bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE SOFT‐ROT BACTERIA OF THE COLI‐AEROGENES GROUP
Authors: TAYLOR C. B. 
Published: March 2008

Summary:The indole, methyl‐red, Voges‐Proskauer and citrate reactions, and the pectate gel‐liquefying, gelatin‐liquefying and lactose‐fermenting properties of nineteen cultures of soft‐rot bacteria have been determined. The cultures included organisms labelled Bacterium carotovorum, Boat, aroideae and Bact. phytophthorum. Their M.R. and V.‐P. reactions and ability to grow in citrate medium are not constant within the group. It is recommended that these organisms should be grouped primarily on the exclusive characteristics of soft‐rot production and pectate gel liquefaction and that they should not be included in the classification of the coli‐aerogenes bacteria proposed by the Society for Applied Bacteriology except in the form of an appendix.Attention has been paid to a comparison of M.R. and V.‐P. reactions in O'Meara's fumarate medium and in the usual glucose‐phosphate broth. Though many more positive V.‐P. reactions are obtained in the fumarate medium, its exclusive use as a diagnostic test medium is not recommended, as it is so highly favourable to the accumulation of acetoin that it makes the test of less value as a means of differentiation.
A NOTE ON THE USE OF DEHYDRATED MILK AGAR FOR BACTERIAL COUNTS ON RAW AND DRIED MILKS
Authors: HIGGINBOTTOM CONSTANCE 
Published: March 2008

SUMMARY: The bacterial colony count of raw milk and of milk powder using milk agar prepared from a proprietary brand of the dehydrated medium has been compared with that obtained using the fresh medium prepared in the laboratory.No significant difference was found in 17 milks which were examined using the roll‐tube technique and 8 replicates/medium but in a second series of 32 milks the plate count (3 replicates/medium) was significantly lower on the reconstituted than on the fresh medium.Some milk powders gave a much lower plate count on the reconstituted medium, due to the inability of the latter to support adequate growth of Streptococcus thermophilus.
SPORULATING ANAEROBES ON ENGLISH FLAX
Authors: HELLINGER ESTHER 
Published: March 2008

Summary:A microaerophilic plectridium identified as Clostridium pectinovorum, and Cl. butyricum, were the major sporulating organisms found on English flax. Both these organisms were non‐pectolytic and unable to ret flax. An orange pigmented anaerobe, identified as Cl. aurantibutyricum, was found as a minor organism, occurring on some samples only. This organism was remarkably pectolytic and an active retting agent. Bacillus polymyxa, which attacks pectin and is a moderately active retting agent in aerobic and anaerobic rets, was occasionally found. Cl. tertium, which has been reported on English flax and in flax rets, and is regarded as an active retting agent in aerated and non‐aerated rets, proved to be non‐pectolytic and showed no retting ability. It was identical with Cl. pectinovorum.
OBSERVATIONS ON THE DISINFECTION OF HOSPITAL BLANKETS WITH QUATERNARY AMMONIUM COMPOUNDS DURING LAUNDERING
Authors: STEINGOLD L. , WOOD J. H. F. , FINCH W. E. 
Published: March 2008

Summary:A method of estimating the bacterial contamination of blankets by using a hair drier to blow filtered air through a fixed portion of a blanket on to an agar plate is described. Results obtained before and after various laundering treatments show evidence of adsorption of quaternary ammonium compounds from solution by blankets and the persistent antibacterial effect of this over several weeks against moist bacteria. It is suggested that the incorporation of these substances in the laundering technique would be a valuable contribution towards the elimination of hospital cross‐infection.
THE CHEMOTHERAPY OF RAT LEPROSY
Authors: CROSHAW BETTY 
Published: March 2008

Summary:Various types of experimental infections with Mycobacterium lepraemurium, have been tried to assess their value in selecting drugs for use in human leprosy. Intraperitoneal infection of albino mice was selected as the most promising ‘screening’test. Of the drugs tested using this method only iso‐nicotinic acid hydrazide had any significant effect.
MARINE BACTERIA OF CARDIGAN BAY. II. BACTERIA IN ROCK POOLS
Authors: HUDLESTON MABYN 
Published: March 2008

