1
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Effect of Barium Addition on Hydrolytic Enzymatic Activities in Food Waste Degradation under Anaerobic Conditions. Processes (Basel) 2020. [DOI: 10.3390/pr8111371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Enzymatic hydrolysis of complex components of residual materials, such as food waste, is a rate-limiting step that conditionates the production rate of biofuels. Research into the anaerobic degradation of cellulose and starch, which are abundant components in organic waste, could contribute to optimize biofuels production processes. In this work, a lab-scale anaerobic semi-continuous hydrolytic reactor was operated for 171 days using food waste as feedstock; the effect of Ba2+ dosage over the activity of five hydrolytic enzymes was also evaluated. No significant effects were observed on the global performance of the hydrolytic process during the steady-state of the operation of the reactor, nevertheless, it was detected that Ba2+ promoted β-amylases activity by 76%, inhibited endoglucanases and α-amylases activity by 39 and 20%, respectively, and had no effect on β-glucosidases and glucoamylases activity. The mechanisms that rule the observed enzymatic activity changes remain unknown; however, the discussion in this paper provides hypothetical explanations for further research.
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2
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Deploey JJ, Nasta M, Adams PR. Quantitative Determinations of the Temperature and pH Stability of Extracellular Amylase Obtained fromMucor Pusillus. Mycologia 2018. [DOI: 10.1080/00275514.1982.12021595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- J. J. Deploey
- Department of Biology, The Pennsylvania State University, York Campus, York, Pennsylvania 17403
| | - M. Nasta
- Department of Chemistry, The Pennsylvania State University, York Campus, York, Pennsylvania 17403
| | - P. R. Adams
- Department of Chemistry, The Pennsylvania State University, York Campus, York, Pennsylvania 17403
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3
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Shabbiri K, Adnan A, Noor B, Jamil S. Optimized production, purification and characterization of alpha amylase by Brevibacterium linens DSM 20158, using bio-statistical approach. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0286-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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4
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Forsberg CW, Beveridge TJ, Hellstrom A. Cellulase and Xylanase Release from Bacteroides succinogenes and Its Importance in the Rumen Environment. Appl Environ Microbiol 2010; 42:886-96. [PMID: 16345891 PMCID: PMC244123 DOI: 10.1128/aem.42.5.886-896.1981] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During growth of Bacteroides succinogenes in a liquid medium with cellulose as the source of carbohydrate, greater than 80% of the carboxymethylcellulase (endo-beta-1,4-glucanase), xylanase, and aryl-beta-xylosidase and 50% of the aryl-beta-glucosidase released from cells into the culture fluid. Less than 25% of the cellobiase activity was detected in the culture fluid. Approximately 50% of each of the released enzymes measured was associated with sedimentable subcellular membrane vesicles. The vesicles appeared to be released from the outer membrane of intact cells by bleb formation, primarily in pockets between the cells and the cellulose, although a few unattached cells with blebs were seen. Many vesicles were seen adhering to cellulose, and they were also seen free in the culture fluid. These data suggest that B. succinogenes releases hydrolytic enzymes in nonsedimentable and particulate forms during growth by a mechanism which has until now received little attention. Cellulose incubated in a porous nylon bag in the rumen was colonized by bacteria resembling B. succinogenes, and subcellular vesicles were seen penetrating channels and fractures in the cellulose. On this basis, it is suggested that B. succinogenes cells in the rumen contribute to an extracellular population of subcellular vesicles that possess cellulolytic and hemicellulolytic activities which probably enhance polymer digestion and provide a source of sugars for microbes lacking polymer-degrading activity, thereby contributing to a stable heterogeneous microbial population.
