bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenol and cresol metabolism in Bacillus pumilus isolated from contaminated groundwater
Authors: Günther K. , Schlosser D. , Fritsche W.
Published: February 2007

From an aquifier contaminated with phenolic compounds seven bacterial strains able to grow on phenol and several mono‐ and disubstituted alkylphenols as sole source of carbon and energy were isolated. Five isolates belong to the genus Pseudomonas, two to the genus Bacillus. The isolate most active in utilization of the applied xenobiotics was identified as Bacillus pumilus and used for the investigation of the degradation pathways in liquid cultures. Cells of this strain precultured on phenol were able to utilize para‐cresol as sole carbon source via the oxidation of the methylsubstituent and intradiol ring cleavage of the resulting protocatechuic acid, whereas an intradiol ring fission of the intermediate 4‐methylcatechol led to 4‐methylmuconolactone as dead end‐product. Cells precultured on meta‐ and ortho‐cresol were able to utilize the respective compounds as sole carbon sources via 3‐methylcatechol, which induced the following extradiol ring fission pathway. Cells precultured on phenol were able to cooxidize meta‐ as well as ortho‐cresol to 3‐methylcatechol, which was cleaved via an intradiol ring fission, finally leading to the dead end‐product 2‐methylmuconolactone.
Effects of NaCl stress on the growth dynamics and protein content of Rhizobium DDSS 69
Authors: Natarajan K. , Kishore L. , Babu C. R.
Published: February 2007

Sodium chloride stress results in an increased lag phase of Rhizobium culture at inhibitory concentrations without affecting either the mean generation time (MGT) or the duration of log period. Irrespective of the phase of addition of NaCl the cells exhibited a ‘critical’ phase. Osmoprotectants do decrease the period of ‘critical’ phase but only if added prior to or along with the addition of NaCl. There is a progressive decrease in the protein content of cells grown under NaCl stress and betaine has no effect on the protein content.
β‐amalyse production by immobilized cells of Bacillus megaterium B6
Authors: Ray Rina Rani , Jana Subhas Chandra , Nanda Geeta
Published: February 2007

Whole cells of Bacillus megaterium B6 were immobilized by ionotropic, thermal gelation and polymerization of which ionotropic gelation was found to be most suitable process for α‐amylase production. Strontium was proved to be the best divalent cation for alginate entrapment of cell in terms of enzyme production and reusability of the cells.
Pulse feeding with nitrate and phosphate in relation to tissue composition and nutrient uptake by some macroalgae from the Red Sea at Ghardaqa (Egypt)
Authors: Aisha Kh. Abou , Shabana Effat F. , El‐Abyad M. S. , Kobbia I. A. , Schanz F.
Published: February 2007

This investigation aimed at determining the effects of experimental enrichment with either N or P or both elements on the tissue nutrient levels, and on the internal N: P molar ratios of three macroalgal species collected in the vicinity of Ghardaqa, Red Sea, Egypt

The results obtained showed that the rates of nutrient (nitrate and phosphate) uptake were highly species dependent. Uptake rates of both nutrients were significantly higher forCodiumthan for eitherDictyotaorGalaxaura.For the three algae, uptake, except nitrate byGalaxaura, was rapid during the first 6 h of immersion and declined during the rest of the experiment. The observed increases in N levels after 6 h of enrichment decreased sharply after 24 h of enrichment. The fluctuations in tissue‐N were accompanied by fluctuations in protein levels. Total carbohydrate content of the three macroalgae was decreased in seawater treatments enriched with either N or N+P for 24 h compared with non‐enriched plants or plants enriched with P only. For the three macroalgae, enrichment with P resulted in consistent increases in tissue‐P levels over the experimental period. The changes in the N:P ratios of the three plants were significantly correlated with the increases in tissue ‐P as compared to tissue ‐N.G. rugosaappeared to be the most strongly nutrient ‐ limited of the three algal species studied andD. dichotomawas the least.
Kinetic studies on the yeastPhaffia rhodozyma
Authors: Acheampong Edward A. , Martin Antonio M.
Published: February 2007

The yeastPhaffia rhodozyma, a promising microbial producer of the carotenoid astaxanthin, was cultivated in batch and continuous processes in an agitated and aerated fermenter using an acid peat extract ‐ based culture medium. For the accelerated growth phase, the mean specific growth rate and doubling time were found to be 0.038 h−1, and 18.24 hours, respectively. The production of astaxanthin was found to be basically growth associated, the maximum concentrations of the pigment produced in batch culture and continuous cultivation being similar.
Ultrastructure of circulating immune complexes isolated from the blood plasma of patients suffering from infectious diseases
Authors: Didenko L. V. , Andreevskaya S. G. , Konstantinova N. D. , Buchwalow I. B.
Published: February 2007

An original procedure which permits to isolate circulating immune complexes (CIC) from the blood plasma in a form of a dense pellet was developed. This procedure was applied for the ultrastructural analysis of CIC isolated from blood of healthy blood donors and patients suffering from Yersinia enterocolitica (YE) and Yersinia pseudotuberculosis (YP) infections. The here reported method of CIC isolation from blood plasma permitted to visualize CIC electronmicroscopically as amorphous masses of low, middle, and high electron density with inclusions of cell debris. In contrast to CIC of healthy blood donors, CIC of infected patients contained various bacteria and fungiformic structures. For the first time, this method made possible an ultrastructural demonstration of bacterial destruction outside of phagocytes in vivo. This method also permits to visualize and identify bacteria in cases of lingering forms of infection when hemoculture tests fail. Therefore, electronmicroscopic examination of CIC preparations from the blood plasma might be a very informative indicator of bacteriemia in the course of an infection process and serve as an indicator of therapeutic effects. In lingering forms of an infection process, ultrastructural analysis of CIC preparations can be of prognostic value and serve as an indicator of therapeutic effects. This method might be also advantageous as an additional test for the exposure of latent bacterial persistence in diagnostically complicated cases.
Catabolite repression of inductive polygalacturonase synthesis in Penicillium expansum by sucrose
Authors: Piccoli‐Valle Roberta Hilsdorf , Baracat‐Pereira Maria Cristina , Silva Daison Olzany
Published: February 2007

