bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescent Pseudomonads—a Residual Component in the Soil Microflora?
Authors: Rovira A. D. , Sands D. C. 
Published: March 2008

Summary.The distribution of fluorescent pseudomonads in 2 field soils was studied using a selective agar medium. The fluorescent pseudomonads were distributed unevenly through the soils, their presence being associated with particulate organic matter. Inorganic soil particles and 5 mm aggregates in one soil were devoid of fluorescent pseudomonads.The highest number of fluorescent pseudomonads occurred on partly decomposed wheat straw in contact with wet soil. The population of fluorescent pseudomonads was less in more decomposed plant debris. Fluorescent pseudomonads made up 5·6% and 0·2% of the population of aerobic bacteria on living wheat roots and in soil shaken from the roots respectively.
The Adansonian Taxonomy of Some Cannery Flavobacteria
Authors: Byrom N. A. 
Published: March 2008

Summary.Two hundred and fortyfive isolates of cannery flavobacteria and 5 reference strains were compared by 96 morphological, colonial, physiological and biochemical tests. The results were subjected to computerized Adansonian analysis to investigate the possibility that such bacteria constitute a phenetic taxon. Three pleista are postulated.
Production of Flavour‐enhancing Materials by Streptomycetes: Screening for 5′‐Nucleotides
Authors: Schwartz J. , Margalith P. 
Published: March 2008

Summary.Streptomycetes were examined for their ability to accumulate flavour‐enhancing nucleotides. An efficient screening programme was devised for the isolation of streptomycetes excreting 5′‐nucleotides. Less than 0.7% of these organisms isolated from nature showed appreciable extracellular accumulation of 5′‐nucleotides, and streptomycetes derived from culture collections gave none. In shake flask experiments the yields of nucleotides were minimal and did not exceed (g/l) 0.2 of inosine 5′‐monophosphate, 0.15 of xanthosine 5′‐monophosphate, and 0.05 of guanosine 5′‐monophosphate.
Interaction of Glutaraldehyde with Spheroplasts of Escherichia coli
Authors: Munton T. J. , Russell A. D. 
Published: March 2008

ABSTRACT.Glutaraldehyde, in the presence or absence of sodium bicarbonate, caused an increase in the optical density of spheroplasts of Escherichia coli. The aldehyde, particularly at alkaline pH, prevented lysis of spheroplasts when these were suddenly exposed to a hypotonic environment. It is proposed that the stabilization which occurs results from the crosslinking activity of glutaraldehyde on the cell envelope of E. coli.
Production of Lipase by Staphylococcus aureus under Various Growth Conditions
Authors: Mates A. , Sudakevitz D. 
Published: March 2008

ABSTRACT.Staphylococcus aureus produces an extracellular lipase in a synthetic medium. The composition of the medium affected the amount of enzyme produced: medium containing 2% of peptone was optimal for enzyme production. Tweens added to the media decreased the amount of lipase synthesized depending on the concentration used and the nature of the fatty acid bound to the molecule of polyoxyethylene sorbitan. Carbohydrates that the bacteria could metabolize inhibited lipase production. Bile salts and NaCl decreased the amount of enzyme produced. Optimum lipase production was at pH 7·5 and 37°. The conditions for synthesis of staphylococcal lipase are similar to those described for other bacterial lipases and different from those described for fungi.
A Rapid Technique for Obtaining One‐step or Multi‐step Antibiotic Resistant Mutants Employing Mutator Strains of Escherichia coli K12
Authors: Mount D. W. , Moody E. E. M. , Lew N. , Walker A. 
Published: March 2008

ABSTRACT.A rapid technique is described for obtaining one‐ or multi‐step antibiotic resistant mutants from mutator strains of Escherichia coli K12. The method may be used to test the ability of E. coli to mutate to resistance to increasing concentrations of antibiotics which have not been tested previously. The method has been used to obtain multi‐step mutants which are resistant to high concentrations of polymyxin B.
Studies on the Affinity of Methanol‐ and Methane‐utilizing Bacteria for their Carbon Substrates
Authors: Harrison D. E. F. 
Published: March 2008

