bluuebunny/crossref_metadata_2025_split huggingface dataset:
A genetic study of apramycin‐resistant mutants of Escherichia coli
Authors: Vasiljevic Branka , Fira Djordje , Topisirovic Ljubisa 
Published: February 2007

AbstractThe apramycin‐resistant mutants of E. coli were isolated spontaneously. Mutations, aprA and aprB, conferring resistance to apramycin were located at 72 min on the E. coli genetic map where most of ribosomal genes were mapped. One of the mutants, carrying the aprB mutation, has an altered translational fidelity expressed as severe restriction of amber suppressor activity in vivo. The chromosome location and altered translational fidelity indicate that the apramycin‐resistant phenotype could be a consequence of an alteration of the ribosomal structure.
Physiological and enzymatic characterization of cephalosporin acylases‐producing strain Pseudomonas L24
Authors: Zhang Qui‐Jiu , Xu Wan‐Xue 
Published: February 2007

AbstractCephalosporin acylases‐producing strain L24 was isolated from soil sample. The morphological, physiological and enzymatic properties were studied. The results suggest that this strain belongs to the genus Pseudomonas and is designated as Pseudomonas strain L24. The enzymes produced by the cells can convert both cephalosporin C and 7 ‐Gl‐(4‐carboxylbutanamido) into 7‐amino cephalosporanic acid.
Characterization of the Rhodococcus sp. BPG‐8 resorcinol hydroxylase
Authors: Armstrong S. M. , Patel T. R. 
Published: February 2007

AbstractA thermo‐unstable hydroxylase was isolated from a Rhodococcus sp. BPG‐8. Activity for the partially purified hydroxylase was enhanced and stabilized in the presence of FAD and catalase. The Vmax values for the oxidation of NADH was 0.28 μmoles · min−1 · mg−1 protein and Km value was 8.3 μM in the presence of these compounds, while in their absence the Vmax value was reduced to 0.09 μmoles · min−1 · mg−1 protein while the Km value changed to 16.1 μM. Resorcinol hydroxylase activity was optimal at pH 7.0, and 25° C. The optimal substrate concentrations were 68 μM and 125 μM in the presence and absence of FAD/catalase, respectively. Chloride ion, and metal ions inhibited the resorcinol hydroxylase activity. The resorcinol hydroxylase utilized various other substrates, and did not influence the hydroxylase activity in the presence of resorcinol.
Fungi from water, soil and air polluted by the industrial effluents of Manquabad superphosphate factory (Assiut, Egypt)
Authors: Khallil A. M. , Abdel‐Sater M. A. 
Published: February 2007

AbstractOne hundred and one species in addition to three varieties appertaining to 53 genera of zoosporic (25 species and 15 genera) and terrestrial (76 species + 3 varieties and 38 genera) fungi were isolated during this investigation. The water and submerged mud directly exposed to industrial effluents were the poorest in terrestrial fungi whereas zoosporic fungi were completely missed. These samples were highly acidic, low content of oxygen and relatively high contents of total soluble salts, phosphate, sulphate, calcium and magnesium. Dictyuchus sterilis and Aphanomyces laevis were the most common zoosporic species using baiting technique whereas Aspergillus fumigatus, A. niger, A. flavus, Alternaria alternata, Gibberella fujikuroi and Stachybotrys chartarum were the most prevalent terrestrial fungal species using glucose‐ and cellulose‐CZAPEK's agar media. Tripospermum sp. (aquatic hyphomycetes) was isolated from the phyllosphere of Myriophyllum spicatum and is new record to Egypt. There are some variations concerning the fungal diversity frequencies and populations with regard to the test sources and media used.
Toxigenic fungi and mycotoxin content in poultry feedstuff ingredients
Authors: Mahmoud A.‐L. E. 
Published: February 2007

AbstractFifty isolates of Aspergillus flavus as well as 25 isolates of each of A. fumigatus, A. ochraceus, A. terreus and Fusarium spp. isolated from poultry feeds were screened for toxin production. Of these isolates, 20% have been detected to exhibited toxigenic activity.The mycotoxin content was determined in samples of grind maize, cotton‐seed cake, fish meal, wheat bran and soybean meal. 80% of maize samples were highly contaminated with aflatoxins (480 μ/kg) and zearalenone (40 μ/kg). Aflatoxins B1 and B2 were found in 50 and 30% of cotton‐seed cake and fish meal, respectively. With wheat bran, 40% of the samples contained aflatoxin B1 and zearalenone. Soybean meal appeared to be a poor substrate for mycotoxin formation.
Nutritional factors controlling exocellular proteinase production in a soil‐isolated Xanthomonas maltophilia strain
Authors: Singer Elisabeth , Debette Jaqueline 
Published: February 2007

