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Markus R M Fiedler, Lars Barthel, Christin Kubisch, Corrado Nai, Vera Meyer
BACKGROUND: The lifestyle of filamentous fungi depends on the secretion of hydrolytic enzymes into the surrounding medium, which degrade polymeric substances into monomers that are then taken up to sustain metabolism. This feature has been exploited in biotechnology to establish platform strains with high secretory capacity including Aspergillus niger. The accepted paradigm is that proteins become mainly secreted at the tips of fungal hyphae. However, it is still a matter of debate if the amount of growing hyphal tips in filamentous fungi correlates with an increase in secretion, with previous studies showing either a positive or no correlation...
June 16, 2018: Microbial Cell Factories
Wesam H Abdulaal
BACKGROUND: Previous studies have demonstrated that members of Trichoderma are able to generate appreciable amount of extracellular amylase and glucoamylase on soluble potato starch. In this study the α-amylase was purified and characterized from Trichoderma pseudokoningii grown on orange peel under solid state fermentation (SSF). RESULTS: Five α-amylases A1-A5 from Trichodrma pseudokoningii were separated on DEAE-Sepharose column. The homogeneity of α-amylase A4 was detected after chromatography on Sephacryl S-200...
June 14, 2018: BMC Biochemistry
Sakayanathan Penislusshiyan, Loganathan Chitra, Iruthayaraj Ancy, Periyasamy Premkumar, Poomani Kumaradhas, Periasamy Viswanathamurthi, Thayumanavan Palvannan
In humans, alpha-glucosidase activity is present in sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM). α-glucosidase is involved in the hydrolyses of disaccharide into monosaccharides and results in hyperglycemia. Subsequently chronic hyperglycemia induces oxidative stress and ultimately leads to the secondary complications of diabetes. Hence, identifying compounds with dual beneficial activity such as efficient antioxidant and α-glucosidase inhibition property has attracted the attention in recent years...
June 6, 2018: International Journal of Biological Macromolecules
Nan-Nan Liu, Zhe Chi, Guang-Lei Liu, Tie-Jun Chen, Hong Jiang, Zhong Hu, Zhen-Ming Chi
A high molecular weight (Mw) pullulan has many potential applications in various fields. α-Amylase, glucoamylase and pullulanase were thought to play an important role in high Mw pullulan biosynthesis. However, there is no genetic evidence for this role. In this study, the genes encoding α-amylase, glucoamylase and pullulanase were cloned from Aureobasidium melanogenum P16, a high pullulan producing yeast and characterized. The proteins deduced from the cloned α-amylase gene, the glucoamylase gene and the isopullulanase gene, not a pullululanse gene had their corresponding conserved amino acid sequences, respectively...
June 1, 2018: International Journal of Biological Macromolecules
B Prabha, S Neethu, S Lekshmy Krishnan, D R Sherin, M Madhukrishnan, R Ananthakrishnan, K B Rameshkumar, T K Manojkumar, P Jayamurthy, K V Radhakrishnan
Phytochemical investigation of the stem bark of Myristica fatua Houtt. led to the isolation of a new compound 1 (3-tridecanoylbenzoic acid), along with six known acylphenols (2-7). All the compounds displayed moderate inhibitory activity on α-amylase and significant activity on α-glucosidase; however malabaricone B (6) and C (7) were identified as potent α-glucosidase inhibitors with IC50 values of 63.70 ± 0.546, and 43.61 ± 0.620 µM respectively. Acylphenols (compounds 3-7) also showed significant antiglycation property...
