Showing papers on "Amylase published in 2001"
TL;DR: Levels of red cell, serum acid, and alkaline phosphatases, serum amylase, alanine and aspartate transferase and bilirubin were examined in streptozotocin-induced diabetic rats treated with garlic oil and compared with the corresponding levels in diabetic control rats, normal rats and normal rats on garlic oil.
Abstract: Levels of red cell, serum acid, and alkaline phosphatases, serum amylase, alanine and aspartate transferase and bilirubin were examined in streptozotocin-induced diabetic rats treated with garlic oil and compared with the corresponding levels in diabetic control rats, normal rats and normal rats on garlic oil. Values of tissue amylase and total protein were also assessed from the pancreas, liver, and kidney. Treatment of diabetic rats with garlic oil significantly decreased the red cell phosphatase (p < 0.01), serum acid and alkaline phosphatase (p<0.001) when compared to diabetic control rats. Serum alanine and asparate transferases were significantly (p<0.001) decreased as well as serum amylase (p<0.002) in garlic oil treated diabetic rats as compared with diabetic control rats. When treated with garlic oil, however, diabetic and normal rats showed significant increase (p <0.05) in the amylase levels of the pancrease, liver, and kidney.
178 citations
TL;DR: In this paper, the effect of cadmium on the content of starch and sugars, and changes in the enzymes of sugar metabolism were studied in growing seedlings of rice (Oryza sativa L.) cultivars Ratna and Jaya.
Abstract: The effect of cadmium on the content of starch and sugars, and changes in the activities of the enzymes of sugar metabolism were studied in growing seedlings of rice (Oryza sativa L.) cultivars Ratna and Jaya. During a 5- to 20-d exposure at 100 μM or 500 μM Cd(NO3)2 in the growth medium an increase in the content of total soluble sugars and reducing sugars, and decrease in the content of non-reducing sugars was observed. Cd-induced increase in the sugar content was greater in shoots than in roots. No definite pattern of changes in starch content or in α-amylase activity was observed. Presence of 100 or 500 μM Cd(NO3)2 increased the activities of sucrose degrading enzymes, acid invertase and sucrose synthase, whereas the activity of sucrose phosphate synthase declined.
169 citations
TL;DR: Responding surface methodology was employed to study the cumulative interactive effect of the macronutrients of the media and to optimize their concentration to enhance the production of maltooligosaccharide-forming amylase from Bacillus circulans GRS 313, suggesting that this was the principal experimental variable having the greatest effect on the production.
155 citations
TL;DR: Although alpha-amylase is present in high activity in digestive fluid, the enzymic hydrolysis of starch may be a limiting factor in carbohydrate digestion because of factors related to the physico-chemical properties of starchy foods.
136 citations
TL;DR: Different differences were found in the optimal pH for amylase activity as well as in sensitivity to temperature, with resistance to heating very low in B. boops and very high in D. annularis.
135 citations
TL;DR: P pH in AM is in good agreement with the optimal pH of amyl enzyme, located in this compartment, but the activity of proteinases, including the ability to degrade amylase, in such an environment is low.
Abstract: Compartmentalization of proteinases, amylases, and pH in the midgut of Nauphoeta cinerea Oliv. (Blattoptera:Blaberidae) was studied in order to understand the organization of protein and starch digestion. Total proteolytic activity measured with azocasein was maximal at pH 11.5 both in anterior (AM) and posterior (PM) halves of the midgut, but the bulk of activity (67%) was found in PM. Total AM and PM preparations were fractionated on a Sephadex G-50 column and further analysed by means of activity electrophoresis and specific inhibitors and activators. The major activity in PM was classified as an unusual SH-dependent proteinase with Mr 24,000 and pH optimum with synthetic substrate BApNA at 10.0. The enzyme was 43-fold activated in the presence of 1 mM DTT, insensitive to synthetic inhibitors of serine (PMSF, TLCK, TPCK) and cysteine (IAA, E-64) proteinases, strongly inhibited by STI, and displayed four active bands on zymograms. In PM, activities of trypsin-like, chymotrypsin-like, subtilisin-like, and cysteine proteinases were observed. Aspartic and metalloproteinases were not detected. In AM, activity of unusual SH-dependent proteinase also dominated and activity of chymotrypsin-like proteinase was observed, but their levels were much lower than in PM. Distribution of amylase activity, exhibiting an optimum at pH 6.0, was quite the opposite. The major part of it (67%) was located in AM. Treatment of amylase preparation with proteinases from AM and PM reduced amylase activity twofold. pH of the midgut contents was 6.0–7.2 in AM, 6.4–7.6 in the first and 8.8–9.3 in the second halves of PM. Thus, pH in AM is in good agreement with the optimal pH of amylase, located in this compartment, but the activity of proteinases, including the ability to degrade amylase, in such an environment is low. Active proteolysis takes place in the second half of PM, where pH of the gut is close to the optimal pH of proteinases. Arch. Insect Biochem. Physiol. 48:206–216, 2001. © 2001 Wiley-Liss, Inc.
