Diffuse reflectance infrared Fourier transform (DRIFT) and Mössbauer spectroscopic study of Azospirillum brasilense Sp7: Evidence for intracellular iron(II) oxidation in bacterial biomass upon lyophilisation.

Microbial cells are well known to be capable of remaining viable when desiccated, and a variety of beneficial microorganisms can thus be preserved for storage. For the ubiquitous widely studied soil bacterium Azospirillum brasilense (wild-type strain Sp7), which has a significant agrobiotechnological potential owing to its plant-growth-promoting capabilities perspective for its use in biofertilisers, Fourier transform infrared (FTIR) spectroscopy (in the diffuse reflectance mode, DRIFT) was used to control the state of biomass, together with Fe transmission Mössbauer spectroscopy to monitor intracellular iron speciation in live rapidly frozen cell suspension and in the lyophilised biomass (both measured at T = 80 K). It has been shown for the first time that a relatively large part of ferrous iron in live cells (22% of the whole cellular iron pool, represented by two high-spin Fe(II) forms, in the 18-h culture grown on Fe(III) complex with nitrilotriacetic acid as the sole source of iron) gets largely oxidised upon lyophilisation.

[The regional indicators of male fertility in the Samara oblast and causative factors of their alterations].

The apparent tendency of decreasing male fertility is observed during last years. Basically, this occurrence is related to deterioration of environment conditions, harmful habits and male's organism state. The WHO standards of indicators of spermogram were formulated by averaging the statistical data collected in various countries.