bluuebunny/crossref_metadata_2025 huggingface dataset:
METHODS OF ASSESSING THE SPORICIDAL EFFICIENCY OF AN ULTRA‐HIGH‐TEMPERATURE MILK STERILIZING PLANT I. EXPERIMENTS WITH SUSPENSIONS OF SPORES IN WATER
Authors: WILLIAMS D. J. , FRANKLIN J. G. , CHAPMAN HELEN R. , CLEGG L. F. L.
Published: March 2008

SUMMARY: A method of assessing the sporicidal efficiency of a UHT milk sterilizing plant operating on water is described. Water heavily contaminated with spores of a strain of Bacillus subtilis was filtered, after treatment in the plant, through membrane filters and the surviving spores estimated by incubation of the membranes in nutrient agar. With this plant a temperature of c. 135° caused a 99·99999% kill of B. subtilis spores. Confirmation of the lethal effects of temperatures above 135° was obtained by passing treated water into 10 gal churns containing sterile concentrated nutrient broth and incubating the churns.
THE INFLUENCE OF CERTAIN MANUFACTURING PROCESSES ON THE STAPHYLOCOCCUS AUREUS CONTENT OF SPRAY‐DRIED MILK
Authors: CROSSLEY E. L. , CAMPLING MYRTLE
Published: March 2008

SUMMARY: Dried milk was prepared from milks inoculated with pure cultures of Staph. aureus, using a small pilot‐type batch vacuum evaporator and spray drier. Vacuum evaporation reduced the numbers of Staph. aureus in most experiments but one strain was capable of multiplication at evaporating temperatures up to about 43°. Above 49° the organisms declined rapidly and at 56° they were eliminated. Residual staphylococci present in the warm concentrated milk feeding the drier increased in some experiments but declined markedly in others. Staphylococci added directly to warm concentrated milk always proliferated. A small proportion of staphylococci survived spray drying, even with high hot air temperatures. Different strains varied in their susceptibility to different stages of the whole process.
COLI‐AEROGENES BACTERIA OF PASTEURIZED MILKS, WITH SPECIAL REFERENCE TO PATHOGENIC SEROTYPES OF ESCHERICHIA COLI
Authors: PAPAVASSILIOU J.
Published: March 2008

SUMMARY: A total of 375 samples of retail pasteurized milk in bottles was examined from January to the end of August 1955, for coli‐aerogenes bacteria and especially for pathogenic serotypes of Escherichia coli. These serotypes were not found, though 101 of the samples contained bacteria of the coli‐aerogenes group. During the summer months, June‐August, the percentage of contaminated samples was about 40% and 10% of the samples contained E. coli I or II. The epidemiological significance of these findings is discussed.
THE ASSESSMENT OF RELATIVE BACTERICIDAL ACTIVITY AMONG CERTAIN PHENOLS BY A PHYSICAL METHOD
Authors: MAURICE P.
Published: March 2008

SUMMARY: The addition of phenol, various alkyl phenols, or CTAB to a suspension of E. coli in distilled water caused the optical density to increase, the change being more marked as the concentration of a given compound was raised. Families of curves of similar shape were obtained with all the compounds when optical density was plotted against time for different concentrations, and figures expressing the activity relative to that of 1·2% phenol were obtained by dividing the concentration which produced the same curve as that concentration of phenol, into 1·2. These figures were very similar to those obtained for the bactericidal effects of the compounds relative to 1·2% phenol, using an ‘end‐point’ method.

The presence of the chlorides of mono‐ and divalent metals at 10−4 M, or of the sulphates of trivalent metals at 10−5 M, did not affect the turbidity reaction, but higher concentrations of monovalent metal salts, e.g. 2 × 10−2 M phosphate buffer (potassium) at pH 6·7, markedly retarded the change due to phenol. That concentration of the buffer also greatly reduced the bactericidal activity of 1·2% phenol. Much of the turbidity increase, however, occurred after all the cells of the suspensions had been killed, with phenol concentrations over 1·0%.
THE PRESERVATION OF PSEUDOMONAS UNDER MINERAL OIL
Authors: RHODES MURIEL E.
Published: March 2008

The use of mineral oil for the preservation of species of Pseudomonas is described. Eighty‐three out of 91 (91·2%) Pseudomonas isolates remained viable for at least 66 months; 156 out of 168 (92·8%) isolates were still living after at least 46 months, and only 12 out of 170 (2·3%) isolates were non‐viable after three years. An explanation is offered for variation in ability to grow and produce acid in chemically defined media containing galactose or sucrose. The ability to hydrolyze tributyrin and to reduce nitrate was stable over 66 months, regardless of whether the stock cultures were maintained under mineral oil or in yeast‐extract peptone broth. However, the ability to digest milk or gelatin was frequently impaired or lost when cultures were maintained in peptone broth, although the mineral oil‐preserved stock cultures remained stable in this respect. Over a nineteen month period six diagnostic biochemical characters of the oil‐covered stock cultures remained stable within the limits of the experimental methods used. Data from the literature and information from other workers reveal that more complex methods of preserving pseudomonads are not particularly advantageous in regard either to viability or stability. The mechanism of the survival of bacteria under mineral oil is discussed. The taxonomic significance of the loss of proteolytic activity by the ‘bench‐broth’ cultures of Pseudomonas spp. is illustrated by a single example.
A POLARLY FLAGELLATED MEMBER OF THE ENTEROBACTERIACEAE
Authors: COOK KATHLEEN A.
Published: March 2008

SUMMARY: An organism which has been frequently isolated from the rhizosphere of plants of Lolium perenne (Perennial Rye‐grass) is described; it has the typical morphology and flagellation of Pseudomonas but the biochemical reactions of Klebsiella.
A CONTINUOUS INFRARED ANALYSER FOR MEASUREMENT OF CO2 IN EFFLUENT AIR FROM BACTERIAL CULTURES
Authors: TELLING R. C. , ELSWORTH R. , EAST D. N.
Published: March 2008

