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Several incorrect statements by Carr and Shimwell (1961) and Hodgkiss, Shimwell and Carr (1962) on the classification of acetic acid bacteria are pointed out and briefly discussed.

Although crystalline 6-deoxy-L-idose (2) and crystalline 6-deoxy-L-sorbose (3) have similar melting points and specific rotations, they can be conclusively differentiated from one another through paper chromatography and paper electrophoresis. 6-Deoxy-L-idose cannot be converted into 6-deoxy-L-sorbose on short heating in very dilute aequeous mineral acids. The synthesis of amorphous 6-deoxy-L-psicose (17), through oxidative fermentation of 6-deoxy-L-allitol with Acetobacter suboxydans, has been described.

Cell-free extracts of Acetobacter suboxydans were prepared which were capable of condensing α-ketoisovalerate with 14 C-labeled acetyl-coenzyme A to yield 14 C-labeled α-isopropylmalate. The product of the reaction was isolated by paper and column chromatography and was characterized by recrystallization with synthetic α-isopropylmalic acid to constant specific radioactivity. The formation of α-isopropylmalate by extracts of A. suboxydans plus the ability of the organism to grow in a simple glucose-glycerol medium containing glutamic acid as the only amino acid indicate that the pathway for leucine biosynthesis shown to exist in yeast and Salmonella typhimurium also occurs in A. suboxydans . As a comparison, the condensation of oxalacetate and ( 14 C) acetyl-coenzyme A to yield ( 14 C) citric acid was shown, by similar means, to occur in A. suboxydans . This is of interest since the existence of this classical condensing enzyme has hitherto not been demonstrated in this organism. This reaction was further demonstrated in cell-free extracts of A. suboxydans by means of a spectrophotometric assay at 232 mμ which measured the cleavage of the carbon-sulfur bond of acetyl-coenzyme A in the presence of oxalacetate. Comparison of the specific activities of crude cell-free extracts indicated a much more extensive occurrence of this reaction in yeast than in A. suboxydans .

In addition to the main product l -erythrulose, altro -heptulose and l -threitol were found in medium in which meso -erythritol was undergoing oxidation by Acetobacter suboxydans . These compounds were isolated by paper chromatography and identified by their dibenzylidene derivatives. It was established that threitol had the l -configuration by measuring the optical rotation. Another compound present in the medium appeared to be heptulose phosphate by its chromatographic behavior. The formation of altro -heptulose was not detected when sorbitol ( d -glucitol), ribitol (adonitol), d -mannitol, d -ribose, or l -erythrulose were used as substrates. No heptulose formation was observed when meso -erythritol was oxidized by Acetobacter xylinium . C 14 studies revealed that the three compounds detected in the medium were derived from meso -erythritol. Some possible biochemical pathways by which these compounds might be synthesized are discussed. To the authors' knowledge this is the first report of the synthesis in vivo of this heptulose and of l -threitol by Acetobacter suboxydans .

Dihydroxyacetone was quantitatively produced from glycerol during the primary exponential growth phase and depleted during the secondary exponential phase. Although no growth was detected on the basal medium, growth occurred upon addition of dihydroxyacetone.

d-Glucosaminic acid has recently been found to be an oxidized product of d-glucosamine formed by Ps. fluorescens. It has been revealed that many strains of oxidative bacteria can oxidize glucosamine. The formation of glucosamine acid has been recognized among a large number of strains of Pseudomonas, Acetobacter and Gluconobacter, by means of paper chromatography. Furthermore, one of these strains, A. melanogenum Beijerinck, oxidized glucosamine to glucosaminic acid with the theoretical consumption of oxygen as Ps. fluorescens liquefaciens. Glucosaminic acid was proved by isolation and identification by means of using resting cells.The experiment of growth shows that Ps. fluorescens liq. could not secure any energy by means of the oxidation of glucosamine.

D-Glucosaminic acid has recently been found to be an oxidized product of D-glucosamine formed by Ps. fluorescens. It has been revealed that many strains of oxidative bacteria can oxidize glucosamine. The formation of glucosaminic acid has been recognized among a large number of strains of Pseudomonas, Acetobacter and Gluconobacter, by means of paper chromatography. Furthermore, one of these strains, A. melanogenum Beijerinck, oxidized glucosamine to glucosaminic acid with the theoretical consumption of oxygen as Ps. fluorescens liquefaciens. Glucosaminic acid was proved by isolation and identification by means of using resting cells. The experiment of growth shows that Ps. fluorescens liq. could not secure any energy by means of the oxidation of glucosamine.

