bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiology of bruised tissue
Authors: Gill C O , Penney N
Published: January 2020

No significant differences could be found in the microbial quality of bruised and unbruised tissue provided that the two types of tissue were treated identically. This suggests that there is no good reason for the condemnation of bruised tissue, which could well be used in manufactured products.
Mineralization Capacity of Bacteria and Fungi from the Rhizosphere-Rhizoplane of a Semiarid Grassland
Authors: Nakas J. P. , Klein D. A.
Published: January 2020

A radiotracer glucose mineralization assay was used with streptomycin and actidione to monitor the relative seasonal contributions of bacteria and fungi to mineralization processes in soils derived from the rhizosphere-rhizoplane zone of plants from a shortgrass prairie ecosystem. Bacteria played a major role in glucose mineralization in both the rhizosphere and rhizoplane. These results indicate that the bacteria may play a greater role in glucose mineralization processes in the rhizosphere and rhizoplane zones of a semiarid grassland than would be assumed, based on available biomass estimates. This technique appears to be valuable for determining bacterial versus fungal contributions to glucose mineralization in the rhizosphere and rhizoplane and may be useful for measuring the decomposition of other more complex substances in this zone of intense microbial activity.
Comparison of Effects of Sublethal Microwave Radiation and Conventional Heating on the Metabolic Activity of
Staphylococcus aureus
Authors: Dreyfuss M. S. , Chipley J. R.
Published: January 2020

This study was conducted in an attempt to characterize some of the effects of sublethal microwave radiation on cells of
Staphylococcus aureus.
Cultures were exposed to microwave radiation for 10, 20, 30, and 40 s. The effects of a conventional heat treatment were also compared by placing flasks containing cultures in a boiling water bath for the amount of time required to reach temperatures equivalent to those found in cultures exposed to microwave radiation. Control, microwave-treated, and conventionally heat-treated cultures were centrifuged, pellets were resuspended in distilled water, and the resulting suspensions were passed through a French pressure cell. Cell lysates and walls were then isolated and assayed for enzymatic activity. Thermonuclease production was also determined at various levels of exposure of cells to microwave radiation. Activities of malate and α-ketoglutarate dehydrogenases, cytochrome oxidase, and cytoplasmic adenosine triphosphatase were higher in microwave-treated cells than in control cells. Membrane adenosine triphosphatase, alkaline phosphatase, and lactate dehydrogenase activities were unaffected when cells were exposed to microwave radiation. The activity of glucose-6-phosphate dehydrogenase was decreased by exposure of cells to microwave radiation. In conventionally heated cells, activities of glucose-6-phosphate and malate dehydrogenases and cytoplasmic adenosine triphosphatase increased activities of α-ketoglutarate and lactate dehydrogenases decreased, and alkaline phosphatase activity remained unaffected. Increased levels of thermonuclease activity were observed when cells were exposed to microwave radiation for 10 or 20 s. Data indicate that microwave radiation affects
S. aureus
in a manner which cannot be explained solely by thermal effects.
Accelerated procedure for the enumeration and identification of food-borne Staphylococcus aureus
Authors: Lachica R V
Published: January 2020

A procedure was developed for accelerating to 29 h the enumeration and identification of both healthy and stressed cells of Staphylococcus aureus in foods. Baird-Parker agar medium was incubated for 24 h; S. aureus was identified within 5 additional h by using a simplified thermonuclease test.
Phenanthrene Biodegradation in Freshwater Environments
Authors: Sherrill T. W. , Sayler G. S.
Published: January 2020

Phenanthrene, a low-molecular-weight polycyclic aromatic hydrocarbon, was incubated with water samples from various reservoir systems in Tennessee to evaluate the potential for significant polycyclic aromatic hydrocarbon degradation by the indigenous microbial populations. Biodegradation was assessed by comparison of total polycyclic aromatic hydrocarbon substrate recovery in degradation flasks relative to sterile control flasks. During 1977 field studies, the mean phenanthrene biodegradation was approximately 80% after a 4-week incubation. Within a given habitat, 45% of the total variability in phenanthrene biodegradation was attributable to the physical, chemical, and microbiological site characteristics examined. Polycyclic aromatic hydrocarbon degradation was directly related to the historical environmental pollution of the sampling sites examined, the length of biodegradation assessment, temperature, and the molecular size of the polycyclic aromatic hydrocarbon substrate.
Identification of a chromosomal determinant of enterotoxin A production in Staphylococcus aureus
Authors: Pattee P A , Glatz B A
Published: January 2020

Chromosomal mapping of the determinants for enterotoxin A and enterotoxin B production in three strains of Staphylococcus aureus was attempted by using conventional transformation procedures and a series of multiply marked derivatives of NCTC 8325 as recipients. A gene governing enterotixin A production (entA+) in strain S-6 was located on the chromosome between the pur-110 and ilv-129 markers, very close to a determinant of alpha-hemolysin production, hla+. The entA+ gene of strain FRI-196E was shown not to be located at the same position; its location could not be determined. The entB+ genes of strains S-6 and C243 were not located within the known linkage groups examined. Recombinants were screened for enterotoxin production by a new procedure that combined characteristics of immune serum plate and optimal sensitivity plate procedures. The strains and methods used in this study of enterotoxin determinants should prove useful in genetic studies to locate other chromosomal determinants of S. aureus whose phenotypes are difficult to score or select for.
Defined medium for Aquaspirillum serpens VHL effective in batch and continuous culture
Authors: Whitby G E , Murray R G
Published: January 2020

