Soil Invertase
Invertase catalyzes the hydrolysis of sucrose to glucose and fructose due to β-fructofuranosides, predominantly available in microorganisms, animals, and plants (Kiss and Peterfi 1959; Skujins 1976; Alef and Nannipieri 1995). Invertase brings out all hydr
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Soil Invertase
Introduction Invertase catalyzes the hydrolysis of sucrose to glucose and fructose due to β-fructofuranosides, predominantly available in microorganisms, animals, and plants (Kiss and Peterfi 1959; Skujins 1976; Alef and Nannipieri 1995). Invertase brings out all hydrolysis of sucrose under either acidic or alkaline conditions (Splading 1979). Very little information is available on invertase activity in soil polluted by agrobased industries. Ross and Speir (1984) reported that soil temperature influenced soil invertase activity. Invertase activity was greater in desert remnant than in xeriscape sites (Douglas and Oleksyszyn 2002). Increased invertase activity was reported in urban expansions into wild lands (Douglas and Oleksyszyn 2002), soil treated with effluents of pulp and paper mills (Kannan and Oblisami 1990b; Chinnaiah et al. 2002), cotton ginning (Narasimha 1997), and hexachlorocyclohexane and its isomers (Srimathi and Karanth 1989). By contrast, invertase activity was reduced when soils were stored and air dried (Hoffman and Hoffman 1955), with the addition of toluene (Kiss and Peterfi 1959), insecticides (El Hamady and Sheloa 1999; Palaniappan and Balasubramanian 1985), cement dust from the cement industry (Shanthi 1993), and soil organic matter (Malcolm and Vaughan 1979). Bezuglova et al. (1999) reported that the higher the content of carbonates in parent rocks, the lower the activity of invertase in the buried mass, and vice versa.
Enzyme Assay Triplicate samples of soils with/without effluent discharges were incubated in the manner mentioned in Chap. 4; soil samples were withdrawn at desired intervals at 0, 10, 20, 30, and 40 days to determine invertase activity by the method described © Springer International Publishing Switzerland 2017 N.R. Maddela et al., Soil Enzymes, SpringerBriefs in Environmental Science, DOI 10.1007/978-3-319-42655-6_8
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8 Soil Invertase
by Tu (1982). Five grams of soil samples were transferred to test tubes (25 × 200 mm); to this 1 ml of toluene was added. All the contents in the tubes were mixed thoroughly, and after 15 min, 6 ml of 18 mmol/l sucrose in 0.2 M acetate buffer (pH 5.5) was added. In another set, soil samples were treated in the same manner by replacing starch with acetate buffer without substrate. All the tubes were incubated for 6 h. The suspension was filtered by Whatman No. 1 filter paper, and the amount of reducing sugar content in the filtrate was determined by the Nelson–Somagyi method (1944) using an Elico digital spectrophotometer. Similarly, another three sets of control soil samples were treated with 10, 50, and 100 % effluents, respectively, and invertase activities were assessed.
Impact of Effluents Invertase enzyme activity was expressed as the amount of glucose formed from the substrate (18 mM sucrose). The activity of invertase in test and control soil samples was measured by incubating the samples in the presence of substrate (18 mM sucrose), and the results are listed in Table 8.1. The test sample showed higher activity over c
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