Urmiye gölünden alınan örneklerde arseniğe dirençli bakterilerinizolasyonu, tanımlanması, fenotipik ve moleküler karakterizasyonu
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Dosyalar
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi, Fen Bilimleri Fakültesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Yeraltı sularının, nehirlerin ve tarımsal çiftliklerin yaygın arsenik kontaminasyonu, yaygın arsenik zehirlenmesine ve sonuç olarak sağlık ve ekonomi ile ilgili sorunlara yol açmaktadır. Dünya çapında milyonlarca insan arsenik kontaminasyonu ile tehdit altındadır, bu nedenle olası küresel felaketi önlemek için ciddi önlemler alınmalıdır. Son yıllarda, biyoremidasyon uygulamalarının yolunu açan bakteriyel arsenik detoksifikasyonu ve metabolizmasını anlamak için birçok çalışma yapılmıştır. Bu tez çalışmasında, arsenik dirençli bakterileri, kurumakta olan Urmiye gölün'den izole ve karakterize etmeye çalışılmıştır. İlk izolasyon için, 10mM arsenat ve % 7,5 NaCl içeren ve 9,5 pH'ya ayarlanan LB ortamı kullanılmıştır. Bakterilerin tanımlanması fenotipik ve genotipik çalışmalara dayanılarak gerçekleştirilmiştir. Elde edilen toplam on izolat için 16s rDNA analizi, tüm suşların esas olarak Bacillus cinsine ait olduğunu ortaya çıkarmıştır. Bazı suşlar için, arsenat ve arsenit maksimum tolerans konsantrasyonu yüksek değerlerde saptanmıştır, sırasıyla; 320mM ve 32mM. Bütün suşlarda arsenat redüktaz geni (arsC) tespit edilmiştir. arsB geni, Bacillus sp. S1, S8, S12 ve E15 suşları haricinde tüm suşlarda saptanmıştır. Solunum arsenat redüktaz (arrB) ve arsenit oksidazın (arxA) metabolik genleri izolatların hiçbirinde tanımlanamamıştır.
Extensive arsenic contamination of groundwater, rivers and agricultural farms has led to widespread arsenic poisoning and consequent problems associated with health and economy. Millions of people worldwide are threatened by arsenic contamination thus serious actions should be taken to prevent likely global calamity. In recent years many studies have been performed to understand bacterial arsenic detoxification and metobolism which paved the way for bioremediation applications. This thesis study attempted to isolate and characterize arsenic resistant bacteria from drying Urmia lake. LB medium containing 10mM arsenate and %7.5 NaCl adjusted at pH 9.5 was used for initial isolation. Identification of bacteria was carried out based on phenotypic and genotypic studies and ten isolates were selected. 16s rDNA analysis revealed that all strains were mainly belonged to Bacillus genus. For some of the strains, maximum tolerance concentration for either arsenate and arsenite was considerably high, 320mM and 32mM respectively. All of the strains harboured arsenate reductase gene (arsC). The arsB gene was identified in all strains except Bacillus sp. strains S1, S8, S12 and E15. The metabolic genes of respiratory arsenate reductase (arrB) and arsenite oxidase (arxA) were identified in none of isolates. This study could be remarkable of it's kind in Urmia lake because it is relatively the first study which has been done in Urmia lake. Current study could provide data for studies conducting bioremediation applications in order to prevent arsenic disaster in vicinal territories.
Extensive arsenic contamination of groundwater, rivers and agricultural farms has led to widespread arsenic poisoning and consequent problems associated with health and economy. Millions of people worldwide are threatened by arsenic contamination thus serious actions should be taken to prevent likely global calamity. In recent years many studies have been performed to understand bacterial arsenic detoxification and metobolism which paved the way for bioremediation applications. This thesis study attempted to isolate and characterize arsenic resistant bacteria from drying Urmia lake. LB medium containing 10mM arsenate and %7.5 NaCl adjusted at pH 9.5 was used for initial isolation. Identification of bacteria was carried out based on phenotypic and genotypic studies and ten isolates were selected. 16s rDNA analysis revealed that all strains were mainly belonged to Bacillus genus. For some of the strains, maximum tolerance concentration for either arsenate and arsenite was considerably high, 320mM and 32mM respectively. All of the strains harboured arsenate reductase gene (arsC). The arsB gene was identified in all strains except Bacillus sp. strains S1, S8, S12 and E15. The metabolic genes of respiratory arsenate reductase (arrB) and arsenite oxidase (arxA) were identified in none of isolates. This study could be remarkable of it's kind in Urmia lake because it is relatively the first study which has been done in Urmia lake. Current study could provide data for studies conducting bioremediation applications in order to prevent arsenic disaster in vicinal territories.