ABSTRACT.Methanol‐ and methane‐utilizing organisms were grown in chemostat culture and the response of respiration rate to different concentrations of substrate was measured. Cells of Pseudomonas extorquens NCIB 9399 grown on methanol demonstrated a high affinity for methanol (Km=20·4 μM). The affinities for formaldehyde and formate were 104 μM and 228 μM, respectively. The maximum respiration rate was similar for all 3 substrates. Methanol concentrations of < 1·1 M did not inhibit respiration. The concentrations of formaldehyde that inhibited respiration were > 100 times the Km for formaldehyde so that inhibition by formaldehyde formed as an intermediate in methanol oxidation would be very unlikely. The Km for methane of a culture of a pseudomonad grown on methane was very low, 26 μM; that of the same organism for methanol was 50 μM. The maximum respiration on methanol was c. twice that on methane so that no methanol accumulation would be expected in a methane limited chemostat culture of this organism.
Gradient Elution of Salmonella typhimurium and Escherichia coli Strains from a DEAE‐Cellulose Column
Authors: HALL A. N. , HOGG S. D. , PHILLIPS G. O. 
Published: March 2008

A good separation of cells of Salmonella typhimurium ATCC 14028 and Escherichia coli NCIB 8134, which had been grown on nutrient agar for 18 h at 37 °C, was obtained by elution from a column of Whatman DE‐32 cellulose with a linear NaCl gradient in 0.05 M‐phosphate at pH 6.0.2. The identity of the separated fractions was established by comparison with the elution patterns of the individual bacteria and by means of diagnostic tests.
Salmonella typhimurium cells separated into two fractions under these conditions.
The yield of cells recovered from a column was considerably increased by inclusion of 0.05% (w/v) Tween 80 in the eluant system.
Isolation of Actinomycetes and Fungi from Mouldy Hay using a Sedimentation Chamber
Authors: LACEY J. , DUTKIEWICZ J. 
Published: March 2008

Actinomycetes and fungi causing farmers’lung and infections in man and animals were isolated preferentially using an Andersen sampler after shaking spores from mouldy hay in a sedimentation chamber.
Actinomycetes were isolated after 2 h sedimentation and Aspergillus fumigatus and Absidia spp. after 30 min.
A Simple and Sensitive Technique for Determining the Fermentation Reactions of Non‐sporing Anaerobes
Authors: PHILLIPS K. D. 
Published: March 2008

A new technique is described for determining the fermentation reactions of non‐sporing anaerobes.
The fermentation reactions are carried out on horse blood agar plates to which fermentable substrates are added.
The technique is simple, sensitive and yields reproducible fermentation patterns.
The Thermal Denaturation of Partly Purified Bacterial Deoxyribonucleic Acid and its Taxonomic Applications
Authors: OWEN R. J. , LAPAGE S. P. 
Published: March 2008

Partly purified DNA and the corresponding highly purified DNA was obtained from 25 strains of Gram negative, rod‐shaped bacteria.
The DNAs were examined by the thermal denaturation method and the melting temperatures of both partly and highly purified DNA samples from the same strain were in close agreement.
For all strains, the mean difference in G+C contents estimated from the melting temperatures of each partly and highly purified DNA was 0.4% G+C.
The presence of residual RNA and protein in the partly purified DNA samples contributed to variations in the total hyperchromism but did not significantly affect the accuracy of the melting temperature determination.
The Cultivation of the Rumen Ciliate Entodinium longinucleatum
Authors: OWEN R. W. , COLEMAN G. S. 
Published: March 2008

Two isolates of Entodinium longinucleatum have been cultured in vitro for at least six months in the presence of bacteria on a reduced buffered salts medium with the daily addition of starch grains and ground dried grass.
Cultures of Entodinium longinucleatum were normally maintained by dilution, twice each week, with an equal volume of fresh medium, but the protozoa would also grow from a 2.5% inoculum with a mean generation time of 1.3 days.
Feasibility of Thin Layer Chromatography as an Inexpensive Alternative to Gas‐Liquid Chromatography for the Identification of Some Anaerobic Gram Positive Non‐sporing Rods
Authors: PALASUNTHERAM C. , DRUCKER D. B. , TUXFORD A. F. 
Published: March 2008