AbstractThe exoproteinase of Xanthomonas maltophilia C17 is secreted in the absence of any inducer. When a carbohydrate source (glucose, mannose, cellobiose or maltose) is added to casein‐containing cultures, the bacterial growth is increased to the same extent regardless of the nature of the carbohydrate added. Conversely, proteinase production is enhanced in the presence of cellobiose or glucose, but is repressed in the presence of mannose or maltose compared to the control culture grown without sugar. This repression does not result in an accumulation of proteinase within the cell and is not due to the failure of some secretion process since the enzyme is synthesized de novo. Maltose and mannose are known to be easily metabolizable substrates for X. maltophilia. They seem to be involved in a kind of catabolite repression that cannot be relieved by the addition of cyclic AMP or dibutyryl cyclic AMP and to exert their effect at the transcriptional level.
Involvement of two genes of superinfecting phage Kappa in curing and induction of prophage Psi in Serratia marcescens HY
Authors: Steiger H. 
Published: February 2007

AbstractProphage Ψ carried along with prophage y by Serratia marcescens HY is subject of moderate curing at heteroimmune superinfection of cells from stationary phase with phage χ. Curing becomes considerably more frequent when the bacteria are non‐iysogenic for y. Both Ψ, y‐double‐lysogenic and Ψ‐single‐lysogenic cells with a mutation in the ink gene are very efficiently cured of Ψ if infected by χtay, although this mutant was characterized as being deficient in transactivation of certain genes in prophage y. On the other hand to get efficiently cured after χ wild‐type infection these cells too must be devoid of a y prophage. Thus a y function turned on by tay+ seems to counteract the elimination of Ψ. However, interestingly enough Ψ curing is boosted by a further y function under special circumstances. Efficient curing depends on an intact χtap gene, a gene reported to cause transactivation of certain Ψ genes. Curing at χtay infection is specifically accompanied by induction of the Ψ prophage in a part of the infected cells. However, there is no such induction at χ wild‐type infection, either in the absence or presence of a y prophage. An explanation of these findings is suggested which includes an antirepressive effect exerted on Ψ and a hypothetical interaction between the products of genes tap and tay.
Microbial transformation of isoprenoid systems by means of Zoophthora (Erynia) ovispora (NOWAKOWSKI) BATKO
Authors: Urbańczyk Jerzy M. , Sołoducho Jadwiga , Zabźa Andrzej , Sodano Guido , Grassi Alfonso 
Published: February 2007

AbstractEpoxidation of double bond was the main reaction performed by Zoophthora (Erynia) ovispora on methyl and ethyl α‐campholenyl ketones 1 and 6. Apart from epoxides 2, 3, 7, and 8, some other products were isolated, with additional oxygen function in α‐position to the double bond (9 and 10). The presence of the BAEYER‐VILLIGER reaction product (4) and diketone 11 is also postulated.
Fermenter cultivation of intestinal spirochaetes
Authors: Borrmann Erika , Blaha Thomas , Günther Horst 
Published: February 2007

AbstractWe cultivated 6 strains of intestinal spirochaetes in a laboratory fermenter under constant conditions (medium, physical‐chemical parameters) in a permanent gas flow. It has been possible to demonstrate that the application of the fermenter technique for the cultivation of spirochaetes is a suitable method which can be easily standardized.
Taxonomy of lactic acid bacteria from spoiled, vacuum packaged vienna sausages by total soluble protein profiles
Authors: Dykes Gary , Holy Alexander Von 
Published: February 2007

AbstractTo resolve the taxonomic status of sixty‐one lactic acid bacteria isolated from spoiled, vacuum packaged vienna sausages, a computer assisted analysis of total soluble protein profiles was undertaken. Sixty‐two % of the strains in the study were recovered in fourteen clusters at the 72% similarity level, indicating high degree of heterogeneity among the strains examined. Two clusters representing Leuconostoc species were the largest and most homogeneous, containing twenty strains between them. One cluster contained both typical Lactobacillus saké and Lactobacillius curvatus strains, indicating the inability of protein profiles to consistently differentiate between all strains of these two species. The presence of an independent Lactobacillus curvatus grouping and the clustering of some atypical strains with Lactobacillus saké isolates, however, indicated that the atypical strains may be closely related to Lactobacillus saké.
Occurrence and characterization of lectins in actinomycetes
Authors: Singh Jatinder , Ahluwalia Jasleena , Kamboj Sukhdev Singh , Singh Surinder 
Published: February 2007

