bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selection of mutant Streptomyces strains with enhanced ability for acid precipitable polymeric lignin production
Authors: Antai S. P. , Iyo A. H. 
Published: February 2007

AbstractStreptomyces 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

AbstractA 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

Abstract77 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

AbstractTreatment 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

AbstractMarine 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

AbstractMorphological 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

AbstractAn 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

AbstractThe 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

AbstractFrom 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

AbstractAqueous 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

AbstractEighty 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

AbstractFor 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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractStudies 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

AbstractOn 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

AbstractThe 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

AbstractThe 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

AbstractInfluence 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

AbstractIsolates 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

AbstractIn 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

AbstractIn 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

AbstractProtein 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.