SUMMARY: The report reviews methods of continuous infrared absorption analysis and gives the description and performance of a commercial infrared CO2 analyser. Examples are given of the use of an infrared analyser recorder to measure CO2 in effluent air from deep cultures. This measure of metabolic activity can be used to estimate growth rate. It is particularly useful because results are obtained with little or no measurement lag and without the need to sample the culture fluid itself.
IMPROVEMENTS IN THE DESIGN OF A LABORATORY CULTURE VESSEL
Authors: ELSWORTH R. , CAPELL G. H. , TELLING R. C.
Published: March 2008

SUMMARY: The application of a radial mechanical shaft seal, and other improvements to a 2–3 1. capacity culture vessel, are described.
THE FAILURE OF PHENOL TREATED ESCHERICHIA COLI TO GROW ON MEMBRANE FILTERS
Authors: HARRIS N. D. , RICHARDS J. P.
Published: March 2008

SUMMARY: Counts of Escherichia coli were done on nutrient agar (control), on membrane filters on nutrient agar and on membrane filters on filter paper pads. With untreated bacteria counts were similar under all conditions, though membrane filters on nutrient agar tended to give slightly low counts. Phenol treated bacteria gave much lower counts when membrane filters were used: the mean counts for 3 strains of the test organism with filters on nutrient agar varied from 35–65% of the control, while counts with filters on filter paper pads were somewhat lower, varying from 30–47% of the control. The low counts on membrane filters on filter paper pads were not due to adsorption of phenol by the filters or to a low concentration of nutrients in the growth medium.
YEASTS CAUSING SPOILAGE IN ACETIC ACID PRESERVES
Authors: DAKIN J. C. , DAY PAMELA M.
Published: March 2008

SUMMARY: Forty‐seven cultures of yeasts, isolated from 47 packs of spoiled acetic acid preserves including 11 varieties and originating from nineteen manufacturers, have been identified according to the system of Lodder & Kreger‐van Rij. Forty‐three cultures had the characteristics of Saccharomyces acidifaciens and four those of Pichia membranaefaciens.
THE RAPID IDENTIFICATION OF ESCHERICHIA COLI I BY THE PRODUCTION AT 44° OF BOTH INDOLE AND GAS FROM LACTOSE
Authors: PAPAVASSILIOU J.
Published: March 2008

SUMMARY: The modification of the 44° test proposed by Mackenzie, Taylor & Gilbert (1948) is useful for the rapid identification of Escherichia coli I in water and foods. False positive tests caused by other coli‐aerogenes bacteria, or by their association with other organisms, can be considered rare. Only a few E. coli I fail to produce indole or ferment lactose at 44°, and further confirmation for routine purposes is necessary only when the results at 44° are discordant, e.g. indole positive‐lactose negative or indole negative‐lactose positive.
BACTERIOLOGICAL STUDIES OF IMMERSION CLEANING OF MILKING EQUIPMENT ON COMMERCIAL FARMS
Authors: EGDELL J. W. , LOMAX KATHLEEN L. , ADAMS R. P. , AITKEN MARGARET J.
Published: March 2008

SUMMARY: A study has been made of the immersion cleaning technique as applied on commercial farms. In an initial survey bacteriological results for rinses and swabs of the milking equipment were satisfactory on most farms, but on one farm the results were very disappointing. Further investigations at this farm showed that the poor results were caused partly by sporing bacteria which survived the caustic soda treatment, presumably in the spore state, and partly by non‐sporing organisms, chiefly chromobacteria and micrococci.

These non‐sporing organisms are found in abundance on the surface of dirty wash troughs, and under certain conditions re‐contamination of the milking equipment can occur during the rinsing operation. Suggested modifications to the original immersion cleaning technique include the use of hot water for the before‐milking hypochlorite rinse, brushing the equipment in the after‐milking rinse to remove extraneous dirt, regular cleansing of the wash trough and the monthly cleansing of the basket and bin.
THE NUMBERS AND GROWTH RATES OF THE BACTERIA IN HEVEA LATEX, AMMONIATED FIELD LATEX AND AMMONIATED LATEX CONCENTRATE
Authors: TAYSUM D. H.
Published: March 2008

SUMMARY: The rates of growth of bacteria on Hevea latex systems in the presence and absence of ammonia have been derived from colony count data obtained on a modified Kligler's iron agar medium. For fresh latex, ammoniated field latex, and ammoniated latex concentrate, variations in the bacterial populations encountered are given for a period of about one year's testing, with some data on commercial samples of latex concentrate. Field latex at routine collection contained about 8 × 106 bacteria/ml. This could be reduced by 62% by the use of sterile tapping cups. In the routine latex, the mixed population grew logarithmically after a lag phase of 2·1/2–3 hr. In clean latex the lag phase was extended to 4 hr. On ammoniation to 0.3% (w/w), the population was reduced over about 2 hr, but subsequently logarithmic growth recurred, without a lag phase. On concentration and further ammoniation to 0·7% (w/w), the count dropped still further, levels of 10/ml or less being achieved in clean conditions, but very slow logarithmic growth again occurred with a lag phase preceding it.
THE RELATIONSHIP BETWEEN MAXIMUM OXYGEN SOLUTION RATES IN A BACTERIAL CULTURE AND IN A SODIUM SULPHITE SOLUTION UNDER COMPARABLE AERATION CONDITIONS
Authors: PIRT S. J. , CALLOW D. S.
Published: March 2008

SUMMARY: The maximum possible oxygen solution rates in bacterial cultures with different aeration conditions were appreciably less (0·5°0·7 times) than those in a sodium sulphite solution containing a copper catalyst under the same aeration conditions. Knowledge of the relationship between the maximum oxygen solution rates in a culture and the sulphite solution enables one to predict from the sulphite measurements the aeration conditions required to satisfy the oxygen demand of a culture.
THE EFFECT OF SUPPLEMENTATION OF THE GROWTH MEDIUM WITH YEAST EXTRACT, ON DEHYDROGENASE ACTIVITY OF ESCHERICHIA COLI
Authors: HUGO W. B. , LUND BARBARA M.
Published: March 2008

