bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Porcine Mycoplasmas on Pig Tracheal Organ Cultures
Authors: Pijoan C. , Roberts D. H. , Harding J. D. J.
Published: March 2008

Summary: Tracheal organ cultures were made from 2–3 week old pigs. Tracheal rings were used to assess the pathogenicity of Mycoplasma hyopneumoniae, M. hyorhinis, M. granularum and M. hyosynoviae. Both serum‐resistant and serum‐sensitive strains of M. hyorhinis had a marked effect on ciliary activity and caused necrosis of the epithelium. Mycoplasma granularum and M. hyosynoviae caused cessation of ciliary movement, but to a less extent, and necrosis did not occur. With M. hyopneumoniae, the infected organ cultures survived longer than the control cultures.
Growth of Pure and Mixed Cultures of Micro‐organisms Concerned in the Treatment of Carbonization Waste Liquors
Authors: Jones G. L. , Carrington E. G.
Published: March 2008

Summary: Three strains of bacteria responsible for the destruction of the major constituents of carbonization waste liquor were isolated from a laboratory scale, activated sludge plant successfully treating such a liquor. Of the 3 strains one was able to grow on thiocyanate; the other 2 strains grew well on phenol. Behaviour of these organisms in pure and mixed culture showed marked differences: in pure culture, growth of the thiocyanate‐degrading strain was unaffected by the presence of 100 mg of phenol/l, but in mixed culture, active growth of another organism on the phenol completely inhibited growth on the thiocyanate. Batch and continuous culture experiments were made with 2 organisms competing for phenol. Both stimulation and inhibition of growth were found, dependent on the ratio between the concentrations of organisms present.
The Fluorescent Antibody Technique for the Detection of Salmonella in Routine Use
Authors: Gibbs P. A. , Patterson J. T. , Murray J. G.
Published: March 2008

Summary: The direct and indirect fluorescent antibody technique (FAT) were compared with cultural methods for detecting salmonellae in meat products, animal feedingstuffs, poultry carcase swabs, giblets and poultry plant and equipment swabs. Salmonellae were not isolated from meat products and fluorescent cells were not seen on slides prepared by either FAT. The indirect and direct FAT recorded 13% and 9% respectively, false positive results, with samples of animal feedingstuffs, but the direct FAT recorded a single false negative result. Salmonellae were not isolated from poultry carcase swabs but 3% and 4·5% respectively, of false positive results were obtained with the indirect and direct FAT. Salmonellae were isolated from both giblet samples and poultry plant swabs and both gave rise to false negative FAT results. Preliminary studies of the efficacy of the FAT for screening animal faecal material for salmonellae indicated that no single combination of enrichment broth and FAT gives unequivocal results, but the staining of smears from tetrathionate broth by either FAT gives rise to a high percentage of false negative results.
Malt Extract as Protective Medium for Lactic Acid Bacteria in Cryopreservation
Authors: Johannsen Elzbieta
Published: March 2008

Summary: Malt extracts prepared from barley and sorghum malts were used as media for preserving bacteria at ‐196°. The results are compared with those obtained with other protective substances such as dimethylsulphoxide, glycerol, malic acid, sucrose and sodium glutamate. The malt extract medium is recommended for use in the food industry.
The Removal of Nitrate from Solution by Floc‐forming Bacteria on Decomposing Cellulose Particles
Authors: Skinner F. A.
Published: March 2008

Summary: Cellulose particles in aerated liquid medium inoculated with activated sludge quickly became enveloped in floccular microbial growth (cellulose floc) able to assimilate nitrate rapidly from solution. Sedimenting the floc removed assimilated nitrogen, excess cellulose and biomass. At 18 and 22°, nitrate was removed from solution at 1·76 and 1·83 μg of nitrate‐N/ml/h, respectively. Similar results were found with floc formed by a cellulose decomposing isolate and some noncellulolytic floc‐forming bacterial contaminants. Washed preformed cellulose floc removed nitrate from dilute solution at 0·89 μg of nitrate‐N/ml/h at pH 7·1–8·6. The C : N ratio of the supernatant fluid changed rapidly as nitrate became exhausted; the significance of this is considered in relation to complete removal of C and N by further biological oxidation.
The Ecology and Classification of Strains of Lactobacillus collinoides nov. spec.: A Bacterium Commonly Found in Fermenting Apple Juice
Authors: Carr J. G. , Davies Patricia A.
Published: March 2008

Summary: Most heterofermentative lactic rods occurring throughout the cider industry are quite similar and form a fairly coherent group. The constituent bacteria are sufficiently different from other heterofermentative lactobacilli to be considered a new species. They have, therefore, been named Lactobacillus collinoides nov. spec. These occur most frequently in factories where sulphur dioxide, the only permitted preservative, is either used in small quantities or not at all.
The Effect of Ionizing Radiation on the Microbiological Content and Volatile Constituents of Spices
Authors: Tjaberg T. B. , Underdal B. , Lunde G.
Published: March 2008

Summary: Irradiation at a level of 0·5 Mrad decreased the number of surviving microorganisms in spices considerably and 1·58 Mrad sterilized them. Gas chromatography showed a slight increase in the amounts of volatile constituents with increasing dose. The amounts of permanent free radicals in the spices were negligible.
The Relationship between Methane Production and Concentrations of Hydrogen in the Aqueous and Gaseous Phases during Rumen Fermentation in vitro
Authors: Czerkawski J. W. , Harfoot C. G. , Breckenridge Grace
Published: March 2008

