Isolation and characterization of a thermostable lipase from Bacillus thermoamylovorans NB501
| Autor: | Chihaya Yamada, Takatoshi Arakawa, Kota Sawano, Shinya Fushinobu, Noriyasu Iwase, Masaki Matsuoka, Shigeo Nishida |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
chemistry.chemical_classification food.ingredient biology Strain (chemistry) Molecular mass Thermophile Applied Microbiology and Biotechnology Microbiology Soybean oil 03 medical and health sciences 030104 developmental biology food Enzyme chemistry biology.protein Fermentation Food science Lipase Thermostability |
| Zdroj: | The Journal of General and Applied Microbiology. 62:313-319 |
| ISSN: | 1349-8037 0022-1260 |
| DOI: | 10.2323/jgam.2016.06.002 |
| Popis: | Two thermophilic bacterial strains, Bacillus thermoamylovorans NB501 and NB502, were isolated from a high-temperature aerobic fermentation reactor system that processes tofu refuse (okara) in the presence of used soybean oil. We cloned a lipase gene from strain NB501, which secretes a thermophilic lipase. The biochemical characteristics of the recombinant enzyme (Lip501r) were elucidated. Lip501r is monomeric in solution with an apparent molecular mass of 38 kDa on SDS-PAGE. The optimal pH and apparent optimal temperature of Lip501r were 8 and 60°C, respectively. Supplementation of 5 mM Ca2+ enhanced the thermostability, and the enzyme retained 56% of its activity for 30 min at 50°C. Lip501r was active on a wide range of substrates with different lengths of p-nitrophenyl (pNP) esters, and showed a remarkably higher activity with pNP-myristate. The Km and Vmax values for pNP-butyrate in the presence of 5 mM CaCl2 were 1.8 mM and 220 units/mg, respectively. The possible industrial use of the thermophilic lipase in modifying edible oil was explored by examining the degradation of soybean oil. A TLC analysis of the degraded products indicated that Lip501r is an 1,3-position specific lipase. A homology modeling study revealed that helix α6 in the lid domain of NB501 lipase was shorter than that of lipases from the Geobacillus group. |
| Databáze: | OpenAIRE |
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