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Affiliation(s)
- C W Forsberg
- Department of Microbiology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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5
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Onishi H, Sonoda K. Purification and Some Properties of an Extracellular Amylase from a Moderate Halophile, Micrococcus halobius. Appl Environ Microbiol 2010; 38:616-20. [PMID: 16345444 PMCID: PMC243549 DOI: 10.1128/aem.38.4.616-620.1979] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A moderate halophile, Micrococcus halobius ATCC 21727, produced an extracellular dextrinogenic amylase when cultivated in media containing 1 to 3 M NaCl. The amylase was purified from the culture filtrate to an electrophoretically homogenous state by glycogen-complex formation, diethylaminoethyl-cellulose chromatography, and Bio-Gel P-200 gel filtration. The enzyme had maximal activity at pH 6 to 7 in 0.25 M NaCl or 0.75 M KCl at 50 to 55 degrees C. The activity was lost by dialysis against distilled water. Molecular weight was estimated to be 89,000 by sodium dodecyl sulfate-gel electrophoresis. The action pattern on amylose, soluble starch, and glycogen showed that the products were maltose, maltotriose, and maltotetraose, with lesser amount of glucose.
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Affiliation(s)
- H Onishi
- Department of Agricultural Chemistry, Kagoshima University, Korimoto, Kagoshima-shi, Japan 890
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6
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Fárez-Vidal ME, Fernandez-Vivas A, Arias JM. Production of α-amylase by Myxococcus coralloides D. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2672.1992.tb01702.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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7
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Sirotek K, Marounek M, Suchorská O. Activity and cellular localization of amylases of rabbit cecal bacteria. Folia Microbiol (Praha) 2006; 51:309-12. [PMID: 17007433 DOI: 10.1007/bf02931821] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Five 11-week-old rabbits, fed a commercial granulated feed, were slaughtered and cecal starch-degrading bacteria enumerated; total concentration of cultivable bacteria utilizing starch averaged 5.5 x 10(10) CFU/g. The activity and cellular localization of amylases was determined in 9 bacteria identified as Actinomyces israeli (strains AA2 and AD4), Bacteroides spp. (strain AA3), Dichelobacter nodosus (strain AA4), Mitsuokella multiacidus (strain AA6), Eubacterium spp. (strains AA7 and AB2), Clostridium spp. (strains AD1 and AA5). Four strains (AA3, AA4, AA5, AD4) produced extracellular amylases with an activity of 26-35 micromol of reducing sugars per h per mg of protein; in five strains (AA2, AA6, AA7, AB2, AD1) amylases were membrane-bound with an activity of 14-18 micromol of reducing sugars per h per mg of protein. All strains exhibited a low intracellular amylolytic activity. The pH optimum of amylases was 6.8-7.0. In strains producing extracellular amylases a substantial loss of viscosity was observed during incubations of cultivation supernatant with starch, similar to viscosity reduction in starch solutions treated with alpha-amylase; this indicates an endo-type (random cleavage) of extracellular amylase reaction in the bacteria under study. No strain possessed glucoamylase activity.
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Affiliation(s)
- K Sirotek
- Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Prague, Czechia
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8
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Anderson KL. Purification and Analysis of a Membrane-associated Starch-degrading Enzyme from Ruminobacter amylophilus. Anaerobe 2002. [DOI: 10.1006/anae.2002.0435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Ogata K, Sekizaki T, Aminov RI, Tajima K, Nakamura M, Nagamine T, Matsui H, Benno Y. A small cryptic plasmid from Ruminobacter amylophilus NIAH-3 possesses functional mobilization properties. FEMS Microbiol Lett 1999; 181:41-8. [PMID: 10564787 DOI: 10.1111/j.1574-6968.1999.tb08824.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The complete nucleotide sequence of a small cryptic plasmid designated pRAO1, from the Gram-negative ruminal bacterium Ruminobacter amylophilus NIAH-3, was determined. The plasmid is a circular DNA molecule, 2140 bp in size, with a GC content of 40%. Computer-assisted analysis identified three open reading frames (ORFs), one of which, ORF3 (347 amino acids), displayed a high degree of amino acid identity with the Mob proteins involved in conjugative mobilization and interplasmid recombination of plasmids from Gram-positive bacteria. We proved the mobilization properties of pRAO1 in the Escherichia coli system using the coresident IncW broad-host-range conjugative plasmid R388. These data demonstrated, for the first time, the mobilization properties of small cryptic plasmids from Gram-negative inhabitants of the rumen.