Summary: When rumen micro‐organisms were incubated in vitro with a wide range of concentrations of hydrogen (H) in the gas phase, the amount of methane produced was linearly related to the amount of H taken up. The rate of utilization of dissolved H for methane synthesis was close to the rate of entry of H into solution from the gas phase. Hydrogen produced from formate accumulated in the aqueous phase, but methane production was not related to its concentration.
The Role of Micro‐organisms in Waste Tip‐lagoon Systems Purifying Coke‐oven Effluents
Authors: Stafford D. A. , Callely A. G.
Published: March 2008

Summary. The population of aerobic bacteria present in the waters of a tip‐lagoon system being used to purify a coke‐oven effluent has been investigated. Though organisms capable of degrading phenol were detected, the total bacterial population was low, mainly due to a deficiency of orthophosphate and lack of aeration. Phenols can be removed from coke‐oven effluents by allowing them to percolate through columns of material from colliery waste tips. Bacteria need not be present for this to occur though the presence of bacteria capable of degrading phenol were detected in the liquid coming from such columns. Only traces of thiocyanate are removed. If a biological filter can be developed, as on columns packed with gravel, better removal of phenols and thiocyanate occurs, but it is doubtful if bacteria play any significant role in the purification of coke‐oven waste liquors percolating through large tips of colliery waste.
An Improved Selective Medium for Isolating Fluorescent Pseudomonads
Authors: Simon A. , Rovira A. D. , Sands D. C.
Published: March 2008

Summary. The addition of chloramphenicol (5–12·5 μg/ml) to novobiocin‐penicillin‐cycloheximide (NPC) medium improved the selectivity of this medium for counting and isolating fluorescent pseudomonads from sources in which they form a minor component of the microflora.
Further Studies on a Serum Nonantibody α Globulin with Antistaphylococcal Activity
Authors: Yotis W. W. , Lentino J. R.
Published: March 2008

Summary. Previous work in this laboratory indicated that normal human serum contains a pseudoglobulin which inhibited the growth and respiration of staphylococci. Studies with a variety of serum fractions suggest that antibacterial agent (ABA) and α globulin alone possess the antibacterial properties which distinguish them from all other fractions tested. ABA has been prepared from unfiltered and Seitz filtered (to remove the β lysin) sera, platelet‐rich plasmas of humans, rabbits, guineapigs and rats and assayed by a sensitive rapid radioisotopic technique. ABA is widely distributed among animal sera and, in contrast to the human ABA, requires a 2–4 fold increase in the concentration of coagulase necessary to demonstrate a comparable reversal of the antirespiratory effect. Immunological studies confirmed the nonantibody nature of ABA. ABA did not react with antisera to IgA, IgG, IgM, human β lipoprotein, haptoglobin, thyroglobulin, C‐reactive protein, ceruloplasmin, fibrinogen or antiserum to β lysin obtained from other workers. Of the various serum fractions tested only á globulin had any detectable antistaphylococcal activity.
The Microflora of Liquid Whole Egg Made from Incubator Reject Eggs
Authors: Mulder R. W. A. W. , Van Der Hulst Maria C.
Published: March 2008

Summary. The microflora of liquid whole egg made by centrifuging incubator reject shell eggs was investigated by examining a selection of colonies growing on different selective culture media. As a result of the method of manufacture micro‐organisms were present and of the 200 isolates characterized, most belonged to the Bacillaceae, Enterobacteriaceae, Lactobacillaceae, Micrococcaceae and Pseudomonadaceae. A pasteurization treatment showed the presence of a thermoresistant flora. Some representatives of the Bacillaceae and the Lactobacillaceae showed resistance to the heat treatment given.
Gliding Motility in Some Non‐spreading Flexibacteria
Authors: Perry L. B.
Published: March 2008

A plate technique for detecting gliding motility is described in which glass beads placed between agar surfaces and coverslips produced surrounding areas of liquid, thus allowing cells to move freely. Some relatively short non‐spreading flexibacteria glided obviously. The movements are described and also those of myxobacteria and a fimbriate twitching bacterium. Flavobacterium aquatile F36 glided and its taxonomic status is discussed.
Characteristics of Greek Isolates of Agrobacterium tumefaciens (E. F. Smith & Townsend) Conn
Authors: Panagopoulos C. G. , Psallidas P. G.
Published: March 2008

The characteristics of 51 Greek isolates (40 virulent and 11 avirulent) of Agrobacterium tumefaciens obtained from almond, peach, pear and grapevine were studied. Both biotypes of Keane, Kerr & New (1970) were recognized and the characterization of these extended with further tests. The position of 7 heterogeneous isolates which do not conform to the above biotypes is discussed. Biotype 2, widespread in Greece, was found in most hosts examined and seems to be of common occurrence. Grapevine isolates belonging to biotype 1 and to a third group were found to be host specialized. Evidence for the stability of tests used for the characterization of the organism is presented.
Serine Dehydratase from Bacteria
Authors: Nelson G. E. N. , Peterson R. E. , Ciegler A.
Published: March 2008

One hundred and seventeen strains of baeteria were assayed for L‐serine dehydratase activity. Proteus vulgaris NRRL B‐123 yielded c. 200 international units of dehydratase/g dry wt.
Evaluation of Spectinomycin Resistance as a Marker for Ecological Studies with Rhizobium spp.
Authors: Schwinghamer E. A. , Dudman W. F.
Published: March 2008

