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Koritala BSC, Lee K. Natural Variation of the Circadian Clock in Neurospora. ADVANCES IN GENETICS 2017; 99:1-37. [PMID: 29050553 DOI: 10.1016/bs.adgen.2017.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Most living organisms on earth experience daily and expected changes from the rotation of the earth. For an organism, the ability to predict and prepare for incoming stresses or resources is a very important skill for survival. This cellular process of measuring daily time of the day is collectively called the circadian clock. Because of its fundamental role in survival in nature, there is a great interest in studying the natural variation of the circadian clock. However, characterizing the genetic and molecular mechanisms underlying natural variation of circadian clocks remains a challenging task. In this chapter, we will summarize the progress in studying natural variation of the circadian clock in the successful eukaryotic model Neurospora, which led to discovering many design principles of the molecular mechanisms of the eukaryotic circadian clock. Despite the success of the system in revealing the molecular mechanisms of the circadian clock, Neurospora has not been utilized to extensively study natural variation. We will review the challenges that hindered the natural variation studies in Neurospora, and how they were overcome. We will also review the advantages of Neurospora for natural variation studies. Since Neurospora is the model fungal species for circadian study, it represents over 5 million species of fungi on earth. These fungi play important roles in ecosystems on earth, and as such Neurospora could serve as an important model for understanding the ecological role of natural variation in fungal circadian clocks.
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Affiliation(s)
- Bala S C Koritala
- Department of Biology, Rutgers, The State University of New Jersey, Camden, NJ, United States; Center for Computational and Integrative Biology, Rutgers, The State University of New Jersey, Camden, NJ, United States
| | - Kwangwon Lee
- Department of Biology, Rutgers, The State University of New Jersey, Camden, NJ, United States; Center for Computational and Integrative Biology, Rutgers, The State University of New Jersey, Camden, NJ, United States.
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Adsul M, Sharma B, Singhania RR, Saini JK, Sharma A, Mathur A, Gupta R, Tuli DK. Blending of cellulolytic enzyme preparations from different fungal sources for improved cellulose hydrolysis by increasing synergism. RSC Adv 2014. [DOI: 10.1039/c4ra08129c] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A prepared enzyme cocktail from different fungal enzyme preparations increases the hydrolysis of avicel/wheat straw by increasing synergism between the same or different types of cellulases.
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Affiliation(s)
- Mukund Adsul
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Bhawna Sharma
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Reeta Rani Singhania
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Jitendra Kumar Saini
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Ankita Sharma
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Anshu Mathur
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Ravi Gupta
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
| | - Deepak Kumar Tuli
- DBT-IOC Centre for Advanced Bioenergy Research
- Indian Oil R and D Centre
- Faridabad-121007, India
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Amore A, Giacobbe S, Faraco V. Regulation of cellulase and hemicellulase gene expression in fungi. Curr Genomics 2013; 14:230-49. [PMID: 24294104 PMCID: PMC3731814 DOI: 10.2174/1389202911314040002] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 11/22/2022] Open
Abstract
Research on regulation of cellulases and hemicellulases gene expression may be very useful for increasing the production of these enzymes in their native producers. Mechanisms of gene regulation of cellulase and hemicellulase expression in filamentous fungi have been studied, mainly in Aspergillus and Trichoderma. The production of these extracellular enzymes is an energy-consuming process, so the enzymes are produced only under conditions in which the fungus needs to use plant polymers as an energy and carbon source. Moreover, production of many of these enzymes is coordinately regulated, and induced in the presence of the substrate polymers. In addition to induction by mono- and oligo-saccharides, genes encoding hydrolytic enzymes involved in plant cell wall deconstruction in filamentous fungi can be repressed during growth in the presence of easily metabolizable carbon sources, such as glucose. Carbon catabolite repression is an important mechanism to repress the production of plant cell wall degrading enzymes during growth on preferred carbon sources. This manuscript reviews the recent advancements in elucidation of molecular mechanisms responsible for regulation of expression of cellulase and hemicellulase genes in fungi.
