scholarly journals Purification and properties of an amine dehydrogenase from Pseudomonas AM1 and its role in growth on methylamine

1968 ◽  
Vol 106 (1) ◽  
pp. 245-255 ◽  
Author(s):  
R R Eady ◽  
P J Large

1. Whole cells of Pseudomonas AM1 grown on methylamine oxidize methylamine, formaldehyde and formate. Crude extracts oxidize methylamine only if supplemented with phenazine methosulphate. 2. By using a spectrophotometric assay, the methylamine-oxidizing enzyme has been purified 20-fold in 31% yield. 3. The enzyme is a dehydrogenase, unable to utilize oxygen, NAD, NADP, flavines or menadione as electron acceptors, but able to utilize phenazine methosulphate, ferricyanide, cytochrome c or brilliant cresyl blue. 4. The enzyme is non-specific, readily oxidizing aliphatic monoamines and diamines, histamine and ethanol-amine. Secondary and tertiary amines, quaternary ammonium salts and aromatic amines are not oxidized. 5. The pH optima for methylamine, n-pentylamine and putrescine are respectively 7·6, 8·0 and 8·5. 6. The Km value for methylamine is 5·2μm and that for phenazine methosulphate 56μm. 7. The enzyme will withstand heating for 15min. at 80° without loss of activity, but is inactivated at higher temperatures. It is not inactivated by any pH value between 2·6 and 10·6. 8. The dehydrogenase is inhibited by semicarbazide (Ki 3·35μm), isoniazid (Ki 1·17μm), cuprizone (Ki 0·49μm), p-chloromercuribenzoate (Ki 0·45mm) and quinacrine (Ki 12·1mm). 9. The enzyme is absent from succinate-grown cells, and, during adaptation from succinate to methylamine, activity appears before growth on methylamine begins.

1925 ◽  
Vol 9 (2) ◽  
pp. 235-253 ◽  
Author(s):  
Marian Irwin

When the living cells of Nitella are placed in a solution of brilliant cresyl blue containing NH4Cl, the rate of accumulation of the dye in the sap is found to be lower than when the cells are placed in a solution of dye containing no NH4Cl and this may occur without any increase in the pH value of the cell sap. This decrease is found to be primarily due to the presence of NH3 in the sap and seems not to exist where NH3 is present only in the external solution at the concentration used.


1927 ◽  
Vol 10 (3) ◽  
pp. 425-436 ◽  
Author(s):  
Marian Irwin

The effect of various substances on living cells may be advantageously studied by exposing them to such substances and observing their subsequent behavior in solutions of a basic dye, brilliant cresyl blue. The rate of penetration of the basic dye, brilliant cresyl blue, is decreased when cells are exposed to salts with monovalent cations before they are placed in the dye solution (made up with borate buffer mixture). This inhibiting effect is assumed to be due to the effect of the salts on the protoplasm. This effect is not readily reversible when cells are transferred to distilled water, but it is removed by salts with bivalent or trivalent cations. In some cases it disappears in dye made up with phosphate buffer mixture, or with borate buffer mixture at the pH value in which the borax predominates, and in the case of NaCl it disappears in dye containing NaCl. No inhibiting effect is seen when cells are exposed to NaCl solution containing MgCl2 before they are placed in the dye solution. The rate of penetration of dye is not decreased when cells are previously exposed to salts with bivalent and trivalent cations. The rate is slightly increased when cells are placed in the dye solution containing a salt with monovalent cation and probably with bivalent or trivalent cations. In the case of the bivalent and trivalent salts the increase is so slight that it may be negligible.


2014 ◽  
Vol 989-994 ◽  
pp. 841-844
Author(s):  
Yi Hua Jiang ◽  
Xin Long Jiang ◽  
Cheng Gang Cai

Orthogonal experiment optimization of adsorption conditions with the factors of pH value, adsorption time, adsorbent amount of brilliant cresyl blue wastewater by brewer's grains were studied. The results showed that optimum adsorption conditions were as follows: 100 mL brilliant cresyl blue dye solution of 150 mg·L-1,adding 5.0 g·L-1brewer's grains of 60~80 mesh and adsorbed for 2.0 h,extraction temperature 30°C,pH 5.0. Under the optimal conditions, the maximal absorption rate got 95.12%.The brewer's grains is a promising, cheap, efficient, new biological materials of adsorption for brilliant cresyl blue in wastewater.


1923 ◽  
Vol 5 (6) ◽  
pp. 727-740 ◽  
Author(s):  
Marian Irwin

When cells of Nitella are placed in buffer solutions at pH 9, there is a very slow and gradual increase in the pH of the sap from pH 5.6 to 6.4 (when death of the cells takes place). If the living cells are placed in 0.002 per cent dye solutions of brilliant cresyl blue at different pH values (from pH 6.6 to pH 9), it is found that the rate of penetration of the dye, and the final equilibrium attained, increases with increase in pH value, which can be attributed to an increase in the active protein (or other amphoteric electrolyte) in the cell which can combine with the dye.


1926 ◽  
Vol 10 (1) ◽  
pp. 75-102 ◽  
Author(s):  
Marian Irwin

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene. The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases. The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH3.


2008 ◽  
Vol 10 (2) ◽  
pp. 181-184 ◽  
Author(s):  
Ryohei Yamaguchi ◽  
Shoko Kawagoe ◽  
Chiho Asai ◽  
Ken-ichi Fujita

2003 ◽  
Vol 43 (2) ◽  
pp. 179-187 ◽  
Author(s):  
Elisabeth Rodríguez-González ◽  
Manel López-Bejar ◽  
Dolors Izquierdo ◽  
María-Teresa Paramio

Author(s):  
Danail Georgiev ◽  
Georgi Dobrev ◽  
Stefan Shilev

Aim: To characterize the enzyme phytase produced by phytase-active Candida melibiosica 2491 for subsecuent use in feed industry. Methods: C. melibiosica 2491 had been selected among 118 strains as the most productive strain of phytase. In present study, the enzyme was first purified through electrophoresis grade in four steps: precipitation with organic solvent, ultrafiltration, gel chromatography and Denaturing gel electrophoresis (SDS–PAGE). Results: Higher levels of purification were obtained using ethanol. The gel chromatography showed an elution maximum at 11-12 fractions that characterize the corresponding one as high-molecular weight phytase. The purification level was found to be 19.5 folds with specific enzyme activity of 2.75 U/mg protein and yield – 19.64 %. Furthermore, the molecular weight of purified phytase was estimated to 35.9 кDa, with optimum of pH – at 4.5 and optimum of temperature at 55 °C. Maximum phytase activity in case of whole cells was found at 50 оС, which was less than using the purified enzyme. It was activated through 5 mM of Ba2+, 10 mM of Mn2+ and K+ ions. Total inhibition effect was achieved from Fe3+, Hg2+ and Zn2+. Copper ions (Cu2+) in concentrations at 5 mM conducted to partial inhibition effect, but at 10 mM the phytase activity was equal to zero. Low inhibition effect was determined in case of cobalt ions (Co2+) at concentrations of 10 mM. The phytase displayed broad sub­strate specificity and the Km for phytate was estimated to be 0.21 mM under the experimental conditions, while Vmax – 19.9 µМ/ml. Conclusion: Although the phytase produced by C. melibiosica 2491 is a promising enzyme to be used successfully in feed production, more investigations are needed to ensure its advantages.


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