A defined medium for Aquaspirillum serpens VHL allows the replacement of the complex media now in use. It was developed by batch culture methods but supports growth in continuous culture. A basal salts medium supplemented with L-aspartic acid, L-alanine, and L-glutamic acid provided the best growth (turbidity), as long as ammonium chloride was omitted. Ammonium chloride caused either a lag or a reduction or a complete inhibition of the growth of A. serpens VHL on the above amino acids and other organic supplements depending on the combination used. Ammonium sulfate and ammonium hydroxide with L-glutamic acid allowed growth, but the lag period was increased in shake flask cultures. Vitamins, cysteine hydrochloride, and carbon dioxide had no effect on the growth rate. Viability (less than 50%) was inadequate to maintain continuous culture with L-glutamic acid as the sole source of carbon and nitrogen. Combinations of amino and carboxylic acids were then tested and, of these, L-glutamic acid (1 g/liter) and L-histidine (75 mg/liter) without ammonium chloride in the basal salts medium supported growth in batch and continuous culture. L-Glutamic acid was the limiting substrate for growth.
Two modified selenite media for the recovery of Yersinia enterocolitica from meats
Authors: Lee W H , Harris M E , McClain D , Smith R E , Johnston R W
Published: January 2020

Yersinia enterocolitica is one of the few human pathogens that grows at the proper food refrigeration temperatures of 0 to 5 degrees C. Although the isolation of environmental biotypes of Y. enterocolitica from many types of food and water has been reported in the literature, the recovery of the sensitive strains inoculated into foods has been slow and uncertain. Rapid recovery of several clinical strains inoculated into meats was accomplished by using two modified selenite broths without added nutrients. It was critical to restrict the sample size of the blended meat suspension at the 0.2-g/100 ml level, thereby restricting the growth of the total bacterial population in the selenite enrichment media. Otherwise, the slower growing Y. enterocolitica would be overwhelmed by the faster growing normal bacterial flora from the meat. Both the resistant serotype O:3 and the sensitive O:8 clinical isolates of Y. enterocolitica were recovered from the modified selenite enrichment media after 2 and 3 days of incubation at 22 degrees C.
Mechanism of Ozone Inactivation of Bacteriophage f2
Authors: Kim Chi K. , Gentile David M. , Sproul Otis J.
Published: January 2020

The inactivation kinetics of bacteriophage f2 were studied by using ozone under controlled laboratory conditions. The phage were rapidly inactivated during the first 5 s of the reaction by 5 and 7 logs at ozone concentrations of 0.09 and 0.8 mg/liter, respectively. During the next 10 min, the phage were further inactivated at a slower rate in both treatments. The [
3
H]uridine-labeled f2 phage and its ribonucleic acid (RNA) were examined to elucidate the mechanism of ozone inactivation, utilizing adsorption to host bacteria, sucrose density gradient analysis, and electron microscopy. The specific adsorption of the phage was reduced by ozonation in the same pattern as plaque-forming unit reduction. RNA was released from the phage particles during ozonation, although it had reduced infectivity for spheroplasts. Electron microscopic examination showed that the phage coat was broken by ozonation into many protein subunit pieces and that the specific adsorption of the phage to host pili was inversely related to the extent of phage breakage. The RNA enclosed in the phage coat was inactivated less by ozonation than were whole phage, but inactivated more than naked RNA. These findings suggest that ozone breaks the protein capsid into subunits, liberating RNA and disrupting adsorption to the host pili, and that the RNA may be secondarily sheared by a reduction with and/or without the coat protein molecules, which have been modified by ozonation.
Silicates as Nonspecific Adsorbents of Bacteriophage: a Model for Purification of Water from Viruses
Authors: Fass Refael , Straussman Yochevet , Shahar Abraham , Mizrahi Avshalom
Published: January 2020

Amorphous silicates having small particles with a large surface area were found to have high nonspecific adsorption capacity. Investigations with
Escherichia coli
T4 bacteriophage have shown adsorption capacity of up to 99.9% on different tested silicates. Optimal conditions for the adsorption of T4 bacteriophage on various commercially available silicates were determined. A continuous-flow adsorption of T4 bacteriophage on silicates appears to be a model system for the removal of viruses from potable water and sewage.
Adherent bacterial populations on the bovine rumen wall: distribution patterns of adherent bacteria
Authors: McCowan R P , Cheng K J , Costerton J W
Published: January 2020

Fourteen tissue sites from the bovine reticulo-rumen were examined by scanning electron microscopy to determine the distribution patterns of bacterial populations adhering to the epithelium. Although diet variations did not appear to influence the total number of tissue-adherent bacteria present in adult Herefords, diet affected their distribution. It appeared that the distribution of the bacterial populations may be directly affected by the physical state of the digesta. The digesta may be mechanically removing adherent bacteria from the tissue surface by abrasive action. The total adherent population consisted of subpopulations with separate distribution patterns, and macropopulations of morphologically similar bacteria were occasionally observed at specific sites on the epithelial surface. Ureolytic organisms on the epithelium followed a distribution pattern considerably different from the general bacterial distribution.
Direct Enzymatic Assay for Alcohol Oxidase, Alcohol Dehydrogenase, and Formaldehyde Dehydrogenase in Colonies of
Hansenula polymorpha
Authors: Eggeling L. , Sahm H.
Published: January 2020

