Α-amylase Activity Research Articles

The rice cultivar affects the population growth and physiological enzyme activity of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) reared on rice grains

The rice weevil, Sitophilus oryzae, is an important pest of stored rice that causes substantial post-harvest losses. In this study, the population growth and physiological enzyme activity of S. oryzae reared on grains from five rice cultivars, red brown rice (RBR), Daohuaxiangmi (DHXM), Baishuigongmi (BSGM), Yashuixinmi (YSXM), and white glutinous rice (WGR), were studied. The duration of the immature stages of S. oryzae was shortest when reared on RBR (29.74 d) and longest when reared on YSXM (34.34 d). When reared continuously on grains of each cultivar for multiple generations for a period of 5 consecutive months, the average growth rate of the S. oryzae population was the highest in RBR (384.38%), followed by BSGM (98.35%) and WGR (82.02%), whereas in DHXM (−24.38%) and YSXM (−27.12%) a negative population growth was observed. The catalase and superoxide dismutase activities were significantly higher in S. oryzae fed on YSXM than on the other cultivars, whereas peroxidase activity took its highest value for S. oryzae fed on BSGM and lowest when fed on YSXM, WGR or RBR. The activities of three detoxification enzymes were highest in S. oryzae reared on YSXM, while glutathione transferase and carboxylesterase activities were lowest when fed on RBR. Activities of the digestive enzymes α-amylase, cellulase, and lipase were lowest in S. oryzae reared on YSXM and highest when fed on RBR. Pepsin activity was highest in S. oryzae reared on YSXM, with no significant difference to that on RBR. Our results suggest that the significant impact of the rice cultivar on the population growth of S. oryzae may be associated with physiological enzyme activities, which play an important role in the nutrient and detoxification metabolism and growth of insects.

Influence of the cooking system, chemical composition, and α-amylase activity on the sensory profile of chestnut cultivars - longal and judia - and their consequence on consumer's acceptability

The chestnut (Castanea sativa Mill) is a nut with single nutritional and sensory properties that play an essential role in human nutrition, especially in celiac patients, where it is highly recommended for that diet. This study aims to understand the influence of the chestnut cooking process, chemical composition, and tasters α-amylase activity on the sensory profile of Castanea sativa Mill chestnut cultivars. - Longal and Judia - and their consequence on consumer acceptance. The methodology focuses on enzymatic kits for measuring α-amylase enzyme activity, quantifying crude protein, starch, and crude fat by analytical methods, and evaluating consumer perception through sensory descriptive tests.After analysis of the chemical composition, it was possible to verify that chestnuts of both cultivars have a high starch concentration, influencing the taster's α-amylase activity, and at the same time, are low in sugar and fat. These characteristics make chestnuts a high-energy food. The results also showed chemical correlations between the amount of starch and soluble sugars and crude fat and protein content. In addition, the analysis of the CATA test (Check-All-That-Apply), applied to consumers, and a QDA test (Quantitative Descriptive Analysis), applied to a trained tasting panel, denoted that roasted Judia and Longal are chestnuts with sensory attributes highly appreciated. Moreover, the higher α-amylase activity detected when tasting chestnuts from the Judia cultivar may not necessarily result in a sweeter or more dissoluble chestnut.

Exploring the Multifaceted Potential of a Peptide Fraction Derived from Saccharomyces cerevisiae Metabolism: Antimicrobial, Antioxidant, Antidiabetic, and Anti-Inflammatory Properties.

The rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction's cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through α-amylase and α-glucosidase inhibitory assays. The results demonstrate that the 2-10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 ± 32.5 µM TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNFα gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes α-amylase (IC50 of 199.3 ± 0.9 µg/mL) and α-glucosidase (IC20 of 270.6 ± 6.0 µg/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides.

Insight into biological activities of chemically characterized extract from Marrubium vulgare L. in vitro, in vivo and in silico approaches.

