bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE RATES OF GROWTH OF SOME THERMODURIC BACTERIA IN PURE CULTURE AND THEIR EFFECTS ON TESTS FOR THE KEEPING QUALITY OF MILK
Authors: WILLIAMS D. J. 
Published: March 2008

SUMMARY: The growth rates of eleven representative thermoduric bacteria, comprising 3 aerobic spore formers, 3 streptococci, 1 Corynebacterium lacticum and 4 micrococci, have been determined in glucose broth and sterile pasteurized milk at 37·5°, 26° and 15°. The spore formers and streptococci were generally not affected by the presence of inhibitory factors in pasteurized milk. When multiplication of micrococci and C. lacticum occurred in milk this was only after a lag period. One micrococcus showed an unusual series of growth phases in glucose broth at 37·5°, possibly due to the appearance of mutants or to adaptation of the organism to growth at that temperature. This was not observed in pasteurized milk. C. lacticum died off when incubated in glucose broth at 37·5°.None of the keeping quality tests was more effective than any other in detecting these organisms in milk. The micrococci and C. lacticum had little effect on the keeping quality of pasteurized milk within the period of ‘commercial life’. Some of the spore formers and streptococci showed marked differences in the end‐points with the clot‐on‐boiling and the alcohol precipitation tests.
THERMODURIC ORGANISMS IN MILK. PART V. A SIMPLIFIED TESTING TECHNIQUE
Authors: EGDELL J. W. , THOMAS S. B. , CUTHBERT W. A. , JONES G. E. , HOSKING ZENA D. 
Published: March 2008

SUMMARY: Thermoduric colony counts at 30° of laboratory pasteurized milk determined by the roll tube or agar strip methods were lower than those obtained by the standard Petri plate method. The differences in colony count were not of such magnitude, however, as to be likely to result in many errors in grading if a thermoduric bacterial content of greater than 104/ml is accepted as an index of unsatisfactory cleansing of dairy equipment.The three methods examined were simpler and more economical than the Petri plate technique, but the agar strip method, as described, using the standard loop, was the simplest and gave a sufficiently reliable estimate of the thermoduric colony count for advisory purposes.
THE OCCURRENCE OF COLI‐AEROGENES ORGANISMS ON PLANTS
Authors: FRASER MARGARET H. , REID WINIFRED B. , MALCOLM J. F. 
Published: March 2008

SUMMARY: Coli‐aerogenes bacteria were seldom found on the foliage of a wide variety of garden plants, trees and shrubs, and field plants, including pasture, except where there was a possibility of contamination by insects, animals or dust. They were present in only a few instances on the flowering heads of hay plants (wind pollinated) but on almost all the flowers of garden plants (insect pollinated). Although cereal crops are wind pollinated, coli‐aerogenes organisms were found on about one‐third of the grains examined. The question of their origin on grain is discussed.In a series of paired samples of soil and of the foliage of the covering vegetation, coli‐aerogenes organisms were present in most of the soil samples, but were absent from the foliage except where animal contamination was possible, as in the case of grazed pasture.With foliage samples unlikely to have been contaminated by animals, most of the coli‐aerogenes organisms isolated were A. cloacae, but with grazed pasture E. coli predominated, indicating contamination by grazing animals.The coli‐aerogenes floras of garden flowers and cereal grains corresponded closely, consisting in each case largely of A. cloacae.
THE DIFFERENTIATION OF BACTERIAL SPECIES BY PAPER CHROMATOGRAPHY. V. PRELIMINARY EXAMINATION OF THE MICROCOCCI
Authors: GREGORY MARGARET , MABBITT L. A. 
Published: March 2008

SUMMARY: Chromatograms of unhydrolyzed extracts of the type strains of the Cowan groups of the micrococci and of other representatives of these groups have shown that the resulting pattern of ninhydrin‐positive spots is useful taxonomically.The grouping based on the chromatograms agreed well with the Gibson grouping, but indicated that Cowans group III contained some dissimilar organisms.
SOME BIOCHEMICAL CHARACTERISTICS OF FRESHLY ISOLATED STRAINS OF THE GENUS SERRATIA
Authors: THOMAS S. B. , LEWIS ELIZABETH 
Published: March 2008