A procedure is described for the qualitative direct identification of alcohol oxidase, alcohol dehydrogenase, and formaldehyde dehydrogenase in yeast colonies. The method has been applied successfully to isolate mutants of
Hansenula polymorpha
with altered glucose repression of alcohol oxidase.
Prevalence of enterotoxigenic Escherichia coli in some processed raw food from animal origin
Authors: Reis M H , Vasconcelos J C , Trabulsi L R
Published: January 2020

Eighteen of 1,200 colonies of Escherichia coli isolated from "keebe," hamburger, or sausage produced heat-labile enterotoxin. None of them produced heat-stable enterotoxin. The characteristics of 9 of the 18 strains are presented.
Increased production of extracellular enzymes by the synergistic effect of genes introduced into Bacillus subtilis by stepwise transformation
Authors: Yoneda Y
Published: January 2020

The amyR3, amyS, papS1, tmr, and papM118 mutations each stimulate alpha-amylase production two- to sevenfold above the level in a wild-type strain of Bacillus subtilis. A strain which presumably has all five of these mutations produced 250-fold more alpha-amylase.
Utilization of Ammonia Nitrogen by Intestinal Bacteria Isolated from Pigs
Authors: Takahashi M. , Benno Y. , Mitsuoka T.
Published: January 2020

In a medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, 17 of 24
Bacteroidaceae
strains, 3 of
Selenomonas
strains, 1 of 7 curved rods, 3 of 7
Spirochaetaceae
strains, 8 of 20
Eubacterium
strains, 8 of 13
Peptococcaceae
strains, 3 of 4
Clostridium
strains, 19 of 20
Enterobacteriaceae
strains, and 1 of 8
Streptococcus
strains utilized ammonia nitrogen preferentially to proteose peptone nitrogen. To determine the ability of intestinal microbes to synthesize amino acids from ammonia, ammonia utilization by
Bacteroides ruminicola
strain 9 was studied in defined media containing ammonia and other nitrogen sources. In another medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, ammonia was preferentially utilized even when the proteose peptone nitrogen content was eight times greater than that of ammonia nitrogen. In a medium containing ammonia, an amino acid, and cysteine, the lowest uptake of ammonia nitrogen was observed when the medium contained aspartic acid, glutamic acid, threonine, or alanine; but ammonia was utilized more effectively than any of the amino acids. Incorporation of
15
N from [
15
N]ammonia into bacterial amino acids was studied.
15
N was incorporated into every amino acid of
B. ruminicola
strain 9, and the highest uptake was observed in aspartic acid and alanine.
Fermentation Methods for Protein Enrichment of Cassava and Corn with
Candida tropicalis
Authors: Azoulay Edgard , Jouanneau Françoise , Bertrand Jean-Claude , Raphael Alain , Janssens Jacques , Lebeault Jean Michel
Published: January 2020

Candida tropicalis
grows on soluble starch, corn, and cassava powders without requiring that these substrates be previously hydrolyzed.
C. tropicalis
possesses the enzyme needed to hydrolyze starch, namely, an α-amylase. That property has been used to develop a fermentation process whereby
C. tropicalis
can be grown directly on corn or cassava powders so that the resultant mixture of biomass and residual corn or cassava contains about 20% protein, which represents a balanced diet for either animal fodder or human food. The fact that no extra enzymes are required to hydrolyze starch results in a particularly efficient way of improving the nutritional value of amylaceous products, through a single-step fermentation process.
Concentration of coliphages from large volumes of water and wastewater
Authors: Goyal S M , Zerda K S , Gerba C P
Published: January 2020

Membrane filter adsorption-elution technology has been extensively used for the concentration and detection of animal viruses from large volumes of water. This study describes the development of positively charged microporous filters (Zeta Plus) for the concentration of coliphages from large volumes of water and wastewater. Four different coliphages were studied: MS-2, phi X174, T2, and T4. Positively charged microporous filters were found to efficiently adsorb these coliphages from tap water, sewage, and lake water at neutral pH. Adsorbed viruses were eluted with a 1:1 mixture of 8% beef extract and 1 M sodium chloride at pH 9. Using this method, coliphages could be concentrated from 17-liter volumes of tap water with recoveries ranging from 34 to 100%. Coliphages occurring naturally in raw and secondarily treated sewage were recovered with average efficiencies of 56.5 and 55.0%, respectively. This method should be useful in isolation of rare phages, the ecology of phages in natural waters, and the evaluation of water quality.
Metabolism of Dibenzo-
p
-Dioxin and Chlorinated Dibenzo-
p
- Dioxins by a
Beijerinckia
Species
Authors: Klečka Gary M. , Gibson David T.
Published: January 2020

Whole cells of the parent strain of
Beijerinckia
, grown with succinate and biphenyl, oxidized dibenzo-
p
-dioxin and several chlorinated dioxins. The rate of oxidation of the chlorinated dibenzo-
p
-dioxins decreased with an increasing degree of chlorine substitution. A mutant strain (B8/36) of
Beijerinckia
oxidized dibenzo-
p
-dioxin to
cis
-1,2-dihydroxy-1,2-dihydrodibenzo-
p
-dioxin. The mutant organism also oxidized two monochlorinated dibenzo-
p
-dioxins to
cis
-dihydrodiols. No metabolites were detected from two dichlorinated dibenzo-
p
-dioxins. Growth of the parent strain of
Beijerinckia
on succinate was inhibited after 4 h when 0.05% dibenzo-
p
-dioxin was present in the culture medium. Resting cell suspensions of the parent organism, previously grown with succinate and biphenyl, oxidized dibenzo-
p
-dioxin to a compound identified as 1,2-dihydroxydibenzo-
p
-dioxin. Further degradation of this metabolite was not detected, as the compound was found to be a potent mixed-type inhibitor of two ring-fission oxygenases present in this organism.
Biological Process for Converting Naphthalene to
cis
-1,2-Dihydroxy-1,2-Dihydronaphthalene
Authors: Cox D. P. , Williams A. L.
Published: January 2020