Aqueous extracts of Marrubium vulgare L. (M. vulgare) are widely used in traditional medicine for their therapeutic effects. Hence, this study aims to evaluate in vitro, in vivo, and in silico the biological activities of M. vulgare aqueous extract to further support their traditional use. Qualitative phytochemical tests of M. vulgare extracts showed the presence of primary and secondary metabolites, while quantitative analyses recorded revealed the contents of total phenols, flavonoids, and tannins, with values of 488.432 ± 7.825mg/EAG gallic acid extract/g, 25.5326 ± 1.317mg/EQ Quercetin extract/g and 23.966 ± 0.187mg/EC catechin extract/g, respectively. Characterization of the phytochemical constituents of the extract revealed the presence of catechin and maleic acid as the most abundant while the evaluation of the antioxidant power revealed that the extract possesses significant antioxidant capacity, antimitotic potential, and antimicrobial properties against Streptococcus agalactiae and Staphylococcus epidermidis among many others. The antidiabetic activity of the extract showed a potent antihyperglycemic effect and a significant modulation of the pancreatic α-amylase activity as revealed by both in vitro and in vivo analysis, while an in silico evaluation showed that chemicals in the studied extract exhibited the aforementioned activities by targeting 1XO2 antimitotic protein, W93 antidiabetic protein and 1AJ6 antimicrobial protein, which revealed them as worthy of exploration in drug discovery odyssey. Conclusively, the result of this study demonstrates the numerous biological activities of M. vulgare and gives credence to their folkloric and traditional usage.

HYPOGLYCEMIC POTENTIAL OF HIBISCUS ROSA-SINENSIS AND MANGIFERA INDICA LEAVES BY IN VITRO METHODS

Objective: The objective of the present study was to provide in vitro evidence for the potential inhibitory activity of extracts of Mangifera indica (MI) and Hibiscus rosa-sinensis on α-amylase and α-glucosidase enzymes. Methods: The plant extracts were prepared with methanol by maceration. Different concentrations (10, 20, 40, 80, and 100 μg/mL) of both the extracts were made using distilled water, and the extracts were subjected to α-amylase and α-glucosidase inhibitory assay. The absorbance was measured at 540 nm and 405 nm using spectrophotometer. Using this method, the percentage of α-amylase and α-glucosidase inhibitory activity and IC50 values of each extract were calculated. Results: The methanolic extracts of MI and H. rosa-sinensis exhibited significant α-amylase and α-glucosidase inhibitory activity. The inhibitory effect of α-amylase inhibitory assay was observed up to 89% and 90% at a concentration of 100 μg/mL in MI and H. rosa-sinensis, respectively. The inhibitory effect of α-glucosidase inhibitory assay was observed up to 89% and 91% at a concentration of 100 μg/mL in MI and H. rosa-sinensis, respectively, and is comparable to the standard acarbose (94% at 100 μg/mL). The IC50 values of α-amylase inhibitory assay of MI and H. rosa-sinensis are 35.33 and 30.97, respectively. The IC50 values of α-glucosidase inhibitory assay of MI and H. rosa-sinensis are 31.67 and 25.86, respectively. The IC50 value of acarbose is 6.94. Conclusion: The results obtained support that MI and H. rosa-sinensis extracts exhibit considerable α-amylase and α-glucosidase inhibitory activity which can be attributed to the phytochemical constituents present in them. Further, this study supports its usage in ethno medicines for the management of diabetes.

In Vitro Inhibition of α-Amylase, α-Glucosidase and Antioxidant Activity of Milk Containing Fenugreek Seed Alcoholic Extract.

The aim of this study was to evaluate the effect of fenugreek seed alcoholic extract (FSAE) at the levels of 0.15% and 0.30% (V/V) on the selected properties of enriched milk during the 10-day storage period at 4°C. The results demonstrated that with the addition of FSAE, the pH, brightness intensity and white color coefficient decreased and the values of acidity, viscosity, a* and b* indexes, total phenol content (TPC), total flavonoid content (TFC), antioxidant activity (AA) and enzyme inhibitory activity of enriched milk samples increased significantly compared to the control (p < 0.05). During the storage period, a decrease in TPC, TFC, AA and inhibitory activity was observed in all samples (p < 0.05). The FSAE was able to significantly reduce total microbial count (TMC) in milk samples (p < 0.05). In terms of sensory characteristics, the best sensory scores during the storage period were related to the sample containing 0.15% (V/V) FSAE. Overall, a positive and direct relationship was found between the beneficial effects of FSAE and its concentration. Finally, according to the results of the overall acceptance score in sensory tests, the sample containing 0.15% (V/V) FSAE was introduced as the best sample.

Mechanistic study on the inhibition of α-amylase and α-glucosidase using the extract of ultrasound-treated coffee leaves.

