bluuebunny/crossref_metadata_2025 huggingface dataset:
The Behaviour of a Food Poisoning Strain of Clostridium welchii in Beef
Authors: Barnes Ella M. , Despaul J. E. , Ingram M.
Published: March 2008

Summary: An inoculum of 105 spores of Clostridium welchii F2985/50 in meat survived steaming at 100° for 5 h, the number being reduced sevenfold for every hour of steaming. They also survived for at least 6 months in frozen meat stored at ‐5° and ‐20°, whereas vegetative cells died more rapidly at ‐5° than at ‐20°. In beef stored for 13 days at 1°, 5°, 10° and 15° there was no multiplication but a slow destruction of vegetative cells, but there was little change in the spore count. Slow multiplication occurred at 20° but at 25° and 37° growth was rapid. Only about 3% of the spores germinated without prior heat shock, so the majority failed to germinate in raw meat stored at any temperature, but did so once the meat had been heated. In meat which had been heated and allowed to cool almost all of the spores had lost their heat resistance.

It was found that the minimal growth temperature was related to pH and medium, so that meat with a pH higher than that used in these experiments (pH 5°7–5°8) would probably have a lower minimal growth temperature for these organisms and would thus be more susceptible to spoilage.
The Antibacterial Activities of Some Esters of Chloramphenicol
Authors: Ellis G. P. , Epstein C. , King J.
Published: March 2008

Summary: The search for a tasteless derivative of chloramphenicol for inhalation as a fine powder has led to the preparation of several new esters. Their in vitro inhibitory activities against Sarcina lutea both in the presence and in the absence of an enzyme system is described.
A Note on the Survival of some Bacteria in Different Diluents
Authors: King W. L. , Hurst A.
Published: March 2008

The best diluent for four bacterial species was 0·1% (w/v) peptone solution. Tap water containing 0·1% (w/v) sodium thiosulphate was less satisfactory but tap water, tap water treated with charcoal, quarter‐strength Ringer's solution, 0·85% (w/v) sodium chloride solution and glass distilled water were all bactericidal to one or more of the test species.
Some Factors Affecting the Lisboa Surface Film Test for Detergent‐Sterilizers
Authors: Mitchell T. G.
Published: March 2008

Summary: In experiments with a surface film test it was found that variation of certain test conditions affected the relative activity of two detergent‐sterilizer formulations. It was also found that to achieve a high degree of reproducibility in the residual count on a treated surface from one occasion to another, it is necessary to control closely the numbers of bacteria present in the dried milk film.
A Selective Method for Cultivating Heat Resistant Moulds, particularly those of the Genus Byssochlamys, and their Presence in Dutch Soil
Authors: Put Henriëtte M. C.
Published: March 2008

Summary: Heat resistant moulds of the genera Byssochlamys, Aspergillus, Penicillium and Paecilomyces can be cultivated selectively in the presence of Bacillus spp. when at least 10 p/m of chloramphenicol or chlortetracycline is added to the growth medium. The inhibitory agents sulphafurazole, penicillin, streptomycin, oxytetracycline and furazolidone, do not give completely selective and optimal growth of these moulds. Selective cultivation of heat resistant moulds from 200 samples of Dutch soil showed that Byssochlamys nivea occurs more frequently than was expected, whereas Byss. fulva occurs by way of exception. Other heat resistant moulds observed in soil are, in order of frequency, species of the genera Aspergillus, Paecilomyces and Penicillium.
Fluorescent Studies in the Genus Clostridium. I. The location of antigens on the surface of Clostridium sporogenes during sporulation and germination
Authors: Walker P. D. , Batty Irene
Published: March 2008

Summary: Fluorescent labelled specific antisera against spores and vegetative cells have been used as stains to follow the antigenic changes that occur on the surface of Clostridium sporogenes during sporulation and germination.
The Use of Streptococcus faecalis as an Indicator of the Hygienic Condition of Meat Preserves and the Possibility of Interference by Aerococcus viridans
Authors: Lorincz F. , Incze K.
Published: March 2008

Summary: Few arguments may be put forward in favour of the use of Escherichia coli as an indicator of the hygienic condition of preserved meat products. In products of this type E. coli occurs only rarely. The proposal, which is supported by logical considerations and practical experience, to replace this organism by Streptococcus faecalis as an indicator of possible faecal contamination is strongly upheld by the authors. However, it is necessary to stress that the ubiquitous micro‐organism, Aerococcus viridans, occurs frequently in preserved meat products and, as it strongly resembles Strep. faecalis, may cause difficulties in the hygienic evaluation of such foods. The morphological and biological characteristics found suitable for differentiating these two organisms are described. Results supporting the view that Aerococcus, Pediococcus and Gaffkya be considered as distinct genera are also given.
The Adaptation of the Immunofluorescence Technique for Use in Bacteriological Investigations of Plant Tissue
Authors: Paton A. M.
Published: March 2008

Summary: The preparation of plant tissue for examination by the fluorescent antibody technique is described. The procedures suggested are intended to overcome some of the major obstacles encountered and the efficacy of the method for plant investigations is upheld by its successful application in a simple test system.
The Distribution of Yeasts on Cider Apples
Authors: Bowen J. F. , Beech F. W.
Published: March 2008

