bluuebunny/crossref_metadata_2025_split huggingface dataset:
A STUDY OF THE BACTERIA ON THE ROOT SURFACE AND IN THE RHIZOSPHERE SOIL OF CROP PLANTS
Authors: ROUATT J. W. , KATZNELSON H. 
Published: March 2008

SUMMARYThe numbers and kinds of bacteria on the root surface (rhizoplane) of the six crop plants, red clover, flax, oats, maize, barley and wheat, and also in the rhizosphere soil (near the roots) have been compared with the numbers and kinds in root free soil. Bacteria isolated from wheat roots have been classified in genera. All the 6 crops, especially red clover, showed a typical rhizosphere effect, and there were also more bacteria in the rhizoplane than in root free soil. Of the 6 crops, red clover had the most methylene blue reducing bacteria, and flax the highest numbers of glucose fermenting bacteria, in both rhizosphere and rhizoplane. Flax also had very many ammonifying bacteria on its roots. The percentage of strains needing amino acids for optimal growth was highest on the root surfaces, and higher in the rhizosphere than in root free soil, in every case. Wheat roots and the wheat rhizosphere yielded a higher proportion of fast growing, acid tolerant and acid producing bacteria than did root free soil. The taxonomic studies showed that Pseudomonas spp. were predominant on and near wheat roots, but Arthrobacter spp. were predominant in root free soil.
CHARACTERISTICS OF ENGLISH ISOLATES OF ERWINIA AMYLOVORA (BURRILL) WINSLOW ET AL.
Authors: BILLING EVE , BAKER LILY A. E. , CROSSE J. E. , GARRETT CONSTANCE M. E. 
Published: March 2008

SUMMARYThe characteristics of 38 English isolates of Erwinia amylovora were studied independently at East Malling Research Station and at the National Agricultural Advisory Service Laboratories at Wye. The results from both laboratories were similar and indicate considerable physiological homogeneity amongst the isolates. The joint findings are described and compared with those of other authors.
THE EFFECT OF FEEDING COLICINOGENIC ESCHERICHIA COLI ON THE INTESTINAL E. COLI OF EARLY WEANED PIGS
Authors: TADD A. D. , HURST A. 
Published: March 2008

SUMMARYThe Escherichia coli contents of samples of faeces from 24 early weaned pigs were estimated qualitatively and quantitatively in two experiments. At weaning (10 days of age) the E. coli content was about 108/g of faeces. Haemolytic E. coli, often pathogenic serotypes, emerged at 12–20 days of age and then tended to disappear at 30–40 days of age. Colicinogenic E. coli, isolated from the faeces of pigs from another herd, were grown in a 50 1. batch fermenter and added to the diet of the early weaned pigs, from weaning and until the pigs were 40 days old. Within a few days of feeding the colicinogenic E. coli, colicinogenic types formed 20–50% of the coli‐aerogenes flora of the faeces. The feeding and establishment of colicinogenic E. coli did not suppress the haemolytic E. coli and did not affect the incidence of mortality among the pigs.
AN IMPROVED DIAGNOSTIC AND SELECTIVE MEDIUM FOR ISOLATING COAGULASE POSITIVE STAPHYLOCOCCI
Authors: BAIRD‐PARKER A. C. 
Published: March 2008

SummaryThis paper describes the development and use of a selective and diagnostic medium (ETGPA) for isolating coagulase positive staphylococci from food. It combines an improved form of the selective medium of Zebovitz, Evans & Niven (1955) with the ability to clear egg yolk as a diagnostic character. The new medium is noninhibitory but selective to coagulase positive staphylococci from a variety of sources, and its performance is better than that of four recently published media.
SOME ASPECTS OF THE MICROBIOLOGY OF FROZEN PEAS
Authors: WHITE ANNE , WHITE HELEN R. 
Published: March 2008

SummaryThe number of bacteria present in commercially frozen peas was found to be usually between 104 and 106/g. Most of the organisms were of two species, Leuconostoc mesenteroides and Streptococcus lactis. After thawing the leuconostocs multiplied more rapidly than the streptococci and in 48 hr the former constituted almost the entire population.Growth studies of four isolates of each of the above species, both in laboratory media and on blanched peas, showed no difference in growth rates before and after freezing. When some organisms, including potential pathogens, were inoculated on to peas rapid multiplication took place even in the presence of leuconostocs or streptococci.
A QUANTITATIVE AND QUALITATIVE STUDY OF THE LIPOLYTIC ACTIVITY OF SINGLE STRAINS OF SEVEN BACTERIAL SPECIES
Authors: HUGO W. B. , BEVERIDGE E. G. 
Published: March 2008

