Glucoamylase Activity Research Articles

High-Throughput Sequencing Analysis of Microbiota and Enzyme Activities in Xiaoqu from Seven Provinces in Southern China.

Xiaoqu, a pivotal starter in baijiu fermentation, provides the most microflora and enzymes to initiate and maintain baijiu brewing. This study aims to explore the differences in microbiota and enzyme activities among Xiaoqu samples from seven provinces in southern China using high-throughput sequencing, plate isolation, and activity detection. The analyses revealed significant differences in bacterial and fungal communities across the samples. A total of 22 bacterial species and 17 target fungal species were isolated and identified. Predominant bacteria included Bacillus (Bacillus subtilis) and lactic acid bacteria (LABs), while the fungal communities were primarily composed of yeasts (Saccharomyces cerevisiae) and various molds. The activities of α-amylase and glucoamylase varied significantly among the samples, and samples from HN1 and GZ2 exhibited the highest activities. Correlation analyses highlighted the pivotal role of LABs in maintaining acidity and the importance of molds and yeasts in the saccharification and fermentation processes. These findings shed light on the microbial composition and diversity of Xiaoqu and the critical role of microbes in baijiu production. Moreover, they suggested potential microbial resources for developing artificial Xiaoqu via synthetic microbial community in the future, enhancing baijiu fermentation efficiency and overall product quality.

Production of thermostable recombinant cutinase using mixed food waste: A sustainable approach toward environmental remediation

Recently, there has been a significant surge in the utilization of single-use plastics. Cost-effective degradation of plastics is imperative to reduce the ecological burden. This study explores the overproduction and characterization of a PET (Polyethylene terephthalate) a degrading enzyme, cutinase, in the E. coli BL21 (DE3) expression system. Furthermore, this research delves into the utilization of mixed food waste (MFW) as a sustainable substrate for the production of Cutinase, replacing commercial glucose. The newly isolated strain, Aspergillus terreus, showed the highest glucoamylase activity of 76.10 ± 3.10 U/g. The enzymatic hydrolysis of mixed food waste resulted in 50 ± 0.4 g/L of glucose, used as feedstock for cutinase production. The crude enzyme activity was evaluated to be 11.64 U/mg, and a further 14.11-fold purification was achieved through IMAC. The purified recombinant enzyme showed its maximum activity at 70℃ and pH 7. The metal ion Na+ increased the enzyme activity by 26 % while Zn+2 significantly inhibited the same (47 % inhibition); other ions had little or no effect. Taguchi’s optimization of five variables showed that the concentration of food waste hydrolysate has the maximum impact on enzyme production. The treatment of commercially available PET bottles using the purified enzyme showed characterizable surface degradation effects. This is the first time food waste hydrolysate was used as a sole carbon source to produce recombinant cutinase. This approach can potentially pave the way for sustainable biorefinery and waste management.

Screening, identification, and characterization of molds for brewing rice wine: Scale-up production in a bioreactor.

Rice wine, well known for its unique flavor, rich nutritional value, and health benefits, has potential for extensive market development. Rhizopus and Aspergillus are among several microorganisms used in rice wine brewing and are crucial for determining rice wine quality. The strains were isolated via Rose Bengal and starch as a combined separation medium, followed by oenological property and sensory evaluation screening. The strain exhibiting the best performance can be screened using the traditional rice wine Qu. The strains YM-8, YM-10, and YM-16, which exhibited strong saccharification and fermentation performance along with good flavor and taste, were obtained from traditional rice wine Qu. Based on ITS genetic sequence analysis, the YM-8, YM-10, and YM-16 strains were identified as Rhizopus microsporus, Rhizopus arrhizus, and Aspergillus oryzae. The optimum growth temperature of each of the three strains was 30°C, 32°C, and 30°C, and the optimum initial pH was 6.0, 6.5, and 6.5, respectively. The activities of α-amylase, glucoamylase, and protease of YM-16 were highest at 220.23±1.88, 1,269.04±30.32, and 175.16±1.81 U/g, respectively. The amino acid content of rice wine fermented in a 20-L bioreactor with the three mold strains was higher than that of the control group, except for arginine, which was significantly lower than that of the control group. The total amino acid content and the total content of each type of amino acid were ranked as YM-16 > YM-8 > YM-10 > control group, and the amino acid content varied greatly among the strains. The control group had a higher content, whereas YM-8 and YM-16 had lower contents of volatile aroma components than the control group and had the basic flavor substances needed for rice wine, which is conducive to the formation of rice wine aroma. This selected strain, YM-16, has strong saccharification and fermentation ability, is a rich enzyme system, and improves the flavor of rice wine, thereby demonstrating its suitability as a production strain for brewing.