Polygalacturonase (PG) synthesis by the fungus Penicillium expansum in the presence of a combination of pectin and sucrose corresponding to 0.3% of the substrate was repressed more intensely by increasing sucrose concentrations and decreasing pectin concentrations. PG synthesis was partially repressed when sucrose was added 6 or 12 h after the beginning of culture and fully repressed when sucrose was added at the beginning of culture. Tests with actidione indicated that repression by sucrose occurs at the transcription level. We suggest that an accumulation of messenger RNA occurred when the fungus was cultured for 36 h in 0.3% pectin and actidione since, after being washed and reincubated in actidione‐free medium in the presence of the repressor, the fungus synthesized PG up to 54 h of culture, when a reduction in accumulated messenger RNA and PG synthesis occurred. Repression by sucrose was reversible since the fungus started synthesizing PG again in the absence of the repressor and in the presence of the inducer.
Auswirkung der Änderung der Lipidzusammensetzung in Plasmamembranen von Saccharomyces cerevisiae durch Mutation auf das Phasen‐ und Mischungsverhalten der Lipidanteile
Authors: Dörfler H.‐D. , Fabian B.
Published: February 2007

Mutation of Saccharomyces cerevisiae leads to an alteration of the size and surface structure of the mutant cell. These phenomena are correlated with change in the lipid composition and hence membrane fluidity of the plasma membranes. Such alterations are in the fatty acyl constituents of phospholipids and glycolipids and include changes in the saturation or length of fatty acyl chains. Simultaneously, the „melting point”︁ of phospholipid fractions, i.e. the temperature of the ordered‐disordered phase transition and mixing behavior, changed. Consequently calorimetry on isolated phospholipid fractions extracted from plasma membranes is a useful analytical method to demonstrate directly such phase transitions and change in the mixing behavior of the cellular lipid fractions in connection with mutation. A correlation between the alteration of the lipid composition in the plasma membrane of strains of S. cerevisiae S 288 and its mutant VY 1160 is discussed.
The properties of the multicopy suppressor of the ogdl mutation in yeast
Authors: Gbelská Yvetta , Mockovčiaková Daniela , Timko Jozef , Šubík Július
Published: February 2007

The 8.1 kb chromosomal fragment partially suppressing the ogdl mutation in Saccharomyces cerevisiae has been cloned. The molecular analysis revealed that its suppressor gene codes for a natural glutamine tRNACAG and maps on chromosome XIII in the upstream region of the URA10 gene. The multicopy plasmids containing this tRNA gene also suppressed the standard trpl‐l amber mutation and conferred the sensitivity of yeast cells to paromomycin and increased temperature.
Effect of different carbon sources on growth and glutamic acid fermentation by Brevibacterium sp.
Authors: Nampoothiri K. Madhavan , Pandey Ashok
Published: February 2007

Experiments were carried out to find the efficiency of Brevibacterium sp. to utilize different carbon sources (glucose, fructose, sucrose, maltose, lactose, xylose and starch) for its growth and for the production of glutamic acid. Except starch, all the carbon sources supported the growth of the culture, which showed a preferential choice of growth and activity when grown on glucose as sole carbon source. Mixed substrate fermentation did not improve the yield of amino acid. Maximum glutamic acid yields (6.86 mg/ml) were obtained when 2% glucose medium was fermented under optimized conditions for 48 h.
Studies on rifamycin production by Amycolatopsis mediterranei cells immobilized on glass wool
Authors: Abu‐Shady Mohamed R. , El‐Diwany Ahmed I. , Farid Mohamed A. , El‐Enshasy Hesham A.
Published: February 2007

Cells of Amycolatopsis mediterranei CBS 42575 were immobilized on glass wool for the production of rifamycins B and SV. Glass wool (CORNING type) of 8 microns in diameter has a better entrapment capacity for microbial cells of microorganism than the other types of glass wool used. The most suitable amount of glass wool was 0.8 g/50 ml. The best initial cell concentration used as inoculum was 40 mg cells/50 ml. Repeated batch production of rifamycins by immobilized cells on glass wool was carried out for 6 repeated batches. The results showed that reduction of batch time from 96 h to 48 h does not decrease rifamycin production by immobilized cells.
Salt‐ and pH‐dependent hemagglutination with Kasba virus, a member of the Palyam serogroup of the genus Orbivirus
Authors: Jusa E. R. , Inaba Y.
Published: February 2007

Kasba virus grown in BHK21‐WI2 cells was tested for hemagglutination (HA) with erythrocytes of a variety of species at 4°C, 25°C and 37°C. HA was observed at all temperatures with cattle, sheep and goat but not with swine, chicken, and goose erythrocytes. The HA was dependent on not only the NaCl concentration but also the pH of the diluent. The HA titer significantly improved by increasing the NaCl molarity to 0.6 M and standardizing pH to 7.5. The HA titer was 16‐ or 32‐fold higher in 0.4 M or 0.6 M solution than in 0.2 M solution of not only NaCl but also several other salts. The HA reaction was inhibited by specific antibody.
A rapid method for differentiation of Xanthomonas campestris pv. mangiferaeindicae from other Xanthomonads and mango phylloplane inhabitants
Authors: Sanders Gina M. , Korsten L.
Published: February 2007

