bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of eight growth media upon fermentation profiles of ten anaerobic bacteria
Authors: Turton L.J. , Drucker D.B. , Hillier V.F. , Ganguli L.A.
Published: March 2008

A study was made of the influence of eight growth media upon the fermentation end‐product patterns obtained with ten species of anaerobes. Acidic and neutral end‐products of fermentation were analysed by gas chromatography and the results were examined statistically by computer. Differences in end‐product profile were at least as great between different media used to grow a single anaerobic species, as between different anaerobes grown in a single type of medium. When individual fermentation end‐products produced by a single anaerobe species were examined, statistically significant differences were found between different media for individual end‐products. It is concluded that standardisation of growth medium is essential in diagnostic laboratories concerned with identification of anaerobes with the aid of gas chromatography.
The microbial flora of herring fillets after storage in carbon dioxide, nitrogen or air at 2°C
Authors: Molin G. , Stenström Inga‐Maj , Ternström A.
Published: March 2008

Herring fillets from the Baltic Sea were stored in glass vessels in air, nitrogen or carbon dioxide (CO2) at 2°C and the microbial development was studied. The microbiological shelf‐life of the herring (the time to reach 107 organisms/g) was prolonged by a factor of 3.5 in CO2 as compared to air. The corresponding factor in nitrogen was 1.5. The microflora of fresh and spoiled herring was classified. The initial microflora was dominated by coryneforms, Flavobacterium spp., Moraxella‐like organisms and Pseudomonas spp. The spoilage‐flora in air (after 9 d) was dominated by Pseudomonas spp. and Moraxella‐like organisms, and in nitrogen (14 d) Enterobacteriaceae, Vibrionaceae and Lactobacillus spp. were dominant. Homofermentative Lactobacillus spp. were the only organisms isolated from fillets stored in CO2 (28 d). It was concluded that storing fresh fish in pure CO2 at low refrigeration temperatures is a method with industrial potential. The method (1) improves the microbiological stability and (2) reduces the microbiological health hazards of the fish.
Temperature and water activity minima for growth of spoilage moulds from meat
Authors: Lowry P.D. , Gill C.O.
Published: March 2008

Lowry, P.D. & Gill, C.O. 1984. Temperature and water activity minima for growth of spoilage moulds from meat. Journal of Applied Bacteriology56, 193–199.

Five species of fungi were isolated from mould spoilage on meat other than black spot. ‘White spot’ colonies yielded Chrysosporium pannorum or an Acremonium sp.; ‘whiskers’ colonies yielded Thamnidium elegans or Mucor racemosus, and blue‐green colonies yielded Penicillium corylophilum. Chrysosporium pannorum was moderately xerotolerant with a minimum growth temperature of — 5d̀C. The Acremonium sp. and P. corylophilum showed a similar level of xerotolerance but had a minimum growth temperature of — 2d̀C.Mucor racemosus was no more xerotolerant than many spoilage bacteria and did not grow below ‐ 1d̀C, but grew rapidly at 3d̀C and above. Thamnidium elegans grew at — 7d̀C on supercooled medium and an intrinsic minimum growth temperature of — 10d̀C was indicated. However, the low xerotolerance of this species precluded growth on frozen media below — 5d̀C. It seems therefore that — 5d̀C is the practical limiting temperature for mould growth on meat, and mould spoilage usually indicates that surfaces of freezer stored meats have approached and possibly exceeded 0d̀C.
Long‐term cultivation of certain rumen protozoa in a continuous fermentation system supplemented with sponge materials
Authors: Abe M. , Kurihara Y.
Published: March 2008

Abe, M. & Kurihara, Y. 1984. Long‐term cultivation of certain rumen protozoa in a continuous fermentation system supplemented with sponge materials. Journal of Applied Bacteriology56, 201–213.

Inert polyurethane‐sponge cubes were added to an ‘artificial rumen’ fermenter. With crushed barley as protozoal substrate this system maintained a population of Ento‐dinia in both substrate bags and sponge cubes for 64 d in numbers (1 times 106/ml) comparable with those found in vivo. This culture was more tolerant of variations in mechanical agitation and size and shape of substrate bags than a similar culture without the sponge cubes. The extent of protozoal sequestration, 2 h after feeding, on to the sponge cubes as well as on to acetone‐treated hay was evaluated. The bags of acetone‐treated hay and barley, and those of sponge cubes and barley could sequestrate the protozoa to the same extent as normal hay and barley. Based on the results of the short‐term experiments and those of the long‐term experiment with sponge cubes, a polyurethane‐sponge wall was added to the inside of the fermenter. This system maintained a varied protozoal population including large protozoa, holotrichs and Entodinia with a normal fermentation. The molar percentages of butyrate in the total volatile fatty acid (VFA) in each part of the fermenter with a sponge wall were higher than those in a fermenter without a sponge wall, suggesting that there was high protozoal activity related to the sponge wall. These results show that the introduction of the sponge wall to the fermenter produced an enlargement of the area for protozoal sequestration and a suitable micro‐habitat for the maintenance of Entodinia, large protozoa and holotrichs.
Detection of bacteriuria by bioluminescence: effect of pre‐analysis centrifugation of specimens
Authors: Nichols W.W. , Curtis G.D.W. , Johnston H.H.
Published: March 2008

Nichols, W.W., Curtis, G.D.W. & Johnston, H.H. 1984. Detection of bacteriuria by bioluminescence: effect of pre‐analysis centrifugation of specimens. Journal of Applied Bacteriology56, 247–257.

