Journal articles on the topic 'Amylases'
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1
Sachdev, Shivani, Sanjay Kumar Ojha, and Snehasish Mishra. "Bacillus Spp. Amylase: Production, Isolation, Characterisation and Its Application." International Journal of Applied Sciences and Biotechnology 4, no. 1 (March 31, 2016): 3–14. http://dx.doi.org/10.3126/ijasbt.v4i1.14574.
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Amylase is one of the leading enzymes used in industry from decades. The preliminary function of this enzyme is the hydrolysis of the starch molecule into glucose units and oligosaccharides. Amylases have spectacular application in broad spectrum of industries such as food, detergent, pharmaceutical and fermentation industries. Among different type of amylases α- amylase is in utmost demand because of its striking features. This particular enzyme is a good substitute over the chemicals catalyst used in industries. α- amylases can be acquired from different sources such as microorganism, animals and plants. Microorganisms are the major source of production of amylase because of the ease of availability, manipulation and operation. The starch converting enzymes is basically generated using submerged fermentation. Some of the prominent characteristics of amylase are its mode of action, substrate specificity and operating condition (temperature and pH). Amylases from different bacterial sources contribute differently to the particular trait of the enzyme. Bacillus amylases have been studied and applied so far because of their robustness in nature and easy accessible pure form of it. Thus this makes it more specific and fit for distinct application in the industry. The purpose of this manuscript was the comparative analysis of the physical and chemical features of α amylases from Bacillus species. It also focuses on the unique characteristics of this enzyme and their industrial applications.Int J Appl Sci Biotechnol, Vol 4(1): 3-14
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Janeček, Štefan. "Amylolytic enzymes - focus on the alpha-amylases from Archae and plants." Nova Biotechnologica et Chimica 9, no. 1 (November 29, 2021): 5–26. http://dx.doi.org/10.36547/nbc.1284.
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Amylolytic enzymes represent a group of starch hydrolases and related enzymes that are active towards the α-glycosidic bonds in starch and related poly- and oligosaccharides. The three best known amylolytic enzymes are α-amylase, β-amylase and glucoamylase that, however, differ from each other by their amino acid sequences, three-dimensional structures, reaction mechanisms and catalytic machineries. In the sequence-based classification of all glycoside hydrolases (GHs) they have therefore been classified into the three independent families: GH13 (α-amylases), GH14 (β-amylases) and GH15 (glucoamylases). Some amylolytic enzymes have been placed to the families GH31 and GH57. The family GH13 together with the families GH70 and GH77 constitutes the clan GH-H, well-known as the α-amylase family. It contains more than 6,000 sequences and covers 30 various enzyme specificities sharing the conserved sequence regions, catalytic TIM-barrel fold, retaining reaction mechanism and catalytic triad. Among the GH13 α-amylases, those produced by plants and archaebacteria exhibit common sequence similarities that distinguish them from the α-amylases of the remaining taxonomic sources. Despite the close evolutionary relatedness between the plant and archaeal α-amylases, there are also specific differences that discriminate them from each other. These specific differences could be used in an effort to reveal the sequence-structural features responsible for the high thermostability of the α-amylases from Archaea.
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Türker, Celal, and Bahri Devrim Özcan. "Alfa-amilaz Enzimlerini Üreten Termofilik Bacillus Suşlarının İzolasyonu ve Enzimlerin Kısmi Karakterizasyonu." Turkish Journal of Agriculture - Food Science and Technology 3, no. 6 (March 7, 2015): 387. http://dx.doi.org/10.24925/turjaf.v3i6.387-393.312.
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In the present study, we isolated three thermophilic Bacillus strains from the soil samples collected from the coast sediments of the Burnaz Stream located in Erzin. The isolates were entitled as Bacillus sp. CT1, CT2, and CT3, respectively. The maximum α-amylase production was revealed at 60°C for CT1 strain, and at 80°C for CT2 and CT3 strains, respectively. The optimum enzyme activity was observed at 90°C for CT1 α-amylase, whereas at 60°C for CT2 and CT3 α-amylases. On the other hand, optimum pH value for CT2 α-amylase was 7.0, whereas 8.0 for CT1 and CT3 α-amylases. The specific activities of CT1, CT2, and CT3 amylases were 317.6, 113.3 and 362.7 U/mg at 55°C, respectively. The estimated molecular weight of CT1 and CT3 α-amylase was 65 kDa, and for CT2 α-amylase was 38 kDa by zymogram analysis.
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Sondhi, Sonica, Palki Sahib Kaur, Himansi Sura, Manisha Juglani, and Deepali Sharma. "Amylase Based Clarification of Apple, Orange and Grape Juice." CGC International Journal of Contemporary Technology and Research 3, no. 2 (July 17, 2021): 187–90. http://dx.doi.org/10.46860/cgcijctr.2021.06.31.187.
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Amylases are starch-degrading enzymes produced by many bacteria, plants, fungi and animals. It has found tremendous application in industry. One of its applications is in fruit industry wherein amylases are used to clarify fruit juices and reduce its viscosity. In fruits, high amount of starch is present which resulted in increased viscosity of the prepared juices. This may also lead to settling of juice at bottom. Amylases act on starch component and degrade it. In the current study, amylase from B. licheniformis was used for the clarification of apple, orange and grape juices. Total suspended solids, viscosity and total acidity was found to decrease with increasing amylase concentration. The results revealed that after amylase treatment the color, texture and flavor of juices were also improved.
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Roth, Christian, Olga V. Moroz, Johan P. Turkenburg, Elena Blagova, Jitka Waterman, Antonio Ariza, Li Ming, et al. "Structural and Functional Characterization of Three Novel Fungal Amylases with Enhanced Stability and pH Tolerance." International Journal of Molecular Sciences 20, no. 19 (October 3, 2019): 4902. http://dx.doi.org/10.3390/ijms20194902.
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Amylases are probably the best studied glycoside hydrolases and have a huge biotechnological value for industrial processes on starch. Multiple amylases from fungi and microbes are currently in use. Whereas bacterial amylases are well suited for many industrial processes due to their high stability, fungal amylases are recognized as safe and are preferred in the food industry, although they lack the pH tolerance and stability of their bacterial counterparts. Here, we describe three amylases, two of which have a broad pH spectrum extending to pH 8 and higher stability well suited for a broad set of industrial applications. These enzymes have the characteristic GH13 α-amylase fold with a central (β/α)8-domain, an insertion domain with the canonical calcium binding site and a C-terminal β-sandwich domain. The active site was identified based on the binding of the inhibitor acarbose in form of a transglycosylation product, in the amylases from Thamnidium elegans and Cordyceps farinosa. The three amylases have shortened loops flanking the nonreducing end of the substrate binding cleft, creating a more open crevice. Moreover, a potential novel binding site in the C-terminal domain of the Cordyceps enzyme was identified, which might be part of a starch interaction site. In addition, Cordyceps farinosa amylase presented a successful example of using the microseed matrix screening technique to significantly speed-up crystallization.
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Melo, Francislete R., Mauricio P. Sales, Lucilene S. Pereira, Carlos Bloch, Octavio L. Franco, and Maria B. Ary. "α-Amylase Inhibitors from Cowpea Seeds." Protein & Peptide Letters 6, no. 6 (December 1999): 385–90. http://dx.doi.org/10.2174/092986650606221117144709.
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Abstract: This work describes the first isolation and partial characterization of α-amylase inhibitors from cowpea (Vigna unguiculata) seeds. α-Amylase inhibitors were isolated using an affinity chromatography on Red Sepharose CL-6B. The bound Red Sepharose fraction was active against α-amylases from Bacillus sp., Aspergilus oryzae, V unguicu/ata seeds and also against α-amylases from Callosobruchus maculatus larvae.
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Garba, L., M. M. Ibrahim, E. K. Sahara, M. T. Adamu, S. Isa, and A. A. Yarma. "Preliminary Investigation of Amylase Producing-Bacteria from Soil in Gombe Metropolis." Journal of Environmental Bioremediation and Toxicology 4, no. 1 (July 30, 2021): 1–3. http://dx.doi.org/10.54987/jebat.v4i1.576.
