Discrimination of Corynebacterium glutamicum, Brevibacterium flavum and Brevibacterium lactofermentum by restriction pattern analysis of DNA adjacent to the hom gene

Different strains of Corynebacterium glutamicum, Brevibacterium flavum, and Brevibacterium lactofermentum were analysed for restriction fragment length polymorphism using the homoserine dehydrogenase gene (hom) as a probe. The hybridization patterns obtained PvuII- or Asp700-restriction of chromosomal DNA were specific and distinguishable for each of the three species and identical for the different strains of each species. Thus, the method employed allows rapid distinction of Corynebacterium glutamicum, Brevibacterium flavum, and Brevibacterium lactofermentum. The former species could also be discriminated from the latter two by its resistance to 0.5 g/l of the methionine analog ethionine.     

The derepression of enzymes of de novo pyrimidine biosynthesis pathway in Brevibacterium ammoniagenes producing uridine-5-monophosphate and uracil

A mutant of Brevibacterium ammoniagenes producing large quantities of UMP and uracil is described. The mutations render bacteria braditrophic for arginine, sensitive to adenine, resistant to rifampicin and pyrimidine analogues 5-fluorouracil, 5-fluorouridine, azauracil and thiouracil. The activities of enzymes involved in the UMP biosynthesis, i.e. orotate phosphoribosyltransferase, orotate-5-monophosphate decarboxylase, dihydroorotate oxidase, are 4-, 3.5- and 4.5-fold higher in the mutant than in the parent strain when grown in minimal medium. The synthesis of these enzymes in mutant cells is not repressed in the presence of exogenous Ura. True revertants, which completely restore the wild-type phenotype, occur among the Arg+ clones. The nature of the mutation is discussed.     

Parameters of unbalanced growth and reversible inhibition of deoxyribonucleic acid synthesis in Brevibacterium ammoniagenes ATCC 6872 induced by depletion of Mn2+. Inhibitor studies on the reversibility of deoxyribonucleic acid synthesis

Unbalanced growth induced by depletion of manganese ions was a prerequisite for production of ribonucleotides in a high salt mineral medium with the wildtype strain Brevibacterium ammoniagenes ATCC 6872. The concentration of manganese strictly controlled the overall deoxyribonucleic acid (DNA) synthesis, whereas ribonucleic acid (RNA), protein and cell wall synthesis remained essentially unimpaired in the manganese-lacking cells.The reversibility of inhibition of overall DNA synthesis was shown by enhanced incorporation (up to threefold compared to the cultures supplied with sufficient manganese) of [8-¹⁴C] adenine into alkali-stable, trichloroacetic acid-insoluble material after subsequent addition of 10 M MnCl₂ to 15 h-old depleted cultures.The results of inhibitor studies on the restoration of overall DNA synthesis due to subsequent addition of manganese ions to depleted cultures suggest that ribonucleotide reduction is the primary target of the manganese starvation during nucleotide fermentation with Brevibacterium ammoniagenes ATCC 6872.     

Preparation of Four Geometric Isomers of (11E)-4,6,11-Hexadecatrienal and Their Effect toward Male Eri-Silk Moths

Four geometric isomers of (11E)-4,6,11-hexadecatrienal were prepared, and their pheromone activity towards male eri-silk moths was evaluated. The EAG activity of each isomer was determined by the EAG-GLC method in order of increasing activity to be (4Z,6E,11E)- and (4E,6E,11E)?? (4E,6Z,11E) ?? (4Z,6Z,11E)-hexadecatrienal.     

Phytotoxic Metabolites of Phyllosticta sp.

The additional new metabolites, named phyllostine (II) and 3-chloro-2,5-dihydroxybenzyl alcohol (III) from the cultural filtrates of Phyllosticta sp. have been isolated. The chemical structure of II have been established by spectral studies and chemical conversion from the known I, and the chlorine-containing metabolite (III) by spectral and synthetic studies. The metabolite (II) exhibits the similar phytotoxic effects as I, but the metabolite III does less phytotoxicity than I and II on the leaf test.     

Discovering lactic acid bacteria by genomics

This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, nvironmental habitat, and its role in fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing of key statistics and interesting genomic features. These efforts will revolutionize our molecular view of Gram–positive bacteria, as up to 15 genomes from the low GC content lactic acid bacteria are expected to be available in the public domain by the end of 2003. Our collective view of the lactic acid bacteria will be fundamentally changed as we rediscover the relationships and capabilities of these organisms through genomics.     

Brevibacterium frigoritolerans a novel entomopathogen of Anomala dimidiata and Holotrichia longipennis (Scarabaeidae: Coleoptera)

We describe the isolation, biochemical characterization, phylogenetic analysis, and pathogenecity of a novel entomopathogenic bacterium Brevibacterium frigoritolerans to first instar larvae of Anomala dimidiata and Holotrichia longipennis. The almost full length 16S rRNA sequence of the bacterium has 99% identity with the type strain of B. frigoritolerans, while phylogenetic analysis revealed that the isolate formed a tightly linked branch with the type strain of B. frigoritolerans. Under in vitro bioassay conditions, the isolate infected and caused 89±5.4 and 74±7.7% mortality, in first instar larvae of A. dimidiata and H. longipennis, respectively. The infected larvae exhibited bacteremia like symptoms and mortality occurred between the second and fifth weeks after inoculation. This is an early report on the entomopathogenic potential of the hitherto lesser-known bacterium Brevibacterium frigoritolerans.