Summary: The distribution of yeasts on cider apples has been studied in orchards of the main cider‐making counties of England. The typical fruit flora consisted almost entirely of small numbers of weakly fermentative, nonsporing yeasts. No species was found to be completely characteristic of a particular apple variety, but there were differences in the yeast flora of orchards in different counties.
Cellulolytic Bacteria Isolated from the Large Intestine of the Horse
Authors: Davies M. Elizabeth
Published: March 2008

Summary. A technique for isolating cellulolytic bacteria from the large intestine of the horse is described. Isolates included two Gram‐negative rods resembling some members of the genus Bacteroides, a Gram‐negative sporeforming organism resembling Bacillus cellulosae dissolvens and several other unidentified bacteria. Some of the latter resembled cellulolytic bacteria isolated from the rumen in the past.
Characteristics of an Organism Causing Spoilage in an Orange Juice Beverage
Authors: Lott A. F. , Carr J. G.
Published: March 2008

Summary. An organism causing an off‐flavour in an orange juice drink is described. Morphological and biochemical properties of this organism, which produces a characteristic coral pink growth on most media, are also reported. Possible relationships with similar organisms known to occur in fruit juices and on fruits are discussed.
The Influence of a Change in Farm Dairy Practice on the Bacterial Flora of Fresh and Stored Raw Milk
Authors:   The late Constance Higginbottom, Jones Susan M. , Taylor Margaret M.
Published: March 2008

Summary. The change in farm dairy practice described resulted in an increase in the percentage of pseudomonads isolated from milks stored at 22, 15 and 5° and in the numbers of Gram‐negative rod cultures resistant to hypochlorite.
The Classification of Bacillus thuringiensis
Authors: Norris J. R.
Published: March 2008

Summary. Forty‐six isolates of protein crystal‐forming bacteria pathogenic for insects were studied in an attempt to correlate classifications based on biochemical reactions, flagellar antigens, and esterase patterns obtained when cell extracts were analysed by electrophoresis in starch gel.

Nine serotypes were represented, one being subdivided into two subtypes on the basis of secondary H antigens. There was a close correlation between the serological classification and that based on esterase analysis. The relationships between the three types of classification are described and the significance of esterase analysis in this context is discussed.
The Differentiation of Various Strains of Clostridium botulinum and Transformation Experiments with Type E
Authors: Skulberg A. , Hausken O. W.
Published: March 2008

The colonial forms and other characteristics of toxigenic and less toxigenic (hypotoxigenic) variants of Clostridium botulinum types A, B, C, D and E are described. In addition to differences in the appearance of the colonies the hypotoxigenic variants were able to produce larger numbers of spores. Transformation from one form to the other was found when they were grown in Robertson's meat broth to which sterile culture filtrates (boiled or unboiled) from the other form was added. A transformation from hypotoxigenic variants to toxigenic forms was also found when hypotoxigenic forms were grown in Robertson's medium to which the sterile culture filtrate (boiled or unboiled) of a strain of Cl. welchii had been added. The possibility of contamination of the cultures is emphasized.

A final appraisal of the situation must be reserved until experiments with single cell isolates have been performed.
Colonial Morphology and Fluorescent Labelled Antibody Staining in the Identification of Species of the Genus Clostridium
Authors: Batty Irene , Walker P. D.
Published: March 2008

The morphological and colonial appearances of a number of species of Clostridium are described and illustrated. The advantages of surface culture on appropriately supplemented media on stiff agar plates for the isolation and purification of anaerobic organisms are given. The use of fluorescent labelled antibody technique in the diagnosis of anaerobic disease is discussed.
The Resistance of Spores of Clostridium botulinum Type E to Heat and Radiation
Authors: Roberts T. A. , Ingram M. , Skulberg A.
Published: March 2008

Spores of Clostridium botulinum type E have been screened for resistance to heating in aqueous suspension at 60, 70 and 80°. D176 ranged from <0·33 min to 1·25 min. z values of eight strains were between 9·0 and 10·7, and for one strain was 7·4.

Radiation survivor curves have been plotted for nine strains, and a further nine strains screened. The “shoulder” extends to about 0·4 megarad, whereafter the curve becomes exponential within a D value from 0·065 to 0·16 megarad.
Some Observations on OS Variants of Clostridium botulinum Type E
Authors: Hobbs G. , Roberts T. A. , Walker P. D.
Published: March 2008

Three strains of OS variants of Clostridium botulinum type E (Dolman, 1957) have been studied using additional biochemical tests and fluorescent antisera. The relationship of these organisms, and other nontoxic clostridia resembling Cl. botulinum, to typical toxic strains is discussed.
Surface Antigenic Changes in Bacillus cereus during Germination and Sporulation as Shown by Fluorescent Staining
Authors: Walker P. D. , Batty Irene
Published: March 2008

Antigenic changes occurring on the surface of Bacillus cereus during sporulation and germination have been followed, using fluorescent labelled antibodies.
An Investigation of the Yeast Flora of Marine Fish from Scottish Coastal Waters and a Fishing Ground off Iceland
Authors: Ross Sheena S. , Morris E. O.
Published: March 2008

A total of 189 yeast isolates was obtained from samples taken from the gills, faeces, skin and mouths of fish caught in the Clyde Estuary, North Sea and Gletty Bank off the east coast of Iceland. The isolates comprised 6 genera, Debaryomyces, Torulopsis, Candida, Rhodotorula, Pichia and Cryptococcus, and 17 species. Debaryomyces kloeckeri comprised almost half the isolates (47·7%), followed by Torulopsis inconspicua (12·8%) and Candida parapsilosis (10·1%). Most of the isolates agreed closely with the description of a type species but some differences were noted.

