scholarly journals Isolation of Xylanase Producing Strains, Optimization of Fermentation Conditions and Research on Enzymatic Properties

2021 ◽  
Vol 12 (2) ◽  
pp. 1
Author(s):  
Ji Huilong ◽  
Gao Xin ◽  
WU Wenxuan ◽  
Ma Zhuang ◽  
Qing Qing
Keyword(s):  
Enzyme Activity ◽  
Specific Activity ◽  
Ph Value ◽  
Fermentation Broth ◽  
Sodium Dodecyl ◽  
Alkali Resistance ◽  
Initial Ph ◽  
Acid And Alkali Resistance ◽  
Optimal Reaction Temperature ◽  
Optimization Of Fermentation

In this study, we successfully isolated a strain of Aspergillus oryzae TR08, which produced xylanase secreted to the outside of the cell productively. The enzyme activity and specific activity in the fermentation broth of this strain reached peak values of 451 IU/mL and 1963 IU/mg after 156 h of fermentation. A single factor experiment was designed, and it was found that the strain was adjusted to the initial pH of the fermentation broth to 7.5 in a shaker at 180 rpm and 32 °C. After 156 h of fermentation, the enzyme activity reached a maximum of 1264 IU/mL. The optimal reaction temperature and pH value of the xylanase were 55 °C and 7.5, respectively, and it had excellent acid and alkali resistance and a wide pH activity range. The xylanase was increased the catalytic activity by 15% in 0.25 mM Fe3+, and the biological activity of the enzyme was not affected in the sodium dodecyl sulfate environment.

scholarly journals Optimization of Fermentation Conditions for Cell Envelope Proteinase Produced by Lactobacillus Plantarum LP69

2021 ◽  
Vol 25 (1) ◽  
pp. 135-142
Author(s):  
Chi Zhang ◽  
He Chen ◽  
Ni Lei ◽  
Guanli Du ◽  
Xiangyun Li ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Specific Activity ◽  
Ph Value ◽  
Cell Envelope ◽  
Orthogonal Experiment ◽  
Initial Ph ◽  
Functional Peptides ◽  
Optimization Of Fermentation ◽  
Single Factor Experiment ◽  
Hydrolyze Casein

Abstract Cell-envelope proteinases (CEPs) can hydrolyze casein into functional peptides, which is beneficial to the health of the host. The single factor experiment screened out that the optimal conditions for CEP production by Lactobacillus plantarum LP69 were 37°C, 20h, initial pH of 7, and optimal inoculation amount of 5%. The best conditions for this experiment were obtained by orthogonal experiment: time 22h, temperature 39°C, initial pH value of 6, and inoculation amount of 5%. Under this culture condition, the target protease activity of Lactobacillus plantarum LP69 reached 22.31±0.82U/mL, the protein content was 19.07±0.36mg/mL, and the specific activity was 1.17±0.06U/mg. The specific activity significantly increased by 15.8% compared with the control (p<0.05).

scholarly journals The Removal of Methylene Blue Dye from Aqueous Solutions Using Activated and Non-Activated Bentonites

2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah
Keyword(s):  
Methylene Blue ◽  
Ph Value ◽  
Sodium Dodecyl ◽  
Freundlich Isotherm ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Ionic Surfactant ◽  
Methylene Blue Dye ◽  
X Ray Diffraction ◽  
Initial Ph

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.

scholarly journals Pre-fermentative treatment of a model wine with aim to serve as a functional food with decreased alcohol content

2017 ◽  
Vol 63 (01) ◽  
pp. 47-53
Author(s):  
Irina Mladenoska ◽  
Verica Petkova ◽  
Tatjana Kadifkova Panovska
Keyword(s):  
Enzyme Activity ◽  
Gluconic Acid ◽  
Functional Food ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Alginate Beads ◽  
High Concentration ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Initial Ph

The effect of substrate concentration on the enzyme activity in the reaction of glucose conversion into gluconic acid was investigated by using three different enzyme preparations in media with two different glucose concentrations. The media were simulating the conditions in the must, thus named as minimal model must, and were composed form combination of several organic acids and glucose. Those media were having initial pH of 3.5 that is a very unfavorable for glucose oxidase activity having a pH optimum at the pH value of 5.5. Among the three preparations used, the bakery additive, Alphamalt Gloxy 5080, was the most active in the medium with glucose concentration of 10 g/L, showing conversion of more than 70% for the period of 24 h, while the same enzyme preparation in the medium with 100 g/L glucose converted only about 7% of glucose. The pH value of the medium at the beginning and at the end of the enzymatic reaction was a good indicator of the enzyme activity. It seems that for the conversion of glucose in higher concentration, enzymatic preparation in high concentration should also be used. The preliminary attempt of immobilization of two preparations of glucose oxidases in alginate beads was also performed and a successful immobilization procedure for utilization in food industry was preliminarily developed. Keywords: glucose oxidases, enzymatic pretreatment, glucose, gluconic acid, model wine, functional food

