bluuebunny/crossref_metadata_2025_split huggingface dataset:
Toxic Subunits of the Crystal of Bacillus thuringiensis
Authors: Pendleton I. R. 
Published: March 2008

SUMMARYProducts of digestion of the protoxin crystals of Bacillus thuringiensis var. berliner by gut juice of larvae of Pieris brassicae were examined by gel filtration, antigenic analysis, electrophoresis and toxicity tests. The digest was separated into 2 fractions; fraction 1 contained a protein of molecular weight > 200,000, and fraction 2 contained a peptide with a molecular weight between 5000 and 10,000. Only fraction 2 was toxic to the insect larvae on injection although both fractions were toxic by feeding. The association of toxicity of fraction 2 with certain antigens is described and a possible relationship between the two fractions is discussed.
Deoxyribonucleic Acid Base Composition of some Marine and Halophilic Micrococci
Authors: Bohaaček J. , Kocur M. , Martinec T. 
Published: March 2008

SUMMARYThe guanine + cytosine (GC) content of the DNA's of 15 strains of marine and halophilic micrococci was determined using the methods of Marmur & Doty (1962) and Frédéricq, Oth & Fontaine (1961), and by paper chromatography. Only 4 strains having 69.3‐72.8% of GC could be considered as members of the genus Micrococcus. Four motile cocci had GC contents of c. 41%: these should be placed in the genus Planococcus. Two strains by their GC contents of 32‐33% belong to the genus Staphylococcus. The GC content of the DNA of the strains of Micrococous morrhuae ranges from 57.1 to 61%.
Fatty Acids of Rhodotorula gracilis: Fat Production in Submerged Culture and the Particular Effect of pH Value
Authors: Kessell R. H. J. 
Published: March 2008

SUMMARYRhodotorula gracilis growing in batch culture exhibited acceleration, exponential and linear phases of growth. In a fourth phase, following nitrogen exhaustion, the concentration of lipid in the culture increased, but it is suggested that the rate of lipid production was not stimulated but remained constant, the apparent increase being almost entirely due to the absence of cell proliferation. No significant changes occurred in the fatty acid composition of the lipid when nitrogen was exhausted. At low pH values, growth of the organism was retarded, but the lipid production rate increased although the final concentration of lipid remained the same. The ratio of unsaturated to saturated fatty acids also decreased principally due to a lowered concentration of oleic acid but the concentration of myristic, stearic, linoleic and linolenic acids increased.
An Improved Method for Determining Cellulolytic Activity in Anaerobic Bacteria
Authors: Mann S. O. 
Published: March 2008

SUMMARYAn improved method for determining cellulolytic activity in anaerobic bacteria is described in which the disintegration of a filter paper strip denotes activity. By inoculating the paper‐containing media from dilutions of material such as rumen contents estimates of the numbers of cellulolytic bacteria in the original material may be made. The method can also be used for determining cellulolytic activity of pure cultures. Morphology and other properties of the bacteria may be determined.
Enumeration of Staphylococcus aureus in Foods with Special Reference to Egg‐yolk Reaction and Mannitol Negative Mutants
Authors: Waart J. De , Mossel D. A. A. , Broeke R. ten , Moosdijk A. van de 
Published: March 2008

SUMMARYChapman's medium designed for the enumeration of Staphylococcus aureus showed three shortcomings: (i) micrococci and many Bacillus spp. grow well on this agar and may obscure colonies of Staph. aureus; (ii) some strains of Staph. aureus fail to dissimilate mannitol; among 1164 strains examined, mostly from clinical sources, 4.4 % appeared unable to dissimilate mannitol; (iii) the agar has inhibitory properties to sublethally impaired cells of Staph. aureus. The latter deficiency not being correctable, the suitability of the egg yolk‐tellurite‐glycine‐pyruvate agar (ETGPA) of Baird‐Parker (1962b) was evaluated. Of 522 strains of Staph. aureus of human and food origin 97.5 % developed characteristically and generally quantitatively on Baird‐Parker's agar.Baird‐Parker's medium has proved valuable in ecological studies on the occurrence and development of Staph. aureus in foods incriminated in staphyloenterotoxicosis: among 165 atypical black colonies isolated from 450 food samples only 2% were Staph. aureus.
Esterases and DNA Base Composition Analysis of Vibrio cholerae and Related Vibrios
Authors: Colwell R. R. , Adeyemo V. I. , Kirtland H. H. 
Published: March 2008

