bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of sulfur by spirillum 5175 and syntrophism with Chlorobium
Authors: Wolfe R S , Penning N
Published: January 2020

A small spirillum, designated 5175, was isolated from an anaerobic enrichment culture for Desulfuromonas in which the major medium constituents were acetate and elemental sulfur. The organisms grew only under anaerobic or microaerophilic conditions. Elemental sulfur was formed anaerobically in a malate-sulfide medium, and cell densities of 10(8) cells/ml were obtained. Hydrogen and formate were actively oxidized as substrates for growth under anaerobic conditions; S0, S032-, or S2O32-, but not SO42-, served as electron acceptors and were stoichiometrically reduced to sulfide. Malate or fumarate likewise served as electron acceptors and were reduced to succinate. Nutritional requirements were simple, no vitamins or amino acids being required. For growth in inorganic media when carbon dioxide was the only carbon source, the addition of acetate was required as a source of cell carbon. The organism is gram negative. Cells had a diameter of 0.5 mum and a wavelength of 5.0 mum. Cell suspensions exhibited an absorption spectrum indicative of a cytochrome with peaks in the reduced form at 552, 523, and 416 nm. Well growing syntrophic cultures with Chlorobium were established with formate as the substrate.
Leakage of cellular material from Thiobacillus ferrooxidans in the presence of organic acids
Authors: Tuttle J H , Dugan P R , Apel W A
Published: January 2020

Thiobacillus ferroodixans cells released varying amounts of iron, phosphate, sugar, ribonucleic acid, deoxyribonucleic acid, and substances that absorbed light at both 260 and 280 nm, when exposed to 10(-2) to 10(-1) M concentrations of these organic acids: propionic, butyric, valeric, hexanoic, and oxalacetic. These acids also retarded iron oxidation by the cells. Electron microscope observation of cells after exposure to the organic acids showed varying degrees of cell envelope disruption, suggesting that the mode of inhibition of autotrophic iron oxidation in the cell involves interference with the function of the cell envelope, possibly the cell membrane.
Stable gas-liquid chromatography column for fatty acid analysis
Authors: Hansen L B , Kuhnley L , Kenner C T
Published: January 2020

A mixed gas-liquid chromatography column of FFAP and Apolar-7CP has excelelnt thermal stability and shows excellent characteristics for the separation of the methylesters of fatty acids from Salmonella enteritidis call wall lipids.
Correction for the inherent error in optical density readings
Authors: Lawrence J V , Maier S
Published: January 2020

Except at very low levels, uncorrected photometric determination of bacterial cell densities showed a decreasing proportionally to actual cell density or dry weight. A standard curve was prepared to convert photometric readings to truly proportional optical density values. With one dry weight determination, optical density values may be converted to absolute dry weight values.
Use of Adenosine 5′-Triphosphate as an Indicator of the Microbiota Biomass in Rumen Contents
Authors: Forsberg C. W. , Lam K.
Published: January 2020

A number of techniques were tested for their efficiency in extracting adenosine 5′-triphosphate (ATP) from strained rumen fluid (SRF). Extraction with 0.6 N H
2
SO
4
, using a modification of the procedure described by Lee et al. (1971), was the most efficient and was better suited for extracting particulate samples. Neutralized extracts could not be stored frozen before assaying for ATP because large losses were incurred. The inclusion of internal standards was necessary to correct for incomplete recovery of ATP. The ATP concentration in rumen contents from a cow receiving a ration of dried roughage (mainly alfalfa hay) ranged from 31 to 56 μg of ATP per g of contents. Approximately 75% of the ATP was associated with the particulate material. The ATP was primarily of microbial origin, since only traces of ATP were present in the feed and none was found in “cell-free” rumen fluid. Fractionation of the bacterial and protozoal populations in SRF resulted in the isolation of an enriched protozoal fraction with a 10-fold higher ATP concentration than that of the separated rumen bacteria. The ATP pool sizes of nine functionally important rumen bacteria during the exponential phase of growth ranged from 1.1 to 17.6 μg of ATP per mg of dry weight. This information indicates that using ATP as a measure of microbial biomass in rumen contents must be done with caution because of possible variations in the efficiency of extraction of ATP from rumen contents and differences in the concentration of ATP in rumen microbes.
Control of Sexual Reproduction in
Gibberella zeae (Fusarium roseum
“Graminearum”)
Authors: Wolf J. C. , Mirocha C. J.
Published: January 2020