A rapid method for differentiation of Xanthomonas campestris pv. mangiferaeindicae from other Xanthomonads and phylloplane inhabitants is described. Several selective media were evaluated for selective enrichment of X. campestris pv. mangiferaeindicae from mango plants. Boost broth supplemented with cycloheximide, methyl violet and methyl green enhanced growth of epiphytic X. campestris pv. mangiferaeindicae but not other phylloplane organisms. The identity of X. campestris pv. mangiferaeindicae selectively enriched from mango plant material was confirmed with monoclonal antibodies in an Enzyme‐Linked Immunosorbent Assay. Preliminary field evaluations showed that selective enrichment and confirmation by ELISA could successfully detect latent infections of X. campestris pv. mangiferaeindicae in mango plants.
Effect of previous growth conditions on starvation survival and endogenous metabolism rate of Arthrobacter fluorescens
Authors: Cacciari Isabella , Lippi Daniela , Pietrosanti Tito , Pietrosanti Walter
Published: February 2007

The starvation survival and the endogenous metabolism rate were studied in cultures of Arthrobacter fluorescens grown at various dilution rates under ammonium‐limited conditions. In addition, the ammonium‐limited cultures grown at dilution rates of 0.03 and 0.20 h−1 were made oxygen‐limited and these cultures were also studied. Suspensions of washed cells from all the steady state cultures were incubated under total nutrient deprivation at 30°C for 20 days. The effects of starvation on cell counts, protein and carbohydrate contents and endogenous respiration rates were determined. Viable cell count of suspensions grown under ammonium‐limited conditions declined faster for the cells grown at faster dilution rates. On the contrary starved slow growing oxygen‐limited cells showed a more rapid decrease in viability than the fast growing ones. Cell dry weights, carbohydrates and proteins declined exponentially during starvation and their rates of change were generally greater with cells grown at higher dilution rates, irrespective of nutrient limitation. Starved oxygen‐limited cultures exhibited a higher death rate and a greater reserve material mobilization than ammonium‐limited cultures grown at the same dilution rate.
Characterization of a methanol‐utilizing sulfate‐reducing bacterium isolated from a wastewater pond
Authors: Hard Barbara C. , Babel Wolfgang
Published: February 2007

A methylotrophic, mesophilic, gram‐negative sulfate‐reducing bacterium, named strain UFZ B378, was isolated from the sediment of a wastewater pond of a derelict sugar factory. The rod shaped to slightly curved cells are motile and 1.5 to 3.5 um long and 0.5 um wide. Formation of spores was not observed. The G+C content of the DNA was 58.7 mol%. Sulfate is used as electron acceptor, methanol can be used as sole source of carbon. Other electron donors included pyruvate, lactate, acetate, ethanol, butanol, propanol, choline, betaine, succinate, fumarate and benzoate without the addition of H2. Growth occurred from pH 4 to 9.0, the optimum pH was found to be around 7.0. The temperature range for growth was between 3°C and 40°C, with an optimum at 30°C. Vitamins or other supplines were not required. The strain was found to be tolerant to ferric and ferrous sulfate (5 mM and 100 mM respectively) on their own and in combination in the culture medium. The pH in batch cultures with methanol increased from 6.3 to 8.0 over a period of 48 days due to the reduction of sulfate and formation of hydrogen sulfide. Production of methane was not found.
Production of α‐galactosidase by Lactobacillus plantarum isolated from diverse sources
Authors: Sanni I. A. , Ahrne S. , Onilude A. A.
Published: February 2007

α‐Galactosidase activity was observed in six strains of Lactobacillus plantarum isolated from fermented cereal products, human intestinal flora and fermented tea. The cultural conditions under which the enzyme activity was detected suggest that the enzyme is inducible. Development of mutants in four out of the six strains was observed and the mutants recorded high enzyme activity than the parent strains. Effect of different carbohydrates on enzyme activity showed glucose and raffinose being repressive in the parent strains. Although all the carbohydrate sources supported growth, highest amount of enzyme activity was recorded on lactose and glucose. The enzymatic potential of L plantarum in reducing flatulence properties of the raw material base of some West African fermented foods is suggested.
The effect of ultrasound on Escherichia coli viability
Authors: Allison D. G. , D'Emanuele A. , Eginton P. , Williams A. R.
Published: February 2007

The effect of continuous‐wave ultrasound on the viability of Escherichia coli HB101 was assessed using a 20 kHz ultrasonic processor. A standardised cell suspension of fixed concentration was used to investigate the influence of different physical and environmental conditions on ultrasound susceptibility. Cell viability decreased exponentially with time at different intensities of ultrasound. Increasing intensity caused a decrease in decimal reduction times. Loss of cell viability occurred primarily from the mechanical effects of ultrasound rather than free radical damage. E. coli susceptibility was also shown to vary with growth conditions, whereby cells cultivated either on agar or harvested from the stationary phase of liquid culture were significantly more susceptible to ultrasound than an equivalent population obtained from the exponential phase of liquid growth. The implication of these results is discussed in relation to the use of ultrasound as a novel means of bacterial transformation.
Decolorisation of the polymeric dye Poly R by Streptomyces viridosporus T7A
Authors: Ball A. S. , Colton J.
Published: February 2007