Our previous studies have shown that ultrasound-treated γ-aminobutyric acid (GABA)-rich coffee leaves have higher antioxidant and angiotensin I converting enzyme inhibitory activity. However, whether they have antidiabetic activity remains unknown. In this study, we aimed to investigate the inhibitory activities of coffee leaf extracts prepared with (CLE-U) or without (CLE-NU) ultrasound pre-treatment on α-amylase and α-glucosidase. Subsequently, we evaluated the binding interaction between CLE-U and both enzymes using multi-spectroscopic and in silico analyses. Ultrasound pre-treatment increased the inhibitory activities of CLE-U against α-amylase and α-glucosidase by 21.78% and 25.13%, respectively. CLE-U reversibly inhibit both enzymes, with competitive inhibition observed for α-amylase and non-competitive inhibition for α-glucosidase. The static quenching of CLE-U against both enzymes was primarily driven by hydrogen bond and van der Waals interactions. The α-helical of α-amylase and α-glucosidase was increased by 1.8% and 21.3%, respectively. Molecular docking results showed that the key differential compounds, including mangiferin, 5-caffeoylquinic acid, rutin, trigonelline, GABA, caffeine, glutamate et al. present in coffee leaves, interacted with specific amino acid residues located at the active site of α-amylase (ASP197, GLU233, and ASP300). The binding of α-glucosidase and these bioactive components involved amino acid residues, such as PHE1289, PRO1329, and GLU1397 located outside the active site. Ultrasound-treated coffee leaves are potential anti-diabetic substances, capable of preventing diabetes by inhibiting the activities of α-amylase and α-glucosidase, thus delaying starch digestion. Our study provides valuable information to elucidate the possible anti-diabetic capacity of coffee leaves through the inhibition of α-amylase and α-glucosidase activities. This article is protected by copyright. All rights reserved.

Biochemical and Phylogenetic Analysis of Italian Phaseolus vulgaris Cultivars as Sources of α-Amylase and α-Glucosidase Inhibitors.

Phaseolus vulgaris α-amylase inhibitor (α-AI) is a protein that has recently gained commercial interest, as it inhibits mammalian α-amylase activity, reducing the absorption of dietary carbohydrates. Numerous studies have reported the efficacy of preparations based on this protein on the control of glycaemic peaks in type-2 diabetes patients and in overweight subjects. A positive influence on microbiota regulation has also been described. In this work, ten insufficiently studied Italian P. vulgaris cultivars were screened for α-amylase- and α-glucosidase-inhibiting activity, as well as for the absence of antinutritional compounds, such as phytohemagglutinin (PHA). All the cultivars presented α-glucosidase-inhibitor activity, while α-AI was missing in two of them. Only the Nieddone cultivar (ACC177) had no haemagglutination activity. In addition, the partial nucleotide sequence of the α-AI gene was identified with the degenerate hybrid oligonucleotide primer (CODEHOP) strategy to identify genetic variability, possibly linked to functional α-AI differences, expression of the α-AI gene, and phylogenetic relationships. Molecular studies showed that α-AI was expressed in all the cultivars, and a close similarity between the Pisu Grogu and Fasolu cultivars' α-AI and α-AI-4 isoform emerged from the comparison of the partially reconstructed primary structures. Moreover, mechanistic models revealed the interaction network that connects α-AI with the α-amylase enzyme characterized by two interaction hotspots (Asp38 and Tyr186), providing some insights for the analysis of the α-AI primary structure from the different cultivars, particularly regarding the structure-activity relationship. This study can broaden the knowledge about this class of proteins, fuelling the valorisation of Italian agronomic biodiversity through the development of commercial preparations from legume cultivars.

