bluuebunny/crossref_metadata_2025 huggingface dataset:
The ethical nature of critical research in information systems
Authors: Stahl Bernd Carsten
Published: March 2008

Abstract. Critical research in information systems is based on and inspired by ethics and morality. In order to support this proposition, this paper will suggest a way of classifying critical research that differs from definitions common IS research. According to the current definition, research is critical when it is motivated by the intention to change social realities and promote emancipation. Based on this critical intention, critical research is furthermore characterized by critical topics, critical theories, and critical methodologies. Using these criteria of critical research, the paper argues that critical research is ethical in nature. To support this view, the paper introduces the concepts of ethics and morality by analysing two traditions of moral philosophy, here called the ‘German tradition’ and the ‘French tradition’. Using three examples of current critical research in information systems, the paper will show that ethics and morality strongly influence critical intention, topics and theories. Having thus established the ethical nature of critical research, the paper concludes by discussing the weaknesses of critical research from the point of view of ethics and morality.
Testicular dysgenesis syndrome and the origin of carcinoma in situ testis
Authors: Sonne Si Brask , Kristensen David Møbjerg , Novotny Guy W. , Olesen Inge Ahlmann , Nielsen John E. , Skakkebæk Niels E. , Rajpert‐De Meyts Ewa , Leffers Henrik
Published: March 2008

Recent increases in male reproductive disorders have been linked to exposure to environmental factors leading to the testicular dysgenesis syndrome (TDS). Testicular cancer is the most severe condition in TDS and studies have shown a clear correlation between risk of testicular cancer and other components of TDS and that the geographical location of the mother during pregnancy can be a risk factor. This suggests that the dysgenesis has its origin in utero and that TDS is initiated by environmental factors, including possibly hormone‐disrupting compounds that act on the mother and the developing foetus, but the genetic background may also play a role. The morphological similarity of carcinoma in situ (CIS) cells (the precursor of the majority of invasive testicular cancers) with primordial germ cells and gonocytes, and overlap in expression of protein markers suggests an origin of CIS from primordial germ cells or gonocytes. CIS cells and germ cell‐derived cancers of the human type have so far not been described in any animal model of TDS, which could be caused by species differences in the development of the male gonad. Regardless of this, it is plausible that the dysgenesis, and hence the development of CIS cells, is a result of disturbed signalling between nurse cells and germ cells that allow embryonic germ cells to survive in the pre‐pubertal and adult testis. The post‐pubertal proliferation of CIS cells combined with aberrant signalling then leads to an accumulation of genetic changes in the CIS cells, which eventually results in the development of invasive testicular cancer in the adult.
Brominated flame retardants as possible endocrine disrupters
Authors: Darnerud P. O.
Published: March 2008

Brominated flame retardants (BFR) are endocrine disrupters in experimental systems, both in vitro and in vivo. Although BFR effects on thyroid hormones are well confirmed, studies of effects on oestrogen/androgen systems are fewer but today growing in numbers. The effects of BFR on other hormone systems are still unknown. Hormonal effect levels in animals start from ca 1 mg/kg b.w., but there are exceptions: effects on spermatogenesis, suggesting hormonal causes, have been observed at a low dose (60 μg/kg b.w.) of a polybrominated diphenyl ether (PBDE) congener, BDE‐99. It could be concluded that hormonal effects are of importance in risk assessment, and in some cases where effects are seen at low levels safety margins may be insufficient. One additional uncertainty is the lack of reliable human data that could be used to support animal BFR observations. In spite of the recent regulation of PBDE production, levels of both PBDE and of other BFR groups are still present in environmental samples. Thus, we have to deal with the possible effects of human BFR exposure for times to come. In order to reduce BFR exposure, the routes of exposure should be carefully examined and ways to reduce levels in major exposure routes considered.
THE INFLUENCE OF MASTITIS MILK AND LATE LACTATION MILK ON THE RESULTS OF THE PRESCRIBED RESAZURIN AND METHYLENE BLUE TESTS
Authors: Thomas S. B. , Bowie D. A.
Published: March 2008

THE INFLUENCE OF MASTITIS MILK AND LATE LACTATION MILK ON THE RESULTS OF THE PRESCRIBED RESAZURIN AND METHYLENE BLUE TESTS
THERMODURIC ORGANISMS IN MILK. PART III. PROVISIONAL STANDARD TECHNIQUE FOR THE LABORATORY PASTEURIZATION TEST FOR MILK, AND RINSES AND SWABS OF DAIRY EQUIPMENT, WITH SUGGESTIONS FOR INTERPRETATION OF RESULTS
Authors: EGDELL J. W. , THOMAS S. B. , CLEGG L. F. L. , CUTHBERT W. A.
Published: March 2008

A standard method for the application of the laboratory pasteurization test for milk, and rinses and swabs of dairy equipment, is described. The interpretation of the thermoduric colony counts so obtained is discussed, and tentative advisory standards are suggested.
THE EFFECT OF PENICILLIN ON THE METHYLENE BLUE REDUCTION TIME AND KEEPING QUALITY OF MILK
Authors: ROWLANDS A.
Published: March 2008

The addition to 32 samples of freshly produced milk from 16 farms of 0.25, 0.5 and 1.0 unit/ml. of penicillin tended to increase the methylene blue reduction time at 37—38°, and to improve the keeping quality at 22°, irrespective of season. In no case was the reduction time decreased or the keeping quality made worse. In general, the effects were almost as marked with 0.25 unit as with the higher concentrations. The increases in the reduction time ranged from 0 to over 3 hr. in winter and from 0 to 2.5 hr. in summer. The delay in reaching the end‐point of the keeping quality test ranged from 0 to 15 hr. in winter and from 0 to over 18 hr. in summer. The response to penicillin differed with the two tests in individual samples. In some cases the methylene blue reduction time was markedly increased but keeping quality was little affected: in others, the reverse was observed.