The ability of a range of actinomycetes to decolorise the polymeric dye Poly R was investigated. Three well characterised lignocellulose‐degrading actinomycetes, Streptomyces viridosporus, Streptomyces badius and Thermomonospora mesophila were found to be the most efficient at decolorising Poly R, with a maximum decolorisation rate of 0.10 unit per day. Extracellular fractions taken from S. viridosporus grown on a variety lignocellulose‐related substrates were also capable of decolorising Poly R, indicating that dye decolorisation was not merely due to biomass uptake. The activity of extracellular fractions from straw‐grown cultures of S. viridosporus was three to six times greater than those from other substrates examined. Purification of this dye‐decolorising activity from S. viridosporus using anion exchange chromatography revealed the presence of a single active fraction. This was confirmed using gel permeation chromatography which estimated the molecular mass of the decolorising protein to be approximately 30000 Da.
Biosynthetic capacities of actinomycetes. 5. Dioxolides, novel secondary metabolites from Streptomyces tendae
Authors: Blum Sabine , Groth Ingrid , Rohr Jürgen , Fiedler Hans‐Peter
Published: February 2007

Dioxolides, a novel class of secondary metabolites were detected by a HPLC‐diode array screening technique in the culture filtrate of Streptomyces tendae Tü 4042. The compounds show no biological activity against Gram‐positive and Gram‐negative bacteria, yeasts and fungi. Besides dioxolides, which consist of an unusual substituted dioxolane ring, anhydroshikimate and para‐hydrobenzamide were detected by this technique. Both compounds were not yet described as natural products.
The isolation of Akabane virus (Iriki strain) from calves in Taiwan
Authors: Liao Y. K. , Lu Y. S. , Goto Y. , Inaba Y.
Published: February 2007

Nonsuppurative encephalitis in calves aged 4–12 months, cow abortion and fetal deformities were endemic in dairy farms in Taiwan in recent years. A virological investigation emphasizing on Arthpodborn virus (Arbovirus) was conducted. Total of 11 strains of Akabane virus were isolated from endemic districts between June and July of 1992. Among them, seven viruses were isolated from blood samples of 15 calves showing nervous signs. Another 4 Akabane viruses were isolated from clinically healthy calves from three of six dairy farms investigated. All the six investigated farms had a recent history of abortion and fetal deformities. The isolates caused prominent cytopathic effects in HmLu‐1 cells and could reach a high virus titers (5 × 106 TCID50/ml). As demonstrated by a cross neutralization test, the isolates had identical antigenicity to Iriki strain of Akabane virus, but were antigenically more distant to JaGar‐39 and OBE‐1 strain of Akabane virus. This is the first report on the isolation of Akabene virus in Taiwan, and also the second report on the isolation of Iriki virus in the world.
Microbiological status of selected chicken carcases from a non‐automated poultry processing plant
Authors: Olivier Maretha , Veary C. M. , Cloete T. E. , von Holy A.
Published: February 2007

The microbiological status of chicken carcases sampled at three different processing points in a South African Grade B poultry abattoir slaughtering ca. 750 birds per hour, was determined. Six skin samples and two meat samples were aseptically collected from different sites on each carcase. Total bacterial counts were performed at 25 °C, 37 °C and 43 °C and all colonies from plates showing between 30 and 300 cfu were characterised. Bacterial counts of the skin samples at 37 °C were consistently the highest, followed by those at 25 °C and then 43°, but for the two meat samples the highest bacterial counts were found at 37 °C and the lowest at 25 °C. Neck skin counts were marginally higher than bacterial counts of the other skin samples. The Gram negative genera Escherichia and Acinetobacter were isolated most frequently at all three incubation temperatures and from all sampling sites, while the dominant Gram positive genera were Staphylococcus and Enterococcus. Escherichia isolates predominated on the skin sampling site cranio‐dorsal to the pygostyle, whilst Staphylococcus isolates predominated on the skin sampling site caudal to the breastbone. Microbiological contamination is a major problem in the abattoir studied and further studies should therefore aim to determine points of maximum contamination in the processing line.
Diversity of microfungi in the sandy soil of Ipanema Beach, Rio de Janeiro, Brazil
Authors: De Moura Sarquis Maria Inez , De Oliveira Pedrina Cunha
Published: February 2007

The mycobiota of the sandy soil of Ipanema Beach, Rio de Janeiro, Brazil, was investigated in 144 sand samples collected at four different sites along the sea coast, divided into three subsites. for a period of one year. A total of 4285 yeast colonies and of 6956 of colonies filamentous fungi were isolated using conventional media and techniques. Representatives of the filamentous fungi corresponding to a total of 1334 colonies were identified and assigned to 34 genera and 170 species. The genera of highest incidence and their respective numbers of species were as follows:Aspergillus, 30.4%, 32 spp.;Penicillium, 16.2%, 35 spp.;Fusarium, 12,6%, 33 spp.:Trichoderma, 6.4%, 7 spp.;Paecilomyces, 3.7%, 10 spp.:Cladosporium, 3.1 %, 8 spp. andAcremonium, 1.0%, 8 spp. Several other genera and species were detected at quite low occurrences. Non‐sporulating fungi (18.3%) and Coelomycetes (Sphaeropsidales) (1.9%) were also detected. Most of the genera detected belonged to theDeuteroycotina, with fewer proportions belonging to theAscomycotinaandZygomycotina.Moniliaceaewas represented by the largest number of species andDematiaceaewas represented by the largest number of genera. In terms of seasonal distribution, the largest number of filamentous fungi was isolated during the winter and the smallest number the Summer.
Molecular investigations on the dilemma of nitrogen‐fixing characteristics of Azotomonas
Authors: Lee Saehong , Pulakat Lakshmidevi , Hausman Bryan S. , Efuet Ekem T. , Lei Shi , Gavini Narasaiah
Published: February 2007

