Morphology and physiology of coryneform bacteria

Four groups of coryneform bacteria, viz. soil arthrobacters, orange cheese coryneforms, orange sea-fish coryneforms and non-orange cheese coryneforms, were studied as regards morphological and physiological features. The soil arthrobacters can be divided into a simplex and a globiformis group on the basis of their ability of utilizing a number of carbon sources. The group of the orange cheese coryneforms was found to be rather homogeneous, in contrast to the groups of the orange sea-fish coryneforms and the non-orange cheese coryneforms, some strains of which deviated from the others of their group as to the majority of the characteristics tested. Mainly the physiological characteristics of each of the groups justify the division of the coryneforms into the four chief groups mentioned.     

Genetic engineering of coryneform bacteria

The coryneforms are a diverse group of bacteria which includes animal and plant pathogens as well as non-pathogenic bacteria. Although they are of significant economic and health importance, their genetics is poorly understood. The development of genetic engineering techniques for coryneforms and initial gene cloning studies are discussed.     

Plasmids in coryneform bacteria of human origin

A study of plasmids in coryneform bacteria isolated from human sources is reported. Seventy of 269 strains possessed a total of 89 plasmids. These were shown to be of varying sizes and in some cases of varying structures by endonuclease restriction digest. In six of 20 strains antibiotic resistance was cured with loss of the plasmid. The diversity of plasmids is emphasized.     

Development cycles of coryneform and Nocardia-like bacteria

The growth cycles and the types of cell separation were studied in a microchamber with the collection strains of Brevibacterium ammoniagenes ATTC 6871, B. helvolum ATCC 19239, B. linens CCM 47 and ATCC 9174, B. maris VKM B-464 and B. stationis ATCC 14403, as well as with the strains of the genus Rhodococcus isolated from soils, viz. R. maris sp. nov. IMB 283 and R. luteus sp. nov. IMB 385. According to the increasing complexity of cellular morphological transformation in the life cycle, the organisms may be arranged in a series: R. maris -- B. ammoniagenes -- B. stationis -- B. linens -- B. helvolum -- R. luteus. The first three organisms are characterized by the snapping type of separation of short rod-like daughter cells. The cells of B. linens separate by both the snapping and bending types. The coccoid cells of B. helvolum ATCC 19239 produce many buds which are transformed into rod-like cells in the course of growth. In the log phase of growth, both true and false branching of the cells is observed; the latter is the result of a peculiar growth of the ends in the separated cells of B. helvolum. The cells of R. luteus form a rudimentary, rapidly fragmenting mycelium whose rod-like elements divide then by binary fission; the daughter cells separate the bending and snapping types.     

Plasmids in coryneform bacteria of human origin

A study of plasmids in coryneform bacteria isolated from human sources is reported. Seventy of 269 strains possessed a total of 89 plasmids. These were shown to be of varying sizes and in some cases of varying structures by endonuclease restriction digest. In six of 20 strains antibiotic resistance was cured with loss of the plasmid. The diversity of plasmids is emphasized.     

Numerical taxonomy of certain coryneform bacteria

da Silva, G. A. Nigel (Iowa State University, Ames), and John G. Holt. Numerical taxonomy of certain coryneform bacteria. J. Bacteriol. 90:921-927. 1965-An electronic computer was used to sort 32 strains of coryneforms into groups with the tree-sort program. The similarity values obtained in this procedure were then used to construct a dendrogram depicting the phenetic resemblance among the taxa. The results indicated that all the phytopathogens studied were sufficiently distinct from the type species, Corynebacterium diphtheriae, to be excluded from the genus Corynebacterium. The grouping of some of the phytopathogens with Microbacterium lacticum is discussed. C. fascians appeared so distinct from the other strains studied that it should probably be excluded from the Corynebacteriaceae. The phenetic resemblance of Brevibacterium linens and Arthrobacter globiformis was emphasized, and the new combination, Arthrobacter linens, was proposed. In addition, because of distinct dissimilarity from the type species, it would seem desirable to exclude Arthrobacter tumescens from the genus Arthrobacter. The justification for classifying Kurthia zopfii in a family separate from the Corynebacteriaceae would appear to be open to serious question. It was concluded that the present taxonomic positions of Listeria monocytogenes, Cellulomonas biazotea, and Cellulomonas fimi are satisfactory.     

Phenylalanine and tyrosine catabolism in some cheese coryneform bacteria

Abstract 23 cheese coryneform bacteria (14 orange, 3 white, and 6 yellow-pigmented) were examined for five enzymes of two branch-point steps in the catabolic pathways of l -phenylalanine and l -tyrosine. Orange cheese coryneforms ( 'Brevibacterium linens' ) catabolized th amino acids by transamination and the benzene ring was cleaved by 3, 4-dihydroxyphenylacetate-2, 3-dioxygenase. Both enzymes appear to be inducible. Yellow and white strains possessed non-inducible low activity of aminotransferase and lacked completely benzene ring cleavage enzymes.     

Identification of plasmid partition function in coryneform bacteria

We have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. This fragment was able to stabilize the unstable plasmids in cis but not in trans.     

Identification of plasmid partition function in coryneform bacteria.

We have identified and characterized a partition function that is required for stable maintenance of plasmids in the coryneform bacteria Brevibacterium flavum MJ233 and Corynebacterium glutamicum ATCC 31831. This function is localized to a HindIII-NspV fragment (673 bp) adjacent to the replication region of the plasmid, named pBY503, from Brevibacterium stationis IFO 12144. The function was independent of copy number control and was not associated directly with plasmid replication functions. This fragment was able to stabilize the unstable plasmids in cis but not in trans.     

