Glucoamylase Activity Research Articles

Synergistic effects of multiple enzymes from industrial Aspergillus niger strain O1 on starch saccharification

BackgroundStarch is one of the most important renewable polysaccharides in nature for production of bio-ethanol. The starch saccharification step facilitates the depolymerization of starch to yield glucose for biofuels production. The filamentous fungus Aspergillus niger (A. niger) is the most used microbial cell factory for production of the commercial glucoamylase. However, the role of each component in glucoamylases cocktail of A. niger O1 for starch saccharification remains unclear except glucoamylase.ResultsIn this study, we identified the key enzymes contributing to the starch saccharification process are glucoamylase, α-amylase and acid α-amylase out of 29 glycoside hydrolases from the 6-day fermentation products of A. niger O1. Through the synergistic study of the multienzymes for the starch saccharification in vitro, we found that increasing the amount of α-amylase by 5-10 times enhanced the efficiency of starch saccharification by 14.2-23.2%. Overexpression of acid α-amylase in strain O1 in vivo increased the total glucoamylase activity of O1 cultures by 15.0%.ConclusionsOur study clarifies the synergistic effects among the components of glucoamylases cocktail, and provides an effective approach to optimize the profile of saccharifying enzymes of strain O1 for improving the total glucoamylase activity.

IRRADIATION OF SOUND WAVES TO ASPERGILLUS KAWACHII AND THE CHARACTERIZATION OF ENZYME ACTIVITIES IN RICE-KOJI

Conidiospores of A. kawachii were irradiated with sound waves at three different frequencies, 1.0, 6.3, and 16.0 kHz, with a constant sound pressure of 5.0 dB. Steamed rice was inoculated with the resulting conidiospores and incubated at 25°C for 30 h to make rice-koji. By irradiation with sound waves at 6.3 kHz to conidiospores of A. kawachii, the activities of glucoamylase and acid protease of rice-koji were increased by 1.33 and 1.37 times, respectively, over that of rice-koji prepared without sound wave irradiation. The amount of mycelium in rice-koji prepared with conidiospores treated by sound wave irradiation at 6.3 kHz was also 1.31 times higher than that prepared without sound wave irradiation. To confirm the usefulness of sound wave irradiation as a condition for making rice-koji, the effects of sound waves on enzyme activities and mycelium weight of rice-koji produced by sound-treated conidiospores of A. kawachii were investigated.Keywords: Aspergillus kawachii, rice-koji, sound wave, glucoamylase, acid protease

누룩으로부터 다양한 곰팡이의 선별과 전분 분해 활성을 이용한 동시당화발효

Various fungi were isolated from Korean traditional Nuruk and identified as ten types of fungal strains such as L. corymbifera, L. ramose, S. racemosum, R. oryzae, R. pusillus, M. racemosus, M. circinelloide, A. luchuensis, A. flavus, and A. fumigatus. Among them, four strains (A.fumigatus, A. luchuensis, A. flavus, and R. oryzae) exhibited relatively high glucoamylase activities. When the optimum reaction temperatures were verified for glucoamylase activity, A. fumigatus, A. luchuensis, and A. flavus showed the highest glucoamylase activity at 60℃, and R. oryzae showed the highest glucoamylase activity at 50℃. When simultaneous saccharification and fermentations were performed with yeast, R. oryzae showed the fastest starch degradation rate (1.17 ± 0.10 g/L·h) and the highest ethanol production (17.17 ± 1.46 g/L) for 72 hours.

Integration of Solid State and Submerged Fermentations for the Valorization of Organic Municipal Solid Waste.

Solid state fermentation (SsF) is recognized as a suitable process for the production of enzymes using organic residues as substrates. However, only a few studies have integrated an evaluation of the feasibility of applying enzymes produced by SsF into subsequent hydrolyses followed by the production of target compounds, e.g., lactic acid (LA), through submerged-liquid fermentations (SmF). In this study, wheat bran (WB) was used as the substrate for the production of enzymes via SsF by Aspergillus awamori DSM No. 63272. Following optimization, cellulase and glucoamylase activities were 73.63 ± 5.47 FPU/gds and 107.10 ± 2.63 U/gdb after 7 days and 5 days of fermentation, respectively. Enzymes were then used for the hydrolysis of the organic fraction of municipal solid waste (OFMSW). During hydrolysis, glucose increased considerably with a final value of 19.77 ± 1.56 g/L. Subsequently, hydrolysates were fermented in SmF by Bacillus coagulans A166 increasing the LA concentration by 15.59 g/L. The data reported in this study provides an example of how SsF and SmF technologies can be combined for the valorization of WB and OFMSW.