Carbohydrase activity in proximal and distal segments of small intestine in health, irritated bowel syndrome and enteropathy with membrane digestion disturbance

Diagnostics of enteropathy with membrane digestion disturbance (EMDD) is based on the evaluation of carbohydrase activity in duodenal mucosa (DM). There is no information about diagnostic value of ileum mucosa (IM) carbohydrases.
 Aim. Assess the diagnostic value of carbohydrases activity in mucous membrane of duodenum and distal ileum in patients with EMDD and irritable bowel syndrome (IBS).
 Materials and methods. The study includes 12 patients with EMDD, 16 patients with IBS and 12 relatively healthy persons (control group). Study design included analysis of food tolerance and evaluation of activity of sucrase, glucoamylase, maltase and lactase in mucous membrane of duodenum and ileum based on the method of Dahlquist with N.I. Belostotsky modification. Microsoft Office Excel and Statistica 10.0 were used for statistical evaluation of material. Mann–Whitney criterion was used to evaluate the differences between quantitative parameters. The differences were considered to be significant at p0.05. Control group was used for comparison.
 Results. In control group the carbohydrases activity in duodenum mucosa was not significantly statistically different from the one in IM. In patients of the IBS group, the activity of glucoamylase and maltase in the IM was significantly higher than in the duodenum: glucoamylase by 2.2 times, maltase by 2 times. In patients with EMDD the activity of glucoamylase, maltase and sucrase in IM is higher than in DM by 5.2, 3.8 and 2 times respectively, which signifies the formation of compensatory reaction of adaptive shift, initially described by A.M. Ugolev in 1985.
 Conclusion. The evaluation of carbohydrase activity in IM provides more information about pathogenesis of EMDD and its differential diagnosis with IBS.

Versatility of copper-iron bimetallic nanoparticles fabricated using Hibiscus rosa-sinensis flower phytochemicals: various enzymes inhibition, antibiofilm effect, chromium reduction and dyes removal.

Bimetallic nanoparticles (NPs) are considered superior in terms of stability and function with respect to its monometallic counterparts. Hence, in the present study Hibiscus rosa-sinensis flower extract was used to synthesis copper-iron bimetallic nanoparticles (HF-FCNPs). HF-FCNPs was characterized and its applications (biological and environmental) were determined. HF-FCNPs were spherical in shape with high percentage of copper inducted into the NPs. HF-FCNPs inhibited mammalian glucosidases [maltase (IC50: 548.71 ± 61.01µg/mL), sucrase (IC50: 441.34 ± 36.03µg/mL), isomaltase (IC50: 466.37 ± 27.09µg/mL) and glucoamylase (IC50: 403.12 ± 14.03µg/mL)], alpha-amylase (IC50: 16.27 ± 1.73µg/mL) and acetylcholinesterase [AChE (IC50: 0.032 ± 0.004µg/mL)] activities. HF-FCNPs showed competitive inhibition against AChE, maltase and sucrase activities; mixed inhibition against isomaltase and glucoamylase activities; whereas non-competitive inhibition against α-amylase activity. HF-FCNPs showed zone of inhibition of 16 ± 2mm against S. mutans at 100µg/mL concentration. HF-FCNPs inhibited biofilm formation of dental pathogen, S. mutans. SEM and confocal microscopy analysis revealed the disruption of network formation and bacterial cell death induced by HF-FCNPs treatment on tooth model of S. mutans biofilm. HF-FCNPs efficiently removed hexavalent chromium in pH-independent manner and followed first order kinetics. Through Langmuir isotherm fit the qmax (maximum adsorption capacity) was determined to be 62.5mg/g. Further, HF-FCNPs removed both anionic and cationic dyes. Altogether, facile synthesis of HF-FCNPs was accomplished and its biological (enzyme inhibition and antibiofilm activity) and environmental (catalyst to remove pollutants) applications have been understood.