Abstract25 species of actinomycetes were tested for the occurrence of lectins. Using a battery of normal and desialized erythrocytes, each species was screened for 3 types of lectin activity i.e. surface bound, extracellular and intracellular. As many as 13 species showed one or more types of activity; some of them were characterized with regard to their biological action spectrum and sugar specificity.
Utilization of aromatic compounds by the Penicillium strain Bi 7/2
Authors: Hofrichter Martin , Scheibner Katrin 
Published: February 2007

AbstractThe Penicillium strain Bi 7/2 utilized phenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyhydroquinone, phloroglucinol, m‐ and p‐cresol, orcinol, 4‐methylcatechol. 4‐methoxy‐phenol, 4‐aminophenol, benzyl alcohol, benzoic acid, 2‐, 3‐ and 4‐hydroxybenzoic acid, anthranilic acid, protocatechuic acid and gallic acid as sole sources of carbon and energy. The central metabolites catechol, protocatechuic acid and hydroxyquinone could be determined by HPLC with diode‐array detection. Pathways for the degradation of aromatic substances were proposed.
Purification and properties of NAD+‐dependent formate dehydrogenase produced by Agrobacterium sp.
Authors: Iida Mitsugi , Ohtsuki Shin'Ichi , Mineki Shigeru 
Published: February 2007

AbstractFormate: NAD+ oxidoreductase (EC 1.2.1.2) with high affinity to formate was purified from a facultative formate‐utilizing Agrobacterium sp. MIL 1052. From a cell extract, the enzyme was purified to homogeneity by ammonium sulfate fractionation, DEAE‐Sephadex A‐50 column chromatography, Sephadex G‐200 column chromatography, and hydroxyapatite column chromatography. The enzyme amounted to 9.1% of intracellular soluble proteins in strain MIL 1052. The subunit Mr, estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, was 50 kDa. The Mr of the native enzyme was estimated to be 112 kDa by gel filtration, suggesting a dimeric structure. The enzyme had an isoelectric point of 7.0. The pH and temperature optima were 5.5–7.0 and 30–45 °C, respectively. The enzyme was stable at pH 6.0–7.5 and at up to 35 C. The apparent Km values for formate and NAD+ were calculated to be 0.13 mM and 0.17 mM, respectively.
In vitro coronatine production by several Pseudomonas syringae pv. glycinea isolates
Authors: Nüske Jörg , Bublitz Friedemann 
Published: February 2007

AbstractCoronatine production by several Pseudomonas syringae pv. glycinea strains has been studied in batch culture. A reversed‐phase high‐performance liquid chromatographic procedure was developed for rapid quantitation of coronatine in culture fluids. Coronatine and coronafacic acid have been recognized from their mass spectra. Three of the strains investigated showed no detectable amounts of coronatine. Four of the examined high producing wild type strains produced much more coronatine as have been already reported for P. syringae pv. glycinea strains, none of them showed detectable coronafacic acid production. Coronatine production is strictly growth associated. Two strains showed a break down of coronatine already at the beginning of the stationary growth phase.
Metabolism of aniline and 3‐chloroaniline in Pseudomonas acidovorans CA28: Evidence of isofunctional muconate cycloisomerases
Authors: Hinteregger Christel , Ferschl Andreas , Loidl Michael , Streichsbier Franz 
Published: February 2007

AbstractTwo distinct muconate cycloisomerases are involved in the degradation of aniline and 3‐chloroaniline (3‐CA) proceeding via the ortho‐cleavage pathways in Pseudomonas acidovorans CA28. After partial purification of these two enzymes kinetic investigations resulted in a clear differentiation of aniline‐derived muconate cycloisomerase (MC) and 3‐CA‐derived chloromuconate cycloisomerase (CMC). A further result of this study revealed the simultaneous coexistence of MC and CMC in strain CA28 when grown on a mixture of aniline and 3‐CA.
Investigations of the oxygen supply in Ca‐alginate beads and microcapsules loaded with Penicillium raistrickii using a microelectrode
Authors: Irrgang S. , Baumgärtl H. , Schlosser D. , Zimelka W. , Schmauder H.‐P. 
Published: February 2007

