bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some ecological and physiological studies on bacteria isolated from salt‐affected soils of Egypt
Authors: Zahran H. H. , Moharram A. M. , Mohammad H. A. 
Published: February 2007

AbstractMembers of Bacillaceae, Rhizobiaceae, actinomycetes and others were isolated from cultivated and non‐cultivated saline soils. The high population of bacteria and actinomycetes were almost coincided with the relatively high levels of organic matter whatever the degree of soil salinity. Bacillus stearothermophilus and B. subtilis were more frequently isolated than other Bacillus species. Most of Rhizobium isolates were salt tolerant being able to grow in media containing 3% and 6% NaCl. The abilities of different bacterial isolates to attack citrus pectin, soluble and insoluble forms of cellulose were also tested.
Microbial degradation of aquatic biomass by Trichoderma viride 992 and Aspergillus wentii 669 with reference to the physical structure
Authors: Kour J. , Maheshwari D. K. , Mehta P. 
Published: February 2007

AbstractThere was a considerable change in the structural parameters of both the lignocellulosic substrates. This change was confirmed by infrared (IR) spectroscopy and X‐ray diffraction data, which reveled the presence of phenolic groups in the peaks range 1310–1410 and 1200 cm−1 with large crystalline substrates. These were found to be reduced after treatment with alkali. Enzyme/s activity were found to increased after pretreatment of hydrolysed substrates. The structural modification in both the substrates were further evidenced by the results obtained after enzymatic hydrolysis of alkali‐treated substrates.
Fructose‐2,6‐bisphosphate level and β‐lactam formation in Penicillium chrysogenum
Authors: Kozma József , Bartók Gábor , Szentirmai Attila 
Published: February 2007

AbstractThe rate of penicillin formation in the medium containing lactose as sole carbon source markedly decreased after addition of glucose but at the same time the growth rate of fungal mycelium increased. Significant correlation was found between the formation of penicillin and the intracellular concentration of fructose‐2,6‐bisphosphate. It appears that penicillin production is influenced by the level of fructose‐2,6‐bisphosphate.
Variation in poly‐β‐hydroxybutyrate synthesis in rhizobia reflects strain differentiation and temperature regulation
Authors: Nair Suresh , Jha Prakash K. , Babu C. R. 
Published: February 2007

AbstractPolyβ‐hydroxybutyrate (PHB), a carbon storage polymer, occurs widely among prokaryotes including Rhizobium. Screening of 45 strains of rhizobia, isolated from nodules of legumes inhabiting different ecological regimes, showed a wide range of variation in the PHB content. Broadly, this variation is strain‐ specific and may be used as a taxonomic character for strain differentiation. Rhizobia show minimum PHB content at optimum temperature for growth and relatively higher content at the temperature extremes implying that PHB accumulation in rhizobia is in response to stress imposed by the extremes of temperature. PHB presumably protects membrane structure of rhizobia during this stress.
Regulation of glutamate metabolism in the cyanobiont Nostoc ANTH by nitrogen sources
Authors: Singh Surendra 
Published: February 2007

AbstractGrowth, heterocyst differentiation, nitrogenase activity and glutamate uptake were studied in the cyanobiont Nostoc ANTH, a free‐living isolate of the liverwort Anthoceros punctatus. Nostoc ANTH grew well in N2‐medium and produced heterocyst and nitrogenase activity whereas NO‐ and NH‐grown cultures did not show heterocyst differentiation and nitrogenase activity. Also, glutamate inhibited the diazotrophic growth, heterocyst differentiation and nitrogenase activity. However, the availability of NO and NH to the glutamate‐medium resulted in the recovery of growth. NO‐ and NH‐grown cells showed reduced levels of glutamate uptake which further reduced by the supplementation of NO‐ and NH in the reaction mixture during experimentation. These results suggest that in Nostoc ANTH glutamate acts as an inhibitor of heterocyst differentiation and nitrogenase activity rather than as a nitrogen source and that availability of NO‐ and NH alleviates the glutamate toxicity by inhibiting its uptake. This glutamate toxicity may be the reason for the localization of glutamate forming enzyme, glutamate synthase (GOGAT) within vegetative cells and not within heterocysts.
Steroid metabolism with intestinal microorganisms
Authors: Groh Helmut , Schade Karin , Hörhold‐Schubert Cläre 
Published: February 2007

