[Comparative study of the pullulans synthesized by Pollularia (Aureobasidium) pullulans strains of different ploidies]. / Sravnitel'noe izuchenie pullulanov, sinteziruemykh shtammami Pullularia (Aureobasidium) pullulans raznogo urovnia ploidnosti.

Pullularia pullulans strains of different ploidy synthesize pullulans similar in their characteristics to those described in literature. These are glucans whose glucose residues are linked with alpha(1 leads to 4) and alpha(1 leads to 6) bonds in the proportion of 2.2:1. The pullulans differ from one another in their water solubility, molecular mass and in the ability to be cleaved by alpha-amylase and dextranase. The minor structural modifications of pullulan molecules in the polyploid strains as compared to the pullulan synthesized by the parent haploid culture are caused, apparently, by mutations induced with mitotic poisons.

[Effect of carbon and nitrogen sources on pullulan biosynthesis by polyploid strains of Pullularia pullulans]. / Vliianie istochnikov ugleroda i azota na biosintez pullulana poliploidnymi shtammami Pullularia pullulans.

The effect of eight carbohydrates and three nitrogen sources on the activity of pullulan accumulation was studied with a haploid strain, a diploid strain and a tetraploid strain of Pullularia pullulans. The rate of pullulan biosynthesis was found to be the highest in media containing glucose, sucrose and maltose. In this case, the activity of the polysaccharide synthesis in the polyploid strains exceeded that in the haploid strain by 21-80% depending on the carbon source in the medium. The pullulan synthesizing activity of the tetraploid strain depended on the nature of these carbohydrates to a lesser extent than in the case of the haploid and diploid strains. The activity of pullulan synthesis was influenced noticeably by the source of nitrogen in the medium. The greatest amounts of pullulan were accumulated by the three strains in a medium with sodium nitrate.