scholarly journals Purification and Enzymatic Properties of a New Thermostable Endoglucanase From Aspergillus Oryzae HML366

Author(s):  
Yongling Qin ◽  
Baoshan Qin ◽  
Yue Fu ◽  
Qiqian Li ◽  
Fengfeng Luo ◽  
...  

Abstract Aspergillus oryzae HML366 is a newly screened cellulase-producing strain. The endoglucanase HML ED1 from A. oryzae HML366 was quickly purified by two-step method ammonium sulfate precipitation and strong anion exchange column. SDS-PAGE electrophoresis indicated that the molecular weight of the enzyme was 68 kDa. The optimum temperature of the purified endoglucanase was 60 ℃ and the enzyme activity was stable below 70 ℃. The optimum pH was 6.5, and the enzyme activity was stable at pH between 4.5 to 9.0. The analysis indicated that additional Na+, K+, Ca2+, and Zn2+ reduced the catalytic ability of enzyme to the substrate, but Mn2+ enhanced its catalytic ability to the substrate.The Km and Vmax of the purified endoglucanase was 8.75 mg/mL and 60.24 μg/min·mL, respectively. Our study demonstrated that A. oryzae HML366 can produce a heat-resistant and wide pH tolerance endoglucanase HML ED1, which has potential industrial application value in bioethanol, paper, food, textile, detergent and pharmaceutical industries.

2019 ◽  
Vol 64 (4) ◽  
pp. 539-547
Author(s):  
Mohammed Inuwa Ja’afaru ◽  
Konjerimam Ishaku Chimbekujwo ◽  
Obinna Markraphael Ajunwa

Proteases are important industrial enzymes and fungi prove to be good sources of such enzymes. Purification techniques are however necessary for increased specificity in activity and better industrial value. Based on this, a protease produced by a Fusarium oxysporum was purified to homogeneity by Sephadex G-200 column and α–casein agarose chromatography. The enzyme had a molecular weight of 70 kDa in SDS-PAGE. Purified Fusarium oxysporum protease had a specific activity of 93.88 U/mg protein. The purification magnitude was 7.7 and the total yield was 20 %. Purified protease had an optimum pH of 5.0 while the optimum temperature was 40 °C. The enzyme was also thermotolerant (approximately 100 % at 40 °C for 2 h). The enzyme activity was stimulated by surfactants and metal ions like, Tween-20 and Mg2+. Enzyme activity was inhibited in presence of PMSF and EDTA. Casein was found to be the best substrate for protease activity of Fusarium oxysporum FWT1. Protease were tested upon blood stain for de-clotting of blood and was found to exhibit good de-clotting and de-staining activity after 15 minutes treatment time.


1992 ◽  
Vol 288 (2) ◽  
pp. 475-482 ◽  
Author(s):  
I Ishii-Karakasa ◽  
H Iwase ◽  
K Hotta ◽  
Y Tanaka ◽  
S Omura

For the purification of a new type of endo-alpha-N-acetylgalactosaminidase from the culture medium of Streptomyces sp. OH-11242 (endo-GalNAc-ase-S) [Iwase, Ishii, Ishihara, Tanaka, Omura & Hotta (1988) Biochem. Biophys. Res. Commun. 151, 422-428], a method for assaying enzyme activity was established. Using purified pig gastric mucus glycoprotein (PGM) as the substrate, oligosaccharides liberated from PGM were pyridylaminated, and the reducing terminal sugars of oligosaccharides larger than Gal beta 1-3GalNAc were analysed by h.p.1.c. The crude enzyme of endo-GalNAc-ase-S was prepared as an 80% (w/v) ammonium sulphate precipitate from the concentrated culture medium. The enzyme was partially purified by gel chromatofocusing and subsequent DEAE-Toyopearl chromatography. Endo-enzyme activity eluted around pI 4.8 on a gel chromatofocusing column and eluted with 0.19-0.25 M-NaCl on a DEAE-Toyopearl column. In the enzyme fraction obtained, no exo-glycosidases or proteases could be detected. The molecular mass of the enzyme was estimated as 105 kDa by gel filtration, and the optimum pH was 5.5. Endo-GalNAc-ase-S hydrolysed the O-glycosidic linkage between GalNAc and Ser (Thr) in 3H-labelled and unlabelled asialofetuin, liberating both the disaccharide (Gal beta 1-3GalNAc) and the tetrasaccharide [Gal beta 1-3 (Gal beta 1-4GlcNAc beta 1-6)GalNAc]. When endo-alpha-N-acetylgalactosaminidase from Alcaligenes sp. (endo-GalNac-ase-A) was incubated with 3H-labelled and unlabelled asialofetuin, only the disaccharide (Gal beta 1-3GalNAc) was liberated.


