bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social behaviour of microbial populations
Authors: Oleskin Alexander V. 
Published: February 2007

AbstractThis paper covers the recent data on the biosocial interactions of microbial cells in populations. These interactions are considered in terms of general ethological and sociobiological concepts such as agonistic behaviour, affiliation, cooperation and coordination. Microbial social behaviour exemplified by the interactions among individuals in the supraorganismic structures of myxobacteria, Proteus mirabilis, Escherichia coli, myxomycetes and fungi is compared (i) to the cell behaviour involved in the development of animal embryos and immune responses of multicellular organisms and (ii) to the collective behaviour of higher animals in groups or communities. Special attention is given to the biotechnological implications of microbial sociality.
A periplasmic insulin‐cleaving proteinase (ICP) from Acinetobacter calcoaceticus sharing properties with protease III from Escherichia coli and IDE from eucaryotes
Authors: Fricke Beate , Betz Richard , Friebe Sieglinde 
Published: February 2007

AbstractA periplasmic insulin‐cleaving proteinase (ICP)1), purified to its electrophoretic homogeneity in the SDS‐PAGE from the Gram‐negative bacterium Acinetobacter calcoaceticus, was examined and compared in its properties with the protease III (protease Pi, pitrilysin, EC 3.4.99.44) of Escherichia coli and the insulin‐destroying proteinase (IDE, insulinase, EC 3.4.99.45) from eucaryotes. The enzyme was proven to be a metalloprotease like protease III and IDE, as was shown by the inhibitory effects exerted by EDTA and o‐phenanthroline. Furthermore, dialysis against EDTA and o‐phenanthroline led to a complete loss of activity, which could be restored by addition of Co2+, and, to a lesser extent, but at a lower metal ion concentration by Zn2+Similar to protease III and IDE, ICP prefers the cleavage of small polypeptides (insulin, insulin B‐chain, glucagon) to the cleavage of proteins (casein, human serum albumin, globin) and was inactive against synthetic amino acid derivates (esters, p‐nitranilides, and furoylacroleyl substrates) of subtilisin, thermolysin, trypsin, and chymotrypsinThe peptide‐bond‐specificity of the ICP in the cleavage of the oxidized insulin B‐chain was investigated and the results were compared to the specificity of protease III of E. coli, IDE, protease‐24,11, and thermolysin. Cleavage sites in the oxidized insulin B‐chain generated by ICP are Asn3‐Gln4, His10‐Leu11, Ala14‐Leu15, Leu17‐Vall8, Gly23‐Phe24, Phe24‐Phe25, and Phe25‐Tyr26. Principally, ICP cleaves between hydrophobic amino acids and amides. The ICP shares one of the only two cleavage sites with the protease III and four sites with the IDE.
Growth and pigmentation in Rhodotorula rubra and Phaffia rhodozyma
Authors: Sangha Ravinder P. K. , Patel Thakor , Martin Antonio M. 
Published: February 2007

AbstractThe kinetics of growth and pigment formation of R. rubra TP 1 and P. rhodozyma were studied. The pigment in both the organisms was detected in the exponential phase. The treatment with funcelase enzyme was found to be ineffective for the extraction of pigment from R. rubra cells. In the case of Phaffia, the pigment extractable from enzyme treated cells was twice the amount that of mechanically ruptured cells. The mechanically ruptured R. rubra cells yielded three and a half times more pigment than P. rhodozyma ruptured by a similar method.
Neutral lipids of fungus Zoophthora
Authors: Zabża Andrzej , Karaszewski Radoslaw , Szafranek Beata , Synak Elżbieta , Szafranek Janusz 
Published: February 2007