Nutritional and Antioxidant Properties of Resistant Starch-Based Flour Blends from Unripe Plantain, Pigeon Pea and Rice-Bran

Aim: The nutrients and antioxidants of blends of native resistant starch, acetylated resistant starch, and flours of unripe plantain, pigeon pea and rice bran were investigated as possible alternatives to functional food products in managing type-2 diabetes.&#x0D; Place and Duration of Study: Food Chemistry Laboratory, Department of Food Science and Technology, and Functional Foods Laboratory, Department of Biochemistry, Federal University of Technology, Akure, Nigeria. From January, 2022 to January, 2023.&#x0D; Methodology: Native resistant starch was isolated from plantain and was modified via acetylation. Five sample blends of native resistant starch, acetylated resistant starch, and flours of pigeon pea and rice bran were prepared, using Mixture Design Expert 11.0.0 and were coded as follows: PLF – (100% Plantain flour), used as a control sample; PLPRF – plantain flour: pigeon pea flour: rice bran flour (73.08:15.15:11.76); PSPRF – native plantain starch: pigeon pea flour: rice bran flour (73.08:15.15:11.76); AP1SPRF – acetylated plantain starch: pigeon pea flour: rice bran flour (73.08:15.15:11.76); AP2SPRF – acetylated plantain starch: pigeon pea flour: rice bran flour (70.67:18.15:11.18). The proximate compositions, minerals, amino acid profiles, α-amylase and α-glucosidase and in-vitro antioxidant potentials of the samples were compared with the commercial flour product, CRF (100% Cerolina flour: wheat and soybean produced by More Foods Lagos, Nigeria).&#x0D; Results: The results showed that AP2SPR had the lowest moisture content (2.40%), highest ash content (4.63%) and lowest fat content (2.42%). K, Cu, Fe. Na, Zn and P were more relatively abundant in the blends than in PLF. Generally, the chemical compositions of the flour blends improved with the addition of quality protein, which extensively enhanced the mineral contents in terms of Ca, K, Fe, Zn and P. Total essential amino acids were higher in PLF and the flour blends than CRF, ranging from 35.18 (g/100g protein) in CRF to 41.81 (g/100g protein) in PLPRF whereas their total non-essential amino acids showed an opposite trend, ranging from 58.18 (g/100g protein) in PLPRF to 64.84 (g/100g protein) in CRF. Upon acetylation, total essential amino acids improved from 39.84 (g/100g protein) in PSPRF to 41.00 (g/100g protein) in AP1SPRF and 41.32 (g/100g protein) in AP2SPRF. Both AP1SPRF and AP2SPRF were able to reduce Fe2+ to Fe3+, scavenge DPPH, FRAP and ABTS and inhibit α-amylase and α-glucosidase activities.&#x0D; Conclusion: The flour blends of AP1SPRF and AP2SPRF studied were a good source of resistant starch and bioactive ingredients that would be useful in a variety of dietary functional food products to manage type-2 diabetes.

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.

Antioxidant, α-amylase and α-glucosidase Inhibitory Activities of Aqueous and Methanolic Extracts From Athamanta sicula L.

Introduction: Oxidative stress plays a major role in developing diabetes complications; therefore, it is possible to use natural antioxidants as therapeutic agents for diabetes. Aims: This study aimed to find an important source of phenolics from Athamanta sicula L. (A. sicula) and confirm that this plant could be a significant source of medically important natural compounds by confirming its antioxidant, α-amylase and α-glucosidase inhibitory potential. Methods: Antioxidant property was performed using 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, metal chelating, and cupric reducing antioxidant capacity methods. The α-amylase and α- glucosidase inhibitory activities were investigated using an in vitro model. Moreover, polyphenols and flavonoid contents of the tested extracts were carried out. Results: The methanolic extract exhibited the highest phenolic and flavonoid content compared to the aqueous extract. However, aqueous extract possessed the strongest antioxidant activity (DPPH scavenging, metal chelating, and Cupric ion reducing antioxidant capacities), α-amylase and α-glucosidase inhibitory effects. No correlation between phenolic content and antioxidant and enzyme inhibitory activities of A. sicula L. extracts was observed. Conclusion: The results showed that this plant could be a significant source of medically important natural compounds.

Alpha-amylase Inhibitory Activity of Extracts from Algerian Calamintha nepeta (L.)

