Isolation And Molecular Characterization Of Biosurfactant Producing Bacteria From Marine Environments
Project no. 28427 · Status: Kapanmış (Yayın bekleniyor) · 2023
Summary
<p>Biosurfactants are amphiphilic compounds typically produced as secondary metabolites by microorganisms isolated from terrestrial environments contaminated with hydrocarbons. Today, various brands have started to emerge as biosurfactant producers, and studies are identifying strains and species with high stability targeted towards different sectors. In this thesis, the isolation and identification of biosurfactant-producing bacteria from the underexplored marine environment, and the development of an environmentally friendly alternative to synthetic surfactants, were aimed. In this context, seawater and sediment samples contaminated with oil spills were collected from 12 different locations in the İzmir region of the Aegean Sea. As a result of pre-enrichment of these samples, 55 pure bacterial cultures were isolated.</p><p>All isolated bacteria were screened for their biosurfactant production potential using oil spreading and emulsification activity (E24) tests. Based on the obtained results, 10 isolates that showed good performance in both tests with different characteristics were selected and molecular identification was performed according to the 16S rRNA gene region. As a result of sequence analysis, 5 isolates were identified as <em>Pseudoalteromona</em>s sp., 1 isolate as <em>Vreelandella</em> sp, 1 isolate as <em>Winogradskyella</em> sp., 1 isolate as <em>Cellulophaga lytica</em>, 1 isolate as <em>Tenacibaculum</em> sp., and 1 isolate as <em>Cobetia amphilect</em>i.</p><p>Standardization studies were conducted to enhance biosurfactant production yields for the selected <em>Cellulophaga lytica</em> KSK22 and <em>Tenacibaculum</em> sp. 1B1 strains. Optimal biosurfactant production for <em>Cellulophaga lytica</em> KSK22 was achieved with 1% soybean oil, 2% salt concentration, at pH 7, 27°C, after 3 days of incubation at 150 rpm. For <em>Tenacibaculu</em>m sp., 1B1 optimal biosurfactant production was achieved with 1% diesel oil, 2% salt concentration, at pH 8, 27°C, after 3 days of incubation at 150 rpm.</p><p>Keywords: Biosurfactant, marine, oil spreading, emulsification activity, bacteria, 16S rRNA</p>