(Table 1) Main parameters of consumption of inorganic nitrogen compounds by microplankton in the western Black Sea in April 1993

Parameters of provision of the phytoplankton community with inorganic nitrogen compounds in the western Black Sea in April 1993 are analyzed (specifically, dependence of rates of uptake of nitrates and ammonium by microplankton on substrate concentration, diurnal dynamics of assimilation of mineral nitrogen, values of f-ratios, and proportions of carbon and nitrogen fluxes). In most cases all the parameters of degree of phytoplankton provision with mineral nitrogen are shown to vary unidirectionally, both at the surface and in the photosynthesis zone. Individual areas of a relatively small region studied differed markedly in their level of provision of algae with inorganic nitrogen compounds - from complete saturation to high degree of limitation of phytoplankton development due to nitrogen deficiency in the environment. Obtained results allow to estimate provision of Black Sea phytoplankton with nitrogen in terms of limitation of rates of uptake of its inorganic compounds.

Concentration profiles in batch fermentation of hydrolyzed lignocellulose

Experimental data was obtained for profiling changes in concentrations of two inhibiting compounds in batch fermentation of a synthesized liquor resembling hydrolyzed lignocellulose, a furan (furfural) and a phenolic compound (vanillin), along with standard fermentation data, i.e. substrate, biomass and ethanol concentrations. The initial inhibitor concentrations and fermentation temperatures in the 18 experiments were varied according to a two-level complete center composite experimental design. Based upon these observed variations in the fermentative behavior, the fermentation kinetics were modeled, as published in the corresponding article, including microbial conversion rates of the inhibitive compounds into their less toxic derivatives.