AbstractCultivation of Zoophthora (Erynia) neoaphidis, in comparison with other species of Zoophthora genus, requires more complex nitrogen source. The best mycelium growth was obtained when 8 day old mycelium was used as an inoculum for liquid culture. On the basis of Gas Chromatography/Mass Spectrometry (GC/MS) methods, the structures of the neutral lipids produced by this fungus species, were determined. Decanoic acid was the most characteristic component (over 45%). The level of hexadecanoic and octadecanoic acid was relatively lower, although their contribution as „bonded”︁ acid in diacylglyceride (DG) and triacylglyceride (TG) fractions, was significant. Contrary to Zoophthora (Erynia) ovispora, the presence of campesterol and/or dihydrobrassicosterol was proved.
Conditions for isolation of regenerating protoplasts from Pleurotus sajorcaju
Authors: Das N. , Mukherjee M. 
Published: February 2007

AbstractLow rate of protoplast regeneration of Pleurotus spp. is one of the limiting factor for strain improvement through protoplast technology. A method for overcoming this barrier and isolation of higher frequency of regenerating protoplasts both from mycelium and sporophore capable of producing fruit bodies is reported in this communication.
Biosynthesis of poly‐3‐hydroxybutyric acid by the facultatively methanol‐assimilating bacterium Mycoplana rubra B346 and recombinant strains
Authors: Foóllner Christina G. , Müuller Susi , Steinbüchel Alexander , Babel Wolfgang 
Published: February 2007

AbstractMycoplana rubra B346 is a pink‐pigmented facultatively methylotrophic bacterium which is capable of synthesizing and accumulating small amounts of poly‐3‐hydroxybutyric acid (PHB) if a carbon source (e.g. methanol) is provided in excess and if an essential nutrient (e.g. nitrogen or phoshorus, respectively) is limiting growth. Upon transfer of the PHA‐biosynthesis genes of Alcaligenes eutrophus H16 or Chromatium vinosum D or of the isolated PHA‐synthase structural gene of Methylobacterium extorquens into M. rubra B346, the content of PHB increased from 9.6 up to 25% of the cell dry matter. M. rubra and some recombinant strains were characterized physiologically and morphologically, and the size of the cells and the PHB content were compared by flow cytometry.
Constitutive nitrate‐ and nitrite reductase activities of Rhizobium in relation to denitrification
Authors: Halder A. K. , Chakrabartty P. K. 
Published: February 2007

AbstractNitrate reductase (NR) activity of R. meliloti SU 47 grown in yeast extract mannitol (YM) medium not containing any nitrate was highest during early stationary phase of growth. The strain did not express nitrite reductase (NiR) activity under this condition. In this medium stationary phase cells of some strains of rhizobia expressed nitrite reductase activity and produced gas from nitrate or nitrite in Durham tubes under anaerobic condition in 72 hrs. The strain SU 47, although, did not produce any gas in 72 hrs, did so and expressed NiR activity when grown for 8 days under anaerobic condition. The data indicated a positive correlation between gas production and NiR activity.
Immunochemical features of a macromolecule of Treponema denticola
Authors: Yotis William W. , Macaluso Fred , Gopalsami Chellam 
Published: February 2007

AbstractIn this study the extraction and the immunochemical features of a lipopolysaccharide‐like (LPSL) macromolecule of T. denticola strains 35405, 35404, 33521 and 11 were investigated. The yield of LPSL molecule ranged between 0.5‐0.9% of the cell dry weight, it possessed Limulus amebocyte lysate clotting activity, and it contained glucosamine, phosphate, heptose, glucose, small amounts of KDO, myristic and beta hydroxy myristic acid. Sera obtained from healthy individuals (ADA type I) periodontitis, from 3‐8 month old infants, or the mouse monoclonal antibody, diluted 1:2, against T. pallidum did not react with the LPSL antigens of T. denticola strains 35405, 35404, 33521, and 11. Sera from patients with ADA type III‐IV periodontitis were reactive with two 8‐14 kDa bands even at serum dilutions of 1:2000. Sera from patients with ADA type II periodontitis showed good antibody response to the 8‐14 kDa band at a dilution of 1:50, but were weekly reactive, or nonreactive at serum dilutions of 1:200. This study indicates that extraction of a lipopolysaccharide‐like macromolecule is feasible from the assay spirochetes, and this macromolecule may be used as an antigen for the diagnosis of ADA types II‐IV periodontitis.
Isolation and characterization of nitrogen‐fixing moderate halophilic bacteria from saline soils of Egypt
Authors: Zahran H. H. , Ahmad M. S. , Afkar E. A. 
Published: February 2007