SUMMARYEsterases of strains of Vibrio cholerae, V. parahaemolyticus, noncholera and marine vibrios were examined by electrophoresis in starch gels. The enzyme patterns indicated a relative homogeneity occurring amongst the strains. No separation of the genus Vibrio into subgroups corresponding to the El Tor, classical cholera or noncholera groupings was noted. Overall deoxyribonucleic acid base composition for the Vibrio spp. ranged from 44‐49 mol% guanine + cytosine, with the marine vibrios lowest in guanine + cytosine content. Enzyme patterns for cholera vibrios isolated during very recent epidemics were identical to those of established laboratory strains, suggesting a marked stability of the esterase system for V. cholerae.
Salt Tolerance in Pigmented and Nonpigmented Strains of Bacillus Species Isolated from Soil
Authors: Turner Myfanwy , Jervis D. I. 
Published: March 2008

SUMMARYDifferent methods of estimating growth were used for comparing the salt tolerance of pigmented and nonpigmented strains of Bacillus species isolated from soils. The pigmented strains tolerated much higher concentrations of NaCl than the nonpigmented strains from the same sources.
Nitrogen, Energy and Vitamin Nutrition of Rhizobium japonicum
Authors: Elkan G. H. , Kwik Iem 
Published: March 2008

SUMMARYThe energy, nitrogen and vitamin nutrition of 36 strains of Rhizobium japonicum were investigated. Most of the strains utilized gluconate, glycerol, arabinose, glucose, mannose, mannitol, sorbitol, galactose and maltose. Pyruvate, succinate, ribose, ribitol, xylose, fructose and lactose were of limited use whereas acetate, propionate, lactate, malate, citrate and sucrose were uniformly inadequate as carbon or energy sources. All strains grew well with vitamin‐free casein hydrolysate, and 6 could utilize ammonia as sole nitrogen source. Glutamate was utilized by 33 strains, histidine by 26, aspartate by 20 and proline by 26 strains. Other amino acids were not utilized by most strains. The organisms grew independently of any vitamins except biotin. Three of the strains were stimulated and growth of 4 was inhibited by biotin.
Taxonomy of some Staphylococci and Micrococci Isolated from Bovine Teat Canals and Foremilks
Authors: Forbes D. 
Published: March 2008

SUMMARYThe taxonomy of 2404 cultures of Gram positive, catalase positive, nonmotile cocci was determined using Baird‐Parker's (1963) classification. The bacteria were isolated from bovine teat canals and milk samples during 2 lactations of an experimental herd of cattle and their taxonomic positions were assessed on the basis of 8 reactions. Most were clearly assigned to typical subgroups, although some arabinose positive staphylococci and VP positive and phosphatase positive micrococci were atypical. Cultures representative of these and typical subgroups were examined in more detail using 25 reactions. Most cultures were again classified as being typical but it was shown that the atypical cultures were genuinely different from bacteria examined by Baird‐Parker. A marked difference was found in the results of the phosphatase reaction on Baird‐Parker's phosphatase medium and on that prepared with a different base used in this work. The atypical micrococci gave a negative result when tested on Baird‐Parker's medium but their carbohydrate reactions still differentiated them from other subgroups.Carbohydrate oxidation tests varied in intensity depending on whether the medium was prepared as slopes or plates. The slopes gave a more intense reaction which persisted once a positive reaction occurred. The methods used provide additional means for epidemiological studies of Micrococcaceae in dairy herds.
Effects of Pasteurization or Added Sulphite on the Microbiology of Stored Vacuum Packed Baconburgers
Authors: Gardner G. A. 
Published: March 2008

SUMMARYThe flora of untreated vacuum packed baconburgers which were allowed to spoil at 5, 10 and 22° was dominated by atypical streptobacteria. Corynebacterium spp., micrococci, Bacillus spp. and lactic acid bacteria survived the post‐packing pasteurization treatments. There was no increase in bacterial numbers in 3 weeks at 5°, but at 10 and 22° group D streptococci grew and caused a souring spoilage of the product. Sodium metabisulphite, added to an initial level of 300 p/m SO2 retarded the growth of organisms, but had no qualitative effect on the flora. Of the two methods for extending the shelf life of vacuum packed baconburgers, the addition of SO2 was the safer, as the public health significance of group D streptococci is at present decidedly equivocal.
Anaerobic Gram Negative Nonsporing Bacteria from the Caeca of Poultry
Authors: Barnes Ella M. , Impey C. S. 
Published: March 2008