134 citations
TL;DR: Thermostable amylolytic enzymes have been currently investigated to improve industrial processes of starch degradation and Nocardiopsis sp.
123 citations
TL;DR: Trypsin precursors are observed inside small vesicles near the apical plasma membrane of posterior midgut cells, suggesting an exocytic mechanism of secretion, followed by putative trypsin activation.
119 citations
TL;DR: Background: The diagnosis of acute pancreatitis relies heavily on a raised amylase, so it is important to understand the role that this enzyme plays in the development of pancreatitis.
Abstract: Background: The diagnosis of acute pancreatitis relies heavily on a raised amylase.
Methods: In the present study patients were prospectively categorized, without knowledge of pancreatic enzyme levels, into acute pancreatitis (AP; n = 51), disease controls (n = 35), indeterminate as to pancreatitis (n = 189) or exclusions (non-pancreatitis diseases where amylase may be elevated; n = 53).
Results: Enzyme levels were analysed by receiver operator characteristics (ROC) curves, with specificity > 80%. Day 1 serum lipase gave the greatest diagnostic accuracy (area under ROC curve = 0.128; P = 0.041 vs serum amylase). At the calculated diagnostic threshold of 208 U/L, lipase gave a sensitivity of 67% and a specificity of 97%. Other diagnostic thresholds (day 1) were: serum total amylase, 176 U/L (ROC 0.104, sensitivity 45%, specificity 97%), urinary total amylase, 550 U/L (ROC 0.108, sensitivity 62%, specificity 97%) and serum pancreatic isoamylase, 41 U/L (ROC 0.107, sensitivity 63%, specificity 85%). At delayed diagnosis (3 days) no enzyme was superior to lipase. The combination of lipase and amylase did not increase diagnostic accuracy.
Conclusion: Serum lipase is recommended for diagnosis of AP, both early and late in the disease. Although highly specific when elevated, all pancreatic enzymes have low sensitivity for diagnosis.
115 citations
TL;DR: Lactobacillus manihotivorans LMG 18010T, a new amylolytic l(+) lactic acid producer, was investigated and compared with starch fermentation by Lact.
Abstract: Lactic acid fermentation of starch by Lactobacillus manihotivorans LMG 18010T, a new amylolytic L(+) lactic acid producer, was investigated and compared with starch fermentation by Lact. plantarum A6. At non-controlled pH, growth and lactic acid production from starch by Lact. manihotivorans LMG 18010T lasted 25 h. Specific growth and lactic acid production rates continuously decreased from the onset of the fermentation, unlike Lact. plantarum A6 which was able to grow and convert starch product hydrolysis into lactic acid more rapidly and efficiently at a constant rate up to pH 4.5. In spite of complete and rapid starch hydrolysis by Lact. manihotivorans LMG 18010T during the first 6 h, only 45% of starch hydrolysis products were converted to lactic acid. When pH was maintained at 6.0, lactic acid, amylase and final biomass production by Lact. manihotivorans LMG 18010T increased markedly and the fermentation time was reduced by half. Under the same conditions, an increase only in amylase production was observed with Lact. plantarum A6. When grown on glucose or starch at pH 6.0, Lact. manihotivorans LMG 18010T had an identical maximum specific growth rate (0.35 h(-1)), whereas the maximum rate of specific lactic acid production was three times higher with glucose as substrate. Lactobacillus manihotivorans LMG 18010T did not produce amylase when grown on glucose. Based on the differences in the physiology between the two species and other amylolytic lactic acid bacteria, different applications may be expected.