Investigation of the potential mechanisms of α-amylase and glucoamylase through ultrasound intensification

The aim of this study is to enhance the efficiency of enzymes, reduce operational costs, and increase production output. Experimental research shows that ultrasound positively impacted the activity of α-amylase and glucoamylase, with the peak α-amylase activity observed at 30 W for 5 min and the highest glucoamylase activity at 60 W for 3 min. Ultrasonication extended the optimal temperature of both enzymes, but had no effect on the optimal pH. According to the kinetic experiments, ultrasonic treatment could improve the catalytic efficiency of α-amylase and glucoamylase. Furthermore, the SDS-PAGE results revealed that ultrasound treatment did not alter the molecular weights of the enzymes and their primary structures; The circular dichroism and fluorescence spectroscopy analysis indicated the secondary structural components, especially the α-sheet and the tryptophan fluorescence intensity, were notably affected by ultrasound. The changes in the secondary and tertiary structure of α-amylase and glucoamylase suggest that ultrasonic treatment may enhance their activities. Our findings provide a theoretical basis for the efficient utilization of α-amylase and glucoamylase through understanding the enzyme structure changes after ultrasound.

Study on the Fermented Grain Characteristics and Volatile Flavor Substances during the Tuqu Fermentation of Hunan Light-Flavor Baijiu.

The present study employed Hunan local Tuqu for fermentation and investigated the physicochemical properties, microbial community composition, and volatile flavor compounds of the fermented grains, as well as the correlation between the physicochemical indicators and the microbial community. The findings reveal that the activities of α-amylase and glucoamylase were highest during the initial stages of the fermentation process. The acid protease activity increased to 30.6 U/g on the second day and then decreased. Cellulose and lipase activities both showed an increasing trend. The moisture content increased sharply to 73.41% and then remained relatively stable. The acidity was highest on the eighth day. Fifty genera of bacteria and twenty-two genera of fungi were detected. Lactobacillus was dominant among bacteria, and Saccharomyces was dominant among fungi. A correlation analysis showed that there were positive correlations between moisture, acidity, cellulose, lipase activities and Lactobacillus, and there were positive correlations between moisture content, acidity, cellulase activity, acidic protease activity and Saccharomyces. A total of 46 volatile flavor compounds were detected, of which 6 alcohols and 14 esters constituted the major portion, and 9 key flavor compounds with an ROAV > 1 were identified throughout the fermentation process. Isoamyl acetate had the highest ROAV and made the greatest contribution to the flavor.

Preparation of layer-assembled W/O/W-type microencapsulated beads and application in solid-state fermentation.

In this study, microcapsule beads-0-3-layers (M-0-3 indicates microencapsulated beads with 0, 1, 2, and 3 layers) were prepared, their properties were measured and characterized, and the effects of M-0-3 on solid-state fermentation were investigated. The results showed that in a liquid environment, the releasing glucoamylase activities of M-0-3 were 55.77%, 47.67%, 45.85%, and 42.87% in 360h, respectively. In the solid environment, the reducing sugar production efficiency of M-0-3 was 29.84%, 27.72%, 19.16%, and 15.93% in 15 days, respectively. Adding M-0-3 improved the alcohol and reduced sugar content while decreasing the residual starch content of the Jiupei, indicating that adding M-0-3 was beneficial to the solid-state fermentation of Baijiu. Solid-state fermentation simulation experiments illustrated that microcapsule beads play a positive role in the production of Baijiu, enhancing raw material utilization and yield of Baijiu production.

Inhibition mechanism of rice glutelin on extruded starch digestion: From the structural properties of starch and enzyme activity

To increase the anti-digestion ability of extruded rice starch (ERS), the influence of rice glutelin (RG) on digestive and structural characteristics of ERS were investigated. The resistant starch content increased from 4.49 % to 18.08 % as the RG content increased, while the digestion rate and digestion velocity constant were reduced by the incorporation of RG. Morphological observations showed that ERS was adhered and encapsulated by RG, and the specific area of starch granules were decreased after the addition of RG. The results of XRD and FTIR suggested that the long-range and short-range orders of ERS were improved due to the complexation with RG. The thickness of crystalline of ERS was increased while its amorphous region thickness was reduced by the supplementation with RG. The 1H NMR and 13C NMR data revealed that the branching degree and double helix content of ERS was increased by 46.24 % and 52.67 % when RG content reached to 12 %. Additionally, the addition of RG altered the molecular weight and chain length distribution of ERS. The α-amylase activity and glucoamylase activity was inhibited by RG. These results could provide a valuable basis for the application of RG in extruded rice starchy foods with lower glycemic index.

