Determination of hydrolytic capabilities of halophilic archaea isolated from hides and skins and their phenotypic and phylogenetic identification

In this research, we aimed to isolate extremely halophilic archaea from salted hides and skins, to determine the capacities of their hydrolytic enzymes, and to identify them by using phenotypic and molecular methods.Domestic and imported salted hide samples obtained from eight different sources were used as the research material. 186 extremely halophilic microorganisms were isolated from salted raw hides. Some biochemical, antibiotic sensitivity, pH, NaCl, temperature tolerance and quantitative and qualitative hydrolytic enzyme tests were performed on these isolates.100% of the isolates were found to be susceptible to bacitracin and novobiocin. It was figured out from the qualitative enzyme activity results that 23 isolates (12 %) showed caseinase, 106 isolates (57 %) gelatinase activities, while 21 isolates (11 %) display amylase, 65 isolates (35 %) esterase and 33 isolates (18 %) lipase activity. Caseinase, ceratinase, collagenase, esterase and lipase enzyme activities of some isolates, showing qualitative enzyme activity, were quantitatively measured. It was found that isolate 150 had 9.2 U/ml caseinase, 0.6 U/ml ceratinase, 1.7 U/ml collagenase activity, isolate 140 had 51 U/ml esterase activity, isolate 505 had 33.8 U/ml lipase activities which is higher than other isolates.In our study, taking into account the phenotypic findings of the research, 34 of 186 isolates were identified by 16S rRNA sequence analysis. According to these results, 34 extremely halophilic archaea were identified, including 10 isolates Natrialba aegyptia 40, 5 isolates Halococcus thailandensis, 4 isolates Natrinema pallidum R-fish, 2 isolates Halococcus dombrowskii H4, 2 isolates Halovivax asiaticus, ve 1 isolate each Halovivax sp. E107, Halococcus morrhua, Uncultured haloarchaeon clone YA32, Natronococcus sp. F30AI, Halorubrum sp. CH3, Halomicrobium zhouii, Natronococcus jeotgali, Haloterrigena thermotolerans Z4, Halococcus qingdaonensis, Natrinema versiforme XF10, Halobacterium noricense A1. Detecting Natrialba aegyptia 40 in 6 of 8 hide samples showed that this strain is widely found in hide samples.As a result, in our study 16 different strain of extremely halophilic archaea were identified from 34 isolates. Two of these were obtained from salted raw hides in previous studies, but other 14 strains were identified for first time from salted raw hide in our study. Research results are expected to contribute to other studies and solving microbial problems in leather industry.Keywords: Salted Raw Hide, Extremely Halophilic Archaea, Protease, Keratinase, Collagenase, Lipase, Esterase, 16S rRNA sequence analysis.