Invertase activity

Malcolm RE, Vaughan D (1979) Effects of humic acid fraction on invertase activities in plant tissues. Soil Biol Biochem 11 65-72 Malcolm RL (1989) Application of solid-state 13C NMR spectroscopy to geochemical studies of humic substances. In Hayes MHB, MacCarthy P, Malcolm RL, Swift RS (eds) Humic substances II. In search of structure. Wiley, Chichester, UK, pp 339-372... 

Pitombo et al. [3.33] found that 0.010 M succinate buffer at pH 4.6 was the best stabilizer for SC. The influence of three different freezing rates (0.5, 1.5 and 5 °C/min) on the capability of reproduction is shown in Fig. 3.16. During 235 days storage at +25 °C, no measurable decrease in invertase activity was observed, if the RM was below 4 %. With RM approx. 14 %, the invertase activity decreased in 20 days to half and was immeasurable after 57 days, since an insoluble cluster had been formed. A 4 % RM correspond at +25 °C with a monomolecular layer of water. 

Glycosylating Claviceps strains (mostly C. fusiformis) produce most elymoclavine in the form of p-fructofuranosides, which complicates the isolation of elymoclavine. The hydrolysis of fructosides by HCl is not suitable for a large scale process due to the aggressive nature of the acid solution and losses of elymoclavine. A more elegant method is a bioconversion employing the high invertase activity... 

Kim, H. Y., and Suzuki, Y. (1989). Changes in assimilated BC distribution and soluble acid invertase activity of Zinnia elegans induced by Uniconazol an inhibitor of gibberellin biosynthesis. Plant Physiol. 90, 316-321. 

Malcolm, R. E., and Vaughan, D. (1978). Effects of humic acid fractions on invertase activities in plant tissues. Soil Biol. Biochem. 11, 65-72. 

Vaughan, D. (1967b). Effect of humic acid on the development of invertase activity in shces of beetroot tissues washed under aseptic conditions. Humus Planta IV, 268-271. 

Aqueous invertase solutions (soluble and immobilized enzyme) were incubated in acetate buffer (0.010 M, pH5.5) for 20,40,60,80, and 120 min at 30,37,40,45,50, and 55°C. After incubation at each specified time, both forms were assayed for residual activity according to the standard procedure (see Standard Assay for Measuring Invertase Activity). 

Logarithm of Soluble Invertase Activity Against Time at Several Temperatures... 

According to Owusu and Makhzoum (20) AH values of about 200-300kJ/mol would lead to unfolding of the tertiary structure of a protein. However, the Dowex-lx4-200/invertase complex had a AH 37% lower than these values, indicating that the declining invertase activity vs temperature is probably owing to the breakup of the supramolecular structures of invertase rather than to the irreversible unfolding of the macromolecular tertiary structure. 

Application and Principle This procedure is used to determine the invertase activity of enzyme preparations from yeast Saccharomyces sp (Kluyveromyces). The assay is based on a 30-min hydrolysis of sucrose at 30° 0.1° and at pH 4.62. The degree of hydrolysis is determined by measuring the optical rotation of the solution with a polarimeter. 

Amyloglucosidase Activity), 798 Glucose Isomerase Activity, 796 Glucose Oxidase Activity, 798 P-D-Glucosidase Activity, 798 Hemicellulase Activity, 799 Invertase Activity, 800 Lactase (Acid) (P-Galactosidase) Activity, 802... 

Rossi-Alva, J. C., and Miguez Rocha-Leao, M. H. (2003), A strategic study using mutant-strain entrapment in calcium alginate for the production of Saccharomyces cerevisiae cells with high invertase activity, Biotechnol. Appl. Biochem., 38,43-51. 

Of particular interest is recent work by Pitombo et al. [ 181. They studied the effect of moisture content on the invertase activity of freeze-dried S. cerevisiae with respect to monolayer moisture content. Samples with water activity above the monolayer moisture content lost at least 60% of their invertase activity samples with water activity at about the monolayer moisture content retained at least 85% of their original invertase activity. 

R. N. Pitombo, C. Spring, R. F. Passos, M. Tonato, and M. Vitolo, Effect of moisture content on the invertase activity of freeze-dried S. cerrevisiae. Cryobiology 5/ 383-392(1994). 

Figure 2 Promotion of the invertase activity by brassinosteroids compared to kinetin...

Table III Effect of SSHB on sugar-beet total biomass and leaf acid invertase activity...

An increase in total dry mass always corresponded with a rise in invertase activity in young leaves. The older leaves do not act in such a manner and there was no rise in invertase activity. 

The data show that SSHB increased the root dry matter in the same way it did in the other experiments. Simultaneously, we observed an increase in leaf length and leaf area which corresponded with an increase in invertase activity. The higher enzyme activity appeared to be the key to the whole problem. It is well known that acid invertase splits the disaccharide sucrose so that the two monosaccharides formed from it can become building stones for additional leaf substances. That is, glucose is recycled through the Embden-Meyerhof-Parnas pathway. Likewise, fructose is readily available for conversion into fructose 1,6-diphosphate. Subsequently, more leaf area arises which is able to produce more assimilates. The consequence is an increased yield. Thus, photosynthetic efficiency increases considerably. 

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