[Pigmentation of Serratia marcescens and spectral properties of prodigiosin].

Pigmentation of Serratia marcescens depends on the composition of the cultivation medium. The cultures grown on glycerol-peptone medium and on the medium with acetate are red and yellow (yellowish orange), respectively, with the color depending on the ambient pH. S. marcescens cells growth on glycerol-peptone medium (visually of red color) contain two forms of prodigiosin: the "red" and "yellow" ones with absorption maxima at 535 and 460-470 nm, respectively. The absorption spectrum of prodigiosin in the native pigment-protein complex was different from the spectrum of the pigment dissolved in ethanol and resembled that of the cell suspension in the presence of an additional absorption maximum at 500 nm.

[Calcium as a control factor of nitrogenase activity in Vicia faba L. root nodules: calcium release from symbiosomes and the accompanying decrease in their nitrogenase activity is blocked by verapamil]. / Kal'tsii v kontrole nitrogenasnoi aktivnosti kornevykh kluben'kov Vicia faba L.: vykhod kal'tsiia iz simbiosom i soputstvuiushchee emu snizhenie ikh nitrogenaznoi aktivnosti blokiruiutsia verapamilom.

Treatment of root nodules or symbiosomes isolated from them with calcium chelator EGTA alone or with calcium ionophore A23187 for 3 h under microaerophilic conditions considerably decreased their nitrogenase activity (NA). Under these experimental conditions, cytochemical electron microscopy demonstrates a considerable calcium depletion in symbiosomes of the infected nodule cells by EGTA and A23187. Ca2+ channel blockers, verapamil and ruthenium red, inhibited EGTA-induced Ca2+ release from symbiosomes. In this case, NA insignificantly increased in the whole nodules and reached the baseline in symbiosomes. The experiments on isolated symbiosomes and arsenazo III demonstrated that verapamil inhibited Ca2+ transport induced by valinomycin at the background of K+ ions. These data suggest the presence of a verapamil-sensitive transporter on the peribacteroid membrane responsible for Ca2+ release from symbiosomes. A possible role of this transporter in the interaction between symbiotic partners in the infected cells of the root nodules is discussed.

[The effect of the cultivation conditions on the growth and pigmentation of Serratia marcescens]. / Vliianie uslovii kul'tivirovaniia na rost i pimentatsiiu Serratia marcescens.

The influence of cultivation conditions on the growth and pigmentation of S. marcescens was studied. The cultures under study grew in media containing glycerin, glucose or acetate and organic or mineral nitrogen. Pigment formation occurred in a medium with organic nitrogen and glycerin or acetate, but not glucose. Sodium chloride inhibited the growth of cultures, but at a concentration not exceeding 4-5% increased the accumulation of prodigiosin. Prodigiosin was accumulation by the culture growing at 28 degrees C, while at 37 degrees C no accumulation of the pigment occurred. The illumination of the growing culture with visible light decreased the intensity of its pigmentation. Prodigiosin apparently plays an important role in the metabolism of S. marcescens and is linked with the energy exchange of the cell.

Effect of various growth conditions on pigmentation of Serratia marcescens.

Prodigiosin biosynthesis in Serratia marcescens depends on growth conditions. In the presence of various concentrations of NaCl, pigment synthesis started later, but up to 4-5% NaCl increased prodigiosin accumulation per biomass unit. Visible light (< 2,000 lux) influenced pigmentation without changing the growth characteristics of the culture. The maximum prodigiosin content in dark and light cultures was observed on days 3-4 and 2-3, respectively. The influence of illumination conditions on pigmentation of S. marcescens was demonstrated. Light directly affects the pigment itself which is synthesized by the culture. Growing cells contain mono and dimer forms of prodigiosin in glycerol, with light influencing these pigments.

[Specificity of the action of the RNA released by Ehrlich carcinoma cells on the transplantability and growth of a homologous tumor]. / Spetsifichnost' deistviia RNK, vydeliaemoi kletkami kartsinomy Erlikha, na privivaemost' i rost gomologichnoi opukholi.

A comparative study was undertaken on the effect of different RNA preparations on the transplatability and growth of Ehrlich carcinoma. The RNA isolated from Ehrlich carcinoma ascites fluid was found to render the specific stimulating action on the transplantability and growth of a homologous tumor, while total RNA from bovine liver, tRNA from rabbit liver and synthetic polyribonucleotides show no stimulating effect. The RNA from Ehrlich carcinoma ascites fluid is formed as a result of its release from intact tumor cells, and it seems to be one of the factors responsible for the interaction between the tumor and the organism.

Biochemical and cytological studies of mitochondrial development in chloramphenicol-induced rice coleoptiles.

The ultrastructure and respiratory activity of mitochondria in rice coleoptile grown in the presence and in the absence of an inibitor of mitochondrial protein synthesis (chloramphenicol) have been studied. It is shown that during the first 48 h of germination a rapid development of mitochondrial cristae takes place without notable influence of chloramphenicol on biogenesis of mitochondria. But the presence of the inhibitor has a significant effect in the subsequent period (48-144 h): a gradual and almost complete reduction of mitochondrial cristae is observed. These unusual "noncristate" mitochondria, although greatly lacking cytochrome oxidase, have a high respiratory activity. The respiration of "noncristate" mitochondria is resistant to KCN. It is supposed that chloramphenicol-induced rice coleoptile can be used as a new convenient object for studies of the nature of alternative oxidase as well as the biogenesis of mitochondria with cyanide-insensitive respiration.