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Affiliation(s)
- K Ogata
- STAFF Institute, Tsukuba, Ibaraki, Japan
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10
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Abstract
Ruminobacter amylophilus is an obligate anaerobe that uses only alpha-linked glucose molecules (i.e., maltose, maltodextrins, and starch) as a source of energy, making it an excellent model for the study of bacterial starch degradation. Constitutive amylase, amylopectinase, and pullulanase activities were found in intracellular and extracellular fractions of R. amylophilus. However, extracellular activities apparently resulted from cell lysis. Both soluble and membrane-bound polysaccharidase activities were detected. Most of the soluble polysaccharidase activity partitioned with the periplasmic cell fraction. No alpha-glucosidase or maltase activity was detected in either the cellular or extracellular fraction. In addition, intact cells of R. amylophilus bound U-14C-starch. This binding could be saturated and was constitutive and sensitive to proteinase K, indicating protein or protein complex mediation. Competition experiments showed that these starch-binding sites had equally high affinities for starch and maltodextrins larger than maltotriose. The sites had a reduced affinity for maltose and virtually no affinities for glucose and nonstarch polysaccharides. These findings suggest that R. amylophilus binds starch molecules to the cell surface as an initial step in transporting the molecule through the outer membrane and into the periplasmic space. Extracellular polysaccharides do not appear to be involved in starch degradation.
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Affiliation(s)
- K L Anderson
- Department of Biological Sciences, Mississippi State University, Mississippi 39762, USA
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11
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Rumbak E, Rawlings DE, Lindsey GG, Woods DR. Cloning, nucleotide sequence, and enzymatic characterization of an alpha-amylase from the ruminal bacterium Butyrivibrio fibrisolvens H17c. J Bacteriol 1991; 173:4203-11. [PMID: 2061294 PMCID: PMC208071 DOI: 10.1128/jb.173.13.4203-4211.1991] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A Butyrivibrio fibrisolvens amylase gene was cloned and expressed by using its own promoter on the recombinant plasmid pBAMY100 in Escherichia coli. The amylase gene consisted of an open reading frame of 2,931 bp encoding a protein of 976 amino acids with a calculated Mr of 106,964. In E. coli(pBAMY100), more than 86% of the active amylase was located in the periplasm, and TnphoA fusion experiments showed that the enzyme had a functional signal peptide. The B. fibrisolvens amylase is a calcium metalloenzyme, and three conserved putative calcium-binding residues were identified. The amylase showed high sequence homology with other alpha-amylases in the three highly conserved regions which constitute the active centers. These and other conserved regions were located in the N-terminal half, and no similarity with any other amylase was detected in the remainder of the protein. Deletion of approximately 40% of the C-terminal portion of the amylase did not result in loss of amylolytic activity. The B. fibrisolvens amylase was identified as an endo-alpha-amylase by hydrolysis of the Phadebas amylase substrate, hydrolysis of gamma-cyclodextrin to maltotriose, maltose, and glucose and the characteristic shape of the blue value and reducing sugar curves. Maltotriose was the major initial hydrolysis product from starch, although extended incubation resulted in its hydrolysis to maltose and glucose.
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Affiliation(s)
- E Rumbak
- Department of Microbiology, University of Cape Town, South Africa
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12
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Ueki A, Hirono T, Sato E, Mitani A, Ueki K. Ethanol and amylase production by a newly isolated Clostridium sp. World J Microbiol Biotechnol 1991; 7:385-93. [DOI: 10.1007/bf00329407] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/1990] [Accepted: 01/05/1991] [Indexed: 11/28/2022]
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13
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McAllister TA, Cheng KJ, Rode LM, Forsberg CW. Digestion of Barley, Maize, and Wheat by Selected Species of Ruminal Bacteria. Appl Environ Microbiol 1990; 56:3146-53. [PMID: 16348322 PMCID: PMC184913 DOI: 10.1128/aem.56.10.3146-3153.1990] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Differences in the digestion of barley, maize, and wheat by three major ruminal starch-digesting bacterial species,
Streptococcus bovis
26,
Ruminobacter amylophilus
50, and
Butyrivibrio fibrisolvens
A38, were characterized. The rate of starch digestion in all cereal species was greater for
S. bovis
26 than for
R. amylophilus
50 or
B. fibrisolvens
A38. Starch digestion by
S. bovis
26 was greater in wheat than in barley or maize, whereas starch digestion by
R. amylophilus
50 was greater in barley than in maize or wheat.
