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Thiago Machado Pasin, Vivian Machado Benassi, Paulo Ricardo Heinen, André Ricardo de Lima Damasio, Mariana Cereia, João Atílio Jorge, Maria de Lourdes Teixeira de Moraes
Microbial amylases are used to produce ethanol, glucose and can be applied in textiles products, detergents and other industries. This study aimed to determine the best carbon source concentration to induce the amylase production by A. japonicus, and its purification and biochemical characterization. For that, this fungus was cultivated in Khanna medium, pH 5.5, for 4 days, at 25°C, in static condition, supplemented with potato starch and maltose in different concentrations. The fungal crude enzymatic extract was purified in a unique elution in DEAE-cellulose column and the molecular mass was determined as 72kDa...
April 12, 2017: International Journal of Biological Macromolecules
Baoshi Wang, Hua Li, Linghuan Zhu, Fengling Tan, Youran Li, Liang Zhang, Zhongyang Ding, Guiyang Shi
Citric acid (CA), an important platform-compound, has attracted much attention because of its broad applications and huge market demand. To solve high residual sugar at the fermentation end, we put forwarded strategy of pre-saccharification and then fermentation. Results showed that the residual total sugar decreased by 10.4% and the productivity increased by 4.0% and initially high glucose inhibited cell growth. Furthermore, commercial glucoamylase with high low-pH stability was proposed to staged-add in the fermentation process, which timely compensated enzyme loss, ensuring the glucose supply rate...
April 7, 2017: Bioprocess and Biosystems Engineering
Peng Wang, Qun Wu, Xuejian Jiang, Zhiqiang Wang, Jingli Tang, Yan Xu
Chinese liquor is produced from spontaneous fermentation starter (Daqu) that provides the microbes, enzymes and flavors for liquor fermentation. To improve the flavor character of Daqu, we inoculated Bacillus licheniformis and studied the effect of this strain on the community structure and metabolic profile in Daqu fermentation. The microbial relative abundance changed after the inoculation, including the increase in Bacillus, Clavispora and Aspergillus, and the decrease in Pichia, Saccharomycopsis and some other genera...
March 14, 2017: International Journal of Food Microbiology
M F Fernandez-Alarcon, N Trottier, J P Steibel, R Lunedo, D M B Campos, A M Santana, J M Pizauro, R L Furlan, L R Furlan
The objectives of this study were to describe alterations that age and dietary inclusion of direct-fed microbial (DFM) Bacillus subtilis (BS) and a specific essential oil (EO) blend (carvacrol, cinnamaldehyde, cineol, and pepper extract) causes in the activity of digestive enzymes (maltase: MALT; aminopeptidase-N: APN; intestinal alkaline phosphate: IAP) and expression patterns of genes related to transport (oligopeptide transporter gene: SLC15A1; Na+-dependent glucose and galactose transporter gene: SLC5A1; Na+-independent glucose, galactose, and fructose transporter gene: SLC2A2; ATPase, Na+/K+ transporting gene: ATP1A1) and digestion (aminopeptidase-N gene: ANPEP; maltase-glucoamylase gene: MGAM; Sucrase-isomaltase gene: SI) of carbohydrates and proteins in the small intestine of broilers...
February 23, 2017: Poultry Science
Fadia S Youssef, Mohamed L Ashour, Sherif S Ebada, Mansour Sobeh, Hesham A El-Beshbishy, Abdel Nasser Singab, Michael Wink
OBJECTIVES: This study was designed to evaluate the antihyperglycaemic activity of the methanol leaf extract of Eremophila maculata (EMM) both in vitro and in vivo. METHODS: The antihyperglycaemic activity was assessed in vitro using differentiated 3T3-L1 adipocytes, whereas in-vivo effect was evaluated in streptozotocin-induced diabetic rats. Chemical profiling of EMM was done using LC-ESI-MS techniques. Molecular modelling experiments of the identified compounds were performed using C-Docker protocol...
March 21, 2017: Journal of Pharmacy and Pharmacology
Buford L Nichols, Stephen E Avery, Roberto Quezada-Calvillo, Shadi B Kilani, Amy Hui-Mei Lin, Douglas G Burrin, Benjamin E Hodges, Shaji K Chacko, Antone R Opekun, Marwa El Hindawy, Bruce R Hamaker, Sen-Ichi Oda
Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with Congenital Sucrase-isomaltase Deficiency (CSID). BACKGROUND: Starch digestion is much more complex than sucrose digestion. Six enzyme activities, two α-amylases (Amy) and four mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose...
March 6, 2017: Journal of Pediatric Gastroenterology and Nutrition
Albrecht Läufer
Nature uses enzymes to build and convert biomass; mankind uses the same enzymes and produces them on a large scale to make optimum use of biomass in biorefineries. Bacterial α-amylases and fungal glucoamylases have been the workhorses of starch biorefineries for many decades. Pullulanases were introduced in the 1980s. Proteases, cellulases, hemicellulases, and phytases have been on the market for a few years as process aids, improving yields, performance, and costs. Detailed studies of the complex chemical structures of biomass and of the physicochemical limitations of industrial biorefineries have led enzyme developers to produce novel tailor-made solutions for improving yield and profitability in the industry...
