A polysaccharide produced by a mucoid strain of Moraxella nonliquefaciens with a 2-acetamido-2-deoxy-5-O-(3-deoxy-beta-D-manno-octulopyranosyl)-beta-D- galactopyranosyl repeating unit

A capsular polysaccharide, isolated from the mucoid Moraxella nonliquefaciens strain 3828/60, has been investigated by component analyses, periodate oxidation, methylation analyses, mass spectrometry, 1H and 13C NMR spectroscopy, and hydrolysis to give a disaccharide that was isolated and characterised. The results showed that the polysaccharide has the repeating unit-->3)-beta-D- GalpNAc-(1-->5)-beta-Kdo p-(2-->, with approximately 40% of O-8 of Kdo being acetylated.

Bacterial metabolism of 5-aminosalicylic acid. Initial ring cleavage

The metabolism of 5-aminosalicylate (5AS) by a bacterial strain, Pseudomonas sp. BN9, was studied. Intact cells of Pseudomonas sp. BN9 grown with 5AS oxidized 5AS and 2,5-dihydroxybenzoate (gentisate), whereas cells grown with gentisate oxidized only the growth substrate of all substituted salicylates tested. Cell extracts from Pseudomonas sp. BN9 catalysed the stoichiometric reaction of 1 mol of oxygen with 1 mol of 5AS to a metabolite with an intense u.v.-absorption maximum at 352 nm (pH 8.0). This metabolite was accumulated under neutral conditions, but was rapidly destroyed at acid pH. It was identified by m.s. and acid-catalysed deamination to fumarylpyruvate (trans-2,4-dioxohept-5-enedioic acid) as cis-4-amino-6-carboxy-2-oxohexa-3,5-dienoate, thus demonstrating direct cleavage of the monohydroxylated substrate 5AS to a non-aromatic ring-fission product. The enzyme responsible for conversion of 5AS was shown to be Fe(II)-dependent and to be distinct from gentisate 1,2-dioxygenase in strain BN9.

Propachlor degradation by a soil bacterial community

Soil from a pesticide disposal site was used to enrich for microorganisms that degraded the acylanilide herbicide propachlor (2-chloro-N-isopropylacetanilide). After seven transfers of the enrichment, the culture contained about six strains. The highest yield of microbial biomass occurred if just two of these isolates, strains DAK3 and MAB2, were inoculated into a mineral salts medium containing propachlor. When only strain DAK3 was grown on propachlor, a metabolite (2-chloro-N-isopropylacetamide) was released into the medium. Strain MAB2 could grow on this metabolite. The results of morphological and physiological tests suggest that strains DAK3 and MAB2 most closely resemble species belonging to the genera Moraxella and Xanthobacter, respectively. Strain DAK3 can respire and grow on N-substituted acylanilides containing methyl, ethyl, or isopropyl substitutions, but is incapable of respiration or growth on acetanilide, aniline, or the acylanilide herbicides alachlor and metolachlor. Strain DAK3 appears to use the aromatic C atoms of propachlor for growth, as suggested by the growth yield on propachlor and the induction of catechol 2,3-oxygenase activity in acylanilide-grown cells.

Preliminary study on relationships among strains forming a bacterial community selected on naphthalene from a marine sediment

Two bacterial strains were isolated from a bacterial community formed of nine strains, selected from a marine sediment on a seawater medium with naphthalene as sole carbon source. The two strains studied in the present work were the only strains of this community able to grow in pure culture on naphthalene; therefore, they were called "primary" strains. The seven other strains were maintained in the community by using metabolic intermediates of the two primary strains; they were called "auxiliary" strains. Regulation of naphthalene metabolism was studied for the two primary strains. They oxidized naphthalene into catechol, which was degraded only by the meta pathway. For Pseudomonas Lav. 4, naphthalene oxygenase and salicylate hydroxylase were inducible; catechol 2,3-dioxygenase was constitutive. For Moraxella Lav. 7, naphthalene oxygenase was constitutive; salicylate hydroxylase and catechol 2,3-oxygenase were inducible. The Moraxella strain carries two cryptic plasmids, about 63- and 85-kb in molecular size. In the bacterial community culture medium, Moraxella Lav. 7 prevented accumulation of 2-hydroxymuconate semialdehyde formed by Pseudomonas Lav. 4. The auxiliary strains take up formic, acetic, pyruvic, propionic, and succinic acids released by the two primary strains.