A biological process for converting naphthalene to
cis
-1,2-dihydroxy-1,2-dihydronaphthalene (DHD) catalyzed by
Pseudomonas putida
strain 119 was optimized in flask experiments. These studies revealed the following: (i)
P. putida
119 can propagate efficiently and produce DHD when supplied one of several carbon sources and naphthalene; (ii) maximum DHD production by
P. putida
119 occurs in logarithmic-growth-phase cells and decreases at various rates in the stationary growth phase, depending upon the carbon source used; (iii) several analogs of salicylic acid can be used as effective inducers of naphthalene metabolism in
P. putida
cells growing on glucose; and (iv) the addition of chemical surfactants to naphthalene-cell (
P. putida
119) mixtures stimulates DHD production.
Destruction by Anaerobic Mesophilic and Thermophilic Digestion of Viruses and Indicator Bacteria Indigenous to Domestic Sludges
Authors: Berg Gerald , Berman Donald
Published: January 2020

In raw sludges and in mesophilically and thermophilically digested anaerobic sludges, large variations in numbers of viruses occurred over narrow ranges of numbers of fecal coliforms, total coliforms, and fecal streptococci, demonstrating that the bacteria were poor quantitative reflectors of the numbers of the viruses detected. Mesophilic and thermophilic digestion of anaerobic sludges destroyed all three indicator bacteria more rapidly than such digestion destroyed the viruses. The relative rates for the destruction of viruses, fecal coliforms, and fecal streptococci in the digested sludges were consistent over the 17-month study. Fecal coliforms were 7 to 8 times more sensitive than the viruses to mesophilic digestion and 9 to 10 times more sensitive to thermophilic digestion. Total coliforms were even more sensitive. The rates at which fecal streptococci were destroyed by mesophilic and thermophilic digestion of anaerobic sludges approached those at which the viruses were destroyed by those processes; this suggested that the rates at which fecal streptococci in sludges are destroyed by those processes may serve as useful indicators for the rates at which viruses in sludges are destroyed by those processes.
Adherence of Vibrio parahaemolyticus to human epithelial cell lines
Authors: Gingras S P , Howard L V
Published: January 2020

Light microscopy and a radioassay detected no significant difference in adherence of Kanagawa-positive and Kanagawa-negative strains of Vibrio parahaemolyticus to human epithelial cell lines.
Applications of fluorophore-containing microbial growth media
Authors: Ramsey W S , Nowlan E D , Simpson L B , Messing R A , Takeguchi M M
Published: January 2020

Media containing the fluorogenic compound 8-anilino-1-naphthalene sulfonic acid may be used to discriminate between gram-positive and gram-negative bacteria and to differentiate between various species of bacteria. Fluorescent light emitted from colonies of gram-negative bacteria on 8-anilino-1-naphthalene sulfonic acid-containing agar was visually more intense than that on gram-positive bacteria. The emitted light from the gram-negative bacteria differed in wave-lengths from that of light emitted by colonies of gram-positive bacteria. The fluorescent intensity of colonies on complete 8-anilino-1-napthalene sulfonic acid agar supplemented with 1% of single substrates varied depending on the bacterial species, thus allowing the development of profiles used to identify 12 different species.
Use of a Cellulase-Derepressed Mutant of
Cellulomonas
in the Production of a Single-Cell Protein Product from Cellulose
Authors: Hitchner E. V. , Leatherwood J. M.
Published: January 2020

A cellulase-derepressed mutant of a
Cellulomonas
species was used to produce single-cell protein from crystalline cellulose. In preliminary tests, maximum yield of single-cell protein was obtained at 30°C (pH 7.0) with urea as the nitrogen source. A continuous-flow foam flotation procedure was developed for rapid and efficient separation of bacteria from the culture liquid and cellulose residue. A pH of 4.5 was optimum for foam flotation of this organism. In preliminary trials, recovery was 85% of the cells with the flotation procedure.
Cellulomonas
was 68% true protein and had an essential amino acid profile featuring a high lysine content (6.5% of protein). The
Cellulomonas
product was evaluated nutritionally with weanling rats. The net protein utilization value for the protein supplemented with methionine was 50.4% Weight gain of rats on the
Cellulomonas
diet was similar to that of rats fed a casein diet.
Isolation and Analysis of Molds from Soy Sauce Koji in Thailand
Authors: Bhumiratana A. , Flegel T. W. , Glinsukon T. , Somporan W.
Published: January 2020

Five different isolates of
Aspergillus
and one of
Mucor
were compared with a Japanese commercial strain of
Aspergillus oryzae
for proteolytic activity on wheat bran substrate. One isolate of
Aspergillus
with superior protease production, identified as
Aspergillus flavus
var.
columnaris
, showed no detectable aflatoxin production on glutinous rice or soybean substrate. Preliminary tests using this fungus as a koji mold in a traditionally operated factory resulted in a soy sauce superior in quality to that usually produced.
Methanogenic Decomposition of Ferulic Acid, a Model Lignin Derivative
Authors: Healy J. B. , Young L. Y. , Reinhard M.
Published: January 2020