Sexual reproduction in
Gibberella zeae (Fusarium roseum)
is regulated by the fungal sex hormone zearalenone, which is known to be synthesized only by species of
Fusarium.
The presence of cyclic adenosine 3′,5′-monophosphate (cAMP) in mycelium of this fungus has been confirmed by analyses with thin-layer and gas-liquid chromatography, fluorescent properties, ultraviolet absorption, competitive protein-binding tests, and degradation by cyclic phosphodies-terase. cAMP but not cyclic guanosine monophosphate increased both the number of perithecia formed and the incorporation of [1-
14
C]acetate into zearalenone. It is proposed that cAMP stimulates the synthesis of zearalenone which then exerts its effect directly or indirectly on formation of perithecia.
The Environment and the Microbial Ecology of Human Skin
Authors: McBride Mollie E. , Duncan W. Christopher , Knox J. M.
Published: January 2020

Microbial flora of the skin of three human population groups representing different natural environments was examined quantitatively and qualitatively to determine whether environmental differences in temperature and humidity can influence the microbial flora of normal skin. Five anatomical skin sites - hands, back, axillae, groin, and feet - were sampled from 10 subjects working in a high-humidity, high-temperature environment, 10 subjects from a low-temperature, high-humidity environment, and 10 subjects working in a moderate-temperature and low-humidity environment. Bacterial populations were significantly larger from the back, axillae, and feet in individuals from the high-temperature and high-humidity environment as compared to the moderate-temperature, low-humidity environment. High humidity and low temperature had no significant effect on total populations, but this group showed a higher frequency of isolation of fungi, and gram-negative bacteria from the back and feet. Although there was an indication that increase in the environmental humidity could result in an increased frequency of isolation of gram-negative bacteria, there was no evidence that an increase in either temperature or humidity altered the relative proportions of gram-negative bacteria in the predominantly gram-positive microbial flora found on normal skin. It was concluded that, although climatic changes may cause fluctation in microbial populations from certain sites, they are not a major influence on the ecology of the microbial flora of normal skin in the natural environment. The variables introduced by studying individuals in their natural environment and the influence of these on the results are discussed.
Survival of a Psychrophilic Marine Vibrio Under Long-Term Nutrient Starvation
Authors: Novitsky James A. , Morita Richard Y.
Published: January 2020

Ant-300, a psychrophilic marine vibrio isolated from the surface water of the Antarctic convergence, was starved for periods of more than 1 year. During the first week of starvation, cell numbers increased from 100 to 800% of the initial number of cells. Fifty percent of the starved cells remained viable for 6 to 7 weeks while a portion of the population remained viable for more than 1 year. During the first 2 days of starvation, the endogenous respiration of the cells decreased over 80%. After 7 days, respiration had been reduced to 0.0071% total carbon respired per hour and remained constant thereafter. After 6 weeks of starvation, 46% of the cellular deoxyribonucleic acid had been degraded. Observation of the cellular deoxyribonucleic acid with Feulgen staining before starvation showed the average number of nuclear bodies per cell varied from 1.44 to 4.02 depending on the age of the culture. A linear relationship was found between the number of nuclear bodies per cell and the increase in cell numbers upon starvation. Our data suggest that Ant-300 is capable of surviving long periods of time with little or no nutrients and is therefore well adapted for the sparse nutrient conditions of the colder portions of the open ocean.
Retrieval of Concentrated and Undecompressed Microbial Populations from the Deep Sea
Authors: Jannasch H. W. , Wirsen C. O.
Published: January 2020