Background:: Calamintha nepeta is a plant from the Lamiaceae family that is known for its traditional use to treat diabetes among Algerian populations. However, till now, there has been no research work to confirm this activity. Objectives:: This work aimed to evaluate the amylase inhibitory activity of essential oils and phenolic compounds from both methanolic and aqueous extracts of Algerian Calamintha nepeta (L.). Methods:: The essential oil was obtained by hydrodistillation and analyzed using GC and then GC/MS. Aqueous and methanolic extracts were obtained from the remains of the hydrodistillation. Total phenolic compounds were quantified using the Folin-Ciocalteu method. The amylase inhibitory activity of the extracts was determined by testing their ability to inhibit alpha-amylase. Results:: The extraction yield was 0.67 % (w/w) for the essential oil, and 11.85 and 4.38 % (w/w) for the aqueous and methanolic extracts, respectively. The essential oil analysis revealed that menthone, menthol, pulegone, and pulegone oxide were the main components of the oil. The total phenolic compounds in the aqueous and methanolic extracts were 41.81 and 32.92 mg GAE/g DW, respectively. The extracts inhibited α-amylase activity with IC50 values of 24.46, 31.54, and 115.47 mg/ml for the methanolic extract, essential oil, and aqueous extract, respectively. Conclusion:: The different extracts of Calamintha nepeta showed an interesting composition and significant amylase inhibitory activity, emphasizing their successful use in traditional medicine.

Secretome analysis revealed that cell wall remodeling and starch catabolism underlie the early stages of somatic embryogenesis in Pinus nigra.

Somatic embryogenesis is an efficient mean for rapid micropropagation and preservation of the germplasm of valuable coniferous trees. Little is known about how the composition of secretome tracks down the level of embryogenic capacity. Unlike embryogenic tissue on solid medium, suspension cell cultures enable the study of extracellular proteins secreted into a liquid cultivation medium, avoiding contamination from destructured cells. Here, we present proteomic data of the secretome of Pinus nigra cell lines with contrasting embryogenic capacity, accounting for variability between genotypes. Our results showed that cell wall-related and carbohydrate-acting proteins were the most differentially accumulated. Peroxidases, extensin, α-amylase, plant basic secretory family protein (BSP), and basic secretory protease (S) were more abundant in the medium from the lines with high embryogenic capacity. In contrast, the medium from the low embryogenic capacity cell lines contained a higher amount of polygalacturonases, hothead protein, and expansin, which are generally associated with cell wall loosening or softening. These results corroborated the microscopic findings in cell lines with low embryogenic capacity-long suspensor cells without proper assembly. Furthermore, proteomic data were subsequently validated by peroxidase and α-amylase activity assays, and hence, we conclude that both tested enzyme activities can be considered potential markers of high embryogenic capacity.

Association between Salivary Cortisol and α-Amylase with the Psychological Profile of Patients with Oral Lichen Planus and Burning Mouth Syndrome: A Case-Control Study.

The aim of our study was to assess the relationship between the concentration/activity of salivary stress biomarkers (cortisol, α-amylase) and the psychological profile of patients with oral lichen planus (OLP) and primary burning mouth syndrome (BMS). A total of 160 subjects participated in this case-control study: 60 patients with OLP; 60 patients with primary BMS; and 40 control subjects. Unstimulated whole saliva (UWS) was collected between 9 and 10 a.m. Salivary biomarkers were analyzed by enzyme-linked immunosorbent assays (ELISAs). Psychological assessment was evaluated with the Depression, Anxiety, and Stress Scale (DASS-21). The patients with primary BMS had higher salivary cortisol concentrations and α-amylase activity (0.52 vs. 0.44 µg/dL; 160,531 vs. 145,804 U/L; one-way analysis of variance (ANOVA) with post hoc Scheffe test) compared with patients with OLP. The patients with primary BMS had statistically significant higher scores for depression, anxiety, and stress compared with patients with OLP and control subjects (p < 0.001, Kruskal-Wallis test). There was a strong positive correlation between anxiety and depression, stress and depression, and stress and anxiety in patients with OLP and BMS (p < 0.001 and p < 0.001, respectively; Spearman's correlation). There was a good positive correlation between symptom intensity (pain/burning) and psychological profile (depression, anxiety, stress) in patients with primary BMS (r = 0.373, p = 0.003; r = 0.515, p < 0.001; r = 0.365, p = 0.004, respectively; Spearman's correlation). This case-control study is the first to compare the psychoendocrinological profile of patients with two different oral diseases. The patients with BMS showed a higher concentration/activity of salivary stress biomarkers (cortisol, α-amylase) and a stronger association with mental disorders compared with patients with OLP. However, an interdisciplinary psychoneuroimmunological approach is equally important in both patient groups (OLP and BMS), regardless of whether mental disorders are the cause or the consequence.

Microbial Community Affects Daqu Quality and the Production of Ethanol and Flavor Compounds in Baijiu Fermentation.