SUMMARY: Two pools of different characteristics were examined for bacterial content, marine and alien. Comparative monthly counts showed little consistency over the sampling periods and no definite seasonal variation. Temperature, pH and light had little direct influence. Chromogenic strains were few. Most marine bacteria were small Gram‐negative rods; a high proportion liquefied gelatin, but other biochemical reactions were weak.The amount of dissolved oxygen increased with exposure of the pools but decreased in a third pool devoid of visible flora and fauna. All three pools showed a marked increase in marine bacterial content during intertidal exposure. The coli‐aerogenes organisms content was low and, as in the case of soil and fresh water, the strains showed no definite seasonal variation.
SURVIVAL OF BACTERIUM COLI TYPE I AND STREPTOCOCCUS FAECALIS IN SOIL
Authors: CUTHBERT W. A. , PANES J. J. , HILL E. C. 
Published: March 2008

SUMMARY: Differences have been noted in the numbers of excretal organisms isolated from water supplies coming from gathering grounds with soils of different types. Those from acid moorlands normally contained smaller numbers of Bact. coli type I than those from limestone areas, although the numbers of animals present in the areas were approximately the same.The technique is described for a study of the effect of soils from these areas on the survival of excretal organisms. Incubation of samples of the soils after inoculation with Bact. coli type I and with Strep. faecalis has shown that both organisms will persist in the limestone soils for several weeks but die out in a few days in acid peat soils. When chalk is added to the acid soils both organisms were able to persist for several months. It is suggested that survival is largely governed by pH.
A QUANTITATIVE METHOD FOR ASSESSING THE EFFECT OF DISINFECTANTS AND CLEANING AGENTS ON BACTERIA DEPOSITED ON SURFACES
Authors: HIRSCH A. , MURAS ROSEMARY E. 
Published: March 2008

SUMMARY: A test has been developed for evaluating disinfectant action on surfaces, which relies on the pH response of Strep. faecalis, since with this organism the pH of a buffered broth at the end of incubation depends on the weight of the inoculum, i.e. the numbers of organisms which survive.The organisms are deposited as a wet film on the surface of small strips of tinned mild steel, which are dried and treated with the disinfectant. The strips are finally placed in tubes of media and, after incubation, the pH is measured.The standardization of the different variables of the test are described. The condition of the test organism is particularly important: at the time the films are dried it must be in its stationary phase of growth, when the cells are homogeneous and more resistant to disinfectant action than during the logarithmic phase.Incubation is terminated when the control tubes containing strips which had no disinfectant treatment have pH values averaging 5.50. Under these conditions, with hypochlorite a linear response over the range of 0–6 p/m available chlorine is generally obtained. Chlorine may therefore be used as a standard for comparison with other disinfectants.As an example, the testing of a quaternary ammonium compound is described.
THE EFFECT OF WATER HARDNESS AND TEMPERATURE ON WATER STERILIZATION BY MIXTURES OF DETERGENTS AND QUATERNARY AMMONIUM COMPOUNDS
Authors: COUSINS CHRISTINA M. , CLEGG L. F. L. 
Published: March 2008

SUMMARY: Six QAC detergent mixtures and the QACs alone were tested for bactericidal efficiency in hard and distilled water, using E. coli as test organism, contact times of 1, 2 and 5 min and temperatures of 5, 10 and 17°.The efficiencies of the unformulated QACs were dissimilar. With all, 200 p/m in hard water was less efficient than 50 p/m in distilled water. The efficiencies of the QAC detergent mixtures were not related to that of the pure QAC, the efficiency of a QAC being increased by one detergent formulation and decreased by another. All materials were least efficient at 5°.
CAUSES OF GREENING OF UNEVISCERATED POULTRY CARCASES DURING STORAGE
Authors: BARNES ELLA M. , SHRIMPTON D. H. 
Published: March 2008

SUMMARY: The greening of uneviscerated poultry carcases stored at 15° is due to the production of hydrogen sulphide following multiplication of bacteria in the gut. The main groups present in the gut after death are faecal streptococci, coli‐aerogenes organisms, lactobacilli and clostridia, but their relative importance in causing greening has not yet been established. The hydrogen sulphide diffuses from the gut into the muscle tissue and there reacts with the haem pigments of blood and muscle to form derivatives which microspectroscopically are indistinguishable from sulphaemoglobin.The delay of greening at lower storage temperatures is consistent with this view; and it is suggested that mechanically plucked birds green more rapidly over the ribs than hand plucked ones because the shaking distributes bacteria from the caecum along the gut.
OBSERVATIONS ON THE MICROFLORA OF MINCED CHICKEN MEAT IRRADIATED WITH 4 MeV CATHODE RAYS
Authors: THORNLEY MARGARET J. 
Published: March 2008