SUMMARYFour groups (1, 4, 5 and 6) of Gram negative, nonsporing anaerobic rods (family Bacteroidaceae) which have been isolated from the caeca of chickens, turkeys and ducks, are described. Two of the groups (1 and 6) belong to the genus Sphaerophorus but differ in a number of characteristics from named strains. The group 5 strains belong within the genus Bacteroides and resemble Bact. fragilis. The group 4 strains differ from Sphaerophorus and Bacteroides and have not yet been assigned to a genus. The methods used for isolating and identifying these organisms are discussed.
A Note on the Production of Radioactive Sulphide by Desulfovibrio desulfuricans
Authors: Jones‐Mortimer M. C. 
Published: March 2008

SUMMARYA method was developed for the preparation of [35S] cadmium sulphide from [35S] sodium sulphate employing cultures of Desulfovibrio desulfuricans. [35S] H2S may be prepared by the action of 2 N hydrochloric acid on [35S] cadmium sulphide.
Neomycin‐containing Media in the Isolation of Clostridium botulinum and Food Poisoning Strains of Clostridium welchii
Authors: Spencer R. 
Published: March 2008

SummaryMany strains of Clostridium botulinum types A and B and nonhaemolytic food poisoning strains of Cl. welchii were inhibited by 200 μg, but in general not by 50 μg, of neomycin/ml in blood agar or Nagler agar. Cl. botulinum type E was particularly sensitive to neomycin, growth being prevented by a concentration of 25 μg/ml of medium.
Gravimetrical and Mycological Investigations of Soil Suspensions in the Soil Dilution Plate Technique
Authors: Hornby D. 
Published: March 2008

SummaryCertain common methods used for agitating and sampling soil suspensions in the dilution plate method were tested gravimetrically for accuracy and precision and compared mycologically on the basis of colony counts. No method could be relied upon for gravimetrically representative samples and in general methods with high precision were very biased and those with low bias were very variable. Some methods, such as magnetic stirring of soil in a viscous diluent, were better overall methods on the gravimetric criterion. Pipette samples underestimated and dipper samples overestimated the weight of soil in the primary suspension. Continuous agitation during sampling was essential for the highest colony counts and permitting settling for 4–5 min significantly decreased counts. Viscous diluents and other minor refinements were not significant improvements mycologically. In a comparison between a positively biased sampling method and a negatively biased one, transferring only one quarter as much soil from the primary soil suspension, no significant difference in colony counts occurred. The possible interpretations of this are discussed.
Methods of Assessing the Psychrotrophic Bacterial Content of Milk
Authors: Thomas S. B. 
Published: March 2008

SummaryThe various methods used for the determination of the psychrotrophic bacterial content of refrigerated milk are reviewed and assessed. A standard reference method, involving incubation of poured plates at 7° for 10 days, is recommended for the determination of psychrotrophic colony counts for investigational purposes. Many ingenious techniques, based on media selective for Gram negative bacteria, with incubation at higher temperatures and shorter times are described and appraised. A simple procedure which would provide a more rapid assessment of the number of active milk spoilage types of psychrotrophs is needed for routine purposes, and it is suggested that the enumeration of microcolonies by the drop plate or membrane filter methods with incubation at 7° for 72 h would provide a suitable technique for this purpose.Incubation of plates at 25° for 5 days is recommended as a standard reference method for determining the total colony count of bacteria in refrigerated milk, but for routine purposes where large numbers of milk samples are being examined incubation at 28–30° for 3–4 days would provide a sound enough estimate.
Sterilization by Radiofrequency Induction Heating: a Method for the in situ Sterilization of Vessels in Automatic Bacteriological Apparatus
Authors: Trotman R. E. 
Published: March 2008

SummaryA stainless steel pipette and a stainless steel wire were heat sterilized, in 8 and 4 sec, respectively, by radiofrequency induction. The method seems suitable for sterilizing vessels in situ and for general purpose sterilization.
Growth and Sporulation of Clostridium welchii in Breast and Leg Muscle of Poultry
Authors: Mead G. C. 
Published: March 2008