Exploring the interaction of phytochemicals from Hibiscus rosa-sinensis flowers with glucosidase and acetylcholinesterase: An integrated in vitro and in silico approach

Targeting multiple factors such as oxidative stress, alpha glucosidase and acetylcholinesterase (AChE) are considered advantageous for the treatment of diabetes and diabetes associated-cognitive dysfunction. In the present study, Hibiscus rosa-sinensis flowers anthocyanin-rich extract (HRA) was prepared. Phytochemical analysis of HRA using LC-ESI/MS/MS revealed the presence of various phenolic acids, flavonoids and anthocyanins. HRA showed in vitro antioxidant activity at low concentrations. HRA inhibited all the activities of mammalian glucosidases and AChE activity. The IC50 value of HRA for the inhibition of maltase, sucrase, isomaltase, glucoamylase and AChE was found to be 308.02 ± 34.25 µg/ml, 287.8 ± 19.49 µg/ml, 424.58 ± 34.75 µg/ml, 408.94 ± 64.82 µg/ml and 264.13 ± 30.84 µg/ml, respectively. Kinetic analysis revealed mixed-type inhibition against all the activities except for glucoamylase (competitive) activity. In silico analysis confirmed the interaction of two active constituents cyanidin 3-sophoroside (CS) and quercetin 3-O-sophoroside (QS) with four subunits, n-terminal and c-terminal subunits of human maltase-glucoamylase and sucrase-isomaltase as well as with AChE. Molecular dynamics simulation, binding free energy calculation, DCCM, PCA, PCA-based free energy surface analysis ascertained the stable binding of CS and QS with target proteins studied. HRA could be used as complementary therapy for diabetes and cognitive improvement.

327 A Novel, in Vivo Model to Increase Endogenous Pancreatic and Small Intestinal Carbohydrase Activity to Evaluate Limitations of Small Intestinal Starch Digestion in Cattle

Abstract Consumption of high-grain diets by cattle can result in large quantities of starch that flow to the small intestine for potential enzymatic digestion. However, small intestinal starch digestion is potentially limited because of insufficient activity of pancreatic and/or small intestinal carbohydrases. Studies suggest regulation of carbohydrase activity is complex in cattle and perhaps uncoordinated in response to luminal carbohydrate flow. The objective of this experiment was to use postruminal casein infusion and exogenous glucagon-like peptide 2 (GLP-2) administration, known stimulators of pancreatic and small intestinal function, to evaluate their effects on pancreatic and small intestinal carbohydrase activities. Twenty-four Holstein steers [250 ± 23 kg body weight (BW)] were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. Steers were fed an alfalfa cube-based diet to limit dietary starch intake. Steers received a continuous abomasal infusion of 4 g/kg of BW of raw corn starch combined with either 0 or 1.33 g/kg of BW of casein for 7 d. Steers received subcutaneous injections in two portions daily of excipient (0.5% bovine serum albumin) or 100 µg/kg of BW GLP-2. This resulted in four treatments: control, casein, GLP-2, and casein + GLP-2. At the end of the 7-d treatment period, steers were slaughtered for pancreatic and small intestinal tissue collection. Data were analyzed using the GLM procedure of SAS. Postruminal casein infusion increased (P ≤ 0.03) pancreatic mass by 12.6%, total pancreatic α-amylase activity by 50%, and postruminal starch disappearance from 96.7% to 99.3%. Exogenous GLP-2 increased (P < 0.01) total small intestinal mass and small intestinal mucosal mass by 1.2 kg and 896 g, respectively. Relative to control, GLP-2 and casein + GLP-2 treatments increased (P = 0.04) total small intestinal α-glucosidase activity (sum of maltase, isomaltase, glucoamylase) by 83.5%. Total small intestinal maltase, isomaltase, and glucoamylase activity was 90%, 100%, and 66.7% greater for GLP-2 and casein + GLP-2 steers compared with control. The use of postruminal casein infusion and exogenous GLP-2 administration resulted in four distinct carbohydrase activity phenotypes. Relative to control, casein increased pancreatic α-amylase activity, GLP-2 increased small intestinal α-glucosidase activity, and the combination of casein and GLP-2 increased both pancreatic α-amylase activity and small intestinal α-glucosidase activity. This approach provides a novel in vivo animal model to selectively increase endogenous carbohydrase activity to overcome complications of coordinating carbohydrase activity with luminal nutrient flows. This model could be useful to understand physiological mechanisms that might improve small intestinal starch assimilation and efficiency of cattle consuming high-grain diets.