105 citations
TL;DR: It is concluded that acute alcohol consumption causes a decrease in SWS flow rate, which results in impaired output of total protein and amylase, as well as in a decreases in the output of electrolytes.
Abstract: Objective: The aim of our study was to evaluate the effects of acute alcohol consumption on saliva secretion rate and selected salivary parameters in healthy nonalcoholic volunteers. Study Design: Twenty-four volunteers (37.7 ± 9.6 years, mean ± SD) consumed 0.6 g or 0.7 g alcohol/kg of body weight (for women and men, respectively) in a soft drink. Saliva samples were collected, first (S0) before any alcohol was consumed, 45 minutes after consumption (S1) and, finally, 60 minutes after S1 (S2). Flow rates of both resting whole saliva and paraffin-stimulated (SWS) whole saliva were assessed. SWS was assessed for amylase, total protein, inorganic phosphate (PO43–), sodium (Na+), potassium (K+), and calcium (Ca2+) content. Results: SWS, but not resting whole saliva (in milliliters/minute), decreased significantly after consumption of alcohol. Amylase activity (P =.010) and the concentrations of Na+ (P =.000) and Ca2+ (P =.002) decreased significantly between S0 and S1. When SWS was analyzed for output, the total protein concentration (S0 to S1, P =.000; S0 to S2, P =.033) and amylase activity (S0 to S1, P =.000) decreased significantly. Further, the output of all the studied electrolytes decreased significantly as blood alcohol concentration increased. Conclusions: We conclude that acute alcohol consumption causes a decrease in SWS flow rate. The decrease in flow rate also results in impaired output of total protein and amylase, as well as in a decrease in the output of electrolytes.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;92:292-8)
TL;DR: Calcofluor-treated larvae lacking a PM were shown to lose the decreasing gradient of trypsin and chymotrypsin observed along the midgut of control larvae, thought to be formed by a countercurrent flux of fluid.
Abstract: A peritrophin from the Spodoptera frugiperda peritrophic membrane (PM) and microvillar proteins from S. frugiperda anterior midgut cells were isolated and used to raise antibodies in a rabbit. These antibodies, as well as a Tenebrio molitor amylase antibody that cross-reacts with S. frugiperda amylases, and wheat-germ aglutinin were used in immunolocalization experiments performed with the aid of confocal fluorescence and immunogold techniques. The results showed that the peritrophin was secreted by anterior midgut columnar cells in vesicles pinched-off the microvilli (microapocrine secretion). The resulting double membrane vesicles become single membrane vesicles by membrane fusion, releasing peritrophin and part of the amylase and trypsin. The remaining membranes still containing microvillar proteins and membrane-bound amylase and trypsin are incorporated into a jelly-like material associated with PM. Calcofluor-treated larvae lacking a PM were shown to lose the decreasing gradient of trypsin and chymotrypsin observed along the midgut of control larvae. This gradient is thought to be formed by a countercurrent flux of fluid (in the space between PM and midgut cells) that powers enzyme recycling.
TL;DR: Results suggest that AbpA of Streptococcus gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylases-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonII.
Abstract: Interactions between bacteria and salivary components are thought to be important in the establishment and ecology of the oral microflora. alpha-Amylase, the predominant salivary enzyme in humans, binds to Streptococcus gordonii, a primary colonizer of the tooth. Previous studies have implicated this interaction in adhesion of the bacteria to salivary pellicles, catabolism of dietary starches, and biofilm formation. Amylase binding is mediated at least in part by the amylase-binding protein A (AbpA). To study the function of this protein, an erythromycin resistance determinant [erm(AM)] was inserted within the abpA gene of S. gordonii strains Challis and FAS4 by allelic exchange, resulting in abpA mutant strains Challis-E1 and FAS4-E1. Comparison of the wild-type and mutant strains did not reveal any significant differences in colony morphology, biochemical metabolic profiles, growth in complex or defined media, surface hydrophobicity, or coaggregation properties. Scatchard analysis of adhesion isotherms demonstrated that the wild-type strains adhered better to human parotid-saliva- and amylase-coated hydroxyapatite than did the AbpA mutants. In contrast, the mutant strains bound to whole-saliva-coated hydroxyapatite to a greater extent than did the wild-type strains. While the wild-type strains preincubated with purified salivary amylase grew well in defined medium with potato starch as the sole carbohydrate source, the AbpA mutants did not grow under the same conditions even after preincubation with amylase. In addition, the wild-type strain produced large microcolonies in a flow cell biofilm model, while the abpA mutant strains grew much more poorly and produced relatively small microcolonies. Taken together, these results suggest that AbpA of S. gordonii functions as an adhesin to amylase-coated hydroxyapatite, in salivary-amylase-mediated catabolism of dietary starches and in human saliva-supported biofilm formation by S. gordonii.
