Screening and isolation of amylolytic thermophiles from Hulu Langat Hot Spring, Selangor

摘要

Thermophiles are microorganisms that inhabit at extremely high temperature environment. Thermoenzymes from thermophilic microorganisms are heat-stable, able to withstand denaturants of extremely acidic and alkaline conditions, and thus, have a considerable potential for many industrial applications. The aim of this study was to isolate and characterize amylolytic thermophiles. Two isolates of amylase producing thermophiles namely MA7K1T55C4 and MA8K2T55C8 were isolated previously from Dusun Tua Hot Spring, Selangor. The pH of the hot springs within the area was recorded to be slightly alkaline with temperature ranging from 55 ˚C to 70 ˚C. Two media were used to inoculate these samples, which were general enrichment medium, and selective medium that contains starch as the carbon source. Colonies with white abundant growth, irregular margin and glossy smooth were obtained from both samples. These isolates were subjected to gene amplification by PCR using a pair of universal primer to obtain their 16S rDNA gene. Obtained gene was sequenced and analyzed using bioinformatics tools. They were found to be from the genus Brevibacillus, spore-forming type; Gram's positive, aerobic, rod-shaped and capable of producing amylase. Bioinformatics analysis shown that isolate MA7K1T55C4 and isolate MA8K2T55C8 had the highest homology with the Brevibacillus berstelensis with the score of 99%.