bluuebunny/crossref_metadata_2025 huggingface dataset:
THE BREAKDOWN OF GLUCOSE BY BACILLUS GLYCOLLACTICUS AND THE EFFECT OF AERATION ON FERMENTATION
Authors: TAHA S. M.
Published: March 2008

SUMMARY: In the decomposition of glucose by Bacillus glycollacticus, CO2, 2:3‐butylene glycol, lactic and acetic acids, ethanol and traces of acetylmethylcarbinol were formed. A satisfactory carbon balance was obtained. Aeration played an important rôle affecting the amounts of products formed and the duration of fermentation. The largest yield of 2:3‐butylene glycol obtained was 32.5 mM from 50 mM of glucose.
THE NORMAL FLORA OF THE BOVINE RUMEN II. QUANTITATIVE BACTERIOLOGICAL STUDIES
Authors: WILSON MARION K. , BRIGGS C. A. E.
Published: March 2008

SUMMARY: A simple medium and dilution count technique was evolved for determining the viable count of rumen bacteria. Material from three fistulated cows was examined and the viable population found to vary within the range 107‐1012/g; the most frequently occurring values were 108‐1010/g (94.0% of 350 counts). Observations were made of the homogeneity of rumen contents, of variations in count with time after sampling and between cows, and of variation from day to day, hour to hour, before and after feeding and on different diets. The variations in the viable count, even with gross changes in diet, were never greater than those occurring in a single animal on a fixed diet. Microscopic examinations showed Gram‐positive cocci and rods to be the most frequently occurring types of bacteria, Gram‐negative organisms of the coli‐aerogenes type being present only in low numbers.
THE BACTERIOLOGY OF FARM WATER SUPPLIES: A STUDY OF THE COLONY COUNT IN 72 HOURS AT 22°
Authors: THOMAS S. B. , THOMAS BLODWEN F.
Published: March 2008

SUMMARY: The colony count at 22° of farm water supplies from springs and wells was mainly composed of biochemically inactive, non‐pigmented, Gram‐negative rods. Water from a stream polluted with farmyard sewage showed a similar dominance of Gram‐negative rods, but orange or yellow pigmented colonies were more abundant. There were few 37° positive coli‐aerogenes bacteria in either the farm water supplies or the sewage polluted stream, and Bact. coli type I was rare.

A high proportion of the bacteria from farm water supplies fermented milk in 3 days at 22°; a third developed acid, 15% proteolysis and 6.4% ropiness.

Contamination of pure spring water with surface soil from a heavily grazed pasture resulted in a hundredfold increase in colony count with aerobic sporing rods replacing Gram‐negative rods as the dominant organisms, but coli‐aerogenes bacteria were absent.
OBSERVATIONS ON THE EFFECT OF ADDED HYPOCHLORITE ON THE NUMBERS AND KINDS OF BACTERIA IN MILK
Authors: McKENZIE D. A. , BOOKER ELIZABETH M. K.
Published: March 2008

SUMMARY: In an investigation of the effect of added hypochlorite on the bacterial flora and bacterial numbers of milk no bactericidal action was apparent within 15 min of adding the disinfectant unless at least 500 p/m available chlorine had been added. After 24 hr storage at atmospheric temperature a reduction in numbers was found with 10 p/m available chlorine and this became more pronounced with increased concentrations. Micrococci seemed more susceptible to the bactericidal effect than streptococci, which formed, after 24 hr storage, the predominant residual flora where 250 and 500 p/m available chlorine had been added. Acid production by lactic streptococci was retarded at concentrations greater than 50 p/m available chlorine in a 5 hr incubation period at 30°, but after a 24 hr incubation the decrease in acid production was only apparent when 500 or 1,000 p/m available chlorine was present. Little effect on acid production by lactic streptococci was found when less than 50 p/m available chlorine had been added. The residual chlorine content of rinses of equipment sterilized in hypochlorite solutions was negligible.
THE NORMAL FLORA OF THE BOVINE RUMEN. III. QUANTITATIVE AND QUALITATIVE STUDIES OF RUMEN STREPTOCOCCI
Authors: PERRY K. D. , WILSON MARION K. , NEWLAND L. G. M. , BRIGGS C. A. E.
Published: March 2008

SUMMARY: One hundred and thirty‐three samples of rumen contents were obtained from four fistulated cows receiving various diets. From dilution counts of all the samples 81 strains of streptococci were isolated, the average of 133 streptococcal counts being more than 108 organisms/ml. Much higher counts (109‐1011/ml) were obtained when the cows were receiving grass, whereas the numbers of presumptive lactobacilli in the rumen were low; the reverse applied with concentrate diets, and a reciprocal numerical relationship between streptococci and lactobacilli according to diet is suggested. All the strains of rumen streptococci were identified physiologically as Streptococcus bovis and classified in serological group D by precipitin tests. Agglutination tests with type sera prepared against some of the strains showed the existence of two types of Strep. bovis, one sharing a common type antigen with streptococci of group E.
A DEVICE TO ASSIST IN ESTIMATING SMALL NUMBERS OF BACTERIA IN LIQUIDS
Authors: THIEL C. C. , AKAM D. N.
Published: March 2008

SUMMARY: An apparatus is described which assists the determination of small numbers of micro‐organisms in liquids by enabling volumetric samples to be taken without risk of aerial contamination. Three sets of 5 containers of 5, 50 and 500 ml are mounted in a common vessel, and are filled as part of the sampling process, and one 2,500 ml sample is contained in an inter‐connected flask. The number of containers showing bacterial growth is used in conjunction with probability tables, to estimate the number of bacteria in the liquid.
SULPHIDE PRODUCTION FROM SULPHATE‐ENRICHED SEWAGE SLUDGES
Authors: BUTLIN K. R. , SELWYN SYLVIA C. , WAKERLEY D. S.
Published: March 2008