A device for sampling at depths of up to 6,000 m is described in which 3 liters of seawater is concentrated over a Nucleopore filter to about 13 ml and retrieved under in situ pressure and temperature. Subsamples can be withdrawn into transfer units that are equipped with individual gas accumulators for preventing loss of pressure during prolonged periods of storage. Transfer of samples or sample portions into sterile medium contained in pre-pressurized incubation vessels and continued subsampling therefrom permit time course experiments for the study of natural populations of deep-sea microorganisms in the absence of decompression. A test experiment with a water sample from a depth of 2,600 m supplemented with radioactively labeled Casamino Acids showed reduced rates of substrate incorporation and respiration as compared with data from a decompressed control. The barotolerance observed in this study was characterized by reduced, rather than equal, activities recorded at elevated pressures as compared with 1-atm controls.
Extradiol Cleavage of 3-Methylcatechol by Catechol 1,2-Dioxygenase from Various Microorganisms
Authors: Hou C. T. , Patel R. , Lillard M. O.
Published: January 2020

The isofunctional enzymes of catechol 1,2-dioxygenase from species of
Acinetobacter, Pseudomonas, Nocardia, Alcaligenes
, and
Corynebacterium
oxidize 3-methylcatechol according to both the intradiol and extradiol cleavage patterns. However, the enzyme preparations from
Brevibacterium
and
Arthrobacter
have only the intradiol cleavage activity. Comparison of substrate specificity among these isofunctional dioxygenases shows striking differences in the oxidation of 3-methylcatechol, 4-methylcatechol and pyrogallol.
Comparative Study of Two Methods for Detection of
Clostridium perfringens
in Ground Beef
Authors: Emswiler B. S. , Pierson C. J. , Kotula A. W.
Published: January 2020

The tryptose-sulfite-cycloserine agar pour plate method was superior to selective enrichment in liquid sulfite medium for isolation of small numbers of
Clostridium perfringens
from frozen ground beef.
Technique for Isolating Phage for
Azotobacter vinelandii
Authors: Bishop Paul E. , Supiano Mark A. , Brill Winston J.
Published: January 2020

An enrichment technique was developed whereby azotophage could readily be isolated after inoculation of soil sites with
Azotobacter vinelandii.
Inactivation by Ionizing Radiation of
Salmonella enteritidis
Serotype montevideo Grown in Composed Sewage Sludge
Authors: Brandon J. R. , Burge W. D. , Enkiri N. K.
Published: January 2020

S. enteritidis
ser. montevideo were grown in composted sewage sludge to levels of approximately 10
9
/g. These bacteria were found to be inactivated by ionizing radiation at approximately the same rate (30 krads/log) as
Salmonella
species in liquid digested sludge.
Characteristics of Bacteroides isolates from the cecum of conventional mice
Authors: Tannock G W
Published: January 2020

Bacteroides isolates from the cecum of conventional mice were characterized and grouped according to their ability to ferment or hydrolyze carbohydrates and other compounds believed to be present in the intestinal ecosystem. The isolates were divided into 11 groups on the basis of the fermentation of glucose, cellobiose, gum arabic and xylan (hemicelluloses), N-acetylglucosamine, and dextrin; the hydrolysis of starch and casein (proteolysis); and the production of indole. Stock cultures of B. fragilis, B. distasonis, B. ovatus, B. vulgatus, and B. ruminicola were characterized in the same way. The strains isolated most frequently from the mouse cecum resembled B. fragilis (except that arabinose was fermented) and B. thetaiotaomicron.
Salmonella in surface waters of central New York state
Authors: Dondero N C , Thomas C T , Khare M , Timoney J F , Fukui G M
Published: January 2020

Six tributary streams and southern Cayuga Lake in central New York state were sampled for the presence of Salmonella on swabs immersed for 4 days. Of a total of 322 swabs, 39% yielded salmonellae. Swabs were cultured in tetrathionate enrichment at 41.5 degrees C. Isolations were made from brilliant green agar. Salmonellae were isolated from many sites on the streams and from some lake sites. Twenty-five serotypes (11 somatic antigen groups) and a distinct biotype of S. typhimurium (H2S negative) were found. Most frequent isolates, in order of decreasing occurrence, were S. typhimurium, S. thompson, S. oranienburg, and S. enteritidis. Several uncommon isolates also appeared. When tested for mouse infectivity, the isolates generally showed little or no virulence. The incidence of clinical salmonellosis among humans was low in the area and the variety of serotypes had not been noted among cattle. The presence of Salmonella in waters ranging in classification from potable to agricultural and industrial indicated the existence of a low level and undefined reservoirs of the bacteria in the region.
Exponential growth kinetics for Polyporus versicolor and Pleurotus ostreatus in submerged culture
Authors: Carroad P A , Wilde C R
Published: January 2020