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Amylases are enzymes that are able to hydrolyse starch or glycogen molecules into polymers of glucose units. They have great potential applications in various industrial processes like in pharmaceutical, fermentation and food industries. Research on starch degrading enzymes has resulted into increased applications of amylases in different industrial processes. These enzymes occupy a greater space in the current biotechnological processes such as detergent, starch degradation, pharmaceutical, foodstuff, textile, and paper manufacturing. In fact, amylases constitute nearly 25% of the total sale of global enzymes. Amylases have been screened and identified from various sources, both eukaryotic and prokaryotic organisms such as animals, plants, fungi and bacteria, respectively. To further isolate novel amylases with enhanced desirable properties for such diverse industrial application, more organisms need to be screened. In this study, a total of 27 bacterial isolates were isolated from soil samples in Gombe metropolis. The bacteria were screened for amylase production using plate screening method. Each isolate was streaked onto a 1% starch agar plate and incubated for 24h at 37 °C. The plates were covered with iodine solution and observed for positive amylase isolates based on the formation of clearing zones against the blue black background. The results confirmed eight (8) isolates of amylase-producing bacteria which include Bacillus subtilis, Escherichia coli, Streptococcus spp., Salmonella spp., Pseudomonas spp., Serratia spp., Proteus vulgaris, and Klebsiella spp. In conclusion, bacterial isolates capable of amylase production have been successfully screened and identified. This research may serve as a stepping stone to isolating functional amylase enzymes from these bacteria for promising industrial applications.
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Marengo, Mauro, Davide Pezzilli, Eleonora Gianquinto, Alex Fissore, Simonetta Oliaro-Bosso, Barbara Sgorbini, Francesca Spyrakis, and Salvatore Adinolfi. "Evaluation of Porcine and Aspergillus oryzae α-Amylases as Possible Model for the Human Enzyme." Processes 10, no. 4 (April 15, 2022): 780. http://dx.doi.org/10.3390/pr10040780.
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α-amylases are ubiquitous enzymes belonging to the glycosyl hydrolase (GH13) family, whose members share a high degree of sequence identity, even between distant organisms. To understand the determinants of catalytic activity of α-amylases throughout evolution, and to investigate the use of homologous enzymes as a model for the human one, we compared human salivary α-amylase, Aspergillus oryzae α-amylase and pancreatic porcine α-amylase, using a combination of in vitro and in silico approaches. Enzyme sequences were aligned, and structures superposed, whereas kinetics were spectroscopically studied by using commercial synthetic substrates. These three enzymes show strikingly different activities, specifically mediated by different ions, despite relevant structural homology. Our study confirms that the function of α-amylases throughout evolution has considerably diverged, although key structural determinants, such as the catalytic triad and the calcium-binding pocket, have been retained. These functional differences need to be carefully considered when α-amylases, from different organisms, are used as a model for the human enzymes. In this frame, particular focus is needed for the setup of proper experimental conditions.
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Urdal, P., S. Landaas, P. Kierulf, and J. H. Strømme. "Macroamylase immunoglobulins show high affinity for animal and human amylases." Clinical Chemistry 31, no. 5 (May 1, 1985): 699–702. http://dx.doi.org/10.1093/clinchem/31.5.699.
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Abstract We have examined the affinity shown by the immunoglobulin fraction from each of five sera containing macroamylase for amylases from different sources: human saliva or human, porcine, or ovine pancreas. High affinity constants, 0.4 X 10(10) to 7.2 X 10(10) L/mol, were found in competitive binding experiments with human or porcine pancreatic amylase. All but one serum yielded linear Scatchard plots, indicating that in most sera the amylase-binding immunoglobulins are homogeneous, possibly monoclonal. The immunoglobulin fractions from different sera differed in their specificity: two of them bound all four types of amylases, whereas two bound only one type. Three of the five immunoglobulin fractions showed considerably higher affinity towards one or both of the animal amylases than towards the human ones, and may be primarily directed against some animal amylase.
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Domingues, Claudia M., and Rosane M. Peralta. "Production of amylase by soil fungi and partial biochemical characterization of amylase of a selected strain (Aspergillus fumigatus Fresenius)." Canadian Journal of Microbiology 39, no. 7 (July 1, 1993): 681–85. http://dx.doi.org/10.1139/m93-098.
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Filamentous fungi from soil were screened for their ability to produce amylases in semisolid and liquid media with wheat bran. A selected strain identified as Aspergillus fumigatus Fresenius showed high enzymatic activity for α-amylase and glucoamylase. The maximal yield of these amylases was obtained when lignocellulosic materials were the carbon sources. The optimal pH and temperature were 6.0 and 50 °C, respectively, for both enzymes. α-Amylase activity was more thermostable than glucoamylase activity.Key words: amylolitic fungi, α-amylase, glucoamylase, Aspergillus fumigatus.
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Mitsui, Toshiaki, Akihito Ochiai, Hiromoto Yamakawa, Kentaro Kaneko, Aya Kitajima-Koga, and Marouane Baslam. "Novel molecular and cell biological insights into function of rice α-amylase." Amylase 2, no. 1 (July 1, 2018): 30–38. http://dx.doi.org/10.1515/amylase-2018-0004.
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Abstract α-Amylases have been of interest in diverse fields for many years because of their importance in basic biology, agriculture, and industry. Starch hydrolysis in plants has been studied extensively in germinating cereal seeds. It is generally accepted that α-amylases are secretory enzymes with a pivotal role in the breakdown of starch reserves in the endosperm. Intriguingly, however, recent investigations reveal that some α-amylases degrade starch in the plastids of living cells. The recent solving of the crystal structure of rice AmyI-1 isoform shows that the binding pocket of starch binding site 1 situated outside of the active site cleft interacts with the substances other than oligosaccharides. These findings provided novel insights into structural and cell biological aspects of α-amylase functions in intracellular transport, organelle targeting, and organ-specific actions. Under global warming, abnormal high temperatures during rice grain filling increase grain chalkiness, resulting in yield loss. Intensive “omics” analyses of developing caryopses and mature grains grown under heat stress showed the downregulation of starch synthesis enzymes and the upregulation of α-amylases. Transgenic studies using ectopic overexpression and suppression of α-amylase revealed that α-amylase is a key factor in grain chalkiness. Here we discuss unique new functions of α-amylase in rice cells.
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Lahmar, Imen, Hanen El Abed, Bassem Khemakhem, Hafedh Belghith, Ferjani Ben Abdallah, and Karima Belghith. "Optimization, Purification, and Starch Stain Wash Application of Two Newα-Amylases Extracted from Leaves and Stems ofPergularia tomentosa." BioMed Research International 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/6712742.
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A continuous research is attempted to fulfil the highest industrial demands of natural amylases presenting special properties. Newα-amylases extracted from stems and leaves ofPergularia tomentosa, which is widespread and growing spontaneously in Tunisia, were studied by the means of their activities optimization and purification. Some similarities were recorded for the two identified enzymes: (i) the highest amylase activity showed a promoted thermal stability at 50°C; (ii) the starch substrate at 1% enhanced the enzyme activity; (iii) the twoα-amylases seem to be calcium-independent; (iv) Zn2+, Cu2+, and Ag2+were considered as important inhibitors of the enzyme activity. Following the increased gradient of elution on Mono Q-Sepharose column, an increase in the specific activity of 11.82-fold and 10.92-fold was recorded, respectively, for leaves and stems with the presence of different peaks on the purification profiles.Pergulariaamylases activities were stable and compatible with the tested commercial detergents. The combination of plant amylase and detergent allowed us to enhance the wash performance with an increase of 35.24 and 42.56%, respectively, for stems and leaves amylases. Characterized amylases were reported to have a promoted potential for their implication notably in detergent industry as well as biotechnological sector.
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Darvishzadeh, A., A. Bandani, and S. Q. Mousavi. "Biochemical characterisation of α-amylase in two aphid species, Aphis fabae Scopoli (Hemiptera: Aphididae) and A. gossypii Glover (Hemiptera: Aphididae)." Plant Protection Science 50, No. 2 (May 6, 2014): 84–89. http://dx.doi.org/10.17221/71/2012-pps.
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We identify and characterise α-amylases of the two aphid species, A. fabae and A. gossypi. To do this, α-amylases of the two insect species were extracted and their activities were determined using 1% soluble starch. Results showed that α-amylase, which hydrolyses starch, is present in both aphids. Also, it was shown that optimum pH and temperature for the α-amylases of both species is 7.0 and 40°C, respectively. Gel assays using zymogram analysis showed that in both aphid species more than one isoform (two isoforms) of α-amylases hydrolyszing carbohydrates are present.
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Reddy, M. K., G. D. Heda, and J. K. Reddy. "Purification and characterization of α-amylase from rat pancreatic acinar carcinoma. Comparison with pancreatic α-amylase." Biochemical Journal 242, no. 3 (March 15, 1987): 681–87. http://dx.doi.org/10.1042/bj2420681.
