Evaluation of Halobacterial Extracellular Hydrolytic Activities in Several Natural Saline and Hypersaline Lakes from Romania

Abstract

This work presents the evaluation of extracellular hydrolytic activities involved in the degrading of organic compounds from several natural salt lakes located in the southern part of Romania. The paper approaches the extracellular enzymatic decomposition activity in accordance with several physico-chemical parameters and microbial abundance. The chloride content was 13 g/l in Balta Albă salt lake, around 15 – 17 g/l in Amara salt lake, 80 g/l in Movila Miresei hypersaline lake and close to saturation, 252 g/l respectively in the case of Ocnele Mari hypersaline sample. The chemical composition revealed that salinity is due to compounds of sulphur, chloride and potassium in lakes Balta Alba and Amara. In Movila Miresei, potassium is replaced by sodium and in Ocnele Mari the salinity is due mainly to chloride and sodium. The enzyme α –glucosidase showed high values in the hypersaline lakes Movila Miresei and Ocnele Mari and a similar profile was recorded also for β-glucosidase. The activity of the enzyme alkaline phosphatase is directly correlated with the chloride content. The enzyme aminopeptidase showed high values if compared with previously mentioned enzymes.