BACKGROUND Nitrogen starvation and limitation are known to induce important physiological changes especially in lipid metabolism of microalgae (triglycerides, membrane lipids, beta-carotene, etc.). Although little information is available for Dunaliella salina, it is a promising microalga for biofuel production and biotechnological applications due to its ability to accumulate lipid together wi...

Two laboratory-scale sequencing batch reactors were used to study biological treatment of carbon and nitrogen in a new combined anaerobic-aerobic system. Piggery wastewater was used as a model effluent. The anaerobic reactor, fed with raw wastewater and nitrite/nitrate recycling from the aerobic reactor, carried out denitrification and anaerobic digestion of organic carbon. In the aerobic react...

A physiological, unbalanced model is presented that explicitly describes growth of the marine cyanobacterium Trichodesmium sp. at the expense of N(2) (diazotrophy). The model involves the dynamics of intracellular reserves of carbon and nitrogen and allows the uncoupling of the metabolism of these elements. The results show the transient dynamics of N(2) fixation when combined nitrogen (NO(3)(-...

in temperate forests canopy gaps play an important role in driving stand dynamics. the purpose of this research was to compare soil characteristics in forest gaps with several size and its relation to beech regeneration density in lalis forest, chalous. in order to investigate factors, three gap sizes as small gap (200 m2), medium gap (400 m2), and large gap (600 m2) with three replicate were s...

Background: As the decomposition of lignocellulosic compounds is a rate-limiting stage in the nutrient mineralization from organic matters, elucidation of the changes in soil enzyme activity can provide insight into the nutrient dynamics and ecosystem functioning. The current study aimed to assess the effect of thinning intensities on soil conditions. Un-thinned control, 20 % thinning, and 30 %...

The types of carbon source and nitrogen source used as well as the C:N ratio in the medium influenced lovastatin production by Pleurotus ostreatus. The maximum value of the lovastatin yield was obtained in a medium that contained organic nitrogen.

The aim of the experiment was to analyze the particular processes (biomass synthesis, oxidation, denitrification and accumulation) during carbon removal from wastewater. The experiment was carried out in a sequencing batch reactor (SBR) in two series with different organic carbon compounds to nitrogen compounds ratio (COD/N). Organic carbon loading of activated sludge was 0.07 g COD/g·d. Organi...