Thin‐layer chromatography (TLC) was employed as an alternative to gas‐liquid chromatography (GLC) for the analysis of typical fermentation end‐products of anaerobic Gram positive non‐sporing bacteria. The inexpensive TLC method succeeded in differentiating Actinomyces, Bifidobacterium, Lactobacillus and Propionibacterium.
Ether extraction of supernatant was found to be unnecessary; volatile and non‐volatile acids were separated simultaneously, with consequent saving of time.
A Note on the Effect of Different Types of Agar on the Recovery of Heated Escherichia coli K‐12
Authors: PELLON JOSE R. , GOMEZ REINALDO F. 
Published: March 2008

Escherichia coli K‐12 plated immediately after heat treatment yielded higher plate counts on a minimal medium solidified with Agar Purified (Difco) than on the same medium containing Bacto‐Agar (Difco).
It was concluded that the heat resistance of bacteria can be evaluated only with the use of agar media that are known to be non‐inhibitory to the test organisms after heat treatment.
Isolation and Characterization of Uracil‐Degrading Clostridia from Soil
Authors: MEAD G. C. , ADAMS B. W. , HILTON M. G. , LORD P. G. 
Published: March 2008

Five strains of uracil‐degrading clostridia were isolated from soil using an enrichment medium containing uracil as the principal energy source. All the isolates resembled Clostridium glycolicum, although they lacked the characteristic ability to ferment ethylene glycol.Both representative isolates and a reference strain of Cl. glycolicum degraded uracil and produced β‐alanine when grown in a semi‐defined medium. Thus, the uracil‐degrading activity was similar to that described previously for Cl. uracilicum.
Changes in Heat Resistance During Storage of Bacillus stearothermophilus Spores from Complex and Chemically defined Media
Authors: ALPIN S. J. , HODGES N. A. 
Published: March 2008

Spores of Bacillus stearothermophilus produced on a glucose depleted defined medium and on a complex medium exhibited a loss of viability and a marked reduction in heat resistance as a result of freezing (–18°C) and freeze drying. Little further change in heat resistance occurred during subsequent storage under these conditions.
Spores from the defined medium exhibited an increase in heat resistance during sto1rage as aqueous suspensions for three months at 22°C and 4°C; the resistance of spores from a complex medium was unchanged.
An Electrophoretic Study of Peptidases in Starter Streptococci and in Cheddar Cheese
Authors: CLIFFE A. J. , LAW B. A. 
Published: March 2008

A modified electrophoretic starch gel technique was developed and applied to the detection of peptidase activity in zymograms of crude extracts of Group N streptococci and extracts of cheese made with these organisms. The method required only 0–36 mg of peptide substrate for each test. Dipeptidase, tripeptidase and aminopeptidase activities were detected in strains of Streptococcus cremoris and Strep, lactis and in curds and cheeses made with these organisms.Intracellular and extracellular fractions of Strep, lactis showed similar peptidase activity but with Strep, cremoris there were fewer peptidases in extracellular fractions. The peptidase composition of curd and cheese extracts of different ages was dependent upon the strain and species of starter streptococcus used in making the cheese.
Chromogenic Assay Method of Lipopolysaccharide (LPS) for Evaluating Bacterial Standing Crop in Seawater
Authors: MAEDA M. , TAGA N. 
Published: March 2008

A chromogenic method, based on amoebocyte lysate of horseshoe crab and amino acids‐para‐nitroanilide substrate was employed to quantify lipopolysaccharide (LPS) as a measure of the bacterial standing crop in seawater. The range over which LPS could be reliably determined by this method was from 0.2 to 10 ng/ml of sample, and the method reported here could have several advantages compared with the turbidity determination method.Vertical distributions of total and particulate LPS were parallel in seawater column. Particulate LPS was not shown to be related to the biomass of total bacteria in some cases, but correlated with the numbers of large bacterial cells whose size was greater than 1 fan in length.In most of the profiles investigated in the shallow sea there was no parallel relationship between LPS and chlorophyll‐a whereas in some cases the profiles were similar.In growing cultures of Vibrio anguillarum the content of cellular LPS as a percentage of the total cellular carbon during the 3 d growth ranged from 6–15% (w/w).
Growth of Cutaneous Propionibacteria on Synthetic Medium; Growth Yields and Exoenzyme Production
Authors: HOLLAND K. T. , GREENMAN J. , CUNLIFFE W. J. 
Published: March 2008