March 7, 2017: Advances in Biochemical Engineering/biotechnology
Ye-Seul Koo, Dam-Seul Ko, Da-Woon Jeong, Jae-Hoon Shim
Cyclodextrins (CDs) are produced from starch by cyclodextrin glucanotransferase (CGTase), which has cyclization activity. Specifically, α-CD is an important biomolecule, as it is a molecular carrier and soluble dietary fiber used in the food industry. Upon inspection of the conserved regions of the glycoside hydrolase (GH) 13 family amylases, the amino acids K232 and H233 of CGTase were identified as playing an important role in enzyme reaction specificity. A novel CD hydrolyzing enzyme, cyclodextrin glycosyl transferase (CGTase)-alpha, was developed using site-directed mutagenesis at these positions...
March 7, 2017: Journal of Agricultural and Food Chemistry
Deepak Parashar, T Satyanarayana
For saccharifying starch in one step, a chimeric biocatalyst (Amy-Glu) was generated from engineered α-amylase (Ba-Gt-amy) of Bacillus acidicola and glucoamylase (Glu) gene of Aspergillus niger. In order to join two enzymes, a linker peptide of 25 amino acids was used. Chimeric Amy-Glu was expressed in E. coli. Glu is of 75kDa, while Amy-Glu is of 145kDa. Both Amy-Glu and Glu displayed similar pH profile with good activity in the acidic pH range like that of Ba-Gt-amy with optimum at pH 4.0. All three enzymes (Ba-Gt-amy, Amy-Glu and glucoamylase) exhibited activity in the temperature range between 40 and 70°C with optimum at 60°C...
June 2017: International Journal of Biological Macromolecules
Jang-Eun Lee, Ae Ran Lee, HyeRyun Kim, Eunjung Lee, Tae Wan Kim, Woo Chang Shin, Jae Ho Kim
In this study, a total of 58 different kinds of traditional Nuruk were prepared, including 46 kinds of restored Nuruk from ancient documents. Each Nuruk was evaluated by analysis of saccharification power, and the enzyme activities of glucoamylase, α-amylase, β-amylase, protease, and β-glucanase. The range of saccharification power of the restored Nuruk ranged between was 85 and 565 sp. The diastatic enzymes, α-amylase, β-amylase and glucoamylase were significantly correlated to saccharification power value conversely β-glucanase and protease did not have a correlative relationship with saccarification power...
February 24, 2017: Journal of Microbiology and Biotechnology
Rémi Dulermo, François Brunel, Thierry Dulermo, Rodrigo Ledesma-Amaro, Jérémy Vion, Marion Trassaert, Stéphane Thomas, Jean-Marc Nicaud, Christophe Leplat
BACKGROUND: The yeast Yarrowia lipolytica is an increasingly common biofactory. To enhance protein expression, several promoters have been developed, including the constitutive TEF promoter, the inducible POX2 promotor, and the hybrid hp4d promoter. Recently, new hp4d-inspired promoters have been created that couple various numbers of UAS1 tandem elements with the minimal LEU2 promoter or the TEF promoter. Three different protein-secretion signaling sequences can be used: preLip2, preXpr2, and preSuc2...
February 17, 2017: Microbial Cell Factories
Xudong Zhu, Bessembayev Arman, Ju Chu, Yonghong Wang, Yingping Zhuang
OBJECTIVES: To develop an efficient cost-effective screening process to improve production of glucoamylase in Aspergillus niger. RESULTS: The cultivation of A. niger was achieved with well-dispersed morphology in 48-deep-well microtiter plates, which increased the throughput of the samples compared to traditional flask cultivation. There was a close negative correlation between glucoamylase and its pH of the fermentation broth. A novel high-throughput analysis method using Methyl Orange was developed...
January 30, 2017: Biotechnology Letters
Minhal Abidi, Afshin Iram, Mohammad Furkan, Aabgeena Naeem
Glucoamylase (EC from Aspergillus niger possesses 31% α-helix, 36% β structure and rest aperiodic structure. A transition of glucoamylase structure in the presence of varying concentrations of glyoxal (GO) and trifluoroethanol (TFE) was studied by using multi-methodological approaches. At 20% GO, glucoamylase exists as molten globule state as evident by high tryptophan and ANS fluorescence, retention of secondary structure and loss of native tertiary structure. This state precedes the onset of the aggregation process and maximum is achieved at the highest concentration i...