AbstractThe oxygen supply of free, Ca‐alginate entrapped and microencapsulated mycelia of Penicillium raistrickii i 477 capable of 15α‐hydroxylation of 13‐ethyl‐gon‐4‐en‐3,17‐dione was investigated. Using an oxygen microelectrode distinct gradients of oxygen within the Ca‐alginate beads as well as the microcapsules were detected. Slope and width of the gradients were investigated in dependence on the kind of immobilization, the culture age and the cell density on or in the carrier as well as the different forms of the oxygen supply in the medium. So it could be shown that large parts of immobilizates, approximately 96% of the diameter of both types, were oxygen‐free. In comparison with free mycelia, the lower oxygen supply of the immobilized mycelia led to a metabolic shift to fermentative catabolism.
Growth kinetics of Rhodotorula rubra on different substrates
Authors: Hari Ravinder P. K. , Patel Thakor , Martin Antonio M. 
Published: February 2007

AbstractThe growth of a red‐pigmented yeast, isolated from yogurt and identified as Rhodotorula rubra, was studied on various industrial and agricultural by‐products. Peat hydrolysate when supplemented with peptone and yeast extract supported a satisfactory growth of the yeast. Ammonium hydroxide and ammonium sulfate were the best inorganic nitrogen sources. A yield of 11.8 g/1 was obtained on molasses and wort used in a concentration of 10 and 40% (v/v), respectively. Molasses were pre‐treated to be effective. The best yield of 14 g/1, however, was obtained on a richer medium composed of molasses, peptone and yeast extract. The pH profiles were also studied and growth was found within a broad pH zone of 3–10.
Rapid identification and differentiation of yeasts by DNA and PCR fingerprinting
Authors: Lieckfeldt Elke , Meyer Wieland , Börner Thomas 
Published: February 2007

AbstractWe have used the techniques of DNA fingerprinting and polymerase chain reaction (PCR) with probes specific for hypervariable repetitive DNA sequences (mini‐ and microsatellite DNAs) to analyze 36 yeast strains belonging to 10 species and 2 genera. Using (GTG)5, (GACA)4, phage M13 DNA and the M13 sequence GAGGGTGGCGGTTCT as probes and primers, respectively, we obtained DNA polymorphisms which allowed us to discriminate 23 biotechnologically important strains of the yeast Saccaromyces cerevisiae and to distinguish them from strains of S. pastorianus, S. bayanus and S. willianus.Our results demonstrate that both DNA and PCR fingerprinting are suitable tools for an easy, fast and reliable molecular typing of yeasts. The DNA fingerprinting method seems to be more sensitive than PCR fingerprinting with respect to the individualization of strains. Nevertheless, using the PCR fingerprinting technique we were able to unambigously dicriminate between yeast genotypes of different species. Therefore, PCR fingerprinting might become a useful tool in the classification of yeasts on the basis of phylogenetic relatedness.
Polysaccharide production in Pseudomonas cepacia
Authors: Allison David G. , Goldsbrough Melanie J. 
Published: February 2007

AbstractThe effects of glucose, osmolarity, temperature and mode of growth on exopolysaccharide production in Pseudomonas cepacia was studied in batch culture using a chemically defined growth medium. Polymer production was maximal under conditions of a 2% (w v) glucose supplement, 0.4 m NaCl and an incubation temperature of 35 °C. In addition, polysaccharide composition and molecular weight varied with mode of growth. On agar culture there was a decrease in pyruvate and rhamnose content yet an increase in the amount of acetate compared to the polymer isolated from broth culture equivalents. The clincial implications of these results are discussed in relation to the potential pathogenicity of P. cepacia in cystic fibrosis patients.
Influence of the age and growth conditions on the mycelial chitin content of Lentinus edodes
Authors: Lena Gabriella Di , D'Annibale Alessandro , Sermanni Giovanni Giovannozzi 
Published: February 2007

AbstractThe chitin content of Lentinus edodes mycelium was studied in liquid cultures in order to evaluate the suitability of chitin as a fungal growth parameter in solid state cultures. The influence of ageing, medium composition and growth conditions on the glucosamine content of L. edodes were observed. Low glucosamine values were found in correspondence with early growth while, by the end of the exponential phase, the mycelial glucosamine level reached a maximum constant value. The supplementation of the liquid synthetic medium with corn straw (Zea mais) extract, while inducing extracellular phenoloxidase activities, did not influence significantly the glucosamine content of L. edodes mycelium. Mycelium grown under stationary conditions showed a lower content of glucosamine when compared with mycelium grown under shaking conditions.
Extraction and analysis of indole derivatives from fungal biomass
Authors: Gartz Jochen 
Published: February 2007