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Affiliation(s)
- Antonella Amore
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
| | - Simona Giacobbe
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 4 80126 Naples, Italy
- School of Biotechnological Sciences, University of Naples “Federico II” Italy
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Abdel-Rahman MA, Tashiro Y, Zendo T, Shibata K, Sonomoto K. Isolation and characterisation of lactic acid bacterium for effective fermentation of cellobiose into optically pure homo l-(+)-lactic acid. Appl Microbiol Biotechnol 2010; 89:1039-49. [DOI: 10.1007/s00253-010-2986-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 10/25/2010] [Accepted: 10/25/2010] [Indexed: 11/25/2022]
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Scott WA, Metzenberg RL. Location of Aryl Sulfatase in Conidia and Young Mycelia of Neurospora crassa. J Bacteriol 2010; 104:1254-65. [PMID: 16559101 PMCID: PMC248285 DOI: 10.1128/jb.104.3.1254-1265.1970] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aryl sulfatase (arylsulfate sulfohydrolase, EC 3.1.6.1) was found to have multiple locations in Neurospora conidia. Some enzyme activity remained in the supernatant when a spore suspension was centrifuged or filtered. Part of the cell-bound activity could be detected by adding the assay ingredients to a suspension of intact spores (patent enzyme), and additional activity was only detectable when the spores were first treated to destroy their permeability barriers (cryptic enzyme). Such treatments include: disruption with an X-press, brief rinsing with chloroform or acetone, incubation at 60 C for 5 min, and incubation with phenethyl alcohol, nystatin, or ascosin. Part of the patent aryl sulfatase was inactivated by briefly acid treating the intact spores (no loss of conidial viability). This enzyme was considered to have a cell surface location. Some enzyme was acid-resistant in intact spores, but all of the enzyme was acid-sensitive in spores whose permeability barriers had been disrupted. The pH dependence, kinetic properties, and p-nitrophenyl sulfate uptake were investigated in acid-treated conidia. No aryl sulfatase was detected in ascospores. Young mycelia contained more aryl sulfatase than did conidia, but little, if any, was secreted into the growth medium. Cryptic activity was demonstrated in young mycelia by brief chloroform treatment or by rinsing the cells with 0.1 m acetate buffer. Enzyme activity in young mycelia was completely labile to acid treatment, as was cell viability.
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Affiliation(s)
- W A Scott
- Department of Physiological Chemistry, University of Wisconsin Medical School, Madison, Wisconsin 53706
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Bogo KR, Masui DC, Leone FA, Jorge JA, Furriel RPM. Structural and kinetic alterations of constitutive conidial alkaline phosphatase from the osmotically-sensitive mutant ofNeurospora crassa. Folia Microbiol (Praha) 2006; 51:431-7. [PMID: 17176763 DOI: 10.1007/bf02931587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The osmotically-sensitive os-1 mutant of Neurospora crassa overproduced conidial alkaline phosphatase. The enzyme was purified by Phenyl-Sepharose CL-4B chromatography and Sephadex G-200 gel filtration. PAGE analysis of the purified enzyme suggested the occurrence of aggregation and/or disaggregation phenomena. The enzyme is a glycoprotein containing 16% saccharide, with apparent molar mass of 137 kDa. Two protein bands (36 and 62 kDa) were observed in SDS-PAGE, suggesting that the native enzyme was a trimer. The pI was estimated to be 2.7, and optima of pH and temperature were 9.5 and 65 degrees C, respectively. The enzyme showed broad substrate specificity, hydrolyzing preferentially 4-nitrophenyl phosphate, O-phosphoamino-acids and 2-phosphoglycerate. The hydrolysis of 4-nitrophenyl phosphate was stimulated by Co(II) (26%), Ni(II) (23%) and Mg(II) ions (80%). The enzyme was stable for up to 6 months at 4 degrees C in 5 mmol/L Tris-HCl buffer and also upon storage at 25 degrees C for 10 d. The kinetic and structural properties of the conidial enzyme purified from the os-1 mutant were quite different from those of the wild type strain. The enzyme overproduction observed in the mutant may be related to cell wall alterations that affect the process of enzyme secretion.
