Current Microbiology

Tilak, Kolluru; Schneider, Klaus; Schlegel, Hans

doi: 10.1007/BF01577194pmid: N/A

Out of 15 strains ofAzospirillum spp. isolated from the roots of different plants, only 4 (CY, M, CC, and AM) were able to grow autotrophically with H2 and CO2. All of them showed H2 uptake in the presence of oxygen or methylene blue and ribulose-1,5-bisphosphate carboxylase activity. Among the four strains, strain CC isolated from the roots ofCenchrus cilliaris showed maximum H2+O2 uptake (32.5 μl/min. mg protein) as well as H2 uptake in the presence of methylene blue (41.4 μl/min·mg protein) and also the maximum activity of ribulose-1,5-bisphosphate carboxylase (17 units [U]/g protein). The doubling time of this strain under autotrophic growth conditions and at low oxygen concentration (2.5%, vol/vol) was 10 h. At the same O2 concentration the maximal rates of H2+O2 uptake were reached. The distribution of hydrogenase activity among soluble and particulate protein fractions revealed that the hydrogenase ofAzospirillum strain CC is a membrane-bound enzyme. It showed cross-reaction with antibodies raised against the membrane-bound hydrogenase ofAlcaligenes eutrophus. The hydrogenase in intact cells and crude extracts reacted with methylene blue, phenazine methosulfate, and ferricyanide, but not with NAD or FMN. The specific hydrogenase activity, with methylene blue as an acceptor, was 5.71 U/mg protein in crude extract at 9.38 U/mg protein in the membrane suspension. Hydrogen evolution from reduced viologen dyes could not be demonstrated. The hydrogenase is oxygen sensitive and can be optimally stabilized by addition of dithionite to H2-gased samples.

Verma, Mukesh

doi: 10.1007/BF01577195pmid: N/A

Digestion of bacteriophage SF6 (ofBacillus subtilis) DNA with restriction endonuclease Pst I generates seven fragments (A-G). These fragments were cloned in pBR322 DNA, and the recombinant clones carrying the lysozyme gene were identified by measuring lysozyme activity. The complete nucleotide sequence of 996 bp fragment D, containing lysozymze gene, was determined. One open reading frame was present at 13 bp, and the termination codons were present at 961 bp. The deduced amino acid sequence of the lysozyme gene was also determined.

Péros, Jean-Pierre; Piombo, Georges; Dumas, Jean-Claude

doi: 10.1007/BF01577196pmid: N/A

Ustilago scitaminea synthesizes specific carbohydrates, mainly erythritol and mannitol, plus smaller quantities of arabitol, inositol, and trehalose. Intensive secretion of erythritol is obtained when the fungus is grown in liquid culture. Glucose, fructose, or sucrose can be used interchangeably as carbon sources by the fungus, sucrose being quickly inverted.

Crowther, Richard; McCarthy, Charlotte

doi: 10.1007/BF01577197pmid: N/A

DNA was extracted from 12 clinical isolates of theMycobacterium avium-M. intracellulare-M. scrofulaceum serocomplex (including serovars 1, 2, 3, 4, 8, 42A, and 43), as well as from nine reference strains of other mycobacterial species. Rapid nitrogen decompression was used to weaken the cells for subsequent DNA extraction by a modified Marmur procedure. The DNA was hydrolyzed with phosphodiesterase, and the concentration of released deoxyribonucleotides was determined by reversed-phase high-performance liquid chromatography. The data were used to calculate the mole percentage guanine plus cytosine. Values ranged from 58.6 forM. leprae to 71.5 forM. avium serovar 3. The lowest value for theM. avium-M. intracellulare-M. scrofulaceum serocomplex was 66.3 forM. scrofulaceum serovar 42A. The data indicate that there is greater genetic variability for this group of organisms than is suggested by diagnostic clinical tests and seroagglutination reactions.