A β-Mannanase from Bacillus subtilis B36: Purification, Properties, Sequencing, Gene Cloning and Expression in Escherichia coli

2006 ◽  
Vol 61 (11-12) ◽  
pp. 840-846 ◽  
Author(s):  
Ya Nan Li ◽  
Kun Meng ◽  
Ya Ru Wang ◽  
Bin Yao
Keyword(s):  
Escherichia Coli ◽  
Enzyme Activity ◽  
Bacillus Subtilis ◽  
Specific Activity ◽  
Ph Value ◽  
High Specificity ◽  
Apparent Molecular Weight ◽  
Cloning And Expression ◽  
Gene Cloning And Expression ◽  
Reading Frame

Abstract MANB36, a secrete endo-β-1,4-D-mannanase produced by Bacillus subtilis B36, was puri­fied to homogeneity from a culture supernatant and characterized. The optimum pH value for the mannanase activity of MANB36 is 6.4 and the optimum temperature is 50 °C. The enzyme activity of MANB36 is remarkably thermostable at 60 °C and the specific activity of MANB36 is 927.84 U/mg. Metal cations (except Hg2+ and Ag+), EDTA and 2-mercaptoetha- nol (2-ME) have no effects on enzyme activity. This enzyme exhibits high specificity with the substituted galactomannan locust bean gum (LBG). The gene encoding for MANB36, manB36, was cloned by PCR and sequenced. manB36 contains a single open reading frame (ORF) consisting of 1104 bp that encodes a protein of 367 amino acids. The predicted mo­lecular weight of 38.13 kDa, calculated by the deduced protein of the gene manB36 without signal peptide, coincides with the apparent molecular weight of 38.0 kDa of the purified MANB36 estimated by SDS-PAGE. The mature protein of MANB36 has been expressed in Escherichia coli BL21 and the expressed mannanase has normal bioactivity.

scholarly journals Cloning and Expression of Levansucrase Gene of Bacillus velezensis BM-2 and Enzymatic Synthesis of Levan

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 317
Author(s):  
Min Xu ◽  
Lixia Zhang ◽  
Fangkun Zhao ◽  
Jingyue Wang ◽  
Bo Zhao ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Specific Activity ◽  
Enzymatic Reaction ◽  
Production Capacity ◽  
Cloning And Expression ◽  
Buffer System ◽  
Bacterial Strains ◽  
Bacillus Velezensis ◽  
Fusion Enzymes ◽  
Optimal Reaction Temperature

Levan is a versatile and valuable fructose homopolymer, and a few bacterial strains have been found to produce levan. Although levan products have numerous specific functions, their application and promotion were limited by the production capacity and production cost. Bacillus velezensis BM-2 is a levan-synthesizing strain, but its levan production is too low to apply. In this study, the levansucrase gene of B. velezensis BM-2 was cloned to plasmid pET-32a-Acma-zz, and the recombinant plasmids were transferred to Escherichia coli BL21. A transformed clone was selected to express and secrete the fusion enzymes with an Acma-tag efficiently. The expressed products were further purified by a self-developed separating material called bacterial enhancer matrix (BEM) particles. The purification efficiency was 93.4%, with a specific activity of 16.589 U/mL protein. The enzymatic reaction results indicated that the optimal reaction temperature is 50 °C, the optimal pH of the acetate buffer is 5.6, and the buffer system greatly influenced the enzyme activity. The enzyme activity was enhanced to 130% in the presence of 5 mM Ca2+, K+, Zn2+, and Mn2+, whereas it was almost abolished in the case of Cu2+ and Fe3+. The values of Km, kcat, and kcat/Km were 17.41 mM, 376.83 s−1, and 21.64 mM−1s−1, respectively. The enzyme amount of 20 U/g sucrose was added to the system containing 400 g/L sucrose, and the levan products with a concentration of 120 g/L reached after an incubation of 18 h, which was 8 times that of the yield before optimization. The results of molecular docking analysis indicated that the Asp86 might act as a nucleophilic catalytic residue for sucrose, Arg246 and Asp247 act as transition state stabilizer of transfructosylation, and Glu340 and Arg306 were recognized as general acid donors. They formed the catalytic-groups triad. The unique properties and catalytic activity of the levansucrase suggest that it deserves further research and might have good industrial application prospects.

scholarly journals CHARACTERIZATION OF PARTIALLY PURIFIED TYROSINASE ISOLATED FROM BITTER KOLA (GARCINIA KOLA)