SUMMARY: Experiments are described in which minced chicken meat, packed anaerobically, was irradiated at room temperature and in the frozen state with a wide range of doses of 4 MeV cathode rays. Sterility was achieved in 14 out of 15 samples which had received 2 × 106 rads or more. Doses of 0·5 and 1·0 × 106 rads allowed survival of a few bacteria/g, usually spore formers. Bacterial counts indicated an approximately logarithmic decrease in numbers at lower doses, while freezing reduced the bactericidal effect.The storage life at 5° was prolonged only slightly by doses of 5 × 104 and 10 × 104 rads, and highly variable results were obtained with 17·5 × 104 rads. A dose of 25 × 104 rads, however, increased the storage life very considerably. The types of bacteria present initially, and after irradiation with low doses and storage at 5°, were studied. After storage for 12 days or more various types of nonsporing Gram‐positive rods were predominant in almost all samples, both control and irradiated. Streptococci were also important where irradiation with 17·5 × 104 and 25 × 104 rads was followed by long storage.
TEMPERATURE VARIABILITY WITHIN BACTERIOLOGICAL INCUBATORS
Authors: HOSKING ZENA D. 
Published: March 2008

SUMMARY: Temperature variability within four bacteriological incubators regulated for 30° has been studied using readings taken from the normal thermometers and from others placed on the incubator shelves.During 5‐day incubation periods, differences between readings from individual thermometers and between thermometers on different shelves in the same incubator rarely exceeded 0·5° and 1° respectively. The mean temperature recorded on the top shelf was significantly higher (P <0·05) than that on the bottom shelf for all incubators, and than that indicated by the normal thermometers for two incubators.Colony counts for pasteurized milk were not materially affected by within incubator temperature differences in this experiment nor, at three of the four centres, by removal from the incubators for brief periods for counting after intermediate incubation times.
EXOCELLULAR PRODUCT FORMATION BY MICROORGANISMS IN CONTINUOUS CULTURE. I. PRODUCTION OF 2:3‐BUTANEDIOL BY AEROBACTER AEROGENES IN A SINGLE STAGE PROCESS
Authors: PIRT S. J. , CALLOW D. S. 
Published: March 2008

SUMMARY: A quantitative study of the growth and carbohydrate metabolism of Aerobacter aerogenes in continuous culture with particular reference to 2:3‐butanediol production is described. The effects of varying dilution rate, oxygen uptake rate, pH value, temperature and CO2 pressure were studied.The optimum pH value was 5·0°6·0. The optimum temperature was 35–37° with a dilution rate of 0·2 hr−1. The rate of sugar metabolism was decreased by raising the CO2 pressure.In continuous culture the maximum diol output rate/1. of working volume exceeded the greatest rate reported for batch culture by a factor of three. The maximum diol concentration and yield as a percentage of the theoretical maximum were lower in continuous culture than in batch culture. Reasons for this are given.Some variants of the parent organism were found in continuous cultures but they caused no change in the yield of butanediol. There was no sign of loss of butanediol‐producing ability by any of the cultures, some of which were maintained for 2,000 hr. For the first few generations the rate of production of butanediol actually increased.
A SURFACE FILM METHOD OF EVALUATING QUATERNARY AMMONIUM COMPOUNDS
Authors: WHITT EUNICE W. 
Published: March 2008

SUMMARY: A suspension of bacteria was evenly spread on descaled stainless steel strips and air dried. The strips were put into the QAC solution and after the required period the bactericidal action was stopped by adding a neutralizing agent. The strips were covered with nutrient agar and incubated at 37° for 24 hr to enable the surviving organisms to grow into colonies. On removing the thin layers of agar from the strips the colonies were left adhering to the metal. They were stained with carbol fuchsin and counted using a dissecting microscope.Using the recommended strength of a QAC‐detergent solution (200 p/m QAC) and an exposure time of 2 min a mortality of at least 99·58% was obtained. The temperature of treatment had little effect on this, though in experiments with added organic matter or lower concentrations of QAC the temperature was important.
THE HEAT RESISTANCE OF ESCHERICHIA COLI CELLS FROM CULTURES OF DIFFERENT AGES
Authors: LEMCKE RUTH M. , WHITE HELEN R. 
Published: March 2008

