İzmir Çamaltı tuzlasından izole edilen halofilik mikroalglerin moleküler ve morfolojik taksonomisi ile stres faktörlerine fizyolojik yanıtları
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Dosyalar
Tarih
2018
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Yayıncı
Bursa Teknik Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Halofilik ve halotolerant mikroorganizmalar yüksek tuz derişimlerine toleranslarından ötürü biyoteknolojinin çeşitli alanlarında yoğun üretim için uygundur. Yüksek tuz derişimleri mikrobiyal kontaminasyonu ve tatlı su kullanımını azalttığı gibi, bu tuzluluklarda yaşayan mikroorganizmaların benzersiz metabolitleri de olabilmektedir. Bu doğrultuda tez çalışmasında, İzmir Çamaltı Tuzlası'ndan izole edilmiş 20 mikroalg suşunun öncelikle genetik ve morfolojik özellikleri belirlenerek hangi türlere ait oldukları belirlenmiştir. Genetik ve morfolojik farklılık gösteren suşlardan 9'u tuzluluk tolerans deneylerine tabii tutulmuş; farklı tuzluluklarda büyüme ve total karotenoid üretimleri incelenmiştir. Bu deneylerden seçilen ve genetik farklılık gösteren 5 suş ise sıcaklık, tuzluluk ve ışık yoğunluğunun etkilerinin faktöriyel tasarımla incelendiği büyüme deneylerine tabii tutulmuştur. Böylece tez çalışmasında kullanılan halofilik mikroalg suşlarından biyoteknolojide kullanım ve yoğun üretim için en uygun potansiyele sahip olanlar belirlenmiştir. Tez çalışmasında kullanılan Dunaliella suşları boy x en aralıklarına göre büyük (8-20 µm x 6-18 µm) orta (4-12 µm x 3-10 µm) ve küçük (4-10 µm x 3-7 µm) formlardan oluşmuştur. Morfolojik özelliklerine göre üç gruba ayrılan bu suşlar, internal transcribed spacer (ITS) gen dizilerinin filogenetik analizinde de üç gruba ayrılmış ve büyük formlar Dunaliella salina, küçük formlar ise D. viridis benzeri olarak tanımlanmıştır. Orta boyuttaki suşların ITS gen dizileri, Dunaliella taksonomisi ve sistematiğindeki problemlerden ötürü, tür bazında tanımlama yapmaya yeterli olmamıştır. Genetik ve morfolojk farklılığa sahip 9 Dunaliella suşu 7 farklı tuzluluğu da (37 ppt-175 ppt) tolere edebilmiş, ancak farklı büyüme eğrilerine sahip olmuştur. Bu deneylerde en yüksek total karotenoid üretimi diğer suşlardan 2-5 kat fazla üretime sahip D. salina AQUAMEB-21 suşunda görülmüştür. Buradan seçilen 5 suşun 27 farklı sıcaklık, tuzluluk ve ışık yoğunluğu kombinasyonuna tabii tutulduğu büyüme deneylerinde ise suşlarda farklı tuzluluk ve sıcaklık optimumları tespit edilse de, en iyi büyüme değerleri yüksek ışık yoğunluklarında (150 ve 300 µmol. foton.m-2.s-1) görülmüştür. Her suş için optimum koşullarda elde edilen biyomas değerleri birbirine yakındır ve her biri farklı özelliklerine göre (Ör: pigment, protein, yağ asidi üretimi) biyoteknolojide kullanım potansiyeline sahiptir.