Comparative characterization of the leukocidic and hemolytic activity of Moraxella bovis

The cytotoxic effect of Moraxella bovis 118F on bovine neutrophils was evaluated and characterized by use of a 51Cr release assay. Neutrophils harvested from healthy adult cattle were labeled with 51Cr. The leukocidic activity produced by M bovis 118F, a hemolytic strain of M bovis, was heat-labile. A live culture of strain 118F, at a ratio of 100 bacteria/neutrophil, released 97.7% of the 51Cr from labeled neutrophils. Neither a heat-killed preparation of M bovis 118F nor a live or heat-killed preparation of M bovis IBH63 (a nonhemolytic and nonpathogenic strain) induced significant (P greater than 0.05) release of 51Cr. Moraxella bovis 118F broth culture filtrates prepared for evaluation of leukocidic activity also were evaluated for hemolytic activity. These 2 toxic activities had several characteristics in common. Both were filterable, heat-labile, produced by a hemolytic strain, and were released during early logarithmic phase growth from broth cultures. Leukocidic and hemolytic activities were protected from degradation by phenylmethyl sulfonyl fluoride, a serine protease inhibitor. Leukocidic and hemolytic activities were dependent on calcium ions. Filtrate resulted in 54.1% 51Cr release from labeled neutrophils and contained 646.7 hemolytic U/ml, respectively, when saline (0.85% NaCl) + 10 mM CaCl2 solution was used as diluent. Neither saline solution nor saline + 10 mM MgCl2 solution supported leukocidic or hemolytic activity. Serum, obtained from several calves 10 to 38 days after M bovis inoculation, substantially neutralized leukocidic and hemolytic activities, compared with paired preinoculation serum samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation of some gram-negative glucose nonfermenting bacteria using miniaturized carbon sources assimilation tests

In water and soil the gram-negative nonfermenting bacteria play an important role in the biological mineralization process. To improve the methods for species differentiation of these heterogenous bacterial group, a total of 481 reference strains of gram-negative glucose nonfermenting bacteria belonging to the genera Pseudomonas, Alcaligenes, Bordetella, Agrobacterium, Moraxella, Acinetobacter, Flavobacterium and some CDC groups have been investigated for their ability to utilize 42 different carbon substrates with the help of a standardized and automated micromethod. Most species showed a typical pattern of carbon utilization and hence could be differentiated from each other within their genera. As already has been demonstrated by more clinical significant Pseudomonas species, this method proves to be a useful alternative to existing methods of differentiation, especially with representatives of the families Pseudomonadaceae and Alcaligenaceae.

Degradation of naphthalene-2,6- and naphthalene-1,6-disulfonic acid by a Moraxella sp

A naphthalene-2,6-disulfonic acid (2,6NDS)-degrading Moraxella strain was isolated from an industrial sewage plant. This culture could also be adapted to naphthalene-1,6-disulfonic acid as growth substrate. Regioselective 1,2-dioxygenation effected desulfonation and catabolism to 5-sulfosalicylic acid (5SS), which also could be used as the sole carbon source. 5SS-grown cells exhibited high gentisate 1,2-dioxygenase activity. Neither 5SS- nor gentisate-grown cells oxidized 2,6NDS; therefore, 2,6NDS or an early metabolite must serve as an inducer of the initial catabolic enzyme(s).

A note on hydrolysis of tributyrin by Branhamella and Neisseria

Sixty-three strains of Branhamella and Neisseria were tested by two methods for their ability to hydrolyse glycerol tributyrate. After the conventional plate test, gas liquid chromatographical (GLC) analysis of the agar medium was carried out to detect the hydrolysis product, butyric acid, and other volatile fatty acids. All strains of Branhamella catarrhalis, Neisseria caviae, N. cuniculi and N. ovis but no other Neisseria spp. gave positive results with the conventional test. With GLC, however, most strains of Branhamella and Neisseria were shown to liberate butyric acid. In addition, some strains liberated acetic and isovaleric acids. Greater amounts of butyric acid were produced by clinical strains, in particular B. catarrhalis, compared with reference strains. It was concluded that the conventional plate test for tributyrin hydrolysis differentiates B. catarrhalis, N. caviae, N. cuniculi and N. ovis from other Neisseria.