AbstractAs a result of the metabolic activities of numerous anaerobic microorganisms with sterols, bile acids and steroid hormones as substrates in connection with the enterohepatic circulation of these compounds, the intestine may be considered as an “endocrine” active site or organ.The review summarizes transformations of steroids by anaerobic intestinal bacteria, the physiological and supposed pathophysiological meaning thereof. The aim is to recommend further investigation in this field with respect to both the elucidation of the reactions and biological responses.
Discrimination from other thermophilic Campylobacter and genometyping at the chromosomal genomic DNA level of Campylobacter lari
Authors: Matsuda Motoo 
Published: February 2007

AbstractSince the respective undigested and intact chromosomal DNAs from C. coli JCM2529T, from two strains of C. coli, C. jejuni JCM2013 and from two strains of C. jejuni migrated as fragments of around 1,900 kb and the chromosomal DNAs from C. lari JCM2530T and from eleven strains of C. lari migrated as fragments of around 1,640 kb, pulsed‐field gel electrophoresis (PFGE) was clearly demonstrated to be useful for the discrimination of C. lari from two other thermophilic species of Campylobacter (C. coli and C. jejuni). PFGE revealed that SmaI generated nine distinctly different and distinguishable banding profiles from the DNA of 18 strains of C. lari, which included the type strain. Three types of banding profile, namely, A, B and C, exemplified by the nine profiles included those from five, four and three strains of C. lari, respectively. Our present attempt to discriminate and to genome‐type C. lari at the chromosomal genomic level using PFGE and SmaI may be a valuable step towards a discriminative and molecular‐epidemiologic study of C. lari.
Infection of reovirus type 3 in Mongolian gerbils (Meriones unguiculatus) – Lesions in pancreas and brain
Authors: Yukawa M. , Takeuchi T. , Mochizuki K. , Inaba Y. , Kamata H. , Onodera T. 
Published: February 2007

AbstractGerbils were inoculated with reovirus type 3 (Abney strain), and the pancreas, brain and other organs histopathologically evaluated.Male Mongolian gerbils (Meriones unguiculatus) aged 5‐10 days (newborn, 9 animals), 4 weeks (juvenile, 5 animals), and 12 weeks (adult, 5 animals) were used. Gerbils inoculated intraperitoneally with the virus were sacrificed 3, 5, 7, or 10 days later. Tissues were observed by light and electron microscopy.The pancreas of newborns showed inflammatory edema with infiltrates of neutrophilis and mononuclear round cells, degranulation of acinar cells and dissociation of lobules and acini with necrosis at 3 days or later after inoculation but not degeneration of pancreatic islets. Brains of newborns had necrosis of neurons and aggregation of microglial cells in the brain stem and cerebral hemisphere. Azurophilic inclusion bodies were seen in the cytoplasm of some neurons. In electron micrographs, virus particles (60‐80 nm in diameter) were observed around the nucleus of neurons in the brain stem. No changes were observed in the juvenile and adult gerbils.
Physical and functional characterization of the cloned lysl + gene of Schizosaccharomyces pombe
Authors: Ford Richard A. , Ye Zhi‐Hai , Bhattacharjee J. K. 
Published: February 2007

