scholarly journals Engineering a recombination neutral protease I from Aspergillus oryzae to improve enzyme activity at acidic pH

RSC Advances ◽  
2020 ◽  
Vol 10 (51) ◽  
pp. 30692-30699
Author(s):  
Yucheng Hu ◽  
Tong Li ◽  
Zhui Tu ◽  
Qinghua He ◽  
Yanping Li ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Aspergillus Oryzae ◽  
Neutral Protease ◽  
Acidic Ph ◽  
Soybean Proteins ◽  
Neutral Proteases

Extracellular neutral proteases (NPs) in Aspergillus oryzae (A. oryzae) play a role in hydrolyzing soybean proteins into smaller peptides at pH about 7.5.

Improvement of the quality of soy sauce by reducing enzyme activity in Aspergillus oryzae

2019 ◽  
Vol 292 ◽  
pp. 81-89 ◽  
Author(s):  
Chengfang Ding ◽  
Meng Meng ◽  
Yuyang Jiang ◽  
Lihua Hou
Keyword(s):  
Enzyme Activity ◽  
Aspergillus Oryzae ◽  
Soy Sauce

scholarly journals Biochemical studies on the activity of δ-(l-α-aminoadipyl)-l-cysteinyl-d-valine synthetase from Streptomyces clavuligerus

1992 ◽  
Vol 283 (3) ◽  
pp. 691-698 ◽  
Author(s):  
J Zhang ◽  
S Wolfe ◽  
A L Demain
Keyword(s):  
Enzyme Activity ◽  
High Temperature ◽  
Bioactive Compounds ◽  
Streptomyces Clavuligerus ◽  
Synthetase Activity ◽  
Enzyme Specificity ◽  
Acidic Ph ◽  
Reaction Parameters ◽  
Biochemical Studies ◽  
Isopenicillin N

The enzyme activity of purified delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) synthetase from Streptomyces clavuligerus was studied biochemically. The dependence of ACV synthetase activity on reaction parameters, including substrates, cofactors, temperature and pH, were determined, resulting in a substantially increased enzyme activity. The activity is very labile to high temperature and is also unstable at acidic pH. The enzyme specificity is strict towards L-alpha-aminoadipate, but rather loose with respect to L-valine; certain modifications of L-cysteine can also be tolerated. Some unnatural tripeptides synthesized by ACV synthetase can be converted into bioactive compounds by isopenicillin N synthase. The only nutrient found to negatively affect ACV synthetase activity is phosphate, but various compounds such as thiol-blocking reagents and ATP-utilization products (AMP and pyrophosphate) are inhibitory to the enzyme.

Responses of the phosphatase activity of the lichen Cladina rangiferina to various environmental factors including metals

1979 ◽  
Vol 57 (14) ◽  
pp. 1534-1540 ◽  
Author(s):  
I. Lane ◽  
K. J. Puckett
Keyword(s):  
Enzyme Activity ◽  
Environmental Factors ◽  
Phosphatase Activity ◽  
Enzyme Activities ◽  
Enzyme Concentration ◽  
Acidic Ph ◽  
Nitrophenyl Phosphate ◽  
Cladina Rangiferina ◽  
Reduced Activity ◽  
Menten Constant

The characteristics of phosphatase activity of Cladina rangiferina (L.) Harm, have been studied. Calculations of enzyme activities were based on the liberation of p-nitrophenol from p-nitrophenyl phosphate. The phosphatase activity was found to be linear both with increasing sample size (enzyme concentration) and increasing time, showed highest activity at acidic pH, and had a Michaelis–Menten constant of 8.9 × 10−3 M. The enzyme activity was maximal in the range 61 ± 10 °C, was independent of light, and was completely eliminated by boiling the thalli. Various cations and anions were tested for their effect; uranyl and vanadyl ions inhibited activity by 60% whereas copper, nickel, and silver enhanced activity by 10%. The anions biselenite, cyanide, fluoride, molybdate, phosphate, and vanadate all greatly reduced activity (≥ 50%). Phosphatase activity was demonstrated in other lichen species.

scholarly journals Intensifying the Fermentation of Aspergillus oryzae in a Stirred Bioreactor Using Maxblend Impeller

