We investigate some properties of nonlinear integral operators of Urysohn--Stieltjes type with kernels depending on two variables.
Results concerning the continuity and compactness of these operators are obtained. The solvability of nonlinear Urysohn--Stieltjes
integral equations is also studied.
Authors:M. Zych, A. Stolarczyk, K. Maca, A. Banaś, K. Termińska-Pabis, A. Kapuścik, S. Klasik and J. Burczyk
Differences in the assimilation of individual organic compounds (5 mM sugars and L-asparagine) under mixotrophic growth conditions were described for three naturally occurring
strains.The effects of assimilation were measured by the growth intensity and size of algal cells, and the effect of colour changes in the cultures was observed. Some compounds caused the cell colouration to change from green to yellow, being the result of chlorophyll disappearance and the accumulation of yellow secondary carotenoids. In the present experiment none of the cultures turned red, thus excluding the intense accumulation of the commercially interesting carotenoid, astaxanthin.
Authors:M. Zych, J. Burczyk, M. Kotowska, A. Kapuścik, A. Banaś, A. Stolarczyk, K. Termińska-Pabis, S. Dudek and S. Klasik
Algal strains belonging to the
show significant differences in the extent of staining with the commonly used dye, crystalline violet. This seems to depend on the cell wall composition and on the occurrence of the acetolysis-resistant biopolymer algaenan in the algal cells.Eighteen algal strains were investigated using 24 h staining with 0.2% crystalline violet and it was confirmed that algal strains which did not contain algaenan and had a trilaminar structure in the cell wall showed strong staining ability, while non-algaenan strains were stained very weakly, if at all. The simple method presented here may be helpful to distinguish both kinds of algal strains.