ETHANOL PRECIPITATION OF GLYCOSYL HYDROLASES PRODUCED BY Trichoderma harzianum P49P11

Abstract

-This study aimed to concentrate glycosyl hydrolases produced by Trichoderma harzianum P49P11 by ethanol precipitation. The variables tested besides ethanol concentration were temperature and pH. The precipitation with 90% (v/v) ethanol at pH 5.0 recovered more than 98% of the xylanase activity, regardless of the temperature (5.0, 15.0, or 25.0 °C). The maximum recovery of cellulase activity as FPase was 77% by precipitation carried out at this same pH and ethanol concentration but at 5.0 °C. Therefore, ethanol precipitation can be considered to be an efficient technique for xylanase concentration and, to a certain extent, also for the cellulase complex.

Extraction, precipitation and characterization of urease from Vicia faba L.

“…The precipitate had been collected; centrifuged and dissolved in 5ml phosphate buffer 0.05M. The extract was centrifuged for 5 min and the activity of clear suspension would be determined [11]  Alcohol precipitation Two milliliter of crude extract was added to 2ml of ethanol 60% and left for 6 hours, the precipitation solution was separated by centrifuge 3000 r/min for 10 minutes, then it was dissolved in 0.05 M of sodium acetate buffer pH 5 and the enzyme activity was determined [12]  Ammonium sulfate precipitation The crude extract of broad beans was isolated and saturated using ammonium sulfate in order to estimate urease precipitation in a ratio ranged between 20-80%, the protein molecules would be precipitated in a solution, the precipitate was washed against 0.02 M of phosphate buffer [13] According to method described in [13] with slight modification, ureases enzymes activities were estimated .The precipitated enzyme and the reaction mixture consisted of 0.02M urea; 0.002 M CaCl 2 and 0.1 M of Tris-Hcl pH 8.0 were mixed in a ratio 1:1 (v/v) then incubated for 30 minutes at 30°C, then the reaction was stopped using 0.5 ml of H 2 SO 4 (1 N). Urease activity was estimated by determining the amount of ammonia resulted from urea hydrolysis.…”

Techno-economic analysis of the industrial production of a low-cost enzyme using E. coli: the case of recombinant β-glucosidase

“…We have previously evaluated the potential of glycosyl hydrolase precipitation using ethanol under different temperature and pH conditions. In our experience, β-glucosidase activity can be almost fully recovered using 90% (v/v) ethanol at 25 °C and pH 6.5, indicating the potential of this solvent for use in a 2G ethanol plant [ 36 ].…”

Ethanol Precipitation as a Downstream Processing Step for Concentration of Xylanases Produced by Submerged and Solid-State Fermentation

“…Ethanol is one of the most important industrial precipitants, and its use can lead to a favorable balance between the solubility effect and an appropriate hydrophilicity, minimizing protein denaturation (Golunski et al, 2011). However, in order to achieve high precipitation recovery of xylanase activity, a relatively high ethanol concentration (≥80%, v/v) is usually required (Fadel, 2001;Marino et al, 2015;Varma et al, 1999). This increases cost as well as the risk of protein denaturation, hence compromising the feasibility of the DSP.…”

“…Overall, the results achieved here for xylanase precipitation with ethanol were very satisfactory, when compared to the literature (Table 5), indicating that the procedure can be considered as a potential DSP unit operation for the concentration of A. niger xylanases from different cultivation systems. (Marino et al, 2015) Chainia sp. 66% ethanol overnight 78.5 13.70 (Varma et al, 1999) 80% ethanol 99.0 15.97 Table 5.…”