SUMMARY: Dehydrogenase activities have been determined of washed suspensions of Escherichia coli prepared from cultures grown in a synthetic medium, and in the same medium supplemented with yeast extract, under conditions of controlled aeration. This supplementation resulted in increased activity of enzymes attacking L(+)‐alanine, DL‐serine, formate and succinate, no apparent change in activity of enzymes attacking L(+)‐gmlumate and D(—)‐ribose, and decreased action on D(+)‐glucose, mannitol and lactate. The results are discussed in the light of present knowledge of the metabolism of E. coli.
A STUDY OF SOIL BACTERIA DISSOLVING CERTAIN MINERAL PHOSPHATE FERTILIZERS AND RELATED COMPOUNDS
Authors: LOUW H. A. , WEBLEY D. M.
Published: March 2008

SUMMARY: Over a hundred isolates which produced haloes around their colonies on dilution plates containing calcium carbonate or dicalcium phosphate have been obtained in pure culture from the root region of the oat plant. Of these, more than 50% were pleomorphic, and this group had the highest proportion of isolates which could produce clear zones on agar media containing either calcium carbonate, dicalcium phosphate, tricalcium phosphate, freshly precipitated hydroxyapatite or basic slag. None of the isolates showed dissolving ability on agar media containing gafsa rock phosphate, variscite, strengite or taranakite. However, when an analytical method was used, 82% of the isolates tested proved able to release phosphate from gafsa rock phosphate, though to a much lesser extent than from dicalcium phosphate. None of the isolates tested by this method released phosphate from variscite, strengite or taranakite.

The nature of the organic acids produced from glucose by 26 of the isolates was also investigated. The majority produced mainly lactic acid, but a few also gave an acid with chromatographic properties similar to those of 2‐keto‐gluconic acid.
THE INFLUENCE OF RENNET ON BACTERIOPHAGE INFECTION IN THE CHEESE VAT
Authors: MEANWELL L. J. , THOMPSON NORAH
Published: March 2008

SUMMARY: Early gelling of a lightly phage‐infected culture of lactic streptococci in milk gave protection against phage attack. This protection was necessary only at acidities of less than 0·33% lactic acid (pH 5·36) and depended on the formation of isolated foci of infection in the gel structure.
THE INACTIVATION OF BACILLUS SUBTILIS SPORES IN PENICILLIN BY GAMMA RADIATION
Authors: HILL E. C. , Phillips G. O.
Published: March 2008

SUMMARY: Sodium benzylpenicillin, contaminated with Bacillus subtilis spores by freeze‐drying a suspension of spores in an aqueous penicillin solution (c. 50% w/v), was exposed to gamma radiation and a 70‐tube dilution method was used to determine the surviving spores after various doses. The correlation coefficient between log10 percentage survival and dose was −0.9523. The regression of the former on the latter was calculated and the decimal reduction dose found to be 20.2 × 104 rads. The regression and the decimal reduction dose were similar to those obtained when suspensions of spores in distilled water were irradiated.
MYCOLOGICAL SYNTHESIS OF FAT FROM WHEY. I. PRELIMINARY STUDIES WITH STATIONARY CULTURES
Authors: WIX P. , WOODBINE M.
Published: March 2008

SUMMARY: Forty mould species, 30 of which were from the genera Aspergillus, Penicillium, Fusarium and Mucor, were examined for their ability to utilize the lactose in whey and to produce fat in the mycelium in stationary cultures.

In terms of lactose consumed and weight of mycelial felt produced the most promising species were A. ustus, P. frequentans, P. oxalicum and P. notatum. The first three of these warrant further study as fat producers.
A STUDY OF A GRAM‐POSITIVE COCCUS RESPONSIBLE FOR ROPINESS AND VISCOSITY IN MALT WORT
Authors: HOPTON J. W. , HALL A. N.
Published: March 2008

SUMMARY: A Gram‐positive coccus with the properties typical of pediococci produced a ropy, viscous growth in malt wort. Nutritional studies in the media of Dunn et al. (1947) showed pantothenic acid to be required by the organism but growth occurred in the complete medium only when a trace of malt wort was present. Seven other vitamins tested were not necessary for growth.

In a medium consisting of mineral salts, glucose and alcoholic extracts of peptone and yeast autolysate the organism grew well and the viscosity of the medium increased. Higher viscosities were attained when the buffering capacity of the medium was increased either by raising the concentrations of the alcoholic extracts or by adding sodium acetate. The material responsible for the viscosity was produced in small amounts only and appeared to be a mucopolysaccharide. The only sugar obtained on hydrolysis of this material was glucose.

Fructose, maltose, sucrose and raffinose were all fermented by the organism but only in media containing maltose was the increase in viscosity comparable with that attained in a glucose‐containing medium.
COLI‐AEROGENES BACTERIA IN FARM WATER SUPPLIES
Authors: THOMAS S. B. , HOBSON PHYLLIS M. , DRUCE R. G. , BOWEN D. L. , JONES R. G. , MACKENZIE ELIN , VAUGHAN W. L. R.
Published: March 2008

