bluuebunny/crossref_metadata_2025 huggingface dataset:
THE PERFORMANCE OF AN EGG YOLK‐TELLURITE MEDIUM IN PRACTICAL USE
Authors: BAIRD‐PARKER A. C.
Published: March 2008

SUMMARY: Observations by seven laboratories that have used egg‐tellurite‐glycine‐pyruvate agar (ETGPA) (Baird‐Parker, 1962) for isolating Staph. aureus from foods are reported and discussed. The results indicate that ETGPA is superior to media currently used for detecting this organism. The main disadvantages of the medium are the similar appearance of Staph. aureus shown by some strains of Proteus vulgaris and the occasional finding of egg yolk nonclearing strains of Staph. aureus.
The Antibiotic Tolerance of Vibrio cholerae
Authors: Naha P. M.
Published: March 2008

Penicillin G, dihydrostreptomycin, chloramphenicol and chlortetracycline inhibited the growth of a strain of Vibrio cholerae in vitro, in that order of increasing effectiveness, except that at low concentrations dihydrostreptomycin was less effective than penicillin G. The amount of growth made in the presence of an antibiotic, relative to that in an antibiotic free control, as judged turbidimetrically, was a linear function of the concentration and the slopes of the regression lines differed significantly.

Strains resistant to each of the four antibiotics were developed. The culture resistant to chlortetracycline was also relatively resistant to the other three antibiotics, but those which resisted the other antibiotics were greatly affected by chlortetracycline. The relationships between relative growth and concentration were not, however, obviously linear.
Observations on Lysogeny in the Plant Pathogens Pseudomonas mors‐prunorum and Ps. syringae
Authors: Garrett Constance M. E. , Crosse J. E.
Published: March 2008

Phages were detected in 23 out of 56 cultures of Ps. mors‐prunorum, the organism causing the bacterial canker of cherry and plum in south‐east England, but not in 9 cultures of Ps. syringae from diseased pear trees. Attempts to free cultures from phage by repeated subculture from single colonies were in most cases unsuccessful, i.e. the majority of them were lysogenic and not carrier strains. This was confirmed for one strain by plating it with a suitable indicator strain, when a ratio of colonies to plaques slightly greater than 1:1 was observed. Lysogeny was encountered more frequently among the cherry than among the plum strains of Ps. mors‐prunorum. In typing experiments with 13 phages isolated from lysogenic cultures, the nonlysogenic cherry strains reacted more frequently than the lysogenic strains. No such relationship was observed among the plum strains, many of the nonlysogenic forms being immune to all the phages. Phage resistance in the cherry strains could be attributed to the presence of an homologous or closely related prophage, but it apparently had a different basis in the plum strains. The results confirmed the dissimilarity in the phage relationships between plum and cherry strains, previously observed with mainly virulent phages isolated from soils.
Salt Tolerance and Nitrate Reduction by Micrococci from Fresh Pork, Curing Pickles and Bacon
Authors: Patterson J. T.
Published: March 2008

The majority of 164 strains of micrococci and staphylococci isolated from fresh pork, curing pickle and maturing bacon were able to grow at 4°. Greater proportions of strains from brine and bacon tolerated high salt concentrations than did strains from pork. Added nitrate seemed to have a protective or stimulative effect, increasing tolerance. The proportion of the strains able to reduce nitrate to nitrite was large; but it decreased with increasing salt concentration and it is doubtful whether these organisms can reduce nitrate in curing pickles under curing conditions. Strains from all three sources survived incubation in high salt broths and curing pickles much better at 2–3° than at 30°, and there is little doubt that many of the original contaminants of the pork sides could survive the curing process.
Studies of Enzyme Changes During Sporulation in Bacillus cereus, Using Starch Gel Electrophoresis
Authors: Baillie Ann , Norris J. R.
Published: March 2008

Starch gel electrophoresis showed that Bacillus cereus esterase and catalase are not single enzymes but multimolecular species and that they undergo changes during sporulation. Heat resistant spore catalase was detected in vegetative cells before mature spores were present.
Some Investigations on the Growth of Dialister pneumosintes
Authors: Chen Chien‐Ching , Cleverdon R. C.
Published: March 2008

A convenient double bottle vessel is described for the culture of strictly anaerobic bacteria. With D. pneumosintes, about 90 mg dry weight of cells accumulated in about 80 h at 37°; in such conditions the generation time as assessed both by decimal dilution counts and by accumulation of deoxyribonucleic acid was about 2 h.
The Value of Phage Sensitivity Tests for the Identification of Phytopathogenic Pseudomonas Spp.
Authors: Billing Eve
Published: March 2008

Summary: To study the value of phage sensitivity tests for the identification of phytopathogenic pseudomonads, 284 isolates from various sources were examined for their sensitivity to 9 phages. Phages came from infected plants (4), meat (2), manure (2) and from a culture of Ps. mors‐prunorum, P27 (1). The main part of the study was concerned with isolates of Ps. syringae from lilac (6), stone fruits (22), pear (46), Ps. mors‐prunorum (17), Ps. phaseolicola (16) and Ps. lachrymans (11), but single isolates of other phytopathogenic Pseudomonas spp. (30) were also examined. Strains of Ps. aeruginosa (5) and pseudomonads from soil, water and chicken meat (151) were included for comparison. Three of the phages 2, 12B and 33 from plant sources showed a high degree of specificity for Ps. phaseolicola, Ps. syringae (pear isolates) and Ps. syringae (lilac isolates), respectively, but in no case was this absolute. Most isolates of the 4 species studied in detail showed characteristic but not specific patterns with phages 12S, 15 and 21. Many of the phytopathogens were sensitive to phage 12S, but pseudomonads from soil, water and chicken meat were not lyzed by this phage. Of this latter group 44% were lyzed by one or more of the phages from meat or manure (14, 15, 20 and 21). Ps. aeruginosa was not lyzed by any of the phages. The ninth phage, P27, lyzed a proportion of Ps. syringae isolates from pear but none of the other pseudomonads tested.