In both winter and summer streptococci predominated in the control samples at the keeping quality end‐point, but with penicillin added Gram‐negative rods often gained the ascendancy. At the time of reduction of methylene blue the flora of the winter control samples consisted mainly of streptococci and micrococci, but in the presence of penicillin the proportion of Gram‐negative rods generally increased: in summer Gram‐negative rods predominated in the control samples and in the presence of penicillin.

Practically all the Gram‐negative rods were resistant to penicillin. All the micrococci and most of the streptococci were sensitive to penicillin; the resistant streptococci were strains of Str. faecalis. The variable distribution of resistant and sensitive organisms. coupled with the possible production of penicillinase, probably accounts for the variable effect of penicillin on the methylene blue and keeping quality tests in different samples.
THE GROWTH OF CLOSTRIDIUM BOTULINUM IN ACID BREAD MEDIA
Authors: INGRAM M. , ROBINSON R. H. M.
Published: March 2008

The effect of acidity on the growth of Cl. botulinum was studied by following changes in the viable count of cultures in acid buffered broths containing bread crumbs, after inoculation with about 104 vegetative cells or spores/ml. In 9 out of 10 experiments growth did not occur below pH 5.0; in the tenth it took place at pH 4.8. There was no significant difference between vegetative cells and spores.
THE NUTRITIONAL REQUIREMENTS OF THE PREDOMINANT BACTERIAL FLORA OF THE SOIL
Authors: TAYLOR C. B.
Published: March 2008

Several aspects of techniques for nutritional classification of soil bacteria have been critically investigated. The methods used by recent Canadian workers are found to be unsatisfactory; (a) because their seven standard media fail in several respects to give an unequivocal grouping; (b) because some of the media used contain inadequate concentrations of essential nutrients; (c) because recommended incubation times are in some cases too short.

A simpler method of classification into five nutritional groups, using longer periods of incubation and more satisfactory differential media, has been used to compare soils receiving different manurial treatments. Results indicate that other factors, such as the well‐known rapid fluctuation in bacterial numbers which occurs in all soils, may obscure any effects of soil treatment unless a very elaborate system of controls is adopted. It is suggested that an even simpler method of nutritional grouping into three classes may be of value: (a) organisms capable of using ammonia nitrogen; (b) organisms requiring amino‐acid nitrogen, with or without vitamin supplements; (c) organisms requiring more complex nitrogenous materials.

The possibility of developing a grouping technique by direct plating on differential solid media has been studied. It is considered that this is not possible; association effects on plates with mixed colonies suffice to obscure differences between a series of media of increasing nutritional complexity.

The growth‐promoting properties of soil‐extract are believed to be due in part to complex nitrogenous substances, which can be replaced by certain concentrations of suitable peptones, and in part to such cations as calcium, magnesium and strontium. The concentration of such cations needed to allow growth of exacting strains is related to the concentration of peptone in the medium and it is suggested that they may act by antagonising in some way the inhibitive effects of certain peptone constituents.
THE BACTERIOLOGY OF FARM WATER SUPPLIES: A STUDY OF THE COLONY COUNT IN 48 HOURS AT 37°
Authors: THOMAS S. B. , THOMAS BLODWEN F. , FRANKLIN PATRICIA M.
Published: March 2008

SUMMARY: Colony counts in 48 hr. at 37° were much higher in farm water supplies derived from rivers, streams, canals and unprotected wells than in water from springs, protected wells, upland surface waters and chlorinated supplies. Relatively few of the upland surface waters had counts exceeding 102/ml., but the counts for unprotected shallow wells were as high as those for rivers, streams and canals.

There was a general association between colony counts at 37° and presumptive coli‐aerogenes counts, but high 37° colony counts could not always be accepted as an indication of sewage or faecal pollution and obviously polluted waters sometimes had low colony counts at 37°.

Irrespective of the magnitude of the colony count, the majority (63%) of the colonies were Gram‐negative rods, though they formed a higher proportion of the flora in high than in low count waters. Aerobic spore‐forming rods constituted nearly 20% of the colonies and micrococci 10%, while Gram‐positive rods which did not form spores were present in small numbers at all colony count ranges. Streptococci were relatively rare, forming less than 2% of the colonies.

Approximately 25% of the 1,912 cultures isolated from colonies at 37° produced acid and gas in MacConkey's broth at 37°, but 7% of the 488 presumptive coli‐aerogenes cultures were aerobic spore‐forming rods. Typical coli‐aerogenes bacteria constituted 38% of the Gram‐negative rods and 24% of all the colonies examined. Surprisingly few colonies resembled Bact. coli type I in producing acid and gas in MacConkey's broth at 44°, and 13 (6.8%) of the 192 which did so were aerobic spore‐formers resembling Bacillus macerans.

Slightly over a third of the cultures produced an acid or proteolytic reaction in litmus milk within 2 days at 22°.

The results indicate that the colony count in 48 hr. at 37° does not contribute much useful information additional to that obtained from the presumptive coli‐aerogenes test at 37° and the Bact. coli test at 44°.
THE ENUMERATION OF LACTOBACILLI ON GRASS AND IN SILAGE
Authors: KEDDIE R. M.
Published: March 2008

SUMMARY: For the enumeration of lactobacilli on grass and in silage the following medium has shown promise: peptone, meat extract and glucose, 10 g. each; tomato extract, 200 ml.; yeast autolysate, 50 ml.; Tween 80, 0.5 ml.; agar, 15 g., in a final volume of 1 1. and containing acetic acid/sodium acetate buffer in 0.2M concentration; pH 5–4. The medium was adjusted to pH 5–4 before sterilization and the requisite amount of concentrated pH 5.4 acetate buffer added just before plating. Double laver plates were used.

