Adoptive alterations in the fermentative sequence of Lactobacillus casei

Naik, V.R.; Nadkarni, G. B.

doi:10.1016/0003-9861(68)90163-x

Cited by 14 publications

(3 citation statements)

References 39 publications

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“…Grown as reported [20], L. casei cells were harvested after 18 hr, sonicated, centrifuged, and submitted to i) ammonium sulphate fractionation, ii) Sephadex-Blue-F3GA chromatography, and iii) Sepharose-Oxamate chromatography, for which the affinity matrices were prepared as reported [21], [22]. The LDH-enriched ammonium-sulfate fraction was applied in phosphate buffer (50 mM, pH 7.0) to Sephadex-Blue column pre-equilibrated with phosphate buffer (20 mM, pH 7.0) at 4°C.…”

Section: Methodsmentioning

confidence: 98%

Redox Specificity of 2-Hydroxyacid-Coupled NAD+/NADH Dehydrogenases: A Study Exploiting “Reactive” Arginine as a Reporter of Protein Electrostatics

2013

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With “reactive” arginine as a kinetic reporter, 2-hydroxyacid dehydrogenases are assessed in basis of their specialization as NAD+-reducing or NADH-oxidizing enzymes. Specifically, M4 and H4 lactate dehydrogenases (LDHs) and cytoplasmic and mitochondrial malate dehydrogenases (MDHs) are compared to assess if their coenzyme specificity may involve electrostatics of cationic or neutral nicotinamide structure as the basis. The enzymes from diverse eukaryote and prokaryote sources thus are assessed in “reactivity” of functionally-critical arginine as a function of salt concentration and pH. Electrostatic calculations were performed on “reactive” arginines and found good correspondence with experiment. The reductive and oxidative LDHs and MDHs are assessed in their count over ionizable residues and in placement details of the residues in their structures as proteins. The variants found to be high or low in ΔpKa of “reactive” arginine are found to be also strong or weak cations that preferentially oxidize NADH (neutral nicotinamide structure) or reduce NAD+ (cationic nicotinamide structure). The ionized groups of protein structure may thus be important to redox specificity of the enzyme on basis of electrostatic preference for the oxidized (cationic nicotinamide) or reduced (neutral nicotinamide) coenzyme. Detailed comparisons of isozymes establish that the residues contributing in their redox specificity are scrambled in structure of the reductive enzyme.

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Section: Methodsmentioning

confidence: 98%

Redox Specificity of 2-Hydroxyacid-Coupled NAD+/NADH Dehydrogenases: A Study Exploiting “Reactive” Arginine as a Reporter of Protein Electrostatics

2013

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“…Dehydrogenases of this pathway have been shown to be present in a number of strains of homofermentative lactic acid bacteria (Buyze et al, 1957) although the presented investigations failed to demonstrate these enzymes in anaerobically grown cultures. However, Naik and Nadkarni (1968) adapted strain 7469 to grow on pentoses and obtained an approximately 44-fold increase of glucose 6-phosphate dehydrogenase with a concomitant reduction of FDP aldolase by 27-fold. A similar correlation to this was found in the presented investigations as aeration increased glucose 6-phosphate and 6-phosphogluconate dehydrogenase activity while at the same time lead to a reduction of FDP aldolase activity.…”

Section: Discussionmentioning

confidence: 98%

“…As strains of L. casei use predominantly a glycolytic pathway (Gibbs et al, 1950) but also possess typical hexose monophosphate pathway enzymes (Buyze, van den Hamer and de Haan, 1957), this may suggest that under different environmental conditions changes could occur similar to the adaptive alterations of the metabolic constitution of cells if grown on pentoses (Naik and Nadkarni, 1968). On the other hand, de Vries et al (1970) have reported that under both aerobic and anaerobic conditions 80 ~ of the glucose can be recovered as lactic acid.…”

Section: Introductionmentioning

confidence: 97%

The effect of oxygen and pH on the glucose metabolism ofLactobacillus casei var.rhamnosus ATCC 7469

Manderson

Doelle

1972

Antonie van Leeuwenhoek

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Growth of cultures of Lactobacilhls casei ATCC 7469 without pH control under aerobic conditions resulted in very low maximum specific growth rates (0.19 hr-~), exponential glucose utilization rates (0.10 log units/hr/ml of culture) and exponential lactate production rates (0.17 log units/hr/ml of culture), compared to anaerobic cultures. In anaerobic cultures glucose was converted stoichiometrically to lactate but in aerobic cultures this was never observed. It was found that aeration affects both the rate at which glucose is converted to lactate and the stoichiometry of this conversion. The investigation of a number of glucose-metabolizing enzymes suggests that an oxidative pathway for glucose breakdown becomes operative under aerated conditions.

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