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alpha-Amylase was purified to apparent homogeneity from normal pancreas and a transplantable pancreatic acinar carcinoma of the rat by affinity chromatography on alpha-glucohydrolase inhibitor (alpha-GHI) bound to aminohexyl-Sepharose 4B. Recovery was 95-100% for both pancreas and tumour alpha-amylases. They were monomeric proteins, with Mr approx. 54000 on SDS/polyacrylamide-gel electrophoresis. Isoelectric focusing of both normal and tumour alpha-amylases resolved each into two major isoenzymes, with pI 8.3 and 8.7. Tumour-derived alpha-amylase contained two additional minor isoenzymes, with pI 7.6 and 6.95 respectively. All four tumour isoenzymes demonstrated amylolytic activity when isoelectric-focused gels were treated with starch and stained with iodine. Two-dimensional electrophoresis, on SDS/10-20%-polyacrylamide-gradient gels after isoelectric focusing, separated each major isoenzyme into doublets of similar Mr values. Pancreatic and tumour-derived alpha-amylases had similar Km and Ki (alpha-GHI) values, but the specific activity of the tumour alpha-amylase was approximately two-thirds that of the normal alpha-amylase. Although amino acid analysis and peptide mapping with the use of CNBr, N-chlorosuccinimide or Staphylococcus aureus V8 proteinase gave comparable profiles for the two alpha-amylases, tryptic-digest fingerprint patterns were different. Antibodies raised against the purified pancreatic alpha-amylase and tumour alpha-amylase respectively showed only one positive band on immunoblotting after gel electrophoresis of crude extracts of rat pancreas and carcinoma, at the same position as that of the purified enzyme. More than 95% of the alpha-amylase activity in the pancreas and in the tumour was absorbed by an excess amount of either antibody, indicating that normal and tumour alpha-amylases are immunologically identical. The presence of additional isoenzymes in the carcinoma, and dissimilarity of tryptic-digest patterns, may reflect an alteration in gene expression or in the post-translational modification of this protein in this heterogeneously differentiated transplantable pancreatic acinar carcinoma.
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Sokarda-Slavic, Marinela, Natasa Bozic, and Z. Vujcic. "Growth temperature of different local isolates of Bacillus sp. in the solid state affects production of raw starch digesting amylases." Archives of Biological Sciences 66, no. 2 (2014): 483–90. http://dx.doi.org/10.2298/abs1402483s.
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Natural amylase producers, wild type strains of Bacillus sp., were isolated from different regions of Serbia. Strains with the highest amylase activity based on the starch-agar plate test were grown on solid-state fermentation (SSF) on triticale. The influence of the substrate and different cultivation temperature (28 and 37?C) on the production of amylase was examined. The tested strains produced ?-amylases when grown on triticale grains both at 28 and at 37?C, but the activity of amylases and the number and intensity of the produced isoforms were different. Significant hydrolysis of raw cornstarch was obtained with the Bacillus sp. strains 2B, 5B, 18 and 24B. The produced ?-amylases hydrolyzed raw cornstarch at a temperature below the temperature of gelatinization, but the ability for hydrolysis was not directly related to the total enzyme activity, suggesting that only certain isoforms are involved in the hydrolysis.
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Zółtowska, K. "Purification and characterization of alpha-amylases from the intestine and muscle of ascaris suum (Nematoda)." Acta Biochimica Polonica 48, no. 3 (September 30, 2001): 763–74. http://dx.doi.org/10.18388/abp.2001_3911.
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Alpha-Amylase (EC 3.2.1.1) was purified from the muscle and intestine of the parasitic helminth of pigs Ascaris suum. The enzymes from the two sources differed in their properties. Isoelectric focusing revealed one form of a-amylase from muscles with pl of 5.0, and two forms of amylase from intestine with pI of 4.7 and 4.5. SDS/PAGE suggested a molecular mass of 83 kDa and 73 kDa for isoenzymes of a-amylases from intestine and 59 kDa for the muscle enzyme. Alpha-Amylase from intestine showed maximum activity at pH 7.4, and the enzyme from muscle at pH 8.2. The muscle enzyme was more thermostabile than the intestinal alpha-amylase. Both the muscle and intestine amylase lost half of its activity after 15 min at 70 degrees C and 50 degrees C, respectively. The Km values were: for muscle amylase 0.22 microg/ml glycogen and 3.33 microg/ml starch, and for intestine amylase 1.77 microg/ml glycogen and 0.48 microg/ml starch. Both amylases were activated by Ca2+ and inhibited by EDTA, iodoacetic acid, p-chloromercuribenzoate and the inhibitor of a-amylase from wheat. No significant differences were found between the properties of a-amylases from parasites and from their hosts.
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Linardi, Valter R., and Katia M. G. Machado. "Production of amylases by yeasts." Canadian Journal of Microbiology 36, no. 11 (November 1, 1990): 751–53. http://dx.doi.org/10.1139/m90-129.
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Yeasts (228) isolated for natural habitats were screened for their ability to produce amylases in semisolid medium of wheat bran. Strains of Aureobasidium pullulans, Candida famata, and Candida kefyr showed high enzymatic activity for α-amylase, glucoamylase, and debranching enzyme. Key words: Aureobasidium, Candida, amylolytic yeasts, α-amylase, glucoamylase.
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Silva, Maria Cristina Mattar da, Luciane Vieira Mello, Marise Ventura Coutinho, Daniel John Rigden, Goran Neshich, Maarten John Chrispeels, and Maria Fátima Grossi-de-Sá. "Mutants of common bean alpha-amylase inhibitor-2 as an approach to investigate binding specificity to alpha-amylases." Pesquisa Agropecuária Brasileira 39, no. 3 (March 2004): 201–8. http://dx.doi.org/10.1590/s0100-204x2004000300001.
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Despite the presence of a family of defense proteins, Phaseolus vulgaris can be attacked by bruchid insects resulting in serious damage to stored grains. The two distinct active forms of a-amylase inhibitors, a-AI1 and a-AI2, in P. vulgaris show different specificity toward a-amylases. Zabrotes subfasciatus a-amylase is inhibited by a-AI2 but not by a-AI1. In contrast, porcine a-amylase is inhibited by a-AI1 but not by a-AI2. The objective of this work was to understand the molecular basis of the specificity of two inhibitors in P. vulgaris (a-AI1 and a-AI2) in relation to a-amylases. Mutants of a-AI2 were made and expressed in tobacco plants. The results showed that all the a-AI2 mutant inhibitors lost their activity against the insect a-amylases but none exhibited activity toward the mammalian a-amylase. The replacement of His33 of a-AI2 with the a-AI1-like sequence Ser-Tyr-Asn abolished inhibition of Z. subfasciatus a-amylase. From structural modeling, the conclusion is that the size and complexity of the amylase-inhibitor interface explain why mutation of the N-terminal loop and resultant abolition of Z. subfasciatus a-amylase inhibition are not accompanied by gain of inhibitory activity against porcine a-amylase.
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Da Lage, Jean-Luc. "The Amylases of Insects." International Journal of Insect Science 10 (January 2018): 117954331880478. http://dx.doi.org/10.1177/1179543318804783.
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Alpha-amylases are major digestive enzymes that act in the first step of maltopolysaccharide digestion. In insects, these enzymes have long been studied for applied as well as purely scientific purposes. In many species, amylases are produced by multiple gene copies. Rare species are devoid of Amy gene. They are predominantly secreted in the midgut but salivary expression is also frequent, with extraoral activity. Enzymological parameters are quite variable among insects, with visible trends according to phylogeny: Coleopteran amylases have acidic optimum activity, whereas dipteran amylases have neutral preference and lepidopteran ones have clear alkaline preference. The enzyme structure shows interesting variations shaped by evolutionary convergences, such as the recurrent loss of a loop involved in substrate handling. Many works have focused on the action of plant amylase inhibitors on pest insect amylases, in the frame of crop protection by transgenesis. It appears that sensitivity or resistance to inhibitors is finely tuned and very specific and that amylases and their inhibitors have coevolved. The multicopy feature of insect amylases appears to allow tissue-specific or stage-specific regulation, but also to broaden enzymological abilities, such as pH range, and to overcome plant inhibitory defenses.
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Rebholz, Gerold Felix, Karin Sebald, Sebastian Dirndorfer, Corinna Dawid, Thomas Hofmann, and Katharina Anne Scherf. "Impact of exogenous maltogenic α-amylase and maltotetraogenic amylase on sugar release in wheat bread." European Food Research and Technology 247, no. 6 (March 26, 2021): 1425–36. http://dx.doi.org/10.1007/s00217-021-03721-1.
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AbstractThe use of exogenous maltogenic α-amylases or maltotetraogenic amylases of bacterial origin is common in wheat bread production, mainly as antistaling agents to retard crumb firming. To study the impact of maltogenic α-amylase and maltotetraogenic amylase on straight dough wheat bread, we performed a discovery-driven proteomics approach with commercial enzyme preparations and identified the maltotetraogenic amylase P22963 from Pelomonas saccharophila and the maltogenic α-amylase P19531 from Geobacillus stearothermophilus, respectively, as being responsible for the amylolytic activity. Quantitation of mono-, di- and oligosaccharides and residual amylase activity in bread crumb during storage for up to 96 h clarified the different effects of residual amylase activity on the sugar composition. Compared to the control, the application of maltogenic α-amylase led to an increased content of maltose and especially higher maltooligosaccharides during storage. Residual amylase activity was detectable in the breads containing maltogenic α-amylase, whereas maltotetraogenic amylase only had a very low residual activity. Despite the residual amylase activities and changes in sugar composition detected in bread crumb, our results do not allow a definite evaluation of a potential technological function in the final product. Rather, our study contributes to a fundamental understanding of the relation between the specific amylases applied, their residual activity and the resulting changes in the saccharide composition of wheat bread during storage.