May 19, 2018: Bioorganic & Medicinal Chemistry
Robert J Shulman
Based on the developmental physiology of pancreatic amylase production, starch digestion in young infants was anticipated to be compromised whenever compared with that in older infants and toddlers. This appears to be the case, but with great variability among infants to digest starch. Evidence points to the importance of maltase-glucoamylase in young infants and its effect on starch digestion. These observations have critical importance for recommendations regarding the feeding of starch-containing foods to young infants...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Claudia C Robayo-Torres, Marisela Diaz-Sotomayor, Bruce R Hamaker, Susan S Baker, Bruno P Chumpitazi, Antone R Opekun, Buford L Nichols
BACKGROUND AND HYPOTHESES: Human starch digestion is a multienzyme process involving 6 different enzymes: salivary and pancreatic α-amylase; sucrase and isomaltase (from sucrose-isomaltase [SI]), and maltase and glucoamylase (from maltase-glucoamylase [MGAM]). Together these enzymes cleave starch to smaller molecules ultimately resulting in the absorbable monosaccharide glucose. Approximately 80% of all mucosal maltase activity is accounted for by SI and the reminder by MGAM. Clinical studies suggest that starch may be poorly digested in those with congenital sucrase-isomaltase deficiency (CSID)...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Buford L Nichols, Susan S Baker, Roberto Quezada-Calvillo
The mucosal maltase enzymes are characterized by an activity that produces glucose from linear glucose polymers, assayed with the disaccharide maltose. The related enzyme isomaltase produces glucose from branched glucose polymers, assayed with palatinose. Maltase and isomaltase activities are part of the 4 disaccharidases assayed from clinical duodenal biopsy homogenates. The reported maltase activities are more difficult to interpret than lactase or sucrase activities because both the sucrase-isomaltase and maltase-glucoamylase proteins have overlapping maltase activities...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Mahdi Amiri, Hassan Y Naim
The final step of carbohydrate digestion in the intestine is performed by 2 major α-glucosidases of the intestinal mucosa, sucrase-isomaltase (SI) and maltase-glucoamylase. Both of these enzymes are type II membrane glycoproteins, which share a significant level of homology in gene and protein structures and yet have differences in the posttranslational processing, substrate specificity and functional capacity. Insufficient activity of these disaccharidases particularly SI as a result of genetic mutations or secondary intestinal pathologies is associated with carbohydrate maldigestion and gastrointestinal intolerances...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Toshinao Goda, Kazue Honma
Two major α-glucosidase (maltase) genes, sucrase-isomaltase (SI) and maltase-glucoamylase (MGAM), respectively, are expressed in the small intestine. In this review, we have summarized whether jejunal expression of these maltase genes is regulated by dietary manipulations, which may affect carbohydrate availability from the luminal side, through changes in the binding of transcription factors and/or histone code on these genes. Studies using a model of mice fed either a low-starch or a high-starch diet for 7 days, found the mRNA levels of SI, MGAM, and Na-glucose cotransporter (SGLT1) genes in the jejunum to be increased in parallel by feeding a high-starch diet...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
David R Rose, Marcia M Chaudet, Kyra Jones
OBJECTIVES: Maltase-glucoamylase and sucrase-isomaltase are enzymes in the brush-border membrane of the small intestinal lumen responsible for the breakdown of postamylase starch polysaccharides to release monomeric glucose. As such, they are critical players in healthy nutrition and their malfunction can lead to severe disorders. METHODS: This review covers investigations of the structures and functions of these enzymes. RESULTS: Each consists of 2 enzyme domains of the glycoside hydrolase family GH31 classification, yet with somewhat differing enzymatic properties...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Byung-Hoo Lee, Bruce R Hamaker
Complete digestion of the glycemic carbohydrates to glucose takes place through the combined action of the 4 mucosal α-glucosidases (maltase-glucoamylase and sucrase-isomaltase) in the small intestine. Maltase digests α-1,2- and α-1,3-disaccharides better than the other α-glucosidases, and has, as well, the capability to effectively hydrolyze α-1,4 and α-1,6 linkages that form the major backbone of a starch molecule. This broad hydrolytic activity on α-linkages makes it an enzyme that has the most versatile α-hydrolytic activity among the 4mucosal α-glucosidases...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Michael J Lentze
The history of maltose-active disaccharidases is closely related to the history of the sugar and starch industry. It began in the 19th century, when a shortage of cane sugar occurred in continental Europe, because Napoleon Bonaparte decreed that no goods could be imported from England to the countries he occupied. Other sugar sources had to be found, and it led to the identification of sugar beets as alternative source of sugar by Marggraf in 1774, to the detection of starch hydrolysis by diluted sulfuric acid by Kirchhoff in 1812, and to the starch digestion enzyme, α-amylase, by Payen in 1833...
June 2018: Journal of Pediatric Gastroenterology and Nutrition
Kemin Tan, Christine Tesar, Rosemarie Wilton, Robert P Jedrzejczak, Andrzej Joachimiak
Carbohydrate hydrolyzing α-glucosidases are commonly found in microorganisms present in the human intestine microbiome. We have previously reported crystal structures of an α-glucosidase from the human gut bacterium Blaubia (Ruminococcus) obeum (Ro-αG1) and its substrate preference/specificity switch. This novel member of the GH31 family is a structural homolog of human intestinal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) with a highly conserved active site that is predicted to be common in Ro-αG1 homologs among other species that colonize the human gut...
