Antibacterial effect of substituted 4-quinazolylhydrazines and their arylhydrazones determined by a modified microdilution method

Eight 4-quinazolylhydrazines and eleven their arylhydrazones have been tested for antibacterial effects and for structure-activity relationships by a modifed microdilution method. The derivative 6-chloro-2-morpholino-4-quinazolyl-5′-nitro-2′-furylhydrazone had the highest antibacterial effect, the MIC values being 100 mg/L forE. fœcalis, 250 mg/L forS. aureus, 200 mg/L forP. aeruginosa and 350 mg/L forE. coli. The most effective derivatives were those with the benzene ring substituted with chlorine or methyl group in position 6 or 8 and with pyrimidine ring substituted with a secondary amine in position 2. The modified microdilution method did not give rise to any statistically significant deviations in the MIC values for ampicillin in comparison with reported reference collection values. Dedicated to Professor Vladimír Betina, DSc. on the occasion of his 65th birthday     

Antimicrobial effects of the macrocyclic Cu(II)-tetraanhydroaminobenzaldehyde complex

The Cu(II)-tetraaza macrocyclic complex exhibited antimicrobial effects on bacteria, yeasts and filamentous fungi. The highest antibacterial activity was found withB. subtilis andS. aureus, the respective IC₅₀ values being 18 and 80 μg/L and the MIC values 50 and 1000 μg/L. A concentration of 1 mg/L exerted a bacteriocide effect onS. aureus. The MIC value forB. subtilis was 250 times lower and forP. aeruginosa 10 times lower than the corresponding values for ampicillin. The Cu-complex was inactive against all tested yeasts. The strongest antifungal effect was manifested forR. nigricans, with an IC₅₀ value under 0.1 mg/L, whereas inA. alternata the IC₅₀ was 13.5 mg/L.     

Antibacterial and mutagenic activities of new isothiocyanate derivatives

Nine newly synthetized isothiocyanate derivatives were demonstrated to posses antibacterial and genotoxic activitiesin vitro. 4-Hydroxybutyl isothiocyanate exhibited a broad antibacterial effect, with MIC values of 762 μmol/L forStaphylococcus aureus andEscherichia coli. Ethyl 4-methylsulfoxidobutanoate had the highest antibacterial activity in Gram-positive bacteria, the MIC value being 425 μmol/L forS. aureus. The highest tested concentrations of ethyl 4-isothiocyanatobutanoate and 4-hydroxybutyl isothiocyanate produced a bacteriocidal effect in Gram-positive bacteria. The compounds showed no mutagenic effects onSalmonella typhimurium tester strains TA 98 and TA 100, either in the absence or in the presence of a metabolically active microsomal S9 fraction from rat liver using standard Ames test.     

Attachment of lactic acid bacteria to beef-muscle surfaces

The effect of immersion time and cell concentration in the attachment of several lactic acid bacteria with antibacterial activity to beef-muscle surface was studied. The number of firmly attached bacteria increased with immersion time in the case ofPediococcus acidilacti, Lactobacillus sake, Lactococcus cremoris (two strains) andPediococcus acidilacti. Pediococcus pentosaceus, Lactococcus lactis andLactobacillus curvatus reached maximum adhesion after 15–30 min. The highest strength of attachment (Sr values) were observed after 15–30 min of contact, time except forP. pentosaceus. For all strains, the number of bacteria adhering to meat increased with increasing cell concentration in the adhesion medium. The highest strength of attachment was observed at a cell concentration of 10⁵/mL mainly forL. sake, L. lactis andL. cremoris. Due to their attachment characteristics,L. sake, L. lactis andL. cremoris are proposed as potential biocontrol agents because they could grow on meat surface and limit the potential attachment of pathogenic microorganisms.     