AbstractThe α‐aminoadipate pathway for the biosynthesis of lysine is present in yeast and other higher fungi. The lys2 and lys5 mutants of Saccharomyces cerevisiae as well as the lys1– and lys7 –mutants of Schizosacharomyces pombe are blocked at the α‐aminoadipate reductase step of this pathway. The cloned lys1 + gene in the plasmid pLYS1 isolated from a S. pombe genomic library complemented lys1– mutant of S. pombe. The cloned LYS2 gene in the plasmid YEp620 and the LYS5 gene in the plasmid pSC5 of S. cerevisiae exhibited heterologous complementation of lys1– and lys7– mutants, respectively, of S. pombe. The homologous lys1 + transformed cells exhibited five fold higher α‐aminoadipate reductase activity while the heterologous lys1 + and lys7 + transformed cells exhibited much less activity than the the wild type cells. The DNA insert of the plasmid pLYS1 was determined to be 16.7 kb long and the lys1 + gene has been subcloned within a 9.1 kb Clal‐Clal DNA insert of the recombinant plasmids pLYS1B and pLYS1C. The restriction pattern for 12 enzymes of the 9.1 kb DNA insert, (Apal, Aval, BamHI, Clal, EcoRI, EcoRV, HindIII, Hpal, Pstl, Pvull, Sphl, and Xbal), exbibited no obvious similarity to that of the LYS2 gene of S. cerevisiae. A 1.7 kb EcoRI‐HindIII DNA fragment of pLYS1B and pLYS1C complemented the lys1‐131 mutation in an integrative transformation. Although the lys1 + gene of S.pombe is isofunctional to the LYS2 gene of S. cerevisiae, the restriction sites, and expression of these two genes exhibited considerable divergence.
Vanadium requirement for growth on N2 or nitrate as nitrogen source in a tungsten‐resistant mutant of the cyanobacterium Nostoc muscorum
Authors: Singh H. N. , Chakravarty D. , Rao K. Srinivasa , Singh A. K. 
Published: February 2007

AbstractA tungstate‐resistant mutant of Nostoc muscorum was isolated with severely defective molybdate transport activity. It did not show nitrogenase activity or nitrate reductase activity in the presence or absence of Mo, but expressed both activities in the presence of vanadyl sulphate. V‐dependent nitrate assimilation was accompanied by V‐dependent nitrate reductase mediated nitrate repression of heterocyst formation and nitrogenase in a way Mo‐nitrate reductase did in the parent.
Influence of the different amino acid substitutions in Escherichia coli thioredoxin on the growth of bacteriophages T7 and f1
Authors: Minárik Peter , Kollárová Marta , Brunovská Alena 
Published: February 2007

AbstractWe have constructed three mutants in the thioredoxin (trxA) gene changing its catalytic core between Cys‐32 and Cys‐35. Oligonucleotide‐directed mutagenesis was carried out to replace conservative Gly‐33 or Pro‐34 by leucine, lysine, glutamine, phenylalanine or tryptophane. The mutants were characterized using an in vivo assay based on the ability of cell (mutants in the chromosomal trxA gene) to support growth of T7 and filamentous f1 phages. The results indicate that the smaller group side‐chain in the position 33 and 34 of amino acid residues are indispensable for the growth of phages.
Co‐cultivation of tomato cell cultures with the pathogenPseudomonas syringaepv.tomato
Authors: Perner Birgit , Schmauder Hans‐Peter 
Published: February 2007

AbstractThe effect of a co‐cultivation with the pathogenPseudomonas syringaepv.tomato, strain 34, on plant cell cultures ofLycopersicon esculentumand its wild typeLycopersicon peruvianumwas investigated. The studied parameter were growth, vitality (TTC‐test, FDA‐test) cellular protein content, activities of polyphenol oxidase, peroxidase and PAL within the cells. Furthermore we estimated the rate of attached bacteria on the plant cell walls. The used tomato suspension cultures react in a quite different way to the pathogen.
Purification and characterization of nitrile hydratase of a mutant strain of Brevibacterium sp.
Authors: Moreau J. L. , Azza S. , Arnaud A. , Galzy P. 
Published: February 2007

