Isolation of GSH from Baker Yeast by Ultrasonic method

The purpose of this study was to determine the effect of operating parameters such as the yeast concentration, processing temperature and isolation time on the isolation of GSH using Ultrasonic method. The disrupted cells solution was centrifuged at 12,000 rpm for 20 min and the GSH content in the supernatant was analyzed by taking the OD value of the solution using Spectrophotometer at 412 nm. To study the effect of yeast concentration, yeast solution with the concentration of 3, 6, 9 and 12 wt.% was disrupted at their original temperature for 15 sec. The result shows that the optimum value of yeast concentration is 6 wt.% where 12.93 μmol mL-1 GSH was isolated. To study the effect of processing temperature, Ultrasonic process of the 6 wt.% yeast solution was done at various values of temperature such as 19, 22, 25, 28, 30 and 40�C for 15 sec. The results indicated that, the optimum GSH isolation temperature is 22�C with the isolation of 13.53 μmol mL-1 GSH. Then, to study the effect of isolation time, the Ultrasonic process of sample with the concentration of 6 wt.% was done at 22�C for 15, 30, 45 and 60 sec. The result indicated that the optimum isolation time for the Ultrasonic process is 15 sec

Comparison studies among the methods used in isolating the GSH from baker yeast

The purpose of this study was to make a comparison among the methods used in isolating the GSH from baker yeast. This was done by comparing the optimum values of operating parameters such as the yeast concentration, processing temperature and the isolation time of each of the isolation methods used (Autolysis, Ultrasonic and Homogenizer). Among the three methods, Autolysis method produced the highest GSH concentration of 49.263 μmol mLG1 (15.14 g LG1) followed by Homogenizer method (18.33 μmol mLG1 or 5.63 g LG1) which is slightly higher than that of the Ultrasonic method (18.13 μmol m L G 1 or 5.57 g L G 1). The different occurred probably due to the different of the isolation time applied to the three methods. The same duration time couldn’t be used because it will increase the temperature of the sample higher that the optimum temperature of some of the methods. Unlike Ultrasonic and Homogenizer methods, the temperature for Autolysis method could be maintained within 1 h while for Homogenizer and Ultrasonic methods the temperature could only be maintained within 30 and 15 sec, respectively. The step down arrangement from best to worst for lab scale production was Autolysis>Homogenizer>Ultrasonic method. Autolysis was the best but the isolation time is longer compared to the other so that in large scale production, Homogenizer seems to be the best method due to the economical perspective. Ultrasonic is also can be considered as an excellent method but expensive compared to others

Comparison of alcohol free GSH production by ultrasonic and homogenizing method

Homogenizer and ultrasonicator that we call as mechanical methods were used in the lab scale production of alcohol free reduced glutathione (alcohol free GSH) from baker’s yeast. The study was done to determine the effects of specific parameters of the methods and the pH of the medium on the production of the GSH. The cell disruptions were run at a wide range of those parameters at the suitable common parameters of the methods. The disrupted cells suspension was then centrifuged at 12,000 rpm for 20 min and the GSH content in the supernatant was analyzed by taking the absorbance (A) value of the solution by spectrophotometer at 412 nm. The results obtained showed that the production of GSH was affected by the adjusted specific parameters of each method and the yield of production by the homogenizing and ultrasonic method was found 3.3 and 4.1 times, respectively, better than the yield of production by the unadjusted parameters. Ultrasonic method which produced 23.2 mg/L product was found 1.3 times better than the homogenizing method (18.5 mg/L) in producing the GSH. The result obtained from the lab scale study of the above mentioned mechanical methods showed that the implementation of them in the large scale production of the alcohol free GSH is possible