Tests for oxidase, sucrose oxidation, gelatinase and lecithinase activity were found useful in conjunction with lesion tests for screening purposes. Many of the phytopathogens, especially those having affinities with Ps. syringae, were oxidase negative.

From these results and those of other workers it is concluded that phage sensitivity tests can play a useful part in the identification of phytopathogenic pseudomonads, if used in conjunction with other tests. The importance of the host in connection with phage sensitivity patterns is emphasized; also the fact that isolates from a wide geographical area and saprophytes from the vicinity of the host plant need to be examined if an adequate assessment of the value of a phage is to be obtained.
A Method for the Removal from Membrane Filters of Micro‐Organisms Filtered from Water and Air
Authors: Miller E. J.
Published: March 2008

Summary: The micro‐organisms in tap water were quantitatively (99%) retained by Oxoid membrane filters. The trapped organisms were extracted from the membrane filter by a simple washing process using glass beads or a magnetic stirrer. For counts on air, the membrane filter was considerably more efficient than an ammonium alginate filter in trapping bacteria, but both techniques were equally satisfactory for moulds.
Acetate‐Glyoxylate Medium for the Sporulation of Saccharomyces cerevisiae
Authors: Bettelheim K. A. , Gay J. L.
Published: March 2008

Summary: Studies on ascospore formation by Saccharomyces cerevisiae on sodium acetate agar with and without an addition of sodium glyoxylate showed that the rate of ascus formation was increased when glyoxylate was present. The final proportion of asci was not affected but, since cell multiplication (almost threefold) before ascus formation occurred only on the acetate‐glyoxylate medium, on the basis of the number of asci/unit of inoculum the effect of glyoxylate was even more marked. If CO2 was removed from the atmosphere around the cells, sporulation was strongly inhibited when the medium contained only acetate, but there was less inhibition when glyoxylate was present as well. Ascospores formed on the acetate‐glyoxylate medium changed their staining properties after the third day. The majority then stained with safranin but not with malachite green.
The Examination of Foods for Enterobacteriaceae using a Test of the Type Generally Adopted for the Detection of Salmonellae
Authors: Mossel D. A. A. , Visser M. , Cornelissen A. M. R.
Published: March 2008

Summary: In countries that have recently increased their bacteriological inspection of foods, many products have shown considerable improvement in microbiological quality; simultaneously, however, discrepancies between salmonella and coli‐aerogenes tests, especially on dehydrated and frozen foods, have tended to become more frequent. These discrepancies have been eliminated by applying the following measures: incorporating glucose in culture media so as to reveal all Enterobacteriaceae; placing reliance on growth rather than gas formation so as to avoid missing anaerogenic organisms, and, especially, examining quantities of foods commensurate with those used in salmonella tests.

For this purpose a procedure is recommended in which 10 g of well homogenized food are enriched in 100 ml of buffered brilliant green‐bile‐glucose broth, with no attention being paid to gas formation; the enrichment cultures are then streaked on to MacConkey's glucose agar. Single colonies so obtained are tested for fermentative attack on glucose and may be further examined for other characteristics. The same enrichment fluid can be used for the so‐called ‘nonselective pre‐enrichment’ of samples of food containing salmonellae impaired by periods spent in conditions of low water activity, low pH, etc.
Studies on the Dose Requirement for the Radiation Sterilization of Medical Equipment. I. Influence of Suspending Media
Authors: Burt Margaret M. , Ley F. J.
Published: March 2008

Summary: Spores of Bacillus pumilus were air dried from various suspending media on to the surfaces of different materials representative of those used for medical equipment currently being radiation‐sterilized on a commercial scale. The resistance of the spores to gamma radiation was measured (inactivation factor of 1015 at 2·5 Mrads) and compared with that of the spores in liquid suspension under both aerated and anoxic conditions. Neither the nature of the medium nor that of the supporting surface affected radiation resistance except where local anoxic conditions might be expected, i.e. with spores suspended in a grease and with those trapped in a soluble film surface, when a twofold increase was observed.
The Microflora of Steam Sterilized Milking Equipment
Authors: Thomas S. B. , Druce R. G. , King Kay P.
Published: March 2008

Summary: The classification of 1,466 bacteria, isolated on Yeastrel‐milk agar incubated at 30° from 68 rinses of steam sterilized dairy equipment taken at five farms, showed that micrococci were dominant, with corynebacteria and aerobic sporeforming rods frequent, representatives of these three groups constituting 73% of the isolates. The microflora was characterized by the dominance of organisms which were relatively inactive in milk. Typical milk souring organisms such as lactic streptococci and coli‐aerogenes organisms were rarely isolated, but anaerogenic Gram‐negative rods resembling Achromobacter, Pseudomonas and Flavobacterium were not uncommon on milking machine clusters and on a cooling unit. The glass recorder jars contained a relatively high proportion of sporeformers.
Antibiotic Production by Actinomycete Species on Nitrogen‐Deficient Media
Authors: Considine R. G. , Casida L. E.
Published: March 2008