Three bioluminescence‐based, rapid methods of detecting significant bacteriuria were applied in parallel to 514 urine specimens. The results were compared with those of a quantitative pour plate viable count method, defined as positive if ≥ 105 c.f.u./ml of urine were observed. When adjusted to yield 21% falsely positive results the three rapid methods yielded 24%, 21% and 19% falsely negative results. If specimens with evidence of urethral or vaginal contamination were excluded (237 specimens remaining) the three methods yielded respectively 14%, 8% and 13% falsely negative results. A major source of disagreement between the bioluminescence‐based methods and quantitative culture thus appeared to be contaminated urine specimens.
The general utility of a glycerophosphate‐Tris buffered medium
Authors: Douglas J. , Dhillon J. , Smith S.E.
Published: March 2008

Douglas, J., Dhillon, J. & Smith, S.E. 1984. The general utility of a glycerophosphate‐Tris buffered medium. Journal of Applied Bacteriology56, 321–326.

An easily prepared medium, originally designed for the cultivation of lactic phages, has been found to have much wider application. Experience in its use over a ten year period with a range of physiologically diverse bacteria, for teaching and research, are summarized and evaluated.
A note on the presence of novel DNA species in the spoilage yeasts Zygosaecharomyces bailii and Pichia membranaefaciens
Authors: Painting K.A. , Kirsop Barbara
Published: March 2008

Painting, K.A. & Kirsop, Barbara, 1984. A note on the presence of novel DNA species in the spoilage yeasts Zygosaecharomyces bailii and Pichia membranaefaciens. Journal of Applied Bacteriology56, 331–336.

Two novel covalently closed circular DNA species of 5.4 and 6.0 kilobases were detected in strains of Zygosaecharomyces bailii with a rapid small scale isolation procedure. The 5.4 kb species was found in four strains and both species were found in three strains. A novel, covalently‐closed circular DNA species of 6.9 kb was detected in four of 12 strains of Pichia membranaefaciens. Plasmid DNA (2 μm) (that is CCC DNA of approximately 6 kb in Saccharomyces cerevisiae) was detected in 38 of 40 strains of Sacch. cerevisiae confirming reports of the widespread distribution of this plasmid.
A note on the formation of microbial polysaccharide from wheat straw decomposed in the absence of soil
Authors: Chapman S.J. , Lynch J.M.
Published: March 2008

Chapman, S.J. & Lynch, J.M. 1984. A note on the formation of microbial polysaccharide from wheat straw decomposed in the absence of soil. Journal of Applied Bacteriology56, 337–342.

The proportions of neutral sugars in fresh and decomposed wheat straw polysaccharide were similar, irrespective of the oxygen concentration used during breakdown. Polysaccharide extracted by hot water from the decomposed straw was composed mainly of galactose, glucose and mannose with smaller quantities of arabinose, xylose, rhamnose, fucose and ribose. The presence of these sugars indicates a mainly microbial origin for the polysaccharide but with some soluble hemi‐cellulose breakdown products. The polysaccharide precipitable with 70% (v/v) ethanol accounted for 0.5% (w/w) of the degraded straw. The extracted polysaccharide was shown to increase the aggregate stability of Mount St Helens volcanic ash.
A rapid chemical spot test for the detection of lactic acid as an indicator of microbial spoilage in preserved foods
Authors: Ackland M.R. , Reeder Julia E.
Published: March 2008

Ackland, M.R. & Reeder, J.E. 1984. A rapid chemical spot test for the detection of lactic acid as an indicator of microbial spoilage in preserved foods. Journal of Applied Bacteriology56, 415–419.

A rapid method for the detection of lactic acid in preserved foods has been developed, based upon a chemical spot test which does not require solvent extraction or derivatisation of the lactic acid in the sample. The test can be completed within 5 min and was shown to confirm microbial spoilage detected by cultural techniques in a range of preserved foods. In addition the test was able to indicate microbial spoilage in samples where cultural techniques failed because the spoilage organisms were dead. The test may not be appropriate for products which have a naturally high lactic acid content.
A note on the effect of host specific fermented milk on the coliform population of the neonatal rat gut
Authors: Cole C.B. , Fuller R.
Published: March 2008

Cole, C.B. & Fuller, R. 1984. A note on the effect of host specific fermented milk on the coliform population of the neonatal rat gut. Journal of Applied Bacteriology56, 495–498.

An adhering strain of Lactobacillus salivarius isolated from the intestine of a rat was used to ferment cow's milk fortified with whey protein and threonine. When the fermented milk was used to dose baby rats orally for the first three days of life, the numbers of coliform organisms in the gut decreased significantly.
A note on the heterofermentative Lactobacillus isolated from kefir grains
Authors: Marshall Valerie M. , Cole Wendy M. , Farrow J.A.E.
Published: March 2008

Marshall, V.M., Cole, W.M. & Farrow, J.A.E. 1984. A note on the heterofermentative Lactobacillus isolated from kefir grains. Journal of Applied Bacteriology56, 503–505.