The incidence of yeast occurrence was highest on the fish skin, followed by those from the gills and mouth, and then, in considerably lower proportions, from the faeces. No notable differences were observed in the species isolated from these locations.

Without exception D. kloeckeri was the predominant species in every geographical location of sampling, whereas both the occurrence and the proportion of isolates of other species varied in each area. All 16 types of fish sampled yielded yeasts and there were no indications that a characteristic yeast flora exists for each type of fish.
Bacterial Spoilage of Thawed Frozen Peas
Authors: Cavett J. J. , Dring G. J. , Knight A. W.
Published: March 2008

The main groups of bacteria developing in peas were isolated on differential media. Leuconostoc mesenteroides and Streptococcus lactis predominated and smaller numbers of catalase positive ‘coryneform’bacteria were also regularly present. Strep. cremoris, streptococci (group D), catalase positive cocci and Gram negative rods were less regularly isolated.

Bacterial spoilage of untreated peas was usually accompanied by the development of a yellow colour and a reduction in pH. In pure culture in peas leuconostocs and group N streptococci produced an acid pH while the catalase positive organisms produced alkali, sometimes with ammoniacal odours. In mixed cultures in peas the products of a leuconostoc and a ‘coryneform’tended to neutralize each other. A leuconostoc and a ‘coryneform’did not interfere with each others’growth when grown from similar inocula. The behaviour of streptococci is still being investigated. The type and rate of spoilage probably depends on the balance between ammonia production and acid production in the system.
A Bacterial Spore Test Piece for the Control of Ethylene Oxide Sterilization
Authors: Bebby Melanie M. , Whitehouse C. E.
Published: March 2008

Aluminium foil strips carrying varying numbers of spores of the Camp Detrick strain of Bacillus subtilis dried from water, 90% (v/v) methanol, 5 and 20% (v/v) serum, nutrient broth and isotonic saline were examined for their possible use as test pieces for the control of sterilization by ethylene oxide. Methanolic suspensions of these spores were found to be stable on storage, and foils carrying spores dried from methanol were the most reproducible and stable of those tested. The susceptibility of the test piece system could be controlled by varying the numbers of spores on each foil and the numbers of foils used per test.
The Effect of Recovery Medium on the Isolation of Staphylococcus aureus after Heat Treatment and after the Storage of Frozen or Dried Cells
Authors: Baird‐Parker A. C. , Davenport Elizabeth
Published: March 2008

The recovery of heated or dried cells of Staphylococcus aureus was best on media containing blood or sodium pyruvate. It is suggested that the catalase of S. aureus may be destroyed or its activity reduced by heating or drying and that one of the main reasons for the better recoveries on these media is that they are able to destroy peroxide. All media tested adequately supported the recovery of frozen cells.
Urea and Biuret as Nitrogen Sources for Rhizobium Spp.
Authors: Jensen H. L. , Schrøder Minna
Published: March 2008

Ability to utilize urea as nitrogen source proved to be universal in 80 fast and 40 slow growing strains of Rhizobium spp. from 23 genera of host plants, and also in 10 strains of Agrobacterium radiobacter. Rhizobium meliloti (32 strains) as well as A. radiobacter constantly failed to utilize biuret. Most rhizobia from other host plants (with 8 exceptions among 88) were able to use biuret as a somewhat suboptimal source of nitrogen, which was generally assimilated at a slower rate than urea and rarely resulted in the same amount of growth, particularly in the fast growing strains; in exceptional cases and mostly among the slow growing strains biuret appeared slightly superior to urea. Adaptation experiments showed that urease occurred as a constitutive enzyme in Rh. leguminosarum, while the biuret decomposing enzyme appeared to be inducible.
Coryneform Bacteria in Poultry, Eggs and Meat
Authors: Ayres J. C. , Torrey G. S. , Salzer R. H. , da Silva G. A. N.
Published: March 2008

Summary. In the course of investigations on the incidence of micro‐organisms on turkey giblets, in liquid egg and on meats, determinations were made of coryneform bacteria. Corynebacterium was the most common of 15 genera of micro‐organisms isolated from turkey giblets; Brevibacterium and Arthrobacter were also recovered. Species of Corynebacteriaceae were included among the most predominant contaminants in 9 of 17 samples of commercial liquid egg. Of these bacteria, Arthrobacter was most prevalent comprising 18% of the total number of isolates. Gram positive nonmotile rods recovered from fresh beef showed characteristics of Microbacterium and were similar to M. lacticum but failed to ferment lactose or survive temperatures higher than 60° for 30 min.
An Attempt to Increase the Heat Resistance of Microbacterium lacticum
Authors: Anagnostopoulos G. D. , Seaman A. , Woodbine M.
Published: March 2008

Summary. An attempt to increase the heat resistance of two strains of Microbacterium lacticum was made by exposing cells dispersed on an agar surface to 72° for two different times. Eighteen successive subcultures from survivors gave no increase in the proportion of heat resistant cells. There was no change in the ratio of the percentages of cells surviving the different treatments, an indication that there was no change in the overall heat resistance. With both strains the changing proportions of colonies developing on the 3rd and 5th day of incubation demonstrated the damaging effect of increasing the time of exposure at 72° but did not indicate any increase in heat resistance. The theoretical implications of these findings are discussed.
The in vitro Resistance to Antibiotics of Mycoplasma mycoides var. capri
Authors: Chelton E. T. J.
Published: March 2008