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Affiliation(s)
- K R Bogo
- Departamento de Quimica, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto 14040-901, São Paulo, Brazil
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Adsul M, Ghule J, Singh R, Shaikh H, Bastawde K, Gokhale D, Varma A. Polysaccharides from bagasse: applications in cellulase and xylanase production. Carbohydr Polym 2004. [DOI: 10.1016/j.carbpol.2004.04.001] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
Inhibitory activity toward beta-glucosidase was detected in extracts of the lichen, Umbilicaria esculenta. The extract showed strong inhibition of disaccharide hydrolytic enzymes of mold and mammalian origin, but weak or no inhibition of polysaccharide hydrolytic enzymes except glucoamylase and laminarinase. The inhibitor in the extract was very stable, retaining more than 95% of its activity when treated with heat, acid, alkali, and some hydrolytic enzymes. Purified inhibitor was identified as 1-deoxynojirimycin (1,5-dideoxy-1,5-immino-D-glucitol) by NMR spectrometry, which was known to be produced by Streptomyces sp. and the plant Morus sp. Extracts from Parmelia austrosinensis, Parmelia praesorediosa, and an unidentified lichen species, showed glucosidase inhibitory activities similar to U. esculenta.
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Affiliation(s)
- K A Lee
- Korea Food Research Institute, Songnam, Korea
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BERGER LS, EBERHART BM. Extracellular beta-transglucosidase activity from conidia of Neurospora crassa. Biochem Biophys Res Commun 1998; 6:62-6. [PMID: 13867668 DOI: 10.1016/0006-291x(61)90186-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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12
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Abstract
Hill, E. P. (University of Michigan, Ann Arbor), and A. S. Sussman. Development of trehalase and invertase activity in Neurospora. J. Bacteriol. 88:1556-1566. 1964.-The levels of trehalase and invertase found during the development of Neurospora have been studied. Invertase activity is highest in the mycelium after growth has been completed, whereas the most trehalase activity is found in ungerminated conidia. Both enzymes show the least activity in the ascospore. Although the specific activity of trehalase varies no more than 3-fold during the spore stages, there is a 60-fold change in the mycelium. Similar but less pronounced variations in the specific activity of invertase in the mycelium occur. The lowest ratios of invertase to trehalase activity in the soluble fraction are found in conidia and ascospores, except in dormant ascospores where the ratio approaches that of older mycelium. Similar results are obtained for the enzymes in the wall fraction, except for dormant and newly activated ascospores. Moreover, the walls of young mycelium appear to have relatively more trehalase than is found at all other times. The activities of both enzymes vary about 20-fold in the wall fraction, but invertase activity fluctuates more widely than that of trehalase. Invertase activity always exceeds that of trehalase, and the cytoplasmic fraction contains more activity than that of the wall. These results are shown to contradict the hypothesis that trehalase and invertase activities are coordinately controlled. Finally, the role of trehalase in the activation of ascospores is considered in the light of these results.