Heterofermentative lactobacilli have been isolated from kefir grains obtained from four different sources. A number of these isolates ferment only L‐arabinose and gluconate and are similar to the species ‘Lactobacillus desidiosus’. The DNA of these isolates, however, have 85–109% homology with ‘L. caucasicus’ NCDO 190 which is now regarded as L. kefir. The relationship between these strains is discussed.
Characteristics of pathogenic non‐fluorescent (smooth) and non‐pathogenic fluorescent (rough) forms of Pseudomonas tolaasii and Pseudomonas gingeri
Authors: Cutri S.S. , Macauley B.J. , Roberts W.P.
Published: March 2008

Pseudomonas tolaasii and Ps. gingeri cultures isolated from naturally diseased mushrooms and cultures obtained from other workers were all observed to contain both smooth and rough colony forms. The smooth forms produced mucoid, non‐fluorescent, glistening opaque colonies with entire margins. The rough forms produced non‐mucoid, fluorescent, dull, translucent greenish‐yellow colonies with irregular margins. Smooth forms were observed to produce a toxin and were pathogenic to mushrooms, whereas rough forms did not produce toxin and were non‐pathogenic. Isolates of Ps. tolaasii were distinguishable from Ps. gingeri by various biochemical tests. In general, however, biochemical differences between the rough and smooth forms of each species could not be detected. Rough forms of Ps. tolaasii and Ps. gingeri remained stable in culture but smooth forms were unstable, tending to convert to rough forms at a very high rate.
Transfer of a host range plasmid from Rhizobium leguminosaum to fast‐growing bacteria that nodulate soybeans
Authors: Ruiz‐Sainz J.E. , Chandler M.R. , Jimenez‐Diaz R. , Beringer J.E.
Published: March 2008

The Rhizobium leguminosarum host range plasmid pJB5JI was transferred to three fast‐growing bacterial strains able to nodulate soybeans. These strains, isolated in China, contained plasmids and were able to transfer pJB5JI back to R. leguminosarum. Soybean strains carrying pJB5JI elicited early stages of nodule development on peas.
An affinity technique for the isolation of Clostridium perfringens type C from man and pigs in Papua New Guinea
Authors: Lawrence G. , Brown R. , Bates J. , Saul A. , Davis M. , Spark R. , Anian G.
Published: March 2008

Necrotising enteritis caused by Clostridium perfringens type C (CwC) is an important cause of morbidity and death in highland regions of Papua New Guinea (PNG) and the organism is readily isolated from clinical cases. Although detected in fluorescent antibody stains of faecal cultures, CwC has previously only once been isolated from normal people or from pigs in PNG. The difficulty results from the greater numbers of the much more common Cl perfringens type A (CwA) which is morphologically and culturally indistinguishable from CwC. Separation of CwC from the more numerous CwA has been achieved by utilising their antigenic dissimilarity. Silicate beads covered with specific antibody to CwC added to a mixed culture bound CwC cells while most of the unbound cells were washed away. When the beads were plated out type C organisms were recovered. In laboratory tests CwC was isolated from mixtures with CwA where the type A organisms predominated by one million to one. With this system type C organisms have been isolated from human and pig faeces from PNG.
Photodynamic inactivation of Bacillus subtitis spores
Authors: Abad‐Lozano J.L. , Rodriguez‐Valera F.
Published: March 2008

The effect of strong visible light on spores of Bacillus subtilis has been studied. With the illumination conditions used, spores were killed exponentially and viability decreased to less than 13% survivors after 24 h. This decrease did not take place when the cells were kept under strictly anaerobic conditions. The killing is, therefore, attributable to a photodynamic effect. The presence in the medium of exogenous photosensitizers did not increase the effect of light and this is attributable to the impermeability of spores to these agents. Once germinated, the spores were killed at a much faster rate, even when outgrowth was stopped. The highest sensitivity was reached 90 min after onset of outgrowth.
Changes in metabolism of the rumen bacterium Streptococcus bovis H13/1 resulting from alteration in dilution rate and glucose supply per unit time
Authors: Silley P. , Armstrong D.G.
Published: March 2008

Streptococcus bovis H13/1 was grown in a glucose‐limited chemostat. A concomitant increase in dilution rate and glucose supply per unit time caused both an increase in lactate production per mole of glucose fermented and a linear increase in growth yield over the dilution rate range 0.052 to 0.141/h. When the dilution rate was increased with no change in glucose supply per unit time there was a reduction in lactate production and an increase in that of acetate and ethanol coinciding with a non‐linear increase in growth yield. YgluMax= 38.6 and a maintenance coefficient, ms= 0.290 mmol/l glucose/g cells/h were calculated. The results also suggested an interaction between the formate and CO2 pools.
The influence of scald water pH on the death rates of Salmonella typhimurium and other bacteria attached to chicken skin
Authors: Humphrey T.J. , Lanning D.G. , Leeper Denise
Published: March 2008

Factory trials where scald tank water was maintained at pH 9.0± 0.2 showed that compared with the usual system of scalding when the water is at pH 6.0 for much of the working day the bacterial counts on carcases post scalding and plucking were significantly lower. In laboratory experiments, attached Salmonella typhimurium and the naturally occurring skin flora were found to be killed significantly more quickly in water at pH 9.0±0.2.
The rationale and a computer evaluation of a gamma irradiation sterilization dose determination method for medical devices using a substerilization incremental dose sterility test protocol
Authors: Davis K.W. , Strawderman W.E. , Whitby J.L.
Published: March 2008

The experimental procedure described is designed to allow calculation of the radiation sterilization dose for medical devices to any desired standard of sterility assurance. The procedure makes use of the results of a series of sterility tests on device samples exposed to doses of radiation from 0.2 to 1.8 Mrad in 0.2 Mrad increments. From the sterility test data a 10‐2 sterility level dose is determined. A formula is described that allows a value called DS Mrad to be calculated. This is an estimate of the effective radiation resistance of the heterogeneous microbial population remaining in the tail portion of the inactivation curve at the 10‐2 dose and above. DS Mrad is used as a D10 value and is applied, in conjunction with the 10‐2 sterility level dose, to an extrapolation factor to estimate a sufficient radiation sterilization dose. A computer simulation of the substerilization process has been carried out. This has allowed an extensive evaluation of the procedure, and the sterilization dose obtained from calculation to be compared with the actual dose required. Good agreement was obtained with most microbial populations examined, but examples of both overdosing and underdosing were found with microbial populations containing a proportion of organisms displaying pronounced shoulder inactivation kinetics. The method allows the radiation sterilization dose to be derived from the natural resistance of the microbial population to gamma sterilization.
Interaction of some polyhexamethylene biguanides and membrane phospholipids in Escherichia coli
Authors: Broxton P. , Woodcock P.M. , Heatley F. , Gilbert P.
Published: March 2008

