Induction of cellulase in trichoderma reesei grown on lactose

Intracellular concentrations of ATP, cyclic AMP and glucose-6-phosphate were monitored during growth of partially catabolically derepressed strain of Trichoderma reesei CC II in medium containing lactose as the sole carbon source. The induction of cellulase synthesis occured when the concentration of lactose in the medium decreased below 7 mg/ml. The onset of cellulase synthesis was preceded by a transient peak of intracellular concentration of ATP and by the increase of the cyclic AMP contents in the mycelium whereby the intracellular level of glucose-6-phosphate was at its minimum. By keeping the lactose concentration in the medium at 2 mg/ml, it was possible to support the continuation of cellulase synthesis over the prolonged periods without appreciable growth of biomass.     

Antibiotics and apochlorosis

Twenty-four out of 38 5-nitrofuran derivatives caused bleaching ofEuglena gracilis similar to that produced by streptomycin, erythromycin and other antibiotics. Derivatives with electron-donor substituents in thep-position of the benzene nucleus attached to position 2 of benzimidazole displayed the greatest bleaching activity. The addition of hydroxylamine to a growingEuglena gracilis culture together with a 5-nitrofuran interfered with the latter's bleaching effect. The mechanism of the effect of 5-nitrofurans on theEuglena gracilis chloroplast system is thus probably identical with the mechanism of the effect of streptomycin and erythromycin. A certain correlation was observed between the bleaching effect and the antibacterial activity of the various 5-nitrofurans tested.     

Changes of 3,4-dihydroxybenzoic and 4-hydroxybenzoic acids inNicotiana tabacum cell suspension culture

The optimum conditions for cell suspension culture experiments have been characterized by respiration,p-Phenylenediamine oxidase and growth of cell suspension ofNicotiana tabacum for 15 days in stationary culture. Change of 3,4-Dihydroxybenzoic and 4-Hydroxybenzoic acids both present at 10⁻⁴ M in culture medium were studied in short term experiments. An oxidation product of 3,4-Dihydroxybenzoic acid characterized by an absorption maximum at 280 nm was isolated after 1 h of incubation. The 4-Hydroxybenzoic acid did not change when incubated for 4 h under the same conditions.     

Transport systems for acyclic polyols and monosaccharides inTorulopsis candida

The yeastTorulopsis candida NCYC 576 was found to transport acyclic polyols (D-arabinitol,L-arabinitol, ribitol, xylitol,D-mannitol,D-glucitol and erythritol) and monosaccharides (D-galactose,L-sorboseD-xylose) by an active process, reaching high intracellular concentrations, making use of four different carrier systems: (1) high-affinity for polyols, (2) high-affinity for monosaccharides, (3) lowaffinity for both polyols and monosaccharides, and (4) specific high-affinity for erythritol andD-ribose.     

Floral meristems as a source of enhanced yield and quality of DNA in grasses

Floral meristems of Lolium and Festuca grasses give a 5- to 19-fold enhancement in yield of extracted DNA in comparison with leaves. Meristems also provide highly pure DNA samples. The method could be useful for applications in molecular genetics in many species of the Gramineae. Received: 14 April 1998 / Revision received: 8 June 1998 / Accepted: 10 July 1998     

DNA synthesis byLactobacillus acidophilus during glutamic acid starvation

The synthesis of DNA was investigated inLactobacillus acidophilus R-26 during starvation for glutamic acid. The synthesis of RNA and of proteins was also examined. The content of DNA in the cell increased by 150–250%. The results show that new DNA-replication cycles can be initiated without simultaneous synthesis of proteins and of RNA.     

Variation in size of the dragonefly m-chromosome,with considerations on its significance for the chorogeography and taxonomy of the order odonata,and notes on the validity of the rule of reinig

The morphological and kinetical features of the so-called m-chromosomes in dragonflies are reviewed. The relative size of the m-chromosomes varies in some species, but not in all. It has been demonstrated that the size is peculiar, in some dragonflies, for populations originating from different portions of the species range, and therefore it could be used to advantage in the taxonomy of infraspecific forms. The dragonfly m-chromosomes are considered as fragments of normal autosomes. The break can take place at any time, at any place in the holokinetic chromosome, and in any geographic population, therefore the variation in size of the m-chromosome is only accidental and has no chorogeographic implications. The chorogeographic hypothesis ofReinig (1938, 1939), which has been widely promoted by some distinguished odonatologists, has no connection with the size trend of the m-chromosomes. Its general validity for the determination of the body size of dragonflies is likewise rejected. Paper presented at the Meeting of the Genetical Society of the Netherlands, 28 November 1967, Utrecht. This paper is the third report on the research project supported by grant No. 913-19 of the Netherlands Organization for the Advancement of Pure Research (Z.WW. O.).