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MAHADEVAN PR, EBERHART B. THE BETA-GLUCOSIDASE SYSTEM OF NEUROSPORA CRASSA. II. PURIFICATION AND CHARACTERIZATION OF ARYL BETA-GLUCOSIDASE. Arch Biochem Biophys 1996; 108:22-9. [PMID: 14233912 DOI: 10.1016/0003-9861(64)90350-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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EBERHART B, CROSS DF, CHASE LR. BETA-GLUCOSIDASE SYSTEM OF NEUROSPORA CRASSA. I. BETA-GLUCOSIDASE AND CELLULASE ACTIVITIES OF MUTANT AND WILD-TYPE STRAINS. J Bacteriol 1996; 87:761-70. [PMID: 14137612 PMCID: PMC277090 DOI: 10.1128/jb.87.4.761-770.1964] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eberhart, Bruce (University of North Carolina, Greensboro), David F. Cross, and Lewis R. Chase. beta-Glucosidase system of Neuspora crassa. I. beta-Glucosidase and cellulose activities of mutant and wild-type strains. J. Bacteriol. 87:761-770. 1964.-A mutant strain, gluc-1, of Neurospora crassa was isolated and characterized by its low level of beta-glucosidase activity. The mutant was selected by testing irradiated colonies for extracellular beta-glucosidase activity. Strains containing the gluc-1 gene were also visibly detected by their reduced ability to destroy esculin in their growth media. The mutant strain grew at wild-type rates with cellobiose or carboxymethylcellulose as carbon sources. This auxotrophic similarity with wild type is explained by the presence of at least two beta-glucosidases (and possibly two cellulases) in Neurospora that act complementarily. The thermolabile beta-glucosidase was destroyed after 1 min of incubation at 60 C. This enzyme was present in mycelia but absent in conidial extracts. A second beta-glucosidase that is comparatively stable at 60 C was present in both mycelia and conidia. A partial separation of these enzymes was achieved with ammonium fractionation of mycelial extracts of gluc-1 and wild-type strains. Thermolabile beta-glucosidase and cellulase activity appear not to be affected by the gluc-1 mutation, whereas the thermostable glucosidase is greatly reduced in gluc-1 strains.
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MAHADEVAN PR, EBERHART B. THE BETA-GLUCOSIDASE SYSTEM OF NEUROSPORA CRASSA. 3. FURTHER STUDIES ON AN ARYL BETA-GLUCOSIDASE MUTANT. Arch Biochem Biophys 1996; 108:30-5. [PMID: 14233913 DOI: 10.1016/0003-9861(64)90351-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Say JC, Furriel RP, Ciancaglini P, Jorge JA, Lourdes M, Polizeli TM, Pizauro JM, Terenzi HF, Leone FA. Conidial alkaline phosphatase from Neurospora crassa. PHYTOCHEMISTRY 1996; 41:71-75. [PMID: 8588877 DOI: 10.1016/0031-9422(95)00534-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An alkaline phosphatase was purified from conidia of a Neurospora crassa wild type strain. The M(r) of the purified native enzyme was estimated as ca 145,000 and 110,000 by gel filtration, in the presence and absence of magnesium ions, respectively. A single polypeptide band of M(r) 36,000 was detected by SDS-PAGE, suggesting that the native enzyme was a tetramer of apparently identical subunits. Conidial alkaline phosphatase was an acidic protein (pl = 4.0 +/- 0.1), with 40% carbohydrate content. Optimal pH was affected by substrate concentration and magnesium ions. Low concentrations of calcium ions (0.1 mM) had slight stimulatory effects, but in excess (5 mM) caused protein aggregates with decreased activity. The enzyme specificity against different substrates was compared with those reported for constitutive or Pi-repressible alkaline phosphatases produced by N. crassa. The results suggested that the conidial alkaline phosphatase represented a different class among other such enzymes synthesized by this organism.