The interaction between some polyhexamethylene biguanides and the cell envelope of Escherichia coli has been investigated. An amine‐ended dimer, (AED, n= 2), a polydisperse mixture (ICI plc) available as the active ingredient of Vantocil IB, (PHMB, n= 5.5), and a high molecular weight fraction, (HMW, n=≧ 10) of PHMB were used. The sensitivity of batch cultures depleted of magnesium (M‐dep), phosphorus (P‐dep) or glycerol (C‐dep) towards the biocides was assessed by monitoring the rate and extent of potassium ion leakage. P‐dep suspensions were particularly resistant to all these agents and possessed less than half the quantity of phospholipid of other cell types. This was compensated for by a proportionate increase in fatty acid and neutral lipid content of the cells. The reduction in phospholipid content was accounted for by decreases in phosphatidylglycerol (PG) and phosphatidylethanolamine (PE). Diphosphatidylglycerol (DPG) and phosphatidylserine (PS) content of the cultures remained unaffected by the depleting nutrient. Fourier‐transform n.m.r. spectroscopy was used to study proton nuclei during the interaction of HMW, AED and PHMB with various phospholipid‐vesicle preparations. The results strongly suggest that the biocides acted preferentially on the acidic phospholipids PG and DPG, rather than towards PE or PS. Resistance of P‐dep cultures therefore reflected reductions in PG content. A molecular basis for the interaction of these compounds and membranes is proposed.
A note on the survival of bacteria in cryoprotectant medium at temperatures above 0°C
Authors: Pell Patricia A. , Sneath P. H. A.
Published: March 2008

Many bacteria can survive for days or weeks at temperatures of 4° or 22°C in medium containing 15% (v/v) glycerol as a cryoprotectant. This observation suggests that breakdown of refrigeration for a short time may not be a serious danger to survival of cultures stored frozen in such media.
The enumeration of Bacteroides fragilis group organisms from sewage and natural waters
Authors: Allsop K. , Stickler D.J.
Published: March 2008

Allsop K. & Stickler D. J. 1984. The enumeration of Bacteroides fragilis group organisms from sewage and natural waters. Journal of Applied Bacteriology56, 15–24.

A membrane filtration technique has been developed for the enumeration of Bacteroides fragilis group (BFG) organisms from sewage and natural waters. The method uses the agar medium of Wilkins and Chalgren supplemented with gentamicin. penicillin, aesculin and ferric ammonium citrate. Membrane filters with 0.22 μm pores were significantly more efficient than those with 0.45 μm pores in the isolation of BFG. A preliminary incubation period of 4 h at 30d̀C prior to 44 h at 37d̀C yielded significantly higher numbers of BFG than direct incubation at 37d̀C for 48 h.
Role of micro‐organisms in biltong flavour development
Authors: Prior B.A.
Published: March 2008

Prior, B.A. 1984. Role of micro‐organisms in biltong flavour development. Journal of Applied Bacteriology56, 41–45.

When biltong, a dried salted meat product, is prepared from beef, micro‐organisms are able to proliferate freely and counts of 9.8 times 104 to 3.8 times 107/g are observed. Treating the meat with four antibiotics before production of the biltong restricted microbial growth, yet a taste panel was unable to distinguish between biltong containing high and low numbers of micro‐organisms. No significant difference in the free amino acid and free fatty acid content of biltong; prepared with and without antibiotics was detected although there were significant increases in these compounds during biltong production. These results suggest that micro‐organisms are not involved in the development of biltong flavour and microbial inhibitors may thus be added to the meat as a preservative agent without affecting the development of the biltong flavour, taste and aroma.
Evaluation of a cup scrub technique for quantification of the microbial flora on bovine skin
Authors: Lloyd D.H.
Published: March 2008

Lloyd, D.H. 1984. Evaluation of a cup scrub technique for quantification of the microbial flora on bovine skin. Journal of Applied Bacteriology56, 103–107.

A cup‐scrub technique devised for sampling the human skin surface microfiora was evaluated in cattle. Scrub samples from bovine skin contained clumps of squames and bacterial microcolonies which were progressively broken down by shaking. This was accelerated in the presence of ballotini beads but aggregations of bacteria were still present after prolonged agitation. Vigorous shaking, particularly with beads, decreased the viability of the bacteria and optimum viable counts were obtained after manual shaking for half a minute. Immersion in buffered detergent, wash and diluting fluids for up to 2 h promoted release of bacteria from micro‐colonies but decreased the viability of aerobic and anaerobic pleomorphic rods and a Bacillus strain. There was no significant effect on strains of Micrococcaceae. Prolonged exposure of bacteria from scrub samples to these fluids can thus lead to both quantitative and qualitative alterations in the counts: obtained, although these effects may be masked by the continuing release of bacteria from microcolonies. The cup‐scrub technique provides a convenient means of quantifying changes in the bovine skin microfiora but results obtained from different studies should only be compared if closely similar techniques are used.
The effect of suspended particulate material on cyanobacteria—cyanophage interactions in liquid culture
Authors: Barnet Yvonne M. , Daft M.J. , Stewart W.D.P.
Published: March 2008

Barnet Yvonne M., Daft, M.J. Stewart, W.D.P. 1984. The effect of suspended particulate material on cyanobacteria‐cyanophage interactions in liquid culture. Journal of Applied Bacteriology56, 109–115.