The only other silage organisms which in this medium formed colonies comparable in size with those of lactobacilli were heterofermentative streptococci and a micrococcus.
SOME ORGANIC SUBSTANCES AND THE NITRIFYING BACTERIA
Authors: MEIKLEJOHN JANE
Published: March 2008

SUMMARY: The rate of nitrification in mixed cultures was not affected by the simultaneous decomposition of cellulose. No stimultion of the rate of nitrification was observed in cultures containing: culture filtrates, soil extract, thiamin, yeast extract, urine, or β‐indolylacetic acid. These substances either had no effect or, in larger doses, delayed or stopped nitrification.

Peptone was toxic to the nitrifying bacteria. Potassium chlorate did not affect the oxidation of ammonia to nitrite, but stopped the oxidation of nitrite to nitrate in cultures, as it does in soil. M/25 sodium fluorides stopped the oxidation of ammonia to nitrite.
OBSERVATIONS ON THE MICROFLORA OF FERMENTING CACAO BEANS IN TRINIDAD
Authors: ROMBOUTS J. E.
Published: March 2008

SUMMARY: A numerical analysis is given of the average microflora of fermenting cocoa beans in Trinidad sweat boxes. Both the viable count of all micro‐organisms and the relative numbers of the main groups involved were estimated.

The influence of the prevailing temperature and pH of the environment on the sequence of microbial development is considered, and the main chemical changes taking place are noted.

The influence of atmospheric conditions is discussed and the desirability of a thorough microbiological analysis of the fermentation process in relation to cocoa quality is stressed.
THE ASSESSMENT OF THE BACTERIOLOGICAL CONDITION OF MILK BOTTLES
Authors: GRIFFITHS D. G. , MORGAN K. J. , PRITCHARD BARBARA , THOMAS S. B.
Published: March 2008

SUMMARY: A study of the relative values of a number of bacteriological tests for assessing the condition of milk bottles indicated that the colony count of the bottle rinse solution on yeastrel milk agar incubated for 4 days at 30°, combined with a clot‐on‐boiling test applied to 1 ml. of rinse in 9 ml. of sterile milk after incubation for 72 hr. at 19–20°, gave the most useful results.

The mean of the ratios of colony counts at 30° to those at 37° was 15·1, while it was as high as 22·9 for rinses with 37° of over 600 for an unsatisfactory bottle should be retained when the test is done at 30°. The thermoduric colony count of rinses of milk bottles, even when laboratory pasteurized in milk, did not provide any additional information to that given by the colony count at 30° made without pasteurization. A high proportion of the organisms in bottle rinses survived laboratory pasteurization in milk, the survival rate being highest in efficiently treated bottles.

The clot‐on‐boiling test gave results in general agreement with colony counts and served to indicate the potential influence of badly contaminated bottles on the keeping quality of milk placed in them. A substantial proportion of rinses with satisfactory colony counts reduced methylene blue within 48 hr. at 19–20°.

Colony counts at 37° were on the average much lower for bottles treated with steam than for bottles submitted to detergent treatment in various types of bottle washing machines. Treatment of bottles by steam or hypochlorite was more efficiently done on the farms than at the dairies.
THE ESTIMATION OF SULPHATE‐REDUCING BACTERIA (D. DESULPHURICANS)
Authors: GROSSMAN JOY P. , POSTGATE J. R.
Published: March 2008

SUMMARY: Sodium sulphide or cysteine stimulated the growth of sulphate‐reducing bacteria; small populations often did not grow without such supplements. Ascorbic acid, glutathione or thiolacetic acid had similar properties but thiolacetic acid was sometimes inhibitory, Dilution counts in liquid media or colony counts in agar media did not bear any regular relation to the total count unless one of these supplements was present. With suitable precautions colony counts reaching 50 to 60% of the total count were obtained in media incorporating cysteine and a ferrous salt (as an indicator of sulphide formation).

Samples of natural origin containing sulphate‐reducing bacteria gave greater viable counts in cysteine‐iron media than in unsupplemented media. Blackend culture tubes with natural populations were sometimes due to cysteine‐decomposing organisms; further examination of positive tubes was therefore necessary.
ROLL TUBES AND AGAR STRIP TUBES FOR THE BACTERIAL COLONY COUNT OF MILK
Authors: HIGGINBOTTOM CONSTANCE
Published: March 2008

SUMMARY: Roll‐tube colony counts, using the Astell equipment, were lower than the corresponding Petri dish counts with 27 out of 31 raw milks (87%). The difference between the counts by the two methods was greater than 25% of the plate count for 12 (39%) of the samples.

When the same dilution of milk was used for both strip‐tube and plate colony counts, about equal numbers of samples gave counts from the strip tubes above and below about the colony count from plates. When, in order to obtain a more reasonable strip‐tube count, the plates and strip tubes were prepared from different dilutions of the milk, the counts from the latter were, with only 3 exceptions out of 35 milks, below those from the former. The difference between the counts was greater than 25% of the plate count for 15 (43%) of the milks, a figure similar to that obtained in comparing roll‐tube and plate colony counts.
EXPERIMENTS ON GROWTH MEDIA FOR LACTOBACILLI
Authors: COX C. P. , BRIGGS MARY
Published: March 2008