AbstractTwenty out of 400 isolates of bacteria mainly from salt marshes and saline soils of Egypt were successfully grown on mannitol N‐free medium. The nitrogen‐fixing activity was then demonstrated for the twenty isolates in modified Stanier'S medium using the acetylene reduction assay. All of them possessed appreciable nitrogenase activity (acetylene reduction) under non‐saline conditions; however, at 5% NaCl only 60% of the isolates exhibited a high rate of this activity and 25% were completely negative under these conditions. The bacterial isolates grew well in Stanier'S medium; nevertheless, growth of the majority of isolates was reduced by about 30‐80% in the same medium containing 5% NaCl. Cellulolytic activity was detected in 60% of the twenty strains, amylolytic in 45%, and pectinolytic in 10% of the isolates. The bacterial isolates showed also enzymatic activity under saline conditions (5% NaCl). The preliminary identification indicated that six isolates were Gram positive spore‐forming bacteria of the genus Bacillus, the others were Gram negative rods which remain to be identified.
Bioconversion of methyl ricinoleate to 4‐hydroxy‐decanoic acid and to γ‐decalactone by yeasts of the genus Candida
Authors: Endrizzi Anne , Belin Jean‐Marc 
Published: February 2007

AbstractThe capacity of several strains of yeasts to do the bioconversion of the methyl ricinoleate into γ‐decalactone, was studied in a medium containing this methylic ester of fatty acid as sole carbon source. Amongst the strains which are able to do this bioconversion, two types of behaviour are observed: some of the strains produce γ‐decalactone during all the incubation in bioconversion medium while others produce this aroma compound very quickly and then consume it fast too. The tested strains produce at the same time γ‐decalactone and the corresponding acid form (4‐hydroxy‐decanoic acid), and this, in variable proportions.
Studies on bacteriocinogenic Lactobacillus isolates from selected Nigerian fermented foods
Authors: Olasupo N. A. , Olukoya D. K. , Odunfa S. A. 
Published: February 2007

AbstractTen bacteriocin‐producing (bacteriocinogenic) Lactobacillus isolates obtained from three Nigerian fermented foods namely: kenkey, ogi and wara were tested against the following indicator organisms: Lactobacillus plantarum and food borne pathogens comprising enterotoxigenic Escherichia coli, enterohaemorrhagic Escherichia coli, Serratia, Pseudomonas, Vibrio cholerae, Aeromonas sobria, Aeromonas cavice, Salmonella typhimurium, Plesiomonas shigelloides and Staphylococcus aureus. All the bacteriocinogenic Lactobacillus were found to inhibit L plantarum while some inhibited some of the food borne pathogens listed aboveThe antimicrobial activities of bacteriocins from L plantarum KKY12 and L casei OGM12 were caused by proteins detectable in the culture liquids. They are designated Plantacin N and Caseicin A and they have narrow antimicrobial spectra. Plantacin N from L. plantarum KKY12 was active against L plantarum. Pseudomonas. Aeromonas sobria and Aeromonas cavice whereas Caseicin A from L casei OGM12 inhibited L. plantarum, enterotoxigenic Escherichia coli and Vibrio choleraeCaseicin A is stable at 121 C/15 mins, and both are inactivated by proteolytic enzymes. The bacteriocinogenic properties of the local isolates of Lactobacillus can help to reduce hygienic risk and the spoilage of fermented foods.
Phenol degradation by Acinetobacter calcoaceticus NCIB 8250
Authors: Paller Gerhard , Hommel Rolf K. , Kleber Hans‐Peter 
Published: February 2007