Resistance to the antibiotic spectinomycin has been examined as a possible marker to supplement streptomycin resistance in ecological or genetic studies with rhizobia. Single step spontaneous mutants resistant to high levels of spectinomycin were isolated from 8 effective strains representing 4 species of Rhizobium. There was no evidence of cross resistance to streptomycin, and streptomycin resistant mutants were not cross resistant to spectinomycin. Minor changes in antigenic characteristics examined by immunodiffusion in agar were detected for mutants from 2 strains but these variants were still identifiable with the parent strains. Partial or full loss of symbiotic effectiveness occurred in only c. 20% of the spectinomycin resistant mutants and the resistance marker was unchanged through one plant passage. It is concluded that spectinomycin resistant mutants properly evaluated for possible pleiolropic effects should provide a useful marker system for use alone or in combination with streptomycin resistance in Rhizobium.
Microbial Changes Leading to the Spoilage of Hung Pheasants, with Special Reference to the Clostridia
Authors: Mead G. C. , Chamberlain Audrey M. , Borland Edith D.
Published: March 2008

A spoilage problem affecting hung pheasants is described in which carcasses showed rapid greening and deterioration during hanging. No micro‐organisms were detected in samples of muscle tissue taken from abnormal carcasses but clostridia and often coli‐aerogenes bacteria were unusually abundant in the duodenum and in the remainder of the small intestine. The clostridia were mainly Clostridium bifermentans/sordellii or strains resembling Cl. welchii and these organisms outgrew all other bacteria in the duodenum under suitable hanging conditions. When grown at low temperatures strains of clostridia and Escherichia coli from pheasants produced large amounts of H2S which is concerned in the greening process. Some other properties of the clostridia are described and the significance of the spoilage problem is discussed.
Collagenolytic Activity of Hide Bacteria and Leather Decay
Authors: Woods D. R. , Rawlings D. E. , Cooper D. R. , Galloway A. C.
Published: March 2008

The numbers and collagenolytic activities of hide bacteria were determined before and after curing and were compared with leather decay gradings obtained from the finished leather. A correlation between the collagenolytic activity and bacterial numbers of both raw hide and leather decay populations was obtained. No correlation between collagenolysis or bacterial numbers and leather decay was observed with cured hide bacteria. Bacterial action during the raw hide stage was primarily responsible for hide decay. There was no significant difference (t 0·05) between the collagenolytic activities of bacterial populations obtained from neck and tail samples from hides of the same batch.
Analysis of the Intracellular Amino Acid Pool and Proteins from Whole Cells of Rhizobium japonicum
Authors: Lillich T. T. , Elkan G. H.
Published: March 2008

The amino acid composition of proteins from whole cells of Rhizobium japonicum was determined. The proteins contain only those amino acids commonly associated with bacteria and in ratios approximately equal to those which have been reported in other bacterial genera. Analysis of the intracellular amino acid pool showed relatively large amounts of alanine, glutamate and lysine. These amino acids are normally associated with the peptidoglycan layer of bacterial cell walls leading to speculation that the pool observed was for the synthesis of cell wall precursors rather than for general protein synthesis. The high levels of alanine relative to the other amino acids can also be explained by the operation of alanine dehydrogenase, (E.C. 1.4.1.1) which is an assiniilatory enzyme for ammonia.
A Selective Medium for Enumerating Salt Requiring Vibrio spp. from Wiltshire Bacon and Curing Brines
Authors: Gardner G. A.
Published: March 2008

A medium is described for the enumeration of salt requiring Vibrio spp. which are found commonly in the microflora of spoiled bacon. Data are presented on the selectivity of the medium in the examination of Wiltshire style bacon and curing brines.
The Influence of Temperature and Moisture on the Disinfecting Activity of Methyl Bromide on Infected Poultry Litter
Authors: Harry E. G. , Brown W. Burns , Goodship Gwen
Published: March 2008

At 25°, exposure of finely sieved poultry house litter for 20 h to methyl bromide (MeBr) gas at concentrations of 10–120 mg/l, i.e. concentration‐time (CT) products of 200–2400 mg h/l, resulted in a marked reduction in the number of bacteria present in terms of Salmonella typhimurium, Escherichia coli and micrococci. The activity of the gas was affected adversely by a reduction in temperature and by its application to litter of a high moisture content. Except with wet litter, a reduction of >99% of the Salm. typhimurium present resulted from exposure at 25° to gas concentrations as low as 10 mg/l (CT product, 200 mg h/l) and it was undetected in samples exposed to 40 mg/l at 25° (CT product, 800 mg h/l) or 80 mg/l at 10° (CT product, 1600 mg h/l). The significance of reductions of this order, in terms of the infectivity of the litter to chicks subsequently reared on it, is discussed. Escherichia Coli showed a susceptibility similar to that of Salm. typhimurium but micrococci were considerably more resistant.
The Effect of High Sugar Concentrations on the Heat Resistance of Vegetative Micro‐organisms
Authors: Gibson Barbara
Published: March 2008

Summary. The effect of sucrose or mixtures of sucrose and glucose, in the heating menstruum, on the heat resistance of 4 organisms, Salmonella senftenberg, Salm. typhimurium, Saccharomyces rouxii and Torulopsis globosa, was investigated and the results have been expressed in terms of D and z values against water activity (aw). The effect on the cell of sucrose solutions, both with and without heat, was also investigated. Measurements of cell volume obtained from phase contrast micrographs and of O.D. showed that as the sucrose concentration increased, the volume of the cell decreased. The increased heat resistance exhibited by cells in sucrose solutions of low aw is thought to be the result of a dehydration of the cell together with a reduction in the pore size of the cell wall.
Iodide Oxidation by a Marine Bacterium *
Authors: Gozlan R. S. , Margalith P.
Published: March 2008