Preparation of glucoamylase microcapsule beads and application in solid-state fermentation.

Baijiu brewing adopts the solid-state fermentation method, using starchy raw materials, Jiuqu as saccharifying fermenting agent, and distilled spirits made by digestion, saccharification, fermentation and distillation. In the late stages of solid-state fermentation of Baijiu, the reduced activity of glucoamylase leads to higher residual starch content in the Jiupei, which affects the liquor yield. The direct addition of exogenous glucoamylase leads to problems such as the temperature of the fermentation environment rising too quickly, seriously affecting the growth of microorganisms. To solve the problem of reduced activity of glucoamylase in the late stage of solid-state fermentation of Baijiu, microcapsule beads (M-B) based on microcapsule emulsion were prepared and the effect of M-B on solid-state fermentation of Baijiu was investigated. The results showed that the release of M-B before and after drying was 53.27% and 25.77% in the liquid state (120 h) and 29.84% and 22.62% in the solid state (15 days), respectively. Adding M-B improved the alcohol by 0.33 %vol and reducing sugar content by 0.51%, reduced the residual starch content by 1.21% of the Jiupei, and had an insignificant effect on the moisture and acidity of the Jiupei. M-B have excellent sustained-release properties. The addition of M-B in solid-state fermentation significantly increased the alcohol content, reduced the residual starch content of Jiupei, ultimately improving the starch utilization rate and liquor yield of Baijiu brewing. The preparation of M-B provides methods and approaches for applying other active substances and microorganisms in the brewing of Baijiu. © 2023 Society of Chemical Industry.

Effect of pulsed electric field on spore germination rate and enzyme activity of Aspergillus niger

Pulsed electric field (PEF) treatment on Aspergillus niger, which is an important source of several enzymes, was conducted to investigate the effects of different PEF parameters on spore germination of A. niger and the production of lipase and glucoamylase. The results showed that the spore germination rate and the relative activities of lipase and glucoamylase could be promoted when the electric field strength was in the range of 5– 15 kV/cm and the treatment time was in the range of 1– 7.5 ms. During the processing, the concentration of spores was maintained within a range of approximately 3.5 × 106 CFU/mL. Maximum increase of spore germination rate, lipase and glucoamylase activities were 217%, 25.6% and 31.3% respectively, which were observed when the spore suspension was subjected to PEF treatment with 10 kV/cm field strength for 5 ms. Lipase activity was inhibited with the increase of field strength and treatment time. Further analysis of the input energy density during PEF showed that the spore germination rate and the relative activities of enzymes were also promoted and then inhibited with increasing input energy density, but the electric field strength was more decisive. Industrial relevancePEF is an emerging non-thermal microbial treatment technology with the characteristics of short treatment time and low energy consumption. Aspergillus niger is an important microbial species in the food industry, as the enzymes it produces play an important role in various fields. This study applied PEF technology to A. niger and significantly promoted the germination of its spores, and the activity of its lipase and glucoamylase, which suggests PEF technology has the potential to be used to shorten the industrial production cycle of A. niger and its enzyme products.

Biovalorisation of mixed food waste through newly isolated thermo tolerant fungal cell factories: A step toward transforming waste to wealth

Food waste is a lucrative biomass consisting of abundant complex organic content that can be reduced to simpler compounds and channelled towards bio-manufacturing. In this study, the hydrolysis potential of mixed food and synthetic food waste from the newly isolated fungal enzymes was examined. The screening and characterization of fungal strains with higher starch and protein degrading ability were executed. Among the isolated strains, Aspergillus terreus exhibited a better glucoamylase enzyme production rate (89 ± 4.50 U/g). The random mutagenesis of A. terreus with 150 mM EMS enhanced its glucoamylase activity by 20% as compared with the wild-type strain. The enzyme displayed its optimum activity at 55 °C, pH 5.0 with 20 min of incubation time. Metal ions such as Mn+2 and Ca+2 at 2 mM concentration upregulated the glucoamylase activity and further at 5 mM of Mn+2 concentrations the enzyme activity was augmented by about 53% enhancement as equalled with control. Strain incubation temperature had tremendous impacts on the glucoamylase activity, showing the highest activity of 193.02 ± 6.89 (U/g) and 100.03 ± 4.67 (U/g) in SFW and MFW, respectively at 37 °C under solid state fermentation. In the later stage, the food waste hydrolysis rate was improved by adapting statistical tools such as Box-Behnken design (BBD). An optimum glucose release of 0.43 (g/g) was achieved by BBD. The artificial neural network linked genetic algorithm (ANN-GA) elevated the glucose concentration further to 0.57 (g/g). The mutated strain finally produced glucose of 0.57 g/g, free amino nitrogen of 185 mg/L and 195 mg/L of inorganic phosphate. To the best of our knowledge, this is the first study, where mixed food waste is hydrolysed efficiently using A. terreus. The attained hydrolysate can be further advanced towards integrated biorefinery.

