bluuebunny/crossref_metadata_2025 huggingface dataset:
Conditioning by mitochondria and energy source of thermal death parameters in yeast
Authors: Madeira‐Lopes A. , Cabeça‐silva C.
Published: February 2007

Two strains of Saccharomyces cerevisiae of opposite mating type (a and α), with different resistance to thermal death, and their respective mitochondrial respiratory‐deficient mutants (petites ap and αp) were used to prepare the following diploid strains: aα, aαp and apα. Specific thermal death rates were determined at supramaximum temperatures for growth, under conditions of mitochondrial derepression (glycerol medium). Comparison of the entropies of activation of thermal death showed that diploids aα and apα behaved like the more resistant haploid α, and diploid aαp like haploid a. In glucose medium strains α and aα became even more thermoresistant. The results favour the concept that thermal death determinants are located in the mitochondrial genome, and that mitochondria repressed cells repair thermal injuries more efficiently.
Bioenergetic parameters of Acremonium chrysogenum
Authors: Telesnina G. N. , Bartoshevish Yu. E. , Krakhmaleva I. N. , Petyushenko R. M. , Sazykin Yu. O. , Navashin S. M.
Published: February 2007

Bioenergetic parameters of two isogenic strains of Acremonium chrysogenum markedly differing in their capacity for biosynthesis of cephalosporin C were studied. It was shown that in the high productive strain the system of oxidative phosphorylation played the dominant role in the cellular energy supply (the index of the substrate consumption efficiency amounted to 0.82). In both strains terminal oxidation of the reduction equivalents mainly occurred via the respiration chain with cytochrome oxidase as the terminal component. In the low productive strain an alternative cyanide resistant pathway was observed, in addition to the classic cytochrome chain.

A procedure suitable for the isolation of stable protoplasts from the mycelium of A. chrysogenum was developed. It was proved to be useful in the isolation of functionally active mitochondria possessing theoretical phosphorylation efficiency and high phosphate acceptor respiration control. It was concluded that there are three oxidative phosphorylation sites in the respiration chain of the high productive strain of A. chrysogenum.
Verwertung von Sulfitablauge durch Hefen — Wachstumsparameter von Produktionsstämmen und eines Fusionsstammes
Authors: Weide H. , Bachmann Beate
Published: February 2007

The growth characteristics of a Candida strain (T1), a Pichia strain (T2), and of a fusion product of T2‐mutants (fp‐T2) have been examined in batch and continuous cultures with the single substrates xylose, acetate, glucose, mannose, and galactose or mixed substrates of them.

Maximum specific growth rate (μmax), substrate saturation constant (Ks), substrate inhibition (Ksi), yield (Y), dilution rate (D), and the protein content of the strains have been compared. The significance of the results for the production of single cell protein is pointed out.
Selective and rapid solubilization of the microbial membrane enzyme aldehyde dehydrogenase
Authors: Hommel R. , Kleber H.‐P.
Published: February 2007

An improved solubilization procedure for the membrane‐bound quinoprotein aldehyde dehydrogenase from Acetobacter rancens CCM 1774 was established. After the first solubilization of membrane enzymes by Brij 35 which provided important extraction of membrane proteins other than aldehyde dehydrogenase, the application of Trition X‐100 resulted in an almost 20‐fold purification of quinoprotein aldehyde dehydrogenase. The optimal solubilization was closely connected with definite detergent/protein ratios.
Regulation of the dnaQ gene of Escherichia coli in mutants expressing the SOS regulon constitutively
Authors: Quiñones Ariel
Published: February 2007

Current models for the mechanism of SOS mutagenesis in E. coli propose the involvement of a new or modified DNA polymerase III holoenzyme in error‐prone replicative bypass of bulky DNA lesions assuming an inhibited or excluded 3′ → 5′ proofreading exonuclease function of DNA polymerase. By promotor fusion to galK, gene fusion to lacZ and SI analysis the in vivo regulation of dnaQ coding the proofreading subunit of DNA polymerase III holoenzyme was analyzed under conditions of induced or constitutive SOS expression. The results presented here clearly show that, at least on the level of gene expression no regulatory event seems to contribute to the assumed decrease of proofreading activity during SOS mediated error‐prone bypassing of bulky lesions. On the contrary, an increase in dnaQ gene expression was observed following treatment with some SOS inducing agents which produces bulky DNA lesions.
Qualitative and quantitative changes in β‐1,4‐glucosidase accompanying growth of Aspergillus nidulans
Authors: Sharma S. , Bagga P. S. , Sandhu D. K.
Published: February 2007

A comparative study of the wild type A. nidulans and a mutant strain aco‐T69 (lacking conidia and cleistothecia) revealed the better production of β‐1,4‐glucosidase in the former. The relative distribution of the enzyme levels in various morphological structures viz. somatic hyphae, spores and cleistothecia also showed a variation. Highest specific activity was found in the cleistothecial extracts. The electrophoretic analysis of the wild type strain demonstrated the presence of three isoenzymes of β‐1,4‐glucosidase i.e. β‐GLU I, β‐GLU II and β‐GLU III, the number of which varies from one to three during the growth of the organism. The parallel study of the mutant strain showed complete absence of β‐GLU II. All three forms were present in the somatic hyphae and cleistothecial extracts while spore extracts depicted the absence of β‐GLU III in the wild type.
Sporothrix schenckii — a freeze‐fracture study
Authors: Svoboda Augustin , Trujillo‐Gonzalez Amanda
Published: February 2007

Freeze‐fracture electron microscopy of a pathogenic dimorphic fungus Sporothrix schenckii revealed planar views of cell structures corresponding to those described already on thin sections. In addition to the characteristic differences in cell wall thickness between conidia, yeast forms and filaments, variations in plasma membrane invaginations were found. In conidia the invaginations were short and abundant, while in yeast forms they were scarce and longer. The plasma membrane of the filaments was smooth without invaginations. No differences were found in the frequency of intramembrane particles among the three forms. In the region of the septal pore the particles were circularly arranged with a characteristic partitioning on the P and E fracture faces.
Lack of a correlation between the vitamin requirement and the ecological position of wood‐decay fungi
Authors: Gramss G.
Published: February 2007