Summary. Death of euryhaline fish in an aquarium was caused by iodine liberated in seawater by a marine bacterium. The isolation of a pure culture of Pseudomonas iodooxidans sp. nov., highly resistant to iodine, led to the elucidation of the mechanism involved. Iodides were oxidized to free iodine by an extracellular peroxidase system and hydrogen peroxide was generated by the bacteria. The importance of this finding is discussed in the light of current knowledge of the iodine cycle in nature.
The Presence of Clostridium botulinum in Indonesian Waters
Authors: Mortojudo J. W. , Siagian E. G. , Suhadi F. , Ward B. Q. , Ward W. M. S.
Published: March 2008

Summary. In initial surveys of Indonesian waters and marine animals, Clostridium botulinum, predominantly of types A and C, was detected in 10% of all enrichment cultures tested.
The Microbial Associations Developing on Experimental Trickling Filters Irrigated with Domestic Sewage
Authors: HALLS N. A. , Board R. G.
Published: March 2008

Summary. The bacterial flora of the film which developed on experimental trickling filters irrigated with domestic sewage was dominated by Acinetobacter and yellow‐pigmented Gram negative rod‐shaped organisms and it was deduced that purification in certain aerobic waste treatment processes may depend upon an association of these 2 organisms. Further evaluation of the operational procedures likely to have a selective influence on the microbial association which becomes dominant was made in studies using synthetic sewage.
The Effect of Rumen and Post‐Rumen Feeding of Carbohydrates on the Caecal Microflora of Sheep
Authors: Mann S. O. , ØRskov E. R.
Published: March 2008

Summary. When sheep were bottle‐fed with solutions of glucose, sucrose or maltose, so avoiding fermentation in the rumen, there was a marked increase in the number of caecal bacteria, with a higher percentage of viable bacteria, compared with caecal counts from sheep fed conventionally on carbohydrates. Bottle‐feeding also resulted in a redistribution of bacterial types, 40–46% of the flora comprising Gram positive rods and a significant increase in butyric acid and decrease in propionic acid in the caecal contents. Feeding cellulose suspensions by bottle or conventionally failed to produce significant differences in counts of cellulolytic caecal bacteria. When sucrose was infused in increasing amounts into the abomasum, Streptococcus bovis was the principal organism, isolated from faeces.
The Nitrifying Bacteria in Soils from Rothamsted Classical Fields and Elsewhere
Authors: Soriano S. , Walker N.
Published: March 2008

Summary. Ammonia oxidizing autotrophic nitrifying bacteria in soil samples from 3 classical Rothamsted fields and elsewhere were counted by a modified 2‐layered silica gel plating method. Counts ranged from 0‐18000/g of dry soil, the maximum number being found in the Broadbalk farmyard manure plot. Nitrosomonas europaea was isolated in pure culture and detected only in soils treated with dung or other organic fertilizer. Nitrosocystis coccoides and Nitrosospira spp. were found in other soils. Nitrobacter spp. were present in many soils and of the 18 pure cultures isolated there seemed to be 3, or possibly 4, different colony types.
The Doubtful Status of the SpeciesZymomonas anaerobiaandZ. mobilis
Authors: Dadds M. J. S. , Martin P. A. , Carr J. G.
Published: March 2008

Summary.During the course of an investigation ofZymomonasspp. in the brewing industry, a strain was isolated from different habitats and identified asZ. mobilis.It is the first occasion on which this species has been isolated from British beers. Closer examination of one isolate showed that it was different from the stock strain ofZ. mobilis, both in vitamin requirements and serology. Strains ofZ. anaerobiawere also isolated and it was possible to induce these bacteria to metabolize sucrose. Since the ability to utilize this sugar is one of the major differences betweenZ. mobilisandZ. anaerobia, and in view of the closeness of the G + C ratios, the whole question of whether 2 species ofZymomonasare justified is thrown into doubt.
Origin of Initial Microflora of Palm Wine from Oil Palm Trees (Elaeis guineensis)
Authors: Faparusi S. I.
Published: March 2008

Summary. In a study of the origin of the initial microflora of palm wine from the oil palm (Elaeis guineensis), micro‐organisms from parts of the immature spadix, the plant tissues around the point of tapping the tree, the palm leaves and the atmosphere around the palm trees, were isolated and examined. It was shown that the yeasts in fresh palm wine might have originated from those that colonize those parts of the palm which are covered with fluffy hairy outgrowths. These materials which surround the tapping hole are the stalk of the male inflorescence, the leaf petiole, the felt (a fabric‐like outgrowth of the frond petiole used to cover the tapping hole) and the cross strips. Another possible source of the yeasts was the xylem stream.
The Effect of Ultra Violet Light on the Symbiotic Effectiveness and Some Physiological Characteristics of Four Strains of Rhiozobium trifoli
Authors: Russell P. E. , Jones D. Gareth
Published: March 2008

Summary. UV light was used to induce mutations in 4 strains of Rhizobium trifolii. Mutations were found with modified acid production, generation time, polysaccharide production and symbiotic effectiveness on S184 white clover. Of 72 mutants examined, one was more effective than the parent, 9 had either similar or reduced effectiveness compared with their parental strains and the remainder were non‐infective. A significant correlation (P <0·05) was found between the effectiveness of the strains and their acid production on an agar medium but no such relationship was found in liquid medium. No other relationships were found between any of the physiological or symbiotic characteristics examined.
Actinomycete Variants with Impaired Differentiation: Production in High Yield, Recognition and Phenotypic Characterization in Seven Species
Authors: Nikitina Ekaterina T. , Kalakoutskii L. V.
Published: March 2008