Effect of Peony (Paeonia ostii) Seed Meal Supplement on Enzyme Activities and Flavor Compounds of Chinese Traditional Soybean Paste during Fermentation.

Peony seed meal (PSM) is the by-product obtained from peony seeds after oil extraction. In this study, PSM was incorporated into traditional koji-making, and its impacts on koji enzyme activities and flavor compounds in final products were investigated. In the process of koji fermentation, the optimal addition ratio of PSM to soybean was determined as 7:3. Under this ratio, the maximum enzyme activities of neutral protease, amylase, and glucoamylase were 1177.85, 686.58, and 1564.36 U/g, respectively, and the koji obtained was subjected to maturation. During post-fermentation, changes in the fermentation characteristics of the paste samples were monitored, and it was found that compared to the soybean paste without PSM, the enzyme activities maintained at a relatively good level. The PSM soybean paste contained a total of 80 flavor compounds and 11 key flavor compounds (OAV ≥ 1), including ethyl isovalerate, isovaleric acid, hexanal, phenylacetaldehyde, 3-Methyl-1-butanol 4-heptanone, 2-pentylfuran, methanethiol ester caproate, isoamyl acetate, 3-methyl-4-heptanone, and isovaleraldehyde. These findings could be used to improve the quality of traditional fermented paste, enrich its flavor, and simultaneously promote PSM as a valuable resource for fermented foods.

Postruminal Casein Infusion and Exogenous Glucagon-Like Peptide 2 Administration Differentially Stimulate Pancreatic α-Amylase and Small Intestinal α-Glucosidase Activity in Cattle

BackgroundIncreasing luminal carbohydrate flow decreases pancreatic α-amylase activity but can increase jejunal maltase activity, suggesting that regulation of carbohydrase activity is perhaps uncoordinated in response to luminal carbohydrate flow. Increasing luminal casein flow increases pancreatic α-amylase activity in cattle, and exogenous glucagon-like peptide 2 (GLP-2) has been shown to increase small intestinal α-glucosidase activity in nonruminants. ObjectivesThe objective was to evaluate the effects of postruminal casein infusion, exogenous GLP-2, or their combination on endogenous pancreatic and small intestinal carbohydrase activity in cattle postruminally infused with starch. MethodsHolstein steers [n = 24; 250 ± 23 kg body weight (BW)] received a continuous abomasal infusion of 3.94 g raw corn starch/kg of BW combined with either 0 or 1.30 g casein/kg of BW. Steers received subcutaneous injections in 2 equal portions daily of excipient (0.5% bovine serum albumin) or 100 μg GLP-2/kg of BW per day. At the end of the 7-d treatment period, steers were slaughtered for tissue collection. Data were analyzed using the MIXED procedure of SAS version 9.4 (SAS Institute Inc.). ResultsPostruminal casein infusion increased (P ≤ 0.03) pancreatic mass by 12.6%, total pancreatic α-amylase activity by 50%, and postruminal starch disappearance from 96.7% to 99.3%. Exogenous GLP-2 increased (P < 0.01) total small intestinal and mucosal mass by 1.2 kg and 896 g, respectively. Relative to control, GLP-2 and casein + GLP-2 increased (P = 0.04) total small intestinal α-glucosidase activity by 83.5%. Total small intestinal maltase, isomaltase, and glucoamylase activity was 90%, 100%, and 66.7% greater for GLP-2 and casein + GLP-2 steers compared with control. ConclusionsCasein increased pancreatic α-amylase activity, GLP-2 increased small intestinal α-glucosidase activity, and the combination of casein and GLP-2 increased both pancreatic α-amylase activity and small intestinal α-glucosidase activity. This novel approach provides an in vivo model to evaluate effects of increasing endogenous carbohydrase activity on small intestinal starch digestion.