SUMMARY: Sterilized raw sewage sludge enriched with sulphate and inoculated with pure strains of Desulphovibrio desulphuricans produced negligible sulphide. Unsterilized sludge supplemented with 7% (w/v) CaSO4.2H2O and inoculated with crude cultures of sulphate‐reducing bacteria obtained from sewage yielded 1·0% S2‐ (wt S2‐ produced as H2S/vol. of raw sludge) in 6 months at 30°. By repeated subculture more active cultures developed which produced 1% S2‐ in 7 days and 1·2–1·9% in 28 days. Digested sludge yielded only 0·1% S2‐. In semicontinuous fermentations at 30°, raw sludge without added sulphate produced 20 times its own volume of gas containing 70% CH4 and 30% CO2. When 5% CaSO4.2H2O and an active crude culture of sulphate reducers were added, gas production decreased steadily to zero. There were no differences in pH, temperature and redox potential in sludges producing methane or sulphide. The chief cause of inhibition appeared to be the action of sulphide: 0·02% soluble sulphide (S2‐) totally inhibited methane formation; 0·01% S2‐ initially decreased gas production by one‐quarter but there was a slow recovery to normal, suggesting acclimatization of the methane‐producing organisms to sulphide.

Linked fermentations, in which gas from a methane fermentation swept H2S from a sulphide fermentation, gave a final gas mixture of about 60% CH4, 30% CO2 and 5–10% H2S. The yield of sulphide depended on the rate of sweeping.
THE ENUMERATION OF ESCHERICHIA COLI I IN SEA WATER. A COMPARISON OF COUNTS DETERMINED BY THE ‘MOST PROBABLE NUMBER’ METHOD IN LIQUID MEDIUM WITH DIRECT COUNTS BY THE ROLL‐BOTTLE METHOD
Authors: WOOD P. C.
Published: March 2008

SUMMARY: A comparison of the 15‐tube liquid dilution method for estimating the most probable number of Escherichia coli I in sea water with a direct roll‐bottle count at 44° using a modified MacConkey's agar revealed no significant differences.

The advantages of the roll‐bottle method include greater accuracy, economy of time and materials, speed with which results are obtained and greater range of pollution that may be estimated without diluting the sample.
NUTRITIONAL REQUIREMENTS OF ACETOBACTER SPECIES: INORGANIC AMMONIUM SALTS AS SOURCES OF NITROGEN
Authors: HALL A. N. , HUSAIN I. , TIWARI K. S. , WALKER T. K.
Published: March 2008

SUMMARY: Forty‐six strains of Acetobacter, representing twenty species, have been compared on the basis of their respective abilities to proliferate in two defined inorganic media, in which either glucose or ethanol was the sole source of carbon and energy. Twenty‐three strains, representing eleven species, grew in either inorganic medium when glucose was present and nine of these strains, representing five species, could grow also in either inorganic medium when ethanol was present. The remaining twenty‐three strains, representing eleven species, failed to grow in either medium with either glucose or ethanol. Three organisms grew better with ethanol than with glucose and three were inhibited by ethanol in the presence of glucose.
COAGULASE POSITIVE STAPHYLOCOCCI FROM BULK MILK SUPPLIES LOW IN SOLIDS‐NOT‐FAT
Authors: INNES A. G.
Published: March 2008

SUMMARY: Tests carried out on coagulase positive staphylococci isolated from bulk milk supplies showed a nearly perfect relationship between α‐lysin production and pigment production at 42°. Ninety‐nine per cent of the organisms were classed as pathogenic, while 75% were probably responsible for sub‐clinical conditions in the udder.
A SURVEY OF THE NUMBER AND TYPES OF AEROBIC MESOPHILIC SPORES IN MILK BEFORE AND AFTER COMMERCIAL STERILIZATION
Authors: FRANKLIN J. G. , WILLIAMS D. J. , CLEGG L. F. L.
Published: March 2008

SUMMARY: Milk, before and after commercial sterilization, supplied by ten different sterilizing depôts, was examined over a period of 18 months to determine the aerobic mesophilic spore content. The numbers present in raw bulk tanker milk exhibited a seasonal variation, the counts being higher in winter than in summer. This was not found in sterilized milk. Spore counts in raw milk ranged from 0—700/100 ml and in sterilized milk, with one exception, from 0—1·1/100 ml.

During the last 12 months of the experiment the types of aerobic mesophilic spore forming organisms causing spoilage were isolated and identified, using a simplified method of identification. Eight different species were isolated from raw milk and seven from sterilized milk. The incidence of the different types in raw milk was: B. licheniformis, 62%; B. brevis, 15%; B. subtilis, 7%; others 9% and unidentified, 7%. In sterilized milk this was: B. subtilis, 44%; B. licheniformis, 26%; others, 17% and unidentified, 13%. There was no apparent seasonal variation in types.
A STUDY OF THE DEVELOPMENT OF THE ROOT SURFACE MICROFLORA DURING THE INITIAL STAGES OF PLANT GROWTH
Authors: ROVIRA A. D.
Published: March 2008

SUMMARY: A study of the development of the microfloras on the seeds and roots of tomatoes and oats during germination and subsequent root development showed a rapid selective multiplication on the seed during the initial stages of germination and also on the root almost immediately after emergence. Evidence is presented that further development of the root surface population after the initial high rate of multiplication was dependent on the normal development of the plant.

Direct microscopic observations of the micro‐organisms of the root surfaces showed interesting differences between the roots of tomatoes and oats. In the former, the root hairs of young plants were free from bacteria but in the oats even young root hairs supported large numbers of organisms. In both plants the root tips were invariably free from organisms.
THE USE OF A SELECTIVE MEDIUM FOR THE ENUMERATION OF LACTOBACILLI IN CHEDDAR CHEESE
Authors: MABBITT L. A. , ZIELINSKA M.
Published: March 2008

SUMMARY: The use of a selective solid medium for counting lactobacilli in Cheddar cheese is described. It has proved useful for this purpose, especially in the early period of ripening when large numbers of streptococci render other methods impracticable.