Growth of a heat resistant, food poisoning strain of Clostridium welchii was followed in raw, minced breast and leg muscle of the chicken. Within the range 22–50° growth was slightly more rapid in the leg (pH 6·5–6·7) than in the breast (pH 5·6–5·7) and was fastest in leg muscle at 50°. No growth occurred at 15 or 52°.In a comparison between chicken and turkey, inoculated breast and leg muscle were cooked for 1 h at 85° and held at 37°. Multiplication of surviving organisms was initiated much more rapidly in chicken than in turkey meat, though the growth rates were comparable in each case.Sporulation of several strains of CI. welchii, including other heat resistant, food poisoning types, was generally 10–100 times greater in leg than in breast muscle of the chicken. Differences in sporulation could be attributed both to differences in pH and type of meat.
Isolation and Enumeration of Aerobic Heterotrophic Bacteria in Activated Sludge
Authors: Gayford C. G. , Richards J. P. 
Published: March 2008

Summary.The viable counting of bacteria in activated sludge has been investigated. The surface viable technique was considered satisfactory. The constituents of activated sludge appear to be nutritional requirements for some bacteria present. The deflocculating agents sodium pyrophosphate, sodium citrate and the nonionic surfactant, Lubrol W, facilitated the separation of bacteria from the particulate matter. A combination of sodium pyrophosphate and Lubrol W both at a concentration of 0·01% was very effective in this respect.
Further Studies on the Phage Sensitivity and the Determination of Phytopathogenic Pseudomonas spp.
Authors: Billing Eve 
Published: March 2008

Summary.An interim determinative scheme for phytopathogenic Pseudomonas spp. by a variety of cultural and biochemical tests was suggested by Lelliott, Billing & Hayward (1966) following the study of 156 green fluorescent phytopathogenic pseudomonads. The phage sensitivity of these and 80 additional cultures to 20 phages from a variety of sources are described. Information on the morphology of these phages is now available (Bradley, 1963a). A few nutritional tests which seem to be of diagnostic value at the species level are also included and a relationship between the presence of a heat stable antigen (Lovrekovich et al., 1963) and phage sensitivity patterns is discussed.
A Colorimetric Bioassay Method for Colicins
Authors: Shannon R. , Hedges A. J. 
Published: March 2008

Summary.A technique for the comparative assay of colicin samples is described. Relative potencies are estimated by a modification of the well known survivor count method, in which the lethal potential of samples is measured indirectly by colorimetric determination of their effect on the capacity of a sensitive indicator culture to reduce 2,3,5‐triphenyltetrazolium chloride under specified conditions. The method has (i) simplicity of operation, (ii) a wide range of application, (iii) rapidity of execution, (iv) high sensitivity, (v) good precision.
Residual Bactericidal Action of Wool Blankets Laundered with Formaldehyde: A Hospital Trial
Authors: Dickinson J. C. , Wagg R. E. , Litchfield Susan 
Published: March 2008

Summary.A hospital trial of wool blankets laundered with a 0·38% (w/v) solution of formaldehyde in the last but one rinse showed evidence of residual bactericidal action of the blankets. On removal from the beds after a fortnight's use, dirty treated blankets contained down to one tenth of the number of bacteria present on dirty untreated blankets. There were also fewer dirty treated than control blankets on which coagulase positive bacteria could be detected. Chemical tests showed that the formaldehyde content of the blankets built up to c. 1%. No complaints were received of odour from the blankets.
A Comparison of Methods for Assessing the Value of Antibacterial Soaps
Authors: Wilson Patricia E. 
Published: March 2008

Summary.A new antibacterial soap preparation containing trichlorocarbanilide (TCC) was compared in laboratory tests with a commercially available hexachloraphane soap and a control, nongermicidal soap. Both antibacterial soaps showed significant reductions in the skin flora, contact plate tests revealed no difference between the two preparations. In an 18 months ward trial the transmission of staphylococci was significantly reduced by the TCC soap.
A Comparator Method of Assessing Bacterial Plate Counts
Authors: Murphy R. P. , Tucker C. G. 
Published: March 2008

Summary.The plate count method of assessing total viable counts of bacteria in milk, water, and foods has only a precision of ±25%, and is tedious. In the method here described plate cultures prepared in the usual way are compared visually with a series of standards: the preparation of suitable standards is discussed. By this method it is possible to assess rapidly the numbers of colonies on plates carrying up to 1000 colonies with as little as ±10% error. The speed of examination is virtually independent of the numbers of colonies present.
The Effect of Oxygen on the Germination and Outgrowth of Spores of Clostridium butyricum
Authors: Hambleton R. , Rigby G. J. 
Published: March 2008