Effect of moderate electric field on glucoamylase-catalyzed hydrolysis of corn starch: Roles of electrophoretic and polarization effects

This study aimed to investigate the effect of moderate electric field (MEF, 0–10 V/cm, 50 Hz) on the glucoamylase-catalyzed hydrolysis of corn starch. The underlying mechanism was explored by monitoring changes in the hydrolysis rate, glucoamylase activity, substrate structure, temperature profiles, and hydrolysate properties. The results suggested that the hydrolysis rate highly depended on the MEF intensity. Low-intensity MEF (0–5 V/cm) increased glucoamylase activity by 7.1–22.4% by inducing mild electrophoretic and polarization effects, which resulted in the formation of porous starch. Although high-intensity MEF accelerated the thermal inactivation of glucoamylase, it completely destroyed starch granules due to the extensive ohmic heating; hence, a significant improvement in the hydrolysis efficiency and dramatic decreases in the pasting viscosity, gelatinization enthalpy, and thermo-stability were observed. Overall, this study clarified the mechanism of MEF-assisted enzymatic hydrolysis, which might contribute to expanding the applications of electric field-based techniques in starch modification.

Germinated Brown Rice Preparation for Value Added Material for Healthy Brewed Vinegar

Soaking grains in water during the preparation of germinated brown rice (GBR) can result in the multiplication of bacterial contaminants. To address this problem, a system was designed to automatically change the soaking water every 6 h. A significant reduction of the contaminants was observed. GBR was saccharified by mold bran Amylomyces rouxii. The 5 day saccharified GBR that contained the highest -amylase and glucoamylase activities was further used for alcohol fermentation by yeast Saccharomyces cerevisiae. Then, acetic acid was produced by Acetobacter aceti through a semi-continuous process. In the evaluation of the nutritional quality during processing, significant increments in the levels of -aminobutyric acid (GABA), antioxidant activities (DPPH), and total phenolic contents were found during soaking, but these levels progressively decreased in wine and were lowest in vinegar. Moreover, the soaking period from 36 h to 48 h had no significant effect on these substances. GC-MS analysis indicated that four important volatile organic compounds in the produced wine and vinegar were reported for their antimicrobial activity. Furthermore, no change in GABA was found in the vinegar over 6 months of storage. Thus, using this method could successfully produce brewed vinegar with health benefits from GBR.

Fishmeal Replacement with Hermetia illucens Meal in Aquafeeds: Effects on Zebrafish Growth Performances, Intestinal Morphometry, and Enzymology

Fishmeal (FM) is still the most important protein source in aquafeeds. However, due to the reduction of wild fish stocks used for FM production, its manufacturing it is now unsustainable. Insect meal represents a valid alternative to FM, due to the low carbon footprint of its production and its high nutritional value. The aim of this study was to investigate the potentials of replacing FM with black soldier fly (Hermetia illucens) meal (HIM) in aquafeeds, using zebrafish as the animal model. Four diets were formulated with increasing HIM/FM replacement rate (the control diet contained 20% FM). Mortality rates, growth performances, and feed consumptions were measured, and fish intestine samples were collected for histological and enzymatic analysis. After 49 days, all groups almost tripled their initial body weight (cumulative body weight gain ranged between 143.9 and 155.2 mg), and no statistically significant differences among treatments were observed in relation to growth performances and histological traits. Contrarily, trypsin, alkaline phosphatases, and alpha amylase–glucoamylase activities were significantly reduced when the FM replacement rate was increased. In conclusion, HIM may represent an alternative to FM, since no adverse effects were observed when it was included up to 20% in the zebrafish diet, even when replacing 100% of the FM.