Ferulic acid, a model lignin derivative, was observed to be biodegradable to methane and carbon dioxide under strict anaerobic conditions. This conversion appears to be carried out by a consortium of bacteria similar to that previously described for the methanogenic degradation of benzoic acid. A temporary buildup of acetate in these cultures indicates that it is a likely intermediate and precursor for methane formation. An analog of coenzyme M, 2-bromoethanesulfonic acid (BESA), inhibited gas production and enhanced the buildup of propionate, butyrate, isobutyrate, and isovalerate. Phenylacetate, cinnamate, 3-phenylpropionate, benzoate, cyclohexane carboxylate, adipate, and pimelate were also detected in BESA-inhibited cultures. A pathway is proposed which includes these various acids as possible intermediates in the methanogenic degradation of ferulic acid. This model overlaps previously described benzoic acid degradation pathways, suggesting that this type of anaerobic degradation may be common for aromatic compounds.
Changes in macromolecular composition and morphology of Bacteroides fragilis cultured in a complex medium
Authors: Frantz J C , McCallum R E
Published: January 2020

Changes in cell macromolecular composition during different phases of growth correlated with alterations in morphology of the obligately anaerobic bacterium, Bacteroides fragilis, grown in a complex medium.
Growth of Legionella pneumophila in association with blue-green algae (cyanobacteria)
Authors: Tison D L , Pope D H , Cherry W B , Fliermans C B
Published: January 2020

Legionella pneumophila (Legionnaires disease bacterium) of serogroup 1 was isolated from an algal-bacterial mat community growing at 45 degrees C in a man-made thermal effluent. This isolate was grown in mineral salts medium at 45 degrees C in association with the blue-green alga (cyanobacterium) Fischerella sp. over a pH range of 6.9 to 7.6. L. pneumophila was apparently using algal extracellular products as its carbon and energy sources. These observations indicate that the temperature, pH, and nutritional requirements of L. pneumophila are not as stringent as those previously observed when cultured on complex media. This association between L. pneumophila and certain blue-green algae suggests an explanation for the apparent widespread distribution of the bacterium in nature.
Use of Two-Dimensional Polyacrylamide Electrophoresis to Demonstrate that Putative
Rhizobium
Cross-Inoculation Mutants Actually Are Contaminants
Authors: Leps Walter T. , Roberts G. P. , Brill Winston J.
Published: January 2020

Two-dimensional polyacrylamide electrophoresis was used to determine that mutants of
Rhizobium trifolii
DT6, claimed to be capable of effectively nodulating soybeans, were actually
Rhizobium japonicum
110 contaminants isolated from the parent DT6 culture.
Desulfuration of Dialkyl Thiophosphoric Acids by a Pseudomonad
Authors: Cook Alasdair M. , Daughton Christian G. , Alexander Martin
Published: January 2020

A strain of
Pseudomonas acidovorans
used the organophosphorus pesticide breakdown products, ionic
O,O
-diethyl phosphorothioate and ionic
O,O
-diethyl phosphorodithioate, as sulfur sources. The growth yields from the thiophosphates and sulfate were 3.6 to 4.1 kg of protein per mol of sulfur. Elemental sulfur and sulfide also served as sulfur sources but gave lower growth yields.
Simple method for the concentration of influenza virus from allantoic fluid on microporous filters
Authors: Goyal S M , Hanssen H , Gerba C P
Published: January 2020

Membrane filter adsorption-elution is an efficient method for concentration and partial purification of several types of viruses from various aqueous solutions. For efficient virus adsorption to negatively charged filters, the sample is adjusted to pH 3.5 and trivalent salts are added before filtration. Since influenza virus is sensitive to extremes in pH, it cannot be concentrated by ordinary filters. Zeta Plus filters, which have a net positive charge of up to 5 or 6, were evaluated for the concentration of influenza virus from infectious allantoic fluids. Influenza virus efficiently adsorbed to Zeta Plus filters at pH 6, and addition of salts was not necessary. Adsorbed virus was eluted in a small volume of 2% bovine serum albumin plus 1 M NaCl at pH 10. By this procedure, viruses in 100 ml of allantoic fluid were concentrated to a final volume of 8 ml, with an average recovery efficiency of 71.0%.
Reversal of radiation-dependent heat sensitization of Clostridium perfringens spores
Authors: Gomez R F , Gombas D E , Herrero A
Published: January 2020

The effect of solute concentration on the sensitization of Clostridium perfringens spores to heat by ionizing radiation was investigated. As we have shown previously, spores of C. perfringens treated with gamma radiation are now sensitive to subsequent heat treatments than are spores that receive no radiation treatment. When gamma-irradiated spores were heated in the presence of increasing concentrations of glycerol or sucrose, the heat sensitivity induced by irradiation was progressively decreased. The magnitude of the increase in heat resistance induced by extracellular solutes was greater in gamma-irradiated spores than in nonirradiated spores. Based on these observations, it is proposed that the induction of heat sensitivity in spores by radiation is related to the loss of osmoregulatory or dehydrating mechanisms in irradiated spores.
Characterization of staphylococci isolated from mastitic cows in Spain
Authors: Garcia M L , Moreno B , Bergdoll M S
Published: January 2020