Halophilic and halotolerant microorganisms are suitable candidates for use in mass production in various biotechnological fields due to their tolerances to high salinities. Highly saline conditions do not only reduce microbial contamination and freshwater use, but microorganisms living in these conditions may have unique metabolites. Accordingly, in this thesis study, genetic and morphological characteristics of 20 microalgae strains isolated from İzmir Çamaltı saltern were determined to identify their species. Nine strains showing genetic and morphological variations were chosen to test their salinity tolerances, to determine their growth and total carotenoid production in various salinity levels. Five strains with genetic and morphological differences and chosen from these experiments were further grown in a factorial design experiment testing the effects of salinity, temperature and light intensity. Therefore halophilic microalgae strains with the best potential to be used in biotechnology and mass production were determined in this thesis study. Dunaliella strains used in this work were grouped into three forms based on their length x width ranges: Big forms (8-20 µm x 6-18 µm), medium forms ((4-12 µm x 3-10 µm), and small forms (4-10 µm x 3-7 µm). These strains, grouped into three according to their morphological characters, also clustered into three groups based on the sequences of their internal transcribed spacer genes. Big forms were identified as Dunaliella salina, and small forms were identified as D. viridis-like. However, due to inherent problems associated with Dunaliella taxonomy and systematics, ITS gene sequences were not enough to assign species names to medium forms. Nine Dunaliella strains with genetic and morphological differences tolerated all seven salinity levels (37 ppt to 175 ppt) tested, however with different growth curves. In these experiments highest total carotenoid production was seen in D. salina AQUAMEB-21 with 2 to 5 times more production than other strains. Further selected 5 strains were grown in 27 different combinations of salinity, temperature and light intensity. Although results suggested different salinity and temperature optima for these strains, best growth was always observed in high light intensities (150 ve 300 µmol. foton.m-2.s-1). For all tested strains, biomass values obtained under optimal conditions were similar and each of these strains have the potential to be used in biotechnology for their various characteristics such as pigment, protein or fatty acid production.
Halophilic and halotolerant microorganisms are suitable candidates for use in mass production in various biotechnological fields due to their tolerances to high salinities. Highly saline conditions do not only reduce microbial contamination and freshwater use, but microorganisms living in these conditions may have unique metabolites. Accordingly, in this thesis study, genetic and morphological characteristics of 20 microalgae strains isolated from İzmir Çamaltı saltern were determined to identify their species. Nine strains showing genetic and morphological variations were chosen to test their salinity tolerances, to determine their growth and total carotenoid production in various salinity levels. Five strains with genetic and morphological differences and chosen from these experiments were further grown in a factorial design experiment testing the effects of salinity, temperature and light intensity. Therefore halophilic microalgae strains with the best potential to be used in biotechnology and mass production were determined in this thesis study. Dunaliella strains used in this work were grouped into three forms based on their length x width ranges: Big forms (8-20 µm x 6-18 µm), medium forms ((4-12 µm x 3-10 µm), and small forms (4-10 µm x 3-7 µm). These strains, grouped into three according to their morphological characters, also clustered into three groups based on the sequences of their internal transcribed spacer genes. Big forms were identified as Dunaliella salina, and small forms were identified as D. viridis-like. However, due to inherent problems associated with Dunaliella taxonomy and systematics, ITS gene sequences were not enough to assign species names to medium forms. Nine Dunaliella strains with genetic and morphological differences tolerated all seven salinity levels (37 ppt to 175 ppt) tested, however with different growth curves. In these experiments highest total carotenoid production was seen in D. salina AQUAMEB-21 with 2 to 5 times more production than other strains. Further selected 5 strains were grown in 27 different combinations of salinity, temperature and light intensity. Although results suggested different salinity and temperature optima for these strains, best growth was always observed in high light intensities (150 ve 300 µmol. foton.m-2.s-1). For all tested strains, biomass values obtained under optimal conditions were similar and each of these strains have the potential to be used in biotechnology for their various characteristics such as pigment, protein or fatty acid production.
Açıklama
Anahtar Kelimeler
Biyoteknoloji, Biotechnology, Genetik, Genetics, Morfoloji, Morphology, Dunaliella, Dunaliella, Faktöriyel tasarım, Factorial design, Moleküler sistematik, Molecular systematic