Peak-temperature effects of starter culture (Daqu) on microbial community succession and volatile substances in solid-state fermentation (Jiupei) during traditional Chinese special-flavour Baijiu production

Daqu is the natural mixed starter culture for special-flavour Baijiu (the unique famous Baijiu in Jiangxi Province) brewing. Peak-temperature effects of Daqu on chemical compositions, microbial community succession and volatile substances in Jiupei fermented with middle peak-temperature Daqu (MTJP) and Jiupei fermented with high peak-temperature Daqu (HTJP) during special-flavour Baijiu brewing were determined. It was found that ethanol and reducing sugar had significantly (P < 0.05) higher contents in MTJP than HTJP. Peak-temperature of Daqu had a greater impact on the fungal community than the bacterial community in Jiupei. The total content of volatile substances in HTJP was 1.5–3 times of those in MTJP during fermentation. Most esters were positively correlated with Pichia, Lactobacillus and Bacillus genera in HTJP, but positively correlated with Aspergillus, Monascus, Pichia and Lactobacillus genera in MTJP. In a word, middle peak-temperature Daqu (MT Daqu) could enhance the ethanol production through Aspergillus genus with high glucoamylase activity and high peak-temperature Daqu (HT Daqu) could enhance the accumulation of volatile substances through more abundant flavour-producing microorganisms. Our study have provided theoretical basis for the further research on peak-temperature of Daqu effects on the quality of various Chinese Baijiu.

Amylase Production by Aspergillus niger immobilized in Microporous Calcium Alginate Gel Beads

Microporous calcium alginate gel beads were investigated as potential solutions to mass transfer limitations in immobilized cultures. The beads were prepared by gelling mixtures of sodium alginate and fillers (starch or granulated sugars) in calcium chloride solution. The resulting beads were cured in the same solution, during which the fillers leached out of the beads thereby creating micro-pores in the beads (microporous beads). The effectiveness of the microporous beads in improving amylase production by Aspergillus niger LC 269109 was investigated. Spores of A. niger were immobilized in the microporous beads and used for batch alpha amylase and gluco amylase production. Amylase production by the A. niger immobilized in the microporous beads were significantly higher (p&lt;0.01) than the values obtained with the conventional calcium alginate gel beads. Under all the conditions investigated, gluco-amylase activities were significantly (p&lt;0.01) higher than the alpha-amylase activities. Under the optimum conditions of inoculum concentration (1.0 × 105 spores/ml), pH (6), temperature (35°C), bead diameter (3 mm) and calcium chloride concentration (1.5%), the gluco-amylase and alpha amylase activities were 11.98 U/ml and 6.7 U/ml respectively, which were significantly higher (p&lt;0.05) than the 7.8 U/ml and 3.2 U/ml obtained with the conventional gel beads.

Optimization of α‐amylase and Glucoamylase Production Using Cull Potatoes as Substrate

AbstractAmylases are required for the conversion of starchy substrate into sugars. Commercially available enzymes are quite costly which makes the process uneconomical. This study is conducted to standardize physico‐chemical parameters such as substrate concentration (1.0–5.0%), temperature (25–40 °C), pH (4.0–7.0), incubation time (18–24) h for α‐amylase and 3–6 days for glucoamylase production) for optimum production of α‐amylase from bacterial isolate (AM1) and glucoamylase from Aspergillus niger by using cull potatoes as a substrate. Various organic and inorganic nitrogen sources (urea, yeast extract and soybean meal, and ammonium sulphate) are tried for maximum enzyme production. Among the four nitrogen sources, yeast extract supported maximum α‐amylase and glucoamylase production. Among the different amylolytic isolates from fermented jalebi dough and AM1culture, maximum α‐amylase activity is shown by AM1 (90.46 U mL−1) as compared to J1 (71.02 U mL−1). After optimization, α‐amylase activity of AM1 increases by 41.73% from 198.20 to 280.92 U mL−1 at 5.0% substrate concentration, 30 °C temperature, 24 h of incubation and pH 5.0. Glucoamylase activity of A. niger increases by 38.78% from 228.72 to 317.44 U mL−1 after optimization at 5% substrate concentration, pH 5, incubation period of 4 days and temperature 30 °C.