Summary. Resistance to dihydrostreptomycin, chloramphenicol and oleandomcin has been induced in vitro in a strain of Mycoplasma mycoides var. capri. The chloramphenicol resistant strain showed high resistance to oleandomycin, but the converse was not observed. The same cross resistance was also found, but to only a very small extent, in Staphylococcus aureus and Streptococcus faecalis. No cross resistance was found in three other species of bacteria examined. The osmotic lysis of the normal and the chloramphenicol resistant strains of M. mycoides var. capri were similar.
The Bacterial Production of Glutamic Acid in Stored Comminuted Beef
Authors: Gardner G. A. , Stewart D. J.
Published: March 2008

Summary. In meat stored at 4, 9 and 15°, the free glutamic acid produced from the deamidation of glutamine resulted from bacterial activity, meat glutaminase playing little or no part. The percentage of glutaminase active bacteria increased from 40 in fresh meat to 100 after storage for 65 h at 15°; Pseudomonas‐Achromobacter spp. predominated after 41 h at 15°. The glutaminase of a typical pseudomonad was optimally active at 36° and at pH 5 and appeared to be constitutive in nature.
A Determinative Scheme for the Fluorescent Plant Pathogenic Pseudomonads
Authors: Lelliott R. A. , Billing Eve , Hayward A. C.
Published: March 2008

Summary. The differential value of 15 characteristics was studied for the determination of plant pathogens in the fluorescent group of the genus Pseudomonas. All but 2 of the 161 pathogenic cultures and the 15 nonpathogenic cultures examined could be placed in one of 5 groups on the basis of tests for: oxidase, potato soft rot, arginine dihydrolase, levan production and a hypersensitivity reaction in tobacco leaves. Tests for production of acid from sucrose, nitrate reductase and a lipase for margarine were useful as subsidiary determinants. Aesculin hydrolysis, gelatinase and tyrosinase tests, and the production of a blue fluorescent pigment were of little or no value at the group level, and hydrolysis of Tween 80 and the catalase reaction had no differential value. With the exception of Ps. tolaaii and two cultures of questionable pathogenicity, the pathogens studied could be separated readily from the few nonpathogens studied. A determinative scheme for plant pathogenic fluorescent pseudomonads is proposed to serve until the taxonomy of the group is better understood.
Four New Bacteriophages of Bacillus thuringiensis
Authors: Chapman Heather M. , Norris J. R.
Published: March 2008

Summary. The morphologies of 4 new bacteriophages active against various strains of Bacillus thuringiensis have been examined by electron microscopy. The sensitivity patterns to these bacteriophages of B. thuringiensis strains and of other Bacillus spp. are described.
The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of Clostridium sporogenes (PA 3679/S2)
Authors: Roberts T. A. , Gilbert R. J. , Ingram M.
Published: March 2008

Summary. In 3% and 6% (w/v) sodium chloride solutions the heat resistances of spores of Clostridium sporogenes were the same as in water. Heating to give a 0.1% survival rendered the surviving spores more sensitive to inhibition by sodium chloride in the recovery medium.
Pre‐inoculation of Lucerne Seed
Authors: Fraser Margaret E.
Published: March 2008

Summary. Two methods by which lucerne seed may be inoculated several weeks before sowing have been developed. Calcium sulphate, as a coating on the seed and as a granule, provides a porous carrier for the inoculum of Rhizobium meliloti which is dried onto it from a suspension in milk and sucrose. Inoculated granules sown as a dry mixture with the seed made a more effective use of the inoculum in laboratory nodulation tests than the coated seed.
A Study by High Voltage Electrophoresis of the Amino Acid Decarboxylases and Arginine Dihydrolase of Bacteria Isolated from the Alimentary Tract of Pigs
Authors: Cheeseman G. C. , Fuller R.
Published: March 2008

Summary. The use of high voltage paper electrophoresis for studies on the breakdown of amino acids by bacteria is described. Examination of a number of different isolates from the alimentary tract of the pig showed that the decarboxylase activity was restricted to Escherichia coli and one strain of Lactobacillus fermenti. In some isolates studied the optimum pH of activity differed from those previously reported for similar systems, being higher for ornithine, glutamic acid and lysine decarboxylases. The heterofermentative lactobacilli all converted arginine to ornithine and this may contribute to the final level of putrescine in the gut by providing a substrate for the ornithine decarboxylase of E. coli.
Biocidal Activities of Glutaraldehyde and Related Compounds
Authors: Rubbo S. D. , Gardner Joan F. , Webb R. L.
Published: March 2008

Summary. Glutaraldehyde in 2% aqueous alkaline solution is rapidly bactericidal and sporicidal, killing 99.99% of the spores of Bacillus anthracis and Clostridium tetani in 15 and 30 min, respectively. It exhibits some degree of tuberculocidal activity, but it appears to be inferior to several other disinfectants when challenged with a large inoculum. Fungicidal action has been demonstrated but not assessed quantitatively. Evidence is presented to show that biocidal activity depends on the availability of two free aldehyde groups in the molecule.
Factors affecting the Recovery of Gamma Irradiated Escherichia coli
Authors: Cook A. M. , Widdowson Jean P.
Published: March 2008