상업용 효소제를 이용한 무증자 쌀 발효 증류식 소주의 제조 가능성

The production of distilled soju by fermenting nonsteamed rice was evaluated using commercial enzyme products. White koji and modified nuruk had alpha-amylase activities of 31.90 U/g and 3,532.71 U/g, respectively, and gluco-amylase activities of 698.32 U/g and 4,899.58 U/g, respectively. The enzyme products had activities of 5,604.15-225,182.00 U/g and 13,517.41-120,822.41 U/g, respectively. At enzyme concentrations of &gt;800 mg/L, the Chung-moo-purified enzyme had an alcohol productivity of ≥19%. Nurukzyme R400, Sanferm Yied, and Diazyme X4 exhibited alcohol productivities of &gt;19% at concentrations of &gt;600 mg/L. The alcohol content of the vacuum distillates was 41.31%-44.86%. The volatile component with the alcohol content adjusted to 25% was analyzed and principal component analysis was performed. The volatile components in white koji, Diazyme X4, and Sanferm Yield were similar. The modified nuruk treatment group had a relatively high ethyl lactate content compared to the white koji treatment group. The Nurukzyme R400 treatment group had high contents of butyric acid and ethyl butyrate. The Chung-moo-purified enzyme was characterized by a low component content. Thus, when enzyme products were used in nonsteamed rice fermentation, no effect on the alcohol productivity and quality of vacuum distilled soju was observed, suggesting that it can replace white koji and modified nuruk.

Особенности пищевых интолерантностей у больных с синдромом раздраженного кишечника

The aim was to evaluate the activity of intestinal carbohydrases in patients with irritable bowel syndrome (IBS) with symptoms of food intolerance. Material and methods. 126 patients with IBS (83 women and 43 men, median age – 32.0 years (Q1–Q3: 27–38 years)) were examined. The diagnosis of IBS was established on the basis of Roman Criteria IV. A questionnaire was conducted for all patients to identify food intolerances, according to the results of which the patients were divided into three groups: the first – patients with isolated intolerance to foods with a high content of FODMAP; the second – patients with isolated intolerance to milk and dairy products; the third – patients with combined intolerance. To determine the activity of intestinal carbohydrates: lactase, sucrose, maltase and glucoamylase, all patients underwent esophagogastroduodenoscopy with biopsy samples from the duodenum. The activity of carbohydrases was determined by the Dahlquist method in the modification of N.I. Belostotsky. The control group consisted of 30 conditionally healthy people (10 men and 20 women, median age – 33.9 years (Q1–Q3: 24–35)), comparable in age and gender with patients with IBS. The activity of intestinal enzymes in this group was within the reference values. Statistical data processing was carried out using the computer program Statistica 8.0. Results. According to the results of the survey, it was found that out of 126 patients with IBS, 52 (41.3%) patients believed that they had food intolerance to certain foods. Isolated intolerance to foods with a high content of FODMAP was noted by 13 (10.3%) patients, 16 (12.7%) patients believed that they had isolated intolerance to milk and dairy products, and 23 (18.3%) patients indicated combined intolerance. In patients with IBS and isolated intolerance to foods high in FODMAP, the median activity of glucoamylase was 120.0 (68.5–209.2) ng/mg of glucose per 1 mg of tissue per minute (ng/mg × min), maltase – 630.5 (480.7–951.0) ng/mg × min, sucrose – 50.0 (32.8–68.8) ng/mg × min, lactase – 10.5 (5.5–40.5) ng/mg × min. Comparing the activity of carbohydrases with the control group revealed the statistically significant difference (p &lt; 0.05) for each enzyme studied.In the group of patients with IBS and isolated intolerance to milk and dairy products, the median activity of all the intestinal enzymes studied was also lower than that in the control group: the activity of glucoamylase was 107.0 (64.0–174.0) ng/mg × min, maltase – 622.0 (481.5–887.0) ng/mg × min, sucrose – 48.0 (35.5-60.0) ng/mg × min, lactase – 8.0 (3.0–22.5) ng/mg × min. Among patients with IBS and the presence of combined intolerance to foods (with a high content of FODMAP and dairy products), the median activity of all enzymes significantly differed from the control group (p &lt; 0.05). The activity of glucoamylase was 107.5 (57.5–194.2) ng/mg × min, maltase – 627.0 (480.7–911.7) ng/mg × min, sucrose - 47.5(34.8–61.5) ng/mg × min, lactase - 9.0 (4.0–28.8) ng/mg × min. Conclusion. Food intolerance was noted in 52 (41.3%) patients with IBS. Among the patients who noted the presence of all the studied food intolerances (isolated or combined intolerance to milk and dairy products, as well as products with a high content of FODMAP), a significant decrease in the activity of intestinal enzymes (glucoamylase, lactase, sucrose and maltase) was found compared with the control (p &lt; 0.05), which may indicate the presence of they have disaccharidase deficiency

Immobilized glucoamylase based on ZIF-8: Preparation, response surface optimization, characterization.