Inhibition of α-glucosidases by tea polyphenols in rat intestinal extract and Caco-2 cells grown on Transwell

Inhibition of maltase, sucrase, isomaltase and glucoamylase activity by acarbose, epigallocatechin gallate, epicatechin gallate and four polyphenol-rich tea extract from white, green, oolong, black tea, were investigated by using rat intestinal enzymes and human Caco-2 cells. Regarding rat intestinal enzyme mixture, all four tea extracts were very effective in inhibiting maltase and glucoamylase activity, but only white tea extract inhibited sucrase and isomaltase activity and the inhibition was limited. Mixed-type inhibition on rat maltase activity was observed. Tea extracts in combination with acarbose, produced a synergistic inhibitory effect on rat maltase activity. Caco-2 cells experiments were conducted in Transwells. Green tea extract and epigallocatechin gallate show dose-dependent inhibition on human sucrase activity, but no inhibition on rat sucrase activity. The opposite was observed on maltase activity. The results highlighted the different response in the two investigated model systems and show that tea polyphenols are good inhibitors for α-glucosidase activity.

USE OF COMPOSITE AGRO-SUBSTRATES FOR AMYLOGLUCOSIDASE SYNTHESIS AND CHARACTERIZATION BY Aspergillus niger OTF AND Aspergillus flavus CLOR1 USING SOLID STATE FERMENTATION

Amyloglucosidase catalyses the hydrolysisof glycosidic residues from non-reducing ends of amylose and amylopectin in starch components to produce β-D-glucose for industrial processes. The utilization of composite agro-substrates for amyloglucosidase production byAspergillus niger OTF and A. flavus CLOR1 using solid state fermentation and characterization of the enzyme were investigated. The substrates include rice bran (R), soybeans flour (S), palm kernel cake (P), wheat bran (W) and oyster shell (O) at various compositions (Medium I – VIII) were supplied with adequate moisture content for a solid culture medium of fermentation.They were inoculated into with the isolates and incubated at 30 °C for 120 h respectively. Cultural conditions such as temperature, pH and storage stability were optimized. Medium I (WSPO; 100:2:3:1, w/w) yielded amyloglucosidase activity 83.92 Ug-1and Medium V (WSP; 100:2:3, w/w) resulted into activity 67.64 Ug-1 at 48 h optimal time. There was decline in activity after 48 h in all samples but with maximum activity at pH 5. Aspergillus niger OTF showed maximum amyloglucosidase activity23.5 Ug-1 as compared with A. flavus CLOR1 20.07 Ug-1 at 30 ºC. The residual activities in term of storage stability were 43.9% and 44.9% at 4 °C and 68. 6% and 27.8% at 28 °C at week 2 respectively which later declined over a period of time. This study revealed that higher glucoamylase activity was significantly enhanced using these inexpensive and readily available agro-residues by both strains of isolates in solid culture medium. Thus, these residues could be a potential and economic source for the production of amyloglucosidase.

Effects of α-amylase and glucoamylase on the characterization and function of maize porous starches

To overcome the limited surface area of starch and improve the adsorption capacity of starch, porous starch has been widely produced in various fields. In this study, the different enzyme activities of α-amylase (AM), glucoamylase (GAM), and mixed enzyme (ME) were used to prepare different types of porous maize starch, and the microstructure, particle morphology, adsorption, and gelatinization characteristics of the porous starch were studied. Scanning electron microscopy showed porous structures with diverse pore size distribution and pore area depending on the enzyme type and its activities; AM produced the largest holes, GAM produced the deepest holes, and ME produced large and deep holes. Adsorptive capacity was significantly affected by enzymatic modification being greater influenced by GAM. The porous starches had higher relative crystallinity as deduced from X-ray diffraction and Fourier transform infrared spectroscopy. The MA-treated starch had higher solubility whereas swelling capacity, peak viscosity, final viscosity, breakdown, and setback of both treatments were decreased compared to the native starch. The results indicate porous maize starch can provide different functions according to the action pattern of enzymes. The type of enzyme and its enzyme activity can be used to produce the ideal cavity and pore size starch granules, which expands its application scope.