The effect of the lytic phage LPP‐DUN 1 on the cyanobacterium Plectonema boryanum has been investigated in batch and in continuous cultures in the presence and absence of silt. In batch culture Plectonema without added phage grew normally; the presence of phage caused rapid lysis of the cyanobacterium and the addition of silt prevented lysis by the phage. In continuous culture the numbers of cyanobacterial cells and phage particles oscillated in a reciprocal manner, but the addition of silt damped down the oscillations in Plectonema biomass without decreasing the numbers of phage particles isolated from the cultures. The presence of silt thus appears to protect the cyanobacterium from lysis by phage, although the total numbers of phage particles are relatively unaffected by the silt, at least in the short‐term.
The ability of campylobacter media supplements to neutralize photochemically induced toxicity and hydrogen peroxide
Authors: Bolton F.J. , Coates D. , Hutchinson D.N.
Published: March 2008

Bolton, F.J. Coates D. & Hutchinson, D.N. 1984. The ability of campylobacter media supplements to neutralize photochemically induced toxicity and hydrogen peroxide. Journal of Applied Bacteriology56, 151–157.

Nutrient agar plates stored in light and air for 48 h became inhibitory for Campylobacter jejuni, C. coli and nalidixic acid‐resistant, therrnophilic campylobacter (NARTC) strains. All five campylobacter test strains showed > 5 log reduction in counts on media which had been stored in light and air. Media stored in the dark and/or in a reduced atmosphere did not become inhibitory and supported the growth of campylobacters. Ferrous sulphate, sodium pyruvate, blood, charcoal or sodium metabisulphite, compounds frequently used as supplements in campylobacter media, were added to nutrient agar prior to storage of media in light and air. All additives except sodium metabisulphite prevented the accumulation of photochemically generated toxic oxygen derivatives and allowed growth of test strains. In qualitative tests to determine the ability of supplements to neutralize hydrogen peroxide, blood was the most active, charcoal and sodium pyruvate slightly less active and ferrous sulphate and sodium metabisulphite the least active. The results of this study confirm that supplements in campylobacter media act as quenching or detoxifying agents and not as enrichment factors.
A note on the isolation of auxotrophic mutants of Rhizobium japonicum
Authors: Zlotnikov K.M. , Chatuev B.M. , Khmelnitsky M.I.
Published: March 2008

Zlotnikov K.M. Chatuev B.M. khmelnitsky, M.I. 1984. A note on the isolation of auxotrophic mutants of Rhizobium japonicum. Journal of Applied Bacteriology56, 173–174.

Several different stable auxotrophic mutants of Rhizobium japonicum were isolated following NG mutagenesis. It was found that NG mutagenesis of the rhizobia was most efficient at pH 70.
A note on a modified membrane‐Bovis agar for the enumeration of Streptococcus bovis by membrane filtration
Authors: Oragui J.I. , Mara D.D.
Published: March 2008

Oragui, J.I. Mara, D.D.1984. A note on a modified membrane‐Bovis agar for the enumeration of Streptococcus bovis by membrane filtration. Journal of Applied Bacteriology56, 179–181.

A modified membrane‐Bovis agar, containing a reduced quantity of sodium azide, for the isolation and enumeration of Streptococcus bovis is described and evaluated. Higher counts, with larger colonies, were obtained from water and sewage samples with this medium than with the original formulation.
An assessment of methods for measuring volumes of planktonic bacteria, with particular reference to television image analysis
Authors: FRY J.C. , DAVIES A.R.
Published: March 2008

Several methods for measuring volumes of planktonic bacteria were compared. The eyepiece micrometer grossly overestimated cell width (47–65%) and hence volume (73%). Shrinkage occurred with scanning electron microscopy, so volumes were underestimated by about 77%. All the other methods gave similar results (mean volume = 0.133 µm3). The optimum technique was to filter acridine orange stained bacteria through polycarbonate membrane filters (0.2 µm) which were photographed with epifluorescence microscopy using Kodak Tri‐X pan film. We recommend that volumes are estimated from individual area and perimeter measurements of at least 200 bacteria with a Quantimet 800 or Q10 image analyzer.
Book Reviews
Authors: YOUNG T.W.
Published: March 2008

Book reviewed in this article:

YEASTS: CHARACTERISTICS AND IDENTIFICATION (1983). J.A. Barnett, R.W. Payne & D. Yarrow. 812 pp. Cambridge: The University Press. pD75.00.
A note on the selection of a non‐adhesive methylotrophic bacterium for use in continuous culture studies
Authors: LEGAN J.D. , OWENS J.D.
Published: March 2008

A simple technique, based on the use of Microtitre plates, was used to select a non‐adhesive variant clone of a methylamine‐utilizing bacterium. The variant clone grew in continuous culture without visible wall growth and with only very slight floe formation, whereas the parental strain grew with very heavy wall growth and a high proportion of the suspended cells present as flocs.
Enumeration of rhizobia by enzyme‐linked immunosorbent assay (ELISA)
Authors: NAMBIAR P.T.C. , ANJAIAH V.
Published: March 2008