TL;DR: This is the first report showing that IAA can delay starch degradation, possibly affecting the activity of hydrolytic enzymes such as β-amylase (EC 3.2.1.2).
Abstract: In order to observe the effect of indole-3-acetic acid (IAA) on carbohydrate metabolism, unripe banana (Musa acuminata AAA, cv. Nanicao) slices were infiltrated with the hormone and left to ripen under controlled conditions. The climacteric respiration burst was reduced by the action of IAA, and starch degradation and sucrose formation were delayed. Sucrose synthase (SuSy; EC 2.4.1.13) and sucrose-phosphate synthase (SPS; EC 2.4.1.14) activities and transcript levels were not affected, indicating that prevention of sucrose accumulation was not related to sucrose-metabolizing enzymes. Impairment of sucrose synthesis could be a consequence of lack of substrate, since starch degradation was inhibited. The increase in activity and transcript level of beta-amylase was delayed, indicating that this enzyme could be important in starch-to-sucrose metabolism in bananas and that it might be, at least partially, controlled at the transcriptional level. This is the first report showing that IAA can delay starch degradation, possibly affecting the activity of hydrolytic enzymes such as beta-amylase (EC 3.2.1.2).
TL;DR: Study of grain colour in relation to pericarp alpha -amylase activity showed that the enzyme could persist in non-green grains in levels sufficient to affect the Hagberg value, and two factors thought to promote PMAA, grain drying rate and transient changes in temperature in early development, were studied.
TL;DR: Naranang et al. as mentioned in this paper investigated the influence of various carbon and nitrogen sources on α-amylase production in batch fermentation in shake flasks and found that starch and tryptone were the ideal carbon sources, respectively.
Abstract: S. NARANG AND T. SATYANARAYANA. 2001.
Aims:α-Amylase production by a newly isolated thermophile, Bacillus thermooleovorans, was studied under different cultivation conditions.
Methods and Results: The influence of various carbon and nitrogen sources on α-amylase production was quantified in batch fermentation in shake flasks. Starch and tryptone were observed to be the ideal carbon and nitrogen sources, respectively. Cultivation of the organism in a chemically defined medium consisting of glucose, riboflavin, cysteine, MgSO4, K2HPO4 and NaCl led to a near twofold increase in the production of α-amylase in comparison with that in the complex medium. The increase in enzyme production was achieved using vitamins and amino acids. When the organism was grown in a laboratory fermenter in the optimized complex medium, the noticeable effects were the near abolition of the lag phase, a 2·2-fold increase in enzyme production and a reduction in optimal production time from 12 to 4–5 h.
Conclusions: Enhancement of amylase production was achieved under various cultivation conditions.
Significance and Impact of the Study:Bacillus thermooleovorans produces a calcium-independent and thermostable amylase which can find use in starch saccharification.
TL;DR: In this article, the influence of α-amylase on bread crumbs and on wheat starch gels was investigated taking into account different levels of structural hierarchy, and the effect of α amylase was shown to enhance the initial firmness of bread and reduce the firming rate of wheat gels on aging.