Summary: Actinomycetes isolated from nitrogen deficient Azotobacter plating medium were checked for antibiotic production on nitrogen deficient media and on these media with yeast extract or ammonium sulphate as nitrogen sources. In nitrogen deficient liquid media cobalt, molybdenum and citrate were required for growth and antibiotic formation. Evidence is presented that the antibiotics resulting from growth under these conditions are different from those produced when combined nitrogen is included in the medium, and it is suggested that this is an area for exploration for new antibiotics.
The Effect on Cotton of Steam Sterilization with Pre‐vacuum
Authors: Henry P. S. H.
Published: March 2008

Summary. Cotton samples bleached to different degrees were subjected to 100 cycles of steam sterilization (137° for 3 min—total cycle time 15 min) with double pre‐vacuum and were tested for strength before and after treatment. There was no laundering between cycles. The strength of normally bleached cotton diminished 16% during the 100 cycles. This is only one‐tenth of the damage caused by slower methods of steam sterilization using lower temperatures and gravity displacement of air.
A Simple Test for Differentiating Streptococcus bovis from other Streptococci
Authors: Sims W.
Published: March 2008

Summary. Streptococcus bovis grew in acid media, which are normally inhibitory for this organism, when incubated in an atmosphere containing 5% (v/v) CO2 or if the CO2 produced by the organism itself was prevented from escaping from the media. Since no other streptococcus grew in acid media under these conditions, this finding enables Strep. bovis to be differentiated from other streptococci by a simple test.
Analysis of Multimolecular Enzymes as an Aid to the Identification of Certain Rapidly Growing Mycobacteria, using Starch Gel Electrophoresis
Authors: Cann D. C. , Willox Margaret E.
Published: March 2008

Four species of rapidly growing mycobacteria were shown to have multi‐molecular forms of esterase and catalase. The number and positions of bands of esterases after electrophoresis in starch gel were characteristic for each of the species Mycobacterium phlei, M. smegmatis, M. fortuitum and M. rhodochrous. Strains of these species are readily identified within 4 days by the method. M. smegmatis and M. fortuitum had esterases which were still active after heating at 100° for 10 min.
Growth Inhibition of Staphylococci by Sodium Thiosulphate
Authors: Kayser A. , van der Ploeg G.
Published: March 2008

The addition of sodium thiosulphate to a medium as neutralizer of an iodine antiseptic resulted in unexpected growth inhibition of various strains of staphylococci and micrococci. The minimum growth inhibiting concentration varied with different strains. The inhibitory effect of sodium thiosulphate was more pronounced in media with low pH values than in those with high pH values, and was diminished by the addition of Tween 80. The action was also found to depend on the concentration of l‐cystine in the medium. It is suggested that the use of sodium thiosulphate be avoided in growth media designed to neutralize iodine in disinfection efficiency tests when staphylococci or micrococci are used as test organisms.
A Spot Test for Catechol 2:3‐Oxygenase in Bacteria
Authors: Pankhurst Eileen S.
Published: March 2008

A simple and quickly performed colour test is described, in which organisms containing catechol 2:3‐oxygenase (meta‐pyrocatechase) produce from catechol a yellow coloured intermediate, α‐hydroxymuconic semialdehyde. The yellow colour is produced most consistently, rapidly and intensely by 2–4 day old cultures from 2·7–27 mM solutions of catechol. The purple‐brown colour produced by some organisms is discussed.

Using growth from nutrient agar plates, the test was applied to cultures of 239 Gram negative bacteria; all of the 64 cultures which gave a positive result had been in contact previously with aromatic substrates and many of them could oxidize phenol. The significance of a positive reaction is discussed briefly.
The Effect of Sodium Chloride on Radiation Resistance and Recovery of Irradiated Anaerobic Spores
Authors: Roberts T. A. , Ditchett P. J. , Ingram M.
Published: March 2008

Sodium chloride (3% and 6% w/v) were without effect on the radiation resistance of spores of Clostridium sporogenes and Cl. oedematiens type C. Increasing doses of gamma radiation rendered spores increasingly sensitive to post radiation inhibition by sodium chloride in the plating medium.
Concerning the Differentiation of Bacillus subtilis and Related Species
Authors: Hanáková‐Bauerová Eva , Kocur M. , Martinec T.
Published: March 2008

The results of an investigation involving 45 strains of Bacillus subtilis, 31 strains of B. licheniformis and 29 strains of B. pumilus are reported. The hitherto recognized varieties B. subtilis var. niger and B. subtilis var. aterrimus appear to be only variants of B. subtilis. For a rapid differentiation of B. licheniformis from B. subtilis two tests are recommended—reduction of nitrites and splitting of arginine. The present tests, reduction of nitrate and hydrolysis of starch, are the most suitable for distinguishing between B. pumilus and B. subtilis.
Species Differentiation of Faecal and Nonfaecal Enterococci
Authors: Moussa R. S.
Published: March 2008

A number of the cultural and biochemical criteria of the more resistant enterococci were used collectively to speciate 2,477 enterooocci strains isolated from water, soil, vegetation, sewage and human and animal faeces into 2 major groups: Streptococcus faecalis and S. faecium. Streptococcus faecalis was found to predominate in the human and poultry gut, S. faecium predominated in the livestock gut, while both organisms were about equally demonstrated in water, soil, vegetation and sewage samples.
Nutrition of Coryneform Bacteria from Milk and Dairy Sources
Authors: Jayne‐Williams D. J.
Published: March 2008