Summary. When plated on mineral synthetic media with D‐fructose as a sole carbon and energy source 7 strains of actinomycetes belonging to different streptomycete species regularly produced secondary variant colonies in high yield. Beside the ability of strepto‐mycetes to utilize fructose as a sole carbon source, the following factors were shown to be of importance in the control of variational events: the state of the parent culture used for platings; the composition of fructose‐containing media used for the production of variants. Indole, anthranilate and phenol inhibited formation of secondary colonies by most strains. Phenotypically all the variants obtained shared in common the loss of ability to form secondary (aerial) mycelium and spores as well as a tendency of the substrate mycelium to fragment. These traits were shown to be: hereditarily stable on all media tested for variants derived from Streptcmyces ruber, Str. roseolus, Str. lateritius and Str. roseoflavus var. roseofungini; less stable and nutritionally affected for variants derived from Str. albocyaneus, Str. roseoflavus and Str. anthocyaneus; unstable on all except fructose‐containing mineral medium for the variants of Str. flavofungini. Vegetative growth of some of the variants obtained was not inferior to that of parent cultures; some variants produced increased amounts of intracellular antibiotics. Some implications of the reported findings are discussed.
Effect of Metal Cations and pH on the Antibacterial Activity and Uptake of Long Chain Fatty Acids
Authors: Galbraith H. , Miller T. B.
Published: March 2008

Summary. The bactericidal activity of long chain saturated fatty acids was antagonized by alkaline earth metals. The activity of linoleic acid was less effectively antagonized but was more sensitive to reversal by ferric and stannous ions. With increasing pH value the bactericidal activity of lauric acid decreased but that of the longer chain saturated acids increased. Both Gram positive and Gram negative bacteria reversibly adsorbed fatty acids. Uptake increased with decreasing pH value and increasing chain length. Although adsorbed to a lesser extent, the intrinsic activity of linoleic acid was greater than lauric acid. The uptake appeared to be non‐specific and governed by the physicochemical properties of both the acids and the bacterial cell surfaces. Sensitivity to the fatty acids increased with decreasing pH value. Protoplasts of Bacillus megaterium adsorbed fatty acids to a greater extent than whole cells. Resistance of the Gram negative Pseudomonas phaseolicola was not due to non‐adsorption of the fatty acids.
Radiation Resistance of Spores of Bacillus subtilis and B. stearothermophilus at Various Water Activities
Authors: Härnulv B. G. , Snygg B. G.
Published: March 2008

Summary. The radiation resistance of spores of Bacillus subtilis and B. stearothermophilus was determined under anoxic conditions in water vapour and in aqueous solutions of glucose and glycerol at various water activities. In water vapour, resistance of both kinds of spores increased slightly with decreasing water activity (aw). In glycerol solutions, a phase of rapid increase in resistance with decreasing aw was followed by a slower increase on further reduction of aw. This second phase was almost parallel to the water vapour curve, which, however, showed considerably lower resistance. The initial phase of rapid increase in resistance was also observed in glucose solutions.
Volatile Acid Production by Clostridium sporogenes under Controlled Culture Conditions
Authors: Anema P. J. , Kooiman W. J. , Geers Joyce M.
Published: March 2008

Summary. Clostridium sporogenes, grown under controlled culture conditions in a complex medium, starts to produce volatile acids at the end of the logarithmic growth phase when sporulation begins. Since, however, the amount and type of acids depend on the nature of the medium used, it is doubtful whether the volatile acid pattern can be used for identification and classification of proteolytic Clostridia without controlling culture conditions.
Observations on the Microbiology of Cooked Chicken Carcasses
Authors: Patterson J. T. , Gibbs P. A.
Published: March 2008

Summary. The residual microbial flora and the flora developing during storage at 1–3° and at 16°, of chicken carcasses cooked in a circulating moist air oven operated at 85°, have been studied. All parts of the carcasses reached and maintained 85° for at least 50 min, and the residual flora consisted largely of spore forming bacteria. The predominant residual species were Bacillus subtilis and Clostridium bifermentans. Non‐sporing bacteria were not detected after cooking nor after storage at 1–3° for up to 7 days. Storage at 16° for 3 days markedly increased the number of non‐sporing organisms although off‐odours typical of spoilage were not apparent until at least 10 days. Staphylococcus aureus and Salmonella spp. were not detected after cooking and storage and Cl. welchii was rarely isolated. It is concluded that poultry cooked by this method present a minimal risk of food‐borne infection or intoxication by these organisms if contamination after cooking is avoided, the carcasses are cooled rapidly to c, 3° and stored at this temperature or frozen.
Mechanism of Action of the Gonadal Steroids Producing Diminution of Growth of Staphylococcus Aureus
Authors: Fitzgerald T. J. , Yotis W. W.
Published: March 2008