AbstractAcinetobacter calcoaceticus NCIB 8250 utilizes phenol as sole source of carbon and energy via an ortho‐cleavage pathway. The presence of ethanol in mixed substrate cultivations repressed the utilization of phenol. In fed batch cultivation the phenol tolerance was increased at least 2‐fold. Maximum degradation rates of 150 Mg phenol/(l h) and 280 mg phenol/(g h). respectively were observed. Phenol hydroxylase is induced by its substrate and in parallel the catechol‐l,2‐dioxygenase is detectable. The presence of active phenol hydroxylase is strongly connected with the phenol degradation. Using a spectrophotometric enzyme assay the partially purified phenol hydroxylase was characterized with respect to kinetic parameters. The apparent Km values for phenol, FAD and NADPH were estimated to be 147 μm, 35 μm and 416 UM, respectively. Both FAD and NADPH were essential for maximum activity of the cytoplasmically localized enzyme. No substrate inhibition of phenol hydroxylase by phenol was observed up to 0.8 mM. The pH and temperature optima were pH 7.8 and 33°C, respectively. The partially purified enzyme showed a broad substrate specificity. It hydroxylated the three isomeric cresols, chlorophenols and methylated chlorophenols. Pyrogallol, 3,4‐dihydroxy‐L‐phenylalanine and resorcinol were oxygenated with higher rates than phenol. With the exception of phenol all other enzyme substrates tested did not serve as growth substrates.
The acidic ribosomal proteins of different yeast species. Phosphorylation by ribosome‐associated protein kinases
Authors: Cytryńska Malgorzata , Wojda Iwona , Jakubowicz Teresa 
Published: February 2007

AbstractTwo major ribosomal proteins of Mr 13 kDa and 38 kDa were identified as phosphorylation substrates for ribosome‐bound protein kinases from different yeast species. The phosphorylation level was much higher in ribosomes from the cells collected at the exponential growth phase, than in those from the stationary phase. Isoelectrofocusing of the protein band of 13 kDa and subsequent silver staining allowed to identify from four in the case of Pichia stipitis up to ten in Saccharomyces cerevisiae, Saccharomycodes Ludwigii, Torulopsis utilis and Kloeckera apiculata individual peptides. In the most of the yeast species studied five phosphorylated peptides were observed. However, only one or two such phosphopeptides were detected in Pichia stipitis and Trichosporon cutaneum ribosomes, respectively. The same phosphoprotein forms were identified in the in vivo 32P‐labelling experiments.
Optimal conditions for production of dextransucrase from Leuconostoc mesenteroides NRLL B‐512F and its properties
Authors: Goyal Arun , Nigam Manisha , Katiyar Sarvaguy S. 
Published: February 2007

AbstractDextransucrase production from Leuconostoc mesenteroides NRRL B‐512F was carried out in batch cultures under different conditions in static culture conditions. Small changes in the temperature had a significant effect on the enzyme production. A temperature of 23°C gave the maximum yield of the enzyme. An increase in the temperature to 25°C reduced the enzyme activity by 28%, while a decrease in the temperature to 20°C caused 17% reduction. Static flask culture favored the dextransucrase production as compared to the shaken flask culture. The enzyme activity in the static flask was 30% higher than the activity in rotary shaken flask culture. The dextransucrase was purified by three successive steps of precipitation using PEG 400. Purified dextransucrase exhibited maximum activity at 30°C, pH 5.2 and 10% of the substrate sucrose. Among the various stabilizers used (glycerol, PEG 8000, dextran and tween 80), glycerol provided maximum stability to the enzyme against the activity losses at temperatures 0°C and 30°C.
Enhancement of the bacterial degradation of phenoxyalkanoate herbicides by the use of modified polyurethane foam as a support
Authors: Hinteregger Christel , Loidl Michael , Stockinger Johannes , Streichsbier Franz 
Published: February 2007