SummarySingle strains of Serratia marcescens, Staphylococcus aureus, Micrococcus freudenreichii, Pseudomonas hydrophila, Achromobacter fischeri, Bacillus subtilis and Bacillus cereus were examined for their lipolytic activity, qualitatively using different lipolysis detecting media and quantitatively by means of acid production. The substrates investigated were olive oil, tributyrin, ethyl laurate and ethyl butyrate. The effect of temperature and pH on lipolytic activity, as measured by acid production, has also been investigated.
THE FAECAL COLI‐AEROGENES FLORA OF SOILS FROM VARIOUS GEOGRAPHICAL AREAS
Authors: GELDREICH E. E. , HUFF C. B. , BORDNER R. H. , KABLER P. W. , CLARK H. F. 
Published: March 2008

SummaryA study has been made of coli‐aerogenes bacteria isolated from 251 soil samples collected from 26 States and 3 foreign countries. Based on land use, the soils were classified in 8 classes of the undisturbed group and one additional group of soils which were known to have been exposed to various kinds of faecal pollution.Faecal coli‐aerogenes organisms were usually absent, or present in comparatively small numbers only, in undisturbed soils, with most counts being less than 1.8/g. There was a marked increase in the numbers in soils of the polluted group, with a density of between 3,300 and 49,000/g.Intermediate types represented 76% of the 2,348 strains isolated from the undisturbed soil classes, as contrasted with only 17% of 665 polluted soil strains. The IMViC reactions of the predominant type from the undisturbed group were ‐ + ‐ +, and this type represented 48% of the 2,348 strains isolated. The sanitary significance of the ‐ + ‐ + intermediate type as a soil coli‐aerogenes organism, in relation to data on types from faecal samples and certain remote mountain streams, suggests that the strains giving these IMViC reactions, and which are 45° negative, may possibly be considered as a type characteristic in unpolluted soils but relatively infrequent where faecal pollution has occurred.Since soil contains high numbers of organisms, other than coli‐aerogenes bacteria, which frequently produce false positive reactions by the ‘confirmed test’ procedure, the ‘completed test’ method is recommended for the examination of soils for coli‐aerogenes organisms.
THE PHYSIOLOGICAL AND SEROLOGICAL PROPERTIES OF STREPTOCOCCUS BOVIS AND RELATED ORGANISMS ISOLATED FROM CATTLE AND SHEEP
Authors: MEDREK T. F. , BARNES ELLA M. 
Published: March 2008

The physiological and serological properties of 153 strains of Streptococcus bovis isolated from cattle and sheep have been studied. With 12 specific antisera it was possible to type 75 of the isolates. Neither the fermentation of arabinose nor of raffinose was related to type specificity. The only strain fermenting mannitol was serologically distinct from all the other strains, and the type antigen was probably located on the cell wall whereas with the other 11 types it was capsular.The distribution of these types in cattle and sheep has been determined together with their changes in individual cows sampled on three occasions over 18 months.
THE MINERAL NUTRITION OF HANSENULA SPP. OF YEAST IN RELATION TO FAT PRODUCTION
Authors: FAHMY T. K. , HOPTON J. W. , WOODBINE M. 
Published: March 2008

SummaryThe development of cultures of ‘high fat’ and ‘low fat’ species of Hansenula under different nutritional regimes in shaken culture has been examined. The cultures were sampled at frequent intervals throughout growth, and determinations made of cell number and cell mass, uptake of nitrogen and glucose and synthesis of fat and polysaccharide.In all media there was an initial phase of rapid multiplication associated with nitrogen uptake, but appreciable increase in yeast mass occurred after the glucose had been exhausted and most of the accretion of fat and polysaccharide occurred during this phase of growth. In a nitrogen deficient medium the production of fat and polysaccharide was accentuated and, whereas the cell count of ‘low fat’ species increased during the second assimilatory phase, that of ‘high fat’ species did not. The behaviour of yeasts in a phosphorus deficient medium simulated that in a nitrogen deficient medium, but behaviour in a medium containing a low concentration of sulphur differed little from that in a complete medium.
Clostridium botulinum in Sweden and the Adjacent Waters
Authors: Johannsen A. 
Published: March 2008

