Structural and functional changes in photosynthetic apparatus of wheat under exposure to sulfur dioxide fumes.

Changes in photosynthesis of wheat (pigment content and chlorophyll fluorescence) have been measured to study effect of gaseous sulfur dioxide on wheat cenosis. Several biochemical and biophysical techniques have been estimated to evaluate their ability for early detection of destructive effect of SO2. A mathematical model of toxic gas absorption in a closed system with plants has been proposed.

Interaction of physical-chemical and biological regeneration processes in ecological Life Support Systems.

Catalytic combustion of inedible biomass of plants in ecological Life Support Systems (LSS) gives rise to gaseous oxides (CO2, NO2, SO2, etc.). Some of them are toxic for plants suppressing their photosynthesis and productivity.

Impaired growth of plants cultivated in a closed system: possible reasons.

Plants in experiments on "man-higher plants" closed ecosystem (CES) have been demonstrated to have inhibited growth and reduced productivity due to three basic factors: prolonged usage of a permanent nutrient solution introduction into the nutrient medium of intra-system gray water, and closure of the system. Gray water was detrimental to plants the longer the nutrient solution was used. However, higher plant growth was mostly affected by the gaseous composition of the CES atmosphere, through accumulation of volatile substances.

Waste bioregeneration in life support CES: development of soil organic substrate.

An experimental model of matter turnover in the biotic cycle: plants (plant biomass) --> mushrooms (residual substrate + mushroom fruit bodies) --> worms (biohumus) --> microorganisms (soillike substrate) --> plants is presented. The initial mass of soillike substrate was produced from wheat plants grown in a hydroponic system. Three cycles of matter turnover in the biotic cycle were carried out.

Cultivation of plants in space: their contribution to stabilizing atmospheric composition in closed ecological systems.

Higher plants in biological life support systems (BLSS) not only supply man with food, accomplish recirculation of major gases (CO2 and O2) and reclaim water, they also help remove toxic impurities produced by the ecological system components from the atmosphere of the system. Experiments to study the effect of SO2 on mixed canopies of agricultural plants with pulsing and continuous supply of gas into a sealed volume of the ecosystem showed that gaseous toxic substances can be a) passively absorbed by biologically inactive components of the system, b) actively absorbed and processed by plants. Passive absorption can be described by kinetics with saturation, active absorption--by enzymatic kinetics equations.