Molecular biology of photosynthesis

Book reviews

Molecular biology of photosynthesisGovindjee, H.J. Bohnert, W. Bottomley, D.A. Bryant, J.E. Mullet, W.L. Ogren, H. Pakrasi, and C.R. Somerville (Eds.), Dordrecht: Kluwer Academic Publishers, 1989. xxvii + 815 pages. £130.00. ISBN 0-7923-0097-1     

Autoradiographic study of the effect of 5-Fluorodeoxyuridine on barley chromosomes

FUdR 10^?4 M was applied together with [³H] TdR on the growing barley embryos cultivated in the nutrient solution. Samples were fixed 1–4 h after the onset of the treatment and microautoradiograms were prepared. All the mitoses were unlabelled, while more than 150 autoradiographic grains were found above labelled interphase nuclei; no cells that terminated S phase at the onset of the treatment passed through entire G₂ and reached mitosis during the 4 h duration of the treatment. Chromosomal fragments in anaphases appeared the first hour after the onset of the treatment. Their frequency increased from the first to the second hour and remained almost constant from the second to the fourth hour. FUdR induces chromosomal fragments in barley root meristems also in G₂ phase of the mitotic cycle.     

Comparison of seed proteins of some representatives of the genusPisum from the point of view of their relationship comparison by disc electrophoresis

Ten taxa of the genusPisum were examined by disc electrophoresis in gels according to Davis and to Reisfeldet al. For evaluation of band patterns the Jaccard Index was applied. The results in both types of gels show thatPisum abyssinicum and especiallyP. fulvum have biochemically a relatively isolated position.Pisum elatius and its subspeciescaspicum andpalestinicum form a subgroup withP. cinereum;P. sativum var.zeylanicum and cv. Jupiter form another subgroup withP. syriacum. Our results are in good agreement with the results of Przybylskaet al. (with the exception ofP. cinereum) and also with immunoelectrophoretic analyses performed by Turkováet al. (1980), with the same exception.     

Effect of cultivation conditions on the activity of the beromycin producerStreptomyces glomeratus 3980 and its spontaneous variants

Optimal conditions for the submerged cultivation ofStreptomyces glomeratus 3980, producer of the anthracycline antibiotics beromycins, and its variants were sought in media with glucose, soybean meal and salts differing in the content of ammonium sulphate. As compared with the original activity of the strain the antibiotic titre of some variants increased about 12 times on increasing the glucose concentration from 3 to 5 %, or on omitting CaCO₃ from the medium (i.e. under conditions leading to an increased production of propionic acid and suppression of production of the melanin-like pigment). In melanin-less variants accumulating propionate even under standard conditions the activity increased about 18–40 times in the medium with 3 % glucose and 0.2 % CaCO₃ under conditions of more intensive aeration (i.e. under conditions when no propionic acid accumulated). Individual strains also differed in the requirement for (NH₄)₂SO₄ in the medium, their response to changes of volume of the vegetative inoculum and sensitivity to MgSO₄.7H₂O. The biosyiithetic activity of all strains was inhibited by the addition of ZnSO₄.7H₂O or CaCl₂ and substitution of glucose with starch, lactose or sucrose.     

The occurrence of C28 sterols in red algae

Lenormandia prolifera and Amansia glomerata contain large amounts of 24-methylenecholesterol. These two algae belong to the Amansia group of Rhodomelaceae as do Rytiphloea tinctoria and Vidalia volubilis, which are already known to be able to alkylate sterols at C-24. Halopythis pinastroides is an exception in the Amansia group, no C-28 sterols being present in this alga.     

Sporulation-inducing factor inStreptomyces avermitilis

The excretion of a diffusible factor was detected in sporulating, avermectin-producing strain ofStreptomyces avermitilis. The factor induced the formation of aerial mycelium and spores by a nonsporulating mutant.     

Quantification of airborne microorganisms and investigation of their interactions with non-living particles

A fluorescence method was developed for the direct counting of airborne microorganisms and for the examination of their interactions with other aerosol particles. The method is based on a combination of the aerosol sampling technique using a cascade impactor and the selective dyeing of the trapped microorganisms with ethidium bromide. The method enables both the total microorganism concentrations and their counts in clusters to be evaluated. The new method and the cultivation method, enabling the colony-forming units (CFU) to be determined, were compared. Based on the results obtained by the fluorescence technique, a procedure is suggested for the conversion of CFU data to bacteria and yeast concentrations.     

Foliikole Flechten aus Tanzania (Ost-Afrika)

In einer umfangreichen Kollektion foliikoler Flechten gesammelt von Dr.T. Pócs in Tanzania wurden 107 Arten festgestellt. Von diesen wurden 20 Arten und 2 Varietäten als neu beschrieben. Ein neuer Typus von „Isidia scutelliformia”, ein morphologisch ungewöhnlicher Pyknidium-Typus und ein komplizierter konidientragender Fruchtkörper wurden auch beschrieben. Ein Bestimmungschlüssel der afrikanischen foliikolenBacidia-Arten und Bermerkungen für die Umgrenzung der FamilieMegalosporaceae (ad interim) sind angeführt.