SummaryCl. botulinum type E is ubiquitous in Sweden and the adjacent seas. It is of terrestrial origin and is the dominant type in the Baltic's catchment area. The Baltic is thus a reservoir for type E organisms, which spread to neighbouring waters. The high frequency of type E organisms in the peel of stored potatoes may be regarded as one of the most definite indications of the terrestrial origin of this clostridium.
The Relative Efficacy of Six Selective Media in Isolating Coagulase Positive Staphylococci from Meats
Authors: Jay J. M. 
Published: March 2008

SummaryCoagulase positive staphylococci were found in 30% of 236 meats when egg yolk agar was used, in 22% of 45 meats when mannitol‐sorbic acid broth was used, in 16% of 70 meats when mannitol‐salt agar was used, in 21% of 146 meats when tellurite‐glycine agar was used, in 8% of 75 meats when polymyxin agar was used and in 7% of 54 meats when Vogel and Johnson agar was used. Of a total of 855 suspect colonies tested from the five solid media, 245 (29%) were coagulase positive. All of the media showed higher percentages of recovery from meats that contained relatively large numbers of staphylococci in proportion to the total number of cocci. The simultaneous use of egg yolk agar and mannitol‐sorbic acid medium gave the best results.
A Rapid, Unequivocal Method for Detecting Glutamic Acid Decarboxylase in Primary Plate Cultures of Enterobacteriaceae
Authors: Stewart D. J. 
Published: March 2008

SummaryIn a rapid technique for detecting L‐glutamic acid decarboxylase activity in lactose fermenting colonies growing on purple MacConkey's agar the colonies, after exposure to toluene vapour for 30 min, are removed from the agar surface with small filter paper discs and allowed to act on a buffered substrate containing 1% of L‐glutamic acid for 1 h. The amino acids are extracted from the disc with a small drop of water and separated by paper chromatography in 1–3 h.A considerable increase in decarboxylase activity was produced by exposing the cells to toluene vapour. Pyridoxal‐5‐phosphate in the substrate also stimulated activity to a lesser degree.
Sources of the Lactic Acid Bacteria Occurring in Silage
Authors: Stirling Anna C. , Whittenbury R. 
Published: March 2008

SummaryLactobacilli, pediococci and leuconostocs were found to be scarce on living undamaged plant tissue. They were not found by direct plating of intact portions of the inflorescence or seed of any plant examined, but they were detected on foliage damaged by insects, on sheaths at the base of grasses and on withered blades of grass. The numbers of lactic acid bacteria on plant material increased during the harvesting and ensiling operations. Many organisms were recovered from the mechanical equipment and the hand implements used during harvesting of the crop.
Studies on Jute Retting Bacteria
Authors: Ahmad M. 
Published: March 2008

Summary: A total of 1,438 colonies of aerobic and anaerobic bacteria has been isolated from samples of retted jute stems collected from 12 districts of East Pakistan. Of these, 169 isolates have been purified and characterized. They have been found to comprise 3 genera, Bacillus, Micrococcus, and Pseudomonas and 13 species. Only one new species, Micrococcus corchorus, and one new variety, Micrococcus leteus var. liquefaciens, are reported; these will be described elsewhere.Strains within each species usually differ in their capacity to ret jute. Active retting strains have been found to lose their retting activity, and it has been concluded that this loss may follow either from loss of adaptive enzymes or from mutations.Among the aerobes and facultative anaerobes, B. subtilis has been found to be the most common and B. macerans, B. polymyxa, Micrococcus corchorus and Pseudomonas aeruginosa the most active retting agents in East Pakistan. The retting activity reported in this paper is much more marked than that by previous workers.A detailed description of the process of jute retting is given.
Factors Affecting the Growth and Fat Formation of Rhodotorula gracilis
Authors: Allen L. A. , Barnard N. H. , Fleming Muriel , Hollis B. 
Published: March 2008