Summary. Growth requirements were determined for 112 cultures of coryneform bacteria including strains of Corynebacterium bovis, C. ulcerans and C. lacticum; in general they were quite distinctive. Of 42 C. bovis strains all had an unsaturated fatty acid requirement fulfilled in chemically defined media by Tween 80, and, but for an atypically nonureolytic strain, all utilized ammonia and urea nitrogen. Whereas vitamins were unessential for the majority of C. bovis. 18 strains failed to grow in the absence of nicotinic acid; however, for 11 of these Casamino Acids replaced nicotinic acid in supporting growth. Thirteen C. ulcerans strains from aseptically drawn milk, as well as two Type Culture strains (NCTC 7907 and 7908) from the human throat required amino acid nitrogen sources, nicotinic acid, pantothenate and biotin. Some nutritional heterogeneity was shown by 46 strains collectively described as C. lacticum obtained from market milk, milk products and dairy utensils; nevertheless the nutritional differences between the groups of these strains correlated broadly with other distinguishing properties. A group of 9 markedly caseolytic strains required amino acid nitrogen sources, thiamine and biotin, whereas a second group of 30 strains, some utilizing inorganic nitrogen sources, required thiamine and pantothenate, with or without biotin. The remaining C. lacticum strains together with a number of unidentified strains from similar sources were generally slow growing and had widely differing growth requirements.
Some Observations on Surface Lipids of Virulent and Attenuated Strains of Corynebacterium ovis
Authors: Jolly R. D.
Published: March 2008

Summary. Observations on the growth of virulent and attenuated strains of Corynebacterium ovis on solid and liquid media, together with quantitative differences in the amount of easily extractable lipid from two of these strains, support the hypothesis that surface lipids are concerned with pathogenicity and virulence of C. ovis. Attenuation was not accompanied by loss of a toxic principle contained in the crude lipid.
Factors influencing the Flavour of Cider: the Effect of Fermentation Treatments on Fusel Oil Production
Authors: Pollard A. , Kieser Margaret E. , Beech F. W.
Published: March 2008

Summary. The flavour of cider is due to both nonvolatile and volatile components. Fermentation treatments cause changes in acidity and influence the formation of higher alcohols or fusel oil. Only the latter are discussed in detail. Preliminary results show that temperature and yeast strain are important factors in their production.
Characteristics of English Isolates of Pseudomonas syringae van Hall from Pear
Authors: Baker Lily A. E.
Published: March 2008

Summary. The cultural and biochemical characters of 30 isolates of Pseudomonas syringae from pear are described and compared with isolates of Ps. syringae from other hosts and with a variety of Pseudomonas spp. from plant material.
The Tellurite Reactions of Coagulase Negative Staphylococci and Micrococci
Authors: Alder V. G. , Brown Anne M. , Mitchell R. G.
Published: March 2008

Summary. Methods for determining the tellurite reactions of coagulase negative staphylococci and micrococci have been applied to strains causing urinary tract infections in human patients. The tellurite positive strains were assigned to Micrococcus subgroup 3 and Staphylococcus subgroup VI of the Baird‐Parker (1963) classification.
Comparison of Plant Pathogenic Pseudomonads from Fruit Trees
Authors: Garrett Constance M. E. , Panagopoulos C. G. , Crosse J. E.
Published: March 2008

Summary. The characteristics of 59 pathogenic pseudomonads isolated from stone fruit trees in south east England, 30 from cherry and 29 from plum, were compared with 41 isolates from pear trees in a wide range of biochemical, physiological and lesion tests. Many characteristics were common, but several consistent and stable differences were found between the stone fruit and pear groups, each of which exhibited a high level of homogeneity. The few atypical isolates in each group deviated from the majority in one or two respects only. Ten citrus and 3 lilac isolates were biochemically and physiologically indistinguishable from the pear isolates but had distinctive phage and bacteriocin sensitivities. The stone fruit isolates correspond to Pseudomonas morsprunorum and the pear isolates to Ps. syringae. The relationship between these two ‘species’is discussed.
Occurrence of Phosphate‐dissolving Micro‐organisms in the Rhizosphere of Rice Plants and in Submerged Soils
Authors: Raghu K. , MacRae I. C.
Published: March 2008

Summary. The incidence of phosphate‐dissolving micro‐organisms in two submerged tropical rice soils, and in the rhizosphere of the rice plant growing in one of these soils at different stages of plant development was studied. Large numbers of anaerobic and aerobic phosphate‐dissolving bacteria were found in both soils after 11 weeks of submergence. Phosphate‐dissolving fungi were found in only one of the soils, a latosolic soil. Both anaerobic and aerobic phosphate‐dissolving bacteria were stimulated in the rice rhizosphere. However, the rhizosphere effect was greater in the case of the anaerobic phosphate‐dissolving bacteria. The rhizosphere effect was greatest at the transplanting stage of rice plant growth but declined with age of the plants. The greatest decline in R/S ratio occurred between transplanting and initial tillering.
Sporicidal Properties of Some Halogens
Authors: Cousins Christina M. , Allan Christine D.
Published: March 2008

Summary. Sodium hypochlorite, sodium dichloroisocyanurate, dichlorodimethyl hydantoin, dibromodimethyl hydantoin and an iodophor have been examined for disinfectant activity against spores of Bacillus cereus. Under the test conditions used sodium hypochlorite was the most effective compound and dibromodimethyl hydantoin was least affected by increase in pH from 6.5 to 8; the activity of the iodophor was unaffected in the pH range 2.3–6.5. Bacillus subtilis spores were much more resistant to the disinfectants than were B. cereus spores. The addition of KBr to solutions of sodium dichloroisoyanurate enhanced its activity at pH 9 but not at pH 7 or 8.