A medium permitting consistently good growth of known strains of lactobacilli was determined using nineteen strains considered difficult to grow. For the culture media tested various concentrations of albumin, starch, Tween 80, sodium oleate and Yeastrel were added to tomato dextrose broth and strain growth was measured by a photo‐electric absorptiometer. Statistical analysis showed that, of the combinations tested, the best response was achieved by the addition to tomato dextrose broth of Tween 80 (0.1% v/v) and Yeastrel (0–6% w/v) with or without 0.5% of starch.
THE EFFECT OF SATURATED FATTY ACIDS ON OXYGEN UPTAKE BY PENICILLIUM CHRYSOGENUM
Authors: ROLINSON G. N.
Published: March 2008

The respiration of washed mycelium of Penicillium chrysogenum suspended in phosphate buffer solutions in the presence of the sodium salts of n‐fatty acids containing even numbers of carbon atoms was examined, using mycelium which had been grown in a lactose‐corn steep liquor‐salts medium in submerged culture. At pH 6.4 and at a concentration of 1.0% (w/v), acids of short (C2–C4) and long (C16–C18) chain length were readily oxidized, but acids of intermediate chain length (C8–C10) were toxic and completely inhibited even the endogenous respiration. The two latter acids were however oxidized at lower concentrations at pH 6.4. The toxicity of sodium caprate (C10) also depended on the pH of the system. At pH 7.0 and above, 0.02% caprate was readily oxidized; but below pH 6.0 that concentration became increasingly toxic and at pH 4.5 all respiration was inhibited. However, even at pH 4.5 very low concentrations of sodium caprate were oxidized. At pH 6.3, 0.025% sodium caprate completely inhibited the oxidation of glucose, peptone and sodium acetate but the oxidation of oleic acid was only partially suppressed. A concentration of 0.05% was required to inhibit completely the oxidation of oleic acid.
THE DISINFECTION OF MILK CANS WITH SODIUM HYPOCHLORITE
Authors: HOY W. A. , NEAVE F. K.
Published: March 2008

SUMMARY: The cleansing of milk cans by sodium hypochlorite has shown that the physical conditions of the cans exerts a greater influence on the efficiency of disinfection than the pH, concentration, or time of contact of the hypochlorite solutions used.
A FACTORIAL INVESTIGATION OF SOME TEST CONDITIONS IN THE EVALUATION OF THE DISINFECTANT PROPERTIES OF QUATERNARY AMMONIUM COMPOUNDS USING A DRIED FILM OF BACTERIUM COLI TYPE I
Authors: CLARKE PAMELA M. , GARVIE ELLEN I.
Published: March 2008

SUMMARY: In a series of experiments in which a suspension of Bacterium coli strain 28.D.10, dried on a metal surface, was treated with alkyldimethylbenzylammonium chloride (BC) and cetyltrimethylammonium bromide (CTAB), the variability of the results compared favourably with that observed by other workers in the same field of disinfection, but using different methods.

Quantitative estimates were obtained for the effects and interactions, on the bactericidal activity of the quaternary ammonium compound, of time and temperature of exposure, and of concentration of the compound. Increases in each of these factors reduced the percentage of surviving organisms. CTAB was less active than BC. Changes in pH between 5 and 9 did not affect the estimated activity of BC or CTAB, but in the presence either of phosphate or of borate buffers the bactericidal activity of both compounds was decreased.
SOME OBSERVATIONS ON THE BACTERIAL CONTENT OF WATER IN WATERCRESS BEDS
Authors: JONES G. ELIS , BAKER LILY A. E.
Published: March 2008

SUMMARY: Samples of water flowing into watercress beds had higher bacterial contents during the summer months although this was less marked among samples from deep underground sources. Outlet samples showed higher contents than inlet samples and the bacterial content varied markedly with season, being highest in summer.

The presumptive coli‐aerogenes contents at 30°, 37° and 44° also showed a similar seasonal variation among samples from the outlets but the marked inferiority of samples other than from bores was no longer apparent after the water had flowed through the beds. The dominant types were Bact. aerogenes type I, pectate liquefiers, Bact. coli type I, and Intermediate type I.

The importance of the pectate liquefiers was confirmed by plating on pectate gel and by their isolation from these plates and from MacConkey's broth.
BACTERIAL CULTURE MEDIA FROM WASTE HEVEA LATEX SERA
Authors: TAYSUM D. H.
Published: March 2008

SUMMARY: Two waste products of the natural latex industry in Malaya, at present rejected in large quantities, have been found suitable for conversion into bacterial culture media for routine use. Details of their preparation and performance are given.
THE ASSOCIATIVE GROWTH OF SOME THERMODURIC BACTERIA IN PASTEURIZED MILK
Authors: WILLIAMS D. J.
Published: March 2008

SUMMARY: Three strains of aerobic spore forming bacteria have been studied in association with thermoduric streptococci in pasteurized milk at different temperatures. Generally the development of each component organism of the mixtures was unaffected in the initial stages by the presence of the other, though later the spore formers were frequently adversely affected. Acid production by the mixed cultures was compared with that of the pure cultures under the same conditions of incubation. Generally more acid was formed by the mixtures, particularly at the higher temperatures of incubation. Gas formation was noted by a culture of Streptococcus faecalis in association with the spore formers.
THE DIFFERENTIATION OF SPECIES OF LACTOBACILLI AND STREPTOCOCCI BY MEANS OF PAPER PARTITION CHROMATOGRAPHY
Authors: MATTICK A. T. R. , CHEESEMAN G. C. , BERRIDGE N. J. , BOTTAZZI V.
Published: March 2008

SUMMARY: Washed cells of micro‐organisms were extracted with 10% acetic acid and the extracts subjected to two‐dimensional paper partition chromatography. With closely related strains within species already defined serologically and physiologically, the patterns of amino acids and peptides revealed by ninhydrin were relatively constant; but with different species variations were noted, even between species hitherto not easy to differentiate.
A SIMPLE PROCEDURE TO DETECT NISIN IN CHEESE
Authors: MOCQUOT G. , LEFEBVRE ELISABETH
Published: March 2008

SUMMARY: A suitable amount of agar medium inoculated with a test organism sensitive to nisin (Lactobacillus lactis or Streptococcus cremoris) is poured on a cheese cylinder placed in a Petri dish. After a convenient incubation time the presence of a clear zone around the cheese cylinder will indicate the presence of nisin.

