Biochemical activity of auxins in dependence of their structures in Wolffia arrhiza [L.] Wimm.

Wolffia arrhiza (L.) Wimm. (Lemnaceae) as a mixotrophic plant reacts considerably weaker to used auxins with different chemical structures than typical photosynthetic vascular plants and algae especially from Chlorophyta. Among used auxin compounds, the highest stimulative activity on W. arrhiza growth and biochemical parameters which were analysed in biomass, can be attributed to phenylacetic acid (PAA), a somewhat smaller to indole-3-acetic acid (IAA) and the smallest to 2-naphthaleneacetic acid (NAA) used in optimal concentration of 10-6 M, in comparison with the control culture, devoid of exogenous auxins. The investigated auxins, especially PAA and IAA, were found to have the most powerful stimulative activity (prevailingly between the 10th and the 15th day of cultivation) on the content of reducing sugars between 127 and 169%, chlorophyll a and b from 117 to 125%, total carotenoids from 115 to 132% and net photosynthetic rate from 127 to 144% in comparison with the control culture, which was treated as 100% for reference. However, the content of water-soluble proteins as well as nucleic acids (DNA and RNA) in the biomass of W. arrhiza was less effectively stimulated, hardly from 110 to 116% when compared to the control culture (100%)

Comparison of stimulatory effect of cytokinins adenine and urea derivatives on the level of some components in Wolffia arrhiza [L.] Wimm. [Lemnaceae]

The effect of cytokinins with different chemical structures, adenine-type: N6-benzylaminopurine (BAP), N6-furfurylaminopurine (FAP) and derivative of urea - 1,3-diphenylurea (DPU) applied in optimal physiological concentrations of 10-6-10-4 M on the mixotrophic plant Wolffia arrhiza during the period of 20 days of culture, was examined. The cytokinin highest influence on the metabolites level in W. arrhiza fresh weight was demonstrated in the range of concentrations 10-6-10-5 M between the 5th and the 10th day of culture. Among used cytokinins, the highest stimulative effect on the content of water-soluble proteins can be attributed to DPU (181%), slightly lower to BAP (167%) and the lowest to FAP (113%) in comparison with the control culture (100%). BAP was found to exert the most stimulative activity on nucleic acids accumulation (DNA+RNA) to the maximum value (127%). FAP and DPU possessed weaker stimulative activity increasing the nucleic acid content to the level of 120% and 118%, properly. The content of monosaccharides was stimulated to the highest level of 174% in FAP treated plants, to 151% in case of BAP and in case of DPU to 144%. Whereas, the highest increase of the photosynthetic pigments content (chlorophyll a and b as well as total carotenoids) to the range of 123-146% in W. arrhiza culture in the presence of DPU, was observed. Under the influence of FAP the accumulation of photosynthetic pigments was stimulated less effectively to the range of 113-140%. When the plants grew with BAP the chlorophylls and carotenoids contents increased to the lowest values of 119-131%. On the other hand, the content of total carotenoids was stimulated only during the first days of culture, then between the 15th and the 20th day it was inhibited by all applied adenine and urea-type cytokinins to the value of 70%. The results indicate that there is no quantitative correlation between the structure of all analysed cytokinins and their influence on the biochemical responses of W. arrhiza

Biochemical activity of di- and polyamines in the green alga Chlorella vulgaris Beijerinck [Chlorophyceae]

This study concerns on the influence of diamines (agmatine, putrescine) and polyamines (spermine, spermidine) upon the growth and the content of chlorophyll a and b, monosaccharides and proteins in the cells of alga Chlorella vulgaris Beijerinck (Chlorophyceae). In the experiments agmatine, putrescine, spermine and spermidine in the range of concentrations 10-6-10-3 M were used. At the concentration 10-3 M and the 1st day of cultivation, they have a toxic effect on growth of the algae. It was found that di- and polyamines used within the range of concentration 10-6-10-4 M stimulate the growth and the contents of analysed biochemical parameters in the cells of C. vulgaris. The most stimulating influence on metabolism of the alga was demonstrated by spermidine and putrescine at concentration of 10-4 M. Agmatine and spermine were characterised by a lower biological activity than spermidine and putrescine demonstrated the most stimulating influence

Effect of microencapsulation on concentration of isoflavones during simulated in vitro digestion of isotonic drink

Isotonic drinks, fortified with microencapsulated maltodextrin and inulin isoflavone extract, were evaluated by organoleptic assessment and color measurement on the CIE L*a*b scale, then they were subjected to in vitro digestion. Changes of concentrations of isoflavones released during digestion of drinks and their ability to neutralize free radicals (ABTS) were determined. The effect of microencapsulation and storage on isoflavone content in isotonic drinks was also evaluated. In the organoleptic evaluation, beverages without additives and beverages fortified with microencapsulated extract were evaluated as better than a beverage with pure extract. Microencapsulation largely eliminated the unpleasant taste and odor of isoflavones and masked their color. Before digestion, isotonic drinks contained 29.07–43.17 μg of isoflavones in 1 ml. Microencapsulated isoflavones were released gradually during simulated digestion. The highest recovery of these compounds was observed for glycoside and malonylate derivatives of daidzein. Daidzin and genistin with encapsulation showed bioavailability of 0.02%–0.07%. The use of inulin as a carrier increased the stability of microcapsules during the storage of isotonic beverages. Microencapsulated of isoflavones from soybeans can increase the health benefits of conventional beverages available on the market