2022 ◽  
Author(s):  
B.O. Itakorode ◽  
O.E. Agboola ◽  
M.B. Adeboye ◽  
C.C. Benedict ◽  
K.N. Terkula ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Peer Review ◽  
Specific Activity ◽  
Ph Value ◽  
Inhibitory Effect ◽  
Enzymatic Browning ◽  
Partial Purification ◽  
Garcinia Kola ◽  
North East ◽  
Review Reports

Objective: Tyrosinase is a glycosylated, copper-containing oxidase that catalyzes the first two steps of mammalian melanogenesis as well as enzymatic browning events in damaged fruits during post-harvest handling and processing. Human skin hyperpigmentation and enzymatic browning in fruits are both undesirable. In this study, the properties and inhibitory effect of some compounds on bitter kola tyrosinase were investigated. Methods: Bitter kola tyrosinase was isolated and characterized using standard protocols. Partial purification was carried out on Sephadex G-100 loaded column chromatography.  Results: Bitter kola tyrosinase was purified with a specific activity of 3.5 U/mg protein, purification fold of 2.4 and a yield of 34%. The optimum pH value was found to be 6.0 while the optimum temperature value for maximum enzyme activity was observed at 60°C. The enzyme was stable at 40oC for 20 minutes. Metals such as NaCl, KCl, MgCl2 and CaCl2 had inhibitory effect on the activity; though MgCl2 and CaCl2 had minimal effect. Also, EDTA, β-marcaptoethanol and glutathione greatly inhibited the enzyme activity at all the tested concentration. Conclusion: The properties of bitter kola tyrosinase compare very well with the tyrosinase from other sources. Also, the study was able to establish the inhibitory effect of some compounds and this could be applied in food processing industries.                  Peer Review History: Received: 2 November 2021; Revised: 11 December; Accepted: 25 December, Available online: 15 January 2022 Academic Editor:  Dr. A.A. Mgbahurike, University of Port Harcourt, Nigeria, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency.  Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewers: Dr. Nazim Hussain, North East Frontier Technical University, Arunachal pradesh, India, [email protected] Ahmad Najib, Universitas Muslim Indonesia, Makassar, Indonesia, [email protected] Prof. Dr. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, [email protected] Similar Articles: PHYTOCHEMICAL PURIFICATION OF ACTIVE CONSTITUENTS ISOLATED FROM ROOT OF THE MEDICINAL HERB, CARALLUMA QUADRANGULA

scholarly journals Characteristics and kinetic analysis of β-glucosidase (MaBgl) from Mucor ardhlaengiktus RSC1

BioResources ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 1626-1638
Author(s):  
Zhihai Yang ◽  
Liping Wu ◽  
Mingjia Fu ◽  
Qin Li ◽  
Dexiao Ye
Keyword(s):  
Thermal Stability ◽  
Ph Value ◽  
Fermentation Broth ◽  
Hydrolytic Enzymes ◽  
Maximum Velocity ◽  
Exchange Chromatography ◽  
Cellulolytic Enzymes ◽  
Good Thermal Stability ◽  
Initial Ph ◽  
The Stability

Cellulolytic enzymes from fungi are complex compound enzyme structures that generally include three kinds of hydrolytic enzymes, which are called endo-β-1,4-glucanases, exo-β-1,4-glucanases, and β-1,4-glucosidases (β-glucosidases). The fungus Mucor ardhlaengiktus isolated from field rice straw produced a β-glucosidase (MaBgl). Maximal MaBgl production occurred when M. ardhlaengiktus was incubated for 6 days in fermentation liquor at 30 °C and an initial pH of 6. Purified MaBgl was obtained from M. ardhlaengiktus fermentation broth by ammonium sulfate fractional precipitation and DEAE-Sepharose FF ion exchange chromatography. The molecular weight of MaBgl as determined by SDS-PAGE electrophoresis was approximately 72 kDa. The kinetic parameters, Michaelis constant (Km) and maximum velocity (Vmax), of MaBgl were 78.2 μmol/L and 28.5 μmol/(L·min), respectively. Assays of MaBgl produced by M. ardhlaengiktus RSC1 under different conditions were investigated by the 3,5-dinitrosalicylic acid (DNS) assay for glucose. The pH and temperature optima for catalytic activity of MaBgl were pH 4.8 and 50 °C, respectively. MaBgl exhibited good thermal stability in the range of 20 to 30 °C, but the thermal stability of MaBgl decreased rapidly over 60 °C. MaBgl had better pH stability between pH 4.6 and 5.0, and the stability of MaBgl decreased when the pH value was lower or higher than this range.

scholarly journals Improving the Thermo-Activity and -Stability of Pectate Lyase from Dickeya dadantii DCE-01 for Ramie Degumming