A way of predicting the conditions of product formation in a two-state continuous cultivation on the basis of analyzing the batch process is described. The prediction applies to processes where the product formation is proportional to the growth rate and where the relationship between culture activity and the external conditions is linear. Using the example of glucose oxidase production byAspergillus niger the prediction is borne out. The difference between the predicted and found values does not exceed 15%.

SUMMARY: Comparisons are given of the output of sorbose from 3 litre cultures of Acetobacter suboxydans grown in a sorbitol medium in batch and continuous culture. An estimate is given of the investment value of a continuous process of sorbose production relative to the batch process.

1. Growing cells of a small number of strains of Acetomonas oxydans oxidized d-quinate to 5-dehydroquinate. 2. d-Shikimate was oxidized to 4,5-dihydroxy-3-oxocyclohex-1-ene-1-carboxylate (3-dehydroshikimate, formerly 5-dehydroshikimate). 3. d-Dihydroshikimate was oxidized to the corresponding 5-dehydro compound, but epidihydroshikimate oxidation by growing cells was not observed. 4. Cell-free extracts oxidized d-quinate to 5-dehydroquinate with the consumption of the stoicheiometric amount of oxygen, but oxidation of shikimate and dihydroshikimate did not go to completion. 5. Oxidation of quinate was brought about by a constitutive particulate enzyme probably localized in the cytoplasmic membrane. No evidence was found for the participation of NAD, NADP or free flavine compounds in electron transport, but the system was cytochrome-linked.

Acetobacter suboxydans does not contain an active tricarboxylic acid cycle, yet two pathways have been suggested for glutamate synthesis from acetate catalyzed by cell extracts: a partial tricarboxylic acid cycle following an initial condensation of oxalacetate and acetyl coenzyme A. and the citramalate-mesaconate pathway following an initial condensation of pyruvate and acetyl coenzyme A. To determine which pathway functions in growing cells, acetate- 1 - 14 C was added to a culture growing in minimal medium. After growth had ceased, cells were recovered and fractionated. Radioactive glutamate was isolated from the cellular protein fraction, and the position of the radioactive label was determined. Decarboxylation of the C5 carbon removed 100% of the radioactivity found in the purified glutamate fraction. These experiments establish that growing cells synthesize glutamate via a partial tricarboxylic acid cycle. Aspartate isolated from these hydrolysates was not radioactive, thus providing further evidence for the lack of a complete tricarboxylic acid cycle. When cell extracts were analyzed, activity of all tricarboxylic acid cycle enzymes, except succinate dehydrogenase, was demonstrated.

Synthesis of the only unknown deoxyfructose, 4-deoxy-D-threohexulose, is reported. Its preparation involved reductive lithium aluminum hydride ring opening of 3,4-anhydro-1,2:5,6-di-O-isopropylidene- D-talitol, followed by hydrolysis of the resulting epimeric deoxy diisopropylidene hexitols and selective Acetobacter suboxydans oxidation of 3-deoxy-D-arabinohexitol. Kinetic studies using 4-deoxy-D-threohexulose as substrate for yeast hexokinase support the premise that the C-4 hydroxyl is a binding group in formation of the enzyme–substrate complex. Enzymatic synthesis of 4-deoxy-D-threohexulose 6-phosphate and 4-deoxy-D-threohexulose 1,6-diphosphate has been achieved in low yield from 4-deoxy-D-threohexulose.

A gas-liquid chromatographic method, based on acetylation of polyols, was applied to a study of polyols in urine and in serum. The profile of the normal urinary polyol excretion was described and the formation of additional polyols was demonstrated by treating samples with sodium borohydride prior to chromatography. In diabetes mellitus the urinary excretion of mannitol and myo-inositol was elevated. In cases of chronic renal failure the retention of polyols in serum was demonstrated and the level of myo-inositol was shown to be increased both in serum and in urine. The design of the experimental conditions eliminated the errors due to the intake of exogenous polyols. The metabolic significance of the findings is still to be determined.

Путем продления нормальной ферментации сорбозы была приготовлена смесь, содержащая 5-кето-сорбозу, возникающую путем дальнейшей дегидрогенации сорбозы. Из этой смеси с помощью разделения на колонке катекса в форме Ba2+ была выделена кристаллическая 5-кето-сорбоза. Так были подтверждены выводы предыдущего сообщения относительно этого побочного метаболита ферментации сорбозы.