Forty‐eight species of wood‐destroying basidiomycetous fungi which are represented by 74 strains were examined for their dependence on exogenous vitamin sources such as thiamine and biotin. In a series of up to 11 consecutive transfers to vitamin‐free glucose‐salt medium batches in a 4‐week rhythm it was shown that (i) the level of vitamin heterotrophy did not depend on whether the fungus was a parasite or a saprophyte, (ii) among both parasites and saprophytes vitamin‐independent and highly vitamin‐dependent isolates could be detected, (iii) almost 70% of the brown‐fungi, but only 30% of the white‐rot fungi dependend comparatively little on exogenous vitamin sources, (iv) the degree of vitamin heterotrophy varied in part dramatically among several strains of a given fungal species, (v) under permanent vitamin starvation none of the 74 fungal strains completely ceased growing, but several strains suffered an irreversible physiological collapse whose nature is still unknown. It is concluded that on natural timber resources both vitamin‐dependent and vitamin‐independent fungal strains can probably develop their normal pathovirulence and kratovirulence properties. Under conditions of vitamin starvation the equilibrium between the vitamin‐dependent decay fungus and the vitamin‐independent competitor may nevertheless become disturbed.
Steroid‐1‐dehydrogenases in nocardioform bacteria studied by electrophoresis and immuno blotting techniques
Authors: Kaufmann G. , Schumann G. , Wollweber L. , Hüller E. , Atrat P.
Published: February 2007

Fifteen nocardioform bacteria strains, capable of transforming steroid compounds were investigated with regard to their range of inducible steroid‐1‐dehydrogenase (St1DH)1 activities. The St1DHs of these bacteria were compared due to their immuno reactivity in Western blot experiments with a rabbit antiserum raised against the purified St1DH of Rhodococcus rhodochrous 7030. Four strains exhibited a strong immuno reactivity, irrespective of differences in the electrophoretic mobility of the enzymes. Fivestrains revealed significantly diminished reactivities, and in five strains with a very low St1DH content, no reactivity was found. One strain, designated as Nocardiaspec. 7151, exhibited a high, inducible St1DH activity, but no immuno reaction was found. The absence of immuno reactivity is discussed in connection with the considerably diminished electrophoretic mobility of this enzyme.
Construction of the dextrin‐degrading pof brewing yeast by protoplast fusion
Authors: Janderová Blanka , Cvrčková Fatima , Bendová Olga
Published: February 2007

A haploid, glucoamylase‐producing strain of Saccharomyces diastaticus lacking the POF gene and thus unable to produce phenolic off‐flavour in beer was constructed by classical genetic techniques. Protoplast fusion was performed between this strain and a brewing polyploid Saccharomyces uvarum strain. Some clones derived from fusion products can produce low‐carbohydrate beer of acceptable flavour.
L‐Carnitine uptake by Escherichia coli
Authors: Jung Heinrich , Jung Kirsten , Kleber Hans‐Peter
Published: February 2007

The uptake of L‐carnitine by Escherichia coli044 K 74 which is able to metabolize L‐carnitine to γ‐butyrobetaine under anaerobic conditions was studied. The uptake system of E. coli was induced in the presence of L‐carnitine or crotonobetaine. The optimum influx of L‐carnitine was found to take place at 37 °C in phosphate buffer, pH 7.5. On the basis of the temperature dependence of the uptake rate an activation energy of 53.5 kJ/mol was estimated. The transport of L‐carnitine was energy dependent. The kinetics of L‐carnitine entry followed the MICHAELIS‐MENTEN relationship yielding a Km value of 5.3 · 10‐4 M and a Vmax of 154 nmol/min · mg protein. The transport system showed considerable structural specifity for trimethylamine carboxylic molecules. The results suggest that E. coli possesses an inducible, active and carrier‐mediated uptake system for L‐carnitine.
Cyclic AMP‐dependent phosphorylation of fructose‐1,6‐bisphosphatase and other proteins in the yeast Candida maltosa
Authors: Hofmann K. H. , Polnisch E.
Published: February 2007

In crude extracts of Candida maltosa, about 12 proteins are phosphorylated in the presence of cAMP or of a catalytic subunit of cAMP‐dependent protein kinase.

A strongly labelled protein spot occurred in the position of fructose‐1,6‐bisphosphatase both after electrophoresis of crude extracts incubated with cAMP and of a partially purified fructose‐1,6‐bisphosphatase incubated with a catalytic subunit of cAMP‐dependent protein kinase. No phosphorylation of the cytoplasmic malate dehydrogenase could be detected.

From these results it was concluded that cAMP‐dependent phosphorylation plays an important role in the catabolite inactivation of fructose‐1,6‐bisphosphatase in Candida maltosa, as described for Saccharomyces cerecisiae.
Instability of in vitro resistance to imipenem in Pseudomonas aeruginosa
Authors: Wolter Ernst‐Jürgen , Witte Wolfgang
Published: February 2007

In 3 from 19 clinical isolates of Pseudomonas aeruginosa imipenem‐resistant subpopulations could be detected in vitro. In comparison to their wild strains these imipenem‐resistant cells were lacking an outer‐membrane‐protein of 50 kD. In the subpopulation derived from Pseudomonas aeruginosa 76 resistance to imipenem was found to be instable. It could be lost within a short period of time after subcultivation in the absence of imipenem. Cells with restored sensitivity to imipenem possess the outer membrane protein of 50 kD as the wild strain does.
Isolation and primary characterization of a new bacteriophage of obligate methylotrophic bacteria
Authors: Almumin Sabah , Kadri Mustafa , Mamat Uwe , Engel Joachim
Published: February 2007

