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1

Optimisation of the microbiological mutagenicity assay based on genetically modified Vibrio harveyi strains

100%
Podgorska B., Chec E., Ulanowska K., Wegrzyn G.
Journal of Applied Genetics
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2005
|
tom 46
|
nr 2
Recently, we have developed a novel assay designed for detection of mutagenic pollution of the marine environment. This assay is based on the use of a series of genetically modified strains (named BB7, BB7M, BB7X and BB7XM) of a marine bacterium Vibrio harveyi. Sensitivity of the V. harveyi mutagenicity assay was found to be similar to, or even somewhat higher than, that of the commonly used Ames test. Subsequent studies indicated that this assay may be useful in assessment of mutagenic contamination of the marine environment. Nevertheless, we assumed that improvement of this assay is still possible, and thus we aimed to optimise its procedures. Here we present our research on the optimisation of the V. harveyi mutagenicity assay, which indicated that different tester strains used in this assay give the best results depending upon the experimental conditions employed. Incubation of bacteria in a buffer, rather than in a nutrient broth, containing a mutagen, increased the efficiency of the assay with BB7 and BB7M strains, but had a deleterious effect in the case of BB7X and BB7XM. The latter couple of strains revealed higher mutagenicity in the plate assay, as compared to the liquid medium assay. However, the opposite effect was observed for BB7 and BB7M. Low-dose (1 J m⁻²) UV irradiation, as well as 30 min incubation in 0.1 M CaCl₂, had no significant effect on the efficiency of the assay when using BB7 and BB7M, whereas the number of mutagen-induced mutants of BB7X and BB7XM strains increased about two times under these conditions. Our previous experiments indicated that various tester strains revealed different sensitivity to particular mutagens. Thus, a series of strains should be used in the assay. Results presented in this report show that different conditions should be used for two pairs of the tester strains: BB7 and BB7M, and BB7X and BB7XM.
2

A novel Vibrio harveyi mutant with altered quorum sensing regulation

100%
Czyz A., Zielke R., Wegrzyn G.
Oceanological and Hydrobiological Studies
|
2005
|
tom 34
|
nr 2
3

Szczepy morskiej bakterii Vibrio harveyi jako potencjalne organizmy testowe w wykrywaniu zanieczyszczen mutagennych w srodowisku morskim.

72%
Szpilewska H.
Działalność Naukowa PAN. Wybrane Zagadnienia
|
2000
|
tom 09
40-41
4

Cloning of the groE operon of the marine bacterium Vibrio harveyi using a lambda vector

72%
Kuchanny D., Klein G., Krzewska J., Czyz A., Lipinska B.
Acta Biochimica Polonica
|
1998
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tom 45
|
nr 1
groES and groEL genes encode two co-operating proteins GroES and GroEL, belonging to a class of chaperone proteins highly conserved during evolution. The GroE chaperones are indispensable for the growth of bacteriophage λ in Escherichia coli cells. In order to clone the groEL and groES genes of the marine bacterium Vibrio harveyi, we constructed the V. harveyi genomic library in the λEMBL1 vector, and selected clones which were able to complement mutations in both groE genes of E. coli for bacteriophage λ growth. Using Southern hybridization, in one of these clones we identified a DNA fragment homologous to the E. coli groE region. Analysis of the nucleotide sequence of this fragment showed that the cloned region contained a sequence in 71.7% homologous to the 3' end of the groEL gene of E. coli. This confirmed that the λ clone indeed carries the groE region of V. harveyi. The positive result of our strategy of cloning with the use of the genomic library in λ vector suggests that the same method might be useful in the isolation of the groE homologues from other bacteria. The V. harveyi cloned groE genes did not suppress thermosensitivity of the E. coli groE mutants.
5