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Chrispeels, Maarten J., M. Fatima Grossi de Sa, and T. J. V. Higgins. "Genetic engineering with α-amylase inhibitors makes seeds resistant to bruchids." Seed Science Research 8, no. 2 (June 1998): 257–64. http://dx.doi.org/10.1017/s0960258500004153.
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AbstractSeeds of the common bean, Phaseolus vulgaris, contain two inhibitors of mammalian and insect α-amylases (αAls) that show specificity towards the amylases of different insect species. Expression in pea (Pisum sativum) and azuki bean (Vigna angularis) of a chimeric gene consisting of the cDNA of bean αAl-1 and a seed-specific promoter makes the seeds of these legumes resistant to three species of Old World bruchids whose amylases are inhibited by αAl-1. This was the first successful genetic engineering of insect resistance in seeds. To understand the basis of the specificity between amylases and inhibitors we cloned a second bean inhibitor (αAl-2) with different specificity, and we cloned the cDNA of the New World bruchid, Zabrotes subfasciatus. The amylase of this bruchid is inhibited by αAl-2, but not by αAl-1. Knowledge of the amino acid sequences and of the three-dimensional structure of the pancreatic α-amylase–αAl-1 complex allows us to predict the peptide domains and amino acids of the proteins that are important for protein–protein recognition and inhibition of enzyme activity.
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Gómez-Villegas, Patricia, Javier Vigara, Luis Romero, Cecilia Gotor, Sara Raposo, Brígida Gonçalves, and Rosa Léon. "Biochemical Characterization of the Amylase Activity from the New Haloarchaeal Strain Haloarcula sp. HS Isolated in the Odiel Marshlands." Biology 10, no. 4 (April 16, 2021): 337. http://dx.doi.org/10.3390/biology10040337.
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Alpha-amylases are a large family of α,1-4-endo-glycosyl hydrolases distributed in all kingdoms of life. The need for poly-extremotolerant amylases encouraged their search in extreme environments, where archaea become ideal candidates to provide new enzymes that are able to work in the harsh conditions demanded in many industrial applications. In this study, a collection of haloarchaea isolated from Odiel saltern ponds in the southwest of Spain was screened for their amylase activity. The strain that exhibited the highest activity was selected and identified as Haloarcula sp. HS. We demonstrated the existence in both, cellular and extracellular extracts of the new strain, of functional α-amylase activities, which showed to be moderately thermotolerant (optimum around 60 °C), extremely halotolerant (optimum over 25% NaCl), and calcium-dependent. The tryptic digestion followed by HPLC-MS/MS analysis of the partially purified cellular and extracellular extracts allowed to identify the sequence of three alpha-amylases, which despite sharing a low sequence identity, exhibited high three-dimensional structure homology, conserving the typical domains and most of the key consensus residues of α-amylases. Moreover, we proved the potential of the extracellular α-amylase from Haloarcula sp. HS to treat bakery wastes under high salinity conditions.
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MD Makut, FU Alfa, IK Ekeleme, JE Owuna, and NJ Emelogu. "Production of amylases by some aspergillus and fusarium species isolated from waste corncobs in Keffi, Nigeria." GSC Biological and Pharmaceutical Sciences 16, no. 2 (August 30, 2021): 122–29. http://dx.doi.org/10.30574/gscbps.2021.16.2.0216.
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Amylases are important industrial enzymes that have wide applications ranging from conversion of starch to sugar syrups, to the production of cyclodextrins for the pharmaceutical industry. This investigation aimed at production of amylases using Aspergillus and Fusarium species isolated from waste-corncobs in Keffi Nigeria. Standard microbiological methods were employed for isolation and identification of the fungal isolates. The yields of amylases produced by fungi isolates were determined using Spectrometry. The isolation rate of Aspergillus and Fusarium species was high in location A, C and D with 60% and location B with 40%. The percentage occurrence of the isolates demonstrated that Aspergillus carneus was 40%, Aspergillus aculeatus was 60% and Aspergillus flavus was 20% while Fusarium moniliforme was 80% and Fusarium redolens was 40%. The result demonstrated that three species of the fungal isolates Aspergillus aculeatus, Aspergillus carneus and Fusarium moniliforme were found to produce amylases. Aspergillus aculeatus isolated from locations C3, D1 and D2 produced 0.018mg/ml, 0.018mg/ml and 0.016mg/ml amylases respectively. Similarly, Aspergillus carneus isolated from locations A1 and B2 produced 0.021mg/ml and 0.012mg/ml amylases. Fusarium moniliforme isolated from locations A3, C1 and C4 produced 0.010mg/ml, 0.016mg/ml and 0.015mg/ml amylases. Result of effect of (temperature, pH and fermentation time) for production of amylases. Whereas highest amount for amylases produced by Aspergillus aculeatus and F monliforme were produced at 28 OC. pH 5.0 was found to the best optima pH for production of amylases from the fungi studied A. carneus (2.99 mg/ml amylases). The fermentation time showed highest production of amylase by A. carneus and A. aculeatus after 72 hours while F. moniliforme produced at 96hours. The fungi species isolated from soil in keffi can be used for production of amylases.
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Solovyeva, Nurguyana E., and Nikalay N. Novikov. "The brewing properties formation of barley grain depending on nutrition regime and phytoregulators application when growth on sod-podzolic soil." Butlerov Communications 59, no. 8 (August 31, 2019): 124–31. http://dx.doi.org/10.37952/roi-jbc-01/19-59-8-124.
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In the field experiments with brewing barley, carried out on sod-podzolic medium-loamy soil, it has been found out, that the raising doses of nitrogen application increased grain productivity of barley plants (by 18-33%), grains protein content, α-amylases, сatalases and peroxidases activity, but decreased grain unit and β-amylases activity. In water deficit weather conditions (Hydrothermal coefficient of moisture on the G.T Selyaninov = 1-1.3) the raising doses of phosphorus and potassium (Р120, К120) increased the grain productivity of barley plants (by10-28%), the mass of 1000 grains, their germination ability and α-amylases activity, but decreased β-amylases, сatalases, peroxidases activity and grains protein content making it not more then normative level (12%). In 7-days germinated grains of barley harvested in the variants with raising doses of nitrogen it has been revealed increasing of α-amylases, proteases, catalases, peroxidases activity, but decreasing of β-amylases activity. In the variants with higher doses of phosphorus and potassium barley grains were formed, which observed on the 7th day of sprouting increased α-amylases and peroxidases activity and reduced activity of β-amylases. It has been revealed, that phytoregulators novosil and epin application enhanced grain productivity of barley plants (by 6-14%) and α-amylases activity in grains, but decreased β-amylases activity. In water deficit weather conditions novosil phytoregulator reduced grains protein content to normative level. In the variants with epin phytoregulators application barley grains were formed in which germination increased amylase and peroxidase activity, improving their ability to malting.
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Loncar, Davor, Vladimir Filipovic, and Jelena Filipovic. "Optimisation of amylase and xylanase addition in dependance of white flour amylase activity." Chemical Industry 70, no. 6 (2016): 673–83. http://dx.doi.org/10.2298/hemind150814004l.
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In this study the effect of different quantities of added amylase to white wheat flours characterized with different activities of naturally existing amylases is tested. Response surface methodology is chosen to test the effects of main applied technological parameters on bread quality responses. Independent variables are chosen to be: quantity of added amylase and bulk fermentation time, while analysed responses are: specific volume, grain structure, bulk fermentation. Bread quality responses are statistically significant, while predicted and observed responses correspond very well, which allows good prediction of bread quality parameters based on applied technological parameters and flour characteristics. Score analysis shows that optimum quantity of amylase addition regarding bread quality depends on the activity of naturally existing amylases. Optimal quantity of added xylanase in bread samples made from both flour types is 0.004%. Xylanase improved properties of white wheat bread and higher effect is experienced with flour that has more active naturally existing amylases. Addition of amylase has statistically significantly increased a* values of crust. Addition of xylanase has statistically significantly decreased values of b* in comparison to the respective bread sample with only added amylase.
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Zhang, Xiaodong, Caixia Li, Xuantong Chen, Chonlong Chio, Sarita Shrestha, and Wensheng Qin. "Bacillus velezensis Identification and Recombinant Expression, Purification, and Characterization of Its Alpha-Amylase." Fermentation 7, no. 4 (October 11, 2021): 227. http://dx.doi.org/10.3390/fermentation7040227.