SUMMARY: From the mortality curves of Escherichia coli cells heated at 55° in Ringer's solution both Decimal Reduction Times (DRTs) and 99–9% mortality times were obtained. In terms of these measures of heat resistance, cells harvested from broth cultures 0–8 hr old were more susceptible than those from more mature cultures. The time of commencement and the approximate duration of the logarithmic phase of growth of the organism in broth were determined from growth curves, and it was observed that the heat resistance was minimal during that phase.Death rates were not always uniform for the whole of a given population. Particularly among young cultures, a period of rapid death was frequently followed by the slower death of a relatively small number of survivors. In one instance only was an initial period of slow death followed by one of more rapid death.
THE BACTERIOLOGY OF THE ROOT REGION OF THE OAT PLANT GROWN UNDER CONTROLLED POT CULTURE CONDITIONS
Authors: LOUW H. A. , WEBLEY D. M. 
Published: March 2008

SUMMARY: The bacteriology of the root region of oat plants grown under controlled conditions has been studied by means of improved techniques for separate estimation of the microfloras of the rhizosphere soil and of the root surface. The plate count of bacteria in the root region increased during the growing period of the plants; superphosphate produced a greater increase, which was probably due to increased plant growth, as no such effect was observed in uncropped soil.The numbers of acid producing and dicalcium phosphate dissolving bacteria were increased in the root region, but the latter were not preferentially stimulated. Dressings of superphosphate and dicalcium phosphate also did not preferentially stimulate either group. No evidence was obtained, by the plate method used, of the presence of organisms capable of dissolving variscite, strengite, or gafsa rock phosphate, although the plants showed appreciable response to gafsa rock phosphate.
COMPARISONS OF DIFFERENT MEDIA FOR COUNTING SUGAR TOLERANT YEASTS IN CONCENTRATED ORANGE JUICE
Authors: INGRAM M. 
Published: March 2008

SUMMARY: To select and count the sugar tolerant yeasts which ferment sixfold concentrated orange juice, a high sugar agar medium was developed which contains 50% of glucose, 1% of citric acid and 1% of Tryptone; it is incubated for 4–5 days at 25°.The medium has disadvantages: it is troublesome to prepare, and colonies grow slowly and are translucent. These properties result directly' from the high sugar concentration, on which the selective action of the medium depends.Counts on this medium have been compared with those on potato dextrose or nutrient dextrose agars (with 2% and 1% of glucose respectively), with yeasts isolated from fermenting concentrate, in pure culture, and under various practical conditions. As a rule, the counts were virtually the same on the different media; nutrient dextrose agar occasionally failed to record small numbers of these yeasts. If the two low sugar media were acidified to pH 3·5 the counts were reduced.Potato dextrose agar recorded, besides the above yeasts, sugar intolerant yeasts entering from dirty machines or through bad canning practice: nutrient dextrose agar recorded bacteria in addition. The difference between parallel plating on these media and on the high sugar medium thus yielded useful information about sources of casual contamination.It is suggested that the above would also be largely applicable to other sugar‐rich concentrates of not less than 50° Brix.
THE VALUE OF THE ASSOCIATION ESCHERICHIEAE‐GROUP D STREPTOCOCCI IN THE DIAGNOSIS OF CONTAMINATION IN FOODS
Authors: BUTTIAUX R. 
Published: March 2008

SUMMARY: The tests for faecal contamination in foods, based on ‘indicator species’, should be reconsidered for the following reasons. First, in Europe, Escherichia coli is regarded as a specific index of such contamination; but, apparently through the use of antibiotics, the proportion of human faeces containing Klebsiella has risen from 5.2% in 1947 to 48.4% in 1956–7. Moreover, E. coli and other coli‐aerogenes organisms may be absent from the gut of certain animals, notably the pig. Second, while the usual methods of counting coli‐aerogenes bacteria do not permit the isolation of strains which ferment lactose slowly or not at all (i.e. paracolons), these occur in 35.6% of samples of human faeces. Further, the recommended methods of detecting such strains are not wholly satisfactory. Third, the origin of the coli‐aerogenes bacteria is uncertain.It is thus necessary to consider other organisms which normally inhabit the intestinal tract of humans and other animals. As to Clostridium perfringens, its source is doubtful, for it may come from faeces or from soil, and many foods contain only soil strains. The group D streptococci, on the other hand, are excellent indicators of faecal contamination. They are constant or frequent in the intestines of man and animals, and often more numerous there than coli‐aerogenes bacteria. Their specificity as an index of faecal contamination is high and their investigation is easy with the selective media now available. Associated with the coli‐aerogenes bacteria, they justify the diagnosis of faecal contamination in a foodstuff.
MICROBIAL SULPHIDE PRODUCTION FROM SULPHATE‐ENRICHED SEWAGE SLUDGE
Authors: BUTLIN K. R. , SELWYN SYLVIA C. , WAKERLEY D. S. 
Published: March 2008