Acetobacter suboxydans is an obligate aerobe for which an operative tricarboxylic acid cycle has not been demonstrated. Glutamate synthesis has been reported to occur by mechanisms other than those utilizing isocitrate dehydrogenase, a tricarboxylic acid cycle enzyme not previously detected in this organism. We have recovered α-ketoglutarate and glutamate from a system containing citrate, nicotinamide adenine dinucleotide (NAD), a divalent cation, pyridoxal phosphate, an amino donor, and dialyzed, cell-free extract. Aconitase activity was readily detected in these extracts, but isocitrate dehydrogenase activity, measured by NAD reduction, was masked by a cyanide-resistant, particulate, reduced NAD oxidase. Isocitrate dehydrogenase activity could be demonstrated after centrifuging the extracts at 150,000 × g for 3 hr and treating the supernatant fluid with 2-heptyl-4-hydroxyquinoline N -oxide. It is concluded that A. suboxydans can utilize the conventional tricarboxylic acid cycle enzymes to convert citrate to α-ketoglutarate which can then undergo a transamination to glutamate.

Dialyzed extracts of Acetobacter suboxydans ATCC 621 catalyze 14 CO 2 assimilation in the presence of phosphoenolpyruvate and a divalent cation. The formation of 14 C-oxalacetate was demonstrated and found not to be dependent upon the presence of orthophosphate or diphosphonucleotides. Oxalacetate synthesis was stimulated by orthophosphate and inhibited by aspartate. All attempts to demonstrate a reversible carboxylation mechanism have failed. 14 C-aspartate was synthesized when phosphoenolpyruvate, H 14 Co 3 − , pyridoxal phosphate, and glutamate were added to dialyzed extracts. Chromatographic and spectrophotometric analyses and chemical degradation further demonstrate the presence of a reversible aspartate aminotransferase. The function of oxalacetate synthesis in a bacterium that reportedly lacks an operative tricarboxylic acid cycle is discussed.

In order to know the kinds and forms of vitamin B 12 coenzymes which participate in the formation of glutamic acid through the pathway via citramalate, mesaconate and β-methyla spartate by Acetobacter suboxydans , isolation and identification of the compounds from the bacteria were attempted. From 500 l fermentation of A. suboxydans , 1.7 kg of the freeze-dried cells were obtained. Corrinoids were extracted from the cells with 80% ethanol with or without cyanide, purified with p -chlorophenol-chloroform, fractionated by aluminacolumn chromatography and crystallized in acetone. The paper-ionophoretic, paper-chromatographic, spectrophotometric and microbiological investigations of the cyanocorrinoid showed that the compound obtained might be 5,6-dimethylbenzimidazolyl cobamide. The investigation on the nucleoside, a Ce(III)-decomposition product of the corrinoid proved to be α-ribazole and therefore gave an additional evidence for 5,6-dimethylbenzimidazolyl cobamide. For coenzyme forms, cautions were taken to operate in every process without cyanide and in the dark. Similar physicochemical tests indicated that the coenzyme form of the compound is cobalamin coenzyme.

Since the establishment of p-aminobenzoic acid as a member of the B vitamin group, a considerable interest has been shown in methods of determination in natural materials. Since known chemical methods are not sufficiently sensitive, it became evident that microbiological tests should be the most practicable. The organism Clostridium acetobutylicum has been used (1) but no general assay procedure has been presented. Several bacterial strains which respond to p-aminobenzoic acid have been investigated in this laboratory, but satisfactory assay procedures with these organisms have not yet been devised. For the discovery of the test organism used in the procedure described in this paper, we are indebted to Dr. Beadle and Dr. Tatum who kindly furnished us with a culture of their p-aminobenzoic acid requiring a mutant strain of Neurospora crassa, designated by them as Neurospora crassa p-aminobenzoicless No. 1633 (2). This mold will grow optimally on a medium consisting of inorganic salts, ammonium tartrate, sucrose, biotin, and p-aminobenzoic acid. For purposes of assay, however, it has proved advantageous to supplement this basal medium with natural extracts which are either naturally low in p-aminobenzoic acid or have been treated to remove it. With such a complex medium, the possibility of interference by toxic substances or stimulatory substances other than p-aminobenzoic acid which might be present in samples to be assayed is reduced to a minimum. Since the completion of a considerable part of the experimental work described in this paper, microbiological assay methods for p-aminobenzoic acid have been published by Landy and Dicken (3) utilizing the organism Acetobacter suboxydans and by Lewis (4) using Lactobacillus arabinosus 17-5.