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Amylases account for about 30% of the global market of industrial enzymes, and the current amylases cannot fully meet industrial needs. This study aimed to identify a high α-amylase producing bacterium WangLB, to clone its α-amylase coding gene, and to characterize the α-amylase. Results showed that WangLB belonged to Bacillus velezensis whose α-amylase gene was 1980 bp coding 659 amino acids designated as BvAmylase. BvAmylase was a hydrophilic stable protein with a signal peptide and a theoretical pI of 5.49. The relative molecular weight of BvAmylase was 72.35 kDa, and was verified by SDS-PAGE. Its modeled structure displayed that it was a monomer composed of three domains. Its optimum temperature and pH were 70 °C and pH 6.0, respectively. It also showed high activity in a wide range of temperatures (40–75 °C) and a relatively narrow pH (5.0–7.0). It was a Ca2+-independent enzyme, whose α-amylase activity was increased by Co2+, Tween 20, and Triton X-100, and severely decreased by SDS. The Km and the Vmax of BvAmylase were 3.43 ± 0.53 and 434.19 ± 28.57 U/mg. In conclusion, the α-amylase producing bacterium WangLB was identified, and one of its α-amylases was characterized, which will be a candidate enzyme for industrial applications.
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Kachan, Alexandr, and Anatoliy Evtushenkov. "Thermostable mutant variants of Bacillus sp. 406 α-amylase generated by site-directed mutagenesis." Open Life Sciences 8, no. 4 (April 1, 2013): 346–56. http://dx.doi.org/10.2478/s11535-013-0142-0.
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AbstractSeveral mutations are known to increase the thermostability of α-amylase of B. licheniformis and other α-amylases. Site-directed mutagenesis was used to introduce similar mutations into the sequence of the α-amylase gene from mesophilic Bacillus sp. 406. The influence of the mutations on thermostability of the enzyme was studied. It was shown that the Gly211Val and Asn192Phe substitutions increased the half-inactivation temperature (Tm) of the enzyme from 51.94±0.45 to 55.51±0.59 and 58.84±0.68°C respectively, in comparison to the wild-type enzyme. The deletion of Arg178-Gly179 (dRG) resulted in an increase of Tm of the α-amylase to 71.7±1.73°C. The stabilising effect of mutations was additive. When combined they increase the Tm of the wild-type amylase by more than 26°C. Thermostability rates of the triple mutant are close to the values which are typical for industrial heat-stable α-amylases, and its ability to degrade starch at 75°C was considerably increased. The present research confirmed that the Gly211Val, Asn192Phe and dRG mutations could play a significant role in thermostabilization of both mesophilic and thermophilic α-amylases.
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Lim, Si J., Siti Nur Hazwani-Oslan, and Siti N. Oslan. "Purification and characterisation of thermostable α-amylases from microbial sources." BioResources 15, no. 1 (November 26, 2019): 2005–29. http://dx.doi.org/10.15376/biores.15.1.2005-2029.
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α-Amylases (E.C 3.2.1.1) hydrolyse starch into smaller moieties such as maltose and glucose by breaking α-1,4-glycosidic linkages. The application of α-amylases in various industries has made the large-scale productions of these enzymes crucial. Thermostable α-amylase that catalyses starch degradation at the temperatures higher than 50 °C is favourable in harsh industrial applications. Due to ease in genetic manipulation and bulk production, this enzyme is most preferably produced by microorganisms. Bacillus sp. and Escherichia coli are commonly used microbial expression hosts for α-amylases (30 to 205 kDa in molecular weight). These amylases can be purified using ultrafiltration, salt precipitation, dialysis, and column chromatography. Recently, affinity column chromatography has shown the most promising result where the recovery rate was 38 to 60% and purification up to 13.2-fold. Microbial thermostable α-amylases have the optimum temperature and pH ranging from 50 °C to 100 °C and 5.0 to 10.5, respectively. These enzymes have high specificity towards potato starch, wheat starch, amylose, and amylopectin. EDTA (1 mM) gave the highest inhibitory effect (79%), but Ca2+ (5 mM) was the most effective co-factor with 155%. This review provides insight regarding thermostable α-amylases obtained from microbial sources for industrial applications.
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Jeang, Chii-Ling, Li-Shien Chen, Ming-Yu Chen, and Rong-Jen Shiau. "Cloning of a Gene Encoding Raw-Starch-Digesting Amylase from a Cytophaga sp. and Its Expression in Escherichia coli." Applied and Environmental Microbiology 68, no. 7 (July 2002): 3651–54. http://dx.doi.org/10.1128/aem.68.7.3651-3654.2002.
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ABSTRACT A raw-starch-digesting amylase (RSDA) gene from a Cytophaga sp. was cloned and sequenced. The predicted protein product contained 519 amino acids and had high amino acid identity to α-amylases from three Bacillus species. Only one of the Bacillus α-amylases has raw-starch-digesting capability, however. The RSDA, expressed in Escherichia coli, had properties similar to those of the enzyme purified from the Cytophaga sp.
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Rodr�guez-Sanoja, R., B. Ruiz, J. P. Guyot, and S. Sanchez. "Starch-Binding Domain Affects Catalysis in Two Lactobacillus α-Amylases." Applied and Environmental Microbiology 71, no. 1 (January 2005): 297–302. http://dx.doi.org/10.1128/aem.71.1.297-302.2005.
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ABSTRACT A new starch-binding domain (SBD) was recently described in α-amylases from three lactobacilli (Lactobacillus amylovorus, Lactobacillus plantarum, and Lactobacillus manihotivorans). Usually, the SBD is formed by 100 amino acids, but the SBD sequences of the mentioned lactobacillus α-amylases consist of almost 500 amino acids that are organized in tandem repeats. The three lactobacillus amylase genes share more than 98% sequence identity. In spite of this identity, the SBD structures seem to be quite different. To investigate whether the observed differences in the SBDs have an effect on the hydrolytic capability of the enzymes, a kinetic study of L. amylovorus and L. plantarum amylases was developed, with both enzymes acting on several starch sources in granular and gelatinized forms. Results showed that the amylolytic capacities of these enzymes are quite different; the L. amylovorus α-amylase is, on average, 10 times more efficient than the L. plantarum enzyme in hydrolyzing all the tested polymeric starches, with only a minor difference in the adsorption capacities.
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Rokhati, Nur, Prita Widjajanti, Bambang Pramudono, and Heru Susanto. "Performance Comparison of α- and β-Amylases on Chitosan Hydrolysis." ISRN Chemical Engineering 2013 (December 12, 2013): 1–5. http://dx.doi.org/10.1155/2013/186159.
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The low solubility in common solvent and high viscosity resulting from its high molecular weight (MW) with fiber-like structure prevents a more widespread use of chitosan. This paper presents a performance comparison of nonspecific, commercially available enzymes, α- and β-amylases, for the hydrolysis of chitosan to lower its MW. The results showed that both enzymes demonstrate the ability to be used as catalysts in chitosan hydrolysis with β-amylase having better performance than α-amylase. The chitosan hydrolysis was influenced by not only the enzyme and the chitosan characteristics but also the hydrolysis condition. The optimum pH solution was 4 for α-amylase and 5 for β-amylase. The hydrolysis temperature was found to be optimal at 90 and 50°C for α- and β-amylases, respectively.
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Gligorijevic, Nikola, Nikola Stevanovic, Nikola Loncar, Rada Baosic, Zoran Vujcic, and Natasa Bozic. "A thin layer chromatographic comparison of raw and soluble starch hydrolysis patterns of some α-amylases from Bacillus sp. isolated in Serbia." Journal of the Serbian Chemical Society 79, no. 4 (2014): 411–20. http://dx.doi.org/10.2298/jsc130909155g.
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Several natural isolates of Bacillus strains namely 5B, 12B, 16B, 18 and 24B were grown on two different temperatures in submerged fermentation for the raw-starch-digesting a-amylases production. All strains except Bacillus sp. 18 produced more ?-amylase on 37?C. The hydrolysis of raw corn starch followed same pattern. Efficient hydrolysis was obtained with ?-amylases from Bacillus sp. 5B, 12B, 16B and 24B grown on 37?C and Bacillus sp. 18 grown on 50?C. Zymography after isoelectric focusing shown that ?-amylases were produced in multiple forms, from 2 to 6, depending on the strain when they were growing at 37 ?C, while growing at 50?C induced only 1 or 2 isoforms. TLC analysis of hydrolysis products of raw corn and soluble starch by ?-amylases revealed production of various mixtures of oligosaccharides. In most cases G3 was the most dominant product from soluble starch while G2, G3 and G5 were the main products of raw starch hydrolysis. This indicates that obtained a-amylases can be used for starch liquefying or short-chain-oligosaccharide forming, depending on what type of starch (raw or soluble) was used for the hydrolysis.