Summary: The vitamin requirements of Rhodotorula gracilis are satisfied by inclusion in the growth medium of pantothenic acid and thiamine. For maximum growth in the particular medium and with the size of inoculum used in our experiments a concentration of about 10 μg of pantothenate/1 was sufficient but for rapid early growth a higher concentration was beneficial.Pantothenic acid can be replaced by β‐alanine but maximum growth response then occurs only in the presence of asparagine. Either ammonium sulphate or urea provides a suitable source of nitrogen for growth of the organism.Shake flask experiments with a synthetic medium showed that a solution containing only glucose and phosphate was adequate for fattening, that wide limits in pH value (e.g. 4–8) were permissible and that the rate and efficiency of fat production were not affected by large differences in the concentration of sugar.Provided sugar was still present in the medium a progressive decrease in the percentage of protein was accompanied by a corresponding increase in the percentage of fat in the yeast. When aeration was prolonged beyond the point at which all the sugar was exhausted, this trend was reversed.The fat produced during fattening had a lower iodine value than that produced during normal growth. Only a small proportion of the fat in Rh. gracilis is in the free condition and extractable by direct treatment with a simple solvent. Preliminary hydrolysis with hot HCl is necessary for quantitative release of the fat.Refinery cane molasses provides a suitable source of sugar both for growth and for fattening of Rh. gracilis. Growth in a fermentor with incremental feeding, under conditions of high aeration and rapid stirring, gave a yield of dry yeast equivalent to 52–54% of the sugar consumed; the doubling time during the logarithmic growth phase was 3 h.Aeration of Rh. gracilis in a phosphate‐molasses medium resulted in a rapid consumption of sugar during the whole period of aeration. This was accompanied by an increase in the weight of yeast, accounted for by an increase in all constituents—fat, carbohydrate, mineral matter and a small amount of protein formed from the residual nitrogen carried over from the growth medium. Since much more fat than protein was produced the percentage of fat in the yeast rose and the percentage of protein fell. The proportion of carbohydrate in the cell was subject to some fluctuation. Under certain conditions it appears that the reserves of carbohydrate may be drawn upon to provide energy for fat formation, resulting in an actual destruction of cellular carbohydrate.The proportion of sugar converted to fat rose to a maximum between c. 14–23 h and then rapidly declined. For a short period a fat coefficient of over 40% was attained in one experiment. Thereafter conversion was relatively inefficient, a small quantity of fat being produced from the consumption of a large quantity of sugar.
A Serological Approach to the Genus Pseudomonas
Authors: Hobbs G. , Cann D. C. , Gowland G. , Byers Hilary D. 
Published: March 2008

Summary: Serological methods are described by which organisms of the genus Pseudomonas and related genera can be compared. More specific relationships are demonstrated by agglutination techniques or agar diffusion with trichloroacetic acid extracts; less specific relationships are shown by agar diffusion with disintegrated cell preparations. Up to three strain specific antigens may be found and at least six antigens are widely distributed amongst strains of the genera Pseudomonas, Achromobacter, Vibrio and Aeromonas.The results obtained so far indicate little or no agreement with any accepted taxo‐nomic divisions. Evidence is presented which suggests that most of the antigens detectable by agar diffusion techniques are polysaccharide in nature rather than protein.
The Effect of Freezing on the Radiation Sensitivity of Vegetative Bacteria
Authors: Matsuyama A. , Thornley Margaret J. , Ingram M. 
Published: March 2008

Summary: Five strains of bacteria were irradiated, suspended in heart infusion broth or in phosphate buffer, in aerated or anoxic conditions, at temperatures of 10–13° or ‐79°. Survivors under the different conditions were enumerated by plate counts on heart infusion agar.Exponential survivor‐dose curves were obtained with a Pseudomonas strain and with Escherichia coli B/r when irradiated at room temperature with aeration, whereas an Alcaligenes strain and 2 strains of Streptococcus faecium gave sigmoid curves. The decreased radiosensitivity in the frozen state was measured by comparing the D10 values for exponential curves, or for the exponential portion of sigmoid curves, with that observed for irradiation at room temperature with aeration. This ‘D10 ratio’ svaried between 2°5 and 8·5. For the Alcaligenes strain it was about 4, whether the frozen irradiation took place in the presence or absence of oxygen. With the Pseudomonas irradiated in the frozen state in the absence of oxygen the ‘D10 ratio’ was usually about 1·5 times higher than when oxygen was present. The highest ratio (8·5) was obtained for anoxic irradiation of the Pseudomonas strain.In general, the shapes of survival curves for frozen irradiation differed from those obtained at room temperature. The sigmoid curves for the Alcaligenes strain irradiated under aerobic conditions when frozen showed a marked decrease in extrapolation numbers. E. coli B/r when frozen in heart infusion broth gave a double exponential curve with a shallow slope initially, followed by a steeper slope. The most radiation resistant strain, Strep. faecium R53, gave sigmoid curves with a D10 value of 300 Krads when frozen, and was then of similar resistance to Clostridium botulinum spores.
Studies on Coli‐aerogenes and Other Gram‐negative Intestinal Bacteria in Various Animals and Birds
Authors: Mushin Rose , Ashburner Frances M. 
Published: March 2008