SUMMARY: A series of 825 cultures of coli‐aerogenes bacteria isolated at 30° and a series of 735 cultures isolated at 37° from 645 samples of farm water supplies were classified according to the recommendations of the Coliform Sub‐Committee of the Society for Applied Bacteriology (Report, 1949). Klebsiella constituted 50% of the cultures isolated at 30°, whereas Escherichia coli I was the dominant type, forming 57%, among the cultures isolated at 37°. It would thus appear that isolation at 30° is as selective for Klebsiella as isolation at 37° is for Escherichia. Coli‐aerogenes organisms, mainly 37° negative strains of Citrobacter freundii I and K. cloacae, were found in waters of high sanitary quality derived from protected springs and wells; but the coli‐aerogenes microflora of polluted water was dominated by E. coli I, which formed 43% of the isolates at 30° and 76% of those at 37°. The results for a series of fortnightly samples from 11 farm water supplies showed a marked seasonal variation in the incidence of different types isolated at 30°; E. coli I formed a higher proportion in summer than in winter, while 37° negative strains of Klebsiella and Citrobacter formed a higher proportion in winter than in summer.
THE MICROBIOLOGICAL EXAMINATION OF BUTTER
Authors: DRUCE R. G. , THOMAS S. B.
Published: March 2008

SUMMARY: Butter made on farms and at creameries was examined microbiologically within 24 hr of production. The overall care exercised in the manufacture of the butter was reflected in the results obtained with the various tests used. Colony counts of psychrophiles, coli‐aerogenes organisms, and yeasts and moulds were the most useful and economical tests for providing information on the standard of hygiene during manufacture, and they gave some indication of the potential keeping quality of the butter. The following satisfactory levels are recommended for creamery butter: psychrophiles <103/g, coli‐aerogenes organisms <10/g and yeasts and moulds <50/g.
COLD‐TOLERANT FERMENTATIVE GRAM‐NEGATIVE ORGANISMS FROM MEAT AND OTHER SOURCES
Authors: EDDY B. P. , KITCHELL A. G.
Published: March 2008

SUMMARY: From various chilled meats, twenty‐eight strains of coli‐aerogenes bacteria and one Aeromonas were isolated which grew well at +1±5° and some at −1±5°. The optimum growth temperature for most of these strains was nearer 37° than 30°. Nine strains (including the Aeromonas) fermented lactose rapidly, the remainder slowly or not at all. All the strains which fermented lactose rapidly with the production of gas gave positive presumptive coli‐aerogenes tests in MacConkey's broth at 30°, but only five were positive at 37°; none was positive at 44°. Because such organisms can attain populations of millions/cm2, they could confuse the interpretation of presumptive coli‐aerogenes tests made on chilled meat.
A STUDY OF THE BACTERIA ASSOCIATED WITH THE ROOTS OF SUBTERRANEAN CLOVER AND WIMMERA RYE‐GRASS
Authors: SPERBER JOAN I. , ROVIRA A. D.
Published: March 2008

SUMMARY: A study of the bacteria from the surfaces of roots of subterranean clover (T. subterraneum L.) and Wimmera rye‐grass (L. rigidum Gaud.) revealed that 21 genera were represented among the isolates from clover and 16 genera among those from rye‐grass. Bacteria showing branched forms predominated and accounted for 63% of the 151 clover isolates and 78% of the 167 grass isolates. Most of these were identified as Arthrobacter, but from clover a significant proportion were Nocardia‐like types. Members of the genera Mycoplana, Micromonospora, Mycobacterium, and Mycococcus were also identified among the branching forms.

Although the soil had been inoculated with effective rhizobia and the clover plants were effectively nodulated only one of the 318 isolates was capable of nodulating subterranean clover. The majority of the isolates were chromogenic and Gram‐negative, produced acid from glucose and ammonia from peptone, were catalase‐positive and grew best aerobically. Approximately half the isolates liquefied gelatin and produced hydrogen sulphide from peptone.
THE EFFECT OF FREEZING AND STORAGE ON THE BACTERIAL FLORA OF PASTEURIZED MILK
Authors: MURRAY J. G. , COEY W. E.
Published: March 2008

SUMMARY: Experiments were designed to determine the effect of freezing and storage on the bacterial population of pasteurized milk. Samples taken on separate occasions sometimes reacted differently to freezing treatment. Significant changes in bacterial numbers occurred after the frozen milk had been stored for 4–5 months at −12°, and this coincided with definite physical changes in the milk. Known numbers of coliaerogenes organisms were added to the pasteurized product in order to study their behaviour when frozen and stored at low temperatures. The counts were significantly lower after storage for 4 months.
THE INVESTMENT VALUE OF CONTINUOUS CULTURE
Authors: ELSWORTH R. , TELLING R. C. , EAST D. N.
Published: March 2008

SUMMARY: Comparisons are given of the output of sorbose from 3 litre cultures of Acetobacter suboxydans grown in a sorbitol medium in batch and continuous culture. An estimate is given of the investment value of a continuous process of sorbose production relative to the batch process.
A TRIPLE SUGAR‐UREA‐IRON MEDIUM FOR THE CONFIRMATION OF SALMONELLA AND THE EXCLUSION OF PROTEUS STRAINS
Authors: STEWART D. J.
Published: March 2008

SUMMARY: A modification of the dulcitol‐lactose‐iron medium of Taylor & Silliker (1958) is proposed. It contains sucrose as well as lactose to aid in detecting slow lactose fermenters and gives simultaneously tests for urea hydrolysis and H2S production. The latter reaction is kept apart from the carbohydrate fermentations and the urea hydrolysis. The surface growth can be used in a test for the deamination of phenylalanine to phenylpyruvic acid.
THE SANITATION OF FISH BOXES. II. THE EFFICIENCY OF VARIOUS SANITIZERS IN THE CLEANING OF COMMERCIAL WOODEN FISH BOXES
Authors: SPENCER R.
Published: March 2008

