higher C and N degradation capacities than grasses. They also increase soil organic matter, the C and N fractions, and soil enzyme activities to a greater extent than grasses. These increases provide an effective source of C and N for crops and soil
until observation. For the root squash step, the roots are hydrolyzed in hydrochloric acid or a combination of hydrochloric acid and ethanol. Alternatively, cell walls may be broken down by enzyme digestion using combinations of cellulase, cytohelicase
Chinese water chestnuts retain crispness during heating much better than most vegetables. To help explain this unusual property of water chestnuts, a study was conducted to determine their cell wall composition and to assay some of the enzymes that may be involved in hydrolysis of cell walls and starch. Water chestnuts were found to contain high levels of β-1,3-glucanase and β-glucosidase but low cellulase. A number of other enzymes were detected including invertase, α- and β-galactosidases and α-mannosidase. A rather high level of amylase is present in water chestnuts and most of the activity appears to be due to β-amylase. Water chestnuts contain low pectinesterase but a moderate amount of polygalacturonase which was purified and characterized. It is an exoenzyme that does not require Ca2+ for activity in contrast to most other exopolygalacturonases. An unusual property of the water chestnut polygalacturonase is its stability to heat, with retention of most of its activity after heating at 80°C for 5 min. The cell walls of water chestnuts contain low pectin which is solubilized slowly by pectic enzymes.
Abstract
The conditions for extracting and assaying tomato (Lycopersicon esculentum Mill.) polygalacturonases (PG I and PG II) have been re-examined. The enzymes were not extracted by water at pH 3, which allowed washing of the cell wall fraction to remove the soluble components that interfere in the PG assay. The extractability of PG in water increased as the pH was lowered or raised from 3, with optima near pH 1.8 and 6.5. Only PG II was extracted by water at pH 1.8, whereas both isoenzymes were extracted at pH 6.5. The extractabilities of the PGs were increased by NaCl, but the amount of total activity extracted by 1.2 m NaCl was independent of pH between 2 and 9. Extracts in 1.2 m NaCl of pH 3 washed cell walls from ripe tomatoes could be assayed without concentration or dialysis. Higher PG activity was recovered when extracts were concentrated by ultrafiltration than by precipitation with (NH4)2SO4. The results indicate that the isoenzyme composition and recovery of PG from tomatoes were dependent on extraction and concentration procedures.
enzymatic solution under vacuum was developed ( Bruemmer, 1981 ). The enzyme, pectinase or cellulase, digested the albedo, facilitating peel removal ( Baker and Bruemmer, 1989 ; Bruemmer, 1981 ; Ismail et al., 2005 ; Pretel et al., 1997 ). Unfortunately
berries, if available, would benefit small-scale producer’s decision-making processes and juice recoveries. The process of producing juice varies and may include freezing, heating, and enzyme treatments ( Howard et al., 2012 ). Berries can be frozen after
/mat, which were the first reports of success using direct enzyme applications of specific enzymes. Our hypothesis is that application of enzymes might directly alter or degrade the diverse organic materials contributing to SWR in a manner to reduce their
also thank Pia Nel, Susan Agenbag, and Desiree de Koker for their assistance with pigment and enzyme analysis, Hortec and ARC Infruitec-Nietvoorbij for supplying meteorological data, and SummerCourt and Imibala Farms for donation of plant material. Any
nonenzymatic components that can be divided into two different types of repair mechanisms: 1) production of antioxidants or antioxidant enzymes that directly react with and scavenge AOS, including superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase
superoxide dismutase (SOD), peroxidase (POD), glutathione reductase (GR), and other antioxidative enzymes were detected in both horse gram ( Macrotyloma uniflorum ) and bengal gram ( Cicer arietinum ) subjected to Pb, and the levels of enzymes were dependent