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141.
Jan Nešvera Jitka Hochmannová Miroslav Pátek Alena Šroglová Věra Bečvářová 《Applied microbiology and biotechnology》1994,40(6):864-866
Gram-positive facultative methylotrophic coryneform bacterium Brevibacterium methylicum was efficiently transformed with various plasmids using electroporation of intact cells. In addition to the plasmid vectors pEC71 and pZ6-1 constructed on the basis of cryptic plasmids from coryneform bacteria, broad-host-range plasmids pLS5 (derivative of plasmid pMV158 from Streptococcus agalactiae) and RSF1010 belonging to the incompatibility group IncQ from Gram-negative bacteria were found to be present as autonomous structurally unchanged DNA molecules in B. methylicum transformants. With the exception of pZ6-1, all these plasmids were stably maintained in B. methylicum cells grown under non-selective conditions. When plasmid DNAs isolated from B. methylicum were used, the highest efficiency of transformation (105 transformants/g DNA) was achieved.
Correspondence to: J. Nevera 相似文献
142.
G. Sekaninová M. Hofer I. Rychlík J. Pillich M. Kolářová V. Zajícová D. Kubíčková 《Folia microbiologica》1994,39(5):381-386
A new bacteriophage typing set, composed of 22 phages, was established as a tool for differentiation ofProteus strains. All the phages were tailed and included 4 morphological types (A1, A2, B1 and C1). They were classified into the
familiesMyoviridae, Siphoviridae andPodoviridae. From the set, 19 phages had double-stranded DNA and 3 were single-stranded DNA phages. 相似文献
143.
Cells ofBacillus megaterium contain 35–45% of poly(3-hydroxybutyrate) (PHB) at the beginning of the stationary phase. This amount is only slightly affected
by the medium composition. The PHB granules are spherical with the mean diameter of 1.15 μm. 相似文献
144.
Manganese peroxidase as an extracellular enzyme is produced by the white rot fungusPhanerochœte chrysosporium under nutrient nitrogen or carbon limitation. The effect of nitrogen concentration on the activity of manganese peroxidase
was studied using ammonium nitrate andl-asparagine as nitrogen sources. The highest activity of the enzyme was observed in cultures grown in a medium containing
75 mg/L ammonium nitrate and 0.15 g/Ll-asparagine. Manganese peroxidase was not detectable in cultures grown in the presence 0.5 g/L ammonium nitrate and 1 g/Ll-asparagine. 相似文献
145.
Vanadium was determined by radiochemical neutron activation analysis (RNAA) with proven accuracy in urine of workers occupationally
exposed to vanadium-rich dust in a vanadium pentoxide production plant, and values in the range of 3.02–762 ng/mL (median
33.0 ng/mL) were found. In a control group consisting of administrative workers of the plant, urinary vanadium levels were
found in the range of 1.05–53.4 ng/mL (median 2.53 ng/mL), whereas in an another control group of occupationally nonexposed
persons, these values amounted to 0.066–0.489 ng/mL (median 0.212 ng/mL).
Accuracy of the results was tested by analysis of reference material IAEA A-13 Animal Blood and NIST SRM-1515 Apple Leaves,
and very good agreement was found with literature and the NIST certified values, respectively. Unlike urine, no significant
differences were found for cystine levels in fingernails and hair of exposed and control persons. 相似文献
146.
Summary
Mortierella alpina S-17 cultivated in shaker flasks in the semisynthetic liquid medium with 3% glucose at 28 °C for 14 days accumulated 2.1 g/l of intracellular lipid rich in arachidonic acid (ARA). The content of ARA was 50 % of the total fatty acids. The simple method for high pure methyl arachidonate preparation was developed. 相似文献
147.
Lydiya I. Sergeeva Ivana Macháčková Tatyana N. Konstantinova Svetlana A. Golyanovskaya Josef Eder Oksana O. Zaltsman Jan Hanuš Nina P. Aksenova 《Journal of Plant Growth Regulation》1994,13(3):147-152
The levels of endogenous IAA and cytokinins (zeatin, zeatin riboside, isopentenyladenine, and isopentenyladenosine) were determined in potato plants cultured in vitro under red light (R) and blue light (B) on medium with or without hormones. On medium without hormones in B, plants contained much higher cytokinin levels, particularly in leaves and roots, and also slightly elevated IAA levels. Kinetin in the medium in B changed the distribution of cytokinins and significantly increased IAA level in roots. In R, the presence of kinetin led to an increased cytokinin level in the whole plant, while the IAA level was slightly lower. IAA in the medium in B decreased cytokinin level in all plant parts, while the IAA level did not change significantly. In R, the presence of IAA in the medium led to a moderate increase of CK level and to a significant increase in IAA level, especially in roots. Uptake of 1-14C-IAA and of 3H-zeatin was generally higher in B than in R. Higher percentage of IAA taken up in B was converted to conjugates in the roots. Metabolism of 3H-zeatin was similar in R and B with only slight differences in metabolite amounts.Thus, in all experimental situations in which tuber formation was stimulated, IAA level in roots and stolons rose significantly, stressing the importance of an IAA gradient for tuber formation. 相似文献
148.
Matjana Didek-Brumec Vladimira Gaberc-Porekar Marija Alačević Helena Sočič 《Applied microbiology and biotechnology》1993,38(6):746-749
Protoplasts of morphologically and biochemically different Claviceps purpurea strains producing ergotoxins were fused without introducing selective auxotrophic markers. Fused strains thus obtained differed significantly in biosynthetic activity and morphology from the prototrophic isolates obtained after fusion of the same parent strains marked by auxotrophy. Comparison of the two types of fused strains showed about tenfold higher alkaloid production in fusants obtained from prototrophic strains. Selected stable prototrophic isolates also showed a significant productivity improvement in comparison with the original parent strains.
Correspondence to: M. Didek-Brumec 相似文献
149.
Summary Ubiquinone-10 (Q10) production was measured in batch cultures of Paracoccus denitrificans grown for 8 h at increasing oxygen concentrations (0–21 % O2 in the sparging gas). Whereas the cellular level of Q10 decreased monotonically from 1.2 to 0.5 mol/g d.w., the total yield of Q10 was maximal at 2.5 % O2 and amounted to 350 nmol (0.3 mg) per L of culture. 相似文献
150.