Two easy and quick assays are described for the semiquantitative determination of soluble and particulate dehydrogenases in bacteria. Soluble NAD- and NADP-linked dehydrogenases are determined by a spot test on paper. The presence of a dehydrogenase is recognized by the fluorescence of the reduced cofactor on the paper. Particle-linked dehydrogenases are detected by the bleaching of 2,6-dichlorophenol-indophenol. The advantages of these assays are that they are reliable, inexpensive to perform and require a minimum of time, labour and enzyme material. This may be useful as a comparative biochemical tool for bacterial taxonomy.

Previous papers from this laboratory (King and Cheldelin, 1952, 1952a, 1954; Hauge et al., 1955, 1955a) have reported on the oxidation of carbohydrates in Acetobacter suboxydans. Neither resting nor disintegrated cells can oxidize acetate or other intermediates of the tricarboxylic acid cycle. These findings have recently been confirmed in another laboratory (Rao and Gunsalus, 1955). From the comparative biochemical viewpoint, it is of interest to study the oxidative behavior of other species of the genus Acetobacter. Results reported in this paper demonstrate that Acetobacter pasteurianum, in contrast to A. suboxydans, can oxidize all the intermediates of the Krebs cycle. Other evidence also indicates the functioning of this cycle in A. pasteurianum.

WE have cultivated Acetobacter acetigenum N.C.I.B. 8132, a cellulose-forming micro-organism, in 10 litres of medium in 40 ‘Glaxo’ flasks, which were shaken during incubation at 30° for twenty-one days. The medium contained (gm./l.): potassium dihydrogen phosphate, 2.0; crystalline magnesium sulphate, 1.0; crystalline ferrous sulphate, 0.01; ammonium hydrogen phosphate, 2.5; calcium D-pantothenate, 0.002 ; riboflavin, 0.002; biotin, 0.0001; glycerol, 30; lactic acid, 10.2; the pH value was adjusted with potassium hydroxide to 4.6. The metabolism solution was Seitz-filtered to remove cells and cellulose and concentrated to 500 ml. over barium carbonate, in vacuo at 35°. Activated charcoal, ‘Ultrasorb S.C. 120/240’ (British Carbo Norit Union) as used by Hughes and Whelan1, was sieved through a British Standards 170 mesh and the material retained on the sieve was used to pack two ‘Pyrex’ glass columns (138 × 7.8 cm.) to a depth of 105 cm. In each column 1.9 kgm. of this charcoal rested on a pad of glass-wool overlayed with 100 gm. of ‘Celite’ added as a slurry in water. The columns were washed each with 5 litres of 50 per cent (v/v) aqueous ethanol and then each with 20 litres of distilled water. After removal of insoluble barium salts the metabolism concentrate was rediluted to 10 litres with distilled water and passed through the columns during 14 hr. Each column was eluted with 80 litres of distilled water followed by aqueous ethanol solutions (each of 50 litres) in which the respective ethanol percentages (v/v) were 0.5, 5, 10, 20, 35, and 50. Six aqueous ethanolic fractions, A 1–A 6, were collected and concentrated at 35°. Portions of each were de-ionized with ‘Zeo-Karb 225’ and ‘Deacidite E’ and chromatographed on paper against authentic sugars using (a) n-propanol/water/ethylacetate, 7:2:1 by volume; (b) pyridine/water/ethylacetate, 1:2:2 by volume; (c) ethyl acetate/acetic acid/water, 3:1:3 by volume. The chromatograms gave evidence of the presence of the following sugars: A 2, glucose, fructose, xylose, and ribulose; A 3 similar to A 2 together with a trace of cellobiose; A 4, mainly cellobiose ; A 5, cellotriose and cellotetraose. Fraction A 3 was then de-ionized and submitted to column partition chromatography according to the procedure of Lemieux, Bishop and Pelletier2, which involves the use of ‘Celite No. 535’ to hold the stationary phase. After irrigation with water-saturated n-butanol, the column was extruded and cut into zones as determined by an alkaline permanganate spray. A fraction was separated which, after several further passages through the ‘Celite’ and a final purification by band paper chromatography, yielded 45 mgm. of a substance which had the mobility of glucose when chromatographed in two different solvent systems. An acetate was prepared by heating with anhydrous sodium acetate and acetic anhydride, and after purification this had m.p. 131°, alone or mixed with authentic β-penta-acetyl glucose of m.p. 131°. The infra-red spectra of both acetates were compared and no significant differences could be observed. (Found: C, 49.3; H, 5.8 per cent. Calc. for C16H22O11: C, 49.2; H, 5.7 per cent.)

