Characterization of autochthonous microorganisms with high ability to degrade hydrocarbons from oil contaminated soils

Abstract

Kako potreba za naftom i njenim proizvodima raste, tako dolazi i do sve češćih onečišćenja okoliša prilikom raznih aktivnosti tijekom njezine uporabe. Zbog svog negativnog utjecaja na sav živi svijet, naftne ugljikovodike nužno je ukloniti iz okoliša. Jedan od postupaka za remedijaciju tla onečišćenog naftom je bioremedijacija. Bioremedijacija je okolišno i ekonomski prihvatljiv postupak za uklanjanje prisutnog onečišćenja u kojem mikroorganizmi i njihovi enzimi imaju ključnu ulogu. Kako bi se povećala učinkovitost bioremedijacije potrebno je selektirati mikroorganizme koji pokazuju afinitet za razgradnju naftnih ugljikovodika. U ovom radu provedena je izolacija, identifikacija i karakterizacija autohtonih mikrobnih kultura iz uzorka tla onečišćenog sirovom naftom u šaržnim uvjetima u periodu 28 dana. Dobivene vrijednosti CFU su se kretale u rangu od 1,20 × 10^7 do 1,15 × 10^9/g tla. Rezultati pokazuju da je aktivnost bakterija i gljiva bila najveća pri pH-vrijednosti 7,25 i 6,5. Na temelju morfologije, biokemijskih testova i MALDI TOF analize identificirane su bakterijske vrste: Bacillus megaterium, Bacillus licheniformis, Bacillus cereus i Pseudomonas chlororaphis.As the demand for petroleum and petroleum products increases, so does the pollution caused by the various activities associated with the use of petroleum. Because of their negative impact on all living things, petroleum hydrocarbons must be removed from the environment. One of the methods of remediation of oil polluted soil is bioremediation. Bioremediation is an ecologically and economically viable method of removing contaminated sites, in which microorganisms and their enzymes play a key role. In order to increase the efficiency of bioremediation, it is necessary to select microorganisms that have affinity for degradation of petroleum hydrocarbons. In this work, the isolation, identification and characterization of autochthonous microbial cultures from a petroleum contaminated soil sample was carried out under batch conditions over a period of 28 days. Determinated CFU values ranged from 1.20 × 10^7 to 1.15 × 10^9/g soil. The results show that the activity of bacteria and fungi was highest at pH 7.25 and 6.5. Based on morphology, biochemical tests and analysis of MALDI TOF, bacterial species were identified: Bacillus megaterium, Bacillus licheniformis, Bacillus cereus, and Pseudomonas chlororaphis