The glucoamylase@ZIF-8 was prepared using ZIF-8 material as the carrier in this study. The preparation process was optimized by response surface methodology, and the stability of glucoamylase@ZIF-8 was determined. The material was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the optimum preparation process of glucoamylase@ZIF-8 was 1.65mol 2-methylimidazole, 5.85mL glucoamylase, 33°C stirring temperature, 90min stirring time, and 84.0230%±0.6006% embedding rate. At 100°C, the free glucoamylase completely lost its activity, whereas the glucoamylase@ZIF-8 still had a retained enzyme activity of 12.0123%±0.86158%; at pH 3-6, the highest activity of glucoamylase@ZIF-8 was 95.9531%±0.96181%, and about 80% of glucoamylase activity could be retained under alkaline conditions. When the ethanol concentration was 13%, the retained enzyme activity was 7.9316%±0.19805%, significantly higher than free enzymes. The Km of glucoamylase@ZIF-8 and free enzyme were 1235.6825 and 80.317mg/mL, respectively. Vmax was 0.2453 and 0.149mg/(mLmin), respectively. The appearance, crystal strength, and thermal stability of glucoamylase@ZIF-8 were improved after optimization, and they had high reusability.

The effect of the FODMAP and rebamipid diet on the activity of disaccharidases in patients with enteropathy with impaired membrane digestion

To compare the effect of a diet low in fermentable oligo-, di-, monosaccharides and polyols (fermentable oligosaccharides, disaccharides, monosaccharides and polyols - FODMAP) and rebamipide on carbohydrate tolerance and disaccharidases activity in patients with maldigestive enteropathy (ENMP). The study included 61 patients with ENMP with reduced small intestine carbohydrases. Their glucoamylase activity was 100 ng glucose/mg tissue × min (quartile 53, 72), maltase - 504 (quartile 258, 708), sucrase - 43 (quartile 25, 58), lactase - 8 (quartile 4, 20). Group 1 included 19 people on a low FODMAP diet. The 2nd group included 42 patients who were on a normal diet and received rebamipide 300 mg/day. Patients were monitored weekly for 8 weeks. In 16 patients of the 1st group, abdominal pain and stool disorders decreased, in 15 patients, swelling and rumbling in the abdomen stopped. Glucoamylase activity increased to 196 (quartile 133, 446, р<0.024) ng glucose/mg tissue × min, maltase activity increased to 889 (quartile 554, 1555, p<0.145), sucrase activity increased to 67 (quartile 43, 175, p<0.039), lactase activity increased to 13 (quartile 9, 21, p<0.02). After the diet was discontinued, intestinal symptoms in patients of group 1 resumed. In 27 patients of the 2nd group after 4 weeks dyspeptic manifestations decreased, in 34 patients the tolerability of products containing FODMAP improved. Continuation of treatment up to 8 weeks contributed to a further improvement in well-being. Glucoamylase activity increased after 4 and 8 weeks to 189 (quartile 107, 357, p<0.013) and 203 (quartile 160, 536, p<0.005), respectively; maltase - up to 812 (quartile 487, 915, p<0.005) and 966 (quartile 621, 2195, р<0.0012); sucrases - up to 60 (quartile 34, 105, p<0.013) and 75 (quartile 52, 245, р=0.003); lactase - up to 12 (quartile 8, 12, p<0.132) and 15 ng glucose/mg tissue ×min (quartile 10, 20, р<0.092). The clinical symptoms of fermentable carbohydrate intolerance and increased membrane enzyme activity are reduced by a low FODMAP diet in patients with ENMT, but clinical symptoms of food intolerance reappear when switching to a normal diet. Treatment with rebamipide improves food tolerance and consistently increases the activity of TSOTS enzymes after 4 and 8 weeks.