The ability of Azotomonas to reduce atmospheric nitrogen has been an issue of controversy since this genus was included in the family Azotobacteraceae. Here we report the investigations on the nitrogen fixation characteristics of Azotomonas fluorescens strain ATCC13544 and show that it can grow in both liquid medium and on solid agar plates made with modified BURK nitrogen‐free medium supplemented with ammonium acetate as a nitrogen source. In contrast, when ammonium acetate was omitted from this medium, the cells did not show any noticeable growth. Southern blotting analysis of the chromosome of Azotomonas strain ATCC13544 did not show any hybridization with a probe made of DNA sequences corresponding to the nifH gene of Azotobacter vinelandii. Based on these results, we conclude that the Azotomonas fluorescens ATCC13544 does not contain the conventional genetic information on its chromosome that is needed to utilize atmospheric nitrogen as the sole source nitrogen to support its growth.
The presence of glutamine synthetase in the thylakoids of nitrogen‐fixing cyanobacterium Nostoc muscorum
Authors: Sallal Abdul Karim J.
Published: February 2007

The intracellular distribution of glutamine synthetase (GS) in cell‐free extracts of Nostoc muscorum has been investigated. 64–73% of the enzyme activity was associated with the thylakoid membranes. No enzyme activity was found in cytoplasmic membranes. 92% inhibition of the enzyme activity was obtained with an antiserum raised to the thylakoids using Triton‐treated membranes, in comparison to 7.95% inhibition with the intact membranes. This suggests that the majority of the enzyme is embedded inside these membranes. This was also supported by the effect of pronase on the exposed glutamine synthetase using intact membranes.
Fungal spore concentrations in the atmosph at the Anatolia quarter of Istanbul, Turkey
Authors: Çolakoglu Günay
Published: February 2007

In this research, spore concentrations ofCladosporium, Alternaria, Epicoccum, Botrytis, Leptosphaeria, Polythrincium, ascospores, Aspergillits, Penicillium, basidiospores, uredospores,Ustilago, Torula, Erysiphe, Ganoderma, Hyaline indeterminateand others in the atmosphere have been determined, and comparisons have been made between locations with both low and high spore concentrations. The importance of these air‐borne fungal spores which cause allergy and asthma are emphasized in the paper from the viewpoint of human health.
Some factors affecting endo‐β‐1,4‐glucanase production by two Bacillus strains isolated from Zimbabwean hot springs
Authors: Mawadza Crispen , Zvauya Remigio
Published: February 2007

Two Bacillus strains capable of producing endo‐β‐1,4‐glucanase enzyme were isolated from Zimbabwean hot springs. Strain HR68 produced the enzyme when cultured using both carboxymethylcellulose (CMC) and simple sugars as carbon source while strain CH43 produced the enzyme on CMC only. The optimum conditions for enzyme production were an initial pH of 6 and a temperature of 50 °C for strain HR68 while for strain CH43 the optimum conditions for enzyme production were an initial pH of 5 and a temperature of 50 °C. A fall in enzyme production was observed after about 4 to 8 h of growth for both isolates. The fall in production coincided with a rise in proteolytic activity in cultures of both isolates. Strain HR68 produced endo‐β‐1,4‐glucanase when grown in continuous culture using glucose as the carbon source.
Proteolytic activities in cultures of selected white‐rot fungi
Authors: Staszczak Magdalena , Nowak Grzegorz , Grzywnowicz Krzysztof , Leonowicz Andrzej
Published: February 2007

The presence of multiple intracellular and extracellular proteolytic activities in trophophasic (nutrientrich) and idiophasic (carbon‐or nitrogen‐starved) cultures of the white‐rot fungi Trametes versicolor and Phlebia radiata was demonstrated by electrophoresis on polyacrylamide gels containing denatured haemoglobin as a substrate. In the trophophasic cultures of T. versicolor, seven electrophoretically distinguishable proteases were defined using mycelial extracts and six (three clear and three less intensive) of secreted proteases. For P. radiata eight bands of intracellular and five bands (one distinct and four less active) of extracellular proteolytic activities were detected. Gel electrophoresis revealed changes in patterns of secreted and mycelial proteinases upon carbon or nitrogen deprivation. The changes were seen both as an increase in activity of certain bands and as the appearance of new proteolytic bands. Specific activities of extracellular proteinases, assayed under idiophasic (—C or —N) conditions, increased 2—3 fold as compared to those upon nutrient sufficiency. These changes accompanied a shift to secondary metabolism and onset of ligninolytic activity.
Enantiospecific reduction of prochiral ketones of aromatic type to optically active alcohols inNigrospora oryzaeculture
Authors: Jarosz Bogdan , Siewiński Antoni
Published: February 2007

The culture ofNigrospora oryzaereduces twelve prochiral ketones of homo‐ and heteroaromatic type (acetophenone, 3‐ and 4‐methylacetophenone, 4‐nitroacetophenone, propiophenone, 2‐acetylnaphtha‐lene, 2‐acetyltiophene, 2‐ and 4‐acetylpyridine,α,α,α‐trifluoroacetophenone, α‐tetralone, 4‐benzoyl‐pyridine) enantiospecifically to corresponding optically active alcohols. The enantiomer of S configuration is in nine cases predominant, R configuration was found in three alcohols. The degree of chemical reduction determined in GC ranged from 20% to almost 100%, while optical purity was from 5% to 100% ee. It is worth noting that the same culture did not reduce 4‐aminoacetophenone, 2‐acetylpyrrole and 2‐acetylindole.
Alnus incana response on treatment with fluorescent Pseudomonas sp. strain 267
Authors: Małek Wanda
Published: February 2007