2021 ◽  
Vol 66 (1) ◽  
pp. 72-79
Author(s):  
Thuoc Doan Van ◽  
Hung Nguyen Phuc

The effect of physical parameters such as temperature and pH on the production, activity, and stability of α-amylase from Bacillus subtilis V37 was investigated. The results indicated that the optimum culture conditions for enzyme activity were pH 7.0 and 35 oC. The optimum pH and temperature for enzyme activity were 6.0 and 70 oC. The crude enzyme was found to be stable in the pH range of 5.0 to 7.0. The enzyme was stable for 1 h at a temperature from 30 to 80 oC; nearly 100% of enzyme activity remained at temperatures of 30 - 40 oC, and about 34% of original activity remained at a temperature of 80 oC. These features demonstrated that α-amylase from B. subtilis V37 can be applied in many areas such as the food, fermentation, and animal feed industries.


2014 ◽  
Vol 66 (3) ◽  
pp. 665-671 ◽  
Author(s):  
A.F.S. Nogueira ◽  
P.A. Di Filippo ◽  
L.A. Anai ◽  
M.C. Vieira ◽  
K.M.M.G. Simplício ◽  
...  

The initial inflammatory stages of the colic syndrome include changes known as acute phase response. The aim of this study was to contribute with the establishment of reference values concerning the electrophoretogram of peritoneal liquid from healthy horses and horses submitted to experimentally induced intestinal obstruction. Twenty-one horses were allotted in four groups: duodenal obstruction (DG), ileum obstruction (IG), left-dorsal colon obstruction (MG), and control group (CG). Peritoneal liquid was sampled before obtruction (T0), with 3 hours of obstruction (T3) and 6, 30, 102 and 174 hours after desobstructing (T6, T30, T102 and T174, respectively). Total protein levels were determined by the biuret method and protein fractions were obtained by SDS-PAGE electrophoresis. The acute phase proteins (APP) identified were Immunoglobulin-A, ceruloplasmin, transferrin, albumin, α1-antitrypsin, heavy and light chains of immunoglobulin-G, haptoglobin, α1-acid glycoprotein and a still unnamed protein, which was called P24. There was no difference (P>0.3) in protein levels among groups, although a significant difference (P>0.05) was observed between distinct experimental moments in each group evidencing a higher response of the APP in the obstructed groups. The APP fractioning of the peritoneal liquid was standardized to establish a standard curve for healthy equines and those submitted to induced intestinal obstruction. Moreover, it was verified that the SDS-PAGE electrophoresis was sensitive and effective to help diagnose abdominal inflammatory processes.


1950 ◽  
Vol 28e (3) ◽  
pp. 69-79 ◽  
Author(s):  
R. J. Rossiter ◽  
Esther Wong

Rabbit polymorphonuclear leucocytes contain an enzyme capable of hydrolyzing biosynthetic phenolphthalein mono-β-glucuronide. The concentration of the enzyme in the white cell is some 2000 times the concentration of the enzyme in the blood plasma. Under the conditions of study, the β-glucuronidase activity was proportional to the concentration of the enzyme. The effect of substrate concentration on the enzyme activity was studied and the Michaelis constant, Ks, determined. The course of the reaction was linear with time for the first 12 hr. and then fell off slightly during the next 12 hr. The optimum pH of the enzyme was 4.45 in either 0.2 M acetate or 0.2 M phthalate buffer. It was not inhibited by cyanide, azide, iodoacetate, fluoride, glycine, thiourea, urethane, arsanilic acid, acetophenone, o-cresol or m-cresol, in a final concentration of 0.01 M. The possible function of β-glucuronidase in rabbit polymorphonuclear leucocytes is discussed.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1610 ◽  
Author(s):  
Jia Li ◽  
Chao Cai ◽  
Mengmeng Zheng ◽  
Jiejie Hao ◽  
Ya Wang ◽  
...  

The purpose of this study is to develop a robust approach to obtain β glucans from Lentinus edodes and to characterize their structural and biological properties for sustainable utilization. The alkali extraction was optimized with an orthogonal experimental design, and a concise process for obtaining specific targeting polysaccharides from Lentinus edodes was developed in this study. After purification with a Q-Sepharose Fast Flow strong anion-exchange column, the monosaccharide composition, a methylation analysis, and NMR spectroscopy were employed for their structural characterizations. LeP-N2 was found to be composed of (1→6)-β-d-glucans with minor β-(1→3) glucosidic side chains. Atomic force microscopy (AFM) and high-performance gel permeation chromatography–refractive index–multi-angle laser light scattering (HPGPC-RI-MALLS) also revealed LeP-N2 exhibiting a compact unit in aqueous solution. This (1→6)-β-d-glucan was tested for antioxidant activities with IC50 at 157 μg/mL. Moreover, RAW 264.7 macrophage activation indicated that the release of nitric oxide (NO) and reactive oxygen species (ROS) was markedly increased with no cytotoxicity at a dose of 100 μg/mL. These findings suggest that the (1→6)-β-d-glucans obtained from Lentinus edodes could serve as potential agents in the fields of functional foods or medicine.


Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Ingrida Radveikienė ◽  
Ingrida Pilotaitė ◽  
Rimgailė Dainytė ◽  
Regina Vidžiūnaitė

Novel fungal laccase isoenzymes (namely L95-1 and L95-2) produced by the Ascomycete Lithothelium sp. isolated from the forest soil were purified. However, only one of them was characterized, because the other isoenzyme lost its activity during purification. Extracellular L95-1 laccase was purified 30-fold using ion-exchange and hydrophobic interaction chromatography, with an overall yield of 88%. The molecular mass of purified L95-1 was estimated to be 85 kDa by SDS-PAGE analysis. L95-1 laccase was stable at temperature 4–22°C and pH 6.0–6.5. The substrate specificity of L95-1 laccase was examined with various compounds. Determined affinity constants (KM) varied in a wide range of 3.7–2020.0 µM, whereas catalytic efficiency constants (kcat/KM) covered a range of 0.008–1.9 µM–1 s–1. The optimum pH for most substrates varied in a range from pH 5.0 to 6.0. Sodium azide and fluoride strongly inhibited L95-1 activity, whereas sulphate salts inhibited weakly. The laccase was immobilized on the Fe3O4 nanoparticles and characterized. Residual activity remained at 20% after ten cycles of ABTS oxidation reaction. The immobilized laccase showed higher tolerance to various metal salts. The properties of L95-1 laccase make it potentially useful in the biotechnological applications.


Author(s):  
Emi Latifah ◽  
Putri Dwi Mulyani ◽  
Yekti Asih Purwestri

Bacteria BSR 2, Pseudomonas alcaligenes (BSR 3), Brevibacillus parabrevis (BSR 8), Brevibacillus sp. (BSR 9), isolated from termite gut and Bacillus licheniformis (BSA B1) isolated from milkfish gut have been known to possess celluloytic activity. However, their lignolytic ability has not been known. This study aimed to determine the lignolytic ability of bacteria isolated from termit (Coptotermes sp.) and milkfish (Chanos chanos Forsskal, 1775) guts and their enzymes characterization. The qualitative test was done through the spot test method, while quantitative assay was performed spectrophotometrically at 335 nm to calculate vanillin concentration. The isolates were grown in Lignin Mineral Medium, then the optical density (OD620) were measured every 24 hours for 5 days using spectrophotometer to determine their growth profile and the best isolation time of the lignolytic enzyme. Based on results, the best lignolytic enzyme isolation time for strains Bacillus licheniformis (BSA B1) and BSR 2 were 5 days, yielding lignolytic enzyme activity of 0.961 ± 0.168 U/mg and 2.176 ± 0.088 U/mg respectively,  while strains Pseudomonas alcaligenes (BSR 3), Brevibacillus parabrevis (BSR 8), and Brevibacillus sp. (BSR 9) were 4 days, yielding of 1.206 ± 0.045 U/mg, 1.162 ± 0.191 U/mg, and 0.896 ± 0.108 U/mg, respectively. The strain BSR 2 showed the highest lignolytic activity compared to other strains. The optimum temperature for lignolytic enzyme activity of BSR 2 was 30 ℃ and the optimum pH was 7. The lignolytic enzyme activity showed that these bacterial isolates can be a chance to be used as new alternative lignolytic enzyme source in commercial bioconversion process.


1999 ◽  
Vol 181 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Hisayo Ono ◽  
Kazuhisa Sawada ◽  
Nonpanga Khunajakr ◽  
Tao Tao ◽  
Mihoko Yamamoto ◽  
...  

ABSTRACT 1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic β-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with l-glutamate. This enzyme required pyridoxal 5′-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25°C and had Km s of 9.1 mM forl-glutamate and 4.5 mM for dl-ASA. DABA acetyltransferase catalyzed acetylation of DABA to γ-N-acetyl-α,γ-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20°C in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15°C in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0.77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30°C.


2019 ◽  
pp. 17-20
Author(s):  
Hilal Ebru Çakır ◽  
Yakup Şirin ◽  
Sevgi Kolaylı

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