A survey of C-band patterns in chromosomes ofLilium (Liliaceae)

C-band patterns are described for 20Lilium spp. distributed across six sections. All species have a similar basic karyotype (n = 12) but C-bands differ markedly between them. The patterns are characterized by a dispersed scattering of thin intercalary bands as well as centric and NOR bands. Only one species,L. canadense, shows a clear equilocal pattern with intercalary C-bands occurring proximally in all of the longer chromosome arms. Comparing species, similar patterns are revealed forL. regale andL. sulphureum, forL. formosanum andL. longiflorum (all in sect.Leucolirion) and to a lesser extent forL. hansonii, L. martagon, andL. tsingtauense (sect.Martagon). The pattern forL. henryi (previously classed in sect.Sinomartagon) matches those ofL. regale andL. sulphureum quite well and its transfer to sect.Leucolirion is proposed. This is consistent with results from interspecies hybrids betweenL. henryi andL. regale (and related species) which are reportedly fertile. No other clear similarities in C-band patterns were seen across species. It seems that C-band patterns change rapidly inLilium and hence their usefulness in classification will be restricted to identifying closely related species.Dedicated to Prof.D. G. Catcheside on the 80th anniversary of his birth.     

Quantitative determination by real-time PCR of four vaginalLactobacillus species,Gardnerella vaginalisandAtopobium vaginaeindicates an inverse relationship betweenL. gasseriandL. iners

Background  

Most studies of the vaginal microflora have been based on culture or on qualitative molecular techniques. Here we applied existing real-time PCR formats forLactobacillus crispatus,L. gasseriandGardnerella vaginalisand developed new formats forAtopobium vaginae,L. inersandL. jenseniito obtain a quantitative non culture-based determination of these species in 71 vaginal samples from 32 pregnant and 28 non-pregnant women aged between 18 and 45 years.     

Production of antibacterial violet pigment by psychrotropic bacterium RT102 strain

The antibacterial action of violet pigment, a mixture of violacein and deoxyviolacein, isolated from phychrotrophic bacterium RT102 strain was examined, and the operational conditions for the effective production of violet pigment were studied. The antibacterial activity of the violet pigment was confirmed for several bacteria such asBacillus licheniformis, Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, andPseudomonas aeruginosa, and the high concentration of violet pigment, above about 15 mg/L, caused not only growth inhibition but also death of cells. The growth properties of RT102 strain were clarified under various incubation conditions such as pH, temperature, and dissolved oxygen concentration. The maximum violet pigment concentration,i.e. 3.7 g/L, and the maximum productivity of violet pigment,i.e. 0.12 g L⁻¹h⁻¹, were obtained in a batch culture of pH 6, 20°C, and 1 mg/L of dissolved oxygen concentration.     

A preliminary study of production of antimicrobial substances byPenicillium purpurogenum

A new modified medium favourable forPenicillium purpurogenum Stoll. to produce antibacterial and antifungal compounds was designed. Maximum antibacterial activity was reached in it after 12 days at 30°C.Staphylococcus aureus F DA 209 P,Pseudomonas pyocyanea, Mycobacterium phlei andCladosporium cucumerinum were the most sensitive organisms.     

Predatory mirids of the green apple aphidAphis pomi,the two-spotted spider miteTetranychus urticae and the European red mitePanonychus ULMI in apple orchards in Québec

The incidence of predation of eight species of predacious mirids (Hemiptera: Miridae) present in an apple orchard of Québec on the green apple aphid, two-spotted spider mite and European red mite were investigated. The daily consumption rates varied from 1–2 green apple aphids forHyaliodes vitripennis Say andCampylomma verbasci Meyer to 7–9 aphids forDeraeocoris fasciolus Knight andLepidopsallus minisculus Knight.H. vitripennis consumed significantly more mites than the other mirid species with 26 and 18 mites per day for the two-spotted spider mite and the European red mite respectively. The combined use ofH. vitripennis andL. minisculus is suggested for the control of phytophagous mites. This paper is contribution No. 335/91.06.02R, Research Station, Agriculture Canada, Saint-Jean-sur-Richelieu, Québec, Canada.     

