Amylase is one of the most widely used enzymes in the industry. Cold environments are the most ubiquitous environments in the world that have been occupied by cold tolerant microorganisms. The enzymes of these microorganisms have a wide range of applications in various areas of biotechnology. The aim of this study was to isolate cold-active amylase producing bacteria. A total of 64 cold-toleran...

In this study, response surface methodology (RSM) based on central composite design (CCD) was applied for investigation of the effects of ultrasonic waves, temperature and solvent concentration on viscosity reduction of residue fuel oil (RFO). Ultrasonic irradiation was employed at low frequency of 24 kHz and power of 280 W. The results showed that the combination of ultrasonic waves and solven...

gelatin is a protein hydrocolloid. because of its unique characteristics such as gel forming, thickening, stabilizing, emulsifiing, foam and film forming, is widely used in food industries. in this research, in order to optimize the factors which affect enzymatic extraction method of gelatin ,the effects of three variables, enzyme concentrations(2-10 ppm), time(8-16 hours) and temperature(60-80...

background and objectives: lactobacillus delbrueckii ssp bulgaricus is widely used in dairy industries as a starter for yogurt production. this study was designed using response surface methodology (rsm) in 12 batch ph-controlled cultures of lactobacillus delbrueckii sub-ssp. bulgaricus for determining the effect of temperature and ph on the biomass production of a native strain of l. bulgaricu...

Response Surface Methodology (RSM) searches for the input combination that optimizes the simulation output. RSM treats the simulation model as a black box. Moreover, this paper assumes that simulation requires much computer time. In the first stages of its search, RSM locally fits first-order polynomials. Next, classic RSM uses steepest descent (SD); unfortunately, SD is scale dependent. Theref...