Simple mathematical models for a batch culture of pellet-forming fungi in submerged culture were tested on growth data for Polyporus versicolor (ATCC 12679) and Pleurotus ostreatus (ATCC 9415). A kinetic model based on a growth rate proportional to the two-thirds power of the cell mass was shown to be satisfactory. A model based on a growth rate directly proportional to the cell mass fitted the data equally well, however, and may be preferable because of mathematical simplicity.
Growth and cell volume of Euglena gracilis in different media
Authors: Shehata T E , Kempner E S
Published: January 2020

It is necessary to propagate Euglena gracilis cells for several days after transfer from one medium to another to establish the steady state of balanced growth. Steady-state growth was established in minimal and in complex medium. Specific growth rates and cell volume distributions were computed for each culture medium. Mean cell volume of E. gracilis is not uniquely correlated with the specific growth rate.
Oxidative coupling of aromatic pesticide intermediates by a fungal phenol oxidase
Authors: Sjoblad R D , Bollag J M
Published: January 2020

The soil fungus Rhizoctonia praticola produced an enzyme that accumulated in the growth medium and caused the polymerization of phenolic and naphtholic intermediates of various pesticides. The dialyzed crude enzyme was purified by ion-exhange column chromatography with diethylaminoethyl-cellulose, followed by gel filtration with Sephadex G-200. The enzyme, a phenol oxidase, was capable of polymerizing 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, and 4-bromo-2-chlorophenol. 1-Naphthol, 2-naphthol, and some of their derivatives formed oligomers or polymers when incubated with the enzyme, but 4-nitrophenol and 2,4-dinitriphenol were not oxidized. Chlorinated and brominated anilines, which are derivatives of herbicides, were not altered by the phenol oxidase from R. praticola, but 4-methoxyaniline was transformed by the enzyme to 2-amino-5-p-anisidinobenzoquinone-di-p-methoxyphenylimine. The formation of polymeric products was determined by mass spectrometric analysis.
Nitrification in histosols: a potential role for the heterotrophic nitrifier
Authors: Tate R L
Published: January 2020

Insufficient populations of Nitrosomonas and Nitrobacter were found in a Pahokee muck soil (Lithic medidaprit) to account for the nitrate concentration observed. To determine if heterotrophic nitrifiers could account for some of this discrepancy, a method was developed to measure the levels of heterotrophic nitrifiers in soil. A population of 4.1 X 10(5) Arthrobacter per g of dry fallow soil, capable of producing nitrite and/or nitrate from reduced nitrogenous compounds, was observed. Amendment of the much with 0.5% (wt/wt) sodium acetate and 0.1% (wt/wt) ammonium-nitrogen as ammonium sulfate (final concentrations) not only resulted in the usual increase in autotrophic nitrifiers, but also in a fourfold increase in the heterotrophic nitrifying Arrthrobacter. Amendment of like samples with N-Serve [2-chloro-6(trichloromethyl) pyridinel] prevented the increase in Nitrosomonas, but not that in the heterotrophic nitrifiers. Nitrate production in the presence of the inhibitor was diminished but not prevented. An Arthrobacter sp., isolated from the muck, produced nitrite when inoculated at high densities into sterile soil, unamended or amended with sodium acetate and/or ammomium sulfate. These data suggest that the heterotrophic population may be responsible for some of the nitrate produced in these Histosols.
Construction of a Kit of Reference Strains for Rapid Genetic Mapping in
Bacillus subtilis
168
Authors: Dedonder R. A. , Lepesant J-A. , Lepesant-Kejzlarová J. , Billault A. , Steinmetz M. , Kunst F.
Published: January 2020