Summary. Two methods of viable counting have been compared for unirradiated and γ irradiated Escherichia coli NCTC 5933. The spread plate method has been shown to be more reproducible than a serial dilution method in a liquid medium, but the survivor‐dose curves of γ irradiated bacteria obtained by the two methods were identical. The spread plate method was used to compare the survival of γ irradiated E. coli on peptone agar and on a synthetic glucose‐salts agar over a range of survivor levels of c. 9 log cycles. The log % survivor‐dose curve was linear for the synthetic medium but had a double exponential shape for the peptone agar. Recovery was much higher on peptone than on a synthetic medium. Using a tube dilution method in a liquid glucose‐salts medium, 19 l‐amino acids were tested for their effect on recovery. The slight increases in number of survivors attributable to some amino acids were associated with a change in the first part (100–1% survivors) of the curve rather than an alteration in final slope. The phosphate concentration of the solid synthetic medium markedly affected its ability to recover γ irradiated cells.
Novobiocin Resistance and the Classification of Staphylococci and Micrococci
Authors: Mitchell R. G. , Baird‐Parker A. C.
Published: March 2008

Summary. Isolates of staphylococci and micrococci, 105 in all, classified according to Baird‐Parker's classification (Baird‐Parker, 1963,1965) were examined for their sensitivity to novobiocin. All of the staphylococci were sensitive to novobiocin as also were strains of Micrococcus luteus and M. roseus. Almost all strains belonging to Micrococcus subgroups 1–6 were resistant to novobiocin.
Preservation of Vibrio fetus by Freeze Drying
Authors: Garvie Ellen I.
Published: March 2008

Summary. Vibrio fetus can be successfully freeze dried using the growth from thioglycollate blood agar. This medium is unsatisfactory for estimating the numbers of surviving organisms after freeze drying and storage. For this purpose a liquid medium containing 0.05% agar has been satisfactory. The long term storage of lyophilized preparations of V. fetus has not been fully investigated.
Some Preliminary Observations on the Location of Esterases in Bacillus cereus
Authors: Baillie Ann , Thomson R. O. , Batty Irene , Walker P. D.
Published: March 2008

The enzymes of Bacillus cereus capable of hydrolysing thiolacetic acid were located within the bacterial cell during different stages of the growth cycle. The significance of the results is discussed.
Use of Formaldehyde for the Disinfection of Hospital Woollen Blankets in Laundering
Authors: Dickinson J. C. , Wagg R. E.
Published: March 2008

The value of formaldehyde in the penultimate or last laundering rinse is assessed, using a micrococcus and Escherichia coli as the indicator organisms. Experiments demonstrating a residual disinfecting effect of dry formaldehyde treated blankets against the micrococcus are also described.
Inactivation of Bacterial Spores by Visible Radiations
Authors: Futter B. V. , Richardson G.
Published: March 2008

Exposure to visible radiations results in a decrease in viable count of spores of Bacillus subtilis and Clostridium welchii. This inactivation is partially reversible if a period of storage at 37° in the dark intervenes before plating. The recovery of light damaged spores is improved by the presence of dextrose in the counting medium.
Cultural and Symbiotic Properties of Rhizobia from Egyptian Clover (Trifolium alexandrinum)
Authors: El Essawi T. M. , Abdel Ghaffar A. S.
Published: March 2008

The morphological, cultural, biochemical and symbiotic properties of rhizobial strains isolated from Egyptian clover (Trifolium alexandrinum) were compared with those of strains from Denmark, England, Czechoslovakia and U.S.A. All were microscopically similar and showed normal growth on agar slopes, in broth and in milk. Some local but none of the foreign strains grew at 35° and in 5% NaCl solution. Differences in the reduction of nitrate, fermentation of carbohydrates and utilization of organic acids were apparent. Most Egyptian clover strains improved growth of the host plant, as measured by dry weight and nitrogen content. Egyptian clover strains formed only ineffective nodules on red clover (T. pratense). In general, Egyptian clover was effectively nodulated by foreign clover rhizobia.
Biochemical and Serological Characters of Three Strains of Streptococci Previously Reported as Streptococcus crernoris Isolated from Deep‐frozen Peas after Thawing
Authors: and J. J. CAVETT , GARVIE ELLEN I.
Published: March 2008

Cavett, Dring & Knight (1965) identified arginine negative, group N streptococci isolahd from deep‐frozen peas after thawing as Streptococcus cremoria. Three further isolates of such organisms have been studied in detail and although having certain properties in common with Strep. cremoris, they have others which exclude them from this species and also from other species of group N streptococci so far described. The original streptococci were probably wrongly designated.
Combined Effect of Water Activity, pH and Temperature on the Growth of Clostridium botulinum from Spore and Vegetative Cell Inocula
Authors: Baird‐Parker A. C. , Freame Barbara
Published: March 2008

The initiation of vegetative growth by spores in Reinforced Clostridial Medium (RCM) adjusted to different water activities (aw) by the addition of NaCl or glycerol does not depend solely on the aw of the medium; minimum aw at which spores of Cl. botulinum types A, B and E could initiate growth were higher in the media containing NaCl. The minimum aw at which vegetative cell inocula could grow were similar to those at which spore inocula could initiate growth. The combined effect of lowering the pH and aw of the medium was to increase the minimum at which spores of types A and E could germinate and also increase the minimum at which spore and vegetative cell inocula of Cl. botulinum types A, B and E could initiate growth.
Sporulation of Mesophilic Clostridia
Authors: Roberts T. A.
Published: March 2008

