Production and optimization of α-amylase from thermo-halophilic bacteria isolated from different local marine environments

Abstract Background Amylases are among the most important enzymes which are of great significance for biotechnology and have almost completely replaced chemical hydrolysis of starch in the starch processing industry. The present study was concerned with the production and optimization of extracellular α-amylase from Bacillus sp. NRC22017. Results The effect of various fermentation conditions on α-amylase production through shake-flask culture was investigated. Bacterial strain produces α-amylase was isolated from water in Wadi El-Natron. Based on microbiological, biochemical tests, and 16S rRNA gene sequences, the isolate was identified as Bacillus sp. NRC22017 and was later used for further studies. Maximum yield of α-amylase is 15.15 ± 0.47 U/ml from Bacillus sp. NRC22017; this strain is characterized with high temperature and high salinity in cultivated culture, and achieved maximum yield of α-amylase at pH 6.0 with inoculum size of 500 μl at 45 °C and aerobically incubation period of 72 h. The optimum volume of the fermentation medium was found to be 20 ml in 100 ml Erlenmeyer flask; the best starch and meat extract plus peptone concentration that provided the highest enzyme production from Bacillus sp. NRC22017 were found to be 2% and 1.05% (w/v) respectively. Conclusion Enzyme production was higher after optimizing the production conditions as compared to the basal medium

Modeling and in-vivo evaluation of fibrinolytic enzyme produced by Bacillus subtilis Egy under solid state fermentation

Blood clot formation increases cases of myocardial infarction (AMI) and stroke, thus urges directing much research works for treatment and prevention of the causes. One of these directions is the microbial production of fibrinolytic enzymes as thrombolytic agents. In the current work, Bacillus subtilis Egy has been used for enzyme production under solid state fermentation. Among twelve nutrient meals in addition to wheat bran as a control fodder yeast yielded the highest enzyme activity reaching 114U/g. Applying statistical model for optimization of enzyme production revealed that 3.6%, fodder yeast; 40%, moisture content; 6 days, incubation period and 2%, inoculum size were the optimum conditions for maximum fibrinolytic enzyme production (141.02 U/g) by Bacillus subtilis Egy under solid-state fermentation The model was significant and data were experimentally validated. The produced fibrinolytic enzyme was evaluated for in vitro and in vivo cytotoxicity. In-vivo examination of the enzyme resulted in no mortality during the first 24 h after treatment. After 14 days, the results revealed no significant changes detected in hematological parameters (RBCs, MCV, hemoglobin except WBCs which showed an increase for both sexes. Histopathological examination of liver and kidney of rats received oral and subcutaneous treatments showed normal architecture. The data showed the applicability of the produced enzyme for the treatment of blood clot with no significant effect on living cells or on physiological functions