The use of the enzyme‐linked immunosorbent assay (ELISA) to enumerate rhizobia in peat carrier and in soil has been investigated. The ELISA technique takes less time than the conventional plant infection technique often used to enumerate rhizobia present in the presence of other micro‐organisms. A minimum of 102–103 cells are required for a detectable ELISA reaction, limiting the use of this technique when the number of rhizobia is low.
A note on gentamicin susceptibility testing: the validity of the MS‐2 system and Rosco Neosensitabs agar diffusion
Authors: CAEKENBERGHE D.L. VAN , ROOSBROECK R.J. VAN
Published: March 2008

The MS‐2 automated system was compared with Rosco Neosensitabs agar diffusion for the gentamicin susceptibility of a group of 267 organisms isolated from clinical material. With Rosco Neosensitabs agar diffusion agreement with reference minimal inhibitory concentrations was 98.5%, while with the MS‐2 system it was 100% if calcium and magnesium‐supplemented MS‐2 broth was used.
Discontinuous polyacrylamide gel electrophoresis of cell wall proteinase from variants of Streptococcus lactis
Authors: CLIFFE A. J. , LAW B.A.
Published: March 2008

An electrophoretic procedure has been developed for the separation of plasmid‐coded cell wall proteinases from Streptococcus lactis NCDO strain 712. The pH and casein concentration within the electrophoresis rod during detection is more closely defined than in existing methods. The incubation conditions used with casein, (approximately pH 7 and 30dEC) may be suitable for the detection of a wider range of proteinases from other sources. Four proteinase bands present in the cell wall have been detected in milk grown cells, but only two in those previously grown in a broth medium. No cell wall proteinases were detected in a proteinase deficient variant.
Protective effect of casein toward Salmonella typhimurium in acid‐milk
Authors: RUBIN H.E.
Published: March 2008

Lactic acid is the inhibitory agent in yoghurt responsible for the inhibition of Salmonella typhimurium. Casein, however, may exert a protective effect toward the survival of the salmonella in acid‐milk products. Salmonella typhimurium was found to die‐off 21.2% more rapidly in 18‐h yoghurt‐whey than in 18‐h yoghurt at 37 C with a pH of 3.85 and 1.42% lactic acid. When casein was added to yoghurt‐whey, the die‐off rate of the salmonellas was reduced to that found in yoghurt. The rate remained unchanged when 4.8% sodium caseinate was added to the whey. When 0 to 14% casein was added to the acid‐whey the die‐off rate changed from 9.7 to 24.0 min/log reduction of cells, respectively. There was a direct correlation between the increase in casein concentration and length of survival of the salmonellas. At a pH of 3.85, 4.2 or 4.5, the die‐off rate was 6.5, 13.0 or 40 min/log reduction of cells in milk containing 1.42% lactic acid, and was 4.0, 10.0 or 33.3 min/log reduction, respectively, in whey with 1.42% lactic acid. Thus, the protective effect of casein toward Salm. typhimurium incieased as the pH increased. This indicated that casein exerts a protective effect on Salm. typhimurium in acid dairy products and the degree of protection depends on the casein concentration, the form of the casein molecule and the pH.
A micro‐chamber for continuous microscopic monitoring of anaerobic bacteria
Authors: ELEY A. , GREENWOOD D. , O'GRADY F.
Published: March 2008

A recently developed apparatus is described that allows continuous microscopic monitoring of bacteria grown in anaerobic conditions. Four species of Bacteroides were tested using this equipment and normal and reproducible growth rates were obtained in all cases.
Production of ethanol from infant food formulas by common yeasts
Authors: BIVIN W.S. , HEINEN B.N.
Published: March 2008

Four common yeasts (Candida albicans, Candida tropicalis, Torulopsis glabrata and Saccharomyces cerevisiae) were combined with five infant food formulas and/or supplements (Isomil, Nutramigen, 5% glucose, Coca Cola and Similac) and incubated at 37°C. Gas chromatography was used to measure ethanol production after 24 and 48 h incubation. The quantities of ethanol produced suggest a possible explanation for patients exhibiting the ‘Auto‐Brewery Syndrome’ and raises interest in the role auto‐produced ethanol could have in explaining the etiology of Sudden Infant Death.
A note on microbial spoilage of sheep meat at ambient temperature*
Authors: RAO D. NARASIMHA , SREENIVASAMURTHY V.
Published: March 2008

Shelf‐life and microbial spoilage of sheep carcass meat at ambient temperature under commercial conditions were studied. The initial bacterial count of carcasses ranged 5.6–5.8 log/cm2. Staphylococcus spp. (48%) predominated in the initial microflora of carcasses followed by Micrococcus spp. (19%) and Escherichia spp. (12%). Microbial spoilage of carcasses occurred around 20 h when the bacterial count reached 8.0–9.0 log/cm2. Thus the shelf life of carcasses at ambient temperature was 19 h. The predominant micro‐organisms at the time of spoilage were Escherichia and ‘Acinetobacter‐like’ organisms. It was also observed that Enterobacter, Pseudomonas and Staphylococcus spp. could form a major part of the final flora. The presence of Escherichia and Staphylococcus spp. in higher percentages on the surface of carcasses at the time of spoilage presents the scope for health hazards.
Search for acid‐fast bacilli in bottled mineral waters
Authors: CAROLI G. , LEVRE EGLE , ARMANI G. , BIFFI‐GENTILI S. , MOLINARI G.
Published: March 2008

