[Fluorescence, excited by light in the 380-540 nm wavelength range, in in cucumber leaves depends on the time of vegetation and light regime]. / Fluorestsentsiia, vozbuzhdaemaia svetom v diapazone dlin voln 380-450 nm, v list'iakh ogurtsa v zavisimosti ot vremeni vegetatsii i svetovogo rezhima.

The slow fluorescence induction produced in cucumber leaves by light in the range of wavelengths 380-540 nm and intensity of 180 W/m2 was studied. The ratio of fluorescence maxima in the red region (F734/F682) in young and mature leaves was approximately 2. It is assumed that this value depends on an increase in the contribution of the long-wavelength fluorescence due to the spillover effect. In plants grown under natural conditions, the parameter F734/F682 correlated with the concentrations of chlorophyll and carotenoids. In plants grown in the light of red and blue regions no such correlation was observed and the F734/F682 remained unchanged. It is concluded that the F534/F682 is affected by the intensity and spectral composition of exciting light used during the growing.

[Continuous cultivation of Photobacterium phosphoreum luminescent bacteria with control of the luminescence]. / Nepreryvnoe kul'tivirovanie svetiashchikhsia bakterii Photobacterium phosphoreum s upravleniem po liuminestsentsii.

The paper describes a procedure for continuous cultivation of luminescent bacteria Photobacterium phosphoreum according to which the nutrient flow is controlled with respect to the luminescence intensity. The biomass yield of this cultivation procedure at the given luminescence intensity 6.1 X 10(12) quantum X ml-1 s-1 is over three times higher than that obtained in periodic cultivation, with the specific cell luminescence being identical in both cases. The cultivation process is unstable at the luminescence intensity 4.1 X 10(12) quantum X ml-1 s-1 and the glycerol content in the nutrient medium over 6 g/l. Practical applications of the above procedure for the cultivation of luminescent bacteria are discussed.

[NADPH- and ATP-dependent luminescence of extracts from luminous bacteria]. / Zavisimaia ot NADPH i ATP liuminestsentsiia ékstraktov svetiashchikhsia bakterii.

It was shown that the luminescence of extracts prepared from luminous bacteria is stimulated by NADPH and ATP without FMN or long-chain aliphatic aldehydes, which are routinely used for producing luminescence of extracts from luminous bacteria in vitro. In these extracts an aldehyde factor, a natural analog of aliphatic aldehydes, is synthesized. The enzymatic system involved in maintaining the luminescence of NADPH and ATP is probably not coupled with the functioning of NAD(P)H: FMN oxidoreductase which has been supposed to participate in luminescence processes in vivo. It is assumed that both aldehyde factor synthesis and reduction of endogenous analog of FMN, natural substrates of bacterial luciferase, are due to the functioning of the same metabolic pathway.

[Effect of phenobarbital on the luminescence system of luminous bacteria]. / Vliianie fenobarbitala na liuminestsentnuiu sistemu svetiashchikhsia bakterii.

The effect of phenobarbital on the luminescent system of Beneckea harveyi was studied. The inhibition of luminescence with phenobarbital was shown to be due to a disorder in the synthesis of an aldehyde factor, the endogenous substrate of bacterial luciferase. Upon the action of phenobarbital, the bacterium acquires the properties of "aldehyde" mutants, i. e. their luminescence is stimulated with exogenous decyl aldehyde. The luminescence of the cells was also stimulated with long-chain aldehydes, fatty acids and their analogues: apparently, the aldehyde factor is formed via incorporation of an oxygen atom into the terminal methyl of a saturated fatty acid or its analogue. Phenobarbital has no effect on the bacterial growth; however, it increases the content of luciferase in the culture. The results suggest that phenobarbital is not a direct inductor of luciferase synthesis. Possibly, the stimulating action of phenobarbital involves the inhibition of synthesis of the aldehyde factor and, consequently, an increase in the concentration of intermediate products of its synthesis.

[Luciferase synthesis regulation in Photobacterium mandapamensis]. / Reguliatsiia sinteza liutsiferazy u Photobacterium mandapamensis.

The synthesis of luciferase and the dynamics of luminescence were studied in the course of batch cultivation of the strain 54-K obtained from the wild strain of Photobacterium mandapamensis after numerous passages. Luciferase synthesis bvy the strain was not sensitive to the inhibitor contained in the growth medium and did not require the accumulation of an "audoinductor". Since the intensity of luminescence and the content of luciferase per cell did change, the bacterium seemed to possess an additional system for regulating the synthesis of luciferase which was independent of the "autoinductor" and the inhibitor.