wild type strain the shapes of most of the cells of strain y 50799 grown on galacturonic acid are round with dimples which are notably different from the urn shaped cells with bud like projections observed in the micrograph for the wild type strain variable nucleotide tandem repeat vntr pcr analysis was performed to detect differences in genomic dna sequences using as pcr primer the 15 base pair bp 5 u00d7 cag repeat sequence genomic dna from wild type k marxianus nrrl y 1109 and mutant strains y 50798 or y 50799 was isolated from a 1 ml sample of a 2 day 37 u00b0 c culture in ypd liquid medium in a 1 5 ml polypropylene tube the samples were vortexed for 30 seconds and then centrifuged at 15 800 u00d7 g for 2 minutes thermo micromax microcentrifuge thermo fisher scientific waltham mass usa the supernatant was decanted and an additional 1 ml of the culture was added to the tubes the tubes were vortexed for 30 seconds and then centrifuged at 15 800 u00d7 g for 2 minutes the supernatant was decanted and 400 u03bcl of water were added the mixture was boiled for 10 minutes followed by addition of 400 u03bcl of phenol solution saturated ph 6 6 amresco llc solon ohio usa the tubes were vortexed for 30 seconds and then centrifuged at 15 800 u00d7 g for 2 minutes the aqueous phase was transferred by pipet to new 1 5 ml tubes and 400 u03bcl of phenol chloroform isoamyl alcohol 25 24 1 tris.