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Affiliation(s)
- J C Say
- Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto-USP, Brazil
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17
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Gokhale DV, Patil SG, Bastawde KB. Optimization of cellulase production by Aspergillus niger NCIM 1207. Appl Biochem Biotechnol 1991; 30:99-109. [PMID: 1952926 DOI: 10.1007/bf02922026] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Aspergillus niger NCIM 1207 produces high levels of extracellular beta-glucosidase and xylanase activities in submerged fermentation. Among the nitrogen sources, ammonium sulfate, ammonium dihydrogen orthophosphate, and corn-steep liquor were the best for the production of cellulolytic enzymes by A. niger. The optimum pH and temperature for cellulase production were 3.0-5.5 and 28 degrees C, respectively. The cellulase complex of this strain was found to undergo catabolite repression in the presence of high concentrations of glucose. Glycerol at all concentrations caused catabolite repression of cellulase production. The addition of glucose (up to 1% concentration) enhanced the production of cellulolytic enzymes, but a higher concentration of glucose effected the pronounced repression of enzymes. Generally the growth on glucose- or glycerol-containing medium was accompanied by a sudden drop in the pH of the fermentation medium to 2.0.
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Affiliation(s)
- D V Gokhale
- NCIM, Division of Biochemical Sciences, Pune, India
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18
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Secretion of thermostable β-glucosidase by an intergeneric bacterial hybrid betweencellulomonas and bacillus subtilis. Appl Biochem Biotechnol 1990. [DOI: 10.1007/bf02921502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Peralta RM, Terenzi HF, Jorge JA. Beta-D-glycosidase activities of Humicola grisea: biochemical and kinetic characterization of a multifunctional enzyme. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1033:243-9. [PMID: 2107872 DOI: 10.1016/0304-4165(90)90127-i] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A beta-D-glycosidase activity was purified from mycelium of Humicola grisea var. thermoidea grown on avicel as the main carbon source. The purified enzyme was a glycoprotein and migrated as a single polypeptide band on polyacrylamide gel electrophoresis under native or denaturing conditions. The apparent molecular weight of the enzyme was estimated to be 55 kDa by gel filtration and SDS-PAGE. The enzyme was active against o-nitrophenyl beta-D-galactoside; p-nitrophenyl beta-D-glucoside, p-nitrophenyl beta-D-fucoside, lactose and cellobiose, PNP fucoside (synthetic substrate) and cellobiose (natural substrate) being the best utilized. A comparison of the properties of beta-D-galactosidase, beta-D-glucosidase and beta-D-fucosidase showed that three activities exhibited similar pH and temperature optima and the same thermostability. The hydrolysis rate of substrate mixtures suggests that the enzyme possesses a common catalytic site for all the substrates assayed.
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Affiliation(s)
- R M Peralta
- Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil
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Gokhale DV, Deobagkar DN. Differential Expression of Xylanases and Endoglucanases in the Hybrid Derived from Intergeneric Protoplast Fusion between a
Cellulomonas
sp. and
Bacillus subtilis. Appl Environ Microbiol 1989; 55:2675-80. [PMID: 16348034 PMCID: PMC203143 DOI: 10.1128/aem.55.10.2675-2680.1989] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A stable hybrid obtained by protoplast fusion between a
Cellulomonas
sp. and
Bacillus subtilis
exhibits an altered pattern of enzyme induction with different cellulosic substrates. Unlike in the
Cellulomonas
sp., xylanase was induced in the hybrid organism specifically by xylan, and endoglucanase was induced by carboxymethyl cellulose. The amount and specific activity of xylanase produced by the hybrid were more than those produced by the
Cellulomonas
sp. β-Glucosidase which is cell bound or intracellular in the
Cellulomonas
sp. was secreted by the hybrid organism, and relative amounts of extracellular β-glucosidase were high. Furthermore, this extracellular β-glucosidase activity was dependent on the nature of the cellulosic substrate. Endoglucanases synthesized in the hybrid differed in their electrophoretic mobilities as compared with the parental enzymes.
