Phosphate limitation

Guasch H, Navarro E, Serra A, Sabater S (2004) Phosphate limitation influences the sensitivity to copper in periphytic algae. Freshw Biol 49 463... 

Typically, functional porins are homotrimers, which assemble from monomers and then integrate into the outer membrane. The general porins, water-filled diffusion pores, allow the passage of hydrophilic molecules up to a size of approximately 600 Daltons. They do not show particular substrate specificity, but display some selectivity for either anions or cations, and some discrimination with respect to the size of the solutes. The first published crystal structure of a bacterial porin was that of R. capsulatus [48]. Together with the atomic structures of two proteins from E. coli, the phosphate limitation-induced anion-selective PhoE porin and the osmotically regulated cation-selective OmpF porin, a common scheme was found [49]. Each monomer consists of 16 (3-strands spanning the outer membrane and forming a barrel-like structure. 

Clostridium acetobutylicum Escherichia [Fe] hydrogenase [NiFe] Putative cytoplasmic, ferredoxin linked H2 production during fermentation Fermentation pathway, phosphate limitation 4... 

Escherichia coli [NiFe] hydrogenase 3 Membrane-associated component of the formate hydrogen lyase complex H2 production during fermentation H2 uptake under anaerobic conditions Anaerobiosis, carbon source limitation, phosphate limitation, molybdenum, nitrate, formate 7.8... 

Vanadate is taken up by N. crassa when the cells are phosphate limited and growing in higher pH values. It takes place by the phosphate transport system II, which has high affinity for phosphate. Phosphate is a competitive inhibitor of vanadate uptake.1071 This confirms the competitive relationship between phosphate and vanadate. 

To perform the complete set of chemical analyses for macromolecular compounds is generally too labour intensive for routine process monitoring. Following the concentrations of selected compounds can, however, give interesting insights for example, Bley et al. [23] found that a phosphate - limited population differentiated into two sub-populations of different DNA - and PHB (poly-3-hydroxybutyrate) - content. The cell-cycle of baker s yeast could be followed by a fluorimetric dye reaction for DNA content in a sample stream from the bioreactor [24]. 

PHA (polyhydroxyalkanoate) 23, 46, 47, 48, 55 phosphate limitation 132 phosphate overplus 54, 56, 94 phosphate reserve 91 phosphate starvation 153... 

Mineral nutrient limitation of microbial degradation has been put forward as an explanation for accumulation of carbon-rich DOM after a Phae-ocystis bloom (Thingstad and Billen 1994). The increase in carbohydrate/POC due to overflow metabolism will give rise to a substrate with a C/P and C/N ratio that is unfavorable to bacteria. Since the C/P ratio of bacteria may be considerably lower than that of phytoplankton (Vadstein et al. 1988), especially phosphate limitation may hamper microbial degradation (Thingstad et al. 

From a physiological point of view, the intracellular concentrations of organic solutes are most relevant, as it is this concentration that affects enzymatic processes. Shifting from unlimited towards limited growth in a batch culture, cell volume often reduces under nitrogen and iron limitation and stays constant under phosphate limitation. Therefore, an increased intracellular DMSP concentration under N or Fe limitation is at least partly due to a reduction in cell volume (Bucciarelli and Sunda 2003 Keller et al. 1999a Stefels and van Leeuwe 1998). 

Wilson WH, Turner S, Mann NH (1998) Population dynamics of phytoplankton and viruses in a phosphate-limited mesocosm and their effect on DMSP and DMS production. Estuar Coast Shelf Sci 46 49-59... 

Ryu, H. W., Hahn, S. K., Chang, Y. K., and Chang, H. N. 1997. Production of poly(3-hydroxybutyrate) by high cell density fed-batch culture of Alcaligenes eutrophus with phosphate limitation. Biotech. Bioeng., 55, 28-32. 

In these equations, x = specific growth rate coefficient, v = specific rate of substrate uptake, t = time, x = biomass concentration, = intracellular substrate, and = concentration of intracellular substrate. Several examples where these equations can be applied include nitrogen limitations in M. citrifolia cultures and phosphate limited growth in C. roseus, N. tahacum, and Papaver somniferum. 

Pan, Y., Subba Rao, D., and Mann, K. (1996a). Changes in domoic acid production and cellular chemical composition of the toxigenic diatom Pseudo-nitzschia multiseries under phosphate limitation. J. Phycol. 32, 371-381. 

Phosphate uptake was studied in phosphate-limited chemostat cultures of Methanobacterium thermoautotrophicum. In cells adapted to nmolar phosphate concentrations the presence of a high-affinity transport system (A m = 25 nM Fmax = 60nmol/min x mg) was demonstrated [273]. 

Denitrification occurs in environments that are deficient in O2. An increase in the ocean s nitrate content will drive higher export production (neglecting, for the moment, the possibility of phosphate limitation). When this increased export production is oxidized in the ocean interior, it will drive more extensive O2 deficiency. This will lead to a higher global rate of denitrification, which, in turn, will lower the ocean s nitrate content. Thus, the sensitivity of denitrification to the O2 content of the ocean interior generates a hypothetical negative feedback that may, like the N2 fixation-based feedback, work to stabilize the nitrate content of the ocean (ToggweUer and Carson, 1995). 

Recently, Hudson et al. (2000) reported the smallest phosphate concentrations to date for any aquatic system (27 pM) in a study using a new, steady-state bioassay technique for estimating orthophosphate concentrations. In phosphate-limited aquatic systems, accurate determination of orthophosphate is critical because it is the only form of phosphorus that can be directly assimilated by primary producers (e.g., Cembella et al., 1984a,b). The standard phosphomolybdate blue method for phosphate determination falls short of this goal, and is widely thought to overestimate... 

Nausch, M., Nausch, G., Wasmund, N., 2004. Phosphorus dynamics during the transition from nitrogen to phosphate limitation in the central Baltic Sea. Marine Ecology Progress Series, 266, 15-25. Nausch, G., Nehring, D., 1996. Baltic Proper, Hydrochemistry. In Third Periodic Assessment of the... 

An additional cost factor in normally phosphate-limited PHA production processes is the expenses for complex nitrogen sources. It was found that supplementation of a defined production medium with small amounts of a complex nitrogen... 

The strains used in this study were grown on a minimal salt medium including glucose as the sole carbon source at 30°C under phosphate limitation which stimulates P(3HB) accumulation. These experiments discriminate between four different states of the P(3HB) granule (1) the native state found... 

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