scholarly journals Effect of Metal Ions, Chemical Agents, and Organic Solvent on Bacillus Sp.R2 Chitinase Activity

2016 ◽  
Vol 22 ◽  
pp. 465-470 ◽  
Author(s):  
Ben Amar Cheba ◽  
Taha Ibrahim Zaghloul ◽  
Mohamad Hisham EL-Massry ◽  
Ahmad Rafik EL-Mahdy
CrystEngComm ◽  
2021 ◽  
Author(s):  
Lihong Zhou ◽  
Guanghui Wang ◽  
Jie Du ◽  
Qinjiang Zhao ◽  
Xiang Pei

The system of organic solvent and ligand had been successfully applied to regulate the coordination of metal ions in organic chemistry. Inspired by previous works, we had conducted the study...


2013 ◽  
Vol 726-731 ◽  
pp. 1872-1878 ◽  
Author(s):  
Jun Xia Liu ◽  
Bing Zhi Dong ◽  
Yun Ge Sheng ◽  
Ji Ping Wang

The main objective of this study was to investigate foulants in chemical cleaning solutions of membrane (CCSM). Sodium hydroxide (NaOH), sodium hypochlorite (NaOCl), hydrochloric acid (HCl) were used as chemical agents respectively. Hydrophobicity, molecular weight distribution and metal ions of foulants in CCSM were analyzed as the major characters for membrane fouling. Results reveal that alkali cleaning can remove both hydrophobic and hydrophilic fractions of natural organic matters (NOM), and acid cleaning mainly removes hydrophilic organic matters. Medium molecular weight of very hydrophobic acids (1-10 kDa) and different molecular weight of neutral hydrophilic acids (100-1000 Da & >300kDa) in NOM can lead to membrane irreversible fouling. Acid cleaning is relatively effective for the reduction of inorganic foulants. The main metal ions in acid cleaning solutions are K ,Ca, Al and Mn, which are responsible for membrane inorganic fouling.


Author(s):  
Nuha Y. Elamin ◽  
Elmugdad Ahmed Ali

The hydroxamic acid was prepared by the partial reduction of p- nitro toluene to give N-p-tolyl hydroxyl amine which was coupled with benzoyl chloride to give N-p-tolyl-N-benzohydroxamic acid.The hydroxamic acid prepared was identified by their characteristic colored reaction with vanadium (V) and iron (lll), melting point, I.R.  spectra, 1H NMR and mass spectrometry.The extractive properties of hydroxamic acids towards the metal ions like Fe (lll), Cu (ll), Ni (ll) and Co (ll) were examined using appropriate organic solvent. N-p- tolyl -N-benzohydroxamic acid was found to have a maximum extraction for Fe (lll) 75.10% at pH 5.0, Cu (ll) 99.81% at pH 5.0, Ni (ll) 59.45% at pH 7.0 and Co (ll) 99.40% at pH 10.0.The  hydroxamic acid was found to extract efficiently metals like Ni (ll) in neutral pH values, Fe (lll), Cu (ll), in pH near to neutral and Co (ll) at alkali pH values.


2021 ◽  
Vol 19 (3) ◽  
pp. 509-517
Author(s):  
Nguyen Khanh Hoang Viet ◽  
Ha Thi Thuy Hoa ◽  
Truong Nam Hai ◽  
Do Thi Huyen

A gene coding for GH5 endoglucanase exploited from metagnomic DNA data of bacteria in Vietnamese goats’ rumen was modularity structure including a catalytic module, a fibronectin-3 like module and an X module. The recombinant enzyme was sucessfully expressed in E. coli and purified.  To study the effect of some metal ions and chemicals on enzyme activity, in this study, we used some tools including Swiss-Prot, ProFunc, COFACTOR for prediction of enzyme structure and ligands interaction. The obtained results indicated that the most similar structure with enzyme had two conserved residues (Asp-190 và Asp-192) linked with Mn2+ within a radius of ~ 3.5 Å from the center of ion Mn2+ and enzyme molecule contained a disulphide bond. Experimental results for essessment of the effect of some metal ions (Ca2 +, Mn2 +, Mg2+, Ni2+, K+, Co2+, Cu2+, Zn2+, Fe3+) at the final concentration of 10 mM and of six common chemicals including SDS (1%), urea (1 µM), 2-mercaptoethanol (1 µM), EDTA (1 µM), tween 80 (1mM), triton X-100 (1 µM) showed that only Mn2+ increased enzyme activity slightly at concentration of 10 mM and two times at the concentration of 40 mM Mn2+. The Mn2+ has been identified as a specific binding agent may increase the stability and activity of endoglucanase GH5.


Talanta ◽  
1972 ◽  
Vol 19 (12) ◽  
pp. 1654-1658 ◽  
Author(s):  
J. Korkisch ◽  
M.M. Khater

2008 ◽  
Vol 62 (3) ◽  
pp. 687-693 ◽  
Author(s):  
Guilherme Dias Rodrigues ◽  
Maria do Carmo Hespanhol da Silva ◽  
Luis Henrique Mendes da Silva ◽  
Fernanda Jürgensen Paggioli ◽  
Luis Antonio Minim ◽  
...  

2015 ◽  
Vol 51 (18) ◽  
pp. 3743-3746 ◽  
Author(s):  
Yuta Saito ◽  
Hiroshi Yabu

We proposed a block copolymer PDHSt-b-PSt, that contains catechol groups in side chains of PDHSt moieties. The block copolymer was used as a reductant to synthesize organic-solvent-dispersive Ag NPs.


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