Abstract: The influence of an antistaling α-amylase on bread crumb and on wheat starch gels was investigated taking into account different levels of structural hierarchy. Bread was prepared by a conventional baking procedure. Starch gels were produced by heating a concentrated starch dispersion in closed molds. Bread and starch gels were characterized by compression tests, light microscopy (LM), differential scanning calorimetry, and X-ray measurements. The α-amylase enhanced the initial firmness of starch gels and reduced the firming rate of bread and starch gels on aging. LM revealed that amylose and amylopectin phase-separated within the starch granules and that freshly baked control bread and starch gels showed weak birefringence which became more intense during aging. Amylase-containing bread and starch gels exhibited strong birefringence in the amylose rich region of the granules directly after baking which did not significantly increase during aging. The enzyme hindered the retrogradation of amylope...
TL;DR: Results suggest that little to no beta-amylase activity is required to maintain normal starch levels, rates of phloem exudation, and overall plant growth.
Abstract: Despite extensive biochemical analyses, the biological function(s) of plant beta-amylases remains unclear. The fact that beta-amylases degrade starch in vitro suggests that they may play a role in starch metabolism in vivo. beta-Amylases have also been suggested to prevent the accumulation of highly polymerized polysaccharides that might otherwise impede flux through phloem sieve pores. The identification and characterization of a mutant of Arabidopsis var. Columbia with greatly reduced levels of beta-amylase activity is reported here. The reduced beta-amylase 1 (ram1) mutation lies in the gene encoding the major form of beta-amylase in Arabidopsis. Although the Arabidopsis genome contains nine known or putative beta-amylase genes, the fact that the ram1 mutation results in almost complete loss of beta-amylase activity in rosette leaves and inflorescences (stems) indicates that the gene affected by the ram1 mutation is responsible for most of the beta-amylase activity present in these tissues. The leaves of ram1 plants accumulate wild-type levels of starch, soluble sugars, anthocyanin, and chlorophyll. Plants carrying the ram1 mutation also exhibit wild-type rates of phloem exudation and of overall growth. These results suggest that little to no beta-amylase activity is required to maintain normal starch levels, rates of phloem exudation, and overall plant growth.
TL;DR: In this article, rice brain oil was extracted by enzyme-assisted aqueous extraction under optimized extraction conditions using mixtures of ProtizymeTM (protease), PalkodexTM (α-amylase), and cellulase (crude cellulase), with 10 g of rice brain in 40 mL distilled water, pH 7.0, temperature 65°C, extraction time 18 h with constant shaking at 80 rpm.
Abstract: In the present study, rice brain oil was extracted by enzyme-assisted aqueous extraction under optimized aqueous extraction conditions using mixtures of ProtizymeTM (protease; Jaysons Agritech Pvt. Ltd., Mysore, India), PalkodexTM (α-amylase; Maps India Ltd., Ahmedabad, India), and cellulase (crude cellulase; Central Drug House, Delhi, India). The optimal conditions used were: mixtures of amylase (80 U), protease (368 U), and cellulase (380 U), with 10 g of rice brain in 40 mL distilled water, pH 7.0, temperature 65°C, extraction time 18 h with constant shaking at 80 rpm. Centrifugation of the mixture at 10,000×g for 20 min yielded a 77% recovery of the oil.
TL;DR: The technique of three phase partitioning was used to purify a wheat germ bifunctional protease/amylase inhibitor and the single step led to 25-fold purification with an activity recovery of 85%.
TL;DR: A semi-continuous production of maltose from a highly concentrated substrate with the immobilized sweet potato β-amylase and Bacillus brevis pullulanase could be obtained at pH 6.0 and 60°C for 14 days at a higher yield using a horizontal rotary column reactor.
TL;DR: The maltohexaose-forming alpha-amylase, of B. stearothermophilus US100, was purified to homogeneity by a combination of osmotic shock, starch adsorption and anion exchange chromatography, allowing the identification of a single open reading frame encoding a 549 amino acid protein.
TL;DR: The results obtained suggest that, at least for the cultivars analysed, there is a high general amylase activity around the fourth day of germination, indicating that germination could stop at this moment, ensuring that hydrolitic enzyme activity required in the brewing process is met.
TL;DR: In this article, the matrix effects of starch to water ratio, temperature and time on gelatinization, swelling and enzymatic ( alpha -amylase) hydrolysis of five starches (waxy maize, maize, wheat, tapioca and potato) were investigated.