A total of 57 gram-positive, catalase-positive cocci, considered etiological agents of clinical and subclinical bovine mastitis, were tested for glucose and mannitol fermentation, coagulase and thermonuclease production, sensitivity to lysostaphin, gelatin hydrolysis, lysozyme, phosphatase and egg yolk factor production, hemolytic properties, antibiotic sensitivity, susceptibility to human and bovine phages, and enterotoxin production. All 57 strains were identified as staphylococci. A good correlation was found between 3+ and 4+ coagulase reactions, thermonuclease production, and high sensitivity to lysostaphin. Neither mannitol fermentation nor production of other enzymes appeared to be a specific property of bovine Staphylococcus aureus strains. beta- and delta-hemolysins were more frequently found than alpha-hemolysin. Nearly 40% of the strains were penicillin resistant. Strains were lysed by phage 42E from the human phage set more frequently than by phage 42D, whereas with the bovine set, strains were more sensitive to specific bovine phages. Three strains produced enterotoxin C, and one strain produced enterotoxin D.
Relationships Between Environmental Factors, Bacterial Indicators, and the Occurrence of Enteric Viruses in Estuarine Sediments
Authors: LaBelle Raymond L. , Gerba Charles P. , Goyal Sagar M. , Melnick Joseph L. , Cech Irina , Bogdan Gregory F.
Published: January 2020

Current standards for evaluation of the public health safety of recreational and shellfish-harvesting waters are based upon bacteriological analysis, but do not include an evaluation of the number of viruses. The objective of this study was to determine the occurrence of enteric viruses in estuarine sediments and to find a relationship, if any, between the presence of viruses in seawater or sediment or both and various biological and physicochemical characteristics of the environment. Viruses were found in greater numbers in sediment than in overlying seawater on a volume basis. Several types of enteroviruses were isolated: coxsackievirus types A16, B1, and B5, echovirus type 1, and poliovirus type 2. On several occasions, viruses were isolated from sediments when overlying seawaters met bacteriological water quality standards for recreational use. Statistical analysis of the relationship between viruses in seawater or in sediment and other variables measured yielded only one significant association: the number of viruses in sediment was found to be positively correlated with the number of fecal coliforms in sediment. No other physical, chemical, or biological characteristic of seawater or sediment that was measured showed statistically significant association with viral numbers. No correlation was found between bacterial indicators and virus in the overlying waters. The data indicated that evaluation of the presence of bacteria and viruses in sediment may provide additional insight into long-term water quality conditions and that indicator bacteria in water are not reflective of the concentration of enteric viruses in marine waters.
Cytoplasmic reserve polysaccharide of Selenomonas ruminantium
Authors: Wallace R J
Published: January 2020

Selenomonas ruminantium accumulated large quantities of intracellular polysaccharide when grown in simple defined medium in a chemostat, particularly at low dilution rate under NH3 limitation when the carbohydrate content of the cells was greater than 40% of the dry weight. This polysaccharide was used as a source of energy under conditions of energy starvation. Abundant, densely staining cytoplasmic granules were observed by electron microscopy in sections stained by the periodic acid-thiocarbohydrazide-osmium technique. The polysaccharide was extracted in 30% KOH followed by precipitation with 60% ethanol and was found to be a glucose homopolymer. Sepharose 4B gel filtration and iodine-complex spectroscopy showed that the polysaccharide was of the glycogen type with a molecular weight of 5 X 10(5) to greater than 20 X 10(5) and an average chain length of 12 glucose residues.
Influence of Seasonal Temperature on the Temperature Optima of Bacteria in Sediments of Lake George, New York
Authors: Tison David L. , Pope Daniel H. , Boylen Charles W.
Published: January 2020

Temperature optima for the heterotrophic utilization of glucose and an amino acid mixture were determined throughout the year in sediments from Lake George, N.Y. The temperature optimum decreased with decreasing in situ temperature in the fall and winter, suggesting that selection for or adaptation by a psychrotrophic bacterial population occurred. Replicate plating of bacterial isolates from 3 and 20°C indicated that a psychrotrophic bacterial population was present in the sediments throughout the year. These results indicate that decomposition and nutrient cycling processes in the sediments within the littoral zone of Lake George were probably not completely inhibited by winter temperatures, although process rates were decreased.
Beta-Amylase Production by
Bacillus polymyxa
on a Corn Steep-Starch-Salts Medium
Authors: Hensley Dwight E. , Smiley Karl L. , Boundy Joyce A. , Lagoda Adolph A.
Published: January 2020

Bacteria were found that are capable of producing good yields of β-amylase in unrefined media. The culture filtrates are free of α-amylase and isoamylase.
Resistance and recovery studies on ultraviolet-irradiated spores of Bacillus pumilus
Authors: Abshire R L , Bain B , Williams T
Published: January 2020

A spore suspension model and a procedure for recovering ultraviolet (UV)-irradiated spores of Bacillus pumilus were investigated. A most-probable-number tube dilution method using double-strength Trypticase soy broth was found to be superior to the agar plate method for recovering optimal numbers of spores irradiated with sublethal doses of UV energy. Aqueous suspensions of B. pumilus survived UV doses up to 108,000 ergs/mm2 as determined by a most-probable-number recovery and estimation procedure. Resistance and stability data were consistent and reproducible, indicating the dependability of this method for recovering UV-damaged spores. The procedures used to collect information concerning resistance characteristics for two strains of B. pumilus are discussed.
Microbial Oxidation of Gaseous Hydrocarbons: Production of Methylketones from Corresponding
n
-Alkanes by Methane-Utilizing Bacteria
Authors: Patel Ramesh N. , Hou C. T. , Laskin A. I. , Felix A. , Derelanko P.
Published: January 2020