Ø KISR 1, a new bacteriophage of obligate methylotrophic bacteria, was isolated from a local pilot plant. The phage belongs to the Podoviridae family of viruses characterized by a short non‐contractile tail and double‐stranded DNA. The size of phage genome was determined on the basis of electron micrographs and restriction enzyme analysis to be about 46 kb. The host range of Ø KISR 1 is restricted to three very closely related methanol‐utilizing KISR strains belonging to the genus Methylophilus. The phage does not originate from the methylotrophic KISR strains which were tested for lysogeny.
Regulation of ammonium assimilation by Clostridium acetobutylicum
Authors: Amine J. , Marczak R. , Maazouzi N. , Masion E.
Published: February 2007

Assimilation of ammonium by the obligate anaerobic bacterium Clostridium acetobutylicum was accomplished by the pathway: Glutamine synthetase/glutamate synthase. C. acetobutylicum also contained an asparagine synthetase, but no glutamate dehydrogenase activity was detected. The glutamine synthetase was partially repressed by addition of large amounts of ammonium chloride and/or casaminoacids to the medium, while the biosynthesis of the other enzymes was not regulated by the extracellular concentration of ammonium.
Selection of mutant Streptomyces strains with enhanced ability for acid precipitable polymeric lignin production
Authors: Antai S. P. , Iyo A. H.
Published: February 2007

Streptomyces viridosporus T7A spores were subjected to ultraviolet (UV) light mutagensis. Two mutant strains S. viridosporus T7A‐40 and T7A‐198 were isolated. These strains were grown on 5 g of sugar cane baggase lignocellulose and produced 36.0 mg and 41.4 mg of acid precipitable polymeric lignin (APPL) respectively as compared to 25.1 mg produced by the wild type after 8 weeks incubation at 37 °C. The quantities of APPL produced by the mutants represent 43.7% and 65.3% more APPLs than those produced by the wild type. Apart from the increase in APPL production, the observable effects of the ultraviolet light included; variation in spore pigmentation, induction of a brown diffusible pigment, production of hydrogen sulfide, loss of thermotolerance, lower cellulase activity and loss of inositol utilizing ability.
Evaluation of several rice varieties for horizontal resistance to leaf blast and neckrot (Pyricularia oryzae) in Ivory Coast
Authors: Awoderu V. A.
Published: February 2007

A number of rice varieties including local, exotic and differential varieties were exposed to natural infections in four ecological zones (Bouake, Man, Odienne and Tombokro) in Ivory Coast. Four international race types, belonging to three international race groups IA, IB and IF were detected. Two races were identified in race group IA and one race in each of the groups IB and IF. The race group IA identified in Odienne was found to be the most virulent. The local varieties Malouka, Gnonkonsoka, Toubabou, Nembeika Azi, Kotoouro, Itame, Gbahoma and some developed cultivars; ITA 257, ITA 235 and Farox 299, IAC 164 and IDSA 6 appeared to have put up stable resistance to Pyricularia oryzae.
Mycoflora associated with some freshwater plants collected from Delta region (Egypt)
Authors: Abdel‐Raouf  , Khallil M. A.
Published: February 2007

77 species and 3 species varieties belonging to 35 genera were isolated during this investigation. Five species namely: Chytriomyces annulus, Rhinocladiella schulzeri, Dactylella bemicodes, D. alaskana and D. rhompospora are new records to Egypt. The composition of water‐borne fungi was basically similar to those of the washwater of collected plants (phyllosphere) and plant part samples (phylloplane). Of the 20 zoosporic fungal species, Saprolegnia ferax and Dictyuchus sterilis were common in water samples; and Achlya oligacantha and S. ferax in washwater (phyllosphere). On glucose and cellulose‐CZAPEK's agar the most frequent of the three substrates were the members of Fusarium, Aspergillus, Cladosporium, Alternaria and Penicillium. Also many more species such as Alternaria alternata, Cladosporium cladosporioides, Fusarium moniliforme and Stachybotrys atra increased their frequency of occurrence and total counts on cellulose agar than was the case on glucose. Some fungal species were isolated only from water samples and not from phyllosphere or phylloplane and vice versa. Also, some fungal species were isolated on glucose and not on cellulose CZAPEK's agar medium and vice versa. The plant Ceratophyllum demersum exhibited the highest fungal counts while Phragmites communis exhibited the lowest counts. The water samples richer in fungal genera and species were those which were characterized by relatively high content of dissolved oxygen. pH, temperature and conductivity of collected water samples did not show any regular pattern and did not exhibit any considerable influence on fungal population.
Modification of immune response by coats of Myxococcus xanthus myxospores
Authors: Ruiz Concepción , Ramos‐Cormenzana Alberto
Published: February 2007

Treatment with coats of M. xanthus myxospores produced a marked modificatory effect on humoral response, depending on the inoculation model. Also we observed that the percentage of adherent phagocytes and phagocytic index were enhanced after treatment. These results were similar to the effect obtained by M. xanthus myxospores. Data showed that the immune response modifier properties of M. xanthus myxospores are principally present in the coats.
Ecological dynamics of marine luminous bacteria
Authors: Ramesh A. , Loganathan B. G. , Venkateswaran K.
Published: February 2007

Marine luminous bacteria are heterotrophic, Gram negative microorganisms which continuously emit light. Eight species of luminous bacteria have been described belonging to three different genera, viz. Photobacterium, Vibrio and Alteromonas. In this review we report on the distribution of luminous procaryotes in abiotic and biotic components of the marine environment and the interactions among them.
The virulent bacteriophage IRA of Salmonella typhimurium: Cloning of phage genes which are potentially lethal for the host cell
Authors: Adamia Revaz S. , Matitashvili Elvina A. , Kvachadze Leila I. , Korinteli Vladimer I. , Matoyan Diana A. , Kutateladze Mzia I. , Chanishvili Teimuraz G.
Published: February 2007

Morphological and biological properties of Salmonella typhimurium phage IRA were studied. The phage is a member of the Styloviridae family and exhibits a very wide spectrum of lytic activity.