B. fibrisolvens
A38 digested the starch in barley and maize to a similar extent but was virtually unable to digest the starch in wheat. The higher ammonia concentration in cultures of
B. fibrisolvens
A38 when grown on wheat than when grown on barley or maize suggests that
B. fibrisolvens
A38 utilized wheat protein rather than starch. Scanning electron microscopy revealed that
B. fibrisolvens
A38 initially colonized cell wall material, while
S. bovis
26 randomly colonized the endosperm and
R. amylophilus
50 preferentially colonized starch granules. There was subsequent colonization but only superficial digestion of wheat starch granules by
B. fibrisolvens
A38. Variation in the association between starch and protein within the endosperm of cereal grains contributes to the differential effectiveness with which amylolytic species can utilize cereal starch.
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Affiliation(s)
- T A McAllister
- Research Station, Agriculture Canada, Lethbridge, Alberta T1J 4B1, and University of Guelph, Guelph, Ontario N1G 2W1, Canada
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14
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Abstract
Starch-degrading, amylolytic enzymes are widely distributed among microbes. Several activities are required to hydrolyze starch to its glucose units. These enzymes include alpha-amylase, beta-amylase, glucoamylase, alpha-glucosidase, pullulan-degrading enzymes, exoacting enzymes yielding alpha-type endproducts, and cyclodextrin glycosyltransferase. Properties of these enzymes vary and are somewhat linked to the environmental circumstances of the producing organisms. Features of the enzymes, their action patterns, physicochemical properties, occurrence, genetics, and results obtained from cloning of the genes are described. Among all the amylolytic enzymes, the genetics of alpha-amylase in Bacillus subtilis are best known. Alpha-Amylase production in B. subtilis is regulated by several genetic elements, many of which have synergistic effects. Genes encoding enzymes from all the amylolytic enzyme groups dealt with here have been cloned, and the sequences have been found to contain some highly conserved regions thought to be essential for their action and/or structure. Glucoamylase appears usually in several forms, which seem to be the results of a variety of mechanisms, including heterogeneous glycosylation, limited proteolysis, multiple modes of mRNA splicing, and the presence of several structural genes.
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Affiliation(s)
- M Vihinen
- Department of Biochemistry, University of Turku, Finland
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15
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Ali FS, Abdel-Moneim AA. Effect of chemicals on fungal alpha-amylase activity. ZENTRALBLATT FUR MIKROBIOLOGIE 1989; 144:623-8. [PMID: 2515680 DOI: 10.1016/s0232-4393(89)80126-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effect of 8 growth regulators at concentrations of 1,000, 5,000 and 10,000 ppm on the activity of fungal (Aspergillus flavus var. columnaris) alpha-amylase was studied. Indol acetic acid (IAA) and naphthalene acetic acid (NAA) inhibited alpha-amylase activity by 2% and 7% at 1,000 ppm. The other 6 growth regulators, indol butyric acid (IBA), gibberellic acid, cumarin, cycocel (CCC), atonik-G and kylar, did not inhibit but stimulated alpha-amylase activity (0 to 9%) at 1,000 ppm. All growth regulators studied inhibited alpha-amylase activity at 5,000 and 10,000 ppm concentration except kylar. The effect of organic acids and formaldehyde at 0.01, 0.005, and 0.001 M was studied. Acetic acid stimulated alpha-amylase at all concentrations, but formic acid, oxalic acid, lactic acid and citric acid inhibited alpha-amylase activity by 91, 100, 100 and 79%, respectively, at a concentration of 0.01 M, while by 31, 100, 15 and 20%, respectively, at 0.005 M. Formaldehyde induced 7, 3 and 2% inhibition at 0.01, 0.005 and 0.001 M, respectively. At 0.01 M either sorbitol or fructose inhibited alpha-amylase by 8%, Maltose 7%, sucrose 6%, phenol, glucose and galactose each by 5%, ethanol, glycerol, arabinose and sodium benzoate each by 4%, isopropanol and mannitol 1%, but methanol and ammonium citrate dibasic did not inhibit alpha-amylase. The results indicate that CuCl2, SnCl2, AgNO3 and Fe2(SO4)3 were the strongest inhibitors, followed by Cd(C2H3O2), HgCl2, Na2-EDTA, Na2HPO4, and CaCl2 in decreasing order. NaCl, NaBr and Mn SO4 did not inhibit alpha-amylase at concentrations from 10 mM to 0.01 mM.