Summary.The germination of spores of Clostridium butyricum, the emergence of germ cells and replication of vegetative cells in atmospheres of different oxygen content have been quantitatively investigated by a nutrient agar slide technique. The sensitivity to oxygen of (1) the process of germination, (2) germinated spores or the process of emergence and (3) cellular replication increases progressively.
Aniline Utilization by Alcaligenes faecalis: A Taxonomic Reappraisal
Authors: Rhodes Muriel E. 
Published: March 2008

Summary.Further studies of the aniline‐utilizing soil organism described by Walker & Harris (1969) revealed that it is not a pseudomonad, but a strain of Alcaligenes faecalis Castellani & Chambers 1919. This taxonomic correction is pertinent insofar as Pseudomonas and Alcaligenes may show different pathways of aniline degradation, and the frequency of occurrence of the two genera in the soil may be very different. One hundred and fortyone isolates of fluorescent Pseudomonas spp. from soil and water, failed to grow on aniline as sole carbon source.
Studies on the Antimicrobial Activity of Olive Phenolic Compounds
Authors: Juven B. , Henis Y. 
Published: March 2008

Summary.Treatment of green olives for 2 min with dilute hot alkali before brining increased the release of sugars, B complex vitamins, amino acids and phenolic compounds, and enhanced the establishment of lactic acid bacteria in the brine. Two components of the ethyl acetate extract of green olives, which showed an antibacterial activity, were isolated and identified as the glycoside oleuropein and its phenolic aglycone. The inhibition of Lactobacillus plantarum by the ethyl acetate extract or by oleuropein was augmented by reducing the concentration of organic nitrogenous compounds, increasing the NaCl concentration in the assay medium and decreasing the inoculum size. Besides its activity towards various bacteria, oleuropein inhibited the growth of Geotrichum candidum Link, Rhizopus sp. and Rhizoctonia solani Kühn. On the basis of these findings, an explanation for some problems in the lactic fermentation of green olives is suggested.
Ultrastructure of Spore Coats Produced by Lethal Germination of Spores of Bacillus megaterium 9885
Authors: Holdom R. S. , Williams M. G. , Foster J. W. 
Published: March 2008

Summary.The ultrastructure of free spore coats of Bacillus megaterium 9885 was studied by exploitation of the spontaneous lysis of newly germinated spores in the presence of phosphate and absence of Ca2+, and the subsequent release of coat subunits. The subunits appeared as the middle layer of a sandwich. The primary size of the subunits was c. 20 nm. Negative staining suggested the presence of peripheral charged groups (carboxyl?) surrounding a hexagonal‐shaped subunit containing an acentric electron opaque spot; where subunits had associated into monolayers, the peripheral rims disappeared but the number and position of subunits was located from the acentric spots which remained visible. The newly germinated cell remained attached to the spore coat via a short connecting structure of amorphous material. Ca2+ protected against lysis and also largely prevented coat disruption. Subsequent EDTA treatment did not produce the normal effects of Ca deficiency; instead, thin bridges of elastic material of apparently high tensile strength and remarkably uniform diameter were seen to connect neighbouring spore masses. The significance of these observations is discussed in relation to the known chemical composition of coats of related strains.
The Effect of Cephaloridine and a Cephalosporin Derivative on Mycoplasmas
Authors: Fallon R. J. 
Published: March 2008

Summary.Cephaloridine was found to inhibit many Mycoplasma species at a concentration of 1000 μg/ml of medium. A cephalosporin derivative 7/30 was much more inhibitory than cephaloridine but was less active than dimethyldithiocarbamate, the side chain at position 3 in compound 7/30.
Agglutinin Absorption Reactions with Antigens and Antisera of Smooth Brucellae
Authors: Painter G. M. , Patterson Judy M. , Deyoe B. L. 
Published: March 2008

Summary.The reactions of various Brucella antisera and Brucella antigens were investigated with agglutinin absorption techniques. Agglutinins that sedimented at the slowest rates through sucrose density gradients were absorbed preferentially, but more slowly than were fast sedimenting agglutinins. When antisera were absorbed with small defined quantities of Brucella antigens the identity of the absorbing antigen seldom influenced the results until greater than 50% of the agglutinins were removed. Consequently, the results were mainly dependent upon the antisera and assaying antigen. When antisera were absorbed with small quantities of the homologous antigen and assayed against other antigens, greater serologic differentiation of smooth Brucella was achieved than by testing with Brucella monospecific sera.