Phylogenetic Identification of Two Extremely Halophilic Archaeon Isolated from Raw Hide and Investigation of Their Lipolytic Activities

This research serves two different purposes. Primarily, two extremely halophilic archaeons were isolated from salted raw hide samples and were phylogenetically identified by 16S rRNA sequence analyses. It was determined that isolate 1 shared similarities with Halomicrobium zhouii strain 144 and isolate 2 with Haloarchaeon strain 129. These results were substantiated by some phenotypic analyses. Both strains displayed Gram-negative reactions and they were susceptible to the antibiotics bacitracin and novobiocin. It was qualitatively determined that they have lipolytic activity. Secondly, esterase and lipase enzyme activity conditions of the two archaea were also determined in the current study to evaluate industrial applicability of these enzymes. For the identification of quantitative esterase and lipase activities of both strains, p-nitrophenyl butyrate and p-nitrophenyl laurate substrates were used, respectively, and their activities were measured on a daily basis. After the quantitative and qualitative determination of esterase and lipase activities, esterase and lipase activities were determined at different temperatures (4-60°C), pH levels (4-11pH) and in NaCl concentrations (0-5.5M). According to daily enzyme activity results, the highest esterase and lipase values for isolate 1 were found to be 4 U/ml and 1 U/ml, respectively, on the 4th day and for isolate 2 to be 2.7 U/ml and 1.9 U/ml, respectively, on the 3rd day. Furthermore, the maximum esterase activity for isolate 1 was elicited at 35°C, pH 8 and in 2.5 M NaCl, and for isolate 2 at 35°C, pH 7 and in 3 M NaCl. Moreover, the maximum lipase activity for isolate 1 was explored at 40°C, pH 7.0 and 2.0-3.5 M NaCl, and for isolate 2 at 35°C, pH 7.5 and in 2 M NaCl. Optimal conditions for both extreme halophilic Archaea was determined as the data may be considered for the production of industrial enzymes. Therefore, this research is an exemplary study as well as a small-scoped survey which includes the two goals mentioned above and only focuses on two archaea on salted raw hides.