RESUMEN
Abstract Medicinal and aromatic plants have been widely using in folk medicine as antimicrobial, anti-inflammatory and antinociceptive agents. The aim of this study was to determine essential oil composition and antimicrobial activity of T. spicata, L. X Intermedia, S. macrantha and R. officinalis. Essential oil components of these plants were obtained by water vapor distillation method using Neo-Clevenger apparatus. Essential oil components were determined by gas chromatography-mass spectroscopy (GC-MS). The main components of these plants are carvacrol (74.26 %) and γ-terpinene (10.28%) in T. spicata, 1,8-cineol (32.48%), linalool (24.38%) and camphor (14.73%) in L. X Intermedia, p-cymene (56.70%), carvacrol (10.96 %) in S. macrantha and camphor (18.26 %), α-pinene (15.51%), 1,8-cineole (11.86%) and borneol (10.39%) in R. officinalis were determined. T. spicata and S. macrantha showed strong effects against three microorganisms. L. X Intermedia and R. officinalis showed strong activity against Candida albicans, while they had moderate effects against Staphylococcus aureus, Escherichia coli.
RESUMEN
A thermostable and detergent-stable α-amylase from a newly isolated Anoxybacillus sp. AH1 was purified and characterized. Maximum enzyme production (1874.8 U/mL) was obtained at 24 h of incubation. The amylase was purified by using Sephadex G-75 gel filtration, after which an 18-fold increase in specific activity and a yield of 9% were achieved. The molecular mass of the purified enzyme was estimated at 85 kDa by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature values of the enzyme were 7.0 and 60 °C, respectively. The enzyme was highly stable in the presence of 30% glycerol, retaining 85% of its original activity at 60 °C within 120 min. Km and vmax values were 0.102 µmol and 0.929 µmol/min, respectively, using Lineweaver-Burk plot. The enzyme activity was increased by various detergents, but it was significantly inhibited in the presence of urea. Mg2+ and Ca2+ also significantly activated α-amylase, while Zn2+, Cu2+ and metal ion chelators ethylenediaminetetraacetic acid (EDTA) and 1,10-phenanthroline (phen) greatly inhibited the enzyme activity. α-Amylase activity was enhanced by ß-mercaptoethanol (ß-ME) and dithiothreitol (DTT) to a great extent, but inhibited by p-chloromercuribenzoic acid (PCMB). Iodoacetamide (IAA) and N-ethylmaleimide (NEM) had a slight, whereas phenylmethylsulfonyl fluoride (PMSF) had a strong inhibitory effect on the amylase activity.