Flagellated coryneform bacteria from the intestine of earthworms

Summary Representative strains of distinctly flagellated, but doubtfully motile, coryneform bacteria were isolated from the intestine of Indian earthworms. Their morphological, cultural, physiological and nutritional characters are described, and their taxonomic position discussed.     

Isoprenoid quinones in the classification of coryneform and related bacteria.

Menaquinones were the only isoprenoid quinones found in 85 of the 95 coryneform bacteria examined. Dihydromenaquinones having nine isoprene units were the main components isolated from Corynebacterium bovis, from other glutamic acid-producing strains, and from Arthrobacter globiformis and related species. Dihydromenaquinones with eight isoprene units were found in Brevibacterium linens, the remaining Corynebacterium species and strains probably belonging to the genus Rhodococcus. Tetrahydromenaquinones with eight isoprene units were found in Arthrobacter simplex and Arthrobacter tumescens, and with nine isoprene units in Cellulomonas and Oerskovia. Kurthia and Curtobacterium were characterized by menaquinones with seven and nine isoprene units, respectively, and Microbacterium lacticum and Corynebacterium aquaticum had comparable amounts of menaquinones with 10 and 11 isoprene units. Strains received as Brevibacterium leucinophagum, Corynebacterium autotrophicum, Corynebacterium nephridii, Mycobacterium flavum, Mycoplana rubra and Protaminobacter ruber contained uniquinones as their sole isoprenoid quinones. The isoprenoid quinone data correlate well with major trends in coryneform taxonomy and are of value in the classification of coryneform and related bacteria.     

Industrial production of amino acids by coryneform bacteria

In the 1950s Corynebacterium glutamicum was found to be a very efficient producer of L-glutamic acid. Since this time biotechnological processes with bacteria of the species Corynebacterium developed to be among the most important in terms of tonnage and economical value. L-Glutamic acid and L-lysine are bulk products nowadays. L-Valine, L-isoleucine, L-threonine, L-aspartic acid and L-alanine are among other amino acids produced by Corynebacteria. Applications range from feed to food and pharmaceutical products. The growing market for amino acids produced with Corynebacteria led to significant improvements in bioprocess and downstream technology as well as in molecular biology. During the last decade big efforts were made to increase the productivity and to decrease the production costs. This review gives an overview of the world market for amino acids produced by Corynebacteria. Significant improvements in bioprocess technology, i.e. repeated fed batch or continuous production are summarised. Bioprocess technology itself was improved furthermore by application of more sophisticated feeding and automatisation strategies. Even though several amino acids developed towards commodities in the last decade, side aspects of the production process like sterility or detection of contaminants still have increasing relevance. Finally one focus of this review is on recent developments in downstream technology.     

Chemotaxonomic differentiation of coryneform bacteria isolated from biofilters.

Coryneform bacteria that were isolated from biofilters which are used for waste gas treatment of animal-rendering plant emissions were differentiated and partially identified by using chemotaxonomic methods. On the basis of the results of a numerical analysis of whole-cell fatty acid profiles, 79 isolates were divided into two major groups; the members of the first group contained saturated and monounsaturated fatty acids, whereas the members of the second group were characterized by iso- and anteiso-branched fatty acids. Division into subclusters was based mainly on quantitative differences in fatty acid composition and was confirmed by the results obtained for additional chemical markers (e.g., respiratory quinones, mycolic acids, polar lipids, cell wall amino acids, and whole-cell sugar patterns). By combining the results obtained for chemotaxonomic analyses that were performed for strains containing saturated and monounsaturated fatty acids, we were able to identify the genus Corynebacterium (two Corynebacterium species were differentiated on the basis of the occurrence of tuberculostearic acid), the genus Gordona, and the genus Mycobacterium. Among the strains that produced iso-anteiso fatty acid patterns, one subgroup was affiliated with the "nicotianae" group of the genus Arthrobacter; however, some strains contained a new combination of chemical markers. Peptidoglycan type A4 alpha, L-Lys-Gly-L-Glu was combined with menaquinones MK-7 and MK-8, whereas peptidoglycan type A4 alpha, L-Lys-L-Glu occurred together with MK-8 and MK-9. The second subgroup was characterized by a new type B peptidoglycan and MK-11, as well as small amounts of MK-12. Differentiation that was based first on chemotaxonomy and second on physiology gave reliable results. Thus, coryneform strains with new characteristics were isolated from biofilters.     

Taxonomic studies on some gram-positive coryneform hydrogen bacteria

Recently isolated coryneform hydrogen bacteria were investigated under taxonomical aspects. Strains 7 C, RH 10, and 14 g are characterized by the snapping type of cell division, 68.5 to 69.7% GC content, dl-diaminopimelic acid in the cell wall, content of metachromatic granules, weak utilization of sugars and inhibitory effect of citrate. The strains are placed to the group 1—genus Corynebacterium—of the classification of coryneform bacteria of Yamada and Komagata (1972) and the name Corynebacterium autotrophicum sp.nov. is proposed.Strains 11 X and RH 12 are characterized by the bending type of cell division, a GC content of 70.2 and 70.5%, ll-diaminopimelic acid in the cell wall, absence of metachromatic granules, utilization of several sugars and no changes in cell morphology by citrate. The strains have to be placed to group 6 of coryneform bacteria.