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961.
962.
Mutagenic pollution of environment is a global and important problem. This includes marine environment. Although many mutagenicity assays have been developed, there are specific problems with testing marine water and sediments for mutagenic contamination. One of them is the fact that most of genetically modified strains used in commonly available microbiological mutagenicity assays, like Escherichia coli or Salmonella, survive relatively poorly in marine waters, especially those of higher salinity. Thus, alternative assays have been developed, in which bacteria occurring naturally in marine habitats are employed. These assays, reviewed in this article, appear to be useful in testing not only marine samples but also can be used in other approaches, which involve detection and estimation of the amount of mutagenic compounds. 相似文献
963.
Beata Cwalina Ludmiła Węglarz Zofia Dzierzewicz Tadeusz Wilczok 《Applied microbiology and biotechnology》1988,28(1):100-102
Summary The leaching activity of five batches of Thiobacillus ferrooxidans, strain F26-77, cultivated under various conditions, towards elemental sulphur, ferrous ions, pyrite, covellite, chalcopyrite and sphalerite was studied. The activities of sulphite oxidase, thiosulphate oxidase and rhodanese were determined in crude, cell-free bacterial extracts. The effectiveness of leaching was directly correlated with the enzymic activity of the cultures. The results suggest that the activities of the enzymes metabolizing sulphur and its inorganic compounds in Thiobacillus ferrooxidans, or bacterial leaching activity on sulphur and sulphides, rather than the rate of oxidation of ferrous ions, should be taken as the criterion of usefulness for the leaching of sulphide minerals. 相似文献
964.
Mitchelson Keith R.; Luczak Beata; Porter Andrew J.R. 《Journal of experimental botany》1994,45(11):1655-1659
A genomic DNA fragment was isolated from the genome of Arabidopsisthaliana via hybridization with bacteriophage M13 protein IIIrepeat element. A 45 bp region of the A. thaliana DNA fragmenthas a repeating 12 bp structure that shows sequence homologyto both the M13 repeat and to a rice minisatellite-like element.Hybridization of digests of A. thaliana genomic DNA with theminisatellite DNA generates a multilocus DNA fingerprint withlow polymorphism. Key words: Minisatellite, M13 repeat element, Arabidopsis thaliana 相似文献
965.
The TYLCV-tolerant tomato line MP-1 is characterized by superior transformation competence 总被引:3,自引:0,他引:3
Barg Rivka; Pilowsky Meir; Shabtai Sara; Carmi Nir; Szechtman Alejandro D.; Dedicova Beata; Salts Yehiam 《Journal of experimental botany》1997,48(11):1919-1923
The tomato line MP-1 excels the cultivars commonly used fortransformation with regard to the speed of regeneration, percentageof transformation and frequency of phenotypically normal transgenicplants. These characteristics, together with its tolerance toTomato Yellow Leaf Curl Virus, make line MP-1 very suitablefor large scale generation of transgenic tomatoes. Key words: Lycopersicon esculentum, transformatioefficient tomato line 相似文献
966.
Genowefa Misztal Beata Paw Janusz S. Skierski Ewa Jagie
o-Wjtowicz 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1999,731(2):341
A new, simple and accurate high-performance liquid chromatography (HPLC) method for the determination of formycin A in plasma is presented. The samples were chromatographed on a LiChrosorb RP-18 column after purification using a Bakerbond SPE column. The mobile phase was methanol–0.067 M phosphate buffer, pH 4.20 (1:4, v/v) containing 0.005 M sodium hexanesulfonate. Azathioprine was applied as an internal standard. UV detection was carried out at 293 nm. The method was tested for linearity (over the range 0.1–9.0 μg/ml). The recovery was 91.89% (mean). The described method has been successfully applied to the quantitative determination of formycin A in plasma and should be useful for clinical and bioavailability investigations. 相似文献
967.