Samples of bottled mineral water sold in Italy in accordance with the law on microbiological standards were examined for the presence of acid‐fast bacilli. Eighty‐four samples were tested, 11 with added carbon dioxide and 73 without. Acid‐fast bacilli were found in 1 of the former samples and in 8 of the latter, a total of 10.7%. The mycobacterial count was always very low (2–3 cfu/litre) except for one sample which showed large numbers of Mycobacterium sphagni. This finding was not confirmed in two following samplings of the same water. The other acid‐fast bacilli isolated were: M. gordonae (four strains), M.flavescens (one strain), M. phlei (one strain) and Nocardia sp. (two strains) in two samples of different water. These bacilli are not thought to be a normal component of the waters but are the result of incidental contamination. The risk of infection from drinking such waters can be regarded as irrelevant in hospitalized or immunologically compromised subjects who face a greater risk when using tap water for drinking or washing.
Predicting the shelf life of packaged fish from conductance measurements
Authors: GIBSON D.M.
Published: March 2008

The bacteriological quality of chill‐stored packaged fish was determined rapidly from automated conductance assays and conventionally by routine methods. These results together with those from organoleptic assessment were incorporated into a predictive model to estimate the remaining shelf life of the products at any given temperature using recent theories concerning time‐temperature integration functions.
Pectin degradation in plant material by Leuconostoc mesenteroides
Authors: JUVEN B.J. , LINDNER P. , WEISSLOWICZ H.
Published: March 2008

A strain of Leuconostoc mesenteroides that was able to reduce the viscosity of tomato juice serum and of a growth medium containing pectin was isolated and the pectolytic activity of its cell‐free culture supernatant (CFS) was studied. In vitro tests showed that the CFS was active on high methoxyl pectin but almost inactive on low methoxyl pectin and polygalacturonic acid. It was most active in the pH range 4mD5–5mD5 and had no detectable pectinesterase activity. In vivo tests showed that the CFS degraded pectin in the walls of tomato fruit cells and caused degradation of cucumber fruit tissues.
In vivo activity of nifurzide and nifuroxazide in intestinal bacteria in man and gnotobiotic mice
Authors: LEONARD FLORENCE , ANDREMONT A. , TANCREDE C.
Published: March 2008

Although Gram‐negative enteropathogenic bacteria are the target strains of nifurzide and nifuroxazide treatments, neither drug affected faecal counts of in vitro‐susceptible Enterobacteriaceae in healthy volunteers. This absence of activity was shown to be due to the poor solubility of the drugs tested. Therefore, effect of high doses of nifurzide was investigated in gnotobiotic mice. Activity against in vitro susceptible enteropathogens was then observed. Normal bacterial cells were replaced in the faeces by elongated, nonseptate and unflagellated mutants. Moreover, the resistance to colonization by enterotoxigenic Escherichia coli and Shigella flexeri of an anaerobic flora of human origin was sharply decreased.
A new apparatus for continuous cultivation of bacterial plaque on solid surfaces and human dental enamel
Authors: NOORDA W.D. , PURDELL‐LEWIS D.J. , KONING W. DE , MONTFORT ANNEKE M.A.P. VAN , WEERKAMP A.H.
Published: March 2008

A new apparatus for the continuous cultivation of mono and mixed bacterial plaque on solid surfaces is described. The features are: (i) easy preparation and handling; (ii) freedom from technical problems and microbial contamination; (iii) self‐sufficient for periods of up to 56 d; (iv) 12 samples are taken simultaneously; (v) programmable supply inlet. Experiments were performed with Streptococcus mutans C 67–1 for mono bacterial inoculation and in combination with Veillonella alcalescens V‐1 for mixed bacterial inoculations. The results showed that the controlled conditions and versatility of the apparatus make possible the study of plaque‐development and lesion production on a time‐dependent basis. It is concluded that the apparatus is suitable for a wide range of dental and non‐dental applications.
Resident population of Xanthomonas campestris pv. malvacearum on cotton leaves: a source of inoculum for bacterial blight
Authors: MOFFETT MELD A L. , WOOD BARBARA A.
Published: March 2008

Xanthomonas campestris pv. malvacearum was transmitted from infested seed to the cotyledons of cotton cv. Deltapine 61 seedlings at 28°C and relative humidities (RH) of 90% or 73%. A resident population was present on the first and second true leaves but not on the third true leaf of plants at either RH. There were smaller numbers of resident bacteria on fewer leaves of plants at the lower RH than on plants at the higher RH. Cotton plants grown from infested seed at 25°C and 30°C and incubated at 100% RH at different stages of growth developed bacterial blight on leaves that were in bud or partly expanded when incubated. Resident cells of this pathogen can thus invade susceptible leaves when conditions are favourable for infection. Bacterial blight developed on more plants at 30°C than at 25°C. In a field trial, X. campestris pv. malvacearum transmitted from seed was present as resident bacteria on the third leaf from the growing point during the vegetative development of the plant. Resident bacteria, which infected young leaves during rainy periods, were isolated from the bacterial blight lesions which subsequently developed.
The influence of water on the resistance of spores to inactivation by gaseous ethylene oxide
Authors: DADD A.H. , TOWN MARGARET M. , MCCORMICK KATHLEEN E.
Published: March 2008

Standardized conditions for exposure to ethylene oxide were used to evaluate the resistance of spores dried for various times at different relative humidities and temperatures. Spores dried under conditions of high humidity exhibited low resistance to the sterilant, the resistance increasing as the relative humidity (RH) was decreased. Increasing the temperature of drying amplified this effect by reducing the time required for equilibration to a specific RH. Spores dried over a desiccant at 37°C showed a slight rise followed by a fall in resistance. Spores maintained under these conditions for a long period of time increased in resistance. Spores rapidly dried by exposure to low RH, over a desiccant or at elevated temperature, dried unevenly resulting in a heterogeneous population with respect to ethylene oxide resistance. This was expressed as non‐logarithmic survivor curves. The initial vacuum drawn influences resistance. The resistance of spores dried on aluminium foil increased as the pressure was reduced. The rate at which the pressure was reduced had little effect on resistance, except with highly desiccated spores. Dried spores held at different reduced pressures with humidification, showed no differences in resistance. The implications of these findings in relation to the operation of ethylene oxide sterilization cycles and the preparation and use of biological monitors is discussed.
The effect of bacteria on the solubilization of silica in diatom frustules
Authors: Patrick Sheila , Holding A.J.
Published: March 2008

Patrick, Sheila & Holding, A.J. 1985. The effect of bacteria on the solubilization of silica in diatom frustules. Journal of Applied Bacteriology59, 7–16.