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Souza, Mariana Tainná Silva, Barbhara Mota Marinho, Thiago Machado Pasin, David Lee Nelson, and Vivian Machado Benassi. "PROSPECTION OF FILAMENTOUS FUNGI AND THE PRODUCTION OF AMYLASE BY ASPERGILLUS sp. M1.7.2." Journal of Engineering and Exact Sciences 6, no. 3 (September 4, 2020): 0365–76. http://dx.doi.org/10.18540/jcecvl6iss3pp0365-0376.
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Amylases are used in numerous industrial applications for converting starch into products of greater value. This work aimed to prospect filamentous fungi, analyze the morphological and physiological characteristics of the isolates; as well as to select an amylase producing fungus and to optimize the parameters for the cultivation of the microorganism and biochemically characterize the amylase. Among 21 filamentous fungi isolated in Janaúba, state of Minas Gerais, Brazil, the best amylase producer was selected for standardization of culture parameters and subsequent enzymatic characterization. Maximum activity was obtained in CP medium after six days of cultivation at 30 °C. Amylases produced by this fungus are stable to variations in pH and temperature, exhibited optimum activities at 65 oC and pH 6.0, and were significantly activated in the presence of 5 and 10 mm KH2PO4.
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Rodríguez-Viera, Leandro, Daniel Alpízar-Pedraza, Juan Miguel Mancera, and Erick Perera. "Toward a More Comprehensive View of α-Amylase across Decapods Crustaceans." Biology 10, no. 10 (September 22, 2021): 947. http://dx.doi.org/10.3390/biology10100947.
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Decapod crustaceans are a very diverse group and have evolved to suit a wide variety of diets. Alpha-amylases enzymes, responsible for starch and glycogen digestion, have been more thoroughly studied in herbivore and omnivore than in carnivorous species. We used information on the α-amylase of a carnivorous lobster as a connecting thread to provide a more comprehensive view of α-amylases across decapods crustaceans. Omnivorous crustaceans such as shrimps, crabs, and crayfish present relatively high amylase activity with respect to carnivorous crustaceans. Yet, contradictory results have been obtained and relatively high activity in some carnivores has been suggested to be a remnant trait from ancestor species. Here, we provided information sustaining that high enzyme sequence and overall architecture conservation do not allow high changes in activity, and that differences among species may be more related to number of genes and isoforms, as well as transcriptional and secretion regulation. However, recent evolutionary analyses revealed that positive selection might have also occurred among distant lineages with feeding habits as a selection force. Some biochemical features of decapod α-amylases can be related with habitat or gut conditions, while less clear patterns are observed for other enzyme properties. Likewise, while molt cycle variations in α-amylase activity are rather similar among species, clear relationships between activity and diet shifts through development cannot be always observed. Regarding the adaptation of α-amylase to diet, juveniles seem to exhibit more flexibility than larvae, and it has been described variation in α-amylase activity or number of isoforms due to the source of carbohydrate and its level in diets, especially in omnivore species. In the carnivorous lobster, however, no influence of the type of carbohydrate could be observed. Moreover, lobsters were not able to fine-regulate α-amylase gene expression in spite of large changes in carbohydrate content of diet, while retaining some capacity to adapt α-amylase activity to very low carbohydrate content in the diets. In this review, we raised arguments for the need of more studies on the α-amylases of less studied decapods groups, including carnivorous species which rely more on dietary protein and lipids, to broaden our view of α-amylase in decapods crustaceans.
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Moreira, Fabiana Guillen, Francieli Arrias de Lima, Sophia Renata Fazzano Pedrinho, Veridiana Lenartovicz, Cristina Giatti Marques de Souza, and Rosane Marina Peralta. "Production of amylases by Aspergillus tamarii." Revista de Microbiologia 30, no. 2 (April 1999): 157–62. http://dx.doi.org/10.1590/s0001-37141999000200014.
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A strain of Aspergillus tamarii, a filamentous fungus isolated from soil, was able to produce both <FONT FACE="Symbol">a</FONT>-amylase and glucoamylase activities in mineral media supplemented with 1% (w/v) starch or maltose as the carbon source. Static cultivation led to significantly higher yields than those obtained using shaking culture. The production of amylases was tolerant to a wide range of initial culture pH values (from 4 to 10) and temperature (from 25 to 42oC). Two amylases, one <FONT FACE="Symbol">a</FONT>-amylase and one glucoamylase, were separated by ion exchange chromatography. Both partially purified enzymes had optimal activities at pH values between 4.5 and 6.0 and were stable under acid conditions (pH 4.0-7.0). The enzymes exhibited optimal activities at temperatures between 50o and 60o C and were stable for more than ten hours at 55oC.
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Shinde, Ashok A., Faiyaz K. Shaikh, and Manvendra S. Kachole. "Exploration of Amylases Producing Competency of Helicoverpa armigera Gut Bacterial Strain, Bacillus subtilis RTSBA6 6.00." Cihan University-Erbil Scientific Journal 3, no. 1 (June 30, 2019): 75–79. http://dx.doi.org/10.24086/cuesj.v3n1y2019.pp75-79.
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The Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a polyphagous insect pest of agriculturally important crops. The alkaline gut of this insect pest possesses diverse bacterial communities which may assist in digestive physiology. As part our investigations of understanding the role of gut bacterial communities in insect gut, here amylase producing competency of earlier identified H. armigera gut bacterial strain, i.e., Bacillus subtilis RTSBA6 6.00 is reported. Initial screening for amylase activity was assessed by starch agar plate. Upon 7% sodium dodecyl sulfate polyacrylamide gel electrophoresis amylase zymography, bacterial culture supernatant produced seven amylase bands on the gel. The observed molecular weights of amylases were 191.2 KDa, 158.0 KDa, 131.7 KDa, 54.0 KDa, 31.3 KDa, 67.2 KDa, and 44.6 KDa, respectively. Considerable amylase activity was observed in neutral to alkaline pH with optimum at pH 6.8. The optimal activity temperature of amylases was found to be 50°C, and the activity decreased dramatically at temperatures above 75°C.
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Nair, Girish R., and Suresh S. S. Raja. "Characterization and phylogenetic analysis of alkaline α-amylase producing Brevibacillus laterosporus from mountain climatic zone of India." Journal of Drug Delivery and Therapeutics 9, no. 3 (May 15, 2019): 125–29. http://dx.doi.org/10.22270/jddt.v9i3.2618.
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α-amylases (EC3.2.1.1) are glycoside hydrolases that breakdown complex starch and maltodextrins into glucose and maltose by acting upon 1,4-glycosidiclinkages. Several amylases have been isolated and purified from members of Bacillus community, which find extensive application in starch processing, textile and pharmaceutical industry. Keeping this in mind we isolated α-amylase producing gram positive bacterium from soils collected from mountain climatic zone of India and identified it as Brevibacillus laterosporus. We further studied the effect of temperature and pH on the amylase activity of this strain and found a very stable activity at alkaline pH of 10 and temperature of 45 ºC. To our knowledge this a first report on characterization and evolutionary analysis of alkaline α-amylase producing Brevibacillus laterosporus isolated from unexplored sites of mountain climatic zone of India.
Keywords: Climatic zone, Brevibacillus, Amylase, 16S rRNA gene sequencing, Phylogenetic analysis
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Gupta, Nisha, Jai Shankar Paul, and S. K. Jadhav. "In Silico Approaches to Reveal Structural Insights, Stability and Catalysis of Bacillus-Derived α-Amylases Prior to Advance Lab Experiments." Journal of Computational Biophysics and Chemistry 20, no. 08 (November 26, 2021): 853–67. http://dx.doi.org/10.1142/s2737416521500538.
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[Formula: see text]-amylase is the most widely used Glycoside Hydrolase (GH) in industries for decades. It randomly cleaves the [Formula: see text]-D-(1, 4) glucosidic bonds of [Formula: see text]-polysaccharides (starch and glycogen) to release glucose and short-chain oligosaccharides. Substantial advances have taken place in research related to [Formula: see text]-amylases. However, bioinformatics study needs a little more exploration before conducting wet-lab experiments. We aimed to perform a comparative structure-function relationship study of 10 different Bacillus-derived [Formula: see text]-amylases using several computational biology tools. After aligning all the [Formula: see text]-amylases, 3D structures were made using the SWISS-MODEL. The accuracy and stability of the predicted models were validated via different web servers like Verify-3D, ERRAT, RMSD and ProSA. MolProbity and PROCHECK were used for mapping the residues in the most favored region of the Ramachandran plot. The Ramachandran plot reveals that [Formula: see text] of the amino acid residues of the selected [Formula: see text]-amylase genes lie within the favored region. Our findings suggest that all the [Formula: see text]-amylases were stable as per the validation results we got. The study has revealed clear and concise structural related aspects. This paper will encourage the researchers to include and prioritize in silico work of [Formula: see text]-amylase genes to obtain more accurate outcomes. As the output obtained in this study via in silico tools reveals the structural peculiarity and more about the catalytic domain impression, it highly recommends incorporating such studies for better results. This approach will save efforts, costs and time for researchers.