Supplement peptone agar--a simple carbohydrate degradation plate medium for the identification of Neisseria species

A carbohydrate degradation medium was developed for the detection of acid production by Neisseria species and Branhamella catarrhalis. A total of 223 clinical isolates were identified by Supplemented Peptone Agar and the results were compared with those of Cystine Trypticase Agar. Supplemented Peptone Agar and Cystine Trypticase Agar correctly identified 99.1% and 93.7% of the total strains respectively within 24 h. With Cystine Trypticase Agar method another 4% of the isolates could be identified but required an additional 24 h of incubation.

Role of dissolution rate and solubility in biodegradation of aromatic compounds

Strains of Moraxella sp., Pseudomonas sp., and Flavobacterium sp. able to grow on biphenyl were isolated from sewage. The bacteria produced 2.3 to 4.5 g of protein per mol of biphenyl carbon, and similar protein yields were obtained when the isolates were grown on succinate. Mineralization of biphenyl was exponential during the phase of exponential growth of Moraxella sp. and Pseudomonas sp. In biphenyl-supplemented media, Flavobacterium sp. had one exponential phase of growth apparently at the expense of contaminating dissolved carbon in the solution and a second exponential phase during which it mineralized the hydrocarbon. Phase-contrast microscopy did not show significant numbers of cells of these three species on the surface of the solid substrate as it underwent decomposition. Pseudomonas sp. did not form products that affected the solubility of biphenyl, although its excretions did increase the dissolution rate. It was calculated that Pseudomonas sp. consumed 29 nmol of biphenyl per ml in the 1 h after the end of the exponential phase of growth, but 32 nmol of substrate per ml went into solution in that period when the growth rate had declined. In a medium with anthracene as the sole added carbon source, Flavobacterium sp. converted 90% of the substrate to water-soluble products, and a slow mineralization was detected when the cell numbers were not increasing. Flavobacterium sp. and Beijerinckia sp. initially grew exponentially and then arithmetically in media with phenanthrene as the sole carbon source. Calculations based on the growth rates of these bacteria and the rates of dissolution of phenanthrene suggest that the dissolution rate of the hydrocarbon may limit the rate of its biodegradation.

Infectious bovine keratoconjunctivitis: seasonal variation in cultural, biochemical and immunoreactive properties of Moraxella bovis isolated from the eyes of cattle

The eyes of 20 young cattle were examined over an 18 month period in which 12 members of the group contracted infectious bovine keratoconjunctivitis (IBK). On each of 23 occasions cultural, biochemical and immunoreactive properties of up to 6 isolates of Moraxella bovis derived from each eye were determined. Relationships between the clinical response of eyes, phenotypic properties of M. bovis and annual variations in the level of solar ultraviolet radiation of 280 to 320 nm wavelength were examined. M. bovis was isolated from all IBK-affected and some unaffected eyes less than one month after the maximum annual level of the mean weekly UV radiation (2,840 mWh.m-2 X nm-1) was recorded. A high proportion of M. bovis from IBK lesions were simultaneously active in haemolysis, agar corrosion, gelatin liquefaction and litmus milk peptonisation. Some of these characteristics showed marked dissociation despite consistent reactivity in the fluorescent antibody test, which had a sensitivity and specificity of 95%. Fall in the mean weekly level of UV radiation below 1,438 mWh X m-2 X nm-1 in autumn was accompanied by healing of ulcers, persistent scar formation and a decline in the number of M. bovis isolated from affected eyes. A slower decline in the number of M. bovis isolated from apparently healthy eyes occurred in the winter and occasional fresh IBK lesions occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Rapid NFT system and conventional methods for identification of nonsaccharolytic gram-negative bacteria

This study examined the Rapid NFT system (Analytab Products, Plainview, N.Y.) to determine its ability to accurately identify 229 clinical isolates of mostly nonsaccharolytic gram-negative rods. Identifications were classified by the following scheme: correct (corresponding to excellent, very good, good, or acceptable identification as listed in the code book); low discrimination (correct identification among a range of listed possibilities, with additional tests necessary for accurate identification); incorrect. Correct identification was considered correct to species and subspecies for all organisms except Alcaligenes faecalis and "Alcaligenes odorans"; "A. faecalis/odorans" was considered a correct response. By using these criteria, 71.6% of the strains were correctly identified, 17.9% were identified with low discrimination, and 10.5% were incorrectly identified. When consideration was made for incorrect identification resulting from taxonomic problems (e.g., Alcaligenes and Moraxella spp.), incorrect identifications fell to 5.2%. The Rapid NFT system was truly rapid and was easy to use and interpret. Its use of carbon substrate assimilation enables it to provide more accurate identification of medically important nonsaccharolytic bacteria than do other commercially available systems.