SUMMARY: Many of 110 strains of Serratia, isolated from soil, water, milk and dairy equipment, were biochemically closely related to the coli‐aerogenes bacteria. Acid and gas was formed from glucose in 14 days at 30° by 53% and from lactose and MacConkey's broth by about 40%. All except one strain gave——++ IMViC reactions.An inverse relationship was observed between depth of pigmentation and carbohydrate fermentation. Complete loss of pigment in mutant strains was not uncommon, and was associated with loss of proteolytic properties and increase of saccharolytic activity.The majority of the strains had psychrophilic characteristics: 75% grew at 3–5°. Most strains showed moderate growth at 37°, but only 7 formed red pigment at that temperature.All strains resembled Serratia marcescens in morphology, containing minute coccoid rods smaller than those of coli‐aerogenes bacteria.
CHANGES IN THE SKIN FLORA OF COD AFTER WASHING AND ICING
Authors: GEORGALA D. L. 
Published: March 2008

SUMMARY: Bacterial counts done on the skin of North Sea cod show that while washing with running sea water greatly reduced the numbers on newly caught fish, contact with ice from a trawler's ice bunker resulted in an immediate large increase on the washed fish.Washing did not materially alter the percentage representation of the various genera present, but icing with trawler bunker ice could cause major alterations and often added types of bacteria similar to those present on newly caught fish, indicating contamination of the ice on board the trawler.
THE ASSESSMENT OF RELATIVE BACTERICIDAL ACTIVITY AMONG CERTAIN PHENOLS BY A PHYSICAL METHOD
Authors: MAURICE P. 
Published: March 2008

SUMMARY: The addition of phenol, various alkyl phenols, or CTAB to a suspension of E. coli in distilled water caused the optical density to increase, the change being more marked as the concentration of a given compound was raised. Families of curves of similar shape were obtained with all the compounds when optical density was plotted against time for different concentrations, and figures expressing the activity relative to that of 1·2% phenol were obtained by dividing the concentration which produced the same curve as that concentration of phenol, into 1·2. These figures were very similar to those obtained for the bactericidal effects of the compounds relative to 1·2% phenol, using an ‘end‐point’ method.The presence of the chlorides of mono‐ and divalent metals at 10−4 M, or of the sulphates of trivalent metals at 10−5 M, did not affect the turbidity reaction, but higher concentrations of monovalent metal salts, e.g. 2 × 10−2 M phosphate buffer (potassium) at pH 6·7, markedly retarded the change due to phenol. That concentration of the buffer also greatly reduced the bactericidal activity of 1·2% phenol. Much of the turbidity increase, however, occurred after all the cells of the suspensions had been killed, with phenol concentrations over 1·0%.
THE PRESERVATION OF PSEUDOMONAS UNDER MINERAL OIL
Authors: RHODES MURIEL E. 
Published: March 2008

SUMMARYThe use of mineral oil for the preservation of species of Pseudomonas is described. Eighty‐three out of 91 (91·2%) Pseudomonas isolates remained viable for at least 66 months; 156 out of 168 (92·8%) isolates were still living after at least 46 months, and only 12 out of 170 (2·3%) isolates were non‐viable after three years. An explanation is offered for variation in ability to grow and produce acid in chemically defined media containing galactose or sucrose. The ability to hydrolyze tributyrin and to reduce nitrate was stable over 66 months, regardless of whether the stock cultures were maintained under mineral oil or in yeast‐extract peptone broth. However, the ability to digest milk or gelatin was frequently impaired or lost when cultures were maintained in peptone broth, although the mineral oil‐preserved stock cultures remained stable in this respect. Over a nineteen month period six diagnostic biochemical characters of the oil‐covered stock cultures remained stable within the limits of the experimental methods used. Data from the literature and information from other workers reveal that more complex methods of preserving pseudomonads are not particularly advantageous in regard either to viability or stability. The mechanism of the survival of bacteria under mineral oil is discussed. The taxonomic significance of the loss of proteolytic activity by the ‘bench‐broth’ cultures of Pseudomonas spp. is illustrated by a single example.
BACTERIOLOGICAL STUDIES OF IMMERSION CLEANING OF MILKING EQUIPMENT ON COMMERCIAL FARMS
Authors: EGDELL J. W. , LOMAX KATHLEEN L. , ADAMS R. P. , AITKEN MARGARET J. 
Published: March 2008

