Çal Mağarası toprak mikrobiyal çeşitliliğindeki biyoteknolojik potansiyelin metagenomik analizi

Öz

Türkiye henüz araştırılmamış ve mikrobiyal çeşitliliği belirlenmemiş çok sayıda karstik mağaraya sahiptir. Bu mağaraların biyoçeşitlilik karakterizasyonu henüz moleküler bakış açısıyla ele alınarak sistematik bir şekilde incelenmemiştir. Trabzon’da yer alan Çal Mağarası önemli karstik mağaralardan biridir. Bu çalışmada Çal Mağarası’nın gen kaynaklarının biyoteknolojik potansiyelini değerlendirmek amacıyla, mağaranın mikrobiyal çeşitliliği ilk kez metagenomik yaklaşım ile araştırılmıştır. Detaylı taksonomik sınıflandırma 16S rRNA gibi sadece prokaryotları hedef alan spesifik bir markör gen yerine tüm çevresel genomların dizilenmesi ile gerçekleştirilmiştir. Taksonomik analize göre Çal Mağarası toprağındaki mikrobiyal çeşitliliğin %98’ni bakteriler, %2’sini ökaryotlar, %0.3’ünü arkealar ve %0.01’ini virüsler temsil etmektedir. Sonuçlar, Çal Mağarası toprak örneğinde temsil edilen 31 farklı bakteri filumunun %65’inin Actinobacteria ve %31’inin Proteobacteria olduğunu göstermektedir. Bunlar arasında en baskın bakteri cinsi Streptomyces olarak tespit edilmiştir. %2’lik ökaryotik popülasyon arasında en geniş filum Ascomycota’dır ve bu filumun toprak örneği içindeki en yaygın temsilcisinin Sordariomycetes olduğu görülmüştür. Arkeaların %77’sinin Halobacteria olduğu belirlenmiştir. Çal Mağarası toprağında yaşayan en yaygın virüs sınıfının Caudovirales olduğu ortaya çıkmıştır. Toplam okumaların %91.61’i için ise herhangi bir spesifik sınıflandırma yapılamamıştır. Sınıflandırılmış ve sınıflandırılmamış tüm verilere bakıldığında Çal Mağarası’nda klasik mikrobiyoloji teknikleriyle tanımlanamayacak olan çok büyük bir mikrobiyal biyoçeşitliliğin olduğunu ve bu mikrobiyal çeşitliliğin biyoteknolojik uygulamalarda kullanılacak yeni enzim ve biyoaktif bileşenlerin keşfi için umut verici bir gen kaynağı sağladığı doğrulanmaktadır.

Anahtar Kelimeler

• Aktinobakteriler
• Mağara Toprağı
• Metagenomik
• Proteobakteriler
• Taksonomik sınıflandırma

Metagenomic analysis of the microbial community in Çal Cave soil to elucidate biotechnological potential

Öz

Turkey has a great number of karstic caves which are unexplored and have unknown microbial diversity. The biodiversity characterisation of these caves has not yet been systematically studied from the molecular point of view. Çal Cave in Trabzon, Turkey is one of the important karstic caves. In the present study, a metagenomic approach was used to explore the microbial diversity of Çal Cave for the first time to assess the potential of gene sources. Detailed taxonomic profiling was defined by sequencing all environmental genomes instead of a specific marker gene such as 16S rRNA which only targets prokaryotes. Taxonomic analysis revealed that the Çal Cave soil sample was represented as 98% Bacteria, 2% Eukaryota, 0.3% Archaea, and 0.01% Virus. Results showed that, the 31 distinct bacterial phyla represented in the Çal Cave soil sample were dominated by Actinobacteria (65%) and Proteobacteria (31%). The most dominant bacterial genus was Streptomyces. Among the 2% Eukaryotic population, the largest phylum was Ascomycota and it was mostly represented as Sordariomycetes. It was determined that 77% of Archaea was Halobacteria. The most abundant class of viruses dwelling in Çal Cave was Caudovirales. 91.61% of total readings could not be classified into any specific kingdom. Overall, classified and unclassified data verify that there exists vast microbial biodiversity in Çal Cave which could not be identified with classical microbiology techniques, and this microbial diversity provides a promising gene source for novel enzyme and bioactive compounds to be used in biotechnological applications.

Anahtar Kelimeler

• Actinobacteria
• Cave soil
• Metagenomics
• Proteobacteria
• Taxonomic profiling

Kaynakça

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