The medium, in a semisolid form, is more sensitive for the detection of heterofermentation in lactobacilli than media previously available. The possibility of using it to count heterofermentative lactobacilli and leuconostocs is discussed.
METHODS FOR THE ISOLATION OF FAECAL STREPTOCOCCI (LANCEFIELD GROUP D) FROM BACON FACTORIES
Authors: BARNES ELLA M.
Published: March 2008

SUMMARY: Two methods have been developed for isolating and enumerating group D faecal streptococci from localities such as bacon factories where they are heavily outnumbered by other organisms. The first depends on presumptive counts in a Lab‐Lemco‐peptone‐glucose broth (pH 6·0) containing 0·1% of thallous acetate with confirmation by streaking on tetrazolium agar. The other method involves direct plating on tetrazolium‐glucose agar (pH 6·0) containing 0·1% of thallous acetate. On the tetrazolium medium differentiation can be made between Streptococcus faecalis and its variants zymogenes and liquefaciens and the other group D organisms, Strep. faecium, Strep. durans and Strep. bovis.
STUDIES OF THE BACTERIAL CONTENT OF WASHED MILK CANS
Authors: GEORGE GWYNETH , ELSON K. , THOMAS S. B.
Published: March 2008

SUMMARY: Colony counts at 30° were greater than 10 times those at 37° in a high proportion of rinses of washed milk cans, the difference being most marked in those containing milk scale, where 58% of the colony counts at 30° exceeded 106/can. A high proportion of the microflora was composed of thermoduric bacteria. Of 895 cultures from the milk scale, 33% were micrococci, 28% corynebacteria, 22% streptococci, and 9% were Gram‐negative rods. Though aerobic sporing rods constituted only 5% of the microflora of the milk scale, they were present in large numbers and unsatisfactorily washed cans probably constitute one of the main sources of these organisms in milk.
FURTHER STUDIES ON THE REPRODUCIBILITY OF EXTINCTION TIME ESTIMATES
Authors: COOK A. M. , WILLS B. A.
Published: March 2008

SUMMARY: Alterations in peptone concentration, pH and time of autoclaving of peptone water resulted in considerable variation in extinction time estimates. The longest extinction times were obtained with the higher peptone concentration, pH 7·0 and the shorter period of autoclaving.
THE GUT FLORA OF THE CHICK. II. THE ESTABLISHMENT OF THE FLORA
Authors: LEV M. , BRIGGS C. A. E.
Published: March 2008

SUMMARY: Viable counts were made in three media of material from the crop, gizzard, duodenum, ileum and caeca of chicks. Groups of birds 2, 4, 7, 10, 13, 16 and 30 days old were studied. The results showed that a balanced gut flora is established one day after feeding. An indication of the actual development of the flora was obtained in chicks 4 hr after feeding. The relationship between the flora at different ages and that in newly‐hatched chicks before feeding is discussed.
THE DETECTION OF PENICILLIN IN MILK
Authors: WHITEHEAD H. R. , COX G. A.
Published: March 2008

SUMMARY: Penicillin may be detected in milk in concentrations of 0·10 u/ml and upwards by its effect on the morphology of a strain of Streptococcus cremoris grown in the milk for 5 hr.
A TAXONOMIST'S VIEW OF THE COLI‐AEROGENES BACTERIA
Authors: COWAN S. T.
Published: March 2008

SUMMARY: Examples are given of different names that might be applied to the same organisms when the scheme of classification is changed. In particular, the classification of the Coli‐Aerogenes (1956) Sub‐Committee of the Society for Applied Bacteriology and the proposed nomenclature are discussed.
THE DETERMINATION OF ESCHERICHIA COLI I IN SEA WATER
Authors: JOHANNESSON J. K. , MARTIN RAIMONNE E.
Published: March 2008

SUMMARY: For the determination of Escherichia coli I in sea water lactose broth frequently gave higher presumptive and confirmed counts than MacConkey's broth. In the presumptive count there were 53 cases where lactose broth gave larger numbers than MacConkey's broth, with 11 equal counts, and only 25 cases with smaller counts (P=0·00137). After confirmation the corresponding numbers of cases were 39, 10 and 27 (P=0·134).

In the samples giving most probable numbers (MPN) of less than 100 E. coli/100 ml lactose broth was superior to MacConkey's broth (P=0·021). At higher MPN values both media were satisfactory, but with highly polluted water MacConkey's broth might give better recoveries due to the suppression of high concentrations of non‐coli‐aerogenes bacteria.

Samples stored for 24 or 48 hr before testing gave higher presumptive recoveries when examined with lactose broth than with MacConkey's broth, the values for P being 0·028 and 0·0027 respectively.

It appears that lactose broth without inhibitory ingredients could be used with advantage in the examination of sea water.
THE PRESERVATION OF BACTERIA BY DRYING ON CELLULOSE AND ALGINATE FIBRES
Authors: ANNEAR D. I.
Published: March 2008

SUMMARY: Suspensions of Salmonella ndolo were dried in vacuo on both cellulose and calcium alginate fibres and recovered without loss. High recoveries were also obtained after the same organism had been dried on cellulose fibres and stored for a period of six months at room temperature.
OBSERVATIONS ON THE ANAEROBES PRESENT IN A CITY WATER SUPPLY, WITH SPECIAL REFERENCE TO CLOSTRIDIUM WELCHII
Authors: WILLIS A. T.
Published: March 2008

SUMMARY: Black colonies 3 mm or more in diameter, which developed in Wilson & Blair's medium inoculated with samples of untreated water from a city water supply, were examined for their anaerobe content by isolation of pure cultures and by subculture in milk. It was shown that the development of such colonies almost always signifies the presence of clostridia, usually Cl. welchii, and that subculture of such a colony into milk gives reliable confirmation of the presence of clostridia in general and of Cl. welchii in particular.

