Strains Of Coryneform Bacteria Research Articles

THE ACCELERATED METHOD FOR IDENTIFICATION OF PATHOGENIC CORYNEBACTERIUM

Abstract. The detection of cystinase activity is one of most important tests in the laboratory diagnosis of diphtheria, giving the opportunity to differentiate potential toxigenic species from other coryneform bacteria. The original recipe of Pizu media for detection of cystinase activity, proposed in 1939–1940, was modified several times (1982, 1989) for different reasons. In the last modification the Pizu media was prepared by using the AGV media as a nutritional base. We suggest a modification of Pizu media using Mueller-Hinton agar as nutritional basis. The Mueller-Hinton agar has a number of advantages: higher nutritional value, standardization, transparency and availability. A positive result is defined within 2–4 hours after inoculation of enough quantity of material (pure culture or C. diphtheriaе in association with other microorganisms) as a brown halo surrounding black colonies. The brown halo does not appear in the upper part of the media (0,5–1 cm). The modified media was checked with 21 strains of C. diphtheriaе (tox+), nine strains of coryneform bacteria, control strains NCTC 10648, NCTC 10356, NCTC 3984. The modified Pizu media is registered in the RA mental property agency as an invention (no. 1877 A2, 15.12.2006).

Aptitude of cheese bacteria for volatile S -methyl thioester synthesis. II. Comparison of coryneform bacteria, Micrococcaceae and some lactic acid bacteria starters

Various strains of coryneform bacteria, Micrococcaceae and commercial starters of Lactococcus lactis and Leuconostoc were compared for their aptitude to form S-methyl thioesters. Resting cells were incubated with methanethiol alone at pH 7 and in conjunction with a mixture of straight, branched and hydroxy short-chain fatty acids up to C6 at pH 7 and 5. Results showed that all the strains synthesized at least S-methyl thioacetate, with strains that were low and high producers in each group. This is the only thioester formed in small amount by Leuconostoc. Brevibacterium linens (six strains) and Micrococcaceae (five strains) were able to form branched-chain thioesters especially from their intracellular fatty acids at neutral pH, and straight-chain thioesters mostly from exogenous fatty acids at acid pH. Coryneform bacteria other than B. linens (four strains) and L. lactis (four starters) synthesized thioesters up to S-methyl thiobutyrate from endogenous or exogenous fatty acids but not branched-chain ones, except for one starter which formed a very little thioisovalerate. Some particular effects of pH and added fatty acids revealed differences between species or strains in their specific enzymatic systems.

Sanguibacter inulinus sp. nov.

Six strains of coryneform bacteria were isolated from blood samples obtained from healthy cows. Phenotypic and molecular genetic studies showed that these isolates represent a new species of the genus Sanguibacter, for which the name Sanguibacter inulinus is proposed. The type strain of S. inulinus is strain ST-50 (= NCFB 3024).

Presence of mrr- and mcr-like restriction systems in coryneform bacteria

Efficient transformation of Brevibacterium flavum MJ233C and Corynebacterium glutamicum ATCC 31831 (up to 5.0 × 10 7 transformants/μg DNA) depends on the source of plasmid DNA. The transformation efficiencies of B. flavum MJ233C and C. glutamicum ATCC 31831 increased nearly 10 3-fold when plasmid DNA was isolated from the recipient strain itself or from a damdcm Escherichia coli mutant, as compared with DNA passed through a modification-proficient E. coli strain. These results suggest the presence of a methyl-specific restriction system in certain strains of coryneform bacteria. In addition, electroporation conditions were optimized.

Production of volatile compounds in liquid cultures by six strains of coryneform bacteria

The aromatic profiles of four strains of Brevibacterium linens, one strain of Brevibacterium sp. and one strain of Microbacterium sp. were determined with some pure cultures of these microorganisms in standard trypcase soy liquid medium, which enabled four of these six strains to produce flavour compounds of ripened cheese. Thirty-two flavour compounds were identified by gas chromatography and mass spectrometry. The identified flavour compounds included the following: fatty acids, alcohols, methylketones, sulphur compounds, aromatic compounds and a pyrazine. Some important differences were found among the six strains studied. The four strains of B. linens had similar flavour profiles. Their typical flavour was probably due to dimethyltrisulphide. The two other strains did not appear to produce this compound. Three strains produced significant amounts of the floral aromas phenylethanol and phenylpropanone.

Phylogenetic analysis of some ?-diaminopimelic acid-containing coryneform bacteria from human skin: description of Propionibacterium innocuum sp. nov.

A new species, Propionibacterium innocuum, is proposed to accommodate strains of coryneform bacteria from human skin with phenotypic characters similar to those of the classical propionibacteria but differing in exhibiting primarily aerobic respiration and possessing a unique cell wall composition in which LL-diaminopimelic acid and arabinose occur together. The partial 16S rRNA sequence confirms an affinity with the genus Pro-pionibacterium and indicates that the species represents a distinct line within the genus. The type strain of Propionibacterium innocuum is NCTC 11082.

Do Cutaneous Coryneform Bacteria Produce Short-Chain Fatty Acids in vitro?

