scholarly journals Glycerol Carbonate: A Novel Biosolvent with Strong Ionizing and Dissociating Powers

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Guangnan Ou ◽  
Biyan He ◽  
Xuejing Li ◽  
Jianhui Lei
Keyword(s):  
Bacillus Subtilis ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Protein Denaturation ◽  
Nonaqueous Solvents ◽  
Ionization Constants ◽  
Glycerol Carbonate ◽  
Protonation State ◽  
Liquid Media ◽  
Ionizable Groups

The activity of biocatalysts in nonaqueous solvents is related to the interaction of organic solvents with cells or enzymes. The behavior of proteins is strongly dependent on the protonation state of their ionizable groups, which ionization constants are greatly affected by the solvent. Due to the weak ionizing and dissociating powers of common organic solvents, the charge of the protein will change significantly when the protein is transferred from water to common organic solvents, resulting in protein denaturation. In this work, glycerol carbonate (GC) was synthesized, which ionizing and dissociating abilities were very close to those of water. Transesterification activities ofCandida antarcticalipase B (CALB) in GC were comparable to those in water and remained constant during 4-week storage.Bacillus subtilisandSaccharomyecs cerevisiaewere cultured in liquid media containing GC with test tubes. In the medium containing low GC concentration,Bacillus subtilisandSaccharomyecs cerevisiaegrew well as in a medium containing no organic solvent, but, in the medium containing high GC concentration, the growth ofBacillus subtilisandSaccharomyecs cerevisiaewas suppressed. The results suggested that GC is a potential biosolvent, which has great significance to biocatalysis in nonaqueous solvents.

scholarly journals a PRODUCTION OF PROTEASE FROM BACILLUS SUBTILIS UNDER SSF AND EFFECT OF ORGANIC SOLVENTS ON LYOPHILIZED PROTEASE PREPARATIONS

2020 ◽  
pp. 1-17
Author(s):  
SELMIHAN SAHIN ◽  
YASEMİN DEMIR ◽  
ISMAIL OZMEN
Keyword(s):  
Bacillus Subtilis ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Specific Activity ◽  
Moisture Level ◽  
Protease Production ◽  
Kinetic Properties ◽  
Buffer Solution ◽  
Fermentation Time ◽  
Increased Activity

Objective: In the present work, protease was produced from Bacillus subtilis under solid-state fermentation (SSF). The effect of lyophilization with different additives on the activity of protease in an organic solvent and kineteci properties was investigated. Methods: Production conditions of protease (fermentation time, moisture level, initial pH, temperature) were optimized. After production, it was partially purified and then, lyophilized with different additives from an aqueous buffer solution containing 98% (w/w) of different additives (pumice, KCl, without additive) for 72 h after freezing in liquid nitrogen. After that, the effect of organic solvents (2.5% and 5% of DCM, ethanol, hexane, toluene) on these lyophilized protease preparations was determined and their kinetic properties were determined. Results: Optimum protease production was obtained with 40% of moisture level, at pH 7.5, 37 °C after 24 h fermentation. It was partially purified by using ammonium sulphate precipitation (20-80%) with 5.8-fold and specific activity of 38 U/mg and then dialysed with 6.4-fold and a specific activity of 35 U/mg. Co-lyophilization of protease with pumice and KCl was increased activity of an enzyme in aqueous organic solvents when compared lyophilized protease without additive. Used solvents, except DCM, were increased activity of lyophilized protease with pumice/KCl. It was found that the lyophilization with pumice and KCl resulted in an increasing in the catalytic efficiency, while it was decreased in Km and Vmax values. Conclusion: The obtained findings demonstrated that protease from B. subtilis can effectively be produced under SSF by using wheat bran and used in industrial applications because of showing improved activity in an organic solvent by co-lyophilization with pumice/KCl.

scholarly journals Laccase and Its Mutant Displayed on the Bacillus subtilis Spore Coat for Oxidation of Phenolic Compounds in Organic Solvents

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 606
Author(s):  
Silu Sheng ◽  
Edgardo T. Farinas
Keyword(s):  
Bacillus Subtilis ◽  
Organic Solvents ◽  
Environmental Changes ◽  
Sinapic Acid ◽  
Product Yield ◽  
Spore Coat ◽  
Subtilis Spore ◽  
Bacillus Subtilis Spore ◽  
Cota Laccase ◽  
Inert Surface

Enzymes displayed on the Bacillus subtilis spore coat have several features that are useful for biocatalysis. The enzyme is preimmobilized on an inert surface of the spore coat, which is due to the natural sporulation process. As a result, protein stability can be increased, and they are resistant to environmental changes. Next, they would not lyse under extreme conditions, such as in organic solvents. Furthermore, they can be easily removed from the reaction solution and reused. The laboratory evolved CotA laccase variant T480A-CotA was used to oxidize the following phenolic substrates: (+)-catechin, (−)-epicatechin, and sinapic acid. The kinetic parameters were determined and T480A-CotA had a greater Vmax/Km than wt-CotA for all substrates. The Vmax/Km for T480A-CotA was 4.1, 5.6, and 1.4-fold greater than wt-CotA for (+)-catechin, (−)-epicatechin, and sinapic acid, respectively. The activity of wt-CotA and T480A-CotA was measured at different concentrations from 0–70% in organic solvents (dimethyl sulfoxide, ethanol, methanol, and acetonitrile). The Vmax for T480A-CotA was observed to be greater than the wt-CotA in all organic solvents. Finally, the T480A-CotA was recycled 7 times over a 23-h period and up to 60% activity for (+)-catechin remained. The product yield was up to 3.1-fold greater than the wild-type.

scholarly journals Effects of Organic Solvent on Curing Behavior and Storage Stability for Waterborne Paint Containing Catalyst Encapsulated in Micelles