A synthetic medium containing only low molecular weight components has been developed to grow Propionibacterium acnes (P. acnes), P. avidum and P. granulosum.The medium supported the growth of 30/32 typed strains, and when solidified with agar supported the growth of these bacteria isolated directly from the skin. The mean overall efficiency of isolation on the synthetic medium was 57% that of reinforced clostridial medium (RCM).Batch culture experiments with glucose, fructose, glycerol or arginine in the medium showed that the concentrations as well as the type of carbon energy sources used could effect growth and exocellular enzyme production by these organisms.
Development of a Selective Medium for the Isolation of Clostridium sporogenes and Related Organisms
Authors: FRYER T. F. , MEAD G. C. 
Published: March 2008

An attempt was made to develop a selective isolation medium for Clostridium sporogenes and related organisms based on the ability of these organisms to obtain their energy for growth by means of coupled oxidation‐reduction reactions between appropriate pairs of amino acids (Stickland reaction). Using a semi‐defined basal medium containing various combinations of amino acids, it was found that Cl. sporogenes utilized a wider range of amino acid pairs than strains of five other species of clostridia known to carry out a Stickland‐type fermentation.With alanine and proline as the principal energy sources and the medium solidified with agar. it was shown that reference strains of Cl. sporogenes and proteolytic Cl. botulinum types A, B and F could be recovered almost quantitatively, with or without prior heating at 80 °C for 10 min. By contrast, growth of test strains of Streptococcus faecalis, Strep. faecium, ‘saccharolytic’Cl. botulinum types B, C, D, E and F and ‘proteolytic’ strains of types C and D was suppressed on this medium, as were strains of 26 other species of clostridia.Addition of 50 μg/ml of polymyxin to the agar medium had no detectable effect on the recovery of Cl. sporogenes or Cl. botulinum. When samples of soil and mud were plated on the antibiotic‐containing medium, 63.1% of 225 isolates thus obtained were identified as Cl. sporogenes/botulinum.
Antibiotic and Heavy Metal Resistance of Pseudomonas aeruginosa Isolated from Soils
Authors: MARQUES ANA M. , CONGREGADO F. , SIMONPUJOL DOLORES M. 
Published: March 2008

1. 71 strains of Pseudomonas aeruginosa were isolated from soils and tested for resistance to antibiotics and heavy metals.2. 6% were resistant both to 12/14 drugs and 9/12 heavy metals tested.
Fimbriae and Haemagglutinins in Erwinias of the Carotovora Group
Authors: CHRISTOFI N. , WILSON MARGARET I. , OLD D. C. 
Published: March 2008

1. Thirteen Erwinia carotovora strains produced mannose‐sensitive haemagglutinins associated with the presence of type‐1 fimbriae.2. Three fimbriate Er. rhapontici strains produced haemagglutinins of the mannose‐resistant and eluting (MRE) type.3. There were 12 Er. carotovora, 12 Er. atroseptica and 2 Er. chrysanthemi strains that produced no detectable haemagglutinins and were non‐fimbriate.
The Fungal and Bacterial Flora of Stored White Cabbage
Authors: GEESON J. D. 
Published: March 2008

1. The predominant organisms isolated from the outer wrapper leaves of freshly harvested white cabbages were: bacteria, yeasts, Alternaria spp., Aureobasidium pullulans, Botrytis cinerea, Cladosporium spp. and Penicillium spp.2. Few qualitative or quantitative changes were seen in the leaf surface flora during storage at 2°C for up to 33 weeks.3. Numbers of bacteria, particularly fluorescent and pectolytic pseudomonads, were considerably higher on cabbages drenched with fungicide or water than on corresponding undrenched cabbages.
Observations on the Value of a Swab Technique for Determining the Bacteriological State of Milking Equipment Surfaces
Authors: RICHARD J. 
Published: March 2008

The reproducibility and efficacy of a swab technique for milking equipment in normal use was studied. Reproducibility was satisfactory when swabbing was done by trained personnel. It was confirmed that swabs pick up only a proportion of the microorganisms present on a surface; this proportion varies with the consistency of the contaminating material, but not with the type of surface on which it occurs. It is concluded that swabs allow the estimation of the maximum ability of a surface to contaminate the milk.Rigid smooth surfaces of the milking machine are recontaminated by microorganisms originating from joints and complex parts of the machine during rinsing after cleaning. A procedure to evaluate the efficacy of cleaning these surfaces is proposed.
Comparison of the Effects of Liquid Medium Repair and the Incorporation of Catalase in MacConkey Type Media on the Recovery of Enterobacteriaceae Sublethally Stressed by Freezing
Authors: MOSSEL D. A. A. , VELDMAN A. , EELDERINK INEKE 
Published: March 2008

