An evaluation of fungal enzymes for the solubilization of wheat bran constituents

1970 ◽  
Vol 16 (3) ◽  
pp. 139-146 ◽  
Author(s):  
T. S. Neudoerffer ◽  
R. E. Smith

Cellulolytic fungi were evaluated for their ability to use wheat bran and produce extracellular enzymes capable of solubilizing carbohydrate and protein fractions from wheat bran. Trichurus cylindricus grew better than all other organisms tested and excreted an extracellular enzyme system which was distinguished by high C1 and Cx cellulase and proteolytic activity. Evidence was also obtained for the existence of a partially extracellular lignolytic enzyme system. The extracellular enzyme system possessed high activity towards wheat bran and the dilute enzyme was able to bring about a 28% weight loss from the insoluble fraction of the wheat bran substrate in 24 h. The extracellular enzyme system from Trichoderma viride and Myrothecium verrucaria were also studied but they were found to be inferior to those of Trichurus cylindricus for the solubilization of wheat bran. However, the crude enzyme preparation from Trichurus cylindricus had a lower activity towards purified cellulose than the enzyme from Trichoderma viride.

2006 ◽  
Vol 72 (4) ◽  
pp. 2483-2490 ◽  
Author(s):  
Patthra Pason ◽  
Khin Lay Kyu ◽  
Khanok Ratanakhanokchai

ABSTRACT A facultatively anaerobic bacterium, Paenibacillus curdlanolyticus B-6, isolated from an anaerobic digester produces an extracellular xylanolytic-cellulolytic enzyme system containing xylanase, β-xylosidase, arabinofuranosidase, acetyl esterase, mannanase, carboxymethyl cellulase (CMCase), avicelase, cellobiohydrolase, β-glucosidase, amylase, and chitinase when grown on xylan under aerobic conditions. During growth on xylan, the bacterial cells were found to adhere to xylan from the early exponential growth phase to the late stationary growth phase. Scanning electron microscopic analysis revealed the adhesion of cells to xylan. The crude enzyme preparation was found to be capable of binding to insoluble xylan and Avicel. The xylanolytic-cellulolytic enzyme system efficiently hydrolyzed insoluble xylan, Avicel, and corn hulls to soluble sugars that were exclusively xylose and glucose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of a crude enzyme preparation exhibited at least 17 proteins, and zymograms revealed multiple xylanases and cellulases containing 12 xylanases and 9 CMCases. The cellulose-binding proteins, which are mainly in a multienzyme complex, were isolated from the crude enzyme preparation by affinity purification on cellulose. This showed nine proteins by SDS-PAGE and eight xylanases and six CMCases on zymograms. Sephacryl S-300 gel filtration showed that the cellulose-binding proteins consisted of two multienzyme complexes with molecular masses of 1,450 and 400 kDa. The results indicated that the xylanolytic-cellulolytic enzyme system of this bacterium exists as multienzyme complexes.


1969 ◽  
Vol 49 (2) ◽  
pp. 205-214 ◽  
Author(s):  
T. S. Neudoerffer ◽  
R. E. Smith

The enzymic degradation of wheat bran using cellulolytic and proteolytic enzymes from a number of sources was investigated. Two enzyme combinations were found to be effective for the chemical alteration of wheat bran. Crude enzyme preparation from the fungus T. viride in combination with a commercial proteinase brought about a 32% reducing sugar accumulation, a 36% loss of holocellulose, a 40% loss of α-cellulose and a, 54% solubilization of protein. Crude enzyme preparation from the fungus M. verrucaria in combination with a commercial proteinase gave rise to a 27% reducing sugar accumulation, a 39% loss of holocellulose, a 22% loss of α-cellulose and 50% solubilization of protein. The nutritional value for the rat of wheat bran modified by either enzyme combination was significantly improved. Apparent protein digestibility was improved significantly. Preliminary experiments indicate that the modification of wheat bran increases the metabolizable energy.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Abhay Raj ◽  
Sharad Kumar ◽  
Sudheer Kumar Singh ◽  
Mahadeo Kumar