SUMMARY: A study has been made of the immersion cleaning technique as applied on commercial farms. In an initial survey bacteriological results for rinses and swabs of the milking equipment were satisfactory on most farms, but on one farm the results were very disappointing. Further investigations at this farm showed that the poor results were caused partly by sporing bacteria which survived the caustic soda treatment, presumably in the spore state, and partly by non‐sporing organisms, chiefly chromobacteria and micrococci.These non‐sporing organisms are found in abundance on the surface of dirty wash troughs, and under certain conditions re‐contamination of the milking equipment can occur during the rinsing operation. Suggested modifications to the original immersion cleaning technique include the use of hot water for the before‐milking hypochlorite rinse, brushing the equipment in the after‐milking rinse to remove extraneous dirt, regular cleansing of the wash trough and the monthly cleansing of the basket and bin.
A STUDY OF SOIL BACTERIA DISSOLVING CERTAIN MINERAL PHOSPHATE FERTILIZERS AND RELATED COMPOUNDS
Authors: LOUW H. A. , WEBLEY D. M. 
Published: March 2008

SUMMARY: Over a hundred isolates which produced haloes around their colonies on dilution plates containing calcium carbonate or dicalcium phosphate have been obtained in pure culture from the root region of the oat plant. Of these, more than 50% were pleomorphic, and this group had the highest proportion of isolates which could produce clear zones on agar media containing either calcium carbonate, dicalcium phosphate, tricalcium phosphate, freshly precipitated hydroxyapatite or basic slag. None of the isolates showed dissolving ability on agar media containing gafsa rock phosphate, variscite, strengite or taranakite. However, when an analytical method was used, 82% of the isolates tested proved able to release phosphate from gafsa rock phosphate, though to a much lesser extent than from dicalcium phosphate. None of the isolates tested by this method released phosphate from variscite, strengite or taranakite.The nature of the organic acids produced from glucose by 26 of the isolates was also investigated. The majority produced mainly lactic acid, but a few also gave an acid with chromatographic properties similar to those of 2‐keto‐gluconic acid.
MYCOLOGICAL SYNTHESIS OF FAT FROM WHEY. I. PRELIMINARY STUDIES WITH STATIONARY CULTURES
Authors: WIX P. , WOODBINE M. 
Published: March 2008

SUMMARY: Forty mould species, 30 of which were from the genera Aspergillus, Penicillium, Fusarium and Mucor, were examined for their ability to utilize the lactose in whey and to produce fat in the mycelium in stationary cultures.In terms of lactose consumed and weight of mycelial felt produced the most promising species were A. ustus, P. frequentans, P. oxalicum and P. notatum. The first three of these warrant further study as fat producers.
A STUDY OF A GRAM‐POSITIVE COCCUS RESPONSIBLE FOR ROPINESS AND VISCOSITY IN MALT WORT
Authors: HOPTON J. W. , HALL A. N. 
Published: March 2008

SUMMARY: A Gram‐positive coccus with the properties typical of pediococci produced a ropy, viscous growth in malt wort. Nutritional studies in the media of Dunn et al. (1947) showed pantothenic acid to be required by the organism but growth occurred in the complete medium only when a trace of malt wort was present. Seven other vitamins tested were not necessary for growth.In a medium consisting of mineral salts, glucose and alcoholic extracts of peptone and yeast autolysate the organism grew well and the viscosity of the medium increased. Higher viscosities were attained when the buffering capacity of the medium was increased either by raising the concentrations of the alcoholic extracts or by adding sodium acetate. The material responsible for the viscosity was produced in small amounts only and appeared to be a mucopolysaccharide. The only sugar obtained on hydrolysis of this material was glucose.Fructose, maltose, sucrose and raffinose were all fermented by the organism but only in media containing maltose was the increase in viscosity comparable with that attained in a glucose‐containing medium.
A STUDY OF THE BACTERIA ASSOCIATED WITH THE ROOTS OF SUBTERRANEAN CLOVER AND WIMMERA RYE‐GRASS
Authors: SPERBER JOAN I. , ROVIRA A. D. 
Published: March 2008

SUMMARY: A study of the bacteria from the surfaces of roots of subterranean clover (T. subterraneum L.) and Wimmera rye‐grass (L. rigidum Gaud.) revealed that 21 genera were represented among the isolates from clover and 16 genera among those from rye‐grass. Bacteria showing branched forms predominated and accounted for 63% of the 151 clover isolates and 78% of the 167 grass isolates. Most of these were identified as Arthrobacter, but from clover a significant proportion were Nocardia‐like types. Members of the genera Mycoplana, Micromonospora, Mycobacterium, and Mycococcus were also identified among the branching forms.Although the soil had been inoculated with effective rhizobia and the clover plants were effectively nodulated only one of the 318 isolates was capable of nodulating subterranean clover. The majority of the isolates were chromogenic and Gram‐negative, produced acid from glucose and ammonia from peptone, were catalase‐positive and grew best aerobically. Approximately half the isolates liquefied gelatin and produced hydrogen sulphide from peptone.
EXPERIMENTS ON THE ACCURACY OF SURFACE DROP BACTERIAL COUNTS
Authors: BADGER E. H. M. , PANKHURST EILEEN S. 
Published: March 2008