Daqu is a traditional starter for Baijiu fermentation and is produced by spontaneous fermentation of ground and moistened barley or wheat. The quality of Daqu is traditionally evaluated based on physicochemical and subjective sensory parameters without microbiological analysis. Here, we compared the physicochemical characteristics of qualified (QD) and inferior (ID) Daqu, their microbial communities based on plate counting and PacBio SMRT sequencing of rRNA gene libraries, and their impacts on Baijiu fermentation. The results showed that the glucoamylase and α-amylase activities of QD were significantly higher than those of ID. The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium Bacillus licheniformis and fungi Saccharomycopsis fibuligera and Lichtheimia ramosa, were significantly higher in QD than in ID. The laboratory-scale Baijiu fermentation tests showed that the relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture content in the former. Consequently, more glycerol, acetic acid, ethanol, and other volatile compounds were produced in the QD than in the ID fermentation set. The results suggest that Daqu quality is determined by, and can be evaluated based on, its microbial community.

Correlation of Germination, Seedling Vigour Indices and Enzyme Activities in Response to Liquid Organic Kunapajala to Predict Field Emergence in Late Sown Wheat

A laboratory experiment was conducted to correlate the germination test with seed vigour parameters and enzyme activities to predict seedling vigour and planting value on late sown wheat variety UP-2526. The experiment was conducted at GBPUA and T, Pantnagar during rabi season of 2020-2. The experiment consisted of five treatments viz; no priming (control), hydropriming, 10%, 25% and 50% kunapajala priming for 16 hrs. Results revealed that germination percentage was positively and significantly correlated with speed of germination (0.914*), seedling vigour index-II (0.890*), α-amylase activity at 12 and 16 hrs of priming (0.942* and 0.947*, respectively), seed reserve mobilization efficiency on 4th day (0.954*) after incubation and imbibition rate after 16 and 24 hrs of soaking duration (0.933* and 0.894*, respectively). Heat stress both low and high temperature are major reason of declining yield in wheat when sown delayed. Prediction of seedling vigour and field emergence of seed before sowing is prime important for assured yield in late sown condition.

A promising microbial α-amylase production, and purification from Bacillus cereus and its assessment as antibiofilm agent against Pseudomonas aeruginosa pathogen

Background and aimThe purpose of the current study is to isolate a heavily amylase-producing bacteria of the genus Bacillus from soil samples, optimize the production of the enzyme, purify it, and evaluate its activity against biofilm-producing bacteria. A total of 12 soil samples were collected and screened for promising Bacillus species with good amylolytic activity. Isolation was done by serial dilution and plating technique and amylolytic activity was determined by starch agar plate method. Among the 12 Bacillus isolates recovered from soil samples, 7 showed positive α-amylase production. The best isolate that recorded the greatest amylolytic activity was selected for further studies. This isolate was identified by 16S rRNA sequencing as Bacillus cereus and registered under gene bank accession number OP811897. Furthermore, the α-amylase enzyme was produced by a submerged fermentation technique using best production media and partially purified by ammonium sulfate and chilled ethanol and molecular weight had been determined by SDS-PAGE gel electrophoresis. The production of α-amylase was optimized experimentally by one-factor at a time protocol and statistically by Plackett–Burman design as well as RSM CCD design. Data obtained from OFAT and CCD revealed that α-amylase activities were 1.5- and twofold respectively higher as compared to un-optimized conditions. The most significant factors had been identified and optimized by CCD design.ResultsAmong the eleven independent variables tested by PBD, glucose, peptone, (NH4)2SO4, and Mg SO4 were the most significant parameters for α-amylase production with an actual yield of 250U/ml. The best physical parameters affecting the enzyme production were incubation time at 35 °C, and pH 5.5 for 48 h. The partially purified enzyme with 60% ammonium sulphate saturation with 1.38- fold purification showed good stability characteristics at a storage temperature of 4 °C and pH up to 8.5 for 21 days. Antibiofilm activity of purified α-amylase was determined against Pseudomonas aeruginosa (ATCC 35659) by spectrophotometric analysis and CLSM microscopic analysis. Results demonstrated biofilm inhibition by 84% of the formed Pseudomonas biofilm using a microtiter plate assay and thickness inhibition activity by 83% with live/Dead cells percentage of 17%/83% using CLSM protocol.ConclusionsA highly stable purified α-amylase from B. cereus showed promising antibiofilm activity against one of the clinically important biofilm-forming MDR organisms that could be used as a cost-effective tool in pharmaceutical industries.