Summary. Studies were undertaken to characterize the mechanism of action of the gonadal steroids responsible for decreasing growth of Staphylococcus aureus in vitro. Progesterone or testosterone at 20 μg/ml significantly increased the leakage of 14C activity from staphylococci pre‐loaded with 14C‐glucose. This enhancement of leakage was not detected with Gram negative micro‐organisms. Hormonal diminution of total uptake of alanine was relatively independent of temperature and of the phase of culture. Anaerobiosis increased the steroidal diminution of alanine uptake c. 2‐fold. Fraction‐ation of staphylococci following exposure to various 14C‐substrates in the presence of progesterone at 40 μg/ml did not reveal any distinctive influences on macromolecular syntheses. Entry of the labels into cellular pools, however, was altered for 8 of the 10 substrates tested. Exchange experiments detailed the effects of steroids on the efflux of internal alanine and lysine. With progesterone at 40 μg/ml, alanine effluxed from the internal pool 3 times as fast as from the corresponding controls. The opposite effect occurred with lysine and progesterone depressed its exit rate. The stepwise removal of cellular constituents indicated a preferential binding of hormones to cell wall components. Using 14C‐progesterone or 14C‐diethylstilbestrol, 24% and 29%, respectively, of the added hormone was firmly bound to mucopeptide preparations, compared to 1–5% bound to whole cells or isolated cell walls. We suggest that the hormones interfere with the integrated functioning of membrane‐associated processes.
The Effect of Alcohols on Growth and Lipase Formation by Staphylococcus aureus
Authors: Mates A.
Published: March 2008

Summary. The growth of Staphylococcus aureus 111 was inhibited by aliphatic alcohols. The extent of inhibition by primary n‐alcohols increased with the elongation of the chain. Secondary alcohols were less inhibitory than the corresponding primary alcohols. The inhibitory effect was influenced by the distance of the hydroxyl group from the end of the carbon chain. When the alcohols were added to the medium in sub‐inhibitory amount, enzyme synthesis by the bacteria was decreased, but there was no demonstrable inhibition of enzyme already formed.
The Effect of Sugars and Polyols on the Heat Resistance of Salmonellae
Authors: Corry Janet E. L.
Published: March 2008

Summary. The heat resistance at 65° of 3 strains of salmonellae in solutions of sugars or polyols was enhanced as the concentration of the solutes increased. There was no linear relationship between heat resistance and water activity (aw), but for all solutes except glycerol there was a linear relationship between log D65 and concentration (% w/w) of solute. Comparison of D65 at a particular aw or percentage (w/w) solute concentration showed that the value decreased in the order: sucrose > glucose > sorbitol > fructose > glycerol. In glycerol, D65 values were always very much lower than in any other solute. With sucrose–glycerol or sucrose–glucose mixtures, heat resistance depended both on the total concentration (% w/w) of solutes present and also on the aw of the solution.
Loss of Viability and Metabolic Injury of Staphylococcus aureus Resulting from Storage at 5°C
Authors: Jackson H.
Published: March 2008

Summary. A culture of Staphylococcus aureus in trypticase‐soy broth incubated at 5° became increasingly sensitive to mannitol‐salt agar. The sensitivity was affected by the pH value of the suspending medium. On transfer to 37° the culture rapidly regained the ability to form colonies on the selective medium.
The Effect of Phenols and Heterocyclic Bases on Nitrification in Activated Sludges
Authors: Stafford D. A.
Published: March 2008

Summary. Activated sludge receiving ammonium thiocyanate (500 mg/l) was able to nitrify. The rate of ammonia oxidation was decreased when >3 mg/l of phenol (or cresols) was added to the sludge, and at 10 mg/l was inhibited completely. Concentrations of up to 100 mg/l of phenols did not affect nitrite oxidation. The 2‐ and 4‐methyl pyridine derivatives inhibited both ammonia and nitrite oxidation.
Nitrogen Fixation by Marine Photosynthetic Bacteria
Authors: Wynn‐Williams D. D. , Rhodes Muriel E.
Published: March 2008

Summary. Potential nitrogen‐fixing marine photosynthetic bacteria isolated from the coastal waters and sea‐bed sediments of Cardigan Bay and adjoining mud flats, were investigated, using the acetylene reduction technique, to ascertain the magnitude of their contribution of fixed nitrogen to the coastal ecosystem. Aberystwyth harbour and Iceland fjord mud readily yielded Athiorhodaceae, the majority of which consistently reduced acetylene when grown as pure cultures on marine media. Only one such strain was isolated from local seawater, but they were more common in Iceland fjord water. No marine Thiorhodaceae were isolated. It was essential to monitor crude and pure culture systems for ethylene production in the absence of acetylene.
A Medium for Detecting Phenol‐Degrading Bacteria
Authors: Ralston J. R. , Vela G. R.
Published: March 2008

Summary. A rapid test for the identification of phenol‐degrading bacteria was devised using a medium containing phenol as the sole source of carbon and energy. Degradation of phenol in such a medium was assessed by growth and change in pH value. The results obtained are in agreement with those obtained by methods requiring chemical analysis of phenol in spent culture fluid.
Evaluation of the Growth of Salmonellae in Rappaport's Broth and in Muller‐Kauffmann's Tetrathionate Broth
Authors: Vassiliadis P. , Pateraki E. , Papadakis J. , Trichopoulos D.
Published: March 2008

Summary. The behaviour of 70 strains of salmonellae belonging to 44 serotypes in Rappaport's broth and in Muller‐Kauffmann's tetrathionate broth was examined. With an inoculum of 5–25 cells, 5 strains did not grow in Rappaport's medium, 2 multiplied slowly and 63 grew strongly in 24 h. With an inoculum of 100–500 organisms all but one strain grew readily in 24 h. In Muller–Kauffmann's tetrathionate broth inoculated with pure cultures of salmonellae, growth of many strains was markedly inhibited, in the absence of added faeces, at 37° and 43°. This inhibition was more severe with light inocula at 43°. The addition of 0.05% (w/v) of salmonella‐free human faeces to Muller–Kauffmann's tetrathionate broth, did not stimulate growth of salmonellae. In contrast, the addition of 5% (w/v) of human stools to this medium resulted in a heavy growth of the added salmonellae, especially at 43°.
A Simplified Method for Single Carbon Source Tests with Pseudomonas Species
Authors: Rosenthal S. L.
Published: March 2008

