Potato, phosphate

Compared to native starches, monophosphate esters have a decreased gelatinization temperature range and swell in cold water at a DS of 0.07. Starch phosphates have increased paste viscosity and clarity and decreased retrogradation. Their properties are in many ways similar to those of potato starch, which naturally contains phosphate groups. 

One of the commercial methods for production of lysine consists of a two-stage process using two species of bacteria. The carbon sources for production of amino acids are corn, potato starch, molasses, and whey. If starch is used, it must be hydrolysed to glucose to achieve higher yield. Escherichia coli is grown in a medium consisting of glycerol, corn-steep liquor and di-ammonium phosphate under aerobic conditions, with temperature and pH controlled. 

Potatoes, onions MEKC UV 2 mg kg- 10 mM sodium phosphate, 40 mM cholic acid, pH 7 Maleic hydrazide 127... 

Pome Fruit Types. As with citrus fruit types, the method of sample preparation was modified for the parathion studies. In the earlier studies the DDT-treated apples and pears were scrubbed in a warm 10% solution of trisodium phosphate, and all the peel was removed from the water-rinsed fruit with a household-type potato peeler. The pooled samples of peel and pulp were then processed independently to recover the contained toxicant for subsequent estimation. 

Although arsenic is not an essential plant nutrient, small yield increases have sometimes been observed at low soil arsenic levels, especially for tolerant crops such as potatoes, com, rye, and wheat (Woolson 1975). Arsenic phytotoxicity of soils is reduced with increasing lime, organic matter, iron, zinc, and phosphates (NRCC 1978). In most soil systems, the chemistry of As becomes the chemistry of arsenate the estimated half-time of arsenic in soils is about 6.5 years, although losses of 60% in 3 years and 67% in 7 years have been reported (Woolson 1975). Additional research is warranted on the role of arsenic in crop production, and in nutrition, with special reference to essentiality for aquatic and terrestrial wildlife. 

TAUBERGER, E., FERNIE, A.R., EMMERMANN, M., KOSSMANN, J., WILLMITZER, L., TRETHEWEY, R.N., Antisense inhibition of plastidial phosphoglucomutase provides compelling evidence that potato tuber amyloplasts import carbon from the cytosol in the form of glucose-6-phosphate, Plant J., 2000, 23, 43-53. 

TRETHEWEY, R.N., REISMEIER, J.W., WILLMITZER, L., STITT, M GEIGENBERGER, P., Tuber specific expression of a yeast invertase and a bacterial glucokinase in potato leads to an activation of sucrose phosphate synthase and the creation of a futile cycle, Planta, 1999, 208, 227-238. 

REIMHOLZ, R., GEIGER, M., HAAKE, V., DEITING, U., KRAUSE, K.P., SONNEWALD, U., STITT, M., Sucrose phosphate synthase is regulated by metabolites and protein phosphorylation in potato tubers, in a manner analogous to the enzyme in leaves, Planta, 1994,192, 480-488. 

With the development of enzymatic polymerization in solution, also first accounts for SIP appeared. Loos et al. [350] reported on enzymatic surface polymerization of glucose-l-phosphate with potato phosphorylase as the catalyst resulting in oligo- or poly-(a,l- 4)-D-glucopyranose. As initiator sites, immobilized malto-heptaose was used. Enzymatic grafting of hexyloxyphenol onto chitosan is reported by Payne and coworkers [351]. 

AGIRE computer program for, 249, 79-81, 225-226 comparison to analysis based on rates, 249, 61-63 complex reactions, 249, 75-78 experimental design, 249, 84-85 inhibitor effects, 249, 71-75 potato acid phosphatase product inhibition, 249, 73-74 preliminary fitting, 249, 82-84 prephenate dehydratase product inhibition, 249, 72-73 product inhibition effects, 249, 72-73 prostate acid phosphatase phenyl phosphate hydrolysis, 249, 70 reactions with two substrates, 249, 75-77 reversible reactions, 249, 77-78 with simple Michaelian enzyme, 249, 63-71 [fitting equations, 249, 63] with slow-binding inhibitors, 249, 88 with unstable enzymes, for kinetic characterization, 249, 85-89. 

The fact that glycogen phosphorylase can be used to polymerize amylose was first demonstrated by Schaffner and Specht [110] in 1938 using yeast phosphorylase. Shortly after, the same behavior was also observed for other phosphorylases from yeast by Kiessling [111, 112], muscles by Cori et al. [113], pea seeds [114] and potatoes by Hanes [115], and preparations from liver by Ostern and Holmes [116], Cori et al. [117] and Ostern et al. [118]. These results opened up the field of enzymatic polymerizations of amylose using glucose-1-phosphate as monomer, and can be considered the first experiments ever to synthesize biological macromolecules in vitro. 

Fig. 6 Priming activity of glucose and maltooligosaccharides in the enzymatic polymerization using potato phosphorylase and glucose-1-phosphate as monomer [124] - Reproduced by permission of Portland Press Ltd.

Tablets were prepared either with an insoluble (dicalcium phosphate dihydrate), a soluble (6-lactose) or a moderately soluble filler-binder (a-lactose monohydrate). As a disintegrant four different starches (com, rice, potato and tapioca) were used. As a comparison the effect of two super-disintegrants (crospovidone and sodium starch glycolate) was studied. The disintegrants were added at two concentration levels. The compression load was adjusted in order to obtain tablets with comparable initial cmshing strengths.

Tablets prepared with dicalcium phosphate dihydrate increased in crushing strength due to increasing temperatures (A,sir(s) ). The relative humidity had a negative effect on the SIR of crushing strength of the tablets prepared with dicalcium phosphate dihydrate, except for the tablets prepared with potato starch. Also a significant interaction between the temperature and relative humidity effect was seen (A3,sir(S) 0), indicating that the effect of the relative humidity on the SIR of crushing strength of dicalcium phosphate dihydrate tablets depended on the level of temperature and vice versa.

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