SUMMARY: An investigation of the effect of various sanitizers, including kinds containing hypo‐chlorite, formaldehyde and quaternary ammonium compounds, alone and with detergents, and of a nonionic detergent alone, on the cleanability by various methods of commercial wooden fish boxes, showed that no major reductions in viable counts greater than 99·9% could be expected; this was due presumably to the high degree of contamination of the box and the porous nature of the wood. Of the materials investigated, hypochlorite solutions containing not less than 1,000 p/m of free chlorine and the quaternary ammonium compounds in 0·1–1% concentrations were most satisfactory. The implications of these investigations, to the fish industry in particular and to the cleanability of wooden surfaces in general, are discussed.
THE AVOIDANCE OF EXCESSIVE SUPERHEATING DURING STEAM STERILIZATION OF DRESSINGS
Authors: KNOX R. , PENIKETT E. J. K. , DUNCAN MARY E.
Published: March 2008

SUMMARY: During the steam sterilization of dressings some degree of superheating occurs. With dressings normally hydrated, that is with about 5% moisture content, the small degree of superheating which occurs is unlikely to be of consequence; but if dressings contain less than 1% of moisture before sterilization, a significant degree of superheating may occur. The use of drums is neither an advantage nor a disadvantage in regulating superheating, which occurs to the same degree whether the air is removed initially by vacuum pump or by downward displacement. The use of a high initial vacuum does not increase the risk of superheating.
EXPERIMENTS ON THE ACCURACY OF SURFACE DROP BACTERIAL COUNTS
Authors: BADGER E. H. M. , PANKHURST EILEEN S.
Published: March 2008

SUMMARY: A statistical experiment has shown that no significant proportion of the errors of determination of bacterial populations by the surface drop method could be attributed to the dropping technique employed. With both pure and mixed cultures the numbers of colonies/drop followed a Poisson distribution very closely.

It is suggested that in order to determine bacterial populations at a consistent level of accuracy a constant number of colonies should be counted rather than a constant number of drops. Whenever it is justified, the confidence limits for the results of counts should be quoted.
FACTORS CONTROLLING THE SPORULATION OF YEASTS. I. THE PRESPORULATION PHASE
Authors: FOWELL R. R. , MOORSE MARGARET E.
Published: March 2008

SUMMARY: Yeasts tend to dissociate into mixtures of cell types with different powers of sporulation; hence single cell isolates are recommended for sporulation studies. The ability of yeasts to produce 4‐spored asci can be improved by single cell selection. Cells from actively fermenting cultures sporulate much better than those grown under aerobic conditions. Sporulating ability depends on fermentation ‘age’, reaching a maximum when 85–90% of the CO2 has been evolved. Carbon dioxide assimilation in the presporulation phase appears essential for maximal sporulation, but complete anaerobiosis in this phase is detrimental to sporulating ability. Malt wort cultures of a baker's yeast have given remarkably constant figures, in successive tests, for sporulation; but some batches of wort have an adverse effect on sporulating ability. The same yeast, grown on Lodder‐Rij's synthetic medium containing 4 or 8% (w/v) of glucose, is capable of 80% sporulation (proportion of cells forming asci) on sodium acetate agar, comparable to that obtainable with malt wort cultures. Sporulation is depressed by excess storage of fat, while storage of glycogen does not affect sporulating ability.
ANTIBIOTIC SUBSTANCES FROM A STRAIN OF BACILLUS SUBTILIS
Authors: PURKAYASTHA M. , NANDI P.
Published: March 2008

SUMMARY: Strain B7 of B. subtilis, isolated from soil collected from the gardens of the Bose Institute, Calcutta, was found to elaborate at least four different antibiotic substances. Fraction I was a brick red amorphous powder with certain resemblances to the bacillomycin group of antibiotics, soluble in alcohols, pyridine, etc., but insoluble in ether, water and acids. It had an ultraviolet absorption maximum at 276 mμ, melted with decomposition at 311°, and was a polypeptide positive to ninhydrin. On hydrolysis 12 amino acids were found. Fraction II was a white amorphous powder soluble in alcohols and ether but insoluble in water and petroleum ether. It melted at 158–162° and was a ninhydrin positive polypeptide composed of 7 amino acids. Fraction III was a yellow amorphous powder soluble in water and acetone, less soluble in ether and practically insoluble in chloroform. It was not a polypeptide. Fraction IV was a yellowish white amorphous powder with solubility characteristics similar to those of fractions I and II. It was a polypeptide composed of 10 amino acids.
A STUDY OF THE EFFECT OF TANNINS ON THE GROWTH OF SULPHATE‐REDUCING BACTERIA
Authors: BOOTH G. H.
Published: March 2008

SUMMARY: The inhibition by tannins of sulphate‐reducing bacteria in pure culture has been shown to be due primarily to the establishment of an unfavourable pH. High concentrations were required to inhibit when the physico‐chemical conditions were otherwise favourable.
THE EFFECT OF CHLORTETRACYCLINE ON EVISCERATED CHILLED CHICKENS COMMERCIALLY PROCESSED IN GREAT BRITAIN
Authors: WALKER ELIZABETH A. , TAYLOR J. H. , DAVIS J. G.
Published: March 2008

Thirty broiler chickens of known weight and history were processed simultaneously under normal conditions in each of three poultry packing stations, visually assessed to be operating at ‘ideal’, ‘good’, and ‘poor’levels of hygiene. The eviscerated carcases were bisected, cooled to 3° in chilled air, and distributed between three treatment groups which were dipped for 30 min in chilled water containing 0, 10 and 20 p/m of chlortetracycline respectively. During storage at 3° for 3 weeks, microbiological and sensory examinations were undertaken. At all levels of hygiene, the application of the antibiotic significantly delayed the onset of spoilage; the differences between the effects of 10 and 20 p/m were small and generally insignificant. Bacterial counts of 106/cm2 of skin were obtained from the controls on the 7th day of storage whereas similar counts on the treated groups were not reached until the 14th day. ‘Off’odours developed in the control groups between the 5th and 7th days and in the treated groups between the 10th and 14th days. The nature of the spoilage flora acquired during processing appeared to be associated with the duration of storage.
THE EFFECT OF CHLORTETRACYCLINE ON EVISCERATED FROZEN CHICKENS COMMERCIALLY PROCESSED IN GREAT BRITAIN
Authors: WALKER ELIZABETH A. , TAYLOR J. H.
Published: March 2008