AbstractThe enhancement of the degradative behaviour of Flavobacterium sp. MH concerning the phenoxyalkanoate herbicides 2,4‐D, 2,4‐DP, 2,4‐DB, MCPA, MCPP, and MCPB, respectively, was achieved by the use of an inert polyurethane (PU)‐foam. In comparative batch‐degradation experiments with and without the addition of the PU‐carrier (1.25 % w/v), respectively, the advantages of the PU‐supply were demonstrated. When 2,4‐D, 2,4‐DP, and MCPP, respectively, was used as a growth substrate by strain MH the PU‐supply led to a reduced lag‐phase. In the case of the stronger toxic phenoxyalkanoates 2,4‐DB and MCPB, respectively, the inital substrate concentration (0.1 g/1) was significantly reduced to a minor toxic concentration due to a distinct adsorption to the PU‐carrier, thus enabling the biodegradation. Finally, the total initially supplied amount of the phenoxyalkanoates was detoxified as verified by thechloride balance. After several steps of subcultivation, even a five‐fold increased MCPB concentration (0.5 g/1) could be detoxified by strain MH in a PU‐supplied bubble reactor within several days.
Characteristics of NaCl stress associated proteins of Rhizobium under varying cultural conditions
Authors: Natarajan K. , Kishore L. , Babu C. R. 
Published: February 2007

AbstractSodium chloride stress results in the possible induction of high molecular weight proteins and elevated levels of already existing proteins. These proteins are cytosolic and acidic in nature and are not induced by heat stress. It appears that the cell envelope in DDSS 69 may play a limited role in osmotolerance. Osmoprotectants betaine and glutamate have differential effects on the stress proteins at elevated osmolarities.
Host‐phage interactions under osmotic stress in Nostoc muscorum
Authors: Pandey U. , Singh S. P. 
Published: February 2007

AbstractCyanophage N‐1 multiplication in Nostoc muscorum exposed to osmotic stress was studied. Osmotic stress (0.1 M NaCl, 2–8 h), reduced the host photosynthesis and nitrogenase activity. Latent period of the virus was extended followed by a significant reduction in burst size. The deployment of osmo‐tolerant host and a osmoprotective agent, glycine betaine (1 mM), improved cyanophage yield. The observations form the first report of cyanophage multiplication in a cyanobacterium exposed to osmotic stress and modifications by a osmoprotective agent or by a osmotolerant host.
Fast dissociation of phe‐tRNA synthetase from Aspergillus nidulans immobilized on sepharose‐6B column by NaCl
Authors: Singh Nalin Kumar , Tiwary Bhupendra N. 
Published: February 2007

AbstractPhenylalanyl‐tRNA2) synthetase from Aspergillus nidulans was efficiently immobilised to sepharose 6B column containing phenylalanine as the ligand. NaCl was found to be a potent dissociating agent for the immobilised enzyme. While 0.5 M NaCl in discontinuous elution showed a slow impetus on dissociation giving a plateaux profile, a solution of 0.8 M NaCl made the eiution rapid giving a sharp peak. On the other hand, in a gradient (continuous) elution the rapidity of dissociation was found to be enhanced with the increase in the difference of the two concentrations. The result suggests that Na+ ions interact with the protein binding site of the ligand eventually dissociating the enzyme molecule by disrupting the covalent bond without affecting its normal catalytic activity.
Synthesis and secretion of recombinant penicillin G acylase in bacterial L‐forms
Authors: Gumpert Johannes , Cron Heinrich , Plapp Roland , Niersbach Helmut , Hoischen Christian 
Published: February 2007

