bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid identification and differentiation of yeasts by DNA and PCR fingerprinting
Authors: Lieckfeldt Elke , Meyer Wieland , Börner Thomas
Published: February 2007

We 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

The 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

The 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

The 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

The 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

Photosynthetic 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

The 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

Treatment 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.
Pseudomonas acidovorans: a bacterium capable of mineralizing 2‐chloroaniline
Authors: Hinteregger Christel , Loidl Michael , Streichsbier Franz
Published: February 2007

Prolonged adaptation of Ca‐alginate immobilized cells of Pseudomonas acidovorans CA28 to a mixture of 3‐chloroaniline (3‐CA)1) and 2‐CA and subsequently to 2‐CA as sole substrate led to the isolation of another strain, termed CA50 with the additional capability of utilizing 2‐CA as sole source of carbon, nitrogen, and energy. Batch‐degradation of 190 mg/l of 2‐CA at pH 6.1 by this newly isolated strain was achieved within 3 days, at higher concentrations up to 0.6 g/l increasing lag‐phases and degradation periods were observed. Except chloride and ammonium no further metabolites were detectable in the medium. Mineralization of 2‐CA proceeds via the modified ortho‐cleavage pathway as demonstrated by the presence of catechol 1,2‐dioxygenase (C120) activity, which is characterized by its substrate specificity and elution behaviour on DEAE‐cellulose.
Principal characteristics of α‐galactosidase from Leuconostoc mesenteroides subsp. mesenteroides
Authors: Huang D. Q. , Prévost H. , Diviès C.
Published: February 2007

α‐Galactosidases (α‐gal) from six strains of Leuconostoc mesenteroides subsp. mesenteroides, which were isolated from four different ecological niches, have been characterized. The enzymes have an optimum pH ranging from 5.5 to 6.4. Strain 19A possesses a pH optimum close to neutral. The optimum temperature varied with the strains, ranging from 37 to 43 °C. The Km values of the enzymes for substrate p‐nitrophenyl‐α‐D‐galactopyranoside (PNPG) varied from 2.15 to 22.70 mM. α‐Gal from strain 23A had the lowest affinity for substrate PNPG. An increase of the affinity for PNPG in the presence of 10 mM lactose was observed for strains 6M, 19A, 23A, 19M, while this higher affinity for PNPG was also observed in the presence of 10 mM galactose for strains 6M, 23A, 19M. The activation energy of the enzyme from different strains was calculated to be about 62.9–72.8 kJ/mol. Ca2+ ions have a strong inhibitive effect on the enzyme activity. Appearance of α‐gal activity band and protein profiles under the same conditions of SDS‐PAGE allowed an estimation of the apparent molecular weight of α‐gal to be at about 175,000.
Natural occurrence of mycotoxins in broad bean (Vicia faba l.) seeds and their effect on Rhizobium‐legume symbiosis
Authors: Mahmoud A.‐L. E. , Abd‐Alla M. H.
Published: February 2007

Seeds of faba bean cultivar Giza 3 were screened for natural presence of mycotoxins. Eleven out of 100 samples were contaminated. Aflatoxins B1 and B2 were found in 7 samples while aflatoxins B1, B2, G1 and G2 and ochratoxin A were each detected twice in separate samples. Mycotoxins at concentrations of 100 or 200 μg kg−1 soil significantly decreased nodule number, nodule fresh weight and total nitrogenase activity, leading to reductions in dry matter accumulation and nitrogen yield of the bean. Mycotoxins also suppressed specific nitrogenase activity. NADH‐dependent glutamate dehydrogenase (NADH‐GDH) as well as glutamate synthase (NADH‐GOGAT) activities. In addition, mycotoxins inhibited synthesis of leghaemoglobin, carbohydrated and protein in the nodule cytosol. Of the mycotoxins tested, aflatoxin B1 was the most toxic. The decline in nitrogenase activity and total N concentration in the plants could be attributed to mycotoxins interference with normal nodule physiology and function.
Microbial degradation of phloroglucinol and other polyphenolic compounds
Authors: Armstrong S. M. , Patel T. R.
Published: February 2007