Ruiz-Bravo, Alfonso; Jimenez-Valera, María; Cienfuegos, Gerardo; Kouwatli, Khalil; Ramos-Cormenzana, Alberto

doi: 10.1007/BF01577198pmid: N/A

Twelve strains ofYersinia enterocolitica were examined for their ability to bind spontaneously to murine leukocytes. Each of eight HeLa cell invasive strains exhibited nonselective binding to peritoneal leukocytes, lymph node leukocytes, and thymocytes, whereas four noninvasive strains lacked binding properties. Like the HeLa cell invasion, the binding ofY. enterocolitica to leukocytes was much less efficient for bacteria grown at 37°C than for bacteria grown at 22°C. The binding properties were not influenced by the virulence plasmid that codes for Vwa+ phenotype. This leukocyte binding test is proposed as a simple assay for invasive properties ofY. enterocolitica.

Elharrif, Zoubida; Mégraud, Francis

doi: 10.1007/BF01577199pmid: N/A

The enzymatic profiles of 234 wild strains of thermophilic Campylobacters, seven type strains ofCampylobacter species, and 18 reference strains ofCampylobacter species and Campylobacter-like organisms were studied by use of API strips. These strips allow the detection of 56 arylamidases, one transpeptidase, and ten esterases.

Kolstø Otnaess, Anne-Brit; Laegreid, Astrid

doi: 10.1007/BF01577200pmid: N/A

After separation of gangliosides by thin-layer chromatography, femtomolar quantities of GM1 were detected by incubating the plate with native choleratoxin, followed by anticholeratoxin and species-specific labeled antiserum. Only stable reagents were involved when antiserum labeled with horseradish peroxidase was used. Native choleratoxin rather than iodinelabeled toxin ensured good reproducibility of the method.

Iaconis, Joseph; Rolfe, Rial

doi: 10.1007/BF01577201pmid: N/A

Infant hamsters, four days of age or older, developed aClostridium difficile-associated ileocecitis following clindamycin administration, whereas non-antibiotic-treated infant hamsters and hamsters less than four days old given clindamycin were asymptomatically colonized withC. difficile. The incidence of lethality among clindamycin-treated infant hamsters increased with age of the animals, such that all adult hamsters given clindamycin died within 72 h of treatment. Adult hamsters given clindamycin had significantly higher titers of cytotoxin throughout the intestinal tract compared with infant hamsters given clindamycin.

Sepers, Antonie

doi: 10.1007/BF01577202pmid: N/A

The heterotrophic bacterial strain HIS 53 was grown in a continuous culture under chemostat conditions and at sinusoidal or stepwise variations of the dilution rate; aspartate, ammonium, and phosphate were the growth-limiting nutrients. Within a specific nutrient limitation the growth yield was constant and independent of the applied environmental conditions. Compared with the reference chemostat culture, sinusoidal variations of the dilution rate increased the cellular RNA level by 19%–53% dependent on the growth limitation; stepwise variations caused an increase of the RNA level by 28%–41%. It was hypothesized that under the variable environmental conditions in the natural habitat the physiological potential of the organism is enhanced by some such increase of the cellular RNA level. As a consequence these increased RNA levels influence the competition between heterotrophic bacteria and, as a result, also the composition of the population of heterotrophic bacteria.

Ozawa, Kazuo; Iwahana, Hidenori

doi: 10.1007/BF01577203pmid: N/A

A strain ofBacillus thuringiensis subsp.darmstadiensis (serotype 10), which produces heat-stable exotoxin and delta-endotoxin (Exo+Cry+), was used for curing and conjugation-like transformation experiments. After treatment with sodium dodecyl sulfate, nine independent mutants that lacked exotoxin productivity (Exo−) were obtained. Agarose gel electrophoresis showed that all Exo− strains had lost a plasmid, whose size was 62 megadaltons (Mdal). WhenB. thuringiensis was mated with a streptomycin-resistant (Strr)B. cereus strain, five Exo+Strr transformants that had acquired the 62-Mdal plasmid were isolated. Furthermore, the Cry+ phenotype was consistently associated with the Exo+ phenotype. These results indicate that a transmissible plasmid is involved in production of both heat-stable exotoxin and delta-endotoxin.