A set of nine reference strains bringing convenient markers in the genetic background of
Bacillus subtilis
Marburg 168 has been prepared to allow rapid mapping of new markers.
Bacterial metabolism of quaternary ammonium compounds
Authors: Dean-Raymond D , Alexander M
Published: January 2020

Of 10 quaternary ammonium compounds tested for biodegradation by the biological oxygen demand technique, only decyl- and hexadecyltrimethylammonium bromides were decomposed by organisms derived from sewage and soil. A mixture consisting of individual strains of Pseudomonas and Xanthomonas grew in solutions containing decyltrimethylammonium bromide as sole carbon source. The xanthomonad metabolized this quaternary ammonium compound in the presence of other organic molecules. The products of this activity included 9-carboxynomyl- and 7-carboxyheptyltrimethylammonium, suggesting that the terminal carbon of the decyl moiety is oxidized and the resulting carboxylic acid is subject to beta-oxidation.
Growth of Desulfovibrio in Lactate or Ethanol Media Low in Sulfate in Association with H
2
-Utilizing Methanogenic Bacteria
Authors: Bryant M. P. , Campbell L. Leon , Reddy C. A. , Crabill M. R.
Published: January 2020

In the analysis of an ethanol-CO
2
enrichment of bacteria from an anaerobic sewage digestor, a strain tentatively identified as
Desulfovibrio vulgaris
and an H
2
-utilizing methanogen resembling
Methanobacterium formicicum
were isolated, and they were shown to represent a synergistic association of two bacterial species similar to that previously found between S organism and
Methanobacterium
strain MOH isolated from
Methanobacillus omelianskii.
In lowsulfate media, the desulfovibrio produced acetate and H
2
from ethanol and acetate, H
2
, and, presumably, CO
2
from lactate; but growth was slight and little of the energy source was catabolized unless the organism was combined with an H
2
-utilizing methanogenic bacterium. The type strains of
D. vulgaris
and
Desulfovibrio desulfuricans
carried out the same type of synergistic growth with methanogens. In mixtures of desulfovibrio and strain MOH growing on ethanol, lactate, or pyruvate, diminution of methane produced was stoichiometric with the moles of sulfate added, and the desulfovibrios grew better with sulfate addition. The energetics of the synergistic associations and of the competition between the methanogenic system and sulfate-reducing system as sinks for electrons generated in the oxidation of organic materials such as ethanol, lactate, and acetate are discussed. It is suggested that lack of availability of H
2
for growth of methanogens is a major factor in suppression of methanogenesis by sulfate in natural ecosystems. The results with these known mixtures of bacteria suggest that hydrogenase-forming, sulfate-reducing bacteria could be active in some methanogenic ecosystems that are low in sulfate.
Methyl bromide as a microbicidal fumigant for tree nuts
Authors: Schade J E , King A D
Published: January 2020

Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues. Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues. Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99%. Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant. Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control.
Lactobacilli isolated from the stomach of conventional mice
Authors: Roach S , Savage D C , Tannock G W
Published: January 2020

Twenty strains of lactobacilli isolated from the stomach of conventional mice were tested for their ability to ferment or hydrolyze substrates that may be present in the stomach habitat. The lactobacilli could be placed in four groups (A to D) depending on their ability to ferment N-acetylglucosamine, dextrin, cellobiose, gum arabic, and xylan. The majority of the isolates belonged to groups A and D. Group A strains did not resemble previously described Lactobacillus species, but group D strains were identified as L. leichmannii. A representative group A isolate colonized the surface of the nonsecretory epithelium of the stomach of gnotobiotic mice; a group D isolate did not.
Serial propagation of Pneumocystis carinii in cell line cultures
Authors: Latorre C R , Sulzer A J , Norman L G
Published: January 2020

Pneumocystis carinii was propagated on three cell lines routinely cultured in many laboratories; the method is practical and convenient. Organisms produced were found to be reactive to Pneumocystis antisera. Studies of antigenic relationships, life cycles, and diagnostic methods will be made easier by these cultures.
Gentle Lysis of
Staphylococcus aureus
at Low Temperature
Authors: Flowers Russell S. , Martin Scott E. , Ordal Z. John
Published: January 2020

