Screening and Identification of Thermotolerant and Osmotolerant Bacillus amyloliquefaciens BKHE Isolated from Kinema of Eastern Nepal for Alkaline Protease Production

Alkaline protease is one of the most important industrial enzymes which are excessively used in the detergent industry, food industry, feed industry, pharmaceutical industry, leather industry, etc. 60% of the produced alkaline protease is consumed by the detergent industry alone. In the present study, bacterial isolates that can produce alkaline protease for purpose of bio-detergent were screened among the isolates isolated from kinema (an alkaline fermented food of eastern Nepal). Selected bacterial isolates were further screened for hemolysis activity and the production of other hydrolytic enzymes. Four bacterial isolates selected were tested for their capacity to produce alkaline protease in five different fermentation mediums. Isolate BKHE produces a high amount of alkaline protease (0.4705 ± 0.035 U/mL/min) in fermentation medium M2 (sucrose, 11 g/L; yeast extract, 5 g/L; and KNO3, 5.2 g/l, pH 9). The selected isolate was identified as Bacillus amyloliquefaciens BKHE based on 16S rRNA sequencing and phenotypic features. This bacterial strain was also found to be thermotolerant (confluent growth at 50°C) and salt tolerant up to 10% NaCl concentration. With its versatile ability, bacterial isolate or purified enzymes have potential applications in the food and detergent industry

α-Amylase Inhibition, Antioxidant Activity and Phytochemical Analysis of Calotropis gigantea (L.) Dryand

Introduction: Antioxidant and α-Amylase inhibitory activity of methanolic extract of Calotropis gigantea (L.) Dryand leaves were evaluated.&#x0D; Methods: The antioxidant activity was evaluated by DPPH assay. The extract was fractionated in Silica gel loaded column chromatography (CC). All fractions were evaluated for their purity by TLC. Out of 11 fractions from CC, one fraction was analyzed by Gas Chromatography-Mass Spectrometry (GC-MS).&#x0D; Results: The antioxidant activity of methanolic extract was found satisfactory (IC50268.80 µg/ml) as compared with ascorbic acid (141.82 µg/ml). TLC of a fractions showed a compound at Rf value at 0.45 in toluene: chloroform: methanol with mobile phase ratio 7:2:1 respectively.&#x0D; Conclusions: Total 17 compounds were identified by GC-MS of ethyl acetate fraction and 5-hydroxyl methyl furfural was major furan compound (59.49%). α-Amylase inhibitory activity of the same fraction showed IC50 value of 0.94 mg/ ml. The Nepalese originated C. gigentea (L.) Dryand possesses antioxidant and α-Amylase inhibitory property.</jats:p