Biodegradation of phloroglucinol (1,3,5‐trihydroxybenzene) and other polyphenolic compounds by microbes may occur by aerobic and anaerobic metabolic pathways. Aerobic microbes may initiate the mineralization of phloroglucinol or other polyphenolics by either a reductive pathway, epoxide formation, or a specific hydroxylating mechanism. Cleavage of the various intermediates of phloroglucinol and polyphenolic degradation may occur by intradiol and extradiol mechanisms. The reductive pathway in contrast to other mechanisms utilized by aerobic microbes, seems both cumbersome and energy wasteful. The degradation of lignin and its associated phenolics follows an enzymatic combustion process which resembles a nonspecific enzyme‐catalyzed burning. Anaerobic mineralization of phloroglucinol and its associated polyphenolics by several microbes seems to favour the reductive formation of a dihydrophloroglucinol (1,3‐dioxo‐5‐hydroxycyclohexane), which is cleaved by a specific hydrolase. Mineralization of numerous other polyphenolic compounds by anaerobes seems to utilize phloroglucinol as a central metabolite.
Modulation of the spc operon affects growth and protein secretion in Bacillus subtilis
Authors: Breitling Reinhard , Schlott Bernhard , Behnke Detlev
Published: February 2007

A proximal segment of B. subtilis sec Y gene was placed under the control of the inducible spac promoter Lac repressor system. This fusion was integrated into the chromosomal spc operon of B. subtilis via Campbell‐like reciprocal recombination. The growth of the resulting strain was strongly IPTG dependent. With staphylokinase and α‐amylase as reporter proteins it was found, that the protein secretion capacity of this strain was correlated to the conditions of repression or induction of the chromosomal spac promoter.
Utilization of beet molasses for riboflavin production by Mycobacterium phlei
Authors: Ghozlan H. A.
Published: February 2007

Mycobacterium phlei was tested for its ability to utilize beet molasses as the sole carbon source and produce riboflavin. The crude beet molasses was analyzed and treated in various ways to reduce its heavy element content and to remove the muddy residue. Promising amounts of riboflavin were produced when the organism was cultivated on decationized (resin‐treated) beet molasses. The highest vitamin productivity was achieved by incubating the inoculated medium containing 9% molasses and initially adjusted to pH 6 under shacked condition for 6 days in the dark.
Antibacterial activity of three Leuconostoc strains isolated from vacuum‐packaged processed meats
Authors: Papathanasopoulos Maria Antonia , Hastings John Waugh , Holy Alexander Von
Published: February 2007

One hundred and fifty lactic acid bacteria (LAB) isolated from vacuum‐packaged processed meats were screened for antagonistic activity against various food spoilage microorganisms and foodborne pathogens. Nineteen strains produced bacteriocins active against closely related LAB and Listeria strains. Leuconostoc carnosum (LA54a and TA26b) and Leuconostoc mesenteroides subspecies dextrancum (TA33a) produced bacteriocins that were susceptible to proteolytic enzymes, but not to catalase, lysozyme or chloroform. They were heat stable up to 100 °C for thirty minutes at pH 2 to 7, and exerted a bacteriolytic effect. Bacteriocin production by all Leuconostoc strains was growth associated, occurring at incubation temperatures of 0 °C to 30 °C and initial medium pH 4.5 to 7.5. Probing of plasmid DNA from the three Leuconostoc strains with an oligonucleotide probe homologous to the nucleotide sequence of leucocin A‐UAL 187 indicated plasmid‐mediated bacteriocin production. Homology of the three Leuconostoc bacteriocin‐coding genes to the amino‐terminal end of the leucocin A‐UAL 187 gene from Leuconostoc gelidum UAL 187 is therefore suggested. This evidence implies that all three Leuconostoc strains produce type 2, Listeria active bacteriocins.
Isolation of plasmid pRLI from Arthrobacter oxydans 317 and demonstration of its role in steroid 1 (2)‐dehydrogenation
Authors: Sarman Utpal , Roy Monoj K. , Singh H. Devendra
Published: February 2007

