Antibiyotikler mikroorganizmalar taraf ndan üretilen, yüksek seyreltmelerde di er
mikroorganizmalar n büyümesine antagonistik etki yapan maddeler olarak tan mlanmaktad r.
Çoklu ilaç direncine sahip bakteriler birden fazla antibiyoti e dirençli olanlard r ve
mikroorganizmalar n dirençli hale geldikleri antibiyotiklerden art k etkilenmezler.
Çal mam zda çe itli habitatlardan 414 endospor olu turan basil izole edilmi tir. Bu
izolatlar n aktif metabolit aç s ndan tarama i lemi iki a amada gerçekle tirilmi tir. Birinci
a amada piece agar yöntemi kullan lm ve ikinci a amada ise klinik izolatlara kar
gösterdi i aktivite piece agar ve disk difüzyon yöntemine göre yap lm t r. %kinci taramada
izolatlar n % 23’ü en az ndan bir klinik izolata kar aktivite göstermi tir.
Seçilen izolatlar VITEK sistem ile identifiye edildi inde 4’ü Bacillus subtilis, 4’ü B.
cereus, 2’si B. amyloliquefaciens, Ya asidi profillerine (FAME) göre identifiye edildi inde
7’si B. cereus, 1’i B. amyloliquefaciens, 2’si Paenibacillus macerans olarak tan mlanm t r.
S cakl k, çalkalama h z , pH, karbon kayna , azot kayna ve mineral madde tipinin
seçilen izolat n geli imi ve antibakteriyal ve antifungal metabolit üretimi üzerine etkisi
responce surface modeline göre incelenmi tir. 200 rpm çalklama h z nda, 35-42 °C’de ve pH
7 de en fazla hücre geli imi ve metabolit üretimi görülmü tür. Modele göre karbon
kayna n n en önemli faktör oldu u bulunmu tur.
Endasimbiyotik stain (P. macerans) taraf ndan üretilen metabolitler etil asetat ile
ekstrakte edilerek ince tabaka kromotografisi ve kolon kromoto rafisi ile safla t r lm t r.
Aktif maddenin etkisi minimum inhibisyon konsantrasyonu ve minimum sidal
konsantrasyonu ile de erlendirilmi tir.
Antibiotics have been defined as substances produced by microorganisms that,
in high dilution, are antagonistic to the growth or life of other microorganisms. Multi
drug resistant bacteria are those that are resistant to more than one antibiotic, meaning
that the microorganisms are no longer affected by the antibiotics to which they have
become resistant.
In this study a total of 414 endospor forming bacilli were isolated from different
habitats. Screening for biological active metabolite was carried out two stage. In first
screening, 221 active isoltes were obtained using piece agar method, in terms of their
general inhibition effects to some test bacteria, yeast and molds. Second screening of
the isolates was carried out disc diffusion and piece agar method in terms of their
general inhibition aganist to some multidrug resistant microorganisms. 23% of the
isolates shown inhibition effects aganist at least one multi drug resistant
microorganisms.
Ten endospor forming bacillus strains selected were identified as 4 Bacillus
subtilis, 4 B. cereus and 2 B. amyloliquefaciens by VITEC system and as 7 B. cereus, 1
B. amyloliquefaciens and 2 Paenibacillus macerans according to faty acids profiles
(FAME).
A surface responce model was used to study the effect of pH, temperature,
agitation, carbon source, nitrojen source and mineral matter source on growth of P.
macerans and its antifungal and antibacterial metabolite production. 200 rpm agitation,
temperature 35-42°C’de and pH 7 favoured cell growth and prouction metabolite.
According to the model it was found that carbon source was the most important factor.
The metabolites produced by the endosymbiotic strain (P. macerans) were
extracted with ethyl acetate. Active metabolite was isolated and purified by thin layer
chromotogrphy and column chromotography. The effect of active substans on test
microorganisms was evaluated by minimum inhibition consentration ve minimum cidal
concentration.