Kerwar, Suresh S. (Oregon State University, Corvallis), Vernon, H. Cheldelin, and L. W. Parks . Valine-isoleucine metabolism in Acetobacter suboxydans and the inhibition of growth by valine. J. Bacteriol. 88: 179–186. 1964.—Extracts of Acetobacter suboxydans can synthesize valine and isoleucine via acetolactate and acetohydroxybutyrate, respectively. The amounts of these amino acids synthesized from different intermediates were determined. The pathways appear to be identical to those described for yeast, Neurospora , and Escherichia coli . When exogenous valine was added to a synthetic growth medium inoculated with A. suboxydans , no growth of the culture was observed. The inhibitory effect of valine was reversed by the addition of isoleucine. The site and mechanism of valine inhibition were investigated. Threonine deaminase was inhibited by valine and isoleucine but not by leucine. Repression of the deaminase by isoleucine but not by valine was indicated. The data reported in this paper suggest that valine prevented growth of the organism through false feedback inhibition of threonine deaminase, thereby limiting isoleucine biosynthesis.

1. The unknown substance reported in the previous paper was identified as glucosone. The formation of glucosone from fructose by Gluconoacetobacter roseus is a similar reaction with the formation of reductone (enol form of glycerosone) from dihydroxyacetone by the same bacterium. A presumable pathway of ketose oxidation would be shown as follows:2. The fructose dehydrogenase of G. roseus was investigated by Thunberg method. The activity of this dehydrogenase was the same order as that of gluconic acid dehydrogenase and was inhibited by the addition of 1:5.000mol. of 2, 4-dinitrophenol, when other dehydrogenases such as glucose, gluconic acid, and mannitol dehydrogenase were not affected. The fructose dehydrogenase of this bacterium seemed to be of the same type as the dihydroxyacetone dehydrogenase of Acetobacter suboxydans.3. The author isolated a new substance from the fermented broth of fructose. The chemical structure of this compound is now under further investigation. This compound developes purple color with ferric chloride solution and gives different m.p. and Rf value from those of kojic acid, comenic acid, and rubiginol.4. Although the biological induction of kojic acid from glucosone is not yet attained, the author assumes that glucosone would be the most possible intermediate of kojic acid formation, because Bond, Knight and Walker proved in 1937 the existance of the same substance in the brothh fermented by Aspergillus cryzae.

1. The unknown substance reported in the previous paper was identified ad glucosone. The formation of glucosone from fructose by Gluoonoacetobacter roseus is a similar reaction with the formation of reductone (enol form of glycerosone) from dihydroxyacetone by the same bacteria. A presumable pathway of ketose oxidation would be shown as follows: CH2OH CO CHOH R_??_CHOH COH CHOH R -2H→CHO CO CHOH R_??_CHO COH COH R This hypothesis extremely agreed with the experimental data of MAGSANIK and CHARGAFF who had reported the formation of α, β-diketo-inositol from inosose by Acetobacter suboxydans. 2. The fructose dehydrogenase of G. roseus was investigated by ZUNEERG method. The activity of this dehydrogenase was the same order as that of gluconic acid dehydrogenase and was inhibited by the addition of 1:5000 mol. of 2, 4-dinitrophenol, when the other dehydroge-nases such as glucose, gluconic acid, mannitol dehydrogenase did not be affected. The fruc-tose dehydrogenase of this bacteria seemed to be the same type as the dihydroxyacetone dehy-drogenase of Acetobacter suboxydans. 3. The author isolated a new substance from the fermented broth of fructose. The chemi-cal structure of this compound is now under the further investigation. This compound deve-loped purple colour with, ferric chloride solution and gives different m. p. and RF value from those of kojic acid, comenic acid and rubiginol. 4. Although the biological induction of kojic acid from glucosone is not yet attained, the author thinks glucosone would be the most possible intermediate of kojic acid formation, be-cause, in 1937, BOND, KNIGHT and WALKER have proved the existance of same substance in the broth fermented by Aspergillus oryzae.