Wojciech Kamysz Beata Mickiewicz Katarzyna Greber Sylwia Rodziewicz‐MotowidŁo 《Journal of peptide science》2007,13(5):327-333
Temporin A (TA) is a small, basic and highly hydrophobic peptide, isolated from the skin of the European red frog, Rana temporaria. The TA (FLPLIGRVLSGIL-NH2) displays a broad spectrum of anti-microbial activity against Gram-positive bacteria and fungi Candida albicans. In this study we investigate the solution structure of two TA retro-analogues, (6-1)(7-13)-TA (GILPLFRVLSGIL-NH2) and retro-TA (LIGSLVRGILPLF-NH2) by using nuclear magnetic resonance (NMR). The 3D solution structure of the analogues was established by using inter-proton distances and vicinal coupling constants in the Simulated Annealing (SA) calculations (XPLOR program). The NMR conformational studies show the existence of the helical structure in the middle part of the (6-1)(7-13)-TA peptide and an unordered structure of the retro-TA analogue under the D3-TFE/H2O (3:7, v/v) conditions. Our investigations have shown that the hydrophobic cluster at N-terminus with the Pro amino acid residue in position 3 or 4, the helical structure and the amphipathic character of the peptide are responsible for the anti-microbial activity of the TA analogues. 相似文献
968.
Stefan Irmler Heike Schäfer Beata Beisert Doris Rauhut & Hélène Berthoud 《FEMS microbiology letters》2009,295(1):67-76
The trans -sulfuration pathways allow the interconversion of cysteine and methionine with the intermediary formation of cystathionine and homocysteine. The genome database of Lactobacillus casei ATCC 334 provides evidence that this species cannot synthesize cysteine from methionine via the trans -sulfuration pathway. However, several L. casei strains use methionine as the sole sulfur source, which implies that these strains can convert methionine to cysteine. Cystathionine synthases and lyases play a crucial role in the trans -sulfuration pathway. By applying proteomic techniques, we have identified a protein in cell-free extracts of L. casei , which showed high homology to a gene product encoded in the genome of Lactobacillus delbrueckii ssp. bulgaricus, Streptococcus thermophilus and Lactobacillus helveticus but not in the genome of L. casei ATCC 334. The presence of the gene was only found in strains able to grow on methionine as the sole sulfur source. Moreover, two gene variants were identified. Both gene variants were cloned and expressed heterologously in Escherichia coli . The recombinant enzymes exhibited cystathionine lyase activity in vitro and also cleaved cysteine, homocysteine and methionine releasing volatile sulfur compounds. 相似文献
969.
Beata Kluczek-Turpeinen Pekka Maijala Marja Tuomela Martin Hofrichter Annele Hatakka 《World journal of microbiology & biotechnology》2005,21(8-9):1603-1609
Summary Paecilomyces inflatus isolated from municipal waste compost was found to have cellulolytic activity in several solid and liquid media. This study
was done to reveal the multifarious effects of municipal waste compost on endoglucanase activity of P. inflatus. The highest enzyme activities under the conditions of solid-state fermentation were measured in authentic compost samples
compared with wood, straw and bran substrates. In surface liquid cultures glucose, cellobiose, xylan, Avicel cellulose, carboxymethylcellulose
(CM-cellulose), starch and citrus pectin were used as carbon sources. All carbon sources supported the growth of P. inflatus. However, only CM-cellulose, cellobiose and pectin noticeably stimulated endoglucanase (EG) activity. Further stimulation
of EG activity was obtained in cultures containing 1% CM-cellulose as a carbon source by supplementation with low-molecular
mass aromatic compounds vanillin, veratric acid and benzoic acid, and with soil humic acid (SHA). SHA and veratric acid were
found to be the most efficient elicitors of the cellulolytic activity. P. inflatus was able to utilize nitrate and ammonium as pure nitrogen sources in media containing cellulose. 相似文献
970.
Presence of five carboxypeptidases was found in endosperm of germinating triticale grains, while two of them in scutellum.
Changes of their activities during four days of germination suggest that carboxypeptidase II plays an important role at initial
stage of germination, while carboxypeptidases I and III - at subsequent stages of the process. High activity of carboxypeptidase
II both in scutellum and endosperm of dry grains accompanied by its decrease during germination, and on the other hand, the
appearance of carboxypeptidases I and III activities at the 2nd and 3rd day of the process seems to confirm such functions of these enzymes. Experiments with GA3 indicated that carboxypeptidase I was synthesized in scutellum, and carboxypeptidase III — in aleurone layer. Carboxypeptidases
I and II cleave N-CBZ-Phe-Ala, and carboxypeptidase III — N-CBZ-Ala-Met and N-CBZ-Ala-Phe as substrates with the highest rate. 相似文献