Journal of Bioprocessing & Biotechniques

Polyvalent antivenom IgG s produced in equines against different snake venom are used for treatment in snakebite cases. For this, hyperimmune equine plasma is fractionated and purified before use. Hence, serum related side effects are common. To reduce it, search for more effective method with high yield and purity, is of concern. In the present study, a modified caprylic acid method for the fractionation of IgG, has been described. The method was also compared with routine method and previously described caprylic acid methods. The results indicated that modified caprylic acid method at concentration 1.5%, pH 4.8 with stirring for 60 minutes, was superior in terms of yield, and purity as compared to other methods (p<0.05). The purified lgG were also found to have better neutralizing potency against all the four venoms viz., Cobra (Naja naja), Krait (Bungarus caeruleus), Russell’s viper (Vipra russelli), and Saw Scaled viper (Echis carinatus). The results suggest that modified caprylic acid method, could be of great value for commercial scale production of antivenom with respect to its efficacy, simplicity, low cost, reduced production time and above all high yield of colorless lgG finished product.

In the present study, we optimized the parameters for maximum yield of xylitol and ethanol by Candida tropicalis strain LY15 utilizing different Hemicellulosic Waste substrates (HWs) obtained by Acid-Alkaline hydrolysis method. Using the pomegranate peel as substrate, higher yield of xylose reductase, xylitol and ethanol were obtained. The optimal level of variables such as inoculum, HWs concentration, time period and RPM (agitation speed) were determined by the response surface methodology, with a significant co-efficient determination of R²= 0.89. Positive correlation was obtained with our experimental and predicted values. The interactions with the ideal levels of inoculum (1%), HWs (Pomegranate peel) (2%), time period (60 h) and RPM (140) showed highly significance values of xylose reductase (171.5 IU/mL), xylitol (55.57 g l^-1) and ethanol (3.37 g l^-1) at an incubation period of 60 h. The dual yield produced by Candida tropicalis strain LY15 using pomegranate peel makes the organism potent candidate for industrial application.

The knowledge of sedimentation kinetics is a necessary requisite for an adequate design of settlers aiming the separation and recovery of yeasts in alcoholic fermentation processes. In this study, batch and continuous settling tests were performed using slurries of flocculating yeasts obtained from the fermentation of sugarcane juice in a tower reactor with cell recycling. The batch tests were conducted in a 250 mL cylindrical glass vessel with initial concentrations of yeast between 90 and 100 g/L by measuring the variation over time of the height of the interface between the clarified liquid and the thickened slurry. These data were conveniently converted into cell concentration of the thickened sludge and a semi-empirical equation was developed to estimate the kinetic parameters of the settling. Data taken in a continuous settler in two continuous fermentation systems of different scales with cell recycle were also well fitted by the semi-empirical equation, but the adjusted parameters were different from those obtained for the batch tests.