Providenciasp. strain X1 showing the highest xylanase activity among six bacterial isolates was isolated from saw-dust decomposing site. Strain X1 produced cellulase-free extracellular xylanase, which was higher in wheat bran medium than in xylan medium, when cultivated at pH 8.0 and 35°C. Zymogram analysis of crude preparation of enzymes obtained while growing on wheat bran and birchwood xylan revealed the presence of seven and two distinct xylanases with estimated molecular weight of 33; 35; 40; 48; 60; 75; and 95 kDa and 33 and 44 kDa, respectively. The crude xylanases were produced on wheat bran medium and showed optimum activity at pH 9.0 and 60°C. The thermotolerance studies showed activity retention of 100% and 85% at 40°C and 60°C after 30 min preincubation at pH 9.0. It was tolerant to lignin, ferulic acid, syringic acid, and guaiacol and retained 90% activity after ethanol treatment. The enzyme preparation was also tolerant to methanol and acetone and showed good activity retention in the presence of metal ions such as Fe2+, Mg2+, Zn2+, and Ca2+. The crude enzyme preparation was classified as endoxylanase based on the product pattern of xylan hydrolysis. Pretreatment of kraft pulp with crude xylanases for 3 h at 60°C led to a decrease in kappa number by 28.5%. The properties of present xylanases make them potentially useful for industrial applications.


1961 ◽  
Vol 7 (1) ◽  
pp. 33-44 ◽  
Author(s):  
D. W. S. Westlake ◽  
F. J. Simpson

A synthetic medium containing 0.4% rutin, 0.3% (NH4)2HPO4, 0.1% KH2PO4, 0.1% MgCl2∙6H2O, and 0.8% (NH4)2SO4was developed for the production of the extracellular enzyme system that degrades rutin. The total amount of the enzyme system produced is approximately the same between 25 and 35 °C but the rate is more rapid at the higher temperature. Aeration is necessary both for synthesis and for excretion into the medium, excretion apparently being more sensitive than synthesis. Magnesium is required for growth and sulphate for release of the enzyme system into the medium. Calcium carbonate depresses both growth and production. The medium has been successfully employed for production in 5-gallon fermentors of the extracellular enzymes that degrade rutin.


1955 ◽  
Vol 1 (9) ◽  
pp. 733-742 ◽  
Author(s):  
A. Dalby ◽  
A. C. Blackwood

Cell-free extracts of Aerobacter aerogenes grown on a medium containing yeast extract, glucose, and salts, oxidized D-α-fructoheptose (2-C-hydroxymethyl-D-glucose), glucose, gluconate, and other hexoses and pentoses. The enzymes were in a particulate fraction and were difficult to purify. This cell-free enzyme system required magnesium or certain other divalent metal ions as activators and was not stimulated by any coenzyme tested. Phosphorylation did not appear to be involved. The pH-stability and pH-activity curves for the crude enzyme preparation were plotted and the Kmvalue for D-α-fructoheptose determined. The same enzyme system is apparently involved for all substrates and appears to be specific for sugars having the same configuration as glucose at the second and fourth carbon atoms.


2001 ◽  
Vol 56 (11-12) ◽  
pp. 1022-1028 ◽  
Author(s):  
Kristina Uzunova ◽  
Anna Vassileva ◽  
Margarita Kambourova ◽  
Viara Ivanova ◽  
Dimitrina Spasova ◽  
...  

Abstract Enzyme production of newly isolated thermophilic inulin-degrading Bacillus sp. 11 strain was studied by batch cultivation in a fermentor. The achieved inulinase and invertase activi­ ties after a short growth time (4.25 h) were similar or higher compared to those reported for other mesophilic aerobic or anaerobic thermophilic bacterial producers and yeasts. The investigated enzyme belonged to the exo-type inulinases and splitted-off inulin, sucrose and raffinose. It could be used at temperatures above 65 °C and pH range 5.5-7.5. The obtained crude enzyme preparation possessed high thermostability. The residual inulinase and inver­ tase activities were 92-98% after pretreatment at 65 °C for 60 min in the presence of substrate inulin.


Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2257-2266 ◽  
Author(s):  
Helmuth Adelsberger ◽  
Christian Hertel ◽  
Erich Glawischnig ◽  
Vladimir V. Zverlov ◽  
Wolfgang H. Schwarz

Four extracellular enzymes of the thermophilic bacterium Clostridium stercorarium are involved in the depolymerization of de-esterified arabinoxylan: Xyn11A, Xyn10C, Bxl3B, and Arf51B. They were identified in a collection of eight clones producing enzymes hydrolysing xylan (xynA, xynB, xynC), β-xyloside (bxlA, bxlB, bglZ) and α-arabinofuranoside (arfA, arfB). The modular enzymes Xyn11A and Xyn10C represent the major xylanases in the culture supernatant of C. stercorarium. Both hydrolyse arabinoxylan in an endo-type mode, but differ in the pattern of the oligosaccharides produced. Of the glycosidases, Bxl3B degrades xylobiose and xylooligosaccharides to xylose, and Arf51B is able to release arabinose residues from de-esterified arabinoxylan and from the oligosaccharides generated. The other glycosidases either did not attack or only marginally attacked these oligosaccharides. Significantly more xylanase and xylosidase activity was produced during growth on xylose and xylan. This is believed to be the first time that, in a single thermophilic micro-organism, the complete set of enzymes (as well as the respective genes) to completely hydrolyse de-esterified arabinoxylan to its monomeric sugar constituents, xylose and arabinose, has been identified and the enzymes produced in vivo. The active enzyme system was reconstituted in vitro from recombinant enzymes.