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Madhu, Amit, and J. N. Chakraborty. "Recovery and reuse of immobilized α-amylase during desizing of cotton fabric." Research Journal of Textile and Apparel 22, no. 3 (September 10, 2018): 271–90. http://dx.doi.org/10.1108/rjta-12-2017-0052.
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Purpose Enzymatic desizing using α-amylase is the conventional and eco-friendly method of removing starch based size. Conventionally, enzymes are drained after completion of process; being catalysts, they retain their activity after reaction and need to be reused. Immobilization allows the recovery of enzymes to use them as realistic biocatalyst. This study aims to recover and reuse of α-amylase for desizing of cotton via immobilization. Design/methodology/approach This paper investigates the application of α-amylase immobilized on Chitosan and Eudragit S-100 for cotton fabric desizing. A commercial α-amylase was immobilized on reversibly soluble-insoluble polymers to work out with inherent problems of heterogeneous reaction media. The immobilization process was optimized for maximum conjugate activity, and immobilized amylases were applied for grey cotton fabric desizing. Findings The desizing performance of immobilized amylases was evaluated in terms of starch removal and was compared to free enzyme. The immobilized amylases showed adequate desizing efficiency up to four cycles of use and were recovered easily at the end of each cycle. The amylase immobilized on Eudragit is more efficient for a particular concentration than chitosan. Practical implications Immobilization associates with insolubility and increased size of enzymes which lead to poor interactions and limited diffusion especially in textiles where enzymes have to act on macromolecular substrates (heterogeneous media). The selection of support materials plays a significant role in this constraint. Originality/value The commercial α-amylase was covalently immobilized on smart polymers for cotton fabric desizing. The target was to achieve immobilized amylase with maximum conjugate activity and limited constraints. The reversibly soluble-insoluble polymers support provide easy recovery with efficient desizing results in heterogeneous reaction media.
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Gorus, F., L. Deruyter, B. De Waele, and C. Sevens. "Agarose electrophoresis and inhibitor tests for isoamylase determination can give complementary clinical information." Clinical Chemistry 32, no. 2 (February 1, 1986): 398–400. http://dx.doi.org/10.1093/clinchem/32.2.398.
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Abstract We report the presence of an extremely high proportion of "aged" amylase in the serum and cyst fluid of a patient with a pancreatic pseudocyst. A salivary amylase inhibitor test helped us to differentiate these "aged" pancreatic amylases from salivary fractions having a similar electrophoretic mobility.
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Quek, Wei Ping, Wenwen Yu, Glen P. Fox, and Robert G. Gilbert. "Molecular structure-property relations controlling mashing performance of amylases as a function of barley grain size." Amylase 3, no. 1 (January 1, 2019): 1–18. http://dx.doi.org/10.1515/amylase-2019-0001.
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Abstract In brewing, amylases are key enzymes in hydrolyzing barley starch to sugars, which are utilized in fermentation to produce ethanol. Starch fermentation depends on sugars produced by amylases and starch molecular structure, both of which vary with barley grain size. Grain size is a major industrial specification for selecting barley for brewing. An in-depth study is given of how enzyme activity and starch structure vary with grain size, the impact of these factors on fermentable sugar production, and the underlying mechanisms. Micro-malting and mashing experiments were based on commercial methodologies. Starch molecular structural parameters were obtained using size-exclusion chromatography, and fitted using biosynthesis-based models. Correlation analysis using the resulting parameters showed larger grain sizes contained fewer long amylopectin chains, higher amylase activities and soluble protein level. Medium grain sizes released most sugars during mashing, because of higher starch utilization from the action of amylases, and shorter amylose chains. As starch is the substrate for amylase-driven fermentable sugars production, measuring its structure should be a prime indication for mashing performance, and should be used as an industry specification when selecting barley grains for brewing.
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Janíčková, Zuzana, and Štefan Janeček. "In Silico Analysis of Fungal and Chloride-Dependent α-Amylases within the Family GH13 with Identification of Possible Secondary Surface-Binding Sites." Molecules 26, no. 18 (September 21, 2021): 5704. http://dx.doi.org/10.3390/molecules26185704.
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This study brings a detailed bioinformatics analysis of fungal and chloride-dependent α-amylases from the family GH13. Overall, 268 α-amylase sequences were retrieved from subfamilies GH13_1 (39 sequences), GH13_5 (35 sequences), GH13_15 (28 sequences), GH13_24 (23 sequences), GH13_32 (140 sequences) and GH13_42 (3 sequences). Eight conserved sequence regions (CSRs) characteristic for the family GH13 were identified in all sequences and respective sequence logos were analysed in an effort to identify unique sequence features of each subfamily. The main emphasis was given on the subfamily GH13_32 since it contains both fungal α-amylases and their bacterial chloride-activated counterparts. In addition to in silico analysis focused on eventual ability to bind the chloride anion, the property typical mainly for animal α-amylases from subfamilies GH13_15 and GH13_24, attention has been paid also to the potential presence of the so-called secondary surface-binding sites (SBSs) identified in complexed crystal structures of some particular α-amylases from the studied subfamilies. As template enzymes with already experimentally determined SBSs, the α-amylases from Aspergillus niger (GH13_1), Bacillus halmapalus, Bacillus paralicheniformis and Halothermothrix orenii (all from GH13_5) and Homo sapiens (saliva; GH13_24) were used. Evolutionary relationships between GH13 fungal and chloride-dependent α-amylases were demonstrated by two evolutionary trees—one based on the alignment of the segment of sequences spanning almost the entire catalytic TIM-barrel domain and the other one based on the alignment of eight extracted CSRs. Although both trees demonstrated similar results in terms of a closer evolutionary relatedness of subfamilies GH13_1 with GH13_42 including in a wider sense also the subfamily GH13_5 as well as for subfamilies GH13_32, GH13_15 and GH13_24, some subtle differences in clustering of particular α-amylases may nevertheless be observed.
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Chessa, Jean-Pierre, Georges Feller, and Charles Gerday. "Purification and characterization of the heat-labile α-amylase secreted by the psychrophilic bacterium TAC 240B." Canadian Journal of Microbiology 45, no. 6 (July 15, 1999): 452–57. http://dx.doi.org/10.1139/w99-021.
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A total of 59 bacteria samples from Antarctic sea water were collected and screened for their ability to produce α-amylase. The highest activity was recorded from an isolate identified as an Alteromonas species. The purified α-amylase shows a molecular mass of about 50 000 Da and a pI of 5.2. The enzyme is stable from pH 7.5 to 9 and has a maximal activity at pH 7.5. Compared with other α-amylases from mesophiles and thermophiles, the "cold enzyme" displays a higher activity at low temperature and a lower stability at high temperature. The psychrophilic α-amylase requires both Cl-and Ca2+for its amylolytic activity. Br-is also quite effecient as an allosteric effector. The comparison of the amino acid composition with those of other α-amylases from various organisms shows that the cold α-amylase has the lowest content in Arg and Pro residues. This could be involved in the principle used by the psychrophilic enzyme to adapt its molecular structure to the low temperature of the environment. Key words: α-amylase, psychrophilic microorganisms, Antarctic.
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Offen, Wendy A., Anders Viksoe-Nielsen, Torben V. Borchert, Keith S. Wilson, and Gideon J. Davies. "Three-dimensional structure of a variant `Termamyl-like'Geobacillus stearothermophilusα-amylase at 1.9 Å resolution." Acta Crystallographica Section F Structural Biology Communications 71, no. 1 (January 1, 2015): 66–70. http://dx.doi.org/10.1107/s2053230x14026508.
Full textAbstract:
The enzyme-catalysed degradation of starch is central to many industrial processes, including sugar manufacture and first-generation biofuels. Classical biotechnological platforms involve steam explosion of starch followed by the action of endo-acting glycoside hydrolases termed α-amylases and then exo-acting α-glucosidases (glucoamylases) to yield glucose, which is subsequently processed. A key enzymatic player in this pipeline is the `Termamyl' class of bacterial α-amylases and designed/evolved variants thereof. Here, the three-dimensional structure of one such Termamyl α-amylase variant based upon the parentGeobacillus stearothermophilusα-amylase is presented. The structure has been solved at 1.9 Å resolution, revealing the classical three-domain fold stabilized by Ca2+and a Ca2+–Na+–Ca2+triad. As expected, the structure is similar to theG. stearothermophilusα-amylase but with main-chain deviations of up to 3 Å in some regions, reflecting both the mutations and differing crystal-packing environments.