Lupinus species differ in their requirements for iron

The effect of iron supply on the growth and nodulation ofLupinus angustifolius L. (Gungurru),Lupinus luteus L. (R-1171) andLupinus pilosus Murr. (P20957) was studied in acid solutions. Plants of the three species were grown together in the same solution and inoculated withBradyrhizobium (Lupinus) WU 425. Plants were then grown with or without applied NH₄NO₃. The lupin species differed greatly in their sensitivity to low iron concentrations in solution withL. pilosus being most tolerant andL. luteus most sensitive.L. pilosus had the highest iron concentration in tissues and had a higher ratio of iron concentration in the youngest fully expanded leaf blades (YEB) to that in roots than the other two species.L. luteus had higher iron concentrations in roots but lower iron concentration in YEB and shoots than didL. angustifolius. The requirements of internal iron for the maximal chlorophyll synthesis in YEB were 65 μg g^-1 forL. angustifolius andL. luteus, and 52 μg g^-1 forL. pilosus. In contrast to effects on growth, the three species had similar external iron requirements for nodule formation in roots and for maximal nitrogen concentrations in shoots. The results indicate that iron tolerant lupin species require lower internal and external iron supply and have a greater ability than sensitive species to translocate iron from roots to shoots.     

A meat-based diet for rearing the predatory stinkbugsPodisus maculiventris andPodisus sagitta [Het.: Pentatomidae]

A diet based on bovine meat was evaluated as an alternative food source for rearing the predatory bugsPodisus maculiventris (Say) andPodisus sagitta (Fabricius). Thus far, 7 and 5 continuous generations of the respective species have been reared on this diet. In comparison to rearing on larvae of the greater wax moth,Galleria mellonella (L.), however, nymphal development was prolonged with 15–40% and adult weights were lower, reaching 72–82% of the control weights. Fecundity of females reared on the meat diet was reduced to about 1/3–1/2 of that of the control, but egg weight and egg fertility were comparable with those in cultures fed live prey. Results obtained for laboratory rearing on this medium were generally better forP. maculiventris than forP. sagitta.      

TheLecanactis grumulosa group (Opegraphaceae) in the Mediterranean region

The morphology, anatomy, and chemistry of five taxa belonging to theLecanactis grumulosa group from several localities of the Mediterranean area have been analysed in detail. One new saxicolous species,L. subgrumulosa, is described from Spain and Morocco. The new combinationL. farinosa is made.L. nothiza, L. monstrosa, L. ramosus, andOpegrapha alboatra are proposed as synonyms ofL. grumulosa. L. werneri andL. farinosa are cited for the first time in Europe and northern Africa, respectively. Anthraquinones are reported as new forLecanactis.     

Effect of structure on antibiotic action of new 9-(ethylthio)acridines

Six new 9-(ethylthio)acridine derivatives were examined for antibacterial and antifungal activities with 10 bacterial and 8 yeast strains. The only active compounds were 2-and 3-amino derivatives. The observed MICs (mg/L) for 2-amino-9-(ethylthio)acridine (possessing the highest biological activity) were 12 (P. mirabilis), 30 (B. subtillis), 60 (C. freundii), 90 (E. coli), 128 (E. vulneris) and 500 (S. marcescens andS. aureus). Both amino derivatives have also lowest half-wave potential (E _1/2) and field Swain-Lupton constants (describing oxidoreduction behavior) what supports the importance of acridine ion formation in the mechanism of antimicrobial action.     

Allozyme Polymorphisms and Biochemical-Genetic Taxon Markers in Lampreys (Lampetra, Eudontomyzon, Petromyzon)

Variation at 23 putative enzyme-coding loci was scored in 424 lampreys, including 321 European brook lampreys (Lampetra planeri), 83 European river lampreys (L. fluviatilis), 11 Ukrainian brook lampreys (Eudontomyzon mariae), and nine sea lampreys (Petromyzon marinus). Twelve polymorphisms are described for Lampetra species (LDH*, SOD-2*, PNP*, AAT-1*, AK-1*, ES-2*, LGL*, MPI*, GPI-1*, GPI-2*, PGM*, IDHP-2*), and two each for E. mariae (GPI-1*, ME-2*) and P. marinus (MDH-1*, ME-2*). Diagnostic allozymes are presented for the discrimination of lamprey taxa, some of which are difficult to recognize from the morphology of ammocoetes larvae, the life stage usually encountered when collecting cyclostomes. The allelic markers described permit the clear allocation to a genus, except for the species L. fluviatilis and L. planeri, which are not differentiated by qualitative allozyme analysis.     

Survival of diazotrophic cyanobacteria in soil

The survival under drough conditions for one year of 12 heterocystous cyanobacterial strains inoculated in three different soil types (silt clay, calcareous clay and silt loam) gave the highest survival (50%) forScytonema 208L.Fischerella 288L andNostoc OP25 also showed significant survival. Moreover, the soils inoculated withFischerella 288L andScytonema 208L had a higher total N content than non-inoculated soils.     