Arthrobacter oxydans 317 capable of complete degradation of β‐sitosterol harbours two plasmids ‐pJLI and pRLI. Standard plasmid isolation methods can easily detect pJLI but not pRLI. The latter plasmid was isolated by a mild procedure using α,α′‐dipyridyl as lytic agent and separated from pJLI by agarose gel electrophoresis using the technique of electro elution into throughs. It's molecular weight was found to be about 3.5 kilo base (kb) pRLI was introduced into the plasmid cured A. oxydans 317 AL. Through genetic transformation using protoplasts of the recepient strain, a transformant strain A. oxydans 317 ALT bearing only pRLI plasmid was obtained. The transformant strain was unable to grow on 4‐androstene‐3, 17‐dione (AD) and 1,4‐androstadiene‐3,17‐dione (ADD) as sole carbon source but a modest growth was observed on 9α‐hydroxy‐4‐androstene‐3, 17‐dione (9α‐hydroxy AD) indicating the ability for steriod 1 (2)‐dehydrogenation and a lack of the capacity for α,α‐hydroxylation. The strain was able to form ADD from AD, and 1 (2)‐dehydrogenation of 3‐oxochol‐4‐en24‐oic acid from β‐sitosterol. Direct estimation of steroid (1 (2)‐dehydrogenase activity showed that the transformant strain and parent strain containing pRLI had high enzyme activity where as strains lacking in this plasmid had negligible enzyme activity. It was concluded that pRLI is responsible for steroid 1 (2)‐dehydrogenation in A. oxydans 317.
Role of glutamine synthetase activity in the urea regulation of heterocyst and nitrogenase formation in the cyanobacterium Anabaena cycadeae
Authors: Singh Surendra , Bisen P. S.
Published: February 2007

Growth and urea regulation of heterocyst and nitrogenase formation have been studied in the diazotrophic cyanobacterium Anabaena cycadeae and its glutamine auxotrophic mutant strain lacking glutamine synthetase (GS) activity. The parent strain having normal GS activity utilized urea as sole nitrogen source without producing N2‐fixing heterocysts. In contrast, the mutant strain lacking GS activity could not utilize urea as sole nitrogen source although similar to the parent strain it lacked N2‐fixing heterocysts in urea‐medium. Both parent and mutant strain showed high levels of urea uptake and urease activity in the presence and absence of a GS inhibitor, l‐methionine‐dl‐sulphoximine (MSX). Urea‐dependent NH production by MSX‐untreated cells was only confined to the mutant strain lacking GS activity whereas the parent strain having normal GS activity produced NH only in the presence of MSX. These results suggest that (i) GS is the sole NH assimilating as well as glutamine‐forming route in heterocystous N2‐fixing cyanobacteria; (ii) while GS activity is necessarily required for the assimilation of urea as sole nitrogen source, it is however, not required for the urea inhibition of heterocysts and nitrogenase formation; (iii) that NH resulting from the hydrolysis of urea and not GS‐mediated pathway of NH assimilation appears to be the initial repressor signal for heterocysts and nitrogenase formation; and (iv) GS does not control the formation of N2‐fixing heterocysts, urea uptake and urease activity systems.
Xylitol formation by Candida guilliermondii in media containing different nitrogen sources
Authors: Silva Silvio S. , Mancilha Ismael M. , Queiroz Maurício A. , Felipe Maria G. A. , Roberto Ines C. , Vitolo Michele
Published: February 2007

The xylose conversion into xylitol by Candida guilliermondii was evaluated in semi‐synthetic media supplemented with different nitrogen sources in a ratio C/N equal 25.6. It was noticed that the xylitol yield was around 80% and also that the type of nitrogen source did not influence this bioconversion.
Glutamic acid synthesis from methanol: Theoretical considerations
Authors: Ackermann Jörg‐Uwe , Babel Wolfgang
Published: February 2007