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Affiliation(s)
- D V Gokhale
- NCIM, Division of Biochemical Sciences, National Chemical Laboratory, Pune 411 008, and Department of Zoology, University of Poona, Pune 411 007, India
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Dhanni R, Singh A, Dhillon G, Kalra M. Isolation of hypercellulolytic mutants of Sclerotium rolfsii and saccharification of cellulosic residues. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0269-7483(88)90098-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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23
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Gokhale DV, Puntambekar US, Vyas AK, Patil SG, Deobagkar DN. Hyper production of ?-glucosidase by an Aspergillus sp. Biotechnol Lett 1984. [DOI: 10.1007/bf00133063] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Transfer of DNA coding for cellulases from Cellulomonas species to Bacillus subtilis by protoplast fusion. Biotechnol Lett 1984. [DOI: 10.1007/bf00133827] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Shatzman AR, Kosman DJ. Regulation of galactose oxidase synthesis and secretion in Dactylium dendroides: effects of pH and culture density. J Bacteriol 1977; 130:455-63. [PMID: 15985 PMCID: PMC235224 DOI: 10.1128/jb.130.1.455-463.1977] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The effects of pH and growth density on the amount of an extracellular enzyme, galactose oxidase, synthesized by the fungus Dactylium dendroides were studied. Growth at a pH below 6.7 caused a decrease in the ability of the organism to release galactose oxidase. The enzyme retained by these fungal cells was liberated whenever the pH was raised to 7.0. Cycloheximide addition failed to inhibit the appearance of this protein; [3H]leucine added prior to pH adjustment was not incorporated into the released protein, These observations indicate the released protein is not newly synthesized protein. The retained enzyme would be secreted slowly over a 2-day period if the pH was not increased. In addition to regulating protein retention, pH was also shown to be associated with vacuolization, cell volume, culture density, and inhibition of protein synthesis. Cultures maintained at low pH were characterized by a dense growth consisting of highly vacuolated, buoyant, fungal hyphae. Increasing the pH from 6 to 7 caused a decrease in vacuole size. Cells grown at neutral pH maintained a lower density of growth and, based on activity measurements, synthesized 33% more galactose oxidase. Furthermore, cultures grown at pH 6.0 and maintained at a lower cell density produced galactose oxidase at a level similar to that of cells grown at neutral pH. Thus, the elevated density of the cell culture was inhibitory to galactose oxidase synthesis. The observed effects on protein synthesis and release were rather specific for galactose oxidase, since other extracellular proteins appeared in the earliest stages of growth.
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North MJ. Increase of enzyme activities in Neurospora crassa during incubation at low temperatures. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 422:309-15. [PMID: 129162 DOI: 10.1016/0005-2744(76)90142-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effect of lowering the incubation temperature of sucrose-grown cultures of Neurospora crassa on the level of various enzyme activities was investigated. Of twelve inducible/derepressible activities studied, three, in addition to glycerol kinase, were found to increase during 48 h of incubation at 4-6 degrees C: trehalase (increase in specific activity of 3-10-fold), beta-glucosidase (6-12-fold) and beta-N-acetylglucosaminidase (4 to 6-fold). The maximum increases occurred at 6 degrees C and no increases took place in mycelia incubated at 0 degrees C. The kinetics of the changes in activity were markedly different from those observed previously with glycerol kinase. The increases were inhibited by cycloheximide. Trehalase, beta-glucosidase and beta-N-acetylglucosaminidase activities were not rapidly lost when cultures incubated at 6 degrees C were returned to 26 degrees C.
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Abstract
The induction of beta-glucosidases (EC 3.2.1.21) was studied in Neurospora crassa. Cellobiase was induced by cellobiose, but other inducers had little effect on this enzyme. Cellobiase activity was very low in all stages of the vegetative life cycle in the absence of di-beta-glucoside inducer. Aryl-beta-glucosidase was semiconstitutive at late stages of culture growth prior to conidiation. At early stages, aryl-beta-glucosidase was induced by cellobiose, laminaribiose, and gentiobiose, and weakly induced by galactose, amino sugars, and aryl-beta-glucosides. The induction properties of the beta-glucosidases are compared with those of the other disaccharidases of Neurospora. The induction of beta-glucosidases was inhibited by glucose, 2-deoxy-d-glucose, and sodium acetate. Sodium phosphate concentrations between 0.01 and 0.1 M stimulated induction of both enzymes, while concentrations above 0.1 M were inhibitory. The optimal condition for induction of both beta-glucosidases was pH 6.0. Cellobiase induction was relatively more inhibited than aryl-beta-glucosidase in the range of pH 6.0 to 8.0.