Fifty strains of Cl. welchii isolated from the water supply were examined, but none was found to be of the heat‐resistant food‐poisoning variety described by Hobbs et al. (1953).
METHODS OF ASSESSING THE SPORICIDAL EFFICIENCY OF AN ULTRA‐HIGH‐TEMPERATURE MILK STERILIZING PLANT. III. LABORATORY DETERMINATIONS OF THE HEAT RESISTANCE OF SPORES OF BACILLUS SUBTILIS IN WATER AND IN MILK
Authors: FRANKLIN J. G. , WILLIAMS D. J. , CLEGG L. F. L.
Published: March 2008

SUMMARY: Thermal death curves for spores of Bacillus subtilis 786 have been determined in water and in milk. Generally a non‐logarithmic order of death was observed. Numbers of survivors were lower in milk than in water, suggesting that there may be inhibitory factors in UHT sterilized milk which affect the germination and/or subsequent growth of heated spores.

The thermal death curves for spores suspended in milk yielded Q10 values of about 30 in the range 110–120°. This is higher than the figures previously reported in the literature for R. subtilis spores. Spores of a number of strains of B. subtilis were compared with strain 786 and all gave high Q10 values.

The results obtained in this work have been used to predict the destruction of spores at higher temperatures in a UHT plant (Burton et al. 1958). The calculated values agree well with the results obtained in the plant by Franklin et al. (1958).
THE INCIDENCE AND THERMAL RESISTANCE OF MESOPHILIC SPORES FOUND IN MILK AND RELATED ENVIRONMENTS
Authors: RIDGWAY J. D.
Published: March 2008

SUMMARY: A spore ‘spectrum’ is described of aerobic mesophiles capable of resisting different heat treatments. It is shown that B. licheniformis is the most common spore former found in bulk milk but since its spores are rapidly destroyed at 100°, the more heat resistant B. subtilis is the dominant surviving spore former in commercial sterilized milk. The thermal resistance of strains of B. subtilis and B. licheniformis isolated from different sources has been investigated and the strains of B. subtilis typed according to the behaviour of their spores when heated at 100°. All strains of B. licheniformis were destroyed more rapidly by boiling for 2 min than strains of B. subtilis but only those strains of the latter which showed some degree of heat activation were more resistant than B. licheniformis. The ‘resistant’ and heat activated strains of B. subtilis appear to be sparsely distributed in nature and were only isolated from sterilized milk where the heat treatment applied would tend to eliminate other strains. The spore content of bovine faeces was similar to that in bulk milk and the total spore content varied seasonally, the spore content of faeces being on the average a hundred times greater during indoor feeding than during the period when the cattle were fed outside. A faecal infection of the milk in the ratio of 1:104 would infect the milk with spores at about the same concentration as they are found in bulk raw milk, and it is suggested that bovine faeces could be a primary source of spore formers in milk supplies.
THE USE OF STORED SUSPENSIONS OF ESCHERICHIA COLI I IN THE EVALUATION OF BACTERICIDAL ACTION
Authors: COOK A. M. , WILLS B. A.
Published: March 2008

SUMMARY: Suspensions of Escherichia coli I, consisting of washed cells suspended in a phosphate buffer solution, maintained a higher viability and resistance to phenol than suspensions either of unwashed cells or of washed cells suspended in water. When stored for 5 weeks at room temperature, variations in their extinction times on exposure to aqueous phenol solutions were not significantly greater than variations with suspensions freshly prepared for each determination. Loss of resistance of a stored suspension to phenol, roxenol, lysol and potassium laurate was roughly parallel. Conditions of culture of the bacteria influenced the survival of suspensions, but the results indicated that pronounced differences may only be found in suspensions prepared from young cultures. The use of stored suspensions in the routine evaluation of bactericides is recommended.
VACUUM DRYING OF STEAM STERILIZED DRESSINGS
Authors: PENIKETT E. J. K. , ROWE T. W. , ROBSON EVELYN
Published: March 2008

SUMMARY: The degree of vacuum and time of application needed to dry steam sterilized dressings has been investigated. If the steam supply is dry, and the pressure in the drying stage is reduced to an absolute pressure of 50 mm Hg, dressings will be cool and dry without holding the vacuum, provided they are not damp before sterilization.
THE CONSTRUCTION OF BIOLOGICAL FILM IN A PERCOLATING SEWAGE FILTER
Authors: WARE G. C. , LOVELESS J. E.
Published: March 2008

SUMMARY: On a microscope slide arranged to simulate a percolating sewage filter the sequence of invading organisms was examined and a primary and secondary invader recognised. These organisms form a substratum suitable for fungal growth.
THE EFFECT OF THE TETRACYCLINE COMPOUNDS ON THE STORAGE LIFE AND MICROBIOLOGY OF CHILLED EVISCERATED POULTRY
Authors: BARNES ELLA M. , SHRIMPTON D. H.
Published: March 2008

SUMMARY: Chlortetracycline, oxytetracycline and tetracycline, incorporated at 10 p/m in the ice slush used for cooling, were equally efficient in extending the storage life of eviscerated poultry which was subsequently frozen, thawed and stored at 1°. There was complete correlation between the sensory assessment of ‘off’odour and the total numbers of micro‐organisms present when these were determined by taking bulk samples of skin from the area under the wing and of the surface tissue of the visceral cavity near the vent. Direct microscopical counts confirmed that the latter area was the most heavily contaminated part of the visceral cavity. Non‐pigmented strains of Pseudomonas were the main spoilage organisms of untreated chickens but Achromobacter strains and yeasts were responsible for the spoilage of the chlortetracycline treated chickens. Fluorescence was only observed in spoiled chickens where pigmented strains of Pseudomonas occurred in significant numbers. Spoilage in both control and antibiotic treated poultry was accompanied by a rise in pH in the contaminated muscles, but for various reasons this change could not be used as a direct measure of the extent of the microbial contamination.
MYCOLOGICAL SYNTHESIS OF FAT FROM WHEY. II. COMPARATIVE STUDIES WITH SHAKEN AND STATIONARY CULTURES USING SELECTED MOULDS
Authors: WIX P. , WOODBINE M.
Published: March 2008

SUMMARY: In detailed studies of the growth of Aspergillus ustus, Penicillium oxalicum, P. frequentans and P. notatum in whey with fat production in view, the first two showed the highest lactose utilization and felt weights in shaken cultures while the last two gave as good or better felt yields in stationary cultures.