Twenty broiler chickens of known history were processed, bisected, randomly distributed between two groups and then cooled for 2 hr in water and ice. One group was treated with 10 p/m of chlortetracycline. After wrapping, the carcases were blast frozen and stored, first at —15° for 5 months, and then at 3°. During the latter period sensory examinations were done. Treatment with chlortetracycline delayed the appearance of visible microbial growth from a mean of 6·2 days in the controls to 7·8 days, and the onset of ‘off’ odours was also delayed, from a mean of 6·1 days in the controls to 8·5 days. It appeared that poultry meat which had been frozen and thawed was more highly perishable than fresh chilled poultry meat.
THE RAPID TENTATIVE RECOGNITION OF PSYCHRO‐TROPHIC TYPES AMONG ENTEROBACTERIACEAE ISOLATED FROM FOODS
Authors: MOSSEL D. A. A. , ZWART H.
Published: March 2008

Enterobacteriaceae which can grow at the temperatures prevailing in refrigerated food stores (‘psychrotrophic’Enterobacteriaceae) can be distinguished from strains which cannot develop below 10° because the latter generally grow quickly on nutrient agar at 43°0±1° whereas the former do not. By this test inadequately refrigerated foods can be differentiated from those kept properly refrigerated.
THE USE AND MEANING OF THE TERM ‘PSYCHROPHILIC’
Authors: EDDY B. P.
Published: March 2008

A case is presented for the introduction of the term ‘psychrotrophic’ for bacteria able to grow at 5° or less. The term ‘psychrophilic’ should be used only when a low optimum temperature is implied.
A FLOW REGULATOR FOR AUTOMATIC pH CONTROL
Authors: WRIGHT W. C.
Published: March 2008

A device is described for improving the automatic regulation of pH of cultures of the order of 1 litre in volume by imposing delays between small successive additions of acid or alkali to allow time for mixing.
DEVELOPMENTS IN APPARATUS FOR THE CULTURE OF MICRO‐ORGANISMS: DESIGN FEATURES OF A LABORATORY TWO STAGE CONTINUOUS FLOW CULTURE APPARATUS
Authors: CALLOW D. S. , PIRT S. J.
Published: March 2008

A two stage continuous flow apparatus with a first stage working volume of 2–3 1. and a second stage working volume of 6–14 1. is described.

Each stage has separate controls over the environmental factors; temperature, pH value and nutrient supply; and over foaming.

In the first stage the dilution rate is altered by changing the flow rate; in the second stage the dilution rate is altered by changing the working volume.

The apparatus has proved suitable for the continuous culture of a filamentous mould, which is more exacting from the engineering standpoint than culture of bacteria.
A NOTE ON THE SYSTEMATIC POSITION OF VIBRIO FETUS
Authors: PARK R. W. A.
Published: March 2008

The morphology of Vibrio fetus, and of some nonpathogenic vibrios isolated from cattle, has been compared with that of 5 type cultures of Vibrio spp., including V. cholerae, and the systematic position of these bovine vibrios reviewed. Morphological differences between V. fetus and the nonpathogenic bovine vibrios have been observed. These may be of assistance in their identification.
A STUDY OF ANTIGENS OF THE AEROBIC SPOREFORMING BACTERIA
Authors: NORRIS J. R. , WOLF J.
Published: March 2008

Spore, vegetative O and vegetative H agglutinogens were demonstrated as separate entities in Bacillus species. Spore precipitinogens were distinct from those of the vegetative stage, the latter being associated with the H antigen.

Injection of viable spores into rabbits resulted in the formation of antibodies for the vegetative phase as well as spore antibodies, while injection of autoclaved spores gave rise to spore antibodies only.

Spore agglutinogens varied in their strain specificity, B. cereus and B. megaterium especially showing much subspecies specificity, but the spore precipitinogens showed a high degree of species specificity and could be of considerable taxonomic value. The multiplicity of spore precipitinogens in certain species was demonstrated and inter‐species cross reactions were studied.
A NOTE ON THE PRESENCE OF ANTIBACTERIAL SUBSTANCES IN TOBACCO PLANTS
Authors: DADD A. H.
Published: March 2008

The juice pressed from twelve varieties of tobacco, and materials extracted with ether from these plants, frequently displayed antibacterial activity against several species of bacteria. Some varietal difference in activity towards Ps. tabaci was observed, and there is a suggestion of some correlation between this and resistance to ‘Wildfire’.
BACTERIOLOGICAL CHANGES IN SILAGE AS AFFECTED BY LACERATION OF THE FRESH GRASS
Authors: GIBSON T. , STIRLING ANNA C. , KEDDIE R. M. , ROSENBERGER R. F.
Published: March 2008

Grass, after (a) mincing, (b) chopping (to 1–3 cm), and (c) neither treatment, was ensiled at 30° in the laboratory. The growth of Gram‐negative organisms and of each of the main groups of lactic acid bacteria was fastest in the minced material and slowest in the untreated. Mincing had the special effect of permitting the multiplication of lactic acid bacteria when other silage organisms were losing viability. The pH value decreased much more rapidly and to lower levels in minced silage than it did in silage of untreated grass. Variations in response to the treatments were associated with differences in the bacterial populations on the fresh grass and with properties of the grass. Silage made in larger quantities in concrete silos from untreated or lacerated grass of high sugar content had a bacterial population dominated by lactobacilli and was of low pH irrespective of the treatment applied. Silage made at 30° in the laboratory from the same herbage showed that the effects of laceration were considerable and similar to those of mincing.
THE PRESERVATION OF MARINE BACTERIA
Authors: FLOODGATE G. D. , HAYES P. R.
Published: March 2008