May 2017: International Journal of Biological Macromolecules
Alexander G Bulakhov, Pavel V Volkov, Aleksandra M Rozhkova, Alexander V Gusakov, Vitaly A Nemashkalov, Aidar D Satrutdinov, Arkady P Sinitsyn
BACKGROUND: Penicillium verruculosum is an efficient producer of highly active cellulase multienzyme system. One of the approaches for enhancing cellulase performance in hydrolysis of cellulosic substrates is to enrich the reaction system with β -glucosidase and/or accessory enzymes, such as lytic polysaccharide monooxygenases (LPMO) displaying a synergism with cellulases. RESULTS: Genes bglI, encoding β-glucosidase from Aspergillus niger (AnBGL), and eglIV, encoding LPMO (formerly endoglucanase IV) from Trichoderma reesei (TrLPMO), were cloned and expressed by P...
2017: PloS One
Haiyan Sun, Ming Peng
OBJECTIVES: To investigate the role of maltose stearic acid ester (MSAE) for improving raw-starch-digesting glucoamylase (RSDG) production by Aspergillus niger F-01 and its regulatory mechanism. RESULTS: RSDG activity was enhanced 8.3-fold by adding 5 g MSAE to 1 l basal medium at the beginning of the culture. RSDG biosynthesis nearly ceased by adding 100 μg actinomycin D/ml or 50 μg cycloheximide/ml in a 48 h culture in the basal medium. RSDG biosynthesis was restarted by adding MSAE in the culture repressed by actinomycin D...
April 2017: Biotechnology Letters
Masayoshi Sakaguchi, Yudai Matsushima, Yusuke Nagamine, Tomoki Matsuhashi, Shotaro Honda, Shoi Okuda, Misa Ohno, Yasusato Sugahara, Yongchol Shin, Fumitaka Oyama, Masao Kawakita
Clostridium sp. G0005 glucoamylase (CGA) is composed of a β-sandwich domain (BD), a linker, and a catalytic domain (CD). In the present study, CGA was expressed in Escherichia coli as inclusion bodies when the N-terminal region (39 amino acid residues) of the BD was truncated. To further elucidate the role of the N-terminal region of the BD, we constructed N-terminally truncated proteins (Δ19, Δ24, Δ29, and Δ34) and assessed their solubility and activity. Although all evaluated proteins were soluble, their hydrolytic activities toward maltotriose as a substrate varied: Δ19 and Δ24 were almost as active as CGA, but the activity of Δ29 was substantially lower, and Δ34 exhibited little hydrolytic activity...
March 2017: Applied Microbiology and Biotechnology
Wei Han, Yingting Yan, Yiwen Shi, Jingjing Gu, Junhong Tang, Hongting Zhao
In this study, the feasibility of biohydrogen production from enzymatic hydrolysis of food waste was investigated. Food waste (solid-to-liquid ratio of 10%, w/v) was first hydrolyzed by commercial glucoamylase to release glucose (24.35 g/L) in the food waste hydrolysate. Then, the obtained food waste hydrolysate was used as substrate for biohydrogen production in the batch and continuous (continuous stirred tank reactor, CSTR) systems. It was observed that the maximum cumulative hydrogen production of 5850 mL was achieved with a yield of 245...
December 2, 2016: Scientific Reports
Shamraja S Nadar, Virendra K Rathod
The self-assembled glucoamylase metal-organic framework (glucoamylase-MOF) was synthesized by facile one-step method within 20min by simply mixing aqueous solution of 2-methylimidazole (160mM), glucoamylase (5mg/mL) and zinc acetate (40mM) at room temperature (28±2°C). The prepared glucoamylase-MOF was characterized by using FT-IR, confocal scanning laser microscopy, XRD and SEM. The robustness and thermal stability of glucoamylase embedded MOF was evaluated in terms of half-life (in the range of 60-80°C) which showed 6 folds increment as against free form...
February 2017: International Journal of Biological Macromolecules
Deepak Kumar, Vijay Singh
BACKGROUND: Conventional corn dry-grind ethanol production process requires exogenous alpha and glucoamylases enzymes to breakdown starch into glucose, which is fermented to ethanol by yeast. This study evaluates the potential use of new genetically engineered corn and yeast, which can eliminate or minimize the use of these external enzymes, improve the economics and process efficiencies, and simplify the process. An approach of in situ ethanol removal during fermentation was also investigated for its potential to improve the efficiency of high-solid fermentation, which can significantly reduce the downstream ethanol and co-product recovery cost...
2016: Biotechnology for Biofuels
Jyotiranjan Bal, Suk-Hyun Yun, Jeesun Chun, Beom-Tae Kim, Dae-Hyuk Kim
The most economically important species used in a wide range of fermentation industries throughout Asia belong to Aspergillus section Flavi, which are morphologically and phylogenetically indistinguishable, with a few being toxigenic and therefore a major concern. They are frequently isolated from Korean fermentation starters, such as nuruk and meju. The growing popularity of traditional Korean alcoholic beverages has led to a demand for their quality enhancement, therefore requiring selection of efficient non-toxigenic strains to assist effective fermentation...
September 2016: Mycobiology
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