Mixtures of 1.5–4% of NaOH with NaOCl (200 p of available chlorine/m) were much more rapidly sporicidal than either NaOH or NaOCl (pH 9 and above) alone.
Lipolytic Micrococci in Pork Fat
Authors: Cantoni C. , Molnar Maria R. , Renon P. , Giolitti G.
Published: March 2008

Summary. The lipolytic activity of Micrococcaceae on pork fat was investigated by their growth in a fat containing medium. Thirty‐three free fatty acids were detected of which 6 had a carbon chain with < 8 atoms, and were not present in the original fat. In addition to the free fatty acids the formation of 15 carbonyl compounds was detected, most of which were identified. The result of these investigations, and their influence on the microflora of dry sausages has been analysed.
A Medium to Suppress the Swarming of Proteus Species
Authors: Alwen J. , Smith D. G.
Published: March 2008

Media containing activated charcoal inhibited the swarming but not the growth of Proteus mirabilis and P. vulgaris. The suppression of swarming depended on the presence of the charcoal in the medium: media pretreated with charcoal gave normal swarming. Charcoal does not interfere with the production of flagella as do some other substances used for the suppression of swarming. Starch and albumin at similar concentrations to the charcoal had no effect on swarming. Charcoal agar does not interfere with the growth of organisms other than Proteus and so facilitates the isolation of organisms contaminated with Proteus spp.
Relationship between Environmental Temperature and Optimum Temperature of Bacteria along a Hot Spring Thermal Gradient
Authors: Brock T. D. , Brock M. Louise
Published: March 2008

The temperature optima of bacteria occurring at various temperatures along the thermal gradient of a hot spring in Yellowstone Park was studied directly in nature by measuring the rate of incorporation in the dark of [14C]glucose or 14CO2. Bacteria found at environmental temperatures over the range 35‐70° were studied. For each temperature, the optimum for glucose and CO2 incorporation was similar to the environmental temperature.
Studies on the Growth of Group D and other Streptococci in Different Media
Authors: Ramadan F. M.
Published: March 2008

Growth obtained from pure cultures of 9 Streptococcus spp. in media containing different added chemicals revealed that thallium acetate was the least harmful to the generation rate of all test species. Sodium azide follows in that respect except for Strep. uberis. Potassium tellurite tends to produce marked reductions in the generation rate of some species and completely inhibits the log phase in others. The tellurite tolerant species include Strep. faecalis var. zymogenes, Strep. faecalis var. liquefaciens, Strep. pyogenes, Strep. agalactiae and Strep. uberis. The tested Strep. faecalis strain demonstrated an inhibition of the log phase at tellurite concentrations between 0.05 and 0.7%. Sensitive species failing to proceed in a log phase of growth in the presence of 0.01% tellurite concentration include Strep. durans, Strep. lactis and Strep. bovis. The highest number of cell recoveries from the sensitive species may be made at 6 h incubation.
Changes in the pH Activity Profile of the Lysine Decarboxylase during Incubation of Escherichia coli
Authors: Cheeseman G. C. , Fuller R.
Published: March 2008

During prolonged incubation of cultures of Escherichia coli there is a change in the pH of optimum activity of the lysine decarboxylase. The change, which occurs after completion of the logarithmic phase of growth but before any loss of viability, is from an optimum activity at pH 4.0‐4.5 in cultures 24 h old to an optimum activity at pH 6.0‐6.5 in cultures 48 h old. Possible explanations for the phenomenon are a change in enzyme characteristics or in permeability of the cell membrane. Differences in the times of onset of these changes in different strains of E. coli result in lysine decarboxylases of apparently different pH optima, depending on the period of incubation.
Some Factors Influencing the Growth and Survival of Root Nodule Bacteria in Peat Culture
Authors: Roughley R. J.
Published: March 2008

The growth and survival in peat culture of Rhizobium spp. from 3 inoculation groups was markedly affected by the gas exchange properties of the container. Complete restriction of aeration caused rapid reduction in numbers after only 1 week. Low moisture contents restricted growth but higher levels up to 60% (on a wet weight basis) favoured survival. Within the range tested the size of the inoculum was unimportant in determining the number of rhizobia in sterilized peat provided sufficient time elapsed for multiplication. Storage temperatures between 4° and 26° affected the rate of growth but not survival of rhizobia in pure culture for periods up to 26 weeks provided moisture was not limiting.
Bacteriological Aspects of the Storage of Gas Underground
Authors: Pankhurst Eileen S.
Published: March 2008

Sands, formation waters, drilling muds and other samples obtained during exploration of potential gas storage fields were examined for sulphate‐reducing and other bacteria. The origins of the organisms found and their relevance to aquifer storage of manufactured or natural gases are discussed.
Incidence of Clostridium botulinum in Bottom Deposits in British Coastal Waters
Authors: Cann D. C. , Wilson Baebaka B. , Hobbs G.
Published: March 2008

Bottom deposits collected from British coastal waters were examined for the presence of Clostridium botulinum. Cl. botulinum type B was demonstrated in 15 of 429 samples examined. Other types of Cl. botulinum were not found.
Factors Affecting Production of Staphylococcal Lipase
Authors: Vadehra D. V. , Harmon L. G.
Published: March 2008