Summary. Thirty Pseudomonas strains representing 13 species were tested for the ability to grow with 14 compounds as sole carbon sources in the following manner: paper discs saturated with 10% solutions of the compounds to be tested were placed on pour plates containing the test organism, ammonium ion, buffer and minerals; the plates were incubated at 30° and the areas near the discs were observed for growth. The results agreed well with reported nutritional patterns. Discs stored at 4° could be used for at least 6 months after preparation. This method is suitable for use by laboratories which only occasionally attempt to characterize Pseudomonas spp. since the materials required can either be stored in a way which uses little shelf space or can be made from ordinarily available media components.
The Validity of the Methylene Blue Reduction Test in the Grading of Ice Cream
Authors: Anderson G. E. , Whitehead J. A.
Published: March 2008

Summary. Samples of ice cream from small manufacturers’plant were examined and graded by the Methylene Blue Reduction Test. The effect of the 17 h incubation period on bacterial populations was examined and the resultant increase in numbers was determined with a Coulter Counter. Most of the ice creams examined fell into Grades 1, 2 or 3, but only a small difference in the colony count range between Grade 1 and Grade 2 samples was observed. Sterile ice cream samples were seeded with pure cultures of selected coliforms and the effect on methylene blue grading was determined. It was found that for each grade of ice cream a far higher number of the added pure culture bacteria was required to achieve the same methylene blue reduction as bacteria of the mixed flora already present.
Iodide Oxidation by Pseudomonas iodooxidans
Authors: Gozlan R. S. , Margalith P.
Published: March 2008

Summary. Iodide oxidation was catalysed by a haemoprotein peroxidase system produced by the marine bacterium Pseudomonas iodooxidans. The presence of starch was essential for iodide oxidation, and its influence was not attributable to its indicator properties. The polysaccharides glycogen and cellulose, but not pectin, could substitute for starch in the reaction. Dextrin, maltose and glucose were not effective. No explanation can be given at this stage for the requirement of a high polysaccharide for bacterial iodide oxidation.
Hydration and pH of Microbially Spoiling Beef
Authors: Shelef L. A.
Published: March 2008

Summary. The extract‐release volume (ERV) technique was used to study the relationship between the hydration and pH of ground beef undergoing microbial spoilage at refrigeration temperatures. The ERV of samples of meat at various stages of freshness and spoilage was determined after adjusting their pH values to between 4.5 and 7.0. ERV responded instantly to pH change and, regardless of the microbial quality of the meat, minimum hydration or maximum ERV occurred at pH 5.5. Since most of the decrease in ERV during the spoilage of beef resulted from the increase in hydration of its proteins, it was concluded that the significant correlation noted previously between ERV and the bacterial quality of beef is highly dependent on the increase in pH value of the meat during spoilage.
The Formation, General Characteristics and Production of α‐Amylase in Heterocaryons and Diploids of Aspergillus oryzae
Authors: Thorbek Lene , Eplov P.
Published: March 2008

Summary. Heterocaryons and diploids from Aspergillus oryzae were investigated with respect to nuclear number/conidium and to conidial size. Heterocaryons usually had larger conidia and more nuclei/conidium than diploids and the haploid parent mutants. Diploids contained significantly fewer nuclei/conidium than haploids. However, they could not be distinguished from haploids by measurement of conidial size. The strains were examined for the production of α‐amylase. All auxotrophic mutants produced less α‐amylase than the prototrophic wild type. Heterocaryons gave yields which were intermediate between that of their parent mutants or the same as the best producing parent. Diploids which produced more α‐amylase than the best producing parent strain were synthesized. The highest yield from a diploid was of the same order of magnitude as the yield from the wild type.
A New Medium for the Detection and Enumeration of Clostridium perfringens in Foods
Authors: Handford P. Marion
Published: March 2008

Summary. This paper describes the development and use of a selective diagnostic medium for the detection and enumeration of Clostridium perfringens in foods. The medium gives higher counts of Cl. perfringens and fewer false positives than existing media.
Effect of Formaldehyde on Fungi from Broiler Houses
Authors: Dennis C. , Gaunt H.
Published: March 2008

Summary. A comparison was made of the relative sensitivity to formaldehyde of the predominant fungi isolated from broiler house litter by treating conidia with aqueous solutions of formaldehyde for 45 min at 20–22°. Aspergillus sydowi and A. versicolor were most tolerant of formaldehyde, followed by A. repens, A. flavus, and A. candidus. Least tolerant were Scopulariopsis brevicaulis, A. ruber, A. chevalieri, and Penicillium crustosum. The viability of conidia of selected strains differing in tolerance to formaldehyde and the viability of fungi and bacteria in dust samples collected from commercial broiler houses were tested after exposure to gaseous formaldehyde at 2 p/m (approximate theoretical concentration attained in broiler houses) and 10 p/m (theoretical) (estimated concentration 5 p/m) for 24 h at 20–22° and 65% relative humidity. The viability of the asexual conidia was always < 0.01% whereas with the dust samples only 10 p/m of formaldehyde markedly reduced the viability of all of the microorganisms.
Inhibition of Swarming in Proteus spp. by Tannic Acid
Authors: SMITH D. G.
Published: March 2008

