Introduction: Bacteria in cold ecosystems play a vital role in biochemical cycles, the biodegradation of pollutants, and biotechnology. For this reason, the identification and evaluation of their extracellular enzymes have received a lot of attention in recent years. Materials and methods: In this study, 43 psychrophilic or psychrotolerant bacteria were characterized from alpine soils on different culture media. The ability to produce extracellular enzymes by these bacteria was studied. Results: These bacteria belonged to the four major phyla including Actinobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. A total of nine genera were identified among which Pseudomonas, Arthrobacter, and Bacillus were the most abundant. Discussion and conclusion: All of the obtained strains have the ability to produce at least one extracellular enzyme; proteolytic and amylolytic activities were the highest among these strains. Cellulase and pectinase activities were observed in 44 and 22 percentage of these strains. This study was the first report on psychrophilic and psychrotolerant bacteria in the Zagros Mountains (Oshtorankuh) and their extracellular enzyme production. The present study indicated that a wide range of bacteria in cold native ecosystems of Iran can be a suitable source for cold active enzymes.

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