Molecular cloning of phage genes whose expression is lethal for the host cell has been performed and consequences of gene expression have been investigated. Expression of recombinant plasmid pKI71 causes structural changes of the cell wall and also degradation of host DNA while plasmid DNA remains intact. Expression of pKI72 blocks normal cell division. The possibility of applying such recombinant clones in marking pathways of microbial contamination in water areas is proposed.
Production and control of extracellular α‐amylase in Micrococcus varians
Authors: Adeleye Adeyemi I.
Published: February 2007

An extracellular α‐amylase was induced in cultures of Micrococcus varians during growth in a liquid medium containing starch as sole carbon source. Synthesis of this enzyme was repressed by the addition of glucose or fructose to starch metabolizing cells and was induced in a glucose or fructose metabolizing culture by the addition of starch.

Glycine was found to enhance growth and production of α‐amylase while the least growth and enzyme activity was recorded in medium containing ammonium sulphate as nitrogen source.
Einsatz der Fermenter‐Dialysekultur zur Kultivierung medizinisch relevanter Erreger III. Candida albicans
Authors: Pfüuller Roland , Mehl Michael , Starke Roland , Hentschel Christian , Grunow Roland , Schmidt Gerhard , Baehr Rüdiger Von
Published: February 2007

For mass cultivation of Candida albicans (serotyp A), a fermenter dialysis culture technique is described and compared with shaking culture and fermenter batch culture techniques.

Important growth parameters such as yeast dry weight and viable cell counts demonstrate the advantage of the fermenter dialysis culture.

Mannan. the major antigen from Candida albicans prepared by phenol‐water extraction followed by gel chromatography was tested with the monoclonal IgM antibody H5.
Diversity of micro‐fungi in an Antarctic dry valley
Authors: Baublis Joseph A. , Wharton Robert A. , Volz Paul A.
Published: February 2007

The fungal microflora of a dry valley in southern Victoria Land near McMurdo Sound, Antarctica, was investigated. Samples were collected from introduced objects such as a mummified penguin and spent chewing tobacco in addition to the sparse soil found in rock fissures, isolated moss colonies, shoreline deposit materials, CaCO3precipitates, and microbial mat debris obtained from the frozen surface of the lake in the basin of Taylor Valley. Using conventional media and techniques, all collection sites yielded populations of yeasts and filamentous fungi. Water samples and live microbial mats from beneath the lake ice yielded species of fungi along with an abundance of bacteria.
Glucans in the mycelium of Aspergillus giganteus mut. alba: Alkali‐soluble glucans
Authors: Fiema J. , Zurzycka A. , Bruneteau M.
Published: February 2007

From the mycelia of Aspergillus giganteus mut. alba grown in light and darkness two fractions of glucans were extracted. One of them was purified and characterized by its alkali‐solubility and enzymatic degradation as polymer of β‐d‐glucose.
Growth inhibition of some phytopathogenic fungi by organic extracts from Nigrospora oryzae (Berkeley and Broome) Petch
Authors: Szewczuk V. , Kita W. , Jarosz B. , Truszkowska W. , Siewiński A.
Published: February 2007

Aqueous solutions of organic extracts of Nigrospora oryzae in the concentration range 0.1 to 1000 μg/cm3 were found to inhibit both spore germination and mycelium growth of Fusarium avenaceum, F. culmorum, F. gramminearum, F. gramminearum, F. oxysporum, F. equiseti, F. lateritium and Botrytis cinerea.
Phyllosphere and phylloplane fungi of qat in Sana'a, Yemen Arab Republic
Authors: Alhubaishi A. A. A. , Abdel‐Kader M. I. A.
Published: February 2007

Eighty six species belonging to thirty one genera were collected from the qat phyllosphere (30 genera and 78 species) and phylloplane (20 genera and 64 species) of 24 varieties tested. In the phyllosphere the most frequent genera were Cladosporium, Aspergillus and Alternaria followed by Penicillium, Drechslera, Fusarium, Curvularia, Phoma and Chaetomium. From the preceding genera the most prevalent species were C. herbarum, C. macrocarpum, A. niger, A. flavus, A. alternata, A. phragmospora, P. citrinum, P. notatum, D. spicifera, D. halodes, D. hawaiiensis, F. oxysporum, F. moniliforme, C. lunata, P. humicola, P. herbarum and C. globosum. In the phylloplane the order of genera frequency was more or less the same, while the most common species were C. herbarum, C. sphaerospermum, A. niger, A. flavus, A. alternata and A. tenuissima.
“Definitive senescence” in stock cultures of basidiomycetous wood‐decay fungi
Authors: Gramss G.
Published: February 2007

For 7 cultures of basidiomycetous wood‐decay fungi the decline of the following vitality marks were recorded over a 6‐year period: (i) Consumption of sterilized beech wood substrate within a time unit as an indicator of the overall vigorousness of the fungus, (ii) decline of the competitive saprophytic ability (kratovirulence), which enables the fungus to colonize natural nonsterile substrates, (iii) capacity for sexual reproduction, (iv) several morphological features of the fungal colony. The reference strains kept growing at + 1 … 2°C on fertilized wood dust substrate retained in 5 of 7 cases all of their juvenility marks, although the wood‐decay capacity gradually dropped back to 65 to 34% that of the initial value. The substrains maintained on liquid still cultures at 23°C lost their vitality marks after a period of continuous decline rather abruptly. With the loss of kratovirulence and fruiting capacity the strains were no longer viable under field conditions, and with the drop of the sterile wood‐decay capacity to less than 3% by dry weight the formation of aerial mycelium and melanin pigments virtually ceased. In several fungal species the colonies segregated into coexisting sectors of extreme senescence and comparative juvenility, and a spread of senescence to the juvenile sectors did not occur. It is concluded that stock cultures of wood‐decay fungi are subject to progressive senescence even under optimum conditions of strain preservation. Their current vitality should be examined in a sterile wood decay test before they are used in biotechnology or research.
Appearance of senescent sectors in the ageing vegetative thallus of several basidiomycetous fungi held in pure culture
Authors: Gramss G.
Published: February 2007