SUMMARY: A statistical experiment has shown that no significant proportion of the errors of determination of bacterial populations by the surface drop method could be attributed to the dropping technique employed. With both pure and mixed cultures the numbers of colonies/drop followed a Poisson distribution very closely.It is suggested that in order to determine bacterial populations at a consistent level of accuracy a constant number of colonies should be counted rather than a constant number of drops. Whenever it is justified, the confidence limits for the results of counts should be quoted.
THE EFFECT OF CHLORTETRACYCLINE ON EVISCERATED CHILLED CHICKENS COMMERCIALLY PROCESSED IN GREAT BRITAIN
Authors: WALKER ELIZABETH A. , TAYLOR J. H. , DAVIS J. G. 
Published: March 2008

SUMMARYThirty broiler chickens of known weight and history were processed simultaneously under normal conditions in each of three poultry packing stations, visually assessed to be operating at ‘ideal’, ‘good’, and ‘poor’levels of hygiene. The eviscerated carcases were bisected, cooled to 3° in chilled air, and distributed between three treatment groups which were dipped for 30 min in chilled water containing 0, 10 and 20 p/m of chlortetracycline respectively. During storage at 3° for 3 weeks, microbiological and sensory examinations were undertaken. At all levels of hygiene, the application of the antibiotic significantly delayed the onset of spoilage; the differences between the effects of 10 and 20 p/m were small and generally insignificant. Bacterial counts of 106/cm2 of skin were obtained from the controls on the 7th day of storage whereas similar counts on the treated groups were not reached until the 14th day. ‘Off’odours developed in the control groups between the 5th and 7th days and in the treated groups between the 10th and 14th days. The nature of the spoilage flora acquired during processing appeared to be associated with the duration of storage.
THE EFFECT OF CHLORTETRACYCLINE ON EVISCERATED FROZEN CHICKENS COMMERCIALLY PROCESSED IN GREAT BRITAIN
Authors: WALKER ELIZABETH A. , TAYLOR J. H. 
Published: March 2008

SUMMARYTwenty broiler chickens of known history were processed, bisected, randomly distributed between two groups and then cooled for 2 hr in water and ice. One group was treated with 10 p/m of chlortetracycline. After wrapping, the carcases were blast frozen and stored, first at —15° for 5 months, and then at 3°. During the latter period sensory examinations were done. Treatment with chlortetracycline delayed the appearance of visible microbial growth from a mean of 6·2 days in the controls to 7·8 days, and the onset of ‘off’ odours was also delayed, from a mean of 6·1 days in the controls to 8·5 days. It appeared that poultry meat which had been frozen and thawed was more highly perishable than fresh chilled poultry meat.
THE RAPID TENTATIVE RECOGNITION OF PSYCHRO‐TROPHIC TYPES AMONG ENTEROBACTERIACEAE ISOLATED FROM FOODS
Authors: MOSSEL D. A. A. , ZWART H. 
Published: March 2008

SUMMARYEnterobacteriaceae which can grow at the temperatures prevailing in refrigerated food stores (‘psychrotrophic’Enterobacteriaceae) can be distinguished from strains which cannot develop below 10° because the latter generally grow quickly on nutrient agar at 43°0±1° whereas the former do not. By this test inadequately refrigerated foods can be differentiated from those kept properly refrigerated.
DEVELOPMENTS IN APPARATUS FOR THE CULTURE OF MICRO‐ORGANISMS: DESIGN FEATURES OF A LABORATORY TWO STAGE CONTINUOUS FLOW CULTURE APPARATUS
Authors: CALLOW D. S. , PIRT S. J. 
Published: March 2008

SUMMARYA two stage continuous flow apparatus with a first stage working volume of 2–3 1. and a second stage working volume of 6–14 1. is described.Each stage has separate controls over the environmental factors; temperature, pH value and nutrient supply; and over foaming.In the first stage the dilution rate is altered by changing the flow rate; in the second stage the dilution rate is altered by changing the working volume.The apparatus has proved suitable for the continuous culture of a filamentous mould, which is more exacting from the engineering standpoint than culture of bacteria.
A NOTE ON THE SYSTEMATIC POSITION OF VIBRIO FETUS
Authors: PARK R. W. A. 
Published: March 2008