Swarming in all 27 strains of Proteus spp. tested was inhibited by the presence of 0.02% (w/v) tannic acid in the nutrient medium. Cells from colonies on this medium were nearly all short forms but were motile and piliated. The swarm‐inhibition effect was not reversed by the addition of calcium chloride. The growth of other bacterial species was inhibited to varying extents by tannic acid: Gram positive cocci (Micrococcus, Sarcina, and Staphylococcus spp.) were particularly sensitive. The relative resistance of Gram negative bacteria and the swarm‐inhibition of Proteus spp. could be due to binding of tannic acid to proteins in the outer membrane of the cell wall.
Sporulation of Clostridium putrefaciens and the Resistance of the Spores to Heat, γ‐Radiation and Curing Salts
Authors: ROBERTS T. A. , DERRICK CHRISTINE M.
Published: March 2008

Clostridium putrefaciens grew well in most media used routinely for culturing anaerobes, but produced spores only on lactose‐egg yolk agar. The D80° was 8–14 min, z value was 4°–6° and Dγ, 0.16 Mrad. The inhibitory interactions of pH, NaCl, NaNO2 and incubation temperature are described.
Ultrastructural and Chemical Changes in Spores ofBacillus cereusafter Action of Disinfectants
Authors: KULIKOVSKY A. , PANKRATZ H. S. , SADOFF H. L.
Published: March 2008

Spores ofBacillus cereussubjected to 5% NaOH at 50° and 0.25% NaOCl at 20° undergo a 99% loss in viability in 11 and 19.5 min, respectively. Kinetic studies show that the release of Ca2+and dipicolinic acid occur at different rates and that extensive loss of both ribonucleic and deoxyribonucleic acids occur under these conditions of disinfection. Electron micrographic studies reveal a progressive degradation of the spore integuments. Both chemical and ultrastructural observations made in this study lead to the conclusion that the primary lethal effect of either disinfectant is the modification of outer spore coats leading to a disruption of normal permeability barriers.
Selective Media for the Enumeration of Chromobacterium spp. in Soil and Water
Authors: RYALL C. , MOSS M. O.
Published: March 2008

The development of a selective medium for counting Chromobacterium spp. in river water is described. A mixture of sodium deoxycholate and colistin as inhibitors favoured growth and recovery of chromobacteria. Addition of cycloheximide to this medium controlled the growth of fungi when soil samples were examined.
The Design of Fermentation and Biological Assay Procedures for Assessment of Penicillin Production in Populations of Aspergillus nidulans
Authors: MERRICK M. J. , CATEN C. E.
Published: March 2008

The design of shake flask fermentations and biological assay procedures for the assessment of penicillin titres in populations of Aspergillus nidulans strains is described. Consideration of the amount and stage of replication and the arrangement of the culture filtrates on the assay plate led to the adoption of a general procedure where strains are replicated in 2, 3 or 4 flasks, depending upon the precision required. Each flask is tested using only one inhibition zone and the zones for one replicate set of strains are completely randomized on one assay plate. This experimental design does not require a high degree of statistical competence for interpretation of the results and it may be easily adapted to accommodate a variety of experimental sizes or to allow any required level of discrimination between strains to be achieved. The general approach and principles may be applied to many large scale, low precision assays carried out in fermentation research.
Inhibition of Microbial Fermentations by Sorghum Grain and Malt
Authors: WATSON T. G.
Published: March 2008

A birdproof sorghum cultivar studied, contained substances inhibitory to the growth and fermentation of Lactobacillus leichmannii and Saccharomyces cerevisiae. The bacterial inhibitor is located in the pericarp fraction and is probably of a polyphenolic nature. Inhibition is through the energy metabolism of the bacteria and is completely relieved by the tannin complexing agents PVP and Triton X205. The yeast inhibitor occurs only in malted sorghum and is not polyphenolic in nature. Inhibition may be relieved partially by prior conversion of malt suspensions before introduction of the yeast.
Bacteria Associated with the Gills of Salmonid Fishes in Freshwater
Authors: TRUST T. J.
Published: March 2008

The bacteria on the gills of 7 species of freshwater salmonid fishes were examined qualitatively and quantitatively. Both wild and hatchery cultured salmonids were examined. The former were obtained from 12 different locations in British Columbia. Species of Pseudomonas and Cytophaga predominated on both groups of fish. The microflora of the wild fish also contained Aeromonas and members of the Brevibacterium–coryneform–Erysipelothrix group. The microflora of cultured fish was less varied. As many as 106 viable organisms/g wet weight of gill tissue were recovered.
Evaluation of Two Simple Assay Methods for Detecting Antibiotic Residues in Chicken and Pig Muscle
Authors: SMITHER R.
Published: March 2008

Using 2 paper disc assay procedures, Bacillus cereus and Sarcina lutea were challenged with extracts from chicken and pig muscle paste to which various antibiotics had been added. The first method could detect tetracycline, chlortetracycline, oxytetracycline, penicillin, erythromycin, tylosin and virginiamycin at or <1 μg/g of muscle paste, whilst the second method was necessary to detect the remaining 5 antibiotics at this level. Using the first assay procedure, penicillin, zinc bacitracin and the 3 tetracycline compounds could be detected below FAO/WHO maximum permissible levels for meat for human consumption, whilst the second method was necessary to meet requirements for streptomycin, erythromycin and tylosin. Spiramycin could not be detected by either method at the levels permitted by FAO/WHO. The minimum levels of detection obtained for flavomycin, virginiamycin and monensin were 0.2, 0.02 and 0.5–1.0 μg/g, respectively.