Partial Characterization of Glucoamylase Crude Enzyme Produced by &lt;em&gt;Aspergillus&lt;/em&gt; and &lt;em&gt;Rhizopus&lt;/em&gt; Strains

Glucoamylase is widely used in the food industry to produce high glucose syrup, and also in fermentation processes for production of beer and ethanol. In this work glucoamylase enzyme produced by six fungal strains were previously isolated from different Sudanese soils, crop seeds, rotten fruits and pieces of moistened bread designated as Aspergillus awamori (A1and A7), A. niger (A10) , A. tamari (Aw), A. terrus (At) and Rhizous oryzae (R3) in a liquid culture was evaluated and characterized. The maximum temperature of glucoamylase activity are found to be in the range of 60-70˚C and at pH value of 5.0-6.0 and the activity of all enzymes from all isolates increased with increase of the concentration of soluble starch. Also the activity of the enzyme from all isolates under study increase with increase of time reaction.

누룩곰팡이 Aspergillus oryzae OF5-20를 이용한 쌀 품종별 고상종국제조 및 품질특성

The quality characteristics of solid starters manufactured from two types of rice samples have been reported herein. The rice samples were inoculated with Aspergillus oryzae OF5-20. It was isolated from ‘Nuruk’, a traditional fermentation starter, and exhibited high enzyme activity. The water absorption rate of rice, the raw material, reached the maximum within 160 min at ‘Samgwang’ and in 10 min at ‘Jeonju 615’. The quality evaluation tests revealed that among the for two solid starters, ‘Samgwang’ and ‘Jeonju 615’, Samgwang exhibited a higher acidity and amino acidity. As a result of the enzyme activity according to the inoculation ratio of A. oryzae OF5-20, the α-amylase showed the highest activity in ‘Samgwang’ solid starter inoculated with 4% of A. oryzae OF5-20 and ‘Jeonju 615’ solid starter with 6% inoculation. The glucoamylase activity was 1.4 times higher when the solid starter was inoculated with 4% of the liquid fungus (‘Samgwang’, 1,592.8 unit/g) than the enzyme activity when the solid starter was inoculated with 2% of the liquid fungus (1,137.8 unit/g). Since organic acids have a high ratio of citric acid and amino acids are composed of 20 kinds, such as glutamic acid, alanine, and phenylalanine, the solid starter, according to rice varieties, showed a difference in the formation of organic acids and free amino acids. Therefore, this research is expected to contribute to the improvement of the depressed starter industry and the quality of our ‘Yakju’ by the quality uniformity of solid starter manufacture using the brewing fungus with having good enzyme activity.

PSIX-7 Grazing toxic endophyte-infected tall fescue does not influence pancreatic or small intestinal digestive enzyme activities in beef steers

Abstract The objective of this experiment was to determine the influence of toxic endophyte-infected tall fescue exposure on pancreatic and small intestinal digestive enzyme activities in steers. Twelve fescue-naive beef steers [693 ± 42.7 kg of body weight (BW)] were stratified by BW and randomly assigned within BW ranks to graze non-toxic endophyte-infected tall fescue (NTE, n = 6; 0.01 ± 0.009 mg ergovaline + ergovalinine/kg) or toxic endophyte-infected tall fescue (TE, n = 6; 0.50 ± 0.048 mg ergovaline + ergovalinine/kg) pastures for 84 d. After the grazing period, steers were weighed and then slaughtered in three groups for tissue collection. A 1-m segment of the small intestine was collected 5-m distal to the pyloric sphincter. Subsamples of the small intestinal mucosa and pancreas were collected, homogenized in saline, and assayed for protein concentration. Pancreatic and small intestinal digestive enzyme activities were assayed. Data were analyzed using the GLM procedure of SAS as a randomized complete block design for effects of treatment and slaughter group (blocking factor). Steers grazing NTE pastures had a greater (P &amp;lt; 0.001) average daily gain (0.282 vs -0.631 kg/d) and final BW at slaughter (739 vs 620 kg) than steers grazing TE pastures. Small intestinal segment mass and mucosal density (P ≥ 0.16) were not influenced by treatment. Grazing TE pasture did not influence (P ≥ 0.21) pancreatic or small intestinal protein concentrations. Pancreatic α-amylase and trypsin activity per gram pancreas (P ≥ 0.21) or per gram pancreatic protein (P ≥ 0.30) were not influenced by fescue treatment. Small intestinal glucoamylase, isomaltase, and maltase activities did not differ between steers grazing NTE or TE pastures when expressed per gram of intestinal tissue (P ≥ 0.47) or per gram of intestinal protein (P ≥ 0.60). These data indicate that decreased gains observed in cattle consuming TE are not a result of decreased pancreatic or small intestinal digestive enzyme activities.