2013 ◽  
Vol 34 (3) ◽  
pp. 253-267 ◽  
Author(s):  
Mauro Tropeano ◽  
Susana Vázquez ◽  
Silvia Coria ◽  
Adrián Turjanski ◽  
Daniel Cicero ◽  
...  

AbstractCold−adapted marine bacteria producing extracellular hydrolytic enzymes are important for their industrial application and play a key role in degradation of particulate organic matter in their natural environment. In this work, members of a previously−obtained protease−producing bacterial collection isolated from different marine sources from Potter Cove (King George Island, South Shetlands) were taxonomically identified and screened for their ability to produce other economically relevant enzymes. Eighty−eight proteolytic bacterial isolates were grouped into 25 phylotypes based on their Amplified Ribosomal DNA Restriction Analysis profiles. The sequencing of the 16S rRNA genes from representative isolates of the phylotypes showed that the predominant culturable protease−producing bacteria belonged to the class Gammaproteobacteria and were affiliated to the genera Pseudomonas, Shewanella, Colwellia, and Pseudoalteromonas, the latter being the predominant group (64% of isolates). In addition, members of the classes Actinobacteria, Bacilli and Flavobacteria were found. Among the 88 isolates screened we detected producers of amylases (21), pectinases (67), cellulases (53), CM−cellulases (68), xylanases (55) and agarases (57). More than 85% of the isolates showed at least one of the extracellular enzymatic activities tested, with some of them producing up to six extracellular enzymes. Our results confirmed that using selective conditions to isolate producers of one extracellular enzyme activity increases the probability of recovering bacteria that will also produce additional extracellular enzymes. This finding establishes a starting point for future programs oriented to the prospecting for biomolecules in Antarctica.


2013 ◽  
Vol 10 (1) ◽  
pp. 567-582 ◽  
Author(s):  
S. Endres ◽  
J. Unger ◽  
N. Wannicke ◽  
M. Nausch ◽  
M. Voss ◽  
...  

Abstract. The filamentous and diazotrophic cyanobacterium Nodularia spumigena plays a major role in the productivity of the Baltic Sea as it forms extensive blooms regularly. Under phosphorus limiting conditions Nodularia spumigena have a high enzyme affinity for dissolved organic phosphorus (DOP) by production and release of alkaline phosphatase. Additionally, they are able to degrade proteinaceous compounds by expressing the extracellular enzyme leucine aminopeptidase. As atmospheric CO2 concentrations are increasing, we expect marine phytoplankton to experience changes in several environmental parameters, including pH, temperature, and nutrient availability. The aim of this study was to investigate the combined effect of CO2-induced changes in seawater carbonate chemistry and of phosphate deficiency on the exudation of organic matter, and its subsequent recycling by extracellular enzymes in a Nodularia spumigena culture. Batch cultures of Nodularia spumigena were grown for 15 days under aeration with low (180 μatm), medium (380 μatm), and high (780 μatm) CO2 concentrations. Obtained pCO2 levels in the treatments were on median 315, 353, and 548 μatm CO2, respectively. Extracellular enzyme activities as well as changes in organic and inorganic compound concentrations were monitored. CO2 treatment–related effects were identified for cyanobacterial growth, which in turn influenced the concentration of mucinous substances and the recycling of organic matter by extracellular enzymes. Biomass production was increased by 56.5% and 90.7% in the medium and high pCO2 treatment, respectively, compared to the low pCO2 treatment. In total, significantly more mucinous substances accumulated in the high pCO2 treatment, reaching 363 μg Xeq L−1 compared to 269 μg Xeq L−1 in the low pCO2 treatment. However, cell-specific rates did not change. After phosphate depletion, the acquisition of P from DOP by alkaline phosphatase was significantly enhanced. Alkaline phosphatase activities were increased by factor 1.64 and 2.25, respectively, in the medium and high compared to the low pCO2 treatment. We hypothesise from our results that Nodularia spumigena can grow faster under elevated pCO2 by enhancing the recycling of organic matter to acquire nutrients.


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