May 15, 2018: Protein Science: a Publication of the Protein Society
Mikio Sugiki, Hiroyuki Miyakawa, Shoichi Tahara, Sumiyo Yamamoto, Narue Sakamaki, Yuki Sadamasu, Yoko Uematsu, Kimio Monma
A quantitative analysis by HPLC of α-glucosyltransferase-treated stevia in foods was considered. This analysis is the way which hydrolyzed α-glucosyltransferase-treated stevia in the stevioside (SS) and the rebaudioside A (RS) using a glucoamylase. Recovery (%) of α-glucosyltransferase-treated stevia, spiked at 200 mg/kg in various foods, were more than 80% and the relative standard deviations were less than 5.0% as SS and RS for the rate of collection. A qualitative analysis by LC-MS/MS was performed 36 products of commercial foods containing stevia...
2018: Shokuhin Eiseigaku Zasshi. Journal of the Food Hygienic Society of Japan
Christian Roth, Olga V Moroz, Antonio Ariza, Lars K Skov, Keiichi Ayabe, Gideon J Davies, Keith S Wilson
Glucoamylases are one of the most important classes of enzymes in the industrial degradation of starch biomass. They consist of a catalytic domain and a carbohydrate-binding domain (CBM), with the latter being important for the interaction with the polymeric substrate. Whereas the catalytic mechanisms and structures of the individual domains are well known, the spatial arrangement of the domains with respect to each other and its influence on activity are not fully understood. Here, the structures of three industrially used fungal glucoamylases, two of which are full length, have been crystallized and determined...
May 1, 2018: Acta Crystallographica. Section D, Structural Biology
Galimzhan Kalihanovich Duskaev, Nadezhda Mihajlovna Kazachkova, Alexander Sergeevich Ushakov, Baer Serekpaevich Nurzhanov, Albert Farhitdinovich Rysaev
Aim: Modern methods of producing poultry meat without the use of antibiotics are known, and it is possible to achieve the desired conditions, including the use of herbal preparations. In addition, it is known that metabolites of medicinal plants are inhibitors of the quorum sensing system in bacteria. The aim of the present study was to determine the effect of Quercus cortex extract in a reduced dose on the productivity and body state of healthy chicken broilers. Materials and Methods: For the experiment, 120 heads of 7-day-old healthy broiler chickens were selected, and they were divided into four groups (n=30, 3 replicates of 10 birds in each group) by the analog method...
February 2018: Veterinary World
Tahmina Hossain, Abdul Bathen Miah, Siraje Arif Mahmud, Abdullah-Al- Mahin
In this study, an extensive screening was undertaken to isolate some amylolytic microorganisms capable of producing bioethanol from starchy biomass through Consolidated Bioprocessing (CBP). A total of 28 amylolytic microorganisms were isolated, from which 5 isolates were selected based on high α-amylase and glucoamylase activities and identified as Candida wangnamkhiaoensis, Hyphopichia pseudoburtonii (2 isolates), Wickerhamia sp., and Streptomyces drozdowiczii based on 26S rDNA and 16S rDNA sequencing. Wickerhamia sp...
April 12, 2018: Applied Biochemistry and Biotechnology
Hong Jiang, Si-Jia Xue, Yan-Feng Li, Guang-Lei Liu, Zhen-Ming Chi, Zhong Hu, Zhe Chi
A very high pullulan producing yeast-like fungus, Aureobasidium melanogenum TN1-2 isolated from a natural honey was found to be able to produce 97.0 g/L of pullulan from 140.0 g/L sucrose at a flask level while it could yield 114.0 g/L of pullulan within 134 h during a 10-liter fermentation, the yield was 0.81 g/g and the productivity was 0.86 g/L/h. The high ability to biosynthesize pullulan by this yeast-like fungal strain TN1-2 was related to high glucosyltransferase activity, high phosphofructo-2-kinase activity, high content of its cellular glycerol and low glucose repressor...
August 15, 2018: Food Chemistry
Yue Xu, Yan-Hui Wang, Tian-Qi Liu, Hui Zhang, He Zhang, Jie Li
OBJECTIVE: α-Galactosidases are widely used in many fields. It is necessary to improve the production of enzymes through microbiological processes. The aim of this study was to construct recombinant Aspergillus niger strains with high α-galactosidase production. RESULTS: Two recombinant A. niger strains were constructed: AB and AGB. The recombinant AB strain contained the α-galactosidase aglB gene from A. niger with its native AglB signal peptide regulated by the glucoamylase promoter...
June 2018: Biotechnology Letters
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