In extension of the studies on the formation of cellulose by Acetobacter acetigenum (Z-4), the action of this organism on glycerol has now been investigated; this paper records the examination of the products formed in a defined glycerol medium buffered with lactate. Preliminary observations on the action of this organism on ethylene glycol and on inositol are also reported.

2,5-Diketogluconic acid decarboxylase has been purified from extracts of Acetobacter melanogenum. This paper reports the method of purification, the properties of the purified enzyme, and some properties of the reaction product. A crystalline o-nitrophenylhydrazone derivative of the decarboxylation product has been obtained.

When Acetobacter aceti, Acetobacter rancens, Acetobacter acidum-mucosum and Acetobacter acetosum var. nairobiense were grown in defined media containing glucose as sole source of carbon, gentiobiose (O-β- d -glucopyranosyl-(1 → 6)- d -glucopyranose) and sophorose (O-β- d -glucopyranosyl-(1 → 2)- d -glucopyranose) were the principal oligosaccharide products in all cases. These were accompanied by other disaccharides and by higher saccharides. Paper chromatograms showed that each Acetobacter species synthesized the same series of sugars.

GUDDING, ROAR: The suitability of some media and peptones for sulfonamide testing. Acta vet. scand. 1974, 15, 366–380. — The content of p-aminobenzoic acid and folic acid has been determined in some media and peptones, and the sensitivity of Bacillus megaterium, cultivated on these substrates, towards sulfonamides has been examined. The concentrations of p-aminobenzoic acid and folic acid should be as low as possible in suitable substrates, but other factors are also of importance. The presence of antagonists towards folic acid has been demonstrated in some media, and the consequences of these inhibitors are discussed. Three of the media (Paper Disc Method-Antibiotic Sensitivity Medium, AB Biodisk; Sulphonamide Antagonist Free Medium, Mast Laboratories; and Mueller Hinton, Difco Laboratories) seem to be satisfactory for the determination of the resistance of bacteria towards sulfonamides. The application of Acetobacter medium is suggested for the detection of rest concentrations of sulfonamides in foodstuffs. detection of sulfonamide residues; p-aminobenzoic acid; folic acid.

1. The bacterium Acetobacter xylinum produces extracellular cellulose microfibrils that form a pellicle in the medium enmeshing the bacterial cells. These microfibrils may show some localized alignment, which can be seen as birefringence when the culture is viewed between crossed Polaroid sheets. 2. An increase in birefringence can be induced by the addition of small amounts of certain classes of lipids, particularly sterols, to the cultures. 3. A crude lipid extract from Acetobacter cells induced greatly increased birefringence when added to fresh cultures of this organism. 4. When the bacterial lipids were fractionated, most of the activity was recovered in a complex, polar lipid. The lipid is secreted into the medium during growth and is unstable. The non-saponifiable portion of this lipid is shown to be a 1:1 mixture of a saturated and a monounsaturated C35 tetrahydroxy terpene with a hopane ring system in the accompanying paper by Förster et al. (1973). The saturated molecule is referred to as tetrahydroxybacteriohopane. 5. Tetrahydroxybacteriohopane is itself capable of inducing birefringence in cultures as is 22-hydroxyhopane, which was also isolated from the non-saponifiable fraction of the total lipids. 6. The mechanism of induction of birefringence (orientation of microfibrils) is not known. This is unlikely to be a specific effect, since all the above compounds are active (intact lipid, tetrahydroxybacteriohopane, 22-hydroxyhopane), as are other classes of lipid. It is suggested, however, that a common mechanism may be involved and that similar compounds may be concerned with control of microfibril alignment in the cells of higher plants.

SUMMARY: A new type of Aeetobacter, provisionally named Acetobacter acidophilum, has been isolated in pure culture from an experimental vinegar generator originally inoculated with active industrial beechwood shavings. In contrast to other bacteria, this organism needs an acidic medium for growth and has a very specific oxidizing capacity. It does not grow above pH 4·3 and oxidizes only primary alcohols. Other substrates, including glucose and acetic acid, are not oxidized at a rate higher than 1 % of the oxidation rate for ethanol. The new isolation procedure, which has been applied for the strain described in this paper, allows the isolation of the bacteria present on active shavings, suggesting that this type of bacteria belongs probably to the group of organisms responsible for the acetification in the ‘quick vinegar process’.