The commoner mesophilic clostridia have been screened for sporulation in several meat and other media. A method employing enriched spent medium has also been evaluated. A cooked meat medium based on Hartley's digest broth supported sporulation of more species than any other medium examined.
An Investigation into the Interaction between Iodine and Bacteria
Authors: Brandrick Angela M. , Newton J. M. , Henderson G. , Vickers J. A.
Published: March 2008

The interaction between aqueous solutions of radioactive iodine (131I) and washed suspensions of Escherichia coli and Staphylococcus aureus has been investigated. The conditions of the experiments were such that the bacteria were killed and no free iodine remained. Most of the iodine reacted with the bacteria by an oxidation‐reduction process, but halogenation also took place.
A Double Layered Plate Method for the Detection of Microbial Lipolysis
Authors: Alford J. A. , Steinle Elsie E.
Published: March 2008

A double layered plating procedure has been adapted for the determination of lipolysis by micro‐organisms. The base layer is prepared by mixing any fat, oil or triglyceride with Victoria Blue B and agar in a blender. Layers 2–3 mm thick are poured, allowed to solidify and overlaid with a suitable nutrient medium. This procedure allows considerable flexibility in the choice of fat as well as of nutrient medium. If lipolytic counts are desired, dilutions can be placed on the surface of the base layer prior to pouring the nutrient medium. Data are presented to show that no single fat or nutrient medium is suitable for all micro‐organisms. Acid production from carbohydrates in the medium rarely caused confusion in recognizing lipolysis.
Relationship between Carbon Dioxide Production and Growth of Pure Strains of Bacteria on Porcine Muscle
Authors: Gardner G. A. , Carson A. W.
Published: March 2008

The growth of a Pseudomonas sp., an Enterobacter sp., Kurthia zopfii, Microbacterium thermosphactum and a Lactobacillus sp. in pure culture on porcine muscle at 16 and 2° was examined in both open and gas‐tight systems. The CO2 in the headspace of the gas‐tight containers was produced by the muscle and by the bacteria. The Gram negative bacteria produced much lower amounts of CO2 than the Gram positive organisms. Data on the effects of CO2 on the growth of each bacterium at 16 and 2° are presented.
Psychrophilic Spoilage Bacteria of Fish
Authors: Shaw B. G. , Shewan J. M.
Published: March 2008

Sterile press juice from raw muscle of cod and ethylene oxide — sterilized cod muscle blocks were used to determine the spoilage potential of representative bacterial species present on cod, and to ascertain the incidence of spoilers on whole gutted fish during storage in ice. Growth and spoilage rates of selected cultures were studied between — 6° and +6°. A high proportion of Pseudomonas spp. spoil fish at 0.6° particularly members of groups II, III, and IV. The proportion of active spoilers of the total viable population on fish does not alter markedly during spoilage and remains below 25%. Growth of and spoilage by single Pseudomonas spp. is evident at — 3° even after a period of about 3 weeks.
Psychrophilic Spoilage Bacteria of Poultry
Authors: Barnes Ella M. , Impey C. S.
Published: March 2008

The organisms most commonly found growing on poultry carcases stored at 1° are pigmented and nonpigmented strains of Pseudomonas, Pseudomonas putrefaciens and strains of Acinetobacter. A comparison of total viable counts at 20 and 30° using stored turkeys, showed that certain strains could not be recovered at the higher temperature. When inoculated into minced breast and leg muscle, it was found that the pigmented and nonpigmented strains of Pseudomonas grew well in both muscle tissues. Strains of Acinetobacter groups B and C failed to grow in the breast muscle but grew in the leg muscle, Acinetobacter C growing much more rapidly than Acinetobacter B. The growth of Ps. putrefaciens was much faster in the leg muscle than in the breast muscle. These differences could partially be explained by differences in pH, the breast muscle having a pH value 5.7—5.9 compared with a pH value 6.4—6.7 for the leg muscle. The possible significance of these results in relation to the distribution and growth of these organisms on the chicken or turkey carcase is discussed.
Two Improved Media for Isolating and Enumerating Enterococci in Certain Frozen Foods
Authors: Lachica R. V. F. , Hartman P. A.
Published: March 2008

A direct plating method was employed in a comparison of two newly modified selective media, Tween‐carbonate (TC) and thallous acetate‐citrate (TAC) agars, and 4 other selective media, M‐enterococcus (ME) thallous acetate (TA), KF‐streptococcus (KF) and citrate‐azide (CA) agars, for enumerating enterococci in some frozen foods. Pure cultures of enterococci yielded comparable counts on TC, TAC, TA, KF and CA agars. When frozen food samples were plated, enterococcal counts on TA agar were generally higher than counts obtained on TAC, ME, TA or KF agars; TC and TAC agars were more selective than the other media tested. The TC agar at pH 6 inhibited enterococcal growth in the absence of bicarbonate. TC and TAC agars were the most suitable for isolating the interococci both qualitatively and quantitatively.
Evaluation of Methods Used in Counting Azotobacters
Authors: Abd‐el‐Malek Y. , Ishac Y. Z.
Published: March 2008

The common methods of counting Azotobacter spp. in soil, colony counts and MPN, were compared using cell suspensions of densities determined by direct microscopic counts. A highly significant positive correlation was found between the surface‐plate, MPN and total cell counts, but the MPN estimations approximated total cell counts much more closely. Inclusion of 1‐1.5 g of agar/l of the liquid medium enhanced multiplication of azotobacters and facilitated the recording of growth in MPN estimations.
Distribution of Psychrophilic Micro‐organisms in Different Dairy Environments
Authors: Dempster J. F.
Published: March 2008