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Slayman CW, Slayman CL. Potassium transport in Neurospora. Evidence for a multisite carrier at high pH. J Gen Physiol 1970; 55:758-86. [PMID: 5424377 PMCID: PMC2203021 DOI: 10.1085/jgp.55.6.758] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
At low extracellular pH (4-6), net uptake of potassium by Neurospora is a simple exponential process which obeys Michaelis kinetics as a function of [K](o). At high pH, however, potassium uptake becomes considerably more complex, and can be resolved into two distinct exponential components. The fast component (time constant = 1.2 min) is matched quantitatively by a rapid loss of sodium; it is attributed to ion exchange within the cell wall, since it is comparatively insensitive to low temperature and metabolic inhibitors. By contrast, the slower component (time constant = 10.9 min) is inhibited markedly at 0 degrees C and by CN and deoxycorticosterone, and is thought to represent carrier-mediated transport of potassium across the cell membrane. This transport process exhibits sigmoid kinetics as a function of [K](o); the data can be fitted satisfactorily by two different two-site models (one involving a carrier site and a modifier site, the other an allosteric model). Either of these models could also accommodate the simple Michaelis kinetics at low pH.
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Abstract
The beta-glucosidases (EC 3.2.1.21) of Neurospora crassa were studied with respect to their location in conidia and young mycelia. Aryl-beta-glucosidase of conidia was nearly equally divided between extracellular and bound activity. Bound aryl-beta-glucosidase was almost all available to substrate. An induction procedure was used to maximize both beta-glucosidases in 4 to 6-hr cells. Aryl-beta-glucosidase was entirely bound but still mostly (90%) detectable, whereas cellobiase was mostly internal and cryptic. A freeze-thaw cycle or treatment with phenethyl alcohol or deoxycholic acid made the cellobiase detectable without releasing it from the cell. A 10 to 20% increase in cell-bound aryl-beta-glucosidase could be obtained by this treatment. Dilute HCl (0.1 n) destroyed the patent aryl-beta-glucosidase but not the cryptic aryl-beta-glucosidase or the cryptic cellobiase activity in intact cells. This suggested that most aryl-beta-glucosidase activity was exterior to the cell membrane but still within the mural space. The thermal stability of patent aryl-beta-glucosidase and released cellobiase was found to be higher than in corresponding cell-free extracts. Measurements of K(m) suggested a slightly lower affinity for substrate p-nitrophenyl-beta-d-glucopyranoside by the enzymes in intact cells compared to enzymes in extracts.
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Reiss J. [Cytochemical detection of hydrolases in fungus cells. I. Glycosidases]. HISTOCHEMIE. HISTOCHEMISTRY. HISTOCHIMIE 1969; 18:12-23. [PMID: 5810983 DOI: 10.1007/bf00309897] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Bucht B, Eriksson KE. Extracellular enzyme system utilized by the rot fungus Stereum sanguinolentum for the breakdown of cellulose. I. Studies on the enzyme production. Arch Biochem Biophys 1968; 124:135-41. [PMID: 5661592 DOI: 10.1016/0003-9861(68)90312-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Myers MG, Eberhart B. Regulation of cellulase and cellobiase in Neurospora crassa. Biochem Biophys Res Commun 1966; 24:782-5. [PMID: 5970513 DOI: 10.1016/0006-291x(66)90394-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Mahadevan PR, Eberhart BM. A dominant regulatory gene for aryl-beta-glucosidase inNeurospora crassa. ACTA ACUST UNITED AC 1962. [DOI: 10.1002/jcp.1030600311] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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