mnick12 - 9-11-2014 at 11:15
Does anyone know where to buy Maltotriose or amylose? Sigma is waaaay to expensive.
Apparently there are knockout versions of maize and potatoes whose starch contains something like 98% amylose, but I can't seem to find a source.
Ideally I am looking for somewhere around 250-500g of Maltotriose and a similar amount of amylose.
Thanks.
Ozone - 10-11-2014 at 05:15
Discrete oligosaccharides and purified amylose are expensive because they need to be tediously isolated via chromatography and/or fractional
precipitation.
If you have the equipment, maltotriose is readily isolated from commercial High-malt products such as "Satin Sweet" which contain between 16-20% (on
dry solids, the material is either solid or a syrup at about 82% RDS) maltotriose (the bulk of the rest is about 65% maltose, glucose (5%) and higher
oligomers). Strong acid cation resin (chromatographic grade, 200-200 um) in the H+ form eluted with water will do it.
As for amylose, the solubility in water is less than for the corresponding amylopectin, so it can be purified (at least in the bulk sense) via
fractional ppt with EtOH.
Interestingly, pure amylose is emerald green with iodine.
Cheers,
O3
mnick12 - 26-11-2014 at 23:23
Thanks Ozone,
My intetion for maltotriose is to develop a medium for the isolation of attenuative wild yeasts, specifically yeasts for brewing. It looks like I will
have to find some other way. I have done the digestion of gelatinized potato starch with alpha amylase, but I have not idea what the composisiton of
the material is.
Little_Ghost_again - 28-11-2014 at 03:19
Have a look here
https://eurekabrewing.wordpress.com/2012/08/24/yeast-banking...
There is no need to spend huge sums for plating up yeast, agar agar and dextrose or malt extract is often enough, makr sure your aseptic technique is
good though. It takes alot of practice to do it right, watch some vids on how to streak out so you get a single colony at the end of a streak. Dont
push/pull too hard, stroke the agar with the loop or pick, for this kind of thing I would use a broth for 48 hours (yeast extract and maybe very small
amount fructose) then a loop to plate say 4 plates, incubate 72 hours and from there use a pick to streak and plate 4 new plates of any useful looking
colonies. If you have a microscope go for the haploid cells, the diploid ones will throw all kinds up.