AbstractThe occurrence and extraction of indole derivatives in six species from four genera of higher fungi were investigated. By using pure methanol for extraction of the mushrooms analysis revealed the highest concentrations of psilocybin and baeocystin. The psilocin content of the species was higher by using aqueous solutions of alcohols than with methanol alone but was an artificial phenomenon caused by enzymatic destruction of psilocybin. The extraction with dilute acetic acid yielded better results than with the water containing alcohols.The simple one‐step procedure with methanol for the quantitative extraction is still the safest method to obtain the genuine alkaloids from fungal biomass.
Instability of plasmid encoding for β‐galactosidase in Leuconostoc mesenteroides subsp. mesenteroides
Authors: Huang D. Q. , Prévost H. , Kihal M. , Diviès C. 
Published: February 2007

AbstractThe appearance of Lac− variants of Leuconostoc mesenteroides subsp. mesenteroides 19D was studied in different growth conditions, at 30 and 37 °C, in milk and buffered or unbuffered MRS medium. Growth in milk resulted in greater stability of the lactose phenotype. The highest frequency of Lac− variants (40%) appeared in the culture in which mortality was the highest (unbuffered MRS, 37 °C, 96 h). The growth kinetics and fermentation balances of Lac− variants and of the parental strain were identical. No phospho‐β‐galactosidase activity could be detected. The activity of β‐galactosidase was high after growth in lactose‐containing medium and was low in glucose medium. Glucose totally repressed galactokinase activity. Enzymatic analyses of Lac− variants showed that the Lac− character was associated with the total absence of β‐galactosidase activity, in turn correlated with the loss of the 47.3 kb plasmid. An oligonucleotide probe corresponding to a homologous sequence of Leuconostoc lactis β‐galactosidase enabled the β‐galactosidase gene to be localized on this plasmid.
Characterization of temperature‐induced changes in the photosynthetic properties of Anacystis nidulans grown at elevated temperature: A differential response to heat shock
Authors: Singh D. P. , Verma Kavita 
Published: February 2007

AbstractPhotosynthetic properties of high temperature (38 °C) grown (HTG)1 and low temperature (25 °C) grown (LTG) cells of Anacystis were examined. The results revealed several characteristic changes in the HTG cells which included light absorption property of the pigments, DCMU binding affinity of the photosynthetic apparatus and photosynthetic yield. There was a time course dependent heat shock (47 ± 1 °C) induced inhibition of the O2 evolution in both the types of cells. However, the response of the HTG cells was sluggish as compared to the LTG cells. Unlike the LTG cells, the heat shock treatment (47 ± 1 °C, 5 min) of the HTG cells did not result into a change in the pigment absorption spectra. The rise kinetics of fluorescence induction curve of chlorophyll a in the presence of DCMU and DCMU + NH2OH suggested for heat‐induced damage to the oxidizing side of photosystem II in both the HTG and LTG cells. Further, results on the Hill activity in the heat shocked HTG cells showed that the exogenous electron donors DPC and NH2OH not only retrieved the heat shock induced inactivation of the Hill activity, but stimulated the rate of activity. On the other hand, the rate of Hill activity in the heat shocked LTG cells was restored by only NH2OH an electron donor to PS II reaction centre, while DPC‐an electron donor to water oxidation complex was ineffective against the heat shock induced inactivation of the electron transport. These results, together, suggested for the presence of less number of heat susceptible sites in the HTG cells than that in the LTG cells, which might be accounting for the high degree of thermostability to the former type of cells.
Effect of immune serum, an antibiotic, and a corticosteroid used alone or in combination on experimental leptospirosis in Mongolian gerbils (Meriones unguiculatus)
Authors: Yukawa M. , Kamata H. , Ohba S. , Kadoi K. , Mochizuki K. 
Published: February 2007

AbstractThe results suggest that the combined used of immune serum and corticosteroid (pledonizoron: PZ) inhibits the effects of serum and the marked effects of antibiotic (procaine penicillin‐G: PC‐G) on leptospirosis. PZ had no effects and rather shortened the survival period. PZ did not affect the effects of PC‐G when used in combination.These results suggest that treatment of leptospirosis with corticosteroids requires special caution.
Petite mutants of sophorolipid‐producing Candida yeasts
Authors: Hommel Rolf K. , Baum Annette , Kleber Hans‐Peter 
Published: February 2007

AbstractTreatment of both Candida apicola IMET 43747 and Candida bombicola ATCC 22214 with N‐methyl‐N′‐nitro‐N‐nitroso guanidine resulted in formation of auxotrophic mutants and cytochrome oxidase negative mutants. The deficiency of intact cytochrome oxidase did not affect the ability to produce sophorose lipid. This indicates that intact mitochondrial energy supplying system is not necessary for the production of the extracellular sophorose lipids by both Candida yeasts.