According to an opinion shared by many, human axillary and inguinal odour is related to short-chain fatty acids produced by gram-positive bacteria. Especially coryneform bacteria are said to produce these odiferous substances. After sampling 22 different strains of coryneform bacteria we cultured them for 48 h in a rich medium. Short-chain fatty acids were extracted afterwards by shaking the liquid medium with ether. Gas chromatography was used for detection. Only one of the tested bacteria produced propionic acid. Acetic acid, (iso)butyric acid or (iso)valeric acid could never be detected. The production of substances of the short-chain fatty acid type might, however, be a consequence of the particular substrate found under physiologic conditions by these organisms in human apocrine sweat. The theory that the metabolism of these skin bacteria necessarily produces short-chain fatty acids could not be supported. Another explanation might be that unspecific secreted enzymes of the bacteria are responsible for the production of short-chain fatty acids by a cleavage of skin surface lipids.

Three New Murein Types in Coryneform Bacteria Isolated from Activated Sludge

Summary The cell walls of 4 strains of coryneform bacteria (designated S1, S2, S4, S27) isolatedfrom activated sludge contain three new murein types of the cross-linking group B. In all cases the interpeptide bridge contains a D-diamino acid. In the murein of strains S1 and S2, D-2,4-diaminobutyric acid residues function as interpeptide bridges between the α-carboxyl group of D-glutamic acid and the carboxyl group of the terminal D-alanine residue of an adjacent peptide subunit. The interpeptide bridge in the murein of strain S4 consists, however, of the dipeptide N 5 -(Gly)-D-Orn, and that in strain S27 of the dipeptide N 2 (L-Thr)-D-Dab. Position 3 of the peptide subunit is taken by homoserine residues in strains S1 and S2, by L-ornithine residues in strain S4 and by L-alanine in strain S27. According to the classification of Schleifer and Kandler (1972) the murein types L-HsrD-Glu-D-Dab (S1, S2) and L-Orn D-Glu-Gly-D-Orn (S4) belong to the known murein variations B2s and B2α respectively. For the classification of the new murein type of strain S27 (L-Ala D-Glu-D-Dab-Thr), the new murein variation B2δ is suggested.

Capsule-Producing Coryneform Bacteria Associated with Stickiness in Cotton

Sticky cotton samples received at the Textile Research Center of Texas Tech University for processing had a significantly higher proportion of white colonies (many of which were coryneform bacteria) than non-sticky cotton samples, al though the same kinds of organisms were present on both kinds of cottons. Four representative strains of coryneform bacteria were isolated from samples of both sticky and non-sticky cotton and examined for their ability to produce extracellular carbohydrates. When grown on thioglycollate agar, two of the strains produced copious amounts of extracellular polysaccharide in the form of a capsule. All four strains produced this material when they were grown in a liquid medium. Paper chromatography of the hydrolyzed capsular material revealed the presence of both glucose and galactose, and both glucose and galactose were present in hydrolyzed extracts of sticky cotton. Since previous investigators found carbohydrates were associated with stickiness in cotton, it is possible that capsule-forming coryneform bacteria contribute to stickiness when they constitute a significant proportion of the bacteria present on cotton.

Numerical cluster analysis of the coryneform bacteria from activated sludge

Summary Two hundred and seventy-three strains of coryneform bacteria mainly isolated from activated sludge were tested for 135 physiological characters. In addition, one hundred and ten named reference strains were included for comparison. The data were subjected to numerical analysis. The results showed that the strains clustered into 5 groups, each of which consisted of several subgroups. The isolates were identified as members of the genera Arthrobacter, Nocardia, Mycobacterium, Rhodococcus, Microbacterium, Cellulomonas, Curtobacterium and Corynebacterium . The bacterial flora of the activated sludge from dairy sewage mainly consisted of strains of the genera Corynebacterium, Microbacterium and Rbodococcus . That of sludge from municipal sewage predominantly comprised strains of the genera Arthrobacter, Corynebacterium and Microbacterium . Twenty-five of the tests used were found to be particularly useful in discriminating between the main clusters. When the strains were retested and classified on the basis of these tests, the resultant groupings were very similar to those obtained in the full analysis.

Preservation of bacteria by freezing at moderately low temperatures

In order to get some basic information for the development of a long-term preservation method by freezing at moderately low temperatures, the viability of 259 strains belonging to 32 genera and 135 species was measured. Cells were suspended in 10% glycerol and stored at −53 °C for 16 months. About 93%, 88%, and 74% of aerobic bacteria gave viable cell counts higher than 10 5/ml, 10 6/ml, and 10 7/ml, respectively. About 10% of gram-positives and 3% of gram-negatives gave viable cell counts lower than 10 5/ml. There seemed to be some species—and genus—specificity with respect to viability after frozen storage and liquid paraffin-seal storage. Strains of coryneform bacteria, genera of the family Enterobacteriaceae, and the genus Pseudomonas were generally resistant. Pseudomonas putrefaciens proved to be specifically sensitive. Lactic acid bacteria were subject to sublethal injury, requiring special recovery media. Psychrophilic bacteria were very susceptible to frozen storage. All the tested strains of acetic acid bacteria survived frozen storage well both in 10% glycerol and in 10% honey at −28 °C for 4.5 years. Honey proved to be a better adjuvant for frozen storage than glycerol. It was suggested from the results that for many kinds of bacteria, long-term preservation by freezing at moderately low temperatures might be possible when appropriate procedures are applied.