Defined medium for Moraxella (Branhamella) catarrhalis

A defined medium for growth of 24 strains of Moraxella (Branhamella) catarrhalis was devised. This medium (medium B4) contains sodium lactate as a partial carbon source, proline as both a partial carbon source and a partial nitrogen source, aspartate as a partial nitrogen source, and the growth factors arginine, glycine, and methionine. Either aspartate, glutamate, or proline could serve as sole nitrogen source, but growth occurred at a significantly better rate if proline was present together with either aspartate or glutamate, or with both aspartate and glutamate. With the exception of strain ATCC 23246, all the strains had an absolute requirement for arginine and either a partial or absolute requirement for glycine. The concentration of glycine required for optimal growth was found to be relatively high for an amino acid growth factor. Heart infusion broth was found to be growth inhibitory for spontaneous mutants of one strain able to grow in the absence of arginine, and such mutants reverted readily to arginine dependence accompanied by the ability to grow faster on the complex medium. Growth rates in the defined medium B4 were enhanced by the simultaneous addition of asparagine, glutamate, glutamine, leucine, lysine, histidine, and phenylalanine.

Microbial mineralization of ring-substituted anilines through an ortho-cleavage pathway

Moraxella sp. strain G is able to utilize as sole source of carbon and nitrogen aniline, 4-fluoroaniline, 2-chloroaniline, 3-chloroaniline, 4-chloroaniline (PCA), and 4-bromoaniline but not 4-iodoaniline, 4-methylaniline, 4-methoxyaniline, or 3,4-dichloroaniline. The generation time on PCA was 6 h. The pathway for the degradation of PCA was investigated by analysis of catabolic intermediates and enzyme activities. Mutants of strain G were isolated to enhance the accumulation of specific pathway intermediates. PCA was converted by an aniline oxygenase to 4-chlorocatechol, which in turn was degraded via a modified ortho-cleavage pathway. Synthesis of the aniline oxygenase was inducible by various anilines. This enzyme exhibited a broad substrate specificity. Its specific activity towards substituted anilines seemed to be correlated more with the size than with the electron-withdrawing effect of the substituent and was very low towards anilines having substituents larger than iodine or a methyl group. The initial enzyme of the modified ortho-cleavage pathway, catechol 1,2-dioxygenase, had similar characteristics to those of corresponding enzymes of pathways for the degradation of chlorobenzoic acid and chlorophenol, that is, a broad substrate specificity and high activity towards chlorinated and methylated catechols.

Moraxella bovis hemolysin

Moraxella bovis hemolysin was readily filterable through polycarbonate membrane filters, but not through nitrocellulose filters. The hemolysin was filterable through polycarbonate filters with pore diameters of greater than or equal to 0.015 micron (APD). Of the hemolytic activity of cell-free filtrates, 74% could be pelleted by ultracentrifugation at 100,000 X g for 2 1/2 hours. Hemolytic activity could be demonstrated in preparations of outer membrane fragments isolated from log-phase cultures. Hemolysin in M bovis broth cultures reached a maximum concentration in late logarithmic phase (4.5 hours after inoculation) and declined thereafter. Hemolysin was inactivated by heat, trypsin, formalin, and lyophilization.

Novel transformations of i-cholesterol and 6 beta-methoxy-i-cholesterol by Moraxella sp

A soil microorganism was isolated by the enrichment culture technique using cholesterol as the sole source of carbon. The organism has been identified as belonging to the genus Moraxella. With this organism two novel biotransformations of sterols were observed viz. (1) isomerization of 3 alpha,5 alpha-cyclocholestan-6 beta-ol (i-cholesterol) to cholesterol, (2) demethylation of 6 beta-methoxy-3 alpha,5 alpha-cyclocholestane (6 beta-methoxy-i-cholesterol) to i-cholesterol with subsequent isomerization to cholesterol. The enzymes responsible for these transformations were shown to be inducible. The pH optimum of the partially purified i-cholesterol isomerase was found to be 8.4. The apparent Km value for i-cholesterol was 1.43 microM. A plausible mechanism for the i-cholesterol isomerization has been discussed.