Natural bacterial populations in samples of water from Loch Leven and Lough Neagh increased the rate of solubilization of frustule silica from an axenic Cyclotella meneghiniana culture, compared with sterile autolysis, at 25d̀C. In the inoculated cultures 50–60% of the silica was solubilized over a period of 30 d. Bacterial populations in Loch Leven water also enhanced the solubilization of silica from non‐axenic cultures of Asterionella formosa, Tabellaria flocculosa, Navicula pellicu‐losa and C. meneghiniana, compared with control cultures sterilized with mercuric chloride. Similar results were obtained with Lough Neagh populations incubated with A. formosa. In comparison with untreated cells, the treatment of diatom cells with ultra‐sonication did not increase the release of silica. Pure cultures of bacteria from Loch Leven water enhanced the release of silica from non‐axenic A. formosa and axenic C. meneghiniana compared with sterile control treatments. The variation in the ability of cultures to solubilize the frustule silica appeared to be related to their potential to produce hydrolytic enzymes. Natural populations of Loch Leven and Lough Neagh water bacteria and certain bacterial cultures caused the diatoms to aggregate, which did not enhance the release of silica.
A note on the characterization of an estuarine microbial community enriched with the herbicide Fenuron
Authors: Minney Susan F. , Parkes R.J. , Bull A.T.
Published: March 2008

Minney, S.F., Parkes, R.J. & Bull, A.T. 1985. A note on the characterization of an estuarine microbial community enriched with the herbicide Fenuron. Journal of Applied Bacteriology59, 17—22.

A stable, five‐membered estuarine microbial community was enriched in the presence of 1,1 dimethyl‐3‐phenylurea (Fenuron), phenylurea and aniline. At a dilution rate of 0μD01/h in the chemostat, partial aniline utilization occurred and the rate increased with dilution rate. At the higher dilution rates the phenylurea component was also utilized. At a dilution rate of mD015/h in a fluidized bed system, complete removal of both aniline and phenylurea occurred. There was no evidence of Fenuron degradation under any of the conditions examined. The importance of the use of heterogeneous culture conditions in the laboratory is discussed.
Growth kinetics of mixed culture in salmonella enrichment media
Authors: Rhodes P. , Quesnel L.B. , Collard P.
Published: March 2008

Rhodes, P., Quesnel, L.B. & Collard, P. 1985. Growth kinetics of mixed culture in salmonella enrichment media. Journal of Applied Bacteriology59, 231–237.

A technique for investigating the kinetics of salmonella enrichment is reported. Its use with four enrichment media (Rappaport' medium, Muller‐Kauffmann tetra‐thionate broth (MKT) tetrathionate broth and selenite F) is described and the effect of elevated temperature on the growth kinetics shown. Rappaport' medium at 37d̀C and MKT at either 37d̀C or 42d̀C were far superior to selenite F and tetrathionate broth in their selective properties and, with the exception of Rappaport' medium, the use of elevated temperature increased the selectivity of the media.
Influence of mixed culture conditions on yeast‐wall hydrolytic activity of Bacillus circulans WL‐12 and on extractability of astaxanthin from the yeast Phaffia rhodozyma
Authors: Okagbue R.N. , Lewis M.J.
Published: March 2008

Okagbue, R.N. & Lewis, M.J. 1985. Influence of mixed culture conditions on yeast‐wall hydrolytic activity of Bacillus circulans WL‐12 and on extractability of astaxanthin from the yeast Phaffia rhodozyma. Journal of Applied Bacteriology59, 243–255.

In mixed culture Bacillus circulans WL‐12 hydrolysed cell walls of Phaffia rhodozyma and rendered astaxanthin extractable from the yeast. pH control was critical to survival and lytic activity of the bacillus; the optimum range was 6.2–6.8. The optimum range of temperature was 20–24d̀C. Glucose (1–2%) was efficient in minimizing catabolite repression of the lytic enzyme complex of the bacillus. Slow‐feeding of glucose improved ultimate yields of lytic enzyme but did not acclerate yeast cell wall modification. A relatively high inoculum level of B. circulans accelerated modification of P. rhodozyma in the mixed culture: when the bacterial inoculum was four times that of the yeast, over 80% of total astaxanthin was extractable in 48 h. High bacterial inoculum size also stimulated yeast autolysis and necessitated early harvest of the mixed culture. Results obtained in shake flasks were duplicated in 5‐litre fermentors and suggest that the mixed culture has potential industrial value for producing a biomass containing biologically‐available astaxanthin. Extractability of astaxanthin was also achieved when mixed culture filtrate was incubated with pure cultured Phaffia cells. When suitably fortified with nutrients, the filtrate also supported simultaneous yeast growth and modification of the yeast cell walls. A scheme incorporating mixed culture with B. circulans WL‐12 and re‐use of culture filtrate has been proposed for enzymatic processing of Phaffia rhodozyma for inclusion in animal diets.