Cell suspensions of methane-utilizing bacteria grown on methane oxidized
n
-alkanes (propane, butane, pentane, hexane) to their corresponding methylketones (acetone, 2-butanone, 2-pentanone, 2-hexanone). The product methylketones accumulated extracellularly. The rate of production of methylketones varied with the organism used for oxidation; however, the average rate of acetone, 2-butanone, 2-pentanone, and 2-hexanone production was 1.2, 1.0, 0.15, and 0.025 μmol/h per 5.0 mg of protein in cell suspensions. Primary alcohols and aldehydes were also detected in low amounts as products of
n
-alkane (propane and butane) oxidation, but were rapidly metabolized further by cell suspensions. The optimal conditions for in vivo methylketone formation from
n
-alkanes were compared in
Methylococcus capsulatus
(Texas strain),
Methylosinus
sp. (CRL-15), and
Methylobacterium
sp. (CRL-26). The rate of acetone and 2-butanone production was linear for the first 60 min of incubation and directly increased with cell concentration up to 10 mg of protein per ml for all three cultures tested. The optimal temperatures for the production of acetone and 2-butanone were 35°C for
Methylosinus trichosporium
sp. (CRL-15) and
Methylobacterium
sp. (CRL-26) and 40°C for
Methylcoccus capsulatus
(Texas). Metal-chelating agents inhibited the production of methylketones, suggesting the involvement of a metal-containing enzymatic system in the oxidation of
n
-alkanes to the corresponding methylketones. The soluble crude extracts derived from methane-utilizing bacteria contained an oxidized nicotinamide adenine dinucleotide-dependent dehydrogenase which catalyzed the oxidation of secondary alcohols.
Impact of detergent systems on bacterial survival on laundered fabrics
Authors: Jaska J M , Fredell D L
Published: January 2020

The survival of Staphylococcus aureus was determined from inoculated swatches laundered in either a phosphate or a phosphate-substitute detergent. In a Plackett-Burman design study, the independent variables of detergent type, concentration, and variation, wash water temperature, soil load, cycle time, and water hardness were assigned high and low values. Wash water temperatures of 27, 38, 49, and 60 degrees C were employed. Viable bacteria were recovered from macerated swatches. Statistical analysis disclosed that there was no practical difference in the ability of phosphate or phosphate-substitute detergents to reduce the level of S. aureus on the laundered swatches in this controlled design. Analysis did reveal that water temperature was the most significant independent variables. The remaining variables did not appear to have any practical significance upon bacterial reduction. This bacteriological study did not evaluate other essential detergent properties.
Occurrence of Cytophagas in Sewage Plants
Authors: Güde Hans
Published: January 2020

With the application of plate count methods and of the KOH-flexirubin test, bacteria belonging to the
Cytophaga
group were proved to occur regularly in samples from biological sewage treatment facilities. Generally, the percentage of
Cytophaga
colonies of the total heterotrophic colonies was lowest in the inflow sewage water as compared with the values found in activated sludge, trickling filter, and effluent samples. During an observation period of 16 months, the highest percentages of cytophagas were found in winter samples from activated sludge and trickling filters. Furthermore, cytophagas were shown to have high percentages of the bacteria lytic to polymeric substrates such as cellulose, chitin, dextran, pectin, xylan, and gelatin. Thus, it is suggested that cytophagas may contribute to sewage purification, especially at cold temperatures and by polymer breakdown.
Cytophaga
strains isolated were shown to have gliding motility, flexirubin pigmentation, and a low guanine plus cytosine base ratio in common. The strains were roughly subdivided into a spreading, a nonspreading, and a cellulolytic group.
Microbial prevalence in domestic humidifiers
Authors: Burge H A , Solomon W R , Boise J R
Published: January 2020

The prevalence of viable thermophilic bacteria and actinomycetes and mesophilic fungi was examined in 145 samples from 110 domestic humidifiers. A total of 72 and 43% of furnace and console humidifier samples, respectively, contained viable thermophilic bacteria, whereas 60 and 72% of these samples produced mesophilic fungal growth. Thermophilic actinomycetes were recovered from seven humidifier samples. Efforts to detect thermophilic actinomycete antigens in 15 humidifier fluid samples were not successful. Antifoulants added to humidifier fluid reservoirs had no apparent effect on microbial frequency. Airborne microbial recoveries did not reflect patterns of humidifier contamination with respect to either kinds or numbers of microorganisms in 20 homes in which volumetric air samples were obtained during humidifier operation.
Microbial Production of Pectin from Citrus Peel
Authors: Sakai Takuo , Okushima Minoru
Published: January 2020

A new method for the production of pectin from citrus peel was developed. For this purpose, a microorganism which produces a protopectin-solubilizing enzyme was isolated and identified as a variety of
Trichosporon penicillatum
. The most suitable conditions for the pectin production were determined as follows. Citrus (
Citrus unshiu
) peel was suspended in water (1:2, wt/vol), the organism was added, and fermentation proceeded over 15 to 20 h at 30°C. During the fermentation, the pectin in the peel was extracted almost completely without macerating the peel. By this method, 20 to 25 g of pectin was obtained per kg of peel. The pectin obtained was special in that it contained neutral sugar at high levels, which was determined to have a molecular weight suitable for practical applications.
Dispersal of
Aspergillus fumigatus
from Sewage Sludge Compost Piles Subjected to Mechanical Agitation in Open Air
Authors: Millner Patricia D. , Bassett David A. , Marsh Paul B.
Published: January 2020