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Affiliation(s)
- F S Ali
- Department of Agric. Microbiol., Fac. Agric., Minia University, Egypt
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16
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Shah HN, Williams RAD. Utilization of glucose and amino acids byBacteroides intermedius andBacteroides gingivalis. Curr Microbiol 1987. [DOI: 10.1007/bf01589374] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Stackebrandt E, Hippe H. Transfer of Bacteroides amylophilus to a new genus Ruminobacter gen. nov., nom. rev. as Ruminobacter amylophilus comb. nov. Syst Appl Microbiol 1986. [DOI: 10.1016/s0723-2020(86)80078-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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18
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Srivastava R. Studies on extracellular and intracellular purified amylases from a thermophilic Bacillus stearothermophilus. Enzyme Microb Technol 1984. [DOI: 10.1016/0141-0229(84)90018-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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19
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Kekos D, Macris BJ. Production and Characterization of Amylase from
Calvatia gigantea. Appl Environ Microbiol 1983; 45:935-41. [PMID: 16346256 PMCID: PMC242394 DOI: 10.1128/aem.45.3.935-941.1983] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
α-Amylase (EC 3.2.1.1) was excreted by
Calvatia gigantea
in liquid growth media containing different sources of starch. Among the factors affecting enzyme production in shake flasks were the type and the concentration of starch and the nitrogen source supplied. Optimum cultural conditions for maximum enzyme production were: soluble starch concentration, 5%; inoculum size, 3.75 × 10
5
conidia per ml; 5-day cultivation time at 28 to 30°C. The observed maximum yield of 81.3 U of saccharifying enzyme activity per ml of growth medium was the highest ever reported in the literature for submerged cultures. Partially purified enzyme functioned optimally at pH 4.5 to 5.5 and 53 to 58°C. The activation energy of enzymic hydrolysis of starch in the range of 20 to 40°C was 8,125 cal/mol (ca. 3.41 × 10
4
J). The apparent
K
m
value of the enzyme at 25°C was 7.68 × 10
−4
g/ml. Some of the properties of the enzyme under investigation were similar to those of α-amylases excreted from molds producing large amounts of the enzyme.