Forty‐five marine bacteria and five nonmarine strains, representing 10 genera, were preserved by freeze drying, by storage in glycerol‐nutrient broth at —29° and under paraffin oil at 1°. Checks on viability and viable counts were made over a two year storage period. At the end of this time 100% of the strains had been preserved by freeze drying, 86% by storage in glycerol‐nutrient broth at low temperature and 72% under paraffin oil. The greatest loss of viability occurred among the vibrios and spirilla whichever of the three methods was used, but coryneforms, achromobacters and micrococci were successfully preserved by all these methods.
A SELECTIVE MEDIUM FOR THE ISOLATION AND ENUMERATION OF COAGULASE POSITIVE STAPHYLOCOCCI FROM FOODS
Authors: HOPTON J.
Published: March 2008

A medium is described for the isolation and enumeration of coagulase positive staphylococci from food products. It was based on the observation that coagulase positive staphylococci produced a zone of clearing in egg yolk emulsion suspended in an agar medium. In conjunction with a modified coagulase test most coagulase positive staphylococci can be confirmed within 24 hr. The majority of coagulase negative staphylococci produced no clearing; when present it was frequently accompanied by a precipitation zone within the clearing area. Sodium azide was used as a selective agent.
A MULTIPLE INOCULATION DEVICE FOR USE WITH FLUIDS
Authors: SMITH D. A.
Published: March 2008

A multiple inoculation device comprising a stainless steel inoculator and Perspex containers for inocula is described. It has been used mainly in the screening of different strains of bacteria for lysogeny, but other applications are listed. Comparison is made with other similar devices.
A STUDY OF THE BACTERIA ON THE ROOT SURFACE AND IN THE RHIZOSPHERE SOIL OF CROP PLANTS
Authors: ROUATT J. W. , KATZNELSON H.
Published: March 2008

The numbers and kinds of bacteria on the root surface (rhizoplane) of the six crop plants, red clover, flax, oats, maize, barley and wheat, and also in the rhizosphere soil (near the roots) have been compared with the numbers and kinds in root free soil. Bacteria isolated from wheat roots have been classified in genera. All the 6 crops, especially red clover, showed a typical rhizosphere effect, and there were also more bacteria in the rhizoplane than in root free soil. Of the 6 crops, red clover had the most methylene blue reducing bacteria, and flax the highest numbers of glucose fermenting bacteria, in both rhizosphere and rhizoplane. Flax also had very many ammonifying bacteria on its roots. The percentage of strains needing amino acids for optimal growth was highest on the root surfaces, and higher in the rhizosphere than in root free soil, in every case. Wheat roots and the wheat rhizosphere yielded a higher proportion of fast growing, acid tolerant and acid producing bacteria than did root free soil. The taxonomic studies showed that Pseudomonas spp. were predominant on and near wheat roots, but Arthrobacter spp. were predominant in root free soil.
CHARACTERISTICS OF ENGLISH ISOLATES OF ERWINIA AMYLOVORA (BURRILL) WINSLOW ET AL.
Authors: BILLING EVE , BAKER LILY A. E. , CROSSE J. E. , GARRETT CONSTANCE M. E.
Published: March 2008

The characteristics of 38 English isolates of Erwinia amylovora were studied independently at East Malling Research Station and at the National Agricultural Advisory Service Laboratories at Wye. The results from both laboratories were similar and indicate considerable physiological homogeneity amongst the isolates. The joint findings are described and compared with those of other authors.
THE EFFECT OF FEEDING COLICINOGENIC ESCHERICHIA COLI ON THE INTESTINAL E. COLI OF EARLY WEANED PIGS
Authors: TADD A. D. , HURST A.
Published: March 2008

The Escherichia coli contents of samples of faeces from 24 early weaned pigs were estimated qualitatively and quantitatively in two experiments. At weaning (10 days of age) the E. coli content was about 108/g of faeces. Haemolytic E. coli, often pathogenic serotypes, emerged at 12–20 days of age and then tended to disappear at 30–40 days of age. Colicinogenic E. coli, isolated from the faeces of pigs from another herd, were grown in a 50 1. batch fermenter and added to the diet of the early weaned pigs, from weaning and until the pigs were 40 days old. Within a few days of feeding the colicinogenic E. coli, colicinogenic types formed 20–50% of the coli‐aerogenes flora of the faeces. The feeding and establishment of colicinogenic E. coli did not suppress the haemolytic E. coli and did not affect the incidence of mortality among the pigs.
AN IMPROVED DIAGNOSTIC AND SELECTIVE MEDIUM FOR ISOLATING COAGULASE POSITIVE STAPHYLOCOCCI
Authors: BAIRD‐PARKER A. C.
Published: March 2008

This paper describes the development and use of a selective and diagnostic medium (ETGPA) for isolating coagulase positive staphylococci from food. It combines an improved form of the selective medium of Zebovitz, Evans & Niven (1955) with the ability to clear egg yolk as a diagnostic character. The new medium is noninhibitory but selective to coagulase positive staphylococci from a variety of sources, and its performance is better than that of four recently published media.
AN AUTOCLAVABLE PLASTIC UNIT FOR REARING ANIMALS UNDER GERM FREE CONDITIONS
Authors: LEV M.
Published: March 2008

A plastic unit for rearing germ free animals is described. This is sterilized by steam under pressure and has been successfully used to rear germ free chicks.
THE ESTIMATION OF NUMBERS OF BACTERIA BY TENFOLD DILUTION SERIES
Authors: TAYLOR J.
Published: March 2008

Results obtained by dilution series are sometimes so unlikely that doubt is cast on the validity of the method. Criteria for the rejection of results are discussed and a Table is given of acceptable results for tests with five tubes for each of three tenfold dilutions. Methods of estimating the concentration of bacteria for other numbers of tubes or of dilutions are suggested. The inherent lack of precision of the dilution series method is stressed.
SOME ASPECTS OF THE MICROBIOLOGY OF FROZEN PEAS
Authors: WHITE ANNE , WHITE HELEN R.
Published: March 2008

The number of bacteria present in commercially frozen peas was found to be usually between 104 and 106/g. Most of the organisms were of two species, Leuconostoc mesenteroides and Streptococcus lactis. After thawing the leuconostocs multiplied more rapidly than the streptococci and in 48 hr the former constituted almost the entire population.