The method is applicable both to natural and processed cheese and can also be used for other antibiotics that may be present in cheese.
A NOTE ON THE SOURCE AND IDENTIFICATION OF THE STRAINS OF LACTOBACILLI
Authors: Sharpe M. Elisabeth
Published: March 2008

SUMMARY: The examination of 73 strains of the Lactobacillus casei‐plantarum group has shown that chromatograms can be used to decide the species in this group. Further subdivision into types may also be made.
ADVISORY MICROBIOLOGICAL STANDARDS AND TOLERANCES FOR RAW MILK
Authors: GRIFFITHS D. G. , DRUCE R. G. , THOMAS S. B.
Published: March 2008

SUMMARY: To study the value of recent modifications of microbiological tests used for advisory purposes, samples of tuberculin tested milk, taken at weekly intervals over a 5 year period from the Trawscoed Experimental Husbandry Farm and selected at random during a 12 months period from farms in Wales, were examined by a temperature compensated keeping quality test at 22°, colony count on Yeastrel milk agar in 3 days at 30° and coli‐aerogenes colony count on violet red bile agar in 20–24 hr at 30°.

The results show that milk produced and handled under hygienic conditions can be expected to have colony counts of less than 2 × 104/ml and coli‐aerogenes colony counts less than 10/ml when examined within 18 hr of milking.
VARIATIONS IN THE INTESTINAL FLORA OF RATS ON PURIFIED DIETS. I. THE EFFECT OF PYRIDOXINE DEFICIENCY ON THE LEVEL OF COLI‐AEROGENES ORGANISMS
Authors: COPPING ALICE M. , WHITE HELEN R.
Published: March 2008

SUMMARY: Presumptive counts were made of several groups of intestinal organisms in caecal and rectal contents of rats fed on purified diets with and without adequate levels of pyridoxine. In the absence of pyridoxine the numbers of coli‐aerogenes bacteria were higher in the caecal contents of rats fed on a purified diet containing glucose. This might not have been so if the diet had contained starch instead of sugar.
THE ENUMERATION OF FAECAL STREPTOCOCCI IN FOODS, USING PACKER'S CRYSTAL VIOLET SODIUM AZIDE BLOOD AGAR
Authors: MOSSEL D. A. A. , VAN DIEPEN H. M. J. , DE BRUIN A. S.
Published: March 2008

SUMMARY: Packer's crystal violet sodium azide blood agar (Packer, 1943) used in poured plates at 36·1°, gave satisfactory recovery of pure cultures of Lancefield group D streptococci and completely inhibited the growth of 11 other species of aerobic and anaerobic food bacteria, including Strep. lactis (5 strains). Later, however, one group N streptococcus was obtained which did grow in Packer's agar at 36·1°. To eliminate this organism the incubation temperature had to be increased to 39·5°, using agar strips (Stirling et al. 1950) incubated in a water bath to secure strict temperature control. Under these conditions the recovery of typical group D streptococci was never consistently below 50% of the count in tryptone dextrose yeast extract agar at 31·1°.
The Preservation of Bacteriophage by Drying
Authors: Annear D. I.
Published: March 2008

SUMMARY: Two bacteriophages were stored a t room temperature after being dried and recoveries of them were compared with those from broth suspensions which were stored at 4°. The T, phage of Escherichia coli was recovered without loss from both broth and dried material after 30 months. Some loss of C phage of Bacillus meguteriurn occurred on drying but recoveries from the desiccates were much higher than from the broth suspensions after prolonged storage.
A SHAKING DEVICE FOR LIQUID CULTURES
Authors: MULCOCK A. P. , ABLEY B. J.
Published: March 2008

SUMMARY: Details are given for the construction of a reciprocating shaking device for liquid cultures. Up to 36 litres can be shaken at one time. The machine is compact, the base being only 28 in. square.
THE NORMAL FLORA OF THE BOVINE RUMEN. IV. QUALITATIVE STUDIES OF LACTOBACILLI FROM COWS AND CALVES
Authors: PERRY K. D. , BRIGGS C. A. E.
Published: March 2008

SUMMARY: Two hundred and four samples of rumen contents were taken from eight fistulated cows receiving various diets, and seventy‐one samples from twelve calves. From dilution counts of these samples, 91 isolates of Gram‐positive catalase‐negative rods were obtained, and by means of physiological and serological tests, 78 (95%) out of 82 lactobacilli were characterized as follows: Lactobacillus fermenti (33 strains), L. acidophilus (21), L. casei (17) and L. plantarum (7). Indications were obtained of progressive establishment of lactobacilli in the rumen of the growing calf, L. fermenti predominating. In the cow, L. acidophilus was generally associated with hay plus concentrates diets and L. casei with silage, whereas with grass small numbers of several species of lactobacilli were found.
METHODS OF ASSESSING THE SPORICIDAL EFFICIENCY OF AN ULTRA‐HIGH‐TEMPERATURE MILK STERILIZING PLANT. II. EXPERIMENTS WITH SUSPENSIONS OF SPORES IN MILK
Authors: FRANKLIN J. G. , WILLIAMS D. J. , CHAPMAN HELEN R. , CLEGG L. F. L.
Published: March 2008