When A. ustus was grown in shaken culture in whey with and without the addition of 1·14 g/1. of ammonium nitrate, the extra nitrogen led to the production of larger amounts of fat, but P. frequentans did not form additional fat in these circumstances. A. ustus was the best mould; in whey plus ammonium nitrate it utilized up to 96% of the lactose and formed, per litre of whey, about 17 g of mycelial felt containing 13% of protein and 28% of fat.
THE SUITABILITY OF CERTAIN OBLIGATELY ANAEROBIC NONSPOREFORMING ENTERIC BACTERIA, AS PART OF A MORE EXTENDED BACTERIAL ASSOCIATION, AS INDICATORS OF ‘FAECAL CONTAMINATION’OF FOODS
Authors: MOSSEL D. A. A.
Published: March 2008

SUMMARY: The suitability, as indicators of the faecal contamination of foods, of two types of obligately anaerobic nonsporeforming bacteria which are very numerous in faeces, viz. members of the genera Bacteroides and Bifidibacterium, was tested. For the counting of Bacteroides, Beerens’bile‐azide agar (1957) enriched with 10% (v/v) of blood, and incubated in oval cross section tubes, was found useful. Bifidibacterium could be counted very well in Frisell's tomato‐azide agar (1951), incubated in the same way. Both media being not too selective, confirmation of representative numbers of colonies was necessary. After microscopical examination, the biochemical study of properties such as catalase reaction, oxygen tolerance, carbohydrate fermentation and nitrate reduction may be required.

The 3 Bacteroides strains tested died off rather rapidly when present in sterile ice cream under conditions where Enterobacteriaceae and faecal streptococci increased in numbers. Accordingly they were never found in considerable numbers in some 25 samples of food which appeared to contain very high numbers of other bacteria of faecal origin. The 8 Bifidibacterium strains investigated appeared more resistant. However, under conditions permitting growth, they increased less than the Enterobacteriaceae and faecal streptococci; and where the latter did not increase but did survive, the Bifidibacterium decreased in numbers. In line with these findings Bifidibacterium was not even found in numbers of the order of 10/g in the 25 samples of food mentioned above. Neither Bacteroides nor Bifidibacterium can therefore be considered suitable as an indicator of the contamination of foods with bacteria of faecal origin and of the subsequent growth of these bacteria therein.
THE BIOLOGICAL OXIDATION OF SPENT GAS LIQUOR
Authors: PANKHURST EILEEN S.
Published: March 2008

SUMMARY: Mixed cultures of bacteria grown in spent gas liquor readily oxidized phenol, o‐, m‐ and p‐cresol, catechol, 3‐methyl catechol, 4‐methyl catechol, resorcinol, 2‐methyl resorcinol, and 4‐methyl resorcinol. Quinol, pyrogallol and phloroglucinol were more resistant. The optimum temperature was 30° and the best pH range 6·5–7·8. Yeast extract and sterile sewage sludge both increased the rate of growth of organisms in liquor when the inoculum was small. Five phenol oxidizing organisms were isolated in pure culture. Copper in concentrations greater than 1 p/m inhibited both growth and phenol oxidation by one of these.

Mixed cultures grown in an ammonium thiocyanate medium originally inoculated with Thiobacillus thiocyanoxidans oxidized potassium thiocyanate and sodium thiosulphate. Chloride inhibited thiocyanate oxidation in concentrations above 5,000 p/m, although adaptation to 15,000 p/m was possible. Phenol inhibited thiocyanate oxidation in concentrations of 300 p/m or more. Mixed cultures grown on sodium thiosulphate oxidized sodium trithionate and tetrathionate, potassium pentathionate and hexa‐thionate, and potassium and ammonium thiocyanate

Manometric determinations of the 5 day biological oxygen demand of effluents after treatment showed good agreement with the values obtained by the conventional method, the manometric values being usually somewhat higher.
A METHOD FOR COUNTING THE TOTAL BACTERIA IN AMMONIATED HEVEA LATEX SYSTEMS
Authors: TAYSUM D. H.
Published: March 2008

SUMMARY: A method has been developed for obtaining the total count of bacteria in ammoniated Hevea latex systems. This involves ultracentrifugation of latex or latex concentrate diluted in isotonic saline and the modified use of a normal phase contrast microscope to give a dark ground effect. Examples are given of the degree of bacterial contamination of field latex and concentrate. In these inhibitory ammoniated systems the total count may be high even if the viable count is low: in fact, in all the commercial latex concentrates examined the total count exceeded 108 cells/ml. The value of interference and fluorescence microscopy has also been studied.
THE MULTIPLICATION OF COLI‐AEROGENES BACTERIA IN MILK STORED AT 3–5°
Authors: PANES J. J. , THOMAS S. B.
Published: March 2008

SUMMARY: When 108 samples of individual farm milk supplies were held at 3—5° for 72 hr, 35·2% showed increases in coli‐aerogenes organisms of over one‐hundredfold and 10·2% increases of more than one‐thousandfold. The coli‐aerogenes microflora after refrigeration was dominated by Klebsiella cloacae and K. aerogenes I. While some strains of all the coli‐aerogenes types isolated showed growth, though sometimes scanty, on yeast‐dextrose agar in 5 days at 3—5°, the majority of the strains of K. cloacae showed luxuriant growth under these conditions and can be considered as typical facultative psychrophiles of milk.
A NOTE ON THE ENUMERATION OF THERMOPHILIC SULPHATE‐REDUCING BACTERIA (CLOSTRIDIUM NIGRIFICANS)
Authors: BUFTON A. W. J.
Published: March 2008