The initially juvenile stock cultures of basidiomycetous wood‐decay fungi lose most of their physiological performances during long‐term storage in axenic culture. In order to link the rapidity of this debilitation or senescence process with the properties of the fungal genome, both a juvenile strain of Bjerkandera adusta (Bjerad 2S3) and a pre‐aged strain of Hypholoma sublateritium (Ns 1) were transferred to 7 identical round flasks with a liquid still culture medium and maintained at 23°C. In a 6‐month rhythm the disappearance of several juvenility marks among the 7 isogenic subcultures was recorded and compared with the vitality status of the 2°C maintained reference strains. Within 26 to 30 months of observation, the 7 isogenic subcultures of Bjerad 2S3 as well as Ns 1 aged at a strikingly different speed. Both mycelial thalli segregated into coexisting sectors of progressive senescence and relative juvenility. The isogenic subcultures dominated by juvenile sectors displayed dramatically longer life spans than did the subcultures dominated by the senescent mycelial sectors. This means that initially isogenic parts of a mycelial thallus have a strikingly different life expectancy. In the slow‐ageing subcultures of Ns 1, neither the senescent nor the juvenile sector were able to overgrow and infect the colony of their coexisting conterpart. The preconditions are discussed that could possibly prevent the spread of the carriers of senescence into the juvenile mycelial parts.
Aeromonas hydrophila: Variability in biochemical characteristics of environmental isolates
Authors: Okpokwasili Gideon C.
Published: February 2007

A total of 161 strains, including 144 aeromonads, of which 100 had been isolated from water and sediment samples from the Chesapeake Bay, five clinical and 33 Anacostia River isolates of Aeromonas hydrophila, six Aeromonas sobria, and ten reference cultures were examined in a numerical taxonomy study in which each of the strains were examined for 56 unit characters. Similarity between strains was computed using the simple matching (SSM) and Jaccard (SJ) coefficients. The strains were clustered by unweighted average linkage and single linkage algorithms. Results of all analyses yielded similar clusterings of strains. Of the 161 strains included in the study, 148 were recovered in seven major clusters. A large cluster of Aeromonas hydrophila yielded two sub‐clusters. From the results of the taxonomic analysis it is concluded that several biovars of Aeromonas hydrophila can be isolated from the aquatic environment, but geographical or site specific distribution of the biovars could not be detected.
Beeinflussung der intrazellulären cAMP‐ und cGMP‐Konzentration im Hefewildstamm und in ausgewählten Mutanten von Saccharomyces cerevisiae als Regulationsmodell für höhere Eukaryoten
Authors: Sachse O.
Published: February 2007

The addition of d(+)‐glucose (final concentration 50 mm) to a cell suspension of yeasts (wild type and several mutants of the cell cycle, the cAMP‐dependent protein kinase system, and a mutant of the adenylate cyclase gene) triggers a rapid increase in the concentrations of cAMP and cGMP in the wild strain. In contrast to cAMP, an increase of cGMP was also found in the mutants.

cAMP and cGMP have been characterized as second messengers in eucaryotic cells. Cyclic nucleotide activation of the protein kinases enables them to perform their only known function in eukaryotes, the phosphorylation of substrate proteins.

The results, described here by using selected yeast mutants as a model for higher eukaryotes, indicate that there exist two different regulatory systems for the control of the cAMP and cGMP levels.
Effect of glucose and citrate on α‐amylase production in Bacillus licheniformis
Authors: Tonkova Alexandra
Published: February 2007

Studies on the α‐amylase synthesis were carried out with two strains of Bacillus licheniformis: a mutant strain 44MB82 and its selected variant 44MB82‐G. The cells were cultivated in a nutrient medium containing glucose or citrate as a carbon source. The results obtained indicated that α‐amylase was produced in both strains without inducers in the medium. The variant strain 44MB82‐G, which synthesized α‐amylase in the presence of 6% glucose, showed 58‐fold increased α‐amylase activity compared to strain 44MB82 grown in the presence of 2% glucose. When cells of both strains were cultivated in a medium with 1% citrate, α‐amylase activity of the variant strain was 5 times higher than that of strain 44MB82. The effects of starch and ATP on α‐amylase synthesis are also discussed.
Biosynthese der Anthracycline: eine Neuinterpretation der Ergebnisse zur Daunomycin‐Biosynthese
Authors: Wagner Christina , Eckardt Klaus , Ihn Wolfgang , Schumann Gisbert , Stengel Cornelia , Fleck Werner F. , Tresselt Dieter
Published: February 2007

On the basis of literature data and our own experiments the “late” biosynthetic pathway to daunomycin has been interpreted from a new point of view considering both thein vivobiosynthesis and formation of shunt products. In contrast to existing hypotheses proposed by other authors we discuss a modified sequence leading to C‐11 oxidation and, as a consequence, understand ϵ‐rhodomycinone as a shunt product instead of a biosynthetic intermediate.