The bacterial biogenesis of isobutyraldoxime O-methyl ether, a novel volatile secondary metabolite

Production of the volatile metabolite, isobutyraldoxime O-methyl ether (IBME) by a Moraxella-like organism NCIB 11650 was investigated under a variety of environmental conditions using gas chromatography. Under aerobic conditions up to 10 micrograms IBME ml-1 was produced on mineral salts media containing 0.5% (w/v) glucose or succinate as sole C source with 0.1% (w/v) NH4Cl as sole N source. Exogenous L-valine further stimulated IBME formation up to 25 micrograms ml-1 but supplementation of the medium with D-isomer or other amino acids had little effect on IBME production and did not lead to the appearance of analogues of IBME. Trapping experiments using [14C]valine confirmed that IBME was derived from this amino acid. Several other bacterial species examined, e.g. Alcaligenes sp. NCIB 11652, another Moraxella-like organism NCIB 11651 and Pseudomonas sp. NCIB 11653 also produced IBME under similar conditions. The Alcaligenes strain synthesized up to 20 micrograms ml-1 in the absence of valine and up to 90 micrograms ml-1 in its presence. The product of IBME exhibited many features characteristic of the formation of a secondary metabolite. Thus biosynthesis was confined to a narrower range of temperature than cell division, was almost completely suppressed by 300 mM-phosphate and was inhibited by high concentrations of readily utilizable C sources. Although IBME synthesis in the Moraxella-like organism NCIB 11650 appeared to be growth-related, its formation by both the Alcaligenes sp. and the Moraxella-like organism NCIB 11651 was delayed until the late-exponential and early-stationary phases of growth. The biological significance of this novel class of secondary metabolite is discussed and a possible biosynthetic route proposed.

Coliform inhibition by bacteriocin-like substances in drinking water distribution systems

Bacterial isolates from an unchlorinated potable groundwater system and a chlorinated surface water system were screened by an agar overlay method for the ability to produce bacteriocin-like substances (BLS) inhibitory to the growth of Escherichia coli, Klebsiella sp., and Enterobacter aerogenes. The production of coliform-specific BLS by noncoliform bacteria varied with the site and date of isolation as well as the genus of the producer strain. A total of 448 bacterial isolates were screened from the chlorinated system, and 22.1% produced BLS specific for at least one of the three coliforms. In the unchlorinated system, 7.9% (n = 696) possessed this ability. Flavobacterium/Moraxella comprised 57.1% of all bacteria (from both systems) producing BLS. The possibility that BLS interfere with coliform detection in standard bacteriological water quality tests is discussed.

Identification of isobutyronitrile and isobutyraldoxime O-methyl ether as volatile microbial catabolites of valine

G.l.c.--mass-spectral analysis of headspace above cultures of Aeromonas and Moraxella spp. indicates the presence of isobutyronitrile, isobutyraldoxime O-methyl ether, methacrylonitrile and possibly methacrylaldoxime O-methyl ether. Accumulation of these catabolites is maximal under low oxygen concentrations and is enhanced by enrichment of the medium with valine. Isobutyraldoxime O-methyl ether is established as the compound observed but not identified in previous studies with other bacterial species involved in spoilage of meat and chicken.

The identification of Moraxella bovis and Neisseria ovis from the eyes of cattle and sheep

The cultural characteristics of Moraxella bovis and Neisseria ovis from eyes of cattle and sheep were examined to determine which tests precisely identified the isolates. The elongation test to distinguish the bacillary M vovis from the coccal N ovis, the nitrate reduction and the litmus milk tests were found to be the most reliable.

High-resolution gas chromatographic profiles of volatile organic compounds produced by microorganisms at refrigerated temperatures

Three different strains of bacteria isolated from spoiled, uncooked chicken were grown in pure culture on Trypticase soy agar supplemented with yeast extract. The volatile organic compounds produced by each culture were concentrated on a porous polymer precolumn and analyzed by high-resolution gas chromatographic mass spectrometry. Twenty different compounds were identified. Both qualitative and quantitative differences in the chromatographic profiles from each culture were found.

Production and characterization of Moraxella bovis hemolysin

Moraxella bovis hemolysin was produced in trypticase soy broth and maximum hemolytic activity of the culture was observed during the logarithmic phase of growth. The hemolysin was filterable through a 0.22-micrometer (APD) membrane filter, heat labile, and destroyed by treatment with formalin or trypsin. There was no difference in the amount of hemolysin production by rough or smooth colony types of an isolate, although differences were observed between 2 different isolates. Partial requirement of a sulfhydryl group and divalent cations were suggestive of an enzymatic nature of M bovis hemolysin.