Synthesis, in vitro α-glucosidase, α-amylase activities and molecular docking study of hybrid thiazole-sulfonohydrazide analogues

Thiazole-sulfonohydrazide hybrid analogues (1-15), were synthesized and characterized through different techniques such as NMR, HR-EIMS and evaluated against α-glucosidase and α-amylase enzymes. In case of α-glucosidase, analogues 4 (IC50 = 4.60 ± 0.30 µM) while in case of α-amylase, analogue 1 (IC50 = 5.10 ± 0.20 µM) is the most potent among the series confirmed from both the experimental and molecular docking study. Structure activity relationship was carried out for all analogues which mainly depend upon number, nature, position, and electron donating/withdrawing effects of the substituent/s on phenyl ring. Molecular docking study was carried out to show the binding interaction of the most potent analogue with the active site of enzyme.

Green Synthesis of Magnetic Nanoparticles from Oldenlandia diffusa: Characterization and Therapeutic Activities

This study investigated green synthesis of magnetic nanoparticles (MNP) using Oldenlandia diffusa, its cauterization, and therapeutic propertieson liver cancer cells via an in-vitro approach. Anti-cancer, anti-oxidant, and anti-diabetic properties of MNP were evaluated. Synthesis of MNP was confirmed via UV-visible spectroscopy. Oldenlandia diffusa MNP (20–40 nm) showed absorption peak at 327 nm in UV-visible, XRD, EDX and FTIR spectral analysis. MNP were monoclinic, and rhombohedral with two stretching peaks at 646 cm−1, and 1098 cm−1 confirming Fe–O–Fe mode and Fe = O due to the iron element. IC50 values for MNP (IC50 74 μg/ml &amp; 58 μg/ml) using DPPH and ABTS methods were high as compared to aqueous leaf extract of Oldenlandia diffusa confirming anti-oxidant properties. MNP exhibited α-amylase inhibitory activity with maximum inhibition of 82.17±0.82 μg/ml for α-glucosidase inhibitory action of 84.82±0.89 μg/ml. MNP showed dose-dependant in-vitro tumor suppression activity against HepG2 cells (16.08% at 150 μg/ml and 28.31% at 150 μg/ml). MNP also demonstrated anti-leishmanial activity at 400 g/ml (74.26±0.82 g/ml for promastigotes and 69.40±0.69 μg/ml for amastigotes). Oldenlandia diffusa actively bonded with magnetic Fe-nanoparticles and suppressed the growth of HepG2 cells. It demonstrated anti-cancer, antioxidant, anti-leishmanaland anti-diabetic activities. Thus, Oldenlandia diffusa is a potential anti-cancer therapeutic drug for liver cancer.

Xanthine oxidase, α-glucosidase and α-amylase inhibitory activities of the essential oil from Piper lolot: In vitro and in silico studies

IntroductionPiper lolot is a species of herb used as a popular food in Vietnam. Furthermore, the species has been used as a Vietnamese traditional medicine to treat many diseases. MethodsChemical constituents in the essential oil from leaves of Piper lolot were determined using GC/MS analysis. The anti-gout and anti-diabetic activities of the essential oil were determined through the inhibitory assays against xanthine oxidase, α-glucosidase and α-amylase enzymes. In addition, molecular docking simulations were used to elucidate the inhibitory mechanism between the main compounds and the enzymes. ResultsThe dominant constituents of the Piper lolot essential oils were determined as β-caryophyllene (20.6%), β-bisabolene (11.6%), β-selinene (8.4%), β-elemene (7.7%), trans-muurola-4(14),5-diene (7.4%), and (E)-β-ocimene (6.7%). The essential oil displayed xanthine oxidase, α-amylase, and α-glucosidase inhibitory activities with IC50 values of 28.4, 130.6, and 59.1 μg/mL, respectively. The anti-gout and anti-diabetic activities of the essential oil from the P. lolot species are reported for the first time. Furthermore, molecular docking simulation was consistent to in vitro experiments. ConclusionThe present study provides initial evidence that the essential oil of P. lolot may be a potential natural source to develop new diabetes preparations.