Mutagenic activity of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

72%
Ulanowska K., Wegrzyn G.
Journal of Applied Genetics
|
2006
|
tom 47
|
nr 1
MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) is a neurotoxin, which can damage dopaminergic neurons. It causes symptoms resembling those observed in patients suffering from Parkinson’s disease, and hence this toxin is widely used in studies on animal models of this disorder. Mutagenicity of MPTP was also reported by some authors, but results obtained by others suggested that this compound is not mutagenic. Interestingly, those contrasting results were based on the same assay (the Ames test). Therefore, we aimed to test MPTP mutagenicity by employing a recently developed Vibrio harveyi assay, which was demonstrated previously to be more sensitive than the Ames test, at least for some mutagens. We found that MPTP showed a significant mutagenic activity. Moreover, MPTP mutagenicity was attenuated by methylxanthines, compounds that are known to form complexes with aromatic mutagens.
6

Methylxanthines [caffeine, pentoxifylline and theophylline] decrease the mutagenic effect of daunomycin, doxorubicin and mitoxantrone

72%
Piosik J., Gwizdek-Wisniewska A., Ulanowska K., Ochocinski J., Czyz A., Wegrzyn G.
Acta Biochimica Polonica
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2005
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tom 52
|
nr 4
Previously performed experiments showed that methylxanthines, especially caffeine, may protect cells against cytostatic or cytotoxic effects of several aromatic compounds. One of the proposed mechanisms of this protection is based on stacking interactions between π electron systems of polycyclic aromatic molecules. In this work, we demonstrate that caffeine and other methylxanthines  -  pentoxifylline and theophylline - significantly decrease mutagenicity of the anticancer aromatic drugs daunomycin, doxorubicin and mitoxantrone. The spectrophotometric titration of these aromatic compounds by methylxanthines indicated formation of mixed aggregates. The concentrations of free active forms of the drugs decreased when the concentrations of methylxanthines increased in the mixture. Therefore, likely methylxanthines may play a role of scavengers of the free active forms of daunomycin, doxorubicin and mitoxantrone.
7

Inhibition of luminous Vibrio harveyi by "green water" obtained from tank culture of tilapia, Oreochromis mossambicus

58%
Huervana F. H., De La Cruz J. J. Y., Caipang C. M. A.
Acta Ichthyologica et Piscatoria
|
2006
|
tom 36
|
nr 1
Background. Luminous vibriosis caused by Vibrio harveyi, is a serious disease problem in shrimp aquaculture. The use of "green water", a technique that involves the stocking of tilapia, Oreochromis in the reservoir for the production of green microalgae, Chlorella is believed to help in the reduction of the incidence of luminous vibriosis. Though most shrimp farmers have been using Mozambique tilapia, Oreochromis mossambicus for the production of "green water", the mechanism involved in the efficiency of using this fish species in reducing luminous vibriosis remains unknown and is largely based on speculations. It was for this reason that the present experiment was conducted. The aim of the study was to determine the antibacterial activity of "green water" obtained from tank culture of Oreochromis mossambicus against Vibrio harveyi under laboratory conditions. Materials and Methods. "Green water" collected from broodstock and juvenile tanks of Oreochromis mossambicus as well as water from a commercial shrimp pond, and filtered boiled seawater were inoculated with Vibrio harveyi. Luminous bacteria were counted in nutrient agar, while presumptive and green colony-forming vibrios were determined on thiosulfate-citrate bile salt (TCBS). The experiment was carried out for one week. Results. Luminous bacteria were not detected, and the presumptive and the green colony-forming vibrios were generally lowest in "green water" obtained from the broodstock tank. Luminous bacteria in "green water" obtained from juvenile tank were not detected starting day 5, indicating delayed inhibition. Conclusion. The present findings show that "green water" from broodstock tank of O. mossambicus has the ability to inhibit luminous vibriosis over a one-week period, and that broodstock are a better source of "green water" than juveniles in controlling luminous vibriosis.
8

Bioluminescencja cz.1 - żywe światła

44%
Suchorska M., Dudzinska-Bajorek B.
Ekonatura
|
2012
|
nr 11
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