2016 ◽  
Vol 10 (1) ◽  
pp. 88-109 ◽  
Author(s):  
Narges Ghobadi ◽  
Chiaki Ogino ◽  
Naoto Ohmura
Keyword(s):  
Growth Rate ◽  
Enzyme Activity ◽  
Power Consumption ◽  
Aspergillus Oryzae ◽  
Rushton Turbine ◽  
Stirred Bioreactor ◽  
Condition Effect ◽  
Batch Condition ◽  
Fermentation Parameters ◽  
Stirred Bioreactors

Background: The intensification of fermentation in stirred bioreactors is an attractive approach for commercial interests and industries that work with biochemical products. Alpha amylase is an enzymatic bio-products that is produced largely from Aspergillus oryzae. Using adaptable agitator can be an efficient way for stirred fermentation. Objective: This study, concentrated on enhancing the mixing process in order to intensify Aspergillus oryzae fermentation. A straight type of Maxblend® impeller was used as an agitator to investigate the incubation parameters compared with the use of a 6-blade double Rushton turbine. Method: Stirred fermentation was done in batch condition. Effect of flow pattern of mixing on fermentation parameters was investigated after each sampling. Results: The results showed that the Maxblend® significantly intensified both enzyme activity and growth rate at low and moderate rates of power consumption (P). The main reason for the decreases in the growth rate and the enzyme activity during agitation by the Rushton turbine at low and high Pv was the lack of oxygen and mycelial damage, respectively. Additionally, use of the Maxblend® significantly intensified the KLa at low and moderate rates of power consumption. Conclusion: Axial and uniform mixing by Maxblend® impeller was resulted in improving the fermentation characteristics and enzyme activity.

scholarly journals Crystal structures of Aspergillus oryzae Rib2 deaminase: the functional mechanism involved in riboflavin biosynthesis

IUCrJ ◽  
2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Sheng-Chia Chen ◽  
Li-Ci Ye ◽  
Te-Ming Yen ◽  
Ruei-Xin Zhu ◽  
Cheng-Yu Li ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
High Resolution ◽  
Protein Stability ◽  
Crystal Structures ◽  
Aspergillus Oryzae ◽  
Terminal Segment ◽  
Riboflavin Biosynthesis ◽  
The Third ◽  
Complex Forms ◽  
Deaminase Domain

Riboflavin serves as the direct precursor of the FAD/FMN coenzymes and is biosynthesized in most prokaryotes, fungi and plants. Fungal Rib2 possesses a deaminase domain for deamination of pyrimidine in the third step of riboflavin biosynthesis. Here, four high-resolution crystal structures of a Rib2 deaminase from Aspergillus oryzae (AoRib2) are reported which display three distinct occluded, open and complex forms that are involved in substrate binding and catalysis. In addition to the deaminase domain, AoRib2 contains a unique C-terminal segment which is rich in charged residues. Deletion of this unique segment has no effect on either enzyme activity or protein stability. Nevertheless, the C-terminal αF helix preceding the segment plays a role in maintaining protein stability and activity. Unexpectedly, AoRib2 is the first mononucleotide deaminase found to exist as a monomer, perhaps due to the assistance of its unique longer loops (Lβ1–β2, LαB–β3 and LαC–β4). These results form the basis for a molecular understanding of riboflavin biosynthesis in fungi and might assist in the development of antibiotics.

scholarly journals The Action of Peptidases from Aspergillus oryzae in Digestion of Soybean Proteins

1972 ◽  
Vol 36 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Tadanobu NAKADAI ◽  
Seiichi NASUNO ◽  
Nobuyoshi IGUCHI
Keyword(s):  
Aspergillus Oryzae ◽  
Soybean Proteins

Glycosylation analysis of recombinant neutral protease I from Aspergillus oryzae expressed in Pichia pastoris

2013 ◽  
Vol 35 (12) ◽  
pp. 2121-2127 ◽  
Author(s):  
Da Lei ◽  
Yang Xu ◽  
Qinghua He ◽  
Yifeng Pan ◽  
Bo Chen ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Aspergillus Oryzae ◽  
Neutral Protease
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