Nine pure cultures of species of Enterobacteriaceae were stressed by rapid freezing in tryptone soya broth (TSB) to — 22°C and subsequent storage at that temperature for 7 d. About one to two log cycles kill and at least one additional log cycle sublethal impairment was achieved. Numbers of colonies of these cultures in poured plates of violet red bile glucose (VRBG) agar, with 67 u/ml of catalase added at 47°C, were only slightly higher than those in plain VRBG, both incubated overnight at 30°C. Two hours incubation of TSB suspensions at 17–25° C resulted in almost complete restoration of the ability of cells to develop colonies in VRBG, without, however, leading to any significant multiplication.Similar experiments with 32 samples of frozen minced meat, 27 samples of frozen surface water, 18 of frozen chicken liver and 14 of fresh sausage substantiated the results obtained in the studies on pure cultures.In the experiments with the nine pure cultures the influence of the nutrient composition of the solid enumeration media: ‘minimal’ agar, TSB agar (TSBA) and Mueller‐Hinton agar with Polyvitex nutrient supplement (MHA), on the recovery of Enterobacteriaceae stressed by freezing was also studied. Colony numbers in TSBA and MHA were virtually identical. The glucose mineral salts medium led to lower recovery, indicating that so‐called ‘minimal medium recovery’ of stressed bacterial populations is not a common phenomenon.
Microbiological Parameters for Differentiating between Coastal and Open Waters in the Northern Baltic Proper and the Gulf of Finland
Authors: VÄÄTÄNEN P. 
Published: March 2008

The abundance of selected types of micro‐organisms was compared between seven sites in inshore and offshore areas in the northern Baltic proper and at the entrance to the Gulf of Finland. The aim was to find out which of the microbiological parameters indicate terrestrial and littoral influences on the sites investigated and which of them indicate offshore conditions. During four cruises in 1977–78, samples were collected from 1‐0 m depth, within one or a few days, at five offshore and two inshore sites.Microbial numbers decreased consistently with increasing distance from the shore. The influence of terrestrial runoff, outflows from littoral areas and sediments was clear in the two Tvärminne inshore areas but not in the Ajax area situated about 10 km seaward of the outermost skerries of the Tvärminne archipelago. The influence of these factors was most distinctly indicated by viable bacteria at 18°C and polymyxin‐resistant bacteria, rods and bacterial spores. Offshore characteristics were indicated by vibrios and bacteria obviously in a starved state. Proteolytic bacteria and yeasts did not indicate either of these conditions.
Taxonomy and Description of Vibrio fluvialis sp. nov. (Synonym Group F Vibrios, Group EF6)
Authors: LEE J. V. , SHREAD P. , FURNISS A. L. , BRYANT T. N. 
Published: March 2008

A numerical taxonomic study has been carried out to establish the relationship of group F to other biochemically similar organisms within the family Vibrionaceae. A total of 154 strains were examined including 59 of group F. Out of 114 characters determined for each strain 100 were used to compute average Euclidean distances between strains. Four methods of clustering were used, all of which gave very similar results.Strains resembling Vibrio anguillarum fell into clusters corresponding to V. anguillarum, Beneckea nereida and a previously unrecognized group, phenon 5. Strains of the Aeromonas hydrophila/punctata group formed a heterogenous phenon within which certain subdivisions, perhaps artificial, could be discerned.Group F strains all fell in one closely‐knit cluster distinct from all the species of Vibrio, Aeromonas, Plesiomonas and Photobacteriwn studied. Group F strains could be divided into two biovars, I and II. Both biovars are present in aquatic, particularly estuarine, environments throughout the world but biovar I strains have also been isolated from humans with diarrhoea. It is concluded that group F is a synonym of group EF6 and that the strains within these groups should be classified in a new species named Vibrio fluvialis. The type strain is NCTC 11327.