Growth studies of four isolates of each of the above species, both in laboratory media and on blanched peas, showed no difference in growth rates before and after freezing. When some organisms, including potential pathogens, were inoculated on to peas rapid multiplication took place even in the presence of leuconostocs or streptococci.
A QUANTITATIVE AND QUALITATIVE STUDY OF THE LIPOLYTIC ACTIVITY OF SINGLE STRAINS OF SEVEN BACTERIAL SPECIES
Authors: HUGO W. B. , BEVERIDGE E. G.
Published: March 2008

Single strains of Serratia marcescens, Staphylococcus aureus, Micrococcus freudenreichii, Pseudomonas hydrophila, Achromobacter fischeri, Bacillus subtilis and Bacillus cereus were examined for their lipolytic activity, qualitatively using different lipolysis detecting media and quantitatively by means of acid production. The substrates investigated were olive oil, tributyrin, ethyl laurate and ethyl butyrate. The effect of temperature and pH on lipolytic activity, as measured by acid production, has also been investigated.
THE FAECAL COLI‐AEROGENES FLORA OF SOILS FROM VARIOUS GEOGRAPHICAL AREAS
Authors: GELDREICH E. E. , HUFF C. B. , BORDNER R. H. , KABLER P. W. , CLARK H. F.
Published: March 2008

A study has been made of coli‐aerogenes bacteria isolated from 251 soil samples collected from 26 States and 3 foreign countries. Based on land use, the soils were classified in 8 classes of the undisturbed group and one additional group of soils which were known to have been exposed to various kinds of faecal pollution.

Faecal coli‐aerogenes organisms were usually absent, or present in comparatively small numbers only, in undisturbed soils, with most counts being less than 1.8/g. There was a marked increase in the numbers in soils of the polluted group, with a density of between 3,300 and 49,000/g.

Intermediate types represented 76% of the 2,348 strains isolated from the undisturbed soil classes, as contrasted with only 17% of 665 polluted soil strains. The IMViC reactions of the predominant type from the undisturbed group were ‐ + ‐ +, and this type represented 48% of the 2,348 strains isolated. The sanitary significance of the ‐ + ‐ + intermediate type as a soil coli‐aerogenes organism, in relation to data on types from faecal samples and certain remote mountain streams, suggests that the strains giving these IMViC reactions, and which are 45° negative, may possibly be considered as a type characteristic in unpolluted soils but relatively infrequent where faecal pollution has occurred.

Since soil contains high numbers of organisms, other than coli‐aerogenes bacteria, which frequently produce false positive reactions by the ‘confirmed test’ procedure, the ‘completed test’ method is recommended for the examination of soils for coli‐aerogenes organisms.
THE PHYSIOLOGICAL AND SEROLOGICAL PROPERTIES OF STREPTOCOCCUS BOVIS AND RELATED ORGANISMS ISOLATED FROM CATTLE AND SHEEP
Authors: MEDREK T. F. , BARNES ELLA M.
Published: March 2008

The physiological and serological properties of 153 strains of Streptococcus bovis isolated from cattle and sheep have been studied. With 12 specific antisera it was possible to type 75 of the isolates. Neither the fermentation of arabinose nor of raffinose was related to type specificity. The only strain fermenting mannitol was serologically distinct from all the other strains, and the type antigen was probably located on the cell wall whereas with the other 11 types it was capsular.

The distribution of these types in cattle and sheep has been determined together with their changes in individual cows sampled on three occasions over 18 months.
AN APPARATUS FOR THE UNIFORM SPRAYING OF SOLID NUTRIENT SURFACES WITH BACTERIAL SUSPENSIONS
Authors: KAESS G. , WEIDEMANN J. F.
Published: March 2008

Slices of animal tissue or nutrient agar in Petri dishes can be sprayed with the apparatus described to obtain a uniformly distributed bacterial population. The standard error of duplicate counts of individual 1 cm2 samples taken from different portions on sprayed areas was approximately 15%.
THE MINERAL NUTRITION OF HANSENULA SPP. OF YEAST IN RELATION TO FAT PRODUCTION
Authors: FAHMY T. K. , HOPTON J. W. , WOODBINE M.
Published: March 2008

The development of cultures of ‘high fat’ and ‘low fat’ species of Hansenula under different nutritional regimes in shaken culture has been examined. The cultures were sampled at frequent intervals throughout growth, and determinations made of cell number and cell mass, uptake of nitrogen and glucose and synthesis of fat and polysaccharide.

In all media there was an initial phase of rapid multiplication associated with nitrogen uptake, but appreciable increase in yeast mass occurred after the glucose had been exhausted and most of the accretion of fat and polysaccharide occurred during this phase of growth. In a nitrogen deficient medium the production of fat and polysaccharide was accentuated and, whereas the cell count of ‘low fat’ species increased during the second assimilatory phase, that of ‘high fat’ species did not. The behaviour of yeasts in a phosphorus deficient medium simulated that in a nitrogen deficient medium, but behaviour in a medium containing a low concentration of sulphur differed little from that in a complete medium.
Clostridium botulinum in Sweden and the Adjacent Waters
Authors: Johannsen A.
Published: March 2008

Cl. botulinum type E is ubiquitous in Sweden and the adjacent seas. It is of terrestrial origin and is the dominant type in the Baltic's catchment area. The Baltic is thus a reservoir for type E organisms, which spread to neighbouring waters. The high frequency of type E organisms in the peel of stored potatoes may be regarded as one of the most definite indications of the terrestrial origin of this clostridium.