421 cultures of psychrophilic bacteria, yeasts and moulds obtained from 8 sources were characterized to genus and species level by standard tests. 43% were Pseudomonas spp., 20%Achromobacter spp., 11.6% coli‐aerogenes bacteria and 10.2% flavobacteria. The remaining cultures were classified as Paracolon and Aeromonas spp., coryneform bacteria, micrococci, yeasts and moulds. 339 isolates were tested for lipolytic activity on tributyrin and butter fat agars. Results indicated that 232 (68.5%) and 215 (63.3%) were lipolytic on tributyrin and butter fat respectively.
Microbiological Sampling of Surfaces
Authors: Favero M. S. , McDade J. J. , Robertsen J. A. , Hoffman R. K. , Edwards R. W.
Published: March 2008

This report summarizes the 4 basic methods for the microbiological sampling of surfaces. Whereas no single assay procedure can characterize completely the microbial elements on a surface, the rinse technique is probably the most accurate for enumerating viable micro‐organisms, and the direct surface agar plating technique is the best for enumerating particulates containing viable micro‐organisms. However, the convenience of other methods, such as the agar contact method, will often be the dominant factor in the selection of a sampling method.
A Note on the Vitamin Requirements of Some Coryneform Bacteria from Soil and Herbage
Authors: Owens J. D. , Keddie R. M.
Published: March 2008

The nutritional requirements of 12 strains of coryneform bacteria were examined. Specific vitamin requirements were determined for 7 strains but the remaining 5 strains did not grow in any of the defined media used. Four strains showed vitamin requirement patterns which have not previously been reported for coryneform bacteria. These patterns were biotin + pyridoxal; thiamine + pyridoxal; thiamine + riboflavin + vitamin B12 (stimulatory); and biotin + thiamine + pantothenate + riboflavin.
Use of Germ‐free Mice for Testing Human Isolation Systems
Authors: Barnes R. D. , Holliday Jean , Cook R.
Published: March 2008

Germ‐free mice were introduced to test the efficiency and use of a human isolator designed to prevent the entry of viable bacteria. The mice remained free from bacterial contamination for the total period of 7 days spent in the isolator. The use of germ‐free mice for testing systems of contamination control is discussed.
A Microbiological Survey of British Fresh Sausage
Authors: Dowdell Marilyn J. , Board R. G.
Published: March 2008

This survey indicated that British fresh sausages contain 1‐5000 × 105 viable organisms/g, with Microbacterium thermosphactum predominant in the majority of samples. With lightly contaminated sausages, yeasts were abundant. They made a meagre contribution, however, in samples containing >1.0 × 107 organisms/g. In such material, members of the Pseudomonas–Achromobacter complex tended to be plentiful. Coliaerogenes organisms were recovered from the majority of samples, their numbers ranged from 1.3 to 2400 × 102/g. A similar situation obtained with Group D streptococci. Little change in the size of the microbial populations occurred during brief periods of storage but there was evidence of change in the composition of the flora. Fermentative organisms such as microbacteria and yeasts developed at the expense of the aerobic Gram negative organisms. Lactic acid bacteria made only a small contribution to the initial populations of sausages and their number did not increase appreciably when the commodity was held overnight under refrigeration or at room temperature.
Survival of Heated Streptococcus faecalis as Affected by Phase of Growth and Incubation Temperature after Thermal Exposure
Authors: Beuchat L. R. , Lechowich R. V.
Published: March 2008

Effects of the growth phase of 3 Streptococcus faecalis strains on heat resistance at 60° was studied. During the initial and middle logarithmic growth phases no resistance to 60° was found. Organisms heated in a stationary phase of growth were incubated at temperatures ranging from 45 to 7.3° to determine the effect of incubation temperature on their survival. Maximum survival of heated organisms was observed at optimum growth temperatures of c. 30°. The incubation time required for maximum recovery was longer for heated than for unheated organisms, regardless of the incubation temperature.
Comparison of the Action of Vantocil, Cetrimide and Chlorhexidine on Escherichia coli and its Spheroplasts and the Protoplasts of Gram Positive Bacteria
Authors: Davies A. , Bentley Muriel , Field Barbara S.
Published: March 2008

The actions of chlorhexidine, cetrimide and Vantocil (the hydrochloride of a polymeric biguanide) on bacteria and spheroplasts or protoplasts derived therefrom have been compared. Lysis of Escherichia coli spheroplasts by chlorhexidine or cetrimide is due to rupture of the cytoplasmic membrane. Membranes ruptured with cetrimide can reform to give small, empty envelopes. With increasing concentrations of cetrimide or chlorhexidine more and more granules appear in the cytoplasm, increasing in size with increasing concentration, until the structure becomes transformed to a granular body similar in size to the original spheroplast. With chlorhexidine or Vantocil this now electron‐dense body is rigid, but with cetrimide it collapses to a flat disc which does not lyse. The granules appear to consist of coagulated cytoplasm. This effect of excess of these antiseptics not only prevents osmotic lysis of the spheroplast or the collapsed disc but renders them immune to lysis by a variety of chemical agents. In isolated cytoplasm, chlorhexidine or cetrimide causes precipitation over a narrow range of concentrations but greater than those required for lysis. With Vantocil precipitation occurs gradually over a wide range of concentrations, starting at concentrations equal to those which cause a limited amount of lysis of the spheroplast or a relatively small increase in permeability of intact bacteria. Lanthanous and uranyl ions also precipitate cell contents but do not lyse spheroplasts; spheroplasts treated with these ions are protected from lysis by other agents.
Studies Arising from Observations of Osmophilic Yeasts by Phase Contrast Microscopy
Authors: Scarr M. Pamela
Published: March 2008

Osmophilic yeasts growing in concentrated sugar solutions vary in cell density with age and activity. Microscopic observations with phase contrast by Barer & Joseph's (1958) technique have confirmed this with all strains examined. Examination of syrups containing a culture of Saccharomyces rouxii indicates that growth is limited to these high concentrations owing to the physiological dryness of the habitat. However, some growth does take place, even in the film of molasses surrounding the sucrose crystal in stored raw sugar.