SUMMARY: The established techniques for counting mesophilic sulphate‐reducing bacteria were inadequate for counting Clostridium nigrificans. Attempts to improve the viable counts by using different reducing agents and by altering the basal medium achieved only limited success.
THE DIFFERENTIATION OF BACTERIAL SPECIES BY PAPER CHROMATOGRAPHY. VII. THE USE OF ELECTRONIC COMPUTATION FOR THE OBJECTIVE ASSESSMENT OF CHROMATOGRAPHIC RESULTS
Authors: CHEESEMAN G. C. , BERRIDGE N. J.
Published: March 2008

SUMMARY: The use of electronic computation in the objective analysis of the chromato‐graphic patterns of 90 strains of heterofermentative lactobacilli is described. The results showed that there was such a spread of properties among the different strains that a division into species was not justifiable.
A NOTE ON THE SOURCE AND IDENTIFICATION OF THE STRAINS OF THERMOPHILIC LACTOBACILLI SUBMITTED TO CHROMATOGRAPHIC ANALYSIS
Authors: Sharpe M. Elisabeth
Published: March 2008

SUMMARY: Acetic acid extracts of 45 strains of L. lactis, 7 of L. leichmannii, 3 of L. delbrueckii and 4 of L. salivarius were subjected to two dimensional paper chromato‐graphy. The patterns are described, and certain groupings and relationships suggested by them are discussed.
THE BACTERIAL CONTENT OF FARM DAIRY EQUIPMENT
Authors: GRIFFITHS D. G. , THOMAS S. B.
Published: March 2008

SUMMARY: The results obtained during the examination of 2,310 advisory rinses of farm dairy equipment by means of colony count on Yeastrel milk agar at 30°, coli‐aerogenes test at 30° and milk spoilage organisms (MSO) test at 22°, are discussed in relation to attainment of proposed satisfactory colony count levels. A much higher proportion of rinses of milking machine clusters gave unsatisfactory results than those of metal equipment. The MSO test (3 days, 22°) was a more sensitive indicator of the presence of milk spoilage organisms than the coli‐aerogenes test, and is recommended for routine use. Results for milking machine clusters sterilized with steam were much better than those for clusters claimed to have been cleansed by chemical methods.
SOME OBSERVATIONS ON BACTERICIDAL PAINT FILMS
Authors: MORRIS E. J. , DARLOW H. M.
Published: March 2008

SUMMARY: A method is described for testing the self‐sterilizing activity of surfaces coated with paints containing bactericidal agents. The most active coating consisted of 10% (w/w) Cetavlon dissolved directly in urea‐formaldehyde:alkyd resin. The recovery of viable organisms from such surfaces infected with Streptococcus faecalis, Staphylococcus aureus, Aerobacter aerogenes and Chromobacterium prodigiosum was less than 10% of that from painted control surfaces after exposure for 1 hr at atmospheric relative humidity of 70% and temperature of 20°. Bacillus subtilis spores were not affected until they became heat‐sensitive. The self‐sterilizing activity was markedly diminished at 40% r.h. and the inclusion of blood in the deposited bacterial particle was then completely protective. Repeated washing in water with gentle rubbing quickly inactivated Cetavlon paint films.
THE SANITATION OF FISH BOXES. I. THE QUANTITATIVE AND QUALITATIVE BACTERIOLOGY OF COMMERCIAL WOODEN FISH BOXES
Authors: SPENCER R.
Published: March 2008

SUMMARY: The cleaning efficiency of hosing wooden market fish boxes with cold water, the usual commercial practice, was very low, even when high pressure jets were used. After washing, the internal surfaces could still carry up to 20 × 106 bacteria/cm2. Even prolonged steaming failed to sterilize the surfaces. Coryneform organisms accounted for over 50% of the total bacterial flora, although these have usually been reported as present in only low proportions on both fresh and spoiling fish. The major subsidiary groups were species of Achromobacter and Pseudomonas, constituting about 18% and 14% of the population respectively. A few micrococci and flavobacteria were also present.

The conditions of counting, i.e. whether roll tubes or Petri dishes were used, whether incubation was at 0°, 20° or 37°, and whether the media were based on sea or tap water, could markedly influence both the magnitude of the count and the proportions of the different types of bacteria which could be isolated.
THE OCCURRENCE OF BACILLUS CEREUS IN MILK AND ON DAIRY EQUIPMENT
Authors: DONOVAN KATHLEEN O.
Published: March 2008

SUMMARY: In a survey of milk obtained from individual farms and creameries, 87% of samples were found to contain fewer than one cell of Bacillus cereus/ml. The remaining 13%, although they all yielded low counts, showed that the organism tended to occur in milk received from particular farms and creameries. On investigating sources of contaminated milk, it was found that the organism was derived chiefly from cans which, after being emptied of milk, had been allowed to stand for a long time before being washed properly and ‘sterilized’. The vegetative cells of B. cereus were shown to form spores readily in thin films of diluted milk, such as may occur in a rinsed can.
A MUCILAGE‐FORMING LACTOBACILLUS SPECIES ISOLATED FROM CIDER. PART II. POLYSACCHARIDE FORMATION
Authors: HUSAIN I. , HALL A. N. , WALKER T. K.
Published: March 2008

SUMMARY: Cultures grown at 25° under an atmosphere of CO2 in a medium containing maltose, inorganic salts and ethanolic extracts of peptone and yeast autolysate produced a polysaccharide, which was isolated and purified. Examination by a variety of chemical and biological methods indicated that it was a dextran of low molecular weight.
SOME STUDIES OF THE COLONY COUNT TECHNIQUE FOR SOIL BACTERIA
Authors: EGDELL J. W. , CUTHBERT W. A. , SCARLETT C. A. , THOMAS S. B. , WESTMACOTT M. H. , BIRD ELIZABETH R. , HARRISON J.
Published: March 2008

SUMMARY: A series of co‐operative experiments was conducted to compare the bacterial colony counts of soil obtained by workers in different laboratories, using soil extract agar and other media for the determinations.