Aerosolization of the thermophilous fungal opportunist
Aspergillus fumigatus
from mechanically agitated compost piles was examined at a pilot-scale sewage sludge composting facility and two other selected test sites. Aerosols of
A. fumigatus
downwind from stationary compost piles were insignificant in comparison with those downwind from agitated piles. These aerosols were generated by a front-end loader moving and dropping compost. Aerial concentrations of the fungus at distances downwind from the point of emission were used to determine an emission rate for
A. fumigatus
associated with the moving operations. The maximum emission rate, 4.6 � 10
6
A. fumigatus
particles per s, was used to calculate predicted concentrations in an unobstructed plume with restrictive, neutral, and dispersive atmospheric mixing conditions up to 1 km downwind from the emission source.
Death of
Micrococcus luteus
in Soil
Authors: Casida L. E.
Published: January 2020

Micrococcus luteus
cells died relatively quickly when they were added to natural soil. The results were similar for soil in nature and as soil samples in the laboratory. The cells died more quickly when nutrients were added to the soil. Those cells that survived soil residence exhibited a temporary lengthening of the time required for colonial growth and pigment formation on laboratory media. They had not gained increased survival capability, however. This was evident when they were retested in soil. Good survival of the
M. luteus
cells was noted when the soil was incubated at lowered temperatures. Some protection to the cells was provided by slow drying of the soil during incubation or by addition of NaCl. Microscopic examination of the soil revealed that the
M. luteus
cells were being physically destroyed and that two different bacteria were growing in the areas where the cells had lysed. It was suggested that bacterial predators in the soil might be associated with the death of the
M. luteus
cells.
Fluorescent Staining Technique for Nucleoid Regions of
Streptosporangium albidum
and
Streptosporangium brasiliense
Authors: Speth J. L. , Nash C. H.
Published: January 2020

Fluorescent staining procedures were developed for elucidating the nucleoid region in
Streptosporangium albidum
and
Streptosporangium brasiliense
. In these procedures, plugs of nutrient agar were inoculated with the microorganims and then covered with a sterile glass slide. The growing cells adhered to the surface of the slide and remained attached throughout the staining procedures. Two separate staining methods were utilized, one with bisbenzimid H33258 and the other with auramine O. Fluorescent microscopy revealed intensely stained nucleoid regions within mycelia, spores, and sporangia.
Effect of moderately acidic pH on heat resistance of Clostridium sporogenes spores in phosphate buffer and in buffered pea puree
Authors: Cameron M S , Leonard S J , Barrett E L
Published: January 2020

The effect of pH in the range 5.0 to 7.0 on the thermal destruction of spores of Clostridium sporogenes putrefactive anaerobe 3679 was examined by three methods: a capillary tube method in which spores were suspended in phosphate buffers, a thermoresistometer method in which spores were suspended in buffered pea puree adjusted to the same set of pH values, and a thermal death time can method in which spores were again suspended in buffered pea puree. The results indicated that increasing acidity is, in general, accompanied by decreasing heat resistance, although the pH effect was more pronounced at the higher than at the lower processing temperatures. Certain pH values appear to be critical, as they produced, in all three sets of experiments, effects which would not be predicted by the overall relationship between acidity and spore heat resistance. Differences between heat resistance in phosphate buffer as compared with that in pea puree adjusted to the same pH were also noted. D-values in buffer were found to be lower than those in pea puree, except at the highest temperatures coupled with the lowest pH values. The differences between buffer D-value and pea puree D-value were found to increase with increasing pH and with decreasing temperature. On the other hand, at all pH values examined, z-values determined in buffer were somewhat higher than those determined in pea puree adjusted to the same pH.
Acetate as Sole Carbon and Energy Source for Growth of
Methanosarcina
Strain 227
Authors: Smith Michael R. , Mah Robert A.
Published: January 2020

Methanosarcina
strain 227 grew rapidly and produced methane on a mineral medium containing acetate as the sole added organic substrate. Cell yields but not doubling times were affected by the presence or absence of yeast extract. Greater cell yields occurred in yeast extract medium than in mineral medium. Radioactive labeling studies showed that acetate was decarboxylated in mineral medium, as was shown previously in complex medium. The specific radioactivity of methane produced per specific acitvity of acetate added was not significantly different in yeast extract medium compared with mineral medium. Unequivocal evidence indicates that the cleavage of acetate to methane and carbon dioxide provided the energy for growth in the presence or absence of other organic compounds; these latter compounds do not serve as energy sources, electron donors, or significant sources of methane during this aceticlastic reaction.
Bacterioplankton Secondary Production Estimates for Coastal Waters of British Columbia, Antarctica, and California
Authors: Fuhrman Jed A. , Azam Farooq
Published: January 2020

The principal objective of this study was to quantify the rate of heterotrophic bacterioplankton production. Production was estimated by two approaches: (i) measurement of increasing bacterial abundance with time in filtered (3-μm pore size) seawater and (ii) estimation of bacterial deoxyribonucleic acid synthesis by tritiated thymidine incorporation in unfractionated seawater. The two approaches yielded comparable results when used at the Controlled Ecosystem Population Experiment (Saanich Inlet, British Columbia, Canada), at McMurdo Sound (Antarctica), and off Scripps Pier (La Jolla, Calif.). Estimated bacterioplankton production was lower in Antarctic samples (ranging from ∼0 to 2.9 μg of C liter
−1
day
−1
) than in those from the other two sites (ranging from 0.7 to 71 μg of C liter
−1
day
−1
). In all three regions studied, it appeared that a significant fraction of the total primary production was utilized by the bacterioplankton and that substantial growth could occur in the absence of large particles. These results support the conclusion that bacterioplankton are a quantitatively important component of coastal marine food webs.