SUMMARY: The sporicidal efficiency of an ultra‐high‐temperature (UHT) milk processing plant has been tested using spores of a strain of Bacillus subtilis in milk. With the inoculum and volume of milk adjusted to obtain a countable number of survivors by a conventional dilution counting method, a temperature of 130·5° with the minimum time setting of the plant was found necessary to give a destruction of 99·99999%. This temperature was lower than that found previously (135°) for spores suspended in water and evidence is produced to support the suggestion that UHT milk may be inhibitory to the germination and/or subsequent growth of heated spores.
‘BITTY’ CREAM: THE OCCURRENCE AND SIGNIFICANCE OF BACILLUS CEREUS SPORES IN RAW MILK SUPPLIES
Authors: BILLING EVE , CUTHBERT W. A.
Published: March 2008

SUMMARY: Methods for determining the Bacillus cereus content of milks and of rinses of dairy equipment are described and their limitations discussed. Milk samples from various sources were examined throughout the year for ‘bittiness’ as well as for B. cereus. The organism was not detected in all samples showing bittiness. There was a marked seasonal variation in the B. cereus index of raw milk supplies; maximum numbers were obtained from July to September and minimum numbers in April and May. Rinses of farm dairy equipment yielded few B. cereus spores but milk cans not uncommonly contained large numbers, especially in the summer months, when 10·5% of cans showed more than 5 × 103/can. Preliminary observations on other sources of B. cereus are described and some of the problems of the control of this organism in raw milk supplies are discussed.
THE UPTAKE OF MERCURY BY SEEDS TREATED WITH MERCURIC CHLORIDE SOLUTION, AND ITS SUBSEQUENT RELEASE
Authors: DADD A. H. , JACOBS S. E.
Published: March 2008

SUMMARY: When sweet pea seeds were soaked in mercuric chloride solution a considerable quantity of mercury was taken up and was not removable by a washing procedure even more thorough than that usually employed in the technique for the surface sterilization of plant tissues. To remove the bulk of it, soaking the seed for 48 hr was needed.
OBSERVATIONS ON FOAMING AND ITS INHIBITION IN A BACTERIAL CULTURE
Authors: PIRT S. J. , CALLOW D. S.
Published: March 2008

SUMMARY: Inhibition of foaming in a continuous culture of bacteria has been studied. At first, foaming was inhibited by the addition of antifoam to the culture only when a foam layer was present. When the antifoam was added in this way foaming often became intense and antifoam additions had to be more and more frequent. In a preferred method the antifoam was added at regular intervals which were sufficiently short to inhibit foaming completely throughout the intervening periods. This method required less antifoam than the other. The effects of foaming in cultures, its causes, and allied problems are discussed.
THE ADVANTAGES OF A PLATINUM TUBE DROPPING PIPETTE FOR MAKING COLONY COUNTS
Authors: DAVIS J. G. , BELL JEAN S.
Published: March 2008

SUMMARY: For routine purposes where a large number of tests is involved the dropping pipette technique has many advantages over other methods of determining the colony count. However, glass pipettes are fragile and much time and labour have to be used in making and calibrating replacements. A robust platinum tube dropping pipette has been found very satisfactory. No difficulty was experienced in obtaining complete sterility of the pipettes in the technique described, and reproducibility of drop size was good.
LACTIC ACID BACTERIA AS SPOILAGE ORGANISMS OF FRUIT JUICE PRODUCTS
Authors: CARR J. G.
Published: March 2008

SUMMARY: The spoilage of wines and ciders by lactic acid bacteria is described. The pioneering work on wine bacteriology at the turn of the century is discussed in addition to modern work carried out in Australia and the U.S.A. Similarly, past and present work on the spoilage of ciders by lactic acid bacteria is discussed, special reference being made to their activity against malic acid as well as chlorogenic acid and its derivatives.
THE CHANGES WITH AGE IN THE RESISTANCE OF ESCHERICHIA COLI TO DRYING UNDER ATMOSPHERIC CONDITIONS
Authors: LEMCKE RUTH M.
Published: March 2008

SUMMARY: The resistance to drying under atmospheric conditions of Escherichia coli cells suspended in water, broth and horse serum was investigated. Cells from cultures in the early (logarithmic) growth phase were more susceptible than older cells, and this, together with the fact that the strain of E. coli used was very sensitive to drying, even in a protective menstruum such as horse serum, made it unlikely that the clearer chromatin staining obtained with cells from young than from old cultures could be attributed to the occurrence of less disruption of the former during drying of the films.
STUDIES ON AEROSOL DISINFECTION OF POULTRY PREMISES
Authors: McKENZIE D. A. , LAMBERT JEAN , GETTY J.
Published: March 2008

SUMMARY: A study has been made of the effectiveness of an Ibcol‐triethylene glycol mixture for either atmospheric or surface disinfection in various types of poultry premises. Only a moderate bactericidal action was obtained with atmospheric disinfection using E. coli as the test organism. With a stronger mixture, a complete kill was obtained for surface disinfection with overnight exposure but the reduction in numbers of the test organisms with 30 min exposure did not exceed 75% in any experiment. Very satisfactory results were obtained with a formalin‐water aerosol.
THE EFFECT OF NISIN ON THE GROWTH OF CELLS AND SPORES OF CLOSTRIDIUM WELCHII IN GELATINE
Authors: EASTOE J. E. , LONG JOAN E.
Published: March 2008

SUMMARY: The action of various concentrations of nisin on the development of cells and spores from untreated and heated suspensions of Clostridium welchii added to gelatine has been investigated, using a tube colony count technique. The development of vegetative cells was prevented by the presence of 2 Reading Units (R.U.) of nisin/ml of the final culture medium, although the effective concentration may have been 6 R.U./ml. Approximately 40 R.U./ml prevented colony formation from spores. Gelatine containing nisin was dried. A considerable proportion of the activity of the antibiotic was still present after storage for 5 weeks.
PHYSICAL ASPECTS OF STERILIZING COTTON ARTICLES BY STEAM
Authors: HENRY P. S. H.
Published: March 2008