In the earlier experiments it was not possible to obtain a reasonable degree of reproducibility of results between laboratories even when the plating technique was carefully prescribed. By modification and more rigid standardization of the technique closer agreement was obtained in subsequent experiments. It is suggested that when co‐operative investigations are contemplated the participating laboratories should check their technique by the examination of ‘control’ soils.

No evidence could be obtained to support the suggestion that higher colony counts are obtained by the use of soil extract media containing extract prepared from the same soil as the sample tested. The source appears to be immaterial so long as the soil for extract preparation is not of extreme type and has been well manured and cultivated.
THE INCIDENCE OF PATHOGENIC SEROTYPES OF ESCHERICHIA COLI IN PASTEURIZED MILK AND WASHED BOTTLES
Authors: MURRAY J. G.
Published: March 2008

During the period April‐December 1959 some 7,834 samples of pasteurized milk were examined. From the positive presumptive results in MacConkey's broth at 37°, 165 cultures were obtained which fermented lactose at 44°. From 1957 to 1959, 11,400 washed bottles were tested and 694 gave a positive result in MacConkey's broth at 30°; only 12 of these cultures were positive at 44°. None of the strains of E. coli was a pathogenic serotype.
BACTERIAL MULTIPLICATION IN PACKED WILTSHIRE BACON
Authors: INGRAM M.
Published: March 2008

Matured Wiltshire bacon normally carries 105–106 viable bacteria/g when sliced, predominantly salt tolerant micrococci and lactobacilli.

Kept at 15°, the numbers rose in 4 days to 107–108/g, the flora remaining generally similar in nature and with higher counts at 20° than at 37°. The situation then stabilized; there was a slow decline in organoleptic quality, but nothing unusual occurred in two weeks. Kept at 37°, similar numbers were reached after 1 day, and the nature of the flora changed rapidly, counts at 37° much exceeding those at 20°. Organoleptic deterioration was marked after 2 days and the bacon was unacceptable after 4 days. These changes occurred whether the bacon was packed in air or in 5% oxygen, the oxygen being all consumed in 4 days or less according to temperature. Apparently, if the bacon is kept at too high a temperature for its normal psychrophilic (20° optimum) flora, this is replaced by a mesophilic (37° optimum) flora. It appears that pathogenic staphylococci might be present in this mesophilic flora. A high proportion of isolates proved to be phosphatase positive, or 44° positive; and some had both these properties. Though all, so far, have been coagulase negative, there is no evident reason why pathogenic types should not occur.
THE EFFECT OF ENVIRONMENTAL CONDITIONS ON THE VIABILITY AND GROWTH OF BACTERIA DAMAGED BY PHENOLS
Authors: JACOBS S. E. , HARRIS N. D.
Published: March 2008

The effects of various environmental conditions on the viability and growth of normal Escherichia coli and Staphylococcus aureus cells, and of cells of these species which had been damaged by exposure to phenol, o‐cresol and p‐chloro‐m‐cresol, have been examined.

With normal cells none of the conditions tried had any effect on the initial counts, but sometimes, more often with Staph. aureus, the bulk of growth eventually obtained in broth media was larger, especially when the medium had been made with pyridine extracted peptone, or when it had been treated with 0·1% of Norit charcoal or 0·02% of FeCl3.

In contrast, damaged cells of both species were very sensitive to their environment. At room temperature, 0·1% of Norit added to tap water adsorbed more than 80% of the cells and the initial count was increased. Nevertheless the cells died thereafter. Damaged cells inoculated into broth also died, but when Norit was present both the rate and the extent of death were markedly reduced, though few cells were adsorbed. The addition of FeCl3 (0·02 or 0·03%) had no effect. At 37° damaged cells died faster than at room temperature, but the protective effect of Norit was still evident. In nephelometric studies of cultures growing in Norit treated broth the times to turbidity were shorter than those of control cultures in untreated broth, but broth treated with FeCl3 often gave longer times than the controls.

In a comparison of broths prepared with peptone and/or Lab‐Lemco which had been extracted with pyridine to remove suspected toxic substances, the initial counts of treated cells were highest when only the peptone had been extracted. With media containing extracted Lab‐Lemco, or with both ingredients extracted, the counts were smaller but were still generally higher than in normal broth. The results of nephelometric studies were consonant with these findings: broths prepared with extracted ingredients generally gave shorter turbidity times than normal broth, especially with E. coli.

The addition to broth of cations, especially Mg2+ (10–3 M), favoured the survival of damaged E. coli but did not influence that of Staph. aureus. But with both species, five times that concentration of Mg2+ was as effective as 0·1% of Norit, which was shown to adsorb lead, tin, copper, zinc, silver and cobalt from broth.

Temperatures above 37° were unfavourable to the survival of damaged cells of both species, 44° often being completely inhibitory for Staph. aureus, but this effect was not due to traces of phenol in the inoculum. At 25° damaged E. coli recovered less well than at 30° and 37°, but damaged Staph. aureus did better at 25° and 30° than at 37°.
THE ASSESSMENT OF THE ACTIVITIES OF SURFACE ACTIVE AGENTS FOR USE IN THE CATERING INDUSTRY
Authors: HOBBS BETTY C. , EMBERLEY N. , PRYOR HELEN M. , SMITH MURIEL E.
Published: March 2008

The cleaning and bactericidal efficiencies of a number of detergents were estimated by laboratory tests, the techniques of which are described. Field trials with some of the detergents in a small and a large canteen gave results similar to those obtained in the laboratory. The ability of Salmonella paratyphi B to survive and grow after inoculation into samples of used dish water obtained from a small canteen was demonstrated.
THE EFFECT OF LOW TEMPERATURES ON THE INACTIVATION BY IONIZING RADIATIONS OF CLOSTRIDIUM BOTULINUM SPORES IN MEAT
Authors: INGRAM M. , THORNLEY MARGARET J.
Published: March 2008

