bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE RESISTANCE OF TWO STRAINS OF BACTERIUM COLI TYPE I TO DRYING UNDER ATMOSPHERIC CONDITIONS
Authors: GARVIE ELLEN I. 
Published: March 2008

SUMMARY: Suspensions of two strains of Bacterium coli type I were dried as thin films under atmospheric conditions and the numbers of organisms determined before and after drying. Three methods were used to grow the culture; in two the culture was grown in broth and in the other on agar slopes.Strain 28.D.10 was less sensitive than strain NCTC 5934. After culturing in broth NCTC 5934 showed irregular daily fluctuations in sensitivity to drying; 28.D.10 became more sensitive for the first 2–3 weeks and thereafter less sensitive. Suspensions prepared from 18 hr plate cultures were more sensitive than from 24 hr plate cultures; a change from peptone water to Lemco broth for daily culturing slightly decreased the sensitivity to drying. With both strains suspensions prepared from broth cultures were more sensitive than those from agar slopes.Continuous daily culturing of 28.D.10 on a solid medium as compared with broth decreased the sensitivity of suspensions and over a long period the culture appeared to be more stable. When strain NCTC 5934 was grown on a solid medium the suspension was as sensitive to drying as that obtained when broth was used but the daily fluctuation of results appeared to be less.A decrease in the number of cells in the 24 hr broth culture of 28.D.10 coincided in time with an increase in the sensitivity to drying of the suspension prepared from the same culture.
A COMPARISON OF SOME MILK REJECTION TESTS
Authors: JONES G. ELIS , THOMAS S. B. 
Published: March 2008

SUMMARY: Examination of 202 samples of raw milk showed that the combination of a pH paper strip test with a second sorting test (80 or 76% alcohol or rapid acidity) provided a basis to select milk which required a more time‐consuming test before grading accurately.Samples of pasteurized milk at the yellow‐green stage of fluorescence when examined in ultraviolet light did not clot on boiling and possessed long methylene blue reduction times, whereas at the purple stage of fluorescence the samples clotted on boiling and reduced methylene blue almost instantaneously.
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.
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.
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.
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.
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).
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 thiocyanateManometric 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.
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.
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

SUMMARYDuring 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

SUMMARYMatured 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

SUMMARYThe 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

SUMMARYThe 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.