PENGARUH KELEMBAPAN RELATIF DAN SUHU TERHADAP AKTIVITAS GLUKOAMILASE ASPERGILLUS FLAVUS PADA PENYAKIT SIMPANAN GAPLEK

The effect of relative humidity and temperatur to glucoamylase activity of Aspergillus flavus on storage disease of dried cassava. Aspergillus flavus is the most important species because of its toxigenic caracteristic on agricultural product. Among several Aspergillus species growing on dried cassava. This study was conducted to show the role of glucoamylase produced by Aspergillus flavus fowards the storage disease of dried cassava. The effect of RH and storage room temperature to glucoamylase activity was evaluated for 4 months using Randomized Completely Block Design (Factorial). Variables observed were glucoamylase activity and starch content of dried cassava. Glucoamylase activity could be used as an early indicator of the infestation of dried cassava by Aspergillus while the change of dried cassava color had not been visible. Starch content of dried cassava decreased during the storage. Due to the glucoamylase activity of A. flavus which degrading starch into glucose. The interaction effect of RH and storage room temperature to glucoamylase activity of A. flavus was significant.

Influence of dietary fructose supplementation on visceral organ mass, carbohydrase activity, and mRNA expression of genes involved in small intestinal carbohydrate assimilation in neonatal calves

The hypothesis of this experiment was that dietary fructose would influence visceral organ mass, carbohydrase activity, and mRNA expression of carbohydrases and nutrient transporters in the small intestine in neonatal calves. Therefore, our objective was to use the neonatal calf as a model to evaluate the effects of postruminal fructose supply on small intestinal carbohydrate assimilation. Ten calves (<7 d of age; 41.2 ± 1.46 kg of body weight) were fed milk replacer at 2.0% of body weight daily (816 ± 90.5 g/d; 272 ± 30.1 g/L; dry-matter basis) in 2 equal portions and assigned to the following dietary treatment groups: (1) milk replacer (control; n = 6) or (2) milk replacer + 2.2 g of fructose/kg of body weight (fructose; n = 4). Calves were fed dietary treatments for 28 d, with jugular blood sampled every 7 d before and after the morning feeding. Calves were slaughtered, and visceral weights were recorded. Postruminal carbohydrase activities were assayed. Quantitative real-time PCR was conducted for small intestinal mRNA expression of nutrient transporters [solute carrier family 2 member 5 (GLUT5), solute carrier family 2 member 2 (GLUT2), and solute carrier family 5 member 1 (SGLT1)], carbohydrases (lactase, maltase-glucoamylase, and sucrase-isomaltase), and ketohexokinase (KHK). Data were analyzed using MIXED procedures in SAS version 9.4 (SAS Institute Inc, Cary, NC). Dietary fructose supplementation decreased serum glucose concentration. Small intestinal mass was greater in calves supplemented with fructose. Dietary fructose supplementation did not influence pancreatic α-amylase, small intestinal isomaltase, or maltase activities. Sucrase activity was undetected in the small intestine. Dietary fructose supplementation increased small intestinal glucoamylase activity per gram of tissue by 30% and increased maltase-glucoamylase mRNA expression by 6.8-fold. Dietary fructose supplementation did not influence mRNA expression of GLUT5, SGLT1, GLUT2, or KHK. Dietary fructose supplementation increased small intestinal lactase mRNA expression by 3.1-fold. Sucrase-isomaltase mRNA expression in the small intestine decreased 5.1-fold with dietary fructose supplementation. Dietary fructose supplementation does not induce sucrase activity in neonatal calves; however, sucrase-isomaltase may be transcriptionally regulated by dietary fructose in neonatal calves. More research is needed to compare glucose and fructose at isocaloric intakes to examine effects of dietary fructose at equal metabolizable energy intake.

