Determination of important enzymes and antimicrobial resistances of gram-positive haloalkaliphilic bacteria isolated from Salda Lake

As an extreme environment, soda lakes harbor various haloalkaliphilic microorganisms. Salda Lake is one of the natural soda lake (pH˃9) in Turkey. Haloalkaliphiles are unique microorganisms in their ability to live in high alkaline and high saline conditions, and play an important role in biodegradation and bioremediation of hydrocarbons. Hence, the aims of this study were to isolate haloalkaliphilic bacteria from water sample of Salda Lake, to identify these isolates by both conventional and molecular methods, to screen their industrially important enzymes, and to investigate their antimicrobial resistance profiles. Six isolates were identified as Bacillus horneckiae, Bacillus subtilis, Bacillus paramycoides, Bacillus pumilus, Staphylococcus epidermidis, Bacillus haynesii according to 16S rRNA gene sequencing analysis. The industrially important enzymes (amylase, cellulase, pullulanase, lipase, urease, protease, caseinase, oxidase, catalase) were produced by haloalkaliphilic isolates. These enzymes maybe used in alkaline and saline industrial processes. Although Bacillus subtilis was susceptible to all antibiotics, other isolates showed resistance to at least one antibiotic. The resistance against antibiotics were found as ampicillin/sulbactam 83%, amoxycillin/clavulanic acid 83%, ampicillin 67%, mupirocin 67%, chloramphenicol 50%, tetracycline 50%, imipenem 50%, meropenem 50%, cefadroxil 17%. These bacteria may have develope resistance to antibiotics that entering their natural environment in different ways.