To determine to what extent methanol in addition to the commonly used glucose is an attractive alternative feedstock for glutamic acid production, a comparative theoretical consideration of possible yields is given. Methanol can be assimilated by bacteria via three different metabolic pathways. With regard to the corresponding energy balance equations the overproduction process is either energy‐deficient, energy‐neutral or energy‐excess. The theoretical maximum yields of glutamic acid synthesis with methanol as a substrate are not substantially lower than based on glucose. In one case the value is even higher. From the aspect of possible yields methanol would not be less convenient than glucose and the serine pathway seems to be the most suitable one for the synthesis of glutamic acid.
Influence of growth rate and nutrient limitation on monobactam production and peptidoglycan synthesis in Pseudomonas aeruginosa
Authors: Allison D. G. , Nolan R. D.
Published: February 2007

The effects of growth rate and nutrient limitation on monobactam production, peptidoglycan content and mean cell length in Pseudomonas aeruginosa was studied using continuous culture techniques. All three parameters increased progressively with growth rate, a greater response being shown under carbon limitation compared to that occurring under nitrogen limiting conditions. Interestingly, monobactum production mirrored peptidoglycan synthesis. In addition, the monobactam exhibited a broad range of antibacterial activity and bound preferentially to PBP 1A in the producing organism. Moreover, addition of the monobactam to a growing culture inhibited cell wall synthesis. These results are discussed in relation to the control and regulation of peptidoglycan synthesis.
Action of carbamate biocides on sterols, gibberellin and aflatoxin formation
Authors: Hasan H. A. H.
Published: February 2007

An interrelationship between primary and secondary metabolites of a toxigenic mould(Aspergillus parasiticusvar.globosusIMI 120920) was obtained in liquid broth containing various concentrations of dithaneZ‐78 and propoxur. The results show that a stimulatory response was recorded in gibberellin, protein, sterol and aflatoxin yield in cultures treated with 15, 30, 50 and 100 ppm a.i. of dithane Z‐78. On the other hand, propoxur reduced the yield of gibberellin, amino acids, protein, sterol and aflatoxin. In comparison to its effect on the mycelial growth, gibberellin and aflatoxin activity is inhibited more severly than dry weight increase, thus leading to the assumption that there is a specific effect of the inhibitor on both gibberellin and aflatoxin synthesis.
Development of an inexpensive legume‐Rhizobium inoculation technology which may be used in aerial seeding
Authors: Jha Prakash K. , Nair Suresh , Babu C. R.
Published: February 2007

Encapsulation of seeds with alginate entrapped rhizobia (AER) bead has been developed as a new seed‐applied inoculum technique for utilizing legume‐Rhizobium symbiosis for the management and protection of natural ecosystems. Alginate beads trapped water and immobilized rhizobia which ensured germination of seeds and nodulation of seedlings. Incorporation of a synthetic polymer, Jalshakti, in alginate beads did not enhance symbiotic nitrogen fixation but sufficient number of rhizobia remain viable in them even after 30 weeks of storage reflecting suitability of these materials as carriers for rhizobia. Plant cultures raised from these beads were similar to or even better than the inoculated controls in symbiotic parameters indicating the effectiveness of seed‐applied inoculum technique. Pelleting of seeds with these polymers after coating with gum arabic lead to substantial reduction in symbiotic association and viability of rhizobia. Experiments involving two legume‐Rhizobium associations indicated that the encapsulation of seed with AER bead is a cheap, inexpensive and effective inoculation technique which may be used in aerial seeding.
A revised map location for the histidine utilization genes in Pseudomonas putida
Authors: King Robin S. , Sechrist Lynne L. , Phillips Allen T.
Published: February 2007