Lipase production by the cells of Staphylococcus aureus is affected by aeration, agitation, age and pH value of the cultures during growth. At 37° the maximum production of both cells and lipase occurred within the pH range 6.5–9.0, with the optimum for cell production at pH 7.5–8.0 and the optimum for lipase production at pH 7.5–9.0. The presence of air was essential for lipase production, and the maximum lipase activity was produced in a culture incubated 5 days with agitation.
The Antagonism of Enterococci on Other Bacteria in Canned Hams
Authors: Kafel S. , Ayres J. C.
Published: March 2008

Enterococci can act antagonistically on selected species of Clostridium, Bacillus and Lactobacillus in a canned ham environment. This phenomenon is a common feature of Streptococcus faecium, Strep, durans and Strep, faecalis. The antibacterial agent elaborated by these enterococci is probably a metabolite that diffuses into the medium or meat and may play a role in the preservation of commercial products.
A Study of Chromobacterium typhiflavum from the Rat
Authors: Lev M. , Alexander R. H. , Sobel H. J.
Published: March 2008

Two strains of an organism possessing unusual morphological features have been isolated from the rat. Aggregations of individual cells into discrete spherical ‘large bodies’ are found. These bodies appear in chain forms. The nature of the matrix binding the cells is not known. Individual young cells are motile by peritrichous flagella, swarm in soft agar and are Gram negative. Sections of cells show a typically Gram negative cell wall and mode of division. The cell surface appears convoluted in the Gram negative manner. Well defined buds continuous with the cell wall have been demonstrated and many cells contain crystalloid and peripheral bodies. The organisms ferment a wide variety of carbohydrates and are aerobic and facultative anaerobes. These organisms appear to fit the description of Chromobacterium typhiflavum; however the ability to form regular aggregates, containing cells distinct from the ‘vegetative’ form, and to form buds would indicate that this organism should be placed in a new genus.
Growth of Mycobacterium rhodochrous on n‐Decane: a New Growth Factor and Emulsifying Agent
Authors: Holdom R. S. , Turner A. G.
Published: March 2008

During the study of the growth of Mycobacterium rhodochrous NCIB 9905 in a minimal medium with n‐decane as the sole carbon source, a growth factor and a hydrocarbon emulsifying factor were discovered. The factors were heat stable, were released from cells by autolysis or by physical disruption and functioned independently of one another. Inoculations of < 107 cells/ml of culture medium routinely failed to grow unless an autoclaved cell suspension or purified extract was added. This growth factor requirement was not satisfied by exogenous trace metals, vitamins, amino acids, intermediates of decane metabolism or Mycobactin, but was satisfied by an extract from cells of an unrelated species growing on n‐decane. The extract of strain 9905 did not satisfy the sideramine requirement of Arthrobacter JG9 and was not associated with ferric ions. Some evidence was obtained suggesting that the growth factor may be of a new type involving the chelation of calcium ions.
Effect of Irradiation Temperature on Inactivation of Clostridium botulinum Toxin Type E by Gamma Rays
Authors: Licciardello J. J. , Ribich C. A. , Goldblith S. A.
Published: March 2008

At an irradiation temperature of 32°F the inactivation curve for Clostridium botulinum type E toxin was characterized by an initial lag for the first 2 Mrad followed by an apparent linear portion represented by a D10 of 2.1 Mrad. The effect of irradiating at temperatures up to 117.5°F was only to shorten or eliminate the initial lag. A synergistic effect of irradiation temperature was indicated at 91.4 and 105.8°F, but at 117.5°F the toxin appeared more radioresistant.
(Symposium on Myxobacteria and Flavobacteria: Paper X). Properties of Some Pectolytic, Yellow pigmented, Gram Negative Bacteria Isolated from Fresh Cauliflowers
Authors: Lund Barbara M.
Published: March 2008

Pectolytic, yellow‐pigmented, Gram negative bacteria formed 3·3% of the organisms isolated at 23° from fresh cauliflowers, and may contribute to deterioration of this vegetable in storage. The bacteria attacked glucose oxidatively in the Hugh & Leifson (1953) test, were nonmotile and oxidase‐positive, conforming to definitions of the genus Flavobacterium. These strains showed differences in morphological and physiological properties from F. pectinovorum NCIB 9059, which has properties resembling those of Cytophaga spp.
The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of Bacillus stearothermophilus
Authors: Cook A. M. , Gilbert R. J.
Published: March 2008

Increasing concentrations (2, 4 and 8% w/v) of sodium chloride in the heating medium progressively reduced the heat resistance of spores of Bacillus stearothermophilus. Storage at 4° in water or in sodium chloride solutions had little effect on viable counts of unheated spores, but with the increase in sodium chloride concentration there was a reduction in the heat activation effect and a small decrease in heat resistance of the spores. Increasing the severity of heat treatment rendered spores increasingly sensitive to sodium chloride in the plating medium.
Effects of Food Intake on Numbers of Salmonellae and Escherichia coli in Rumen and Faeces of Sheep
Authors: Grau F. H. , Brownlie L. E. , Smith M. G.
Published: March 2008

When 107–108Salmonella anatum or Salm. typhimurium were inoculated into the rumen of sheep consuming 1·3 kg of lucerne chaff daily, salmonellae were eliminated from the rumen in 2 days, and could not be detected in the faeces after c. 1 week. During starvation, both Escherichia coli and salmonellae grew in the rumen. Resumption of feeding after starvation for 3 days caused further multiplication of E. coli and salmonellae in the rumen. The organisms were subsequently eliminated with further feeding. Inoculation with as few as 400 salmonellae cells into a starved sheep led to large numbers of salmonellae appearing in the faeces and being excreted in varying numbers for at least 5 weeks after resumption of feeding.
Some Effects on the Rumen Micro‐organisms of Overfeeding a High Barley Ration
Authors: Mann S. O.
Published: March 2008