Fluorescent Pseudomonas sp. strain 267 was evaluated for its ability to stimulate the growth of A. incana in vitro under gnotobiotic and nongnotobiotic conditions, as well as in the presence and absence of FeCl3 as iron source. Bacterization of grey alder roots with Pseudomonas sp. strain 267 promoted plant growth under each of the studied conditions. The dry weight of leaves and roots increased significantly when compared with the uninoculated plants. Chlorophyll concentration in the leaves of grey alder, treated with fluorescent pseudomonad, was positively correlated with plant growth stimulation. Its concentration showed 50% increase over the control uninoculated plants. Moreover, it is supposed, that A. incana growth promotion by Pseudomonas sp. strain 267 may result from secretion of vitamins by this bacterium, which can be utilized by plant.
Soluble cell‐bound and extracellular cyclodextrin glycosyltransferases of Bacillus macerans show identical enzymological characteristics and antigenicity
Authors: Nógrády Noémi , Pócsi István , Katona Éva , Jeney Viktória , Boross Péter , Tözsér József , Fachet József , Szentirmai Attila
Published: February 2007

Soluble cell‐bound and extracellular cyclodextrin glycosyltransferases of Bacillus macerans were purified to homogeneity using the subsequent steps of adsorption on starch, ion‐exchange chromatography and gel filtration. The elution profiles and the relative molecular masses of the enzymes as well as their N‐terminal sequences were found to be identical. Moreover, mouse monoclonal antibodies raised against the soluble cell‐bound enzyme recognised equally well both the cell‐bound and the extracellular enzyme preparations. Regarding that no signal peptide could be detected in either the cell‐bound or the extracellular cyclodextrin glycosyltransferase the enzyme was probably entrapped between the cell membrane and the cell wall in the early stationary phase and was released during cell lysis without any modification.
Phylogenetic relationships of entomopathogenic nematophilic bacteria: Xenorhabdus spp. and Photorhabdus sp.
Authors: Suzuki Tomonori , Yabusaki Hiroaki , Nishimura Yukimasa
Published: February 2007

Phylogenetic relationships of Xenorhabdus spp. and Photorhabdus sp. were investigated on the basis of 16S rRNA gene sequences. Xenorhabdus spp. and Photorhabdus sp. were grouped together with Proteus vulgaris and Arsenophonus nasoniae. This group was distant from other members of the family Enterobacteriaceae. Xenorhabdus japonicus, previously proposed as a new species, was nearly located to Xenorhabdus nematophilus. Signature nucleotides of X. japonicus were identified that distinguish it other members of the family Enterobacteriaceae.
Evaluation of defined media suitable for isolation of auxotrophic mutants of mycobacteria
Authors: Wards Barry J.
Published: February 2007

In order to investigate the production of auxotrophs of slow growing mycobacterial pathogens, an evaluation of defined liquid and solid media suitable for Mycobacterium tuberculosis, Mycobacterium bovis and Mycobacterium paratuberculosis was undertaken. Five defined liquid media were evaluated. A number of solid support matrices was added to the liquid media to produce solid media for evaluation. Tween 80 was added to all media to produce diffuse homogeneous growth. Although satisfactory growth in defined liquid media was achieved with all strains tested, poor growth was generally observed in the equivalent defined solid medium for strains belonging to the tuberculosis complex. Only M. paratuberculosis produced satisfactory growth on defined solid media, especially on Middlebrook 7H9. The inhibitory effect of Tween 80 and the presence of inhibitory factor(s) in agar were confirmed. Partial removal or inactivation of these factors by the addition of absorbents to the media was achieved.
A pullulan‐degrading enzyme activity of Aureobasidium pullulans
Authors: West Thomas P. , Strohfus Beth
Published: February 2007

A pullulan‐degrading enzyme activity was detected in the culture medium after growth of the fungus Aureobasidium pullulans on corn syrup as a carbon source. The product of pullulan catabolism by this activity was determined to be glucose. The highest specific activity of this enzyme was found after 7 days of fungal growth. Although α‐amylase activity was not detectable, the presence of a glucoamylase activity was indicated. It appeared that the enzyme responsible for pullulan degradation was likely glucoamylase B.
Steroid transformation by mutants of Mycobacterium sp. with altered response to antibiotics
Authors: Barthakur Sharmistha , Roy Monoj K. , Bera Saphal K. , Ghosh Anil Ch.
Published: February 2007

Mycobacterium sp. NRRLB3683 which is capable to convert β‐sitosterol to 1,4‐androstadiene‐3, 17‐dione (ADD) was treated with methyl methane sulfonate and two strains with altered sensitivity to various antibiotics were obtained. One of the strain was steroid 1(2)‐dehydrogenase negative and the other positive. Efficiency of utilization of sterols followed the order β‐sitosterol > cholesterol > soluble cholesterol. The steroid 1(2)‐dehydrogenase negative strain was capable of producing 17KS (AD) from β‐sitosterol and converting AD to testosterone and ADD to AD suggesting the negative role of 1(2)‐dehydrogenase in sterol side chain cleavage and decrease in hydrogenase activity by mutation. But this enzyme can perform the reverse reaction under aerobic condition.
Mould counts in the atmosphere at the Europe Quarter of Istanbul, Turkey
Authors: Çolakoglu Günay
Published: February 2007

Daily mould counts were made using both exposed slides and Petri dishes, from January 1, 1994 to December 31, 1994 in Europe Quarter of Istanbul, Turkey. The most important moulds were: Cladosporium, Alternaria, Penicillium, Aspergillus and yeast. The peak mould season was early January to early February. Some moulds were present all year.
Differentiation of Rhodococcus species by ribotyping
Authors: Jorks Siegfried
Published: February 2007