A low-temperature lysis procedure for
Staphylococcus aureus
is described. It is simple and requires no special equipment.
Changes in lipid composition of Escherichia coli resulting from growth with organic solvents and with food additives
Authors: Ingram L O
Published: January 2020

Cells of Escherichia coli contain an altered fatty acid and phospholipid composition when grown in the presence of sublethal concentrations of a variety of organic solvents and food additives. The diversity of compounds examined which caused these changes indicates that no single catabolic pathway is involved. Many of the observed changes are consistent with the hypothesis that cells adapt their membrane lipids to compensate for the presence of these compounds in the environment. Both sodium benzoate and calcium propionate caused the synthesis of unusual fatty acids.
Response of Microorganisms to an Accidental Gasoline Spillage in an Arctic Freshwater Ecosystem
Authors: Horowitz A. , Atlas R. M.
Published: January 2020

The response of microorganisms to an accidental spillage of 55,000 gallons of leaded gasoline into an Arctic freshwater lake was studied. Shifts in microbial populations were detected after the spillage, reflecting the migration pattern of the gasoline, enrichment for hydrocarbon utilizers, and selection for leaded-gasoline-tolerant microorganisms. Ratios of gasoline-tolerant/utilizing heterotrophs to “total” heterotrophs were found to be a sensitive indicator of the degree of hydrocarbon contamination. Respiration rates were elevated in the highly contaminated area, but did not reflect differences between moderately and lightly contaminated areas. Hydrocarbon biodegradation potential experiments showed that indigenous microorganisms could extensively convert hydrocarbons to CO
2
. In situ measurement of gasoline degradation showed that, if untreated, sediment samples retained significant amounts of gasoline hydrocarbons including “volatile components” at the time the lake froze for the winter. Nutrient addition and bacterial inoculation resulted in enhanced biodegradative losses, significantly reducing the amount of residual hydrocarbons. Enhanced biodegradation, however, resulted in the appearance of compounds not detected in the gasoline. Since the contaminated lake serves as a drinking water supply, treatment to enhance microbial removal of much of the remaining gasoline still may be advisable.
Baked-Bean Waste: a Potential Substrate for Producing Fungal Amylases
Authors: Hang Y. D. , Woodams E. E.
Published: January 2020

Baked-bean waste was found to be a favorable substrate for amylase production by
Aspergillus foetidus
NRRL 337. Under optimum conditions, the yields of α-amylase (EC 3.2.1.1) and glucoamylase (EC 3.2.1.3) were 47 and 226 U, respectively, per ml of the waste fermented.
Uptake of glucose and maltose by Bacillus popillae
Authors: Taylor D C , Costilow R N
Published: January 2020

Results of experiments with glucose and its analog, methyl alpha-D-glucopyranoside, indicated that when glucose was present at low concentrations, it was transported into Bacillus popilliae NRRL B-2309MC cells as glucose 6-phosphate by a phosphoenolpyruvate:sugar phosphotransferase system. An additional mode(s) of entry may be operative at higher glucose concentrations. Maltose appeared to enter the cells by a nonphosphorylative process and was hydrolyzed intracellularly to glucose. No phosphoryl donor was necessary for this hydrolysis.
Aflatoxin in corn: ammonia inactivation and bioassay with rainbow trout
Authors: Brekke O L , Sinnhuber R O , Peplinski A J , Wales J H , Putnam G B , Lee D J , Ciegler A
Published: January 2020

Four samples of corn were compared with respect to their hepatocarcinogenicity in rainbow trout. One corn sample was found by chemical analysis to contain no detectable aflatoxin. A second sample was contaminated with aflatoxins at a level of 180 microgram/kg. Each of the above-mentioned samples was divided, and one-half of each was ammoniated. These four samples were added to a semipurified basal diet and fed to a sensitive strain of rainbow trout. It was found that ammoniation inactivated the aflatoxins and reduced the carcinogenicity of the contaminated corn to a level that was not significantly different from that with the basal control diet. It was also found that the ammoniation process did not reduce the nutritive value of the corn.
Membrane Filter Technique for the Quantification of Stressed Fecal Coliforms in the Aquatic Environment
Authors: Stuart David G. , McFeters Gordon A. , Schillinger John E.
Published: January 2020

