The reaction of an ethanolic solutions of
N-salicylideneglycinatoaquacopper(II) hemihydrate with urea, pyridine, 2,4-dimethylpyridine, 3,5-dimethylpyridine, quinoline, 4-methylquinoline, ...isoquinoline, or 3-methylisoquinoline in an equimolar ratio resulted in solid products containing complexes of the type Cu(salgly)L with distorted square pyramidal coordination polyhedra. The products were characterized by elemental analysis, electronic and EPR spectra, and magnetic susceptibility measurements. Moreover, the crystal and molecular structure of
N-salicylideneglycinatoureacopper(II) dimer was determined by single crystal X-ray diffraction methods. The copper(II) atoms are bridged by two phenolic oxygen atoms with a CuCu distance of 3.1093(11) Å and CuOCu angle of 94.47(12)°. The antimicrobial effects have been tested on various strains of bacteria, yeasts and filamentous fungi.
Marked antimicrobial effects have been found for some new copper(II) complexes derived from
N-salicylideneglycinatoaquacopper(II) hemihydrate parent compound. Tests in vitro were run on various strains of becteria, yeast's and filamentous fungi. The products were characterized by elemental analysis, electronic and EPR spectra, and magnetic susceptibility measurements. The structure of dimeric
N-salicylideneglycinatoureacopper(II) was determined by single-crystal X-ray diffraction methods.
Reaction of an ethanolic solution of N-salicylidene-
l
-glutamatodiaquacopper(II) monohydrate with pyridine, 2-methylpyridine, 4-methylpyridine, 2-aminopyridine, 2,6-diaminopyridine, quinoline, ...2-methylquinoline, 4-methylquinoline or 3-methylisoquinoline resulted in solid products containing complexes of the type Cu(sal-
l
-glu)L with distorted square-pyramidal coordination geometry. The products were characterized by elemental analysis, electronic spectroscopy and magnetic susceptibility measurements. Antimicrobial effects were tested on various strains of bacteria, yeasts and filamentous fungi. To compare the influence of individual ligands (neutral as well as anionic) on their biological activity, copper(II) complexes containing water and a Schiff base derived from salicyldehyde and methyl- and ethyl-esters of
l
-glutamic acid Cu(sal-5-Me-
l
-glu)(H
2
O)
2
and Cu(sal-5-Et-l-glu)(H
2
O)
2
were also prepared and studied. Bioactivities of complexes tested were found to decrease in the sequence bacteria > filamentous fungi > yeasts.
Antifungal activity of new copper(II) complexes of 2-methylthionicotinate (2-MeSNic) of the composition Cu(2-MeSNic)2(MeNia)(2).4H2O (where MeNia is N-methylnicotinamide), and ...Cu(2-MeSNic)2(Nia)(2).2H2O (where Nia is nicotinamide) and Cu(2-MeSNic)2L2 (where L is isonicotinamide, iNia, or ethyl nicotinate, EtNic) were tested on various strains of filamentous fungi by the macrodilution method. Most sensitive against copper(II) adducts with bioactive ligands were Rhizopus oryzae and Microsporum gypseum (IC50 1.5-2.3 mmol/L). The adducts with Nia, MeNia and EtNic at 5 mmol/L induced morphological changes in growing hyphae of Botrytis cinerea, mainly their intensive branching attached to release of cytoplasm with partial growth inhibition. Inhibition of sporulation (> 90%) of Alternaria alternata by Cu(2-MeSNic)2.H2O was observed as a change in the color of the colonies. The highest resistance was marked by B. cinerea and Fusarium moniliforme (average IC50 values 4.25 and 3.13 mmol/L, respectively). The presence of all bioactive ligands in copper(II) complexes caused an increase in the inhibition effect against model fungi (except significant inhibition activity of EtNic on R. oryzae).
The growth and conidiation of the aged Trichoderma viride culture grown in the dark, and after an induction by a light pulse, was examined in the presence of selected mono-, di(tri)saccharides, amino ...acids and alcohols as sole carbon sources. Hexoses and disaccharides, but not pentoses and amino acids, promoted proportionally both growth and conidiation induced by aging or light. All compounds but pentoses promoted the conidiation in aged cultures and photoconidiation in a close correlation. Ethanol, glycerol and ethylene glycol supported both growth and conidiation but these processes were not supported equally. Conidia formation with hexoses and amino acids as sole carbon sources seems to be a function of growth promotion, rather than of growth restriction (starvation, stress, aging). With glucose as sole carbon source the conidiation was not triggered by nutrient limitation, nor by the accumulation of waste metabolites. The aging-induced conidiation can be considered to be triggered by the genetic program of the microorganism rather than by its nutrient status.