AbstractThe nitrile hydratase from the mutant strain of Brevibacterium sp. ACV2 was purified and compared to that from the wild type R312. Its molecular weight was estimated at 80000. This enzyme is composed of 2 sub‐units with 26000 and 27500 molecular weights. The nitrile hydratase of the mutant strain is different from that of the wild type by its pHi, optimum activity pH, and its rates of hydrolysis of cyanovaleramide and cyanovaleric acid which were 30 and 15 folds greater.
Effect of phenol on the mycelial growth and fructification in some of basidiomycetous fungi
Authors: Upadhyay R. C. , Hofrichter M. 
Published: February 2007

AbstractCometabolic growth studies with phenol were undertaken to screen 32 strains of white and brown rot fungi. All the cultures studied grew well up to 4 mM of phenol on CZAPEKDOX agar except Agaricus bisporus (white button mushroom) and Pleurotus cystidiosus. Most of them could grow even up to 6 mM of phenol. Phenol induced a brown pigmentation of the culture medium. P. flabellatus and P. pulmonarius metabolized 67 and 64 mg/1 phenol in 10 days. Studies have indicated that phenol (0.1 to 1.0 mM) incorporated in malt‐extract agar has no inhibitory effect on fruitbody formation. Preliminary studies indicate that soaking of wheat straw with phenol solution up to 1600 mg/1 give better mycelial growth and fructification of P. cornucopiae, P. ostreatus Z‐15 and Calocybe indica than water soaked. Soaking of wheat straw in phenol inhibited the growth of common competitor weed fungi like Stachybotrys sp. and Coprinus sp.
Phosphorylated nutrient uptake by Treponema denticola and other potential periodontopathogens
Authors: Yotis William W. , Gopalsami Chellam , Corrigan Kevin , Hoerman Kirk , Keene Joseph J. 
Published: February 2007

AbstractNutrient uptake may contribute to the survival of certain potential periodontopathogens in the competitive environment of the gingival sulcus. This study was conducted to assess the uptake of commercially available, key radiolabelled phosphorylated compounds by Treponema denticola. There was a linear relationship in the uptake of ATP and G‐1‐P with cell concentrations of 0.1–2.5 mg of cell dry weight. This uptake reached a steady state within 15 min, and at temperatures of 25–37 °C the uptake ranged between 13–21%. At 50 °C, or above 50 °C the assay cells took up 0–1% of the assay nutrients. The maximum uptake of ATP was 47.5, 38 and 47.6 pmoles for serovars a, b and c. G‐1‐P yielded maximum uptake values of 306, 304, and 306 pmoles respectively. Significant uptake of ATP, or G‐1‐P occurred at pH 4.8 for serovars a, or c, while serovar b showed a broad pH range for the uptake of G‐1‐P. Stannous fluoride at a concentration of 0.17 mM enhanced the uptake of ATP while chlorhexidine digluconate inhibited the uptake of ATP. At concentrations usually employed (0.05–0.5 mM) the metabolic poisons 2,4‐dinitrophenol, sodium azide, sodium arsenite and the ATPase inhibitor N,N1‐dicyclohexylcarbodiimide did not alter significantly the uptake of ATP. The uptake of ATP, by Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum and T. denticola at pH 4.8 was 13.4, 1.5, 6.9, and 18–20.4%, respectively. At pH 6.5 the uptake for the microorganisms indicated above was 22, 1.3, 6.6 and 6.2%, respectively. G‐1‐P showed the same trend in its uptake by A. actinomycetemcomitans, P. gingivalis, F. nucleatum and T. denticola. This study provides for the first time specific examples of phosphorylated nutrient uptake by potential periodontopathogens, and that the uptake of phosphorylated nutrients can be suppressed by oral hygienic compounds.
Survey of mycoflora and mycotoxins in Egyptian soybean seeds
Authors: El‐Kady I. A. , Youssef M. S. 
Published: February 2007