The ribosomal RNA gene restriction patterns (ribotyping) was investigated with respect to the characterization of Rhodococcus species and R. rhodochrous strains. Chromosomal DNA was prepared, digested with BamH I, blotted, and hybridized with acetylaminofluorene‐labelled 16 + 23S rRNA from E. coli. The type strains of seven Rhodococcus species studied gave different hybridization patterns in each case. All strains tested were clearly distinguishable by ribotyping. Patterns contained two to eight bands between 1.4 kb and 11.8 kb and demonstrated the high genetic divergence of genus Rhodococcus. Investigation of nine R. rhodochrous strains resulted in patterns with seven or eight bands. One fragment. 4.4 kb in size, was common to all R. rhodochrous strains and appears to be characteristic of R. rhodochrous. Ribotyping was evaluated as a tool for distinguishing between Rhodococcus species.
Regulation of nitrate uptake and nitrite efflux in the cyanobacterium Nostoc MAC
Authors: Singh B. B. , Pandey P. K. , Singh S. , Bisen P. S.
Published: February 2007

Nitrate uptake, nitrite efflux and their regulation have been studied in the cyanobacterium Nostoc MAC. Nitrate uptake as well as nitrite‐assimilation‐dependent nitrite efflux systems consisted of two distinct phases comprising an initial rapid phase followed by a slower one. Whereas, 3‐(3,4‐dichlorophenyl)‐1‐1 dimethyl urea (DCMU), an inhibitor of photosystem II inhibited both nitrate uptake and nitrite efflux significantly, exogenous supply of ATP, however, stimulated both the processes, suggesting that PS II‐mediated energy generation plays vital role in regulating both nitrate uptake as well as nitrite efflux. The inhibition of both the processes by p‐chloromercuribenzoate (pCMB)1, N,N dicyclohexylcarbodiimide (DCCD) and carbonyl cyanide‐m‐chlorophenyl hydrazone (CCCP) indicated the involvement of ‐SH groups and ATP hydrolysis in the regulation of both the processes. Tungstate‐treated cells having nonfunctional nitrate reductase although had a significant level of nitrate uptake, yet nitrite efflux by these cells was found to be negligible. These results suggest that (i) nitrate uptake and nitrite efflux processes in Nostoc MAC are energy‐dependent; (ii) assimilation of nitrate via nitrate reductase is necessarily required for nitrite efflux to occur; (iii) nitrate uptake and nitrite efflux processes are regulated at different levels by different metabolic inhibitors; and (iv) cations of larger ionic radius facilitate the nitrate uptake and nitrite efflux processes.
Different restriction profiles of χ prophage in Serratia marcescens K and HY
Authors: Steiger H. , Kimpel E. , Mohasseb‐Karimlou B.
Published: February 2007

Temperate phage χ originated from the defectively lysogenic Serratia marcescens strain K, from where it was liberated after uv irradiation with low efficiency. The phage is usually indicated on strain HY that can be easily lysogenized by it and rather efficiently uv‐induced. Comparing the Eco RI restriction profiles of the χ prophage in HY revealed a DNA rearrangement, by which the precursor structure in K is converted into the non‐defective form. Apparently the fragment containing the pac sequence is concerned since a phage DNA probe prepared from the assumed initiation fragments of the first particles of the packaging series gave two signals instead of one with genomic K DNA. Since several independent new χ isolates showed the same Eco RI restriction pattern as the original phage of ELLMAUER and KAPLAN (1959), the generation of χ is a reproducible event.
Characterization of two epiphytic bacteria from soybean leaves with antagonistic activities against Pseudomonas syringae pv. glycinea
Authors: Völksch Beate , Nüske Jörg , May Rudolf
Published: February 2007

The strains 48b/90 and 22d/93 are naturally occurring ephiphytes which were isolated from soybean leaves. On the basis of pheno‐ and genotypic characteristics 48b/90 was identified as Erwinia herbicola and 22d/93 as Pseudomonas syringae. These two isolates produced biological active substances against different indicator organisms. The E. herbicola strain showed clear antagonistic properties against Escherichia coli and Pseudomonas syringae pv. glycinea, but not against Geotrichum candidum. 22d/93 was active against P. glycinea and G. candidum, but not against E. coli. Strain 48b/90 produced at least two different inhibitors: an antibiotic substance and an inhibitor of the alginate synthesis. Strain 22d/93 produced at least three different compounds inhibitory to P. glycinea and one to G. candidum. Their activities against the bacterial blight pathogen, P. glycinea, can be observed in planta, too. Under the influences of the antagonists the pathogen multiplied at lower rates and to lower stationary phase population levels. The development of bacterial blight symptoms was suppressed.
Control of the Myc‐Max mediated transactivation in yeast by natural promoter elements
Authors: Hänel Frank , Peukert Karen , Munder Thomas
Published: February 2007

Transcriptional activation studies involving the human oncoprotein and transcription factor Myc and its helix‐loop‐helix partner protein Max in mammalian cells are critical due to the presence of endogenous Myc and Max proteins. Here we show that co‐expression of the human c‐myc and max genes from 2μ circle derived high copy number vectors in yeast cells stimulate the transcriptional activation of a LacZ reporter gene fused to the yeast cytochrome‐c1, oxidase minimal promoter containing the adenovirus major late promoter element (AMLPE). The exchange of the single Myc binding site in the AMLPE by the two E‐box DNA motifs (CACGTG) present in the Myc responsive element of a human Myc target gene (ornithine decarboxylase) in front of a promoter‐reporter gene cassette results in a two‐fold enhanced ß‐galactosidase expression. Low expression of max and high level expression of c‐myc at the same time led to a further enhancement of transcriptional activation from this promoter‐reporter gene cassette.
The metabolism of gluconate in Escherichia coli. The subsidiary system and the nature of the gntS gene
Authors: Istúriz Tomás , Celaya Joseba
Published: February 2007