The effect of temperature on the inactivation of Clostridium botulinum spores has been studied in minced pork meat irradiated with 2 MeV electrons and gamma rays. When electrons were used, differences in survival after 1 Mrad at 18°, 0° and — 75° were small and were significant only when temperatures of 0° and 18° were compared, a slightly higher survival being obtained at 0°. The effects at temperatures of 0° and —75° were further compared, using a range of gamma ray doses, and regression lines were calculated for the inactivations. From these, ‘sterilizing doses’, i.e. those which would give a survivor level of 10‐12, were calculated, together with their 95% confidence limits. The errors involved in this type of estimate are discussed: it is concluded that there is no evidence of a significant difference in the computed sterilizing doses at 0° and at —75°.
THE EFFECT OF CHLORTETRACYCLINE ON EVISCERATED TURKEYS COMMERCIALLY PROCESSED IN GREAT BRITAIN
Authors: WALKER ELIZABETH A. , TAYLOR J. H. , DAVIS J. G.
Published: March 2008

Ten turkeys, weighing approximately 10 lb, of known history were processed, bisected, randomly distributed between two groups and cooled for 4 hr in water and ice. One group was treated with 10 p/m of chlortetracycline, then all the half carcases were stored at 3°. The treatment with chlortetracycline significantly delayed the onset of spoilage. Bacterial counts of 106 organisms/cm2 of skin were obtained with the control halves on the 7th day and on the treated halves on the 14th day. The development of ‘off’ odours was delayed from 10·1 to 22·2 days. In a second experiment twenty 10 lb turkeys from a similar source and of similar history were processed and treated as described above. Immediately after treatment they were frozen for 19 weeks, thawed, and stored at 3°. These were not examined microbiologically but sensory examination showed that the treatment with chlortetracycline extended the storage life from 7·7 to 10·3 days.
THE SANITATION OF FISH BOXES. III. A COMPARISON OF PLASTIC COATED AND UNCOATED WOODEN BOXES
Authors: SPENCER R.
Published: March 2008

In comparisons of the extents to which new plastic coated and uncoated commercial wooden fish boxes became contaminated when filled with fish, and of the efficiencies of various methods of cleaning them, it was established that the coated boxes were less contaminated before cleaning and were generally cleaned more efficiently by the various methods examined. Scrubbing was essential for uncoated boxes, but hosing with cold water was reasonably satisfactory for coated boxes. The sanitizers and detergents in the concentrations used did not materially enhance the cleaning effect of water alone. There was some evidence that during the experiment a build up of bacteria occurred on coated boxes cleaned by methods which did not involve scrubbing or hosing with a solution of a quaternary ammonium compound.
THE EFFECT OF WATER HARDNESS ON THE GROWTH OF PSEUDOMONAS AERUGINOSA IN METAL CUTTING FLUIDS
Authors: FEISAL E. V. , BENNETT E. O.
Published: March 2008

An investigation of the effect of the salts found in hard water on the growth of Pseudomonas aeruginosa in metal cutting fluids is reported. It was found that hard water and the salts found in hard water stimulate the growth of this organism in the two products employed in the study.
AN EPIDEMIC AMONG INFANTS CAUSED BY SALMONELLA MUENCHEN
Authors: SILVERSTOLPE L. , PLAZIKOWSKI U. , KJELLANDER J. , VAHLNE G.
Published: March 2008

An account is given of a Salmonella muenchen epidemic among infants which was disseminated through an industrially produced and marketed cereal preparation for infant consumption. The epidemic continued for 6 months and was distributed over the whole country. The total number of cases was 110, of which the 62 primary cases were infants under the age of 2 years who were being bottle fed. The duration of excretion of bacteria was studied for both primary and secondary cases grouped according to age. The bacteriological examinations carried out support the view that a small number of Salm. muenchen cells is sufficient to give rise to illness in infants. With the low degree of infection of the cereal powder it proved difficult with the usual technique of cultivation to show the presence of salmonellae and this technique was therefore modified.
INVESTIGATIONS ON THE USE OF THE ROLL TUBE METHOD FOR COUNTING ESCHERICHIA COLI I IN WATER
Authors: PRETORIUS W. A.
Published: March 2008

The roll tube method was used for the enumeration of Escherichia coli I in water and was found to be subject to less variation than the accepted method. Different media were compared and it was found that MacConkey's broth containing 3% of agar gave the best results. Pre‐incubation at 37% for 2 hr improved the selectivity and gave higher colony counts.
THE BACTERIOLOGY OF ICE CREAM STORED IN DOMESTIC REFRIGERATORS
Authors: SEAMAN A. , SMITH KATHLEEN N. , WOODBINE M.
Published: March 2008

Retail blocks of ice cream from three manufacturers were stored for 4 weeks in domestic refrigerators set at ‘normal’ and ‘lowest’ temperatures. Samples from the surface of each block were taken at intervals of a week for one month and were tested by colony counts at 30° and at refrigerator temperature. Samples of the bulk of each block were examined by colony counts and methylene blue reduction tests. There were few bacteria in the standard ice cream and these did not increase in number during the storage period. The dye reduction time of one product was slightly shorter after the sample had been stored; the rest remained unchanged. The reduction time of the sample containing strawberry flavouring and colouring was shorter than that of the corresponding vanilla ice cream and decreased more rapidly. ‘Dairy’ ice cream contained more bacteria than the standard types and had a very much shorter initial reduction time. The only effect of storage of this ice cream was a slight reduction in bacterial numbers. Storage for a month induced surface hardening which made the ice cream unpalatable, but there was no bacterial increase and it was concluded that domestic storage of ice cream does not increase the bacterial load.