AbstractAfter four months in commercial storage, 100 soybean samples from different places of Egyptian Governorates were assayed for filamentous fungal growth at two incubation temperatures (28 and 45 °C). 73 species and 8 varieties belonging to 32 genera were isolated by the dilution plate method. At 28 °C, the common species were Aspergillus flavus, A. fumigatus, A. niger and A. alutaceus, followed by A. terreus, Penicillium chrysogenum, P. citrinum, Mucor hiemalis, M. racemosus, Emericella nidulans, Rhizopus stolonifer, Nectria haematococca and Scopulariopsis brevicaulis. At 45 °C, A. fumigatus was the dominant species followed by Rhizomucor pusillus, Emericella nidulans and Neosartorya fischeri. Penicillium which was one of the most abundant genus at 28 °C, absent at 45 °C. The seeds were assayed for aflatoxin, ochratoxin A, sterigmatocystin, T‐2 and zearalenone by thin layer chromatographic analysis. Aflatoxin was detected in 35% of soybean seed samples (5–35 μg/kg). The other mycotoxins were not detected.
Toxicity of legume seeds to rhizobia: Selective marker for strain identification and selection of toxin‐free seeds
Authors: Jha Prakash K. , Nair Suresh , Babu C. R. 
Published: February 2007

AbstractSeeds of legume species Argyrolobium flaccidum, Desmodium elegans, D. tortuosum, Indigofera gangetica, Lespedeza stenocarpa and Sesbania sesban have been evaluated for the toxicity to rhizobia for the first time. Legume species differ in quantity and quality of released seed toxins to which the symbiotic bacteria respond differentially. Therefore, seed toxicity may be used as a selectable taxonomic marker for the strainal identification of rhizobia. Seed toxins are located in seed coat and are thermolabile to some extent. The seed genotypes, within the species, differ in toxicity and such polymorphism can be used in the selection of toxin‐free seeds. Seed surface‐disinfection procedures involving subsequent soaking and washing with water are the most useful methods for reducing the seed toxins. The seed toxins from I. gangetica inhibited the growth of its homologous strain but did not affect nodulation and symbiotic parameters. Various seed‐toxin‐producing legume species did not affect nodulation and symbiotic efficiency and effectiveness.
Cytochromes c‐dependent aerobic respiration of Paracoccus denitrificans
Authors: Kaplan Petr , Kučera Igor 
Published: February 2007

AbstractTerminal parts of the respiratory chain of Paracoccus denitrificans containing cytochromes c have been investigated through the use of NNN′Nprime;‐tetramethyl‐p‐phenylenediamine (TMPD) as an electron donor. The cells have been shown to possess two major membrane bound TMPD oxidases characterized by their different sensitivities to cyanide. The more sensitive one, identified as cytochrome aa3, appears to be produced under oxygen‐rich growth conditions, whereas a less sensitive and as yet uncharacterized enzyme accompanied with only moderate amounts of cytochrome aa3 functions when oxygen becomes limiting. The soluble periplasmic cytochrome cd1 does not contribute significantly to the total oxygen consumption rate, although its maximal catalytic capacity may be high. The fact thap the activity of alternative TMPD oxidase is not proportional to cytochrome o content is discussed in relation to possible occurrence of two distinct cytochrome o‐type terminal oxidases.
Influence of the insecticide Dimethoate on some metabolic activities of five zoosporic fungi
Authors: Khallil A. M. A. , Omar S. A. 
Published: February 2007

AbstractUsing sesame water culture and various doses of Dimethoate, no mycelial growth appeared in cultures at rate above 5 ppm. There was no appreciable effect of the low dose of the insecticide (2.5 ppm) when incorporated into water cultures on vegetative growth, asexual and sexual sporulation of all tested fungi compared with the control. Using liquid media, respiration, mycelial dry weight as well as protease, lipase, amylase and cellulase production were varied depending upon the doses and tested fungal species.
Differential response of two species of the cyanobacterium Anabaena to ultraviolet (UV‐C) irradiation
Authors: Patnaik J. , Swain N. , Adhikary S. P. 
Published: February 2007