AbstractL‐form strains of Proteus mirabilis and Escherichia coli lacking the cell wall represent an alternative prokaryotic cell system for the production of recombinant proteins (KLESSEN et al. 1988, LAPLACE et al. 1988 a, 1989b). We could demonstrate that they are also able to synthesize the enzyme penicillin G acylase (PAC)1). PAC was processed and secreted into the medium by recombinant L‐form strains. The synthesis of PAC was growth‐associated and stably regulated. Expression, secretion, and processing were not temperature‐dependent and occurred at 26 °C, 32 °C and even 37 °C. The expression vector pHC1 carried the pac gene under the control of the lac UV promoter and a kanamycin resistance gene. It could be maintained in L‐form cells, showing low structural as well as segregational instability. The secretion of the biologically active enzyme into the medium indicated that the postranslational processing of the PAC molecule, including the excision of a 54 amino acid spacer peptide between the α and β subunit, is not carried out in the periplasmic space, but occurs at the cytoplasmic membrane or autocatalytically.
Low energy gain from formate oxidation during bacterial growth on 2,4‐dichlorophenoxyacetic acid
Authors: Müller Roland H. , Babel Wolfgang 
Published: February 2007

AbstractAlcaligenes eutrophus JMP 134 was chemostatically grown on 2,4‐dichlorophenoxyacetic acid (2,4‐D) at a dilution rate of 0.06 h−1; formate was fed as an auxiliary energy source. The simultaneous utilization of both components resulted in an increase in growth yield. As an example, this figure increased from 0.18 g dry mass/g 2,4‐D to 0.25 g dry mass/g 2,4‐D during growth on 1 g/l 2,4‐D plus 3 g/l sodium formate. The increase was correlated to energy generated from formate oxidation. Accordingly, a P/O‐quotient of 1 was derived for the energy transduction of NADH obtained from formate oxidation as it was for the overall efficiency during growth on 2,4‐D itself. This low energy yield was attributed to uncoupling exerted by 2,4‐D. The theoretical maximum yield coefficient of 0.69 g/g could not be reached due to the limiting activity of formate dehydrogenase in the conversion of the required quantities of formate.
Bacterial diversity at surface water in three locations within the Baltic sea as revealed by culture‐dependent molecular techniques
Authors: Hantula Jarkko , Koivula Teija T. , Luo Cheng , Bamford Dennis H. 
Published: February 2007

AbstractDiversity of culturable bacteria inhabiting the Baltic sea surface waters was studied in three separate locations. Based on electrophoretically separated whole cell proteins the number of operational taxonomic units (OTU) within each sampling location was high. Most of the OTUs were unique to single locations. Within each sampling location 8–22% of isolates belonged to a single OTU. Rarefaction analysis revealed that the bacterial community was more divergent at a polluted location than at clean areas. Also the most common OTUs were different in clean locations compared to the polluted site suggesting that both diversity and species composition of the bacterial community is greatly affected by pollution. The partial 16S rRNA gene sequences of the isolates of the most common OTUs are unique. Intragroup variation and an OTU‐specific bacteriocin system was observed among the isolates of the second common OTU. The bacteriocin activity was linked to restriction fragment length polymorphism grouping, although additional variation correlating to geographic origin of isolates was observed.
Xylose reductase and xylitol dehydrogenase activities of D‐xylose‐xylitol‐fermenting Candida guilliermondii
Authors: Silva S. S. , Vitolo M. , Pessoa A. , Felipe M. G. A. 
Published: February 2007

AbstractThe effect of the inoculum age and initial xylose concentration on the activities of xylose reductase (XR) and xylitol dehydrogenase (XD) of Candida guilliermondii FTI 20037 were investigated. Under the experimental conditions used, the XR and XD activities were, respectively. NADPH and NAD or NADP dependent. The NADP/NADPH ratio for XR was not substantially influenced by the age of inoculum or the initial xylose concentration. The Km of XR (0.18 M) was about 4‐folds smaller than the Km of XD NAD‐dependent. A renewable xylose‐xylitol conversion was obtained with 40 h aged inoculum of Candida guilliermondii FTI 20037 grown in a medium containing an initial xylose concentration of 120g/l.