Hydrolytic Enzyme Production by Thermophilic Bacteria Isolated from Saudi Hot Springs

Autor: Alrumman Sulaiman, Mostafa Yasser S. Mostafa, Al-Qahtani Shekha, Taha Tarek H. Taha
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Open Life Sciences, Vol 13, Iss 1, Pp 470-480 (2018)
Druh dokumentu: article
ISSN: 2391-5412
DOI: 10.1515/biol-2018-0056
Popis: Hydrolytic enzyme production by thermophilic bacteria isolated from hot springs in the southern region of Saudi Arabia was investigated. The physical and chemical properties of the hot springs prove to be an important environment for hydrolytic-enzyme-producing thermophilic bacteria. Eighty-four bacterial isolates were obtained from three hot springs: Al-Majardah, Al-Khubah and Al-Ardah. Screening of the isolates for enzyme production indicated that 78 isolates showed activity for one or more enzymes. Molecular identification and phylogenic analysis of selected promising isolates confirmed the identity of the isolates as Bacillus aerius, Bacillus licheniformis and Bacillus sonorensis, which have potential to produce the target enzymes α-amylase, protease and lipase, respectively. Optimization of hydrolytic enzyme production by bacterial strains was investigated using kitchen waste as a cheap carbon energy source. Maximum enzyme production was achieved after 72 hours of incubation at the beginning of the stationary phase of growth. Enzyme production was dependent on the initial pH value in the range of pH 7.5-8.5 and an optimal incubation temperature of between 55-60°C. Enzyme production increased gradually in proportion to the kitchen waste concentration; whereas maximum lipase production was gained at 5.0% (w/v) kitchen waste, 7.0% (w/v) of waste was optimal for both α-amylase and protease productivity. The results indicated that hot springs in Saudi Arabia are a substantial source of thermophilic bacteria producing industrially important enzymes using cheap and unexploited waste.
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