Summary. Some faecal material from native animals and birds (especially) showed either no coli‐aerogenes bacteria or contained types other than Escherichia coli I.Amongst coli‐aerogenes isolates, E. coli I was frequent but the high percentage of other biotypes indicated that the animal host may serve as a pool of intermediate and irregular strains. Paracolons and Proteus spp. were abundant, and Salmonella spp. were isolated from dogs and native animals possibly in contact with man.Animals were only occasionally carriers of enteropathogenic E. coli serotypes and seldom of types locally important in the etiology of infantile diarrhoea, such as E. coli O26:B6 and O55:B5. In this series O86 serotypes other than the diarrhoeal strain isolated from babies were found. The results of the study indicated some degree of host specificity. In the group of 20 O serotypes (referred to as specific E. coli), O8 was most commonly listed. Most strains were sensitive to chemotherapeutic agents but resistance of some strains especially to sulphonamide was recorded.The implication of the presence in the animal gut of coli‐aerogenes bacteria other than E. coli type I is discussed in relation to bacterial standards for drinking water.
The Occurrence of Clostridia on Bacon Slaughter Lines
Authors: Baltzer J. , Wilson D. C. 
Published: March 2008

Safety in the production of canned meat products depends on the numbers of heat resistant clostridia in the product before processing, as the effect of heat processing is limited. For this reason, the numbers of clostridia in the raw materials are of great importance, and any method which may reduce these numbers is of value.This investigation has shown that clostridia are present on the rind side of pig carcases at various stages during slaughter operations, the numbers depending on the bacteriological state of the slaughtering equipment. In addition, frozen sections have indicated the presence of clostridia in the deeper layers of the skin. Washing the carcases with hot water besides lowering the aerobic count also reduces the numbers of clostridia.
The Identification of Wild Yeast Colonies on Lysine Agar
Authors: Fowell R. R. 
Published: March 2008

The most common wild yeasts infecting pressed baker's yeast in Great Britain are Candida tropicalis, C. krusei, C. mycoderma, Trichosporon cutaneum, Torulopsis candida and Rhodotorula mucilaginosa. Wild yeasts are readily detected and quantitatively estimated by plating infected baker's yeast on lysine agar, which permits of only limited growth of baker's yeast.Morphology of wild yeast colonies on lysine agar is affected by duration of incubation, location in the agar plate, and sometimes by temperature of incubation, density of infection and numbers of baker's yeast cells present. It is therefore possible to identify each species by at least one characteristic type of colony produced under specified conditions. Ability to grow at 30° and 37° serves to distinguish further between certain species.
The Dissolved Oxygen and Respiration Rates in Pellicle and Submerged Cultures of Corynebacterium diphtheriae
Authors: Brighton W. D. 
Published: March 2008

Summary. The concentration of dissolved oxygen in submerged and static cultures of Corynebacterium diphtheriae was measured with a cathode ray polarograph. In a pellicle culture of the type frequently used for production of diphtheria toxin the concentration of dissolved oxygen in the medium below the pellicle fell sharply after the third or fourth day, and growth then proceeded in a medium which contained only minimal amounts of dissolved oxygen, in spite of the fact that only a cotton wool plug separated the atmosphere above the medium from the outside air.The measurement of dissolved oxygen in submerged cultures was applied to the determination of respiration rates in growing cultures. The respiration rate for the test organisms varied at different stages in the period of a submerged batch culture. The rate was greatest at the start of the logarithmic phase, and thereafter declined until a steady state was reached.