SUMMARY: In this paper some of the physical processes occurring when cotton articles are sterilized in metal drums or bare packages in an autoclave are discussed, with special reference to the case where a good vacuum is drawn before the admission of steam. It is shown that under these conditions the heating will be quick, uniform, regular and reversible, and that no separate drying‐off period should be needed. Calculation of the temperatures and moisture contents reached during the ‘quasiequilibrium’period shows that the ‘superheating’of the cotton is self‐limiting, can never exceed a few degrees Centigrade, and will not give rise to serious weakening of the cotton. Calculation of the rate of irreversible penetration of moisture into the contents of the drum shows that this can easily be limited to the wrapping layer. Information is given on the ‘heat‐tendering’of cotton, and the advantages of using a good vacuum are summarized.
STUDIES OF THE GROWTH OF PENICILLIUM CHRYSOGENUM IN CONTINUOUS FLOW CULTURE WITH REFERENCE TO PENICILLIN PRODUCTION
Authors: PIRT S. J. , CALLOW D. S.
Published: March 2008

SUMMARY: A filamentous mould was cultured by the continuous flow method in which medium is supplied at a constant rate and the culture volume is kept constant. Flow rates up to 0·1 culture volumes/hr were used. The mycelial dry weight concentration and the yield of mycelium/g of carbon source used were equal to or slightly greater than the maximum obtained in batch culture. With glucose concentrations up to 80 g/1. at a flow rate of 0·05 culture volumes/hr, about 45% of the substrate carbon was converted into mycelial carbon and the remainder oxidized to CO2.

With unlimited amounts of all nutrients available growth of the mould followed the exponential law, as does bacterial growth, and therefore the mould had a constant doubling time.

The oxygen demand of the mould as function of growth rate was determined.

Conditions were found under which the rate of penicillin production/g of mycelium remained at its maximum value for 1000 hr.
A MEDIUM FOR THE CULTIVATION OF LACTOBACILLI
Authors: De MAN J. C. , ROGOSA M. , SHARPE M. ELISABETH
Published: March 2008

SUMMARY: An improved growth medium for lactobacilli is described. It supports good growth of lactobacilli generally and also is particularly useful for a number of fastidious strains which grow only poorly in other general media. In addition, tomato juice, a highly variable material, is not required. In a slightly modified form, it can also be used as a basal medium for fermentation tests.
A METHOD FOR ESTIMATING LOW CONCENTRATIONS OF DIFFUSIBLE PENICILLINASE
Authors: HEDGES A. J.
Published: March 2008

A method suitable for the assay of low concentrations of diffusible penicillinase has been developed and its technique is described. The concentration of soluble penicillinase in a sample is estimated by comparing its rate of diffusion in an agar gel with that of a standard preparation, the extent of diffusion being detected, after a fixed period, by a microbiological method employing ‘zones of exhibition’. The method enables four similar samples to be compared on a single large plate in the form of a randomized Latin Square. Under these conditions a concentration of penicillinase able to inactivate only 2 units of penicillin/ml/hr was measurable with an experimental error (95% confidence interval) of c.±10%.
THE EVALUATION OF SURFACE ACTIVE DISINFECTANTS FOR USE IN MILK PRODUCTION
Authors: COUSINS CHRISTINA M. , HOY W. A. , CLEGG L. F. L.
Published: March 2008

Details are given of a can test for evaluating detergent‐sterilizers intended for farm dairy use. The materials are compared with a standard hypochlorite‐detergent solution for their ability to cleanse milk‐soiled metal surfaces resembling those encountered in practice.

Results from the can test have been compared with those from a suspension test. This comparison suggests that the suspension test is of value for the initial screening of QAC‐detergent mixtures, since those with poor disinfectant properties in suspension acted poorly on surfaces. However, products giving good disinfection in suspension may fail to cleanse a soiled surface if they are poor detergents.
THE PSEUDOMONAS AND ACHROMOBACTER GROUPS OF BACTERIA IN THE SPOILAGE OF MARINE WHITE FISH
Authors: SHEWAN J. M. , HOBBS G. , HODGKISS W.
Published: March 2008

Total colony counts and analyses of the bacterial flora of the skin slime of cod, carried out at 5‐day intervals during the stowage of the fish in ice, showed that organisms of the genera Pseudomonas and Achromobacter became predominant in the later stages of spoilage.
A NOMOGRAPH FOR DETERMINING FIFTY PER CENT ENDPOINTS
Authors: TINT H. , GILLEN ANNE
Published: March 2008

A universal nomograph is presented for determining the 50% response dose (RD50) from the cumulative percentage response. Instructions are given for the preparation of simpler nomographs for particular test conditions.
TWO TYPES OF XYLAN FERMENTING BACTERIA FROM THE SHEEP RUMEN
Authors: HOBSON P. N. , PURDOM MARY R.
Published: March 2008

Different types of media containing xylan were used to culture bacteria from the sheep rumen. The results suggest that facultatively anaerobic bacteria are not active in the ruminal fermentation of xylans. Gram‐negative curved rods were the predominant bacteria growing in all anaerobic cultures under CO2 and those isolated were similar to Butyrivibrio fibrisolvens. The properties of two types of xylan fermenting bacteria are given.
THE SAFETY AND CLEANLINESS OF WATERS AND FOODS
Authors: McCOY J. H.
Published: March 2008