The transport and phosphorylation of gluconate in E. coli occurs through two systems (GntI and GntII) which duplicate activities. bioH‐asddeletion mutants do not grow on media with gluconate as sole carbon source because they lack the GntI system and do not express GntII. Although E. coli C177 is a Δ(bioH‐asd) mutant, it carries the pyrB linked mutation gnt177 that enables it to metabolize this substrate through inducible expression of the GntII system. Several gntS derivatives which are unable to grow on gluconate were isolated from E. coli C177 by spontaneous curing of the transposon Tn10 previously inserted at the gntS locus (zjf::Tn10, min 95.3). A representative gntS mutant, E. coli TI141A retained the ability to take up gluconate but had lost the thermosensitive gluconokinase activity (gene gntV, min 96.9). Furthermore, it could be demonstrated that gntV is repressed in E. coli TI141A. The results indicate that gntS might specify a trans‐acting positive regulator involved in the control of at least the expression of the thermosensitive gluconokinase (GntII), instead of a gluconate uptake system as it was previously postulated. Likewise, these results can be used to reconsider whether the locus altered by the gnt177 lesion is allelic with that of the GntII permease instead of a regulator, as it was originally postulated.
Localization of alanyl aminopeptidase and leucyl aminopeptidase in cells of Pseudomonas aeruginosa by application of different methods for periplasm release
Authors: Jensch Torsten , Fricke Beate
Published: February 2007

Various methods for the isolation of periplasm were examined and compared with regard to the complete release of known periplasmic marker enzymes and the contamination of the periplasm by cytosol for Pseudomonas aeruginosa PAO1 as a significant Gram‐negative test strain. The aim of the investigations was to clarify the exact localization of alanyl aminopeptidase (AAP) and leucyl aminopeptidase (LAP) of this microorganism and to evaluate these methods.

The osmotic shock of NOSSAL and HEPPEL (1996) was the most effective method with the lowest contamination by the cytosolic marker enzyme malic enzyme, but some proteins, which are located near the inner side of the cytoplasmic membrane, can be released additionally into the periplasm. All other procedures like chloroform or polymyxin treatment, the magnesium chloride washing of intact bacteria and spheroblasting by lysozyme in the presence of EDTA or magnesium chloride resulted only in a partial, sometimes only very low release of periplasm. The periplasmic enzymes are bound either more by hydrophobic or more by ionic interactions to the cell envelope and show a different behaviour with the different releasing agents. These methods are useful for a further differentiation between really periplasmic proteins and those proteins, which were false positive found in periplasm as a result of the osmotic shock. Our results show that AAP from Pseudomonas aeruginosa is a periplasmic enzyme with hydrophobic interactions to the cytoplasmic membrane, corresponding to the early results of LAZDUNSKI and MURGIER for Escherichia coli (LAZDUNSKI et al. 1975a and b, MURGIER et al. 1977), and LAP is cytosolic, but located near the cytoplasmic membrane. The AAP is not a real amphipatic membrane protein, as could be demonstrated by phase separation experiments with Triton X‐114.
The response of three strains of Anacystis nidulans (cyanobacteria) to ultraviolet‐B radiation
Authors: Pandey U. , Chatterjee C.
Published: February 2007

The influnce of UV‐B irradiance was examined on three strains of a cyanobacterium, Anacystis nidulans. These include wild type A. nidulans (An) and strains resistant to cadmium (Cdr) and cyanophage As‐1 (As‐1r). The results indicated that although, the UV‐B radiation considered in the present study was damaging to all the three strains, As‐1r offered some degree of protection from UV‐B as far as changes in chlorophyll, phycocyanin, 14CO2 uptake and photosynthetic O2 evolution were concerned. Cadmium resistant strain appeared to be most sensitive to UV‐B among the three. The observations form the first report of UV‐B effects on a metal resistant and a cyanophage resistant strain of cyanobacterium.
Effect of certain nutrients on the production of dextransucrase from Leuconostoc mesenteroides NRRL B‐512F
Authors: Goyal Arun , Katiyar Sarvagya S.
Published: February 2007

The effects of certain nutrients on dextransucrase (sucrose: 1,6‐α‐D‐glucan 6‐α‐D‐glucosyltransferase EC 2.4.1.5) production from Leuconostoc mesenteroides NRRL B‐512F were studied. An increase in concentration of sucrose to 4% in the enzyme production medium resulted in the increase of activity of dextransucrase. Higher enzyme yields were obtained at low yeast extract and high phosphate concentrations. The presence of peptone and beef extract in the medium in addition to 2% yeast extract resulted in an enhanced production of dextranscucrase. The enzyme activity increased by 30% by both peptone and beef extract. Addition of Tween 80 to the medium enhanced the production of enzyme and the activity was increased by 25%. Magnesium ions stimulated the acitivity marginally. Sodium fluoride enhanced the activity of dextransucrase by 25%.
Surface‐active properties of rhamnolipids from Pseudomonas aeruginosa GS3
Authors: Patel Reena M. , Desai Anjana J.
Published: February 2007

Pseudomonas aeruginosa GS3 produced rhamnolipid biosurfactants during growth on carbohydrates, higher chain length n‐alkanes and l‐alkenes, petroleum crude oil and vegetable oils. With glucose as the substrate, maximum surfactant production (0.44 g/l) was observed during the stationary phase of growth. Partially purified rhamnolipids showed excellent surface‐active properties in terms of reduction in the interfacial tension between them and a variety of hydrocarbons, hydrocarbon mixtures and vegetable oils and formation of stable emulsion.