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Khushk, Imrana. "Environmental Friendly Production of Amylase from Aspergillus niger EFRL-FC-024 Using Corn Waste as Carbon Source." Pakistan Journal of Analytical & Environmental Chemistry 22, no. 1 (June 23, 2021): 165–71. http://dx.doi.org/10.21743/pjaec/2021.06.17.
Full textAbstract:
Amylase is an indispensable and industrially important enzyme that hydrolyzes carbohydrates particularly starch into simple sugars. Amylase enzymes have been isolated from various sources such as microbes, animals and plants. However, microorganisms are highly preferred as compared to plants and animal sources. Amylases of fungal origin are highly stable compared to amylases produced by bacterial species. The aim of this study was to investigate the production of extracellular amylase enzyme from Aspergillus niger EFRL-FC-024 using sugarcane bagasse and corn waste as an energy source under submerge fermentation conditions. Primarily, the fungal strain was grown for 6 days using sugarcane bagasse and corn waste, respectively. Mainly, the growth of a microorganism was also evaluated using different pH, temperature and incubation periods. The results revealed maximum amylase production of 1.64 U/mL when A. niger was cultured for 96 h using corn waste. Moreover, addition of different nitrogen sources showed the highest amylase production when peptone was supplemented as a nitrogen source. Finally, the effect of pH indicated maximal concentration of amylase enzyme at pH 6.0. The present study will highly be beneficial to explore the role of fungal strain A. niger in amylase production at Industrial levels.
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Celestino, Jessyca dos Reis, Ana Caroline Duarte, Cláudia Maria de Melo Silva, Hellen Holanda Sena, Maria do Perpétuo Socorro Borges Carriço Ferreira, Neila Hiraishi Mallmann, Natacha Pinheiro Costa Lima, et al. "Aspergillus 6V4, a Strain Isolated from Manipueira, Produces High Amylases Levels by Using Wheat Bran as a Substrate." Enzyme Research 2014 (March 2, 2014): 1–4. http://dx.doi.org/10.1155/2014/725651.
Full textAbstract:
The aim of this study was screening fungi strains, isolated from manipueira (a liquid subproduct obtained from the flour production of Manihot esculenta), for amylases production and investigating production of these enzymes by the strain Aspergillus 6V4. The fungi isolated from manipueira belonged to Ascomycota phylum. The strain Aspergillus 6V4 was the best amylase producer in the screening assay of starch hydrolysis in petri dishes (ASHPD) and in the assay in submerged fermentation (ASbF). The strain Aspergillus 6V4 produced high amylase levels (335 UI/L) using wheat bran infusion as the exclusive substrate and the supplementation of this substrate with peptone decreased the production of this enzyme. The moisture content of 70% was the best condition for the production of Aspergillus 6V4 amylases (385 IU/g) in solid state fermentation (SSF).
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Almulaiky, Yaaser Q., Faisal M. Aqlan, Musab Aldhahri, Mohammed Baeshen, Tariq Jamal Khan, Khalid A. Khan, Mohamed Afifi, et al. "α-Amylase immobilization on amidoximated acrylic microfibres activated by cyanuric chloride." Royal Society Open Science 5, no. 11 (November 2018): 172164. http://dx.doi.org/10.1098/rsos.172164.
Full textAbstract:
Enzyme immobilization is one of the most important techniques for industrial applications. It makes the immobilized enzyme more stable and advantageous than the free form in different aspects. α-Amylase was immobilized on 4% cyanuric chloride-activated amidoximated acrylic fabric at pH 7.0 with (79%) maximum efficiency. A field emission scanning electron microscope and Fourier transform infrared were used to confirm the immobilization process. Even after being recycled 10 times, the immobilized enzyme lost just 28% of its initial activity. Owing to immobilization, the pH of the soluble α-amylase was shifted from 6.0 to 6.5. The immobilized α-amylases showed thermal stability at 60°C, and became more resistant to heavy metal ions. The k m values of the immobilized and soluble α-amylases were 9.6 and 3.8 mg starch ml −1 , respectively. In conclusion, this method shows that the immobilized α-amylase proved to be more efficient than its soluble form, and hence could be used during saccharification of starch.
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Islam, Md Rayhan, Omit Kumer Mondol, Md Saimoon Rahman, Md Morsaline Billah, Mohammad Shahedur Rahman, and Umme Salma Zohora. "Screening of ?-amylase producing bacteria from tannery wastes of Hazaribag, Bangladesh." Jahangirnagar University Journal of Biological Sciences 5, no. 2 (June 11, 2017): 1–10. http://dx.doi.org/10.3329/jujbs.v5i2.32511.
Full textAbstract:
Alpha amylases (?-amylases) are one of the most imperative enzymes for producing simple sugar units from complex sugar molecules. Attempts were made to isolate amylolytic bacterial strains from soil samples of tannery wastes collected from Hazaribagh, Dhaka and subsequent partial characterization was performed. Bacterial isolates were primarily screened for ?- amylase activity on starch agar medium. Based on microscopic and biochemical properties of isolates, ?-amylase activity of bacterial isolates were determined to find out two best producers of the enzyme. Subsequent molecular identification of these two ?-amylase producing bacterial isolates using 16s rRNA sequence analysis showed that isolates were Bacillus amyloliquefaciens and B. subtilis respectively. In submerged fermentation the B. amyloliquefaciens showed the highest activity (2.13 U/ml) while B. subtilis showed the second highest activity (1.89 U/ml). Characterization of the enzyme produced by B. amyloliquefaciens revealed that the maximum activity demonstrated at incubation time 25 min, pH 7.0 and temperature 500C. This newly isolated B. amyloliquefaciens could be exploited for the industrial production of ?-amylase with commercial implications.Jahangirnagar University J. Biol. Sci. 5(2): 1-10, 2016 (December)
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Hirano, Yu, Kana Tsukamoto, Shingo Ariki, Yuki Naka, Mitsuhiro Ueda, and Taro Tamada. "X-ray crystallographic structural studies of α-amylase I from Eisenia fetida." Acta Crystallographica Section D Structural Biology 76, no. 9 (August 25, 2020): 834–44. http://dx.doi.org/10.1107/s2059798320010165.
Full textAbstract:
The earthworm Eisenia fetida possesses several cold-active enzymes, including α-amylase, β-glucanase and β-mannanase. E. fetida possesses two isoforms of α-amylase (Ef-Amy I and II) to digest raw starch. Ef-Amy I retains its catalytic activity at temperatures below 10°C. To identify the molecular properties of Ef-Amy I, X-ray crystal structures were determined of the wild type and of the inactive E249Q mutant. Ef-Amy I has structural similarities to mammalian α-amylases, including the porcine pancreatic and human pancreatic α-amylases. Structural comparisons of the overall structures as well as of the Ca2+-binding sites of Ef-Amy I and the mammalian α-amylases indicate that Ef-Amy I has increased structural flexibility and more solvent-exposed acidic residues. These structural features of Ef-Amy I may contribute to its observed catalytic activity at low temperatures, as many cold-adapted enzymes have similar structural properties. The structure of the substrate complex of the inactive mutant of Ef-Amy I shows that a maltohexaose molecule is bound in the active site and a maltotetraose molecule is bound in the cleft between the N- and C-terminal domains. The recognition of substrate molecules by Ef-Amy I exhibits some differences from that observed in structures of human pancreatic α-amylase. This result provides insights into the structural modulation of the recognition of substrates and inhibitors.
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Kumar Maharana, Abhas, and Shiv Mohan Singh. "Cold Active Amylases Producing Psychrotolerants Isolated from Nella Lake, Antarctica." Biosciences, Biotechnology Research Asia 15, no. 1 (March 25, 2018): 05–16. http://dx.doi.org/10.13005/bbra/2603.
Full textAbstract:
Cold active amylase was investigated by bacteria and yeast isolates from the sediment core samples of Nella Lake,Larsemann Hills region, East Antarctica. Between potential yeast and bacteria isolates screened for amylases, best isolates were identified asRhodotorula sp. Y-37 and ArthrobacteralpinusN16 by molecular technique.Amylase production capabilities of both the isolate subjected for optimization processes by using submerged fermentation technique with soluble starch as substrate.The results indicate that a supplement of 1% w/v glucose, 1% w/v yeast extract and 0.1% w/v KCl at pH 7.0with 5% v/v inoculum enhances the amylase production by 5.72-fold using Rhodotorula sp. Y-37. In other hands, the activators are 1% w/v of galactose and peptone, 0.1% w/v KCl and 2.5% v/v inoculum at pH 7.0 enhances the amylase production by 3.74-fold using ArthrobacteralpinusN16. Cold-active amylasecan be used in detergent, textile, food and beverage industries. Bio-degradation of starchy materials by cold active amylases can contribute in cleaning of environment at cold regions without harming the climate.