In addition, a new hypothesis about the “early” steps of the ring formation from polyketides by a sequence of enzyme reactions has been proposed.
Characterization of isocitrate lyase from the yeast Yarrowia lipolytica
Authors: Hönes I. , Simon M. , Weber H.
Published: February 2007

The active form of isocitrate lyase (ICL) from the yeast Yarrowia lipolytica was eluted as single peak from ion exchange on DEAE‐cellulose. The enzyme had a specific activity of 7.4 U/mg. Its molecular mass was estimated to be approximately 200 to 210 kDa by gel filtration chomatography on Sephadex G 200. In SDS‐polyacrylamide gel electrophoresis the enzyme was characterized by an unique protein band of about 50 kDa, thus indicating that ICL is a tetramer of identical subunits. The optimum pH was 6.0 in 50 mm phosphate buffer at 30°C. The Km value of the 35‐fold purified ICL for threo‐ds‐isocitrate in 50 mm phosphate buffer at pH 6.0 was 0.3 mm. In regulation studies ICL was found to be noncompetitive inhibited by succinate and oxaloacetate.

Antibodies against ICL were raised in rabbits. The specificity of the anti‐ICL‐antibodies was estimated by Ouchterlony tests and by a competitive ELISA on microtiter plates.
Cytobiochemical characterization ofAspergillus terreus17p utilizing various carbon substrates
Authors: Lusta Konstantin A. , Sysoev Oleg V. , Sharyshev Andrei A.
Published: February 2007

The thermotolerant mycelial fungus,Aspergillus terreus17p, was shown to be capable of utilizing various carbon substrates, e.g., cellulose, glucose, hexadecane, methanol. In all cases the fungal hyphae cytoplasm contained microbodies differing in morphology with a carbon source. A cytochemical reaction with 3,3‐diaminobenzidine revealed catalase within microbodies. A comparative enzymatic analysis was carried out for cell‐free extract from fungi grown on various carbon substrates. The activities of the enzymes (alcohol oxidase, formaldehyde‐ and formate dehydrogenases, dihydroxyacetone synthase and dihydroxyacetone kinase) catalyzing methanol dissimilation and assimilation were estimated in the methanol‐grown mycelium. Maximum values of hexokinase and glucose‐6‐phosphate dehydrogenase activities were observed in hyphae cultivated with glucose and cellulose. Synthesis of cytochrome P‐450 and oxidase of higher fatty alcohols involved inn‐alkane dissimilation is induced by hexadecane. Activities of the citric acid cycle enzymes, fumarase and isocitrate dehydrogenase, were not essentially influenced by the nature of carbon substrates.
Influence of sugars on the activity of cellulase system from two basidiomycetes cultures
Authors: Nigam Poonam , Prabhu K. A.
Published: February 2007

Influence of some sugars was studied on activity of purified cellulase enzymes produced by two white‐rot basidiomycetes cultures in submerged fermentation. Exo‐ and endo‐glucanases were found to be stimulated by glucose, sucrose and xylose, but β‐glucosidase was inhibited by all sugars tested except sucrose being neutral. Cellobiose severely inhibited all three cellulase activities at all three concentrations taken in reaction mixture.
Effect of cultural factors on cellulase biosynthesis in submerged bagasse fermentation by basidiomycetes cultures
Authors: Nigam Poonam , Prabhu K. A.
Published: February 2007

Isolates of basidiomycetes have been studied for the production of extracellular cellulases in submerged shaken cultures using whole sugar cane bagasse (without delignification) as substrate. Cultures produced maximum exo‐β‐1,4,glucanase (FPD), endo‐β‐1,4,glucanase (E.C.3.2.1.4.) (CMCase) on the 4–5th day and β‐glucosidase (salicinase) (E.C.3.2.1.21.) on the 6th day of fermentation. Production of these enzymes could be manipulated for maximum yields by implication of selected cultural factors like growth medium, incubation condition, pH of fermentation, particle size of bagasse and various additives.
Heterotrophic carbon dioxide fixation by a methylotrophic Ancylobacter species
Authors: Müller‐Kraft Gabriele , Uhlenhut Joachim , Babel Wolfgang
Published: February 2007

In an Ancylobacter species an acetyl‐CoA‐activated phosphoenolpyruvate carboxylase was found. The specific activity in methylotrophic growth (26 nmol min−1 mg−1) is greater than in heterotrophic nutrition (10 nmol min−1 mg−1). Pyruvate carboxylase could not be detected either in methanol‐ or in glucose‐grown cells.
Immunogold labelling of human IFNα2 and an IFNα1/α2 hybrid produced by recombinant Escherichia coli
Authors: Breitling Reinhard , Wagner Barbara , Wagner Manfred , Gase Klaus , Behnke Detlev
Published: February 2007

In recombinant Escherichia coli strains the subcellular location of human interferon (IFN)α2 and a hybrid IFNα1/α2 was investigated by immunogold labelling techniques. The gold label was scattered throughout the cytoplasm in cells containing the gene for mature IFNα2 under the control of heterologous staphylokinase sak42D transcription and translation initiation signals. In contrast, in cells containing in addition the sak42D signal peptide coding region in front of the IFN gene, the gold label was found mainly near the cell membrane and in the periplasmic space. Inclusion bodies were identified in cells accumulating IFN in the cytoplasm.
Nucleotide sequence of a variant protein A of Staphylococcus aureus suggests molecular heterogeneity among strains
Authors: Brígido Marcelo De Macedo , Barardi Célia Regina Monte , Bonjardin Claudio A. , Santos Cecília Luiza Simões , Junqueira Maria De Lourdes , Brentani Ricardo Renzo
Published: February 2007

Protein A is a cell wall linked protein of Staphylococcus aureus that binds mammalian IgG. Although protein A displays high size heterogeneity among strains, cloning and sequencing of its gene from two strains had not shown a large difference in size. Here we report a third protein A gene sequence that shows a size variation relative to these two, due to deletions on both one IgG binding domain and a cell wall binding domain (region X). By analysis of the three sequences we were able to delineate a hypothetic model for region X domain evolution and discussed the origin of genetic variability within and without strains.
Determination of cytochrome P‐450 in Cunninghamella elegans intact protoplasts and cell‐free preparations capable of steroid hydroxylation
Authors: Dlugoński Jerzy , Bartnicka Katarzyna , Zemelko Iwona , Chojecka Violetta , Sedlaczek Leon
Published: February 2007

Cytochrome P‐450 was shown to be involved in 11α‐, and 11β‐hydroxylation of Substance S in intact C. elegans protoplasts. The steroid transformation was inhibited by carbon monoxide, the inhibitory effect being dependent on CO concentration. The function of cyt P‐450 in intact protoplasts was confirmed by the estimation of strong absorption at 450 nm in the CO difference spectrum. The presence of antimycin A was necessary to prevent the reduction of the cytochrome oxidase and its interference with the cyt P‐450 in the spectrophotometric analysis.

