Fungal Population Analysis from Hydrocarbons Contaminated Soil of Taq-taq Oil Field/ Koya City Using Metagenomics Technique

One of the most significant concerns about the environment nowadays is the presence of contaminated soils caused by petroleum. Within the span of the past twenty years, our understanding of the microbial diversity present in a variety of diverse complicated ecosystems has been significantly advanced as a direct result of the application of molecular approaches. Metagenomic analysis was conducted using high-throughput sequencing technology, targeting 18 subunit ribosomal ribonucleic acid amplicons via the Illumina-HiSeq platform. Soil samples were collected from various petroleum pollution sites, encompassing mixed mud and crude oil-contaminated soil, long-term asphalt-flanked or direct-contact soil, clean reference sites, and soil impacted solely by crude oil transportation of the Taq-taq/ Koya city oil field in Kurdistan Region was investigated. In general, an increase of microbial community richness and diversity was reported in soil contaminated with petroleum. This was determined by counting the number of operational taxonomic units (OTUs), performing principal coordinate analysis, and α (Chao1 and Shannon indices), and ß diversity. Microbial community structure was significantly altered as a result of crude oil contamination. At the phylum level, groups A and C was dominated by Ascomycota while long-term direct contact soil group B was dominated by Basidiomycota. Fungal species such as Saccharomyces cerevisiae, Chaetomium globosum, and Pichia kudriavzevii were prevalent in group C. albugo laibachii dominated in group D, Yarrowia lipolytica in group A and Rhodotorula_toruloides was dominated in group B. The biomarker taxa that were detected for the oil-contaminated soil and control soil were found using the LEfSe algorithm (Cladogram) and the LDA method. The results indicate that the most abundant biomarkers present in group B belong to the Basidiomycota phylum. Specifically, the Dipodascaceae family and the Yarrowia genus, which are associated with the Ascomycota phylum, exhibited LDA values exceeding 2. In conclusion, this study is an important first step in determining and understanding the fungal population of soil extensively contaminated with crude oils of the Taq-taq/Kurdistan Region of Iraq. The findings of this study could be employed in the bioremediation process as well as in the biotechnology industry.