AbstractUltraviolet sensitivity of two different species of Anabaena, Anabaena doliolum and Anabaena sp. was studied. These two species differ in their pigment composition; A. doliolum showed predominance of phycocyanin whereas Anabaena sp. showed predominance of phycoerythrin pigments. Survival of the two species were different after exposure to different doses of UV (λmot 254 nm) irradiation; Anabaena sp. was more resistant to higher UV dose than A. doliolum. In both species the UV induced damage was partially repaired by white fluorescent light. A. doliolum showed a lower rate of photorecovery than Anabaena sp., Higher UV dose (20 min) induced production of a non‐nitrogen fixing strain of A. doliolum and a pigment mutant lacking phycoerythrin of Anabaena sp.
Metabolism and physiological behaviour of Leuconostoc mesenteroides subsp. mesenteroides growing on raffinose
Authors: Prévost H. , Phalip V. , Huang D. Q. , Diviés C. 
Published: February 2007

AbstractThe α‐galactosidase activities of 11 strains of Leuconostoc mesenteroides subsp. mesenteroides grown on glucose, lactose or raffinose were determined. The inductive effects of lactose and raffinose differed depending on the strain. In four of the strains, α‐galactosidase activity of cells grown on lactose was higher than that of cells grown on raffinose, while the reverse was true for one other strain. The study of two strains exhibiting a different behaviour was extended to all raffinose‐component sugars: melibiose, sucrose, glucose, galactose and fructose. The apparent fermentation yields with raffinose‐component sugars complied with heterofermentation theory, except for sucrose, where there was a 40% deficit in fermentation products. Raffinose hydrolysis enzymes (α‐galactosidase and β‐fructosidase) underwent a catabolic repression by glucose. Growth on raffinose was considerably stimulated if the inoculum was first grown on melibiose or raffinose (induction of α‐galactosidase).
Isoenzyme profiles in Azotobacteraceae
Authors: Jana Subhas Chandra 
Published: February 2007

AbstractElectrophoretic comparison of isoenzymes of the members of Azotobacteraceae suggests that the genus Azotobacter consists of a heterogeneous group of bacteria. The new name Azomonotrichon macrocytogenes for Azomonas macrocytogenes is supported by the present investigation which was proposed earlier by numerical analysis study.
Iron supply of Pasteurella multocia and Pasteurella haemolotica
Authors: Reissbrodt R. , Erler W. , Winkelmann G. 
Published: February 2007

AbstractPasteurella multocida and Pasteurella haemolytica do not produce hydroxamate‐ or phenolate type siderophores. However, transport‐ and utilization systems could be detected for the well known siderophores ferrioxamine B, E, G, rhizoferrin and the intermediate 2,3‐dihydroxybenzoic acid by means of cross‐feeding tests in both Pasteurella species. Enterobactin and ferrichrome did not feed any of the Pasteurella strains tested. Additionally, α‐ketoacids and α‐hydroxyacids such as pyruvic acid, α‐hydroxyisovaleric acid and others acting as primary metabolites enabled growth of P. multocida and P. haemolytica under iron limitation.
Oomycetes and Chytridiomycetes (Mastigomycotina) from water bodies in Tübingen region (Germany)
Authors: El‐Hissy Farida T. 
Published: February 2007

AbstractTwenty‐five identified and 3 unidentified species in addition to one variety belonging to ten genera of aquatic fungi were recovered from 20 surface water samples collected from different aquatic sites in Tübingen region (Baden‐Württemberg, Germany) during July‐September 1992 using sesame seeds as baiting substances. Three genera were of high occurrence; Saprolegnia (8 species), Aqualinderella (one species) and Pythium (6 species) and two genera namely Achlya (2 species) and Dictyuchus (one species) were of moderate occurrence. Allomyces (3 species + one variety) and Aphanomyces (one species) were of low occurrence whereas Olpidiopsis, Phytophthora, Pythiopsis and Thraustotheca were of rare occurrence (one species each). Saprolegnia contributed the broadest spectrum of species (8 species). The richest water samples in Saprolegnia species (7 species) and the aquatic fungal species (15 species) was number one which collected from the river Neckar while this group of fungi disappeared completely in sample number (16). It seems that the most effective factor in the occurrence and distribution of this group of fungi during this study was the water temperature.