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 722
Author(s):  
Shuji Yomo
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Storage Stability ◽  
Dibutyltin Dilaurate ◽  
Film Properties ◽  
Surfactant Micelles ◽  
Catalytic Function ◽  
Hydrophilic Lipophilic Balance ◽  
Before And After ◽  
And Storage

In this study, a 2-pack isocyanate curing waterborne paint (without organic solvents) encapsulating dibutyltin dilaurate (hereinafter, DBTL) in nonionic surfactant micelles with an hydrophilic–lipophilic balance of 13–14 in advance releases DBTL when the micelles are collapsed at 80 °C or higher, whereby the curing progresses rapidly. On the other hand, the viscosity levels of the paint before and after being left at 40 °C for 1 h are almost the same. Organic solvents are mandatory for waterborne paints to provide paint and film properties, but they might collapse the micelles when they are formulated in the paint. In this study, we investigate whether the abovementioned paint containing organic solvents can develop switching functionality in terms of maintaining the storage stability at 40 °C and expressing a catalytic function at 80 °C to progress the curing. As a result, we find that if the solubility of the organic solvent in water at 20 °C is at least 10 g/100 mL and the boiling point is ≤200 °C, both curing and storage stability can be achieved.

Effects of organic solvents on immobilized enzyme catalyses. Chymotrypsin immobilized on porous glass

1981 ◽  
Vol 59 (19) ◽  
pp. 2921-2925 ◽  
Author(s):  
J. Bryan Jones ◽  
Diana H. Pliura
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Porous Glass ◽  
Immobilized Enzyme ◽  
Butyl Alcohol ◽  
Solvent Concentration ◽  
Marked Contrast ◽  
Practical Applications ◽  
Tert Butyl Alcohol ◽  
Esterolytic Activity

The esterolytic activity of native chymotrypsin (CT) immobilized on ionically neutral porous glass beads has been studied in the presence of up to 20% (v/v) of the organic solvents methanol, ethanol, 2-propanol, tert-butyl alcohol, dioxane, and DMSO. In marked contrast to the variations observed with native CT, inhibition of CT immobilized on glass (CT–glass) was independent of the nature of the organic solvent. The overall activity, as indicated by kc(app)/km(app), decreased by 35–50% as the concentration of all solvents surveyed was increased up to 20%. In general, high organic solvent concentration accelerated the rate of protein release from the insoluble catalyst. For practical applications in aqueous organic solvents CT–glass conjugates are inferior to those of the enzyme attached to Sephadex.

scholarly journals Diverse resourcing of Nerium indicum leaves for bio-utilization

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1785-1793
Author(s):  
Dongli Ma ◽  
Yuanyuan Chen ◽  
Yong Lai ◽  
Zanpei Zhang ◽  
Ximei Li ◽  
...  
Keyword(s):  
Organic Solvent ◽  
Organic Solvents ◽  
Raw Materials ◽  
Chemical Constituents ◽  
Food Additives ◽  
Ornamental Plant ◽  
Bioactive Ingredients ◽  
Ft Ir ◽  
Medicinal Properties ◽  
Alcohol Benzene

Nerium indicum is an ornamental plant that is widely distributed in tropical and subtropical regions wordwide. It has toxic and medicinal properties which is closely related to the bioactive ingredients contained in Nerium indicum. In our research, the leaves of Nerium indicum was used as raw materials to study the chemical constituents and their effects. The chemical constituents of the leaves were analyzed by FT-IR and GC-MS with alcohol, benzene and acetone as organic solvents. A total of 73 compounds were obtained by acetone organic solvent, 25 compounds were extracted from benzene and 146 compounds were obtained from alcohol. Rich bioactive and bioenergy components were found in all three kinds of extract, suggesting that Nerium indicum leaves are of great significance for the diverse resourcing of bio-utilization including biomedicine, bioenergy, aroma, food additives.

A Microbiological Assay for Penicillic Acid1

1978 ◽  
Vol 41 (6) ◽  
pp. 432-434 ◽  
Author(s):  
F. J. OLIVIGNI ◽  
L. B. BULLERMAN
Keyword(s):  
Bacillus Subtilis ◽  
Biological Activity ◽  
Thin Layer ◽  
Linear Relationship ◽  
Acid Concentration ◽  
Spore Suspension ◽  
Liquid Media ◽  
Penicillic Acid ◽  
Bioassay Method ◽  
Quantitative Bioassay

Six bactertial cultures were studied in a search for an organism sensitive to penicillic acid suitable for use in a quantitative bioassay of this mycotoxin. A vegetative culture and a commercially prepared spore suspension of Bacillus subtilis were both sensitive to as little as 1 μg of penicillic acid and exhibited a linear relationship between 1 and 100 μg. The bioassay method was comparable in accuracy to thin layer chromatographic assay. The procedure was used to verify the biological activity of sample extracts, as well as to quantitate penicillic acid concentration in samples of liquid media and corn. The bioassay is sensitive, rapid (15–17 h), simple and inexpensive.

The wormlike micelles formed using an ionic liquid surfactant and polar organic solvents at low temperature without additives and their lubricant properties

Soft Matter ◽  
2021 ◽  
Author(s):  
Huijiao Cao ◽  
Wenlin Xu ◽  
Xia Guo
Keyword(s):  
Ionic Liquid ◽  
Low Temperature ◽  
Organic Solvent ◽  
Organic Solvents ◽  
Wormlike Micelles ◽  
Polar Organic Solvents ◽  
Ionic Liquid Surfactant ◽  
Nonpolar Organic

Wormlike micelles (or reverse wormlike micelles) are flexible cylindrical chains that are normally formed in water (or a nonpolar organic solvent) at 25.0 °C or above; the formation of wormlike micelles at lower temperatures is rare.

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