The histidine utilization genes hutH and hutU of Pseudomonas putida ATCC 12633 have been mapped by interrupted mating and transduction to a location at approximately 43 minutes on the chromosome, closely linked to ser‐800 and met‐400 markers previously shown to be at 46 and 42 minutes, respectively. Since restriction enzyme mapping and cloning results have established that all genes associated with the hut pathway are contiguous, earlier maps of this strain which place these genes near 10 minutes on the chromosome in a superoperonic catabolic cluster are in error.
Loss of the TOL meta‐cleavage pathway functions of Pseudomonas putida strain PaW1 (pWW0) during growth on toluene
Authors: Brinkmann Ulrich , Ramos Juan L. , Reineke Walter
Published: February 2007

A derivative of Pseudomonas putida strain PaW1 bearing the TOL plasmid pWW0 was isolated from a culture which has grown unlimited on toluene. In contrast to the parent strain PaW1, the derivative, strain CG220, is unable to grow with xylenes and toluates, while toluene and benzoate served as substrates. Strain CG220 had a remarkable growth advantage against the wild type when grown with toluene. Biochemical analysis showed that in strain CG220 toluene was metabolised through the TOL plasmid upper pathway to benzoate and the latter to amphibolic intermediates by the chromosomal encoded ortho‐cleavage pathway. No activities of the TOL plasmid encoded toluate dioxygenase and catechol 2,3‐dioxygenase were detectable in strain CG220. No reversion of strain CG220 to growth with xylenes or toluates was observed. Hybridisation experiments with TOL plasmid‐derived gene probes and oligonucleotides revealed that genes xy/Y to xy/G were absent, while xy/X and xy/K were still present.
Keratinophilic fungi in soils of Yemen Arab Republic
Authors: El‐Said A. H. M.
Published: February 2007

Thirty‐six species belonging to 15 genera of keratinophilic fungi were collected from 50 soil samples gathered from different places of Yemen by using hair fragments as baits at 28 °C. Six species of true dermatophytes were collected:Arthroderma lenticulare(=Trichophyton terrestre), Trichophyton mentagrophytes, T. equinum, T. rubrum, T. soudanenseandMicrosporum gypseum. Numerous Keratinophilic fungi were isolated namely:Aphanoascus terreus(=Chrysosporium indicum), Aphanoascus species( =C. tropicum), A. fulvescens( =C. keratinophilum), Chrysosporium pannicola, C. pruinosum, C. carmichaelii, C. lucknowense, C. xerophilum, C. asperatum, Athroderma cuniculi( =C. anamorphofArthroderma cuniculi),A. curreyi( =C. anamorphofArthroderma curreyi) andPectinotrichum Ilanense( =C. anamorphofPectinotrichum Ilanense). The commonest saprophytes in order of frequency were member of the generaAspergillus, Alternaria, Penicillium, Rhizopus, Cunninghamella, Fusarium, UlocladiumandMacrophomina.
Characterization of a Tn925‐induced mutant of Staphylococcus aureus altered in exoprotein production
Authors: Giraudo Ana T. , Martínez Gabriela L. , Calzolari Aldo , Nagel Rosa
Published: February 2007

An insertional mutant was isolated from a bovine Staphylococcus aureus strain after membrane‐mating with a Streptococcus faecalis strain carrying conjugative plasmid pCF10: : Tn925. This mutant, designated RC128, showed enhanced production of α‐hemolysin and proteases and decreased production of coagulase, extracellular protein A, DNase, lipase and δ‐hemolysin. No difference was found in the production of β‐hemolysin. Both, Southern blot analysis and transfer of the pleiotropic mutant phenotype by transduction, indicated that the mutation was originated from a single insertion of transposon Tn925. The LD50 determined by intraperitoneal administration in mice showed that mutant RC128 was slightly less virulent than its parental strain.
Role of phenolic substances in pathogenesis of soft rot diseases
Authors: Khare V. , Mehta P. , Kachhwaha M. , Mehta A.
Published: February 2007