Submerged cultivation of edible white-rot fungi on tree bark

Summary Three white-rot fungi,Phanerochaete chrysosporium, Polyporus anceps, andPleurotus sapidus, were grown in shake flasks on maple and cedar bark. The barks for growth were extracted with 1% NaOH and microbial growth was estimated by biuret protein. The maximum yields were 136 and 116 mg protein/gm of bark forPhanerochaete chrysosporium andPolyporus anceps and occurred at 4 days. These two fungi were active cellulase producers and were shown to exhibit an extensive linear phase during batch growth.Pleurotus sapidus produced laccase but negligible growth. A non-linear relationship between bark concentration and protein yield was found.     

Germplasm conservation of the tropical forest trees,Cedrela odorata L.,Guazuma crinita Mart., andJacaranda mimosaefolia D. Don., by shoot tip encapsulation in calcium-alginate and storage at 12–25°C

Germplasm conservation of the tropical forest trees,Cedrela odorata L.,Guazuma crinita Mart., andJacaranda mimosaefolia D. Don., at above-freezing temperatures following alginate-bead encapsulation was attempted. Shoot tips excised from in vitro plantlets were encapsulated in calcium-alginate beads and stored on different substrates at 12, 20, and 25 °C. Percent viability when encapsulated shoot tips were stored on substrate containing only water solidified with 1% (wt/vol) agar was 80% after 12 months at 12°C forC. odorata, 90% after 12 months at 25°C forG. crinita, and 70% after 6 months at 20°C forJ. mimosaefolia.Abbreviations BAP 6-Benzylaminopurine - KIN 6-Furfurylaminopurine     

Biological aspects of the geranium mites,Coptophylla caroliniani andAceria mississippiensis (Prostigmata: Eriophyidae)

Aceria mississippiensis andCoptophylla caroliniani (Prostigmata: Eriophyidiae) were found on wild geranium,Geranium carolinianum L., in northern Mississippi. About onehalf of the total developmental time was spent in the egg stage for each species. The developmental threshold forA. mississippiensis was 5.5±1.04°C and 7.3±0.93°C forC. caroliniani. The optimum temperature for each developmental stage was between 25 and 29°C.C. caroliniani failed to develop at 36°C, whereasA. mississippiensis failed at 40°C. Day-degree requirements to complete development were 100.7±3.6 D^o and 154.6±4.1 D^o forC. caroliniani andA. mississippiensis, respectively.Mean female longevity at 20°C was 17.4 (range 12–21) days forC. caroliniani and 16.5 (range 15–19) days forA. mississippiensis. The shortest pre-oviposition period was 2.2 days forC. caroliniani at 20°C and 1.7 days forA. mississippiensis at 25°C, and the length of pre-oviposition period increased with temperature above 25°C for both species.Maximum egg production ofC. caroliniani andA. mississippiensis occurred at 20°C. There were no differences (P0.05) in number of eggs per day at temperatures of 20, 25 and 32°C for each species, but there was a tendency to lay more eggs per day with increasing temperature. The percentages of egg hatch were not significantly different at these temperatures. The sex ratio of laboratory-rearedA. mississippiensis was 1:1.8, whereas field-collectedC. caroliniani showed a ratio of 1:1.     

Amylase synthesis inAspergillus flavus andAspergillus niger grown on cassava peel

Summary Aspergillus flavus andAspergillus niger produce extracellular amylase into the culture medium when grown on basal medium containing 2% (w/v) soluble starch or cassava peel as the sole carbon source. On soluble tarch the highest amylase activities were 1.6 and 5.2 mg of starch hydrolyzed/min per mg protein forA. flavus andA. niger, respectively. When grown on cassava peel, the highest amylase activity in the culture filtrate ofA. flavus was 170-times higher than that on soluble starch, while that ofA. niger was 16-times higher. The mycelial dry weight for both organisms was not significantly affected by the carbon sources. Maximum enzyme activity was obtained at the growth temperature of 29.0±1°C and pH 7 for both organisms. It is concluded that cassava peel might be a better substrate for the production of amylase byA. flavus andA. niger than commercial soluble starch.