Effects of nutrient restriction and melatonin supplementation from mid-to-late gestation on maternal and fetal small intestinal carbohydrase activities in sheep

The objective of this experiment was to evaluate the effects of nutrient restriction and melatonin supplementation during mid-to-late gestation on maternal and fetal small intestinal carbohydrase activities in sheep. Ewes were randomly assigned to one of 4 dietary treatments arranged in a 2 × 2 factorial design. Ewes were fed to provide 100% (adequate; ADQ) or 60% (restricted; RES) of nutrient recommendations, and diets were supplemented with either no melatonin (control; CON) or 5 mg melatonin/d (melatonin; MEL). This resulted in 4 treatment groups: CON-ADQ (n = 7), CON-RES (n = 8), MEL-ADQ (n = 8), MEL-RES (n = 8). Treatments began on day 50 of gestation, and ewes were euthanized on day 130 for tissue collection. The maternal and fetal small intestine were collected and assayed for small intestinal carbohydrase activities. Data were analyzed using the GLM procedure of SAS with fetal sex, melatonin, nutrition, and the melatonin by nutrition interaction included in the model statement. There were no melatonin by nutrition interactions for maternal or fetal small intestinal protein concentration or carbohydrase activities (P ≥ 0.11). Dietary melatonin supplementation decreased (P = 0.03) maternal small intestinal protein concentration by 22.7% and increased (P = 0.03) maternal small intestinal glucoamylase, isomaltase, and maltase activity per gram protein by 45.5%, 41.3%, and 40.6%, respectively. Nutrient restriction from mid-to-late gestation did not influence (P ≥ 0.46) maternal small intestinal protein concentration, or maltase, isomaltase, and lactase activity. Maternal glucoamylase activity per gram intestine increased (P = 0.05) with nutrient restriction by 49.1%. Melatonin supplementation and maternal nutrient restriction did not influence (P ≥ 0.15) fetal small intestinal protein concentration, or glucoamylase, isomaltase, and lactase activity. Maternal nutrient restriction from mid-to-late gestation decreased (P = 0.05) fetal maltase activity per gram intestine by 20.5% but did not influence fetal maltase activity per gram protein. These data indicate that some maternal and fetal carbohydrases are influenced by nutrient restriction and melatonin supplementation in sheep. More information is needed to understand how nutritional and hormonal factors regulate digestive enzyme activity in ruminants to design improved maternal nutrition programs to optimize fetal growth and development while maintaining maternal productivity.

Screening and evaluation of Monascus purpureus FJMR24 for enhancing the raw material utilization rate in rice wine brewing.

The rapid development of the rice wine industry has increased the demand for raw materials worldwide. A fungal strain with good adaptability to rice wine brewing conditions, which can also enhance the utilization rate of raw materials (URRM), thus increasing the production efficiency, was sought in the present research. The strain FJMR24 was successfully isolated and screened from 35 fermentation starters and exhibited high amylase activity (2200.9 ± 18.5 U g-1 ) and high glucoamylase activity (2330.4 ± 31.9 U g-1 ). Based on a morphological examination and a sequence analysis of the internal transcribed spacer (ITS) gene and β-tubulin gene, FJMR24 was identified as Monascus purpureus, which is an edible and versatile fungus that plays a dominant role in the processing of Hong Qu. A moderate pH of 5-6 under incubation at 35 °C for 5-6 days was favorable for the growth and enzyme production of FJMR24. The strain could also tolerate the extreme conditions of 15-45 °C, 18% ethanol (v/v), and an acidity of pH 2. The excellent fermentation adaptability of FJMR24 might enable it to retain high enzyme activity during rice wine brewing. As a result of the action of FJMR24, the URRM of the base liquor increased by around 26% due to increased starch hydrolysis efficiency, which was mainly due to the high unit enzyme activity of FJMR24. This study provides perspectives for the application of a M. purpureus strain with high starch hydrolysis activity for enhancing the URRM in traditional rice wine brewing. © 2020 Society of Chemical Industry.