I need to know, if the temperature around 60°C-70°C can efficiently kill the enzymes that involve in non-structural carbohydrate cleavage.
In one experiment we´ve boiled root samples in 50% ethanol for at least 15 min at 80°C and we´re sure that the enzymes were killed as we compared the results with liquid nitrogen and subsequent lyophilization procedure and it was comparable. We´ve also tried a procedure where it was only put into 50% ethanol in ambient temperature without boiling and only the total sum of carbohydrates was comparable with that of liquid nitrogen treatment and the ratio of free sugars to polysaccharides was different, so it implies that the enzymes were not killed immediately.
What will happen if we boil it in 50% ethanol, but the temperature is lower – 60/70°C? Is the standard 80°C :
1) the lowest possible for the enzyme denaturing?
2) kind of „excessive“ just to be sure that the enzymes are killed and also the best for the extraction of carbohydrates (the highest yield)?
Does ethanol by itself stop the enzymes?
I´ve searched in the literature and for the temperature 60-70°C, I´ve found only air-drying treatments which are not efficient for the enzyme stopping. And in case of putting the samples into liquid solutes, I´ve found temperatures >80°C. Most of the studies used pure water or 80% ethanol instead of 50 % as a medium.
I´ve found 1 paper where they discuss the lethal temperature for woody tissue in case of fire and it was 60°C. But they mentioned that the mitochondries are killed, I´m not sure if also the carbohydrate splitting enzymes are stopped (fructanases, sucrase, amylase, α-galactosidase etc.). When I searched for the information about individual enzymes in vivo, I found only treatments with t>80°C. And in case of commercial enzymes I found that these enzymes work the best around 40-60°C and then the activity decreases (which does not mean that they´re killed, I assume) and that they become unstable. But most of these commercial enzymes were of microbial or fungal origin.
Does anybody have an idea? Or is it necessary to try it experimentally...
Thank you!
Kindly check https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.13955
Also check https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5468369/
Amylase from many plants is stable to boiling. I don't think it survives autoclaving but I haven't checked.
Ann G Matthysse Thank you, yes, commercially available amylases are thermo-stable at 100°C, but I have to check if also the amylase in plants is. Zuzana
- Badges
- Science topic
- Similar topics
- Biological Science
- Biota
- Eukaryota
- Viridiplantae
- Streptophyta
- Plants