Glutamic acid decarboxylase (GAD) activity was measured in homogenates of conidia and both submerged and aerial mycelia of Trichoderma viride. The GAD activity in conidia had a temperature optimum at ...30 degrees C and a pH optimum at pH 4. GAD was stimulated by EDTA (2 mM) and was insensitive to treatment with calmodulin antagonists calmidazolium (10 microM) or phenothiazine neuroleptics (60 microM). Cyclosporin A (up to 300 microM) partially inhibited GAD in the homogenate, but not in the supernatant obtained after centrifuging the homogenate. Attempts to release GAD activity from the homogenate using high ionic strength, detergents, or urea failed. Freezing-thawing led to the partial increase of activity in the conidial homogenate. These results indicate that GAD is a membrane-bound enzyme. The highest specific activity of GAD was present in the mitochondrial/vacuolar organellar fraction. Germination of conidia in the submerged culture led to a temporary decrease in GAD activity. After prolonged cultivation, the activity displayed quasi-oscillatory changes. The stationary state was characterized by a high GAD activity. The presence of gamma-aminobutyric acid in the submerged mycelia was demonstrated. In surface culture in the dark, GAD activity increased in a monophasic manner until conidia formation. The illumination of dark-cultivated mycelia by a white-light pulse caused a dramatic increase in GAD activity. Light-induced changes were not observed in mutants with delayed onset of conidiation. In the dark or upon illumination by light pulse, the increase of GAD activity preceded the appearance of conidia. Thus, GAD activity in T. viride is closely associated with its developmental status and may represent a link between differentiation events and energy metabolism.
Trichoderma viride was capable of growth and conidiation in the presence of high concentrations of the uncoupler 3,3′,4′,5-tetrachlorosalicylanilide (up to 100 µmol·L
-1
) and of the respiration ...inhibitor mucidin (up to 100 µmol·L
-1
) in both submerged and surface cultivation. When vegetative mycelia were cultivated on the solid Czapek-Dox medium with yeast autolysate under an anaerobic and CO
2
-containing atmosphere, the growth was observed only rarely but the microorganism survived as long as 3 months under these conditions. Major products of metabolism of both aerobic and anaerobic submerged mycelia were identified by means of
1
H-NMR measurements. Major products excreted to the medium under aerobic conditions were succinic and citric acids. Major metabolites present in the submerged mycelia were γ-aminobutyric (and glutamic) acid and alanine. Under anaerobic conditions, citric acid was not excreted into the medium but ethanol appeared. Its production could not be increased upon increasing the sugar concentration. The appearance of secondary metabolites was found to be modified by oxygen availability during the mycelial growth. Results suggest that the vegetative form of T. viride is capable of fermentative metabolism characterized by the production of ethanol and succinate and that the excretion of carboxylic acids is developmentally regulated and modified by oxygen availability.Key words: Trichoderma, mycelia, anaerobiosis, citrate, succinate, ethanol, GABA.
Kojic acid (5-hydroxy-2-hydroxymethyl-4-pyranone) represents an attractive polyfunctional skeleton for development of biologically active compounds. The authors prepared a great variety of kojic acid ...derivatives and selected biological properties have been studied. Thus, kojic acid derivatives are promising compounds that might advantageously be used in human and/or veterinary medicine and also in preparation of new, even more biologically active preparations.
Seeds ofKarwinskia humboldtiana obtained from a 1997 collection in the locality of Villa de García Nuevo (León, Mexico) were contaminated with spores of filamentous fungi, bacteria and yeasts. The ...concentration of microorganisms in unscarified seeds ranged from 3.0×103 to 7.5×103 CFU/g. Predominant were bacterial isolates of the generaAeromonas sp.,Bacillus, andPseudomonas; from filamentous fungi were identifiedAlternaria, Aspergillus niger, Cladosporium sp.,Fusarium sp.,Mucor sp.,Penicillium commune, Trichothecium sp.; from yeastsRhodotorula sp. andSaccharomyces cerevisiae. Seed scarification significantly reduced the microbial contamination. Of the original fungal isolates, only two were identified on scarified seeds,viz. Cladosporium sp. andSaccharomyces cerevisiae; although a relatively high incidence of a unidentifiable ofPenicillium sp. was found, the bacterial spectrum was not altered. Treatment of scarified seeds with Vitavax 200 WP and Pomarsol Forte 80 WP (3 mg/g seeds) augmented germination by 10–19% compared to treated unscarified seeds, and by 16–31% compared to untreated unscarified seeds.