The intracellular content of cyt P‐450 could be increased from 5.25 pm/mg protein to 26.88 pm/mg protein when the steroid inducer was present in the medium at each stage of protoplast preparation and during cyt P‐450 determination.

The enriched microsomal fraction obtained from the crude extract of ruptured protoplasts contained the steroid 11α‐hydroxylase system of C. elegans. The activity of 11β‐hydroxylase could not be detected under the conditions of the experiment. The localization of steroid hydroxylases of C. elegans in microsomes was confirmed by cyt P‐450 detection in the 9600 × g supernatant. Membranous fractions (pellets 1100 × g and 9600 × g) of the concanavaline A stabilized protoplasts, carrying the marker plasma‐membrane‐bound and mitochondrial ATPases, did not show maximum absorption at 450 nm in the CO difference spectrum.
Anthracyclinone‐blue A and B, new natural anthracyclinones containing nitrogen in the molecules: Isolation, chemical structures and biosynthesis
Authors: Eckardt K. , Tresselt D. , Ihn W. , Schumann G. , Eritt I. , Sedmera P. , Novák J.
Published: February 2007

Two new anthracyclinones, 7‐(2‐hydroxyethylamino)bisanhydroaklavinone and 7‐(2‐hydroxyethylamino)bisanhydro‐ϵ‐rhodomycinone, were isolated from fermentations of the blocked mutants S. galilaeus S 383 and S. griseus ZIMET 43707, respectively. The new compounds have been designated as anthracyclinone‐blue A and B because of their characteristic deep‐blue colour. Feeding experiments suggest that anthracyclinone‐blue A and 7‐hydroxy‐bisanhydroaklavinone, a minor component of strain S 383, are shunt products originating from aklaviketone.
Proteases of psychrotrophic bacteria isolated from glaciers
Authors: Margesin Rosa , Palma Norbert , Knauseder Franz , Schinner Franz
Published: February 2007

25 psychrotrophic protease‐forming bacteria isolated from glaciers were identified as follows: Pseudomonas spp. (18 strains), Flavobacterium spp. (3 strains), Xanthomonas maltophilia (2 strains), Aeromonas hydrophila (1 strain) and Bacillus sp. (1 strain). Characteristics of proteolytic activity in cell‐free culture supernatants were studied. Proteases produced by 40% of the bacteria showed a maximum azocaseinolytic activity around 40°C and pH 7. Enzymes were rapidly inactivated after heating at 50°C. pI‐values of proteases ranged from > 9.5 to 7.0. Sensitivity to EDTA indicates that most proteases are metalloproteases. Proteases of psychrotrophs could be differentiated from proteases of mesophiles by a lower temperature optimum, a lower activation energy and a higher sensitivity against heat treatment.
In vivo utilization of N‐(phosphonomethyl)‐anilines and related substances by Pseudomonas spec. GS
Authors: Albrecht Birgit , Weidhase Rosemarie , Stock Manfred , Weidhase Reinhard Albrecht
Published: February 2007

Utilization of various phosphonates as source for phosphorus by the glyphosate degrading strain Pseudomonas spec. GS was investigated. Metabolites of phosphonate degradation were characterized indicating the cleavage of the C—P‐bond as primary step of breakdown.

The phosphonate N‐(phosphonomethyl)‐4′‐nitroazobenzene‐4‐amine (azophon) was characterized as a suitable substrate for detection of C—P‐bond splitting activity in vivo.

Pseudomonas cells permeabilized by toluene treatment were also capable of phosphonate degradation whereas no in vitro activity of a putative C—P‐bond cleaving enzyme was detectable after cell disruption.
Two‐dimensional polyacrylamide gel electrophoresis of proteins synthesized during early germination of Bacillus subtilis 168 in the presence of actinomycin D
Authors: Hirano Yoshiro , Matsuda Motoo , Kameyama Tadanori
Published: February 2007

Two‐dimensional gel electrophoresis was used to demonstrate the synthesis of approximately 65 [35S]‐methionine‐labelled soluble proteins between 0 and 10 min after the start of germination, of approximately 210 proteins at 10–20 min, and of approximately 260 proteins during vegetative growth of Bacillus subtilis. When actinomycin d and [35S]‐methionine were administered at the onset of germination and the proteins synthesized during the subsequent 15 imn were analyzed, two proteins were detected, and were designated protein I and protein II. Immunoblot analysis with an antiserum raised against RNA polymerase from Escherichia coli demonstrated that protein II corresponded to the σA factor of Bacillus subtilis. Thus, the σA facter is synthesized during early germination of Bacillus subtilis in the presence of actinomycin D.
Application of immobilized cells for biotransformations of steroids
Authors: Schmauder H.‐P. , Schlosser D. , Günther T. , Hattenbach A. , Sauerstein J. , Jungnickel F. , Augsten H.
Published: February 2007

A survey is given of possible solutions and open‐ended questions in the biotransformation of steroids (without side chain degradation of sterols) by using immobilized cells. The data of literature between 1975 and 1990 and results of preliminary experiments from the microbial, biochemical, biophysical, physiological, as well as the biotechnological point of view are summarized and discussed.
Utilization of 1,3,5‐trihydroxybenzene (phloroglucinol) by a soil isolate, Rhodococcus species BPG‐8
Authors: Armstrong Stephen , Patel Thakor R.
Published: February 2007