Phomopsis sapotae and P. psidii are known to cause severe fruit rot diseases of Achras sapota and Psidium quajava fruits respectively. Among all tested phenolic compounds, α‐naphthol (50 ppm) and guaiacol (250 ppm) caused complete inhibition of mycelial growth of Phomopsis sapotae and P. psidii. Achras sapota and Psidium quajava fruits treated with α‐naphthol (50 ppm) and guaiacol (250 ppm) did not show any disease symptoms and hence complete inhibition of polygalacturonase, pectinmethylgalacturonase and cellulase enzyme was recorded in both the fruits. Pyrocatechol and phloroglucinol were least inhibitory in checking the mycelial growth, rot development and enzyme secretion in both the tested fruits. Generally these parameters were decreased by increasing the concentration of each phenolic compound in both the cases.
Influence of some non‐halogenated aromatics on 2,4‐D assimilation by a microbial consortium
Authors: Müller R. H. , Babel W.
Published: February 2007

A microbial consortium capable of converting 2,4‐D with a maximum rate of 0.18 h−1 under chemostatic conditions was shown to be unable to further utilize this compound after nonchlorinated aromatics were simultaneously supplied. After a long term cultivation on aniline and 2,4‐D under chemostatic conditions, 2,4‐D remained almost unmetabolized and the culture could not be reactivated to use 2,4‐D as a sole source of carbon and energy. However, phenol pulses did not disturb growth on 2,4‐D when the latter was supplied in a carbon substrate‐limited manner at a rate lower than that used in the precultivation phase. Phenol even remained unmetabolized after one day of treatment. Wash‐in of phenol to a culture growing on an excess of 2,4‐D did not lead to a disturbance of growth either, but to a sequential consumption of both. These results are discussed in terms of metabolic incompatibility in the conversion of chlorinated and non‐chlorinated aromatics and regulatory threshold concentrations.
A new microbial isoquinoline iron chelator from Streptomyces spec. 2002‐104
Authors: Gräfe Udo , Ritzau Michael , Ihn Wolfgang , Möllmann Ute , Fleck Werner F. , Groth J. , Reissbrodt Reinhardt
Published: February 2007

2‐N‐hydroxy‐3,4‐dihydro‐isoquinoline‐1‐one (C9H9NO2, 1) was isolated as a new naturally occurring iron chelator from cultures of Streptomyces spec. 2002‐104 in the course of a screening for new iron chelating compounds. The structure was solved by high resolution MS and NMR investigations.
Catabolite repression of cellulase biosynthesis in Streptomyces albaduncus
Authors: Harchand R. K. , Singh S.
Published: February 2007

The cellulase complex of S. albaduncus was found to undergo catabolite repression in the presence of glycerol accompanied by a decrease in the pH of the medium. The results of the experiments conducted at two different initial pH of the medium suggested that pH effect as well as proteases were involved in the inactivation of glucanases (exoglucanase and endoglucanase) whereas β‐glucosidase inactivation was solely due to ‘pH effect’. It was also apparent that pH change followed by the addition of glycerol caused alterations in protease activities as well as pattern of their production.
Osmotolerant yeasts isolated from Tokaj wines
Authors: Miklós Ida , Sipiczki M. , Benko Z.
Published: February 2007

Yeasts growing in “Tokaj Aszu” wine and in “Aszu essence” were isolated and characterised. They proved to be physiological races of Saccharomyces cerevislae and showed high osmotolerance, which was an inherited feature rather than the result of adaptation. No correlations were found between the osmotolerance and the ethanol tolerance or the cell size and morphology. Yeasts in “Aszu essence” are usually undesirable contaminants that impair the quality of the essence. The isolate characterized in this work exhibited physiological parameters very similar to those of the “Tokaj Aszu” strain, which make it a potent competitor of other yeasts in Aszu fermentation. However, the high termo sensitivity of its cells offers a possibility to eliminate them selectively.
Social behaviour of microbial populations
Authors: Oleskin Alexander V.
Published: February 2007

This 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

A 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 chymotrypsin

The 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

The 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

Cultivation 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

Low 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

Mycoplana 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

Nitrate 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

In 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

Twenty 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

The 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

Ten 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 above

The 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 cholerae

Caseicin 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

Acinetobacter 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

Two 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

Dextransucrase 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.