TL;DR: In this paper, the effect of starch conversion on the susceptibility of potato granules to α-amylase was studied by direct sampling at different pasting times corresponding to different points on the RVA profile of a 6.4% (w/w) suspension of starch in distilled water.
Abstract: The effect of starch conversion on the susceptibility of potato granules to α-amylase was studied by direct sampling at different pasting times corresponding to different points on the RVA profile of a 6.4% (w/w) suspension of starch in distilled water. Native granules showed high resistance to α-amylase with 8.6 ± 0.4% digestibility for a 6 h incubation period with the enzyme. When the suspension was heated to 60 °C, the digestibility increased to 53.5 ± 0.7% although, at this temperature, there was still no noticeable increase in the measured viscosity (≤ 0.040 Pa.s). The material sampled after a pasting time corresponding to the RVA peak viscosity showed a digestibility of 88.4 ± 0.5%. This suggested, owing to the expected retrogradation of amylose on cooling, the quasi-total susceptibility of amylopectin to enzymatic digestion at this pasting stage. The effect of ions on the swelling of potato starch was used to assess whether the decrease of the swelling of the granules in the presence of NaCl was paralleled by an increase in resistance to α-amylase. A small (∼ 6.1%) but significant decrease in the digestibility of pasted starch was observed in the presence of salt. Finally, the effect of the retrogradation of the amylopectin fraction on its digestibility was assessed in extruded potato starch ribbons containing 35% (w/w) water and stored at different temperatures. After 14 days of storage, the digestibility decreased from 77.0 ± 0.9% in the freshly extruded samples to between 28.0 ± 1.7% and 42.1 ± 0.3%, depending on the storage temperature. This suggested a measurable difference in the α-amylase susceptibility between the A and B polymorphs of retrograded amylopectin.
TL;DR: The routine measurement of pleural fluid serum amylase levels is neither clinically indicated nor cost-effective and is suggested only if there is a pretest suspicion of acute pancreatitis, chronic pancreatic disease, or esophageal rupture.
Abstract: Background The routine measurement of pleural fluid amylase is frequently recommended, but the cost-effectiveness of this procedure is unknown. Methods To assess the utility of routine measurement of pleural fluid amylase in evaluating pleural effusions, we measured amylase, glucose, lactate dehydrogenase, and protein levels and blood cell counts in 379 patients undergoing thoracentesis during a 22-month period from 1997 to 1999. Of these, 199 had effusions after cardiac surgery; 61, malignant; 48, transudative; 28, parapneumonic; 2, chylous; 2, rheumatoid; 1, tuberculous; and 1, from chronic pleuritis. There were 37 exudates of unknown origin. Results Measurement of pleural fluid amylase levels did not assist in determining the origin of the effusion in any of the patients. Amylase levels greater than 100 U/L (normal serum level in our laboratory is 30-110 U/L) were found in 5 (1.3%) of 379 patients: 1 patient with congestive heart failure (amylase, 173 U/L), 2 with post–cardiac surgery effusions (144 U/L and 130 U/L), 1 with pneumonia (109 U/L), and 1 with lung cancer (105 U/L). Conclusions The routine measurement of pleural fluid amylase levels is neither clinically indicated nor cost-effective. We suggest that pleural fluid serum amylase levels be measured only if there is a pretest suspicion of acute pancreatitis, chronic pancreatic disease, or esophageal rupture.
TL;DR: 4-alpha-D-Kojibiosyl-glucose, kojitriose and kojitetraose, the principal kojioligosaccharides synthesized, were not hydrolyzed by salivary amylase, artificial gastric juice, pancreatic amyl enzyme, or small intestinal enzymes.
TL;DR: Zabrotes subfasciatus larvae possess three α -amylase isoforms determined by in gel assays following SDS-PAGE, which suggested that α AI-1 is involved in amylase induction and that it has inhibitory activity against the constitutive amylases, when starch granules are used as substrate.
TL;DR: Under optimal condition, this enzyme was able to attack the α-1,4 linkages in soluble starch, amylose, isylopectin and glycogen to generate maltopentaose as the major end product.
TL;DR: Trypsinogen-2 and trypsin-2-α1antitrypsin complex in serum with lipase and amylase displayed the best accuracy for predicting a severe AP already at admission, which makes these markers superior for clinical purposes.