A Gram‐positive bacterial strain was isolated from oil rich soil in Newfoundland and found to utilize various di‐ and trihydroxylated aromatic compounds as a source of carbon and energy. This bacterium exhibited rod/coccus dimorphism during its growth cycle. Chemical analysis of cell wall composition (amino acids, sugars, and fatty acids) was performed using gas chromatography‐mass spectrophotometry and high pressure liquid chromatography. Comparison of both acid production and growth substrates showed complete homology with Rhodococcus erythropolis. Growth of the isolate on phloroglucinol (1,3,5 trihydroxybenzene) occurred in the pH range 5–8; with a substrate and temperature optima of 8.0 mM and 25 °C. The oxidation of PG was examined using whole cells as well as crude cell extracts. PG oxidation was shown to be due to an inducible enzyme system. Tentatively the isolate was identified as Rhodococcus species BPG‐8 which is able to utilize phloroglucinol as the sole source of carbon and energy.
The N‐terminal amino acid sequences of Brevibacterium sp. R312 nitrile hydratase
Authors: Duran R. , Chion C. K. N. Chan Kwo , Bigey F. , Arnaud A. , Galzy P.
Published: February 2007

Nitrile hydratase from Brevibacterium sp. R312 was purified to homogeneity. The isoelectric point was 5.75. The two kinds of subunits were separated by reverse phase HPLC and their N‐terminal amino acid sequences were found to be identical to those of Rhodococcus sp. N‐774 nitrile hydratase.
Taxonomic relationship of some members of Azotobacteraceae based on their protein profiles
Authors: Jana Subhas Chandra , Chakrabartty Pran Krishna , Mishra Ajit Kumar
Published: February 2007

Analysis of protein profiles of the members of Azotobacteraceae suggests that the genus Azotobacter consists of a heterogeneous group of bacteria, of which Azotobacter beijerinckii should possibly be separated to a new genus. Azomonas agilis and Azomonas macrocytogenes are only 26 percent related to each other.
Potassium leakage from Escherichia coli cells treated by organic ammonium salts
Authors: Mlynarčík Dušan , Sirotková Libuša , Devínsky Ferdinand , Masárová Ľubomíra , Pikulíková Aurélia , Lacko Ivan
Published: February 2007

The effect of the homologous series of 1,1‐dialkylpiperidinium bromides on the potassium leakage from Escherichia coli cells has been studied. The minimum concentration for each compound which is able to release maximum of cellular potassium has been determined and correlated with the inhibitory activities of the compounds. The relationship between the structure and the activity enables to consider the K+ leakage as the marker of inhibitory activity of the membrane active antimicrobials.
Utilization of organic acids and amino acids by species of the genus Bacillus: A useful means in taxonomy
Authors: Nagel Matthias , Andreesen Jan R.
Published: February 2007

The type strains of 26 Bacillus species were investigated with respect to their capabilily to utilize 48 organic acids and 20 amino acids by using phenol red indicator plates and an amino acid analyzer, respectively. In addition, strains of Bacillus sphaericus were found to utilize many organic acids and amino acids in contrast to carbohydrates which are routinely checked. The results obtained indicated an individual utilization pattern for every species investigated, pointing to a useful taxonomic application of these tests for the genus Bacillus.
Isolation, identification and germination of spores of Thermoactinomyces from Qatari soils (Arabian Gulf)
Authors: Shoreit Ahmed A. M.
Published: February 2007

40 isolates of Thermoactinomyces were isolated from Qatari soils and identified as T. vulgaris (26 isolates), T. thalpophilus (8), T. putidus (4) and T. sacchari (2). The total count of this genus increased concomitantly with the increase of organic matter in soil samples. The effect of temperature, pH and composition of medium on the germination of spores of T. vulgaris were examined by measuring the reduction of turbidity of spore suspensions. Optimal germination took place at 55 °C, at a pH range of 7.5 to 8.5 and in phosphate buffer (10 mM) plus L‐alanine, L‐leucine and L‐phenylalanine (1 mM).
Metabolic blocks in the degradation of β‐sitosterol by a plasmid‐cured strain of Arthrobacter oxydans
Authors: Dutta Ranjit K. , Roy Monoj K. , Singh H. Devendra
Published: February 2007

Plasmid‐harbouring, sterol‐decomposing organism Arthrobacter oxydans 317 was treated with sodium dodecylsulphate to obtain a plasmid‐cured strain A. oxydans 317 A1 incapable of utilizing 4‐androstene‐3,17‐dione (AD). The strain 317 Al was unable to degrade β‐sitosterol side chain completely to form AD but could carry out partial degradation as shown by the accumulation of 3‐oxochol‐4‐en‐24‐oic acid as a major metabolite and 27‐norcholest‐4‐en‐3,24‐dione as a minor metabolite. The strain could form 1,4‐androstadiene‐3,17‐dione (ADD) from 3‐oxo‐23,24‐bisnorchol‐1,4‐dien‐22‐oic acid (BNC) to a limited extent. The existence of metabolic blocks in the conversion of 3‐oxochol‐4‐en‐24‐oic acid to 3‐oxo‐23,24‐bis‐norchol‐4‐en‐22‐oic acid and further conversion to AD by the plasmid‐cured strain 317 Al was suggested. Neither the formation of ADD from AD nor the conversion of AD and ADD to 9α‐hydroxy derivatives leading to steroid ring opening could be done by the plasmid‐cured strain but the 17β‐reduction of AD and ADD and 1(2)‐reduction of ADD were not affected by the absence of the plasmid. It was proposed that plasmid determines 1(2)‐dehydrogenation and 9α‐hydroxylation of steroid ring structure in this organism.