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Affiliation(s)
- D Kekos
- Department of Biology, Nuclear Research Center "Demokritos," Aghia Paraskevi, Attiki, Greece
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20
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Safwat M, Mahmoud S, Attia R, Abd-El-Nasser M, Ali F. Bacterial Alpha-Amylase Inhibitors. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/s0232-4393(83)80007-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Engvall A. alpha-Amylase activity in rumen fluid of cows producing milk of low and normal fat content. J Dairy Sci 1980; 63:2012-9. [PMID: 6162870 DOI: 10.3168/jds.s0022-0302(80)83177-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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22
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Medda S, Chandra AK. New strains of Bacillus licheniformis and Bacillus coagulans producing thermostable alpha-amylase active at alkaline pH. THE JOURNAL OF APPLIED BACTERIOLOGY 1980; 48:47-58. [PMID: 6154683 DOI: 10.1111/j.1365-2672.1980.tb05205.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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23
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Abstract
Bacillus brevis
NRRL B-4389 produced extracellular maltase (α-glucosidase; EC 3.2.1.20) only in the presence of short α-1,4-glucosidic polymers, such as maltose and maltotriose. An optimum medium was developed; it contained 2.5% maltose, 0.5% nonfat dry milk, 0.4% yeast extract, and 0.01% CaCl
2
. The enzyme was produced extracellularly during the logarithmic phase of growth; no cell-bound activity was detected at any time. Partial purification of the maltase was accomplished by using diethylaminoethyl cellulose batch adsorption, ammonium sulfate precipitation, and Sephadex G-200 gel filtration. Maltase, isomaltase (oligo-1,6-glucosidase), and glucosyltransferase activities were purified 20.0-, 19.1-, and 11.5-fold, respectively. Some properties of the partially purified maltase were determined: optimum pH, 6.5; optimum temperature, 48 to 50°C; pH stability range, 5.0 to 7.0; temperature stability range, 0 to 50°C; isoelectric point, pH 5.2; and molecular weight, 52,000. The relative rates of hydrolysis of maltose (G
2
), maltotriose (G
3
), G
4
, methyl-α-
d
-maltoside, G
40
, dextrin, and isomaltose were 100, 22, 12, 10, 10, 8, and 5%, respectively; the
K
m
on maltose was 5.8 mM;
d
-glucose,
p
-nitrophenyl-α-
d
-glucoside, and tris (hydroxymethyl) aminomethane were competitive inhibitors; transglucosylase activity of the enzyme on maltose resulted in the synthesis of isomaltose, isomaltotroise, and larger oligosaccharides.
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Affiliation(s)
- S J McWethy
- Department of Bacteriology, Iowa State University, Ames, Iowa 50011
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24
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Berg JO, Nord CE, Wadström T. Formation of glycosidases in batch and continuous culture of Bacteroides fragilis. Appl Environ Microbiol 1978; 35:269-73. [PMID: 25044 PMCID: PMC242824 DOI: 10.1128/aem.35.2.269-273.1978] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Nine strains of bacteroides fragilis were cultivated in stirred fermentors and tested for their ability to produce glycosidases. B. fragilis subsp. vulgatus B70 was used for optimizing the production of glycosidases. The highest bacterial yield was obtained in proteose peptone-yeast extract medium. The optimum pH for maximal bacterial yield was 7.0, and the optimum temperature for growth was 37 degrees C. The formation of glycosidases was optimal between pH 6.5 and 7.5, and the optimum temperature for synthesis of glycosidases was between 33 and 37 degrees C. Culture under controlled conditions in fermentors gave more reproducible production of glycosidases than static cultures in bottles. The strain was also grown in continuous culture at a dilution rate of 0.1 liter/h at pH 7.0 and 37 degrees C with a yield of 2.0 mg of dry weight per ml in the complex medium. The formation of glycosidases remained constant during the entire continuous process.
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25
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Kamekura M, Onishi H. Properties of the halophilic nuclease of a moderate halophile, Micrococcus varians subsp. halophilus. J Bacteriol 1978; 133:59-65. [PMID: 618848 PMCID: PMC221976 DOI: 10.1128/jb.133.1.59-65.1978] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The halophilic nuclease of Micrococcus varians ATCC 21971 hydrolyzed thymidine 5'-monophospho-p-nitrophenyl ester at a rate that increased with the NaCl concentration up to saturation. The nuclease attacked RNA and DNA exonucleolytically and processively, producing 5'-mononucleotides. The molecular weight of the enzyme as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 99,000, approximately the same as that previously determined for the native enzyme. Examination of amino acid composition showed that acidic amino acids were in high excess over basic amino acids.
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26
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Enzymes of Industrial Interest; Traditional Products. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/b978-0-12-040302-8.50010-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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