Quinolones and coumarins were potent eliminators of chloroplasts from Euglena gracilis. There was a remarkable similarity between antichloroplastic and antibacterial activities of DNA gyrase inhibitors. Quinolones produced 100% chloroplast-free cells in concentrations which do not affect cell viability. Optimal conditions were exponential growth, continuous illumination, and neutral or slightly alkaline pH. Coumarins were more toxic than quinolones. Among the quinolones, ofloxacin was the most potent in eliminating chloroplasts. Among the coumarins, coumermycin A1 was the most potent. New quinolones and coumermycin A1 were able to induce the complete inability of originally green cells to form green colonies after 24 h of drug exposure, while clorobiocin and novobiocin required several days of exposure. Darkness, heat shock (42 degrees C, 10 min), or simultaneous treatment with chloramphenicol or rifampin decreased the potency of DNA gyrase inhibitors for producing chloroplast-free cells. Remarkably, in cells in which division was blocked by three different methods (resting medium, hyperthermic conditions [37 degrees C], or addition of cycloheximide), new quinolones and coumermycin A1 nevertheless eliminated chloroplasts. The antichloroplastic activity of DNA gyrase inhibitors is additional data suggesting an evolutionary relationship between chloroplasts and eubacteria.

• MeSH
• 4-chinolony MeSH
• antiinfekční látky farmakologie   MeSH
• chloramfenikol farmakologie   MeSH
• chloroplasty účinky léků   MeSH
• elektronová mikroskopie MeSH
• Euglena gracilis účinky léků   ultrastruktura   MeSH
• inhibitory topoisomerasy II MeSH
• koncentrace vodíkových iontů MeSH
• kumariny farmakologie   MeSH
• rifampin farmakologie   MeSH
• teplota MeSH
• tma MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 4-chinolony MeSH
• antiinfekční látky MeSH
• chloramfenikol MeSH
• inhibitory topoisomerasy II MeSH
• kumariny MeSH
• rifampin MeSH

It is generally assumed that genetic research of mycobacteria is delayed as compared with other, more commonly used, bacterial models, particularly in the field of genetic transfers. In the field of mutagenesis the problems have been studied to such an extent that replication maps of the chromosome of M. phlei and M. tuberculosis H37 Rv have already been constructed and a new model of the cell cycle of bacteria exhibiting a slow growth rate has been worked out. When the problems of mycobacterial genetics are looked upon in the light of gene manipulations it may be concluded that mycobacteria belong to a few models whose genes are used for cloning and that problems of practical significance will be studied by means of the most modern approaches.

• MeSH
• mikrobiální genetika * MeSH
• Mycobacterium genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

A collection of 20 compounds was tested for their ability to induce a permanent loss of chloroplasts from Euglena gracilis cells under conditions increasing the sensitivity of the flagellate to genotoxic compounds, viz. in the resting medium and at an elevated temperature. Streptomycin, dihydrostreptomycin, gentamicin, kanamycin and partially chloramphenicol exhibited mutagenic effects. Eight antibiotics eliminated chloroplasts only from growing cultures and seven antibiotics did not induce the mutation at all.

• MeSH
• antibakteriální látky farmakologie   MeSH
• chloroplasty účinky léků   metabolismus   MeSH
• Euglena gracilis účinky léků   metabolismus   MeSH
• vysoká teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH

The effects of 41 benzothiazolium salts on Euglena gracilis were characterized with regard to the influence on growth and on chlorophyll synthesis, and to their ability to induce permanent loss of chloroplasts. Some salts induced white mutants of E. gracilis (the first benzothiazole derivatives with this activity). The relationship between the biological effect and chemical structure was confirmed and expressed quantitatively by means of Free - Wilson and Fujita - Ban analysis.

• MeSH
• chlorofyl biosyntéza   MeSH
• chloroplasty účinky léků   MeSH
• Euglena gracilis účinky léků   genetika   metabolismus   MeSH
• mutace MeSH
• thiazoly farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chlorofyl MeSH
• thiazoly MeSH

N-Methyl-N-nitrosourea was used to induce auxotrophic, scotochromogenic and isonicotinic acid hydrazide resistant mutants in Mycobacterium phlei and its effect was compared with that of nitrosoguanidine. Seventeen auxotrophic mutants requiring amino acids or vitamins and 52 scotochromogenic mutants with orange colonies were induced. The frequency of isonicotinic acid hydrazide-resistant mutants increased by two orders of magnitude.

• MeSH
• aminokyseliny metabolismus   MeSH
• antibiotická rezistence MeSH
• biologické pigmenty biosyntéza   MeSH
• isoniazid farmakologie   MeSH
• methylnitrosomočovina farmakologie   MeSH
• mutace * MeSH
• Mycobacterium phlei genetika   fyziologie   MeSH
• Mycobacterium genetika   MeSH
• nitrosoguanidiny farmakologie   MeSH
• nitrosomočovinové sloučeniny farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aminokyseliny MeSH
• biologické pigmenty MeSH
• isoniazid MeSH
• methylnitrosomočovina MeSH
• nitrosoguanidiny MeSH
• nitrosomočovinové sloučeniny MeSH