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2106
Author(s):  
Huan Xu ◽  
Shengwen Duan ◽  
Xiangyuan Feng ◽  
Qi Yang ◽  
Ke Zheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Enzyme Activity ◽  
High Efficiency ◽  
Raw Materials ◽  
Fermentation Broth ◽  
Pectate Lyase ◽  
Site Directed Mutagenesis ◽  
Dickeya Dadantii ◽  
Enzyme Preparations ◽  
Optimal Reaction Temperature

To improve the thermal stability of pectate lyase for ramie degumming, we modified the novel pectate lyase gene (pelG403) derived from the Dickeya dadantii DCE-01 high-efficiency ramie degumming strain by site-directed mutagenesis. Twelve mutants were acquired, wherein a prospective mutant (A129V) showed better enzyme activity and thermal stability. Compared with the wild type (PelG403), the specific enzyme activity and the optimal reaction temperature of A129V in the fermentation broth increased by 20.1%, and 5 °C, respectively. Under the conditions of 55 °C and pH 9.0, the weightlessness rate of ramie raw materials of A129V increased by 6.26%. Therefore, this study successfully improved the enzyme activity and heat resistance of PelG403 in an alkaline environment, which may contribute to the development of enzyme preparations and the elucidation of the mechanism for ramie bio-degumming.

Inactivation of 6-phosphofructo-2-kinase during anaerobiosis in the marine whelk Busycon canaliculatum

1991 ◽  
Vol 260 (6) ◽  
pp. R1168-R1175
Author(s):  
L. Bosca ◽  
K. B. Storey
Keyword(s):  
Enzyme Activity ◽  
Protein Kinase ◽  
Molecular Mass ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Busycon Canaliculatum ◽  
Native Molecular Mass ◽  
Dependent Protein

6-Phosphofructo-2-kinase (PFK-2) was analyzed in four organs of the anoxia-tolerant marine gastropod mollusk Busycon canaliculatum. Whelk PFK-2 resembled the nonhepatic enzyme from mammals with highest activity occurring in gill (22 pmol.min-1.g-1). Hepatopancreas PFK-2 was purified over 8,000-fold to a final specific activity of 11 mU/mg protein (at 20 degrees C) and gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was a dimer with a native molecular mass of 142 kDa and a subunit molecular mass of 67 kDa. The purified enzyme showed negligible fructose-2,6-bisphosphatase (FBPase-2) activity, although the activity ratio of PFK-2 to FBPase-2 was 0.625 in crude extracts. In response to environmental anoxia, the activity of PFK-2 dropped in all organs to 34-56% of the corresponding aerobic value (half-time was 2 h in gill), and the Michaelis constant for fructose 6-phosphate increased by 50% (to 92 microM in gill). These changes paralleled decreases in organ fructose 2,6-bisphosphate concentration and pyruvate kinase activity and contribute to the overall glycolytic rate depression induced by anoxia in this facultative anaerobe. In vitro treatment of the anoxic form of hepatopancreas PFK-2 with alkaline phosphatase increased enzyme activity, suggesting that the aerobic and anoxic enzyme forms are interconverted by reversible protein phosphorylation. However, the protein kinase involved in this process is not yet known; incubation of aerobic PFK-2 with Mg-ATP plus adenosine 3',5'-cyclic monophosphate-dependent protein kinase or protein kinase C did not alter enzyme activity.

Molecular characterization of an endo-type chitosanase from the fish pathogenRenibacteriumsp. QD1

2014 ◽  
Vol 94 (4) ◽  
pp. 681-686 ◽  
Author(s):  
Peichuan Xing ◽  
Dan Liu ◽  
Wen-Gong Yu ◽  
Xinzhi Lu
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Specific Activity ◽  
Fermentation Broth ◽  
Maximal Activity ◽  
Optimum Temperature ◽  
Sds Page ◽  
Ph Range ◽  
Tlc Analysis

Renibacteriumsp. QD1, a bacteria strain capable of hydrolysing chitosan, was isolated from the homogenate of small crabs. An extracellular chitosanase, Csn-A, was purified from the QD1 fermentation broth. The enzyme was purified to homogeneity, with a yield of eight-fold, 67% recovery and a specific activity of 1575 U/mg proteins. The molecular weight of Csn-A was estimated to be 26.1 kDa by SDS-PAGE. Unlike other chitosanases, the purified Csn-A displayed maximal activity at a pH range of 5.3–6.5, and it was stable in a broad pH range of 5.0–10.0. The optimum temperature for chitosanlytic activity was 55°C. The enzyme activity was strongly stimulated by Mn2+but inhibited by Fe3+, Cu2+, Al3+, Zn2+and SDS. TLC analysis demonstrated that Csn-A hydrolysed N-deacetylated polymeric glucosamines into chito-biose and -triose in an endo-type manner. The amino acid seuquence of Csn-A showed close identity with an uncharacterized chitosanase of strain ATCC33209.

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