When the barley ration fed to a heifer was increased from a steady rate of 3 × 1·7 kg/24 h to 10 kg within 7 h, the animal became lethargic and scoured, and rumen movement ceased. These clinical symptoms were accompanied by gross changes in the bacterial flora of the rumen. Lactobacilli increased from 1·3 × 104/ml to 1·96 × 109/ml and comprised 60–65% of the total viable count, displacing the usual ‘barley type organisms’ (bacteroides and Gram negative vibrio types) as the predominant organisms. At the same time rumen lactic acid concentration rose to 912 mg/100 ml and the pH value fell from 5·7 to 4·5. After recovery of the animal and reintroduction of restricted feeding the ration was slowly increased until it reached a daily level approximating to the amount taken during the period of rapid feeding. The ration of a second animal was similarly increased. The animals showed no ill effects; lactobacilli comprised only 0·19 and 1·17%, respectively, of the total viable counts, rumen lactic acid was < 5 mg/100 ml and the rumen pH values were 5·2 and 5·5 for the 2 animals. Bacteria of the genus Bacteroides predominated in both rumina.
The Growth of Salmonella choleraesuis in Various Enrichment Broths
Authors: Chung G. T. , Frost A. J.
Published: March 2008

Salmonella choleraesuis was examined for growth in selenite, tetrathionate, brilliant green‐MacConkey and nutrient broths. Six strains of Salm. choleraesuis and 8 of Salm. choleraesuis var. kunzendorf were used. Selenite and tetrathionate broths failed to allow growth, especially when the inoculum was small. A modified tetrathionate broth in which half the normal amount of iodide was added was similar to nutrient broth, and brilliant green‐MacConkey broth was also highly effective. The number of organisms required to establish growth in selenite broth was 103−105.
Stimulation of Body Defence against Staphylococcus aureus by Norinyl
Authors: Yotis W. W. , Yotis Eleonora
Published: March 2008

The spleens, kidneys and livers of mice that had received intraperitoneal doses of norethindrone and/or mestranol before intravenous injection with virulent Staphylococcus aureus contained fewer viable staphylococci than did the corresponding organs of control mice. Also, fewer hormone treated mice than control animals died during the 4 days after infection. Both groups survived better when penicillin was administered 12 h after infection. Thirteen serotypes of Staph. aureus grew better in sera of control rabbits than in sera of rabbits treated with both hormones. Rabbits treated with either hormone alone yielded sera that suppressed growth of most, but not all, serotypes. Coagulase, phosphatase, gelatinase, anaerobic and aerobic acid production were not affected by prior growth of staphylococci in the presence of hormones, but the haemolysin titres of staphylococci grown with the hormones were lower than those grown without them.
Dried Paper Discs for Serological Identification of Human Mycoplasmas
Authors: Dighero Mabel W. , Bradstreet C. M. Patricia , Andrews B. E.
Published: March 2008

The preparation of antisera to human mycoplasmas and their use when dried on paper discs are described. The discs were tested in 6 diagnostic laboratories in parallel with locally prepared wet discs as controls. In all 138 mycoplasma strains were examined. Wet and dry discs gave essentially identical results in all but 5% of cases. The dried discs had a shelf life of at least 2 years.
Homofermentative Lactobacilli of Ciders including Lactobacillus mali nov. spec.
Authors: Carr J. G. , Davies Patricia A.
Published: March 2008

This paper describes some homofermentative lactobacilli, found in freshly pressed apple juice, which can be divided into two groups. One of these consists of strains identified as Lactobacillus plantarum, of which nearly all can metabolize quinic acid. The other group, which consists mainly of catalase positive bacteria, is composed of strains alike enough to be grouped together but sufficiently different from other lactobacilli to be proposed as Lactobacillus mali nov. spec.
Bacteria Active in the Spoilage of Certain Sea Foods
Authors: Herbert R. A. , Hendrie Margaret S. , Gibson D. M. , Shewan J. M.
Published: March 2008

Spoilage of certain sea foods is caused by the activities of some groups of Gram negative bacteria. The characteristic off odours and flavours of naturally spoiling cod and haddock have been reproduced in blocks of sterile cod muscle by organisms identified as Pseudomonas putida, Ps. fragi, Ps. putrefaciens and other Pseudomonas spp.
Microbiological and Chemical Changes in Lean Wiltshire Bacon During Aerobic Storage
Authors: Gardner G. A.
Published: March 2008

Total microbial growth and chemical changes in aerobically stored bacon lean were found to fall into 2 phases. Phase 1: there was an increase in total microbial load to c. 109/g, during which most of the nitrate was broken down and there was an accumulation of nitrite. Phase 2: the microbial load increased further to c. 1010/g and during this time most of the accumulated nitrite was broken down to unknown products, so that at the end of the experiments most of the nitrate and nitrite had disappeared from the bacon.

