. However, due to the unstable chemical structure of tetracycline A and B under sunlight, they are sensitive to ultraviolet radiation, which limits their direct application in agricultural production. Zhang et al. found that tetracycline A and B have good bactericidal effects on Aspergillus flavus at lower concentrations, with the lowest bactericidal concentrations being 3.13 and 12.56 \u03bc g\/mL, respectively. Experimental antimicrobial activity does not establish that a compound is free of adverse effects in mammals or authorized for use in food or feed. Those conclusions require substance-specific toxicology and an assessment of the intended use.<\/span> This article for the first time discovered tetracycline A and tetracycline B, which are highly effective antifungal compounds, from the Streptomyces strain rssa1 derived from coral in the South China Sea. As many studies have shown that they have good application prospects in the fields of medicine and agricultural disease control, this bacterium may be an important strain resource for developing efficient, low toxicity drugs and green biocontrol agents. This discovery also provides important clues for searching for actinomycete resources with medicinal and agricultural value from tropical marine organisms in China.<\/p>\n