A two-layer membrane filtration (MF) medium (injury-mitigating MF [IM-MF]) and a procedure for the enumeration of injured fecal coliforms are described. These procedures included the addition of glycerol and acetate plus reducing agents to both layers of a two-layer medium and rinsing of the filter with a rich resuscitation medium. Some changes in incubation time and temperatures were used. This method was compared with the multiple-tube fermentation most-probable-number procedure and the one-step M-FC agar-membrane filter method (direct M-FC) in terms of fecal coliform recovery from various aquatic environments that cause bacterial injury. With chlorinated sewage effluents, results of the IM-MF technique were equal to or greater than the most probable number in 9 of 18 trials and were 1.3 to 19 times greater than the M-FC method. When sewage samples were chlorinated in the laboratory, fecal coliform counts with IM-MF equaled or exceeded the most probable number in 7 of 15 trials and always exceeded the M-FC. M-FC was exceeded by IM-MF in 30 of 33 trials with clean mountain stream water. Fecal coliform bacteria that were exposed to low levels of an iodophore in the laboratory produced IM-MF counts 3 to 10 times greater than those with M-FC. A biochemical rationale for the formation of the IM-MF medium is discussed.
Epoxidation of 1,7-octadiene by Pseudomonas oleovorans: fermentation in the presence of cyclohexane
Authors: Schwartz R D , McCoy C J
Published: January 2020

A very efficient conversion of 1,7-octadiene to 7,8-epoxy-1-octene and 1,2-7,8-diepoxyoctane was achieved by incorporating a high concentration of cyclohexane into the conventional fermentation medium. In the presence of cyclohexane, a 90-ml% conversion of substrate to product was accomplished within 72 h, compared with an 18,5-mol% conversion in the absence of cyclohexane. Furthermore, the products were simultaneously separated and concentrated in the organic phase.
Inheritance and longevity of infectious pancreatic necrosis virus in the zebra fish, Brachydanio rerio (Hamilton-Buchanan)
Authors: Seeley R J , Perlmutter A , Seeley V A
Published: January 2020

Zebra fish (Brachydanio rerio) were injected with infectious pancreatic necrosis virus (IPNV) and then spawned to determine whether the virus was passed on to the eggs, and if it was, how long it remained in the free-swimming F1. The mating variations included parents receiving one or two injections of virus, and within these categories, matings in which both parents were treated or only one parent was treated. The results showed that transmission of IPNV to the egg did occur, and that this transmission was via the female alone. However, if the female was allowed to produce antibodies to the virus, as when she received two injections of IPNV, she transmitted the virus to the eggs for only a short period of time. In addition, when the virus was transmitted to the egg, it remained in the free-swimming F1 for a period of at least 5 months.
Sublethal cold shock in Vibrio parahaemolyticus
Authors: van den Broek M J , Mossel D A
Published: January 2020

Exposing Vibrio parahaemolyticus populations to temperatures of 2 degrees C results in membrane damage, rendering cells incompetent to grow on media containing 5% NaCl.
Seasonal distribution of vitamin B12 in Lake Kinneret
Authors: Cavari B , Grossowicz N
Published: January 2020

Vitamin B12 is formed in Lake Kinneret in the hypolimnion and in the sediment. The highest value of B12 recorded in the lake water was about 100 ng/liter in November and December of 1975 at a 40-m depth. The vitamin was liberated from the hypolimnion during the turnover period. This supply of the vitamin to the photic zone was accompanied by increasing biomass of Dinoflagellates, Bacillariophyta, and Chlorophyta. The decrease in the vitamin concentration, followed by an increase, is correlated with a decline and subsequent rise in the algal biomass, respectively. Cyanophyta biomass, on the other hand, increased when the vitamin concentration in the photic zone was at its lowest level.
Rapid detection and quantitation of Clostridium perfringens enterostoxin by counterimmunoelectrophoresis
Authors: Naik H S , Duncan C L
Published: January 2020