SUMMARYA laboratory process for the microbial production of sulphide from sewage sludge enriched with sulphate has been further developed. Semicontinuous fermentations yielded 0·9–1·0% S2‐ using a 10‐day replacement time (RT) and 0·8% S2‐ with a 5‐day RT. Yields at 37° were slightly higher than at 30°; at 43° and above yields were much lower. A mixture of 70% N2 and 30% CO2 was successfully used as sweeping gas to remove H2S; other proportions of these gases were less efficient. Stripping H2S from the sludge in an external column was as efficient as passing the stripping gas through the bulk of the fermenting sludge.
AN ECOLOGICAL STUDY OF THE COLI‐AEROGENES BACTERIA OF SURFACE SOIL
Authors: THOMAS S. B. , DRUCE R. G. , ELSON K. 
Published: March 2008

SUMMARYThe coli‐aerogenes organisms content, determined by plating on violet red‐bile agar, of surface soil from a polluted site (heavily grazed pasture) often exceeded 104/g at 30° and 103/g at 37°. Escherichia coli I was present but in a small proportion only. High coli‐aerogenes counts were much less frequent in unpolluted soil (enclosed Forestry Plantation), and E. coli I was relatively rare. The classification of 1,917 strains isolated from colonies on VRB agar at 30° and at 37° showed that Klebsiella cloacae was very much the dominant species in both sites when the plates were incubated at 30°, whereas Citrobacter freundii I and K. cloacae were co‐dominant when incubation was at 37°. E. coli II constituted a relatively high proportion of the strains from both sites but, due to the very marked dominance of these three types, E. coli I was rarely isolated by the method employed, even from the polluted soil. The very high incidence of non‐lactose‐fermenters, particularly among the dominant types, was the outstanding characteristic of the strains isolated, even with incubation at 37°. Only 29% formed acid and gas in MacConkey's broth within 2 days at 37°, while 59% formed acid and gas within 5 days at 30° but failed to do so in 2 days at 37°. There was a much higher incidence of coli‐aerogenes organisms in soil from the unpolluted site during summer than during winter, and this is attributed to possible multiplication of 37° negative strains of the more common types.
THE DIFFERENTIATION OF BACTERIAL SPECIES BY PAPER CHROMATOGRAPHY. IX. THE GENUS BACILLUS: A PRELIMINARY INVESTIGATION
Authors: JAYNE‐WILLIAMS D. J. , CHEESEMAN G. C. 
Published: March 2008

SUMMARYA preliminary survey of species of the genus Bacillus has shown that the comparative study of the bacterial amino pool, using paper partition chromatography techniques, shows promise as an aid to differentiation. But special factors, such as sporulation and other growth characteristics, make the use of these techniques more complicated than is the case with some other genera.Seventy‐five mesophilic strains were examined and in general the chromatogram patterns correlated well with the biochemical, morphological and cultural characters. Further, it appears that these chromatographic techniques could be applied with advantage in the study of spore germination, heat activation and sporulation, and of the influence of growth medium, pH, temperature and degree of aeration on the metabolism of micro‐organisms. The taxonomy of the thermophilic sporeformers and of new species would be clarified by chromatographic studies.
FAT SYNTHESIS BY YEASTS. I. A COMPARATIVE ASSESSMENT OF HANSENULA SPECIES
Authors: HOPTON J. W. , WOODBINE M. 
Published: March 2008

SUMMARYA comparative examination of the growth of 15 species of Hansenula in typical ‘fat’ media has been undertaken. Seven species showed a good yield on the basis of sugar consumed and, in terms of fat content, they fell into three broad categories. H. ciferrii and H. saturnus had a fat content (c. 20%) rather lower than that of Rhodotorula gracilis grown under the same conditions; 2 strains of H. anomala had a fat content of about 13%, and H. jadinii, H. angusta and H. subpelliculosa had a relatively low fat content (c. 8%). In a ‘fat’ medium containing urea as principal nitrogen source there was an initial phase during which most of the nitrogen was assimilated, followed by a phase during which most of the fat accretion occurred.