The most important types of micro‐organisms isolated from the bacons were Micrococcus, yeasts, Vibrio, Acinetobacter, Alcaligenes and Arthrobacter‐Corynebacterium. The latter 3 types appeared to be associated with phase 2 changes.
The Germicidal Properties of Ozone—Olefin Mixtures
Authors: Druett H. A. , Packman L. P.
Published: March 2008

Summary: The use of the reaction products between ozone and olefins as a germicidal agent for the maintenance of sterility in rooms during the treatment of patients is discussed. The product is effective against vegetative bacteria and viruses but does not attack bacterial spores at low concentrations. It is most active at high humidities and possesses low power of penetration into cloth. It rapidly disappears from a system once generation ceases, without leaving unpleasant residues. Its high efficiency at low concentrations on finely dispersed bacterial aerosols renders it attractive in special situations. The possibility that it may prove carcinogenic after long human exposures in the presence of influenza virus, the difficulties involved in monitoring the concentrations generated and greatly reduced efficiency in dealing with organisms contained in large particles combine to render it unattractive for hospital use.
Sources and Quantities of Yeast Extract for Growth of Rhizobia
Authors: Date R. A.
Published: March 2008

Summary: The growth of 4 strains of rhizobia representing 4 inoculation groups (clover, medic, cowpea‐type and lupin) in liquid medium containing one of 4 commercially available sources of yeast extract (Vegemite, Oxoid powder, Oxoid paste and BBL yeast) was compared at 4 levels of each extract (1, 2, 4 and 8 g/l). Total cell numbers increased with increasing levels of yeast extract, but viable cell numbers were significantly depressed by some yeast sources. For the clover, cowpea‐type and lupin strains strong depressive effects of BBL yeast were recorded at the highest levels, but satisfactory growth was obtained at the lower levels. Oxoid powder depressed viable numbers slightly but Vegemite did not. All yeast sources increased viable cell numbers of the medic strain with increasing levels in the medium. Reasons for these depressive effects and their practical implication are discussed in relation to legume inoculant preparation.
Plant Growth Substances Produced by Micro‐organisms of Soil and Rhizosphere
Authors: Brown Margaret E.
Published: March 2008

Summary: Micro‐organisms isolated from rhizospheres and rhizoplanes of wheat plants, and from root‐free soil, produced growth regulating substances with the properties of gibberellins and indolyl‐3‐acetic acid (IAA). Substances inhibiting extensions of pea plant internodes and lettuce hypocotyls were also produced, especially by bacteria from the root region of seedlings 6 days old. Bacteria producing growth promoting substances were most abundant on roots of older plants. Seedlings grown aseptically with added gibberellic acid (GA3) and IAA, or grown with a soil inoculum, developed similarly and differed in their morphology from those grown aseptically without additives.
Microbiological Sampling of Poultry Carcasses
Authors: Patterson J. T.
Published: March 2008

Summary: The skin contamination of poultry carcasses from 3 different processing plants was found to vary considerably on the 6 different sites sampled. The neck skin and to a less extent the back and near‐vent sites were more heavily contaminated than 2 sites on the leg and 1 under the wing. Significantly (P < 0·001) lower counts were obtained when the organisms present were recovered at 4° than at 15 or 22°. Swabbing of the skin did not give as good recovery as when the skin sample was removed and shaken in a diluent with an abrasive material, but is adequate to indicate contamination where a nondestructive method is essential. When defrosting frozen carcasses, 2 h on the bench gave as good recovery as carcasses defrosted for 4 h.
Heat Resistance of Bacillus subtilis Spores at Various Water Activities
Authors: Härnulv B. G. , Snygg B. G.
Published: March 2008

Summary: The heat resistance of spores of Bacillus subtilis was determined in water vapour and in aqueous solutions of NaCl, LiCl, glucose and glycerol at various water activities. In water vapour and in glycerol solutions, maximal resistance appeared at low, but not zero water activity. In NaCl and glucose solutions only small variations in heat resistance occurred with decreasing water activity although a small increase was observed at the highest concentrations tested. With increasing concentrations of LiCl, heat resistance at first decreased but increased at water activities below 0·5. The possible interaction of compounds controlling water activity and water activity per se on heat resistance is discussed.
The Detection of Clostridium welchii in the Differential Reinforced Clostridial Medium Technique
Authors: Gibbs P. A.
Published: March 2008

Summary. The enumeration of sparse populations of clostridia by a total clostridia count technique in a fluid medium (DRCM) gives small estimates of the numbers of Clostridium welchii. This organism may be readily detected in mixed ‘presumptive total’ clostridia cultures by streaking on lactose‐egg yolk‐milk agar before pasteurizing these cultures. The results of screening poultry carcases and processing plants with this technique are presented and the incidence of Cl. welchii on 3 sites of poultry carcases (breast, vent and neck skin) are compared for 3 processing plants.
A Method for Assessing the Level of Microbial Contamination in Surgical Materials
Authors: Keall A.
Published: March 2008

Summary. A method is described which increases the efficiency of recovery of microorganisms from solid, fibrous and polymer materials. It is suitable for routine assessment of the microbial quality of various medical products.
Combined Effects of Water Activity, pH and Temperature on the Growth and Spoilage Potential of Fungi
Authors: Horner K. J. , Anagnostopoulos G. D.
Published: March 2008

Summary. An arbitrary parameter ‘rejection time’, i.e. the time required for a fungal inoculum to form a 2 mm diam. colony, was used to express the shelf life of jam after unsealing and exposure of the contents to airborne contamination. Individual and combined effects of water activity (aw), pH value and temperature on rejection time of low sugar jam were estimated from the radial growth on agar of colonies of 9 fungi. The decreases in aw (0·94–0·90) and temperature (25–15°) practicable for low sugar jam were more effective in increasing rejection time than the feasible decrease in pH value (3·7–2·9). The interaction between aw and temperature was significant. The effect of the changes in aw, temperature and pH on rejection time was broadly similar for media adjusted by either sucrose or glycerol. At a given aw, moulds were slightly more tolerant of glycerol than sucrose but yeasts, except for the osmophile Saccharomyces rouxii, were markedly more tolerant of glycerol than sucrose.