There are two reasons for the bacteriological examination of water supplies and foods; first to determine whether the commodity is safe to consume, i.e. that pathogenic organisms are absent; second, to determine whether the commodity is clean, i.e. that the level of nonpathogenic organisms is such that the commodity will suffer no significant deterioration in quality during normal conditions of storage and transport between preparation and delivery to the consumer. In the examination of water supplies and of shellfish growing in polluted waters, both the safety and the cleanliness of the product are assessed by a single examination for the presence of the normal inhabitants of the intestinal tract of man and animals. In the examination of foods only the cleanliness of the product is assessed by an examination for the presence of normal intestinal inhabitants. The safety of foods can be assessed only by examination for the presence of pathogenic organisms.
AN ECOLOGICAL INVESTIGATION ON THE USEFULNESS OF TWO SPECIFIC MODIFICATIONS OF EIJKMAN'S TEST AS ONE OF THE METHODS USED FOR THE DETECTION OF FAECAL CONTAMINATION OF FOODS
Authors: MOSSEL D. A. A.
Published: March 2008

An investigation has been carried out on the suitability of two modifications of Eijkman's heat tolerance test which had previously been found useful for the detection of Escherichia coli strains of faecal origin in foods. These were: plating on Chapman's lactose tergitol‐triphenyltetrazolium agar incubated at 44°, and enrichment in brilliant green‐bile fluid incubated at 44°, followed by subculture in the same medium and in tryptone water to test indole formation. Two materials having quite different histories of faecal contamination were examined. These were ‘coliform positive’ ice cream samples and bulk raw human milk. The reliability of both methods was found to be very satisfactory.

In spite of this, such Eijkman tests appeared to have only limited usefulness because E. coli was found to be readily outgrown by other bacteria under extraenteral conditions; E. coli was therefore absent relatively often even from 1 ml samples of human milk which contained quite high numbers (i.e. > 103/ml) of other organisms of faecal origin. It is recommended, therefore, that too much reliance should not be placed on the outcome of Eijkman tests, especially when they give a negative result. The hygienic evaluation of foods should rather be based on the results of the simultaneous enumeration of three groups of organisms, namely E. coli, faecal types of Klebsiella (i.e. those which are urease positive) and Lancefield group D streptococci.

A striking result of this investigation was the occurrence in 69% of the human milk samples of 44° positive Achr. anitratus (B5W) in numbers from 10–5.6 times 103/ml. These bacteria were almost invariably found in samples which were E. coli negative; klebsiellae, many of which were Kb. oxytoca, were also found in such samples. The properties of these organisms and their ecological significance are discussed.
The Effect of Gamma Radiation on Some of the Organisms of Soil
Authors: Monib M. , Zayed M. N.
Published: March 2008

A loam soil of pH 8.0, supplemented with 1% of glucose, was irradiated with gamma rays at doses from 0.1 to 1 Mrad. Microbial counts were made immediately after irradiation, and after 15 and 30 days of incubation. The higher the dose, the greater the damage to micro‐organisms, but even the highest dose did not completely sterilize the soil. Azotobacters were killed by 1 Mrad and very much reduced in numbers by smaller doses. Clostridial spores were unaffected by 0.1 Mrad, and more resistant than azotobacters to larger doses. Streptomycetes developing on agar plates were more affected than bacteria at first, but during incubation the number of streptomycetes in the irradiated samples increased to more than the number in nonirradiated controls. Doses of irradiation that are too small to sterilize a soil evidently upset the equilibrium between bacteria and streptomycetes.
A Short Cycle Autoclaving Procedure
Authors: Jayne‐Williams D. J. , Lawes L. F.
Published: March 2008

Modifications to an autoclave are described which permit media in flasks or tubes to be cooled rapidly after sterilization at higher temperatures for shorter times than are generally used. Short cycle autoclaving has been shown to have a greater sporicidal effect but lesser chemical effect than conventional autoclaving.
A Species of Corynebacterium Isolated from Fermenting Cassava Roots
Authors: Collard P.
Published: March 2008

Summary: A species of Corynebacterium not described in the 7th edition of Bergey's Manual has been isolated from grated cassava (Manihot utilissima) root allowed to ferment for some days during the preparation of ‘gari’, a farinaceous food eaten in Nigeria. The organism ferments starch, dextrose, maltose, sucrose, salicin, xylose and arabinose with the production of acid only, and produces bright yellow colonies of a characteristic form on litmus‐lactose agar. It has been suggested that this organism, if accorded specific status, should be named Corynebacterium manihot.
The Occurrence of Bacillus coagulans with High Heat Resistance
Authors: Put Henriette M. C. , Wybinga S. J.
Published: March 2008

Summary: The heat resistance of spores of Bacillus coagulans strain Sp. 33, isolated from canned chopped spinach, has been determined. It appeared to be higher in 1/40 M phosphate than in 1/15 M phosphate and higher at pH 6°8 than at pH 6°0. In 1/40 M phosphate buffer of pH 6°8 the calculated D110 was 2°4 min. In chopped spinach of pH 6°2 the calculated D110 was 0°84 min. In addition a simple and reliable method of assessing the thermal resistance of micro‐organisms in thermal death time tubes is reported.
A Diagnostic Key for Identifying the Lactic Acid Bacteria of Vacuum Packed Bacon
Authors: Cavett J. J.
Published: March 2008

Summary: The lactic acid bacteria isolated from stored vacuum packed sliced bacon cured in fresh brine were divided into nine groups according to a simple diagnostic key. The key was developed to help in recognizing genera which were often morphologically similar.

The genera were Streptococcus (group D), Leuconostoc, Pediococcus and Lactobacillus (both hetero‐ and homofermentative), and all could grow at temperatures down to 10°. A ‘tetracoccus’ and a group of motile lactobacilli were also found. Some homofermentative groups were atypical and differed from species at present recognized. Intermediate forms were found among the heterofermenters.