SUMMARYThe morphology of Vibrio fetus, and of some nonpathogenic vibrios isolated from cattle, has been compared with that of 5 type cultures of Vibrio spp., including V. cholerae, and the systematic position of these bovine vibrios reviewed. Morphological differences between V. fetus and the nonpathogenic bovine vibrios have been observed. These may be of assistance in their identification.
A STUDY OF ANTIGENS OF THE AEROBIC SPOREFORMING BACTERIA
Authors: NORRIS J. R. , WOLF J. 
Published: March 2008

SUMMARYSpore, vegetative O and vegetative H agglutinogens were demonstrated as separate entities in Bacillus species. Spore precipitinogens were distinct from those of the vegetative stage, the latter being associated with the H antigen.Injection of viable spores into rabbits resulted in the formation of antibodies for the vegetative phase as well as spore antibodies, while injection of autoclaved spores gave rise to spore antibodies only.Spore agglutinogens varied in their strain specificity, B. cereus and B. megaterium especially showing much subspecies specificity, but the spore precipitinogens showed a high degree of species specificity and could be of considerable taxonomic value. The multiplicity of spore precipitinogens in certain species was demonstrated and inter‐species cross reactions were studied.
A NOTE ON THE PRESENCE OF ANTIBACTERIAL SUBSTANCES IN TOBACCO PLANTS
Authors: DADD A. H. 
Published: March 2008

SUMMARYThe juice pressed from twelve varieties of tobacco, and materials extracted with ether from these plants, frequently displayed antibacterial activity against several species of bacteria. Some varietal difference in activity towards Ps. tabaci was observed, and there is a suggestion of some correlation between this and resistance to ‘Wildfire’.
BACTERIOLOGICAL CHANGES IN SILAGE AS AFFECTED BY LACERATION OF THE FRESH GRASS
Authors: GIBSON T. , STIRLING ANNA C. , KEDDIE R. M. , ROSENBERGER R. F. 
Published: March 2008

SUMMARYGrass, after (a) mincing, (b) chopping (to 1–3 cm), and (c) neither treatment, was ensiled at 30° in the laboratory. The growth of Gram‐negative organisms and of each of the main groups of lactic acid bacteria was fastest in the minced material and slowest in the untreated. Mincing had the special effect of permitting the multiplication of lactic acid bacteria when other silage organisms were losing viability. The pH value decreased much more rapidly and to lower levels in minced silage than it did in silage of untreated grass. Variations in response to the treatments were associated with differences in the bacterial populations on the fresh grass and with properties of the grass. Silage made in larger quantities in concrete silos from untreated or lacerated grass of high sugar content had a bacterial population dominated by lactobacilli and was of low pH irrespective of the treatment applied. Silage made at 30° in the laboratory from the same herbage showed that the effects of laceration were considerable and similar to those of mincing.
THE PRESERVATION OF MARINE BACTERIA
Authors: FLOODGATE G. D. , HAYES P. R. 
Published: March 2008

SUMMARYForty‐five marine bacteria and five nonmarine strains, representing 10 genera, were preserved by freeze drying, by storage in glycerol‐nutrient broth at —29° and under paraffin oil at 1°. Checks on viability and viable counts were made over a two year storage period. At the end of this time 100% of the strains had been preserved by freeze drying, 86% by storage in glycerol‐nutrient broth at low temperature and 72% under paraffin oil. The greatest loss of viability occurred among the vibrios and spirilla whichever of the three methods was used, but coryneforms, achromobacters and micrococci were successfully preserved by all these methods.
A SELECTIVE MEDIUM FOR THE ISOLATION AND ENUMERATION OF COAGULASE POSITIVE STAPHYLOCOCCI FROM FOODS
Authors: HOPTON J. 
Published: March 2008

SUMMARYA medium is described for the isolation and enumeration of coagulase positive staphylococci from food products. It was based on the observation that coagulase positive staphylococci produced a zone of clearing in egg yolk emulsion suspended in an agar medium. In conjunction with a modified coagulase test most coagulase positive staphylococci can be confirmed within 24 hr. The majority of coagulase negative staphylococci produced no clearing; when present it was frequently accompanied by a precipitation zone within the clearing area. Sodium azide was used as a selective agent.