In most microalgal species, triacyglycerols (TAG) contain mostly saturated and monounsaturated fatty acids, rather than PUFA, while PUFA-enriched oil is the form most desirable for dietary intake. The ability of some species to produce LC-PUFA-enriched oil is currently of specific interest. In this work, we investigated the role of sodium bicarbonate availability on lipid accumulation and n-3 L...

In this article, polyphosphate-accumulating organisms (PAOs) from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron accept...

Experiments are conducted to determine the effect of a cage ofwatermolecules on the photolysis quantum yields of nitrate, FeOH2þ, and H2O2. Results suggest that the quantum yields of nitrate and FeOH2þ are decreased by the recombination of photo-fragments ( OH þ NO2 and Fe2þ þ OH, respectively) before they leave the surrounding cage of water molecules. However, no evidence is found for an enhan...

[1] In a yearlong investigation of the air-snow transfer function for nitrate (NO3 ) at the Greenland Environmental Observatory, Summit (3203 m above sea level), surface snow concentrations measured every other day were compared with levels measured in 10 snow pits dug adjacent to accumulation stakes. Concentrations in the surface snow ranged from 0.4 to 34 mM with a mean of 2.9 ± 1.9 mM. Measu...

The assimilatory nitrate reduction pathway is a vital biological process, as it is one of the principal routes by which inorganic nitrogen is incorporated into organic compounds in higher plants, algae, and fungi. After uptake into cells by nitrate transporters, the first and rate-limiting step in this pathway is the reduction of nitrate to nitrite catalyzed by NAD(P)H:nitrate reductase (NR), a...

Mutants of the pentose phosphate pathway have been isolated in Aspergillus nidulans. These fail to grow on a variety of carbohydrates that are catabolized through the pentose phosphate pathway. They also grow poorly on nitrate and nitrite as sole nitrogen sources. The pentose phosphate pathway mutations have been assigned to two unlinked genes. Mutants with lesions in the pppB locus have reduce...

The high affinity nitrate transport system in Arabidopsis thaliana involves one gene and potentially seven genes from the NRT1 and NRT2 family, respectively. Among them, NRT2.1, NRT2.2, NRT2.4 and NRT2.7 proteins have been shown to transport nitrate and are localized on the plasmalemma or the tonoplast membranes. NRT2.1, NRT2.2 and NRT2.4 play a role in nitrate uptake from soil solution by root...

To enhance our understanding of the genetic basis of nitrogen use efficiency in maize (Zea mays), we have developed a quantitative genetic approach by associating metabolic functions and agronomic traits to DNA markers. In this study, leaves of vegetative recombinant inbred lines of maize, already assessed for their agronomic performance, were analyzed for physiological traits such as nitrate c...

The onset and cessation of the synthesis of denitrification enzymes of Pseudomonas stutzeri were investigated by using continuous culture and defined dissolved oxygen levels covering the full range of transition from air saturation to complete anaerobiosis. Expression of nitrate reductase, nitrite reductase (cytochrome cd1), and N2O reductase was controlled by discrete oxygen levels and by the ...

* Author for correspondence: K.P. Chong, School of Sustainable Agriculture, Universiti Malaysia Sabah, 88999, Kota Kinabalu, Sabah, Malaysia, Tel: +6088-320000 Fax: +6088320278, [email protected]. Abstract. Rice blast disease, caused by Pyricularia oryzae Cav. is the most serious fungal disease in rice crop, and this disease has caused significant yield losses worldwide. Sakuranetin which is a...