At c. 60% (w/w) of dissolved solids it is possible to identify active cells microscopically. Therefore the examination of raw sugar consignments for such cells is a rapid way of indicating whether the sugar is likely to deteriorate on storage.
Some Modifications to Dawson's Continuous Cyclone Column Culture Apparatus
Authors: Carr J. G. , Skerrett E. J. , Tucknott O. G.
Published: March 2008

Alternatives to Dawson's pneumatic levelling device have been devised so that the machine can be operated without loss of volatile substances from substrate or end product. The cyclone column has been modified by adding a side arm on which is fixed a level sensing device. Two methods for sensing the liquid level are described. The first is a light‐beam/phototransistor system actuated by the rise and fall of a float; the second is a device capable of sensing a change in capacitance caused by movement of the liquid towards or away from a sensing probe. Either of these systems can be linked to a pump controlling the inflow of fresh medium. The manufacture of Fino sherry was chosen as an example of a process with a volatile substrate and end product because it involves the partial oxidation of ethanol to acetaldehyde by a Flor yeast.
Isolation and Identification of Clostridia from North Sea Sediments
Authors: Davies June A.
Published: March 2008

Using enrichment techniques, it was possible to isolate clostridia from marine sediments collected from 10 stations in the North Sea. Of the total number of isolates Clostridium bifermentans constituted 47% and Cl. welchii 21%, while Cl. sordellii constituted 18%. The remainder were unknown species. Evidence of cellulolysis was obtained, but no organism has as yet been isolated. No psychrophilic anaerobes were found.
The Performance of a Stable Version of Baird‐Parker's Medium for Isolating Staphylococcus aureus
Authors: Holbrook R. , Anderson Judy M. , Baird‐Parker A. C.
Published: March 2008

A stable version of Baird‐Parker's medium has been devised by modifying the method of preparation. Poured plates of the medium can be stored for up to 28 days at 4° without any loss of selectivity. Its performance is compared with the original Baird‐Parker's medium and 2 commercial formulations.
The Use of Serratia indica and Bacillus subtilis var. niger Spores for Tracing Sewage Dispersion in the Sea
Authors: Pike E. B. , Bufton A. W. J. , Gould D. J.
Published: March 2008

Experiments were conducted at 2 coastal sites to evaluate the suitability of Serratia indica and spores of Bacillus subtilis var. niger for tracing offshore and longshore dispersion of sewage released from submarine outfalls. Neither organism was found in the sea or the rivers studied prior to an experimental release and, whereas tracer spores persisted in the sea and the littoral zone for some days after release, S. indica disappeared within a few days. Where S. indica was released continuously from an outfall, it dispersed similarly to coli‐aerogenes bacteria. Both tracers were killed rapidly in seawater exposed to sunlight, but their mortality kinetics differed. Tracer spores did not die or germinate in the dark when suspended in sewage during 24 h or in seawater during 9 days, but death occured after 3 days in seawater exposed to sunlight. Spores dispersed offshore similarly to K82Br and to S. indica; because of this and their stability, it was thought that they could be used for measuring physical dilution independently of mortality. The continuous release of S. indica into the sea is suitable for measuring the pollution field around a discharge; adding single doses of either tracer yields information on dispersion processes and transit times to the shore.
Action of Biguanides, Phenols and Detergents on Escherichia coli and its Spheroplasts
Authors: Davies A. , Field Barbara S.
Published: March 2008

The bactericidal potency of groups of biguanides, phenols and detergents has been compared with that of the bis‐biguanide, chlorhexidine, and related to measurable effects of the compounds on bacteria. Biguanides, like chlorhexidine, precipitated bacterial cytoplasm and also lysed spheroplasts over a limited concentration range: higher concentrations prevented lysis. Certain phenols and detergents which lysed spheroplasts did not precipitate cytoplasm. All the compounds released radioactivity from isotopically labelled bacteria; at suitable concentrations, biguanides released more radioactivity than chlorhexidine, but at higher concentrations the amount of radioactivity released was reduced. Bactericidal activity correlated with both the ability to lyse spheroplasts and to precipitate cytoplasm from solution. The findings support the hypothesis that damage to the cell wall alone does not kill bacteria but an increase in permeability allows entry of the bactericide. Action of compounds on the cell wall is discussed in relation to a model of its ultrastructure.
A New Multiple Inoculator for Bacteriocine Typing
Authors: Merrikin D. J. , Terry C. S.
Published: March 2008

A new design of multiple inoculator for bacteriocine typing is described. The inoculator consists of a ridged aluminium roller and is used in conjunction with an aluminium inoculum tray. The inoculator permits more certain sterilization than previous designs, which are briefly reviewed.