Conditions for detection and quantitation of Clostridium perfringens enterotoxin by counterimmunoelectrophoresis are described. As little as 0.2 microgram of enterotoxin per ml could be detected. The test was found to be rapid, sensitive, specific and easy for the detection and quantitation of enterotoxin.
Dry-heat resistance of selected psychrophiles
Authors: Winans L , Pflug I J , Foster T L
Published: January 2020

The dry-heat resistance characteristics of spores of psychrophilic organisms isolated from soil samples from the Viking spacecraft assembly areas at Cape Kennedy Space Flight Center, Cape Canaveral, Fla., were studied. Spore suspensions were produced, and dry-heat D values were determined for the microorganisms that demonstrated growth or survival under a simulated Martian environment. The dry-heat tests were carried out by using the planchet-boat-hot plate system at 110 and 125 degrees C with an ambient relative humidity of 50% at 22 degrees C. The spores evaluated had a relatively low resistance to dry heat. D(110 degrees C) values ranged from 7.5 to 122 min, whereas the D(123 degrees C) values ranged from less than 1.0 to 9.8 min.
Production of beta-galactosidase from Streptococcus thermophilus grown in whey
Authors: Rao M V , Dutta S M
Published: January 2020

beta-D-Galactosidase (EC 3.2.1.23) was extracted from Streptococcus thermophilus grown in deproteinized cheese whey. Cultural conditions optimum for maximum enzyme production were pH 7.0, 40 degrees C, and 24 h. Proteose peptone (2.0%, wt/vol) and corn steep liquor (2.8%, wt/vol) were highly stimulatory, increasing the enzyme units available in their absence from 660 U/liter of medium to 18,200 and 10,000 U/liter of medium, respectively, in their presence. There was an insignificant increase in the production of enzyme in the presence of added inorganic nitrogen and phosphorus sources. Enzymatic hydrolysis for recuction of lactose content in aqueous solution and in skim milk was studied.
Increased spore yields of Clostridium perfringens in the presence of methylxanthines
Authors: Sacks L E , Thompson P A
Published: January 2020

The methylxanthines caffeine, theophylline, and isobutylmethylxanthine greatly increased spore yields of Clostridium perfringens strains FD-1, PS52, and PS49 when grown on Duncan-Strong medium or on a new casein-digest medium. Four other strains (KA3, and National Collection of Type Cultures strains 8798, 8238, and 10240) failed to show any significant increase when tested under similar conditions. The degree of sporulation increase was influenced by the carbohydrate energy source in some strains but not in others. Strain PS52 showed a large increase in spore yield when dextrin was the energy source but only a slight increase when raffinose served as the energy source. Strain FD-1 showed similar increases in spore yield with either dextrin or raffinose.
Bacterial Association in the Gastrointestinal Tract of Beagle Dogs
Authors: Davis C. P. , Cleven D. , Balish E. , Yale C. E.
Published: January 2020

Nine male beagle dogs, housed in either a conventional or locked environment for 2.5 years, were killed, and the bacterial flora present in various regions of each gastrointestinal tract was assessed by culture techniques, light microscopy, and scanning electron microscopy. All dogs possessed a complex microflora in their colons; in almost every dog anaerobes predominated. The highest number of bacteria cultured was 10
10
/g (dry weight) of tissue and contents; highest counts obtained with a Petroff-Hauser counting chamber were 10
10
/ml (wet weight). Although there was a consistency in the detectable genera, there were also noticeable differences in the flora of dogs housed under different environmental conditions. These differences included qualitative and quantitative changes in the flora as well as alterations in the distribution and localization of microorganisms along the gastrointestinal tract and in the crypts of Lieberkuhn. No bacterial layers were detected on the surfaces of stomach or proximal bowel in any of the dogs. Dogs housed in a conventional, open, environment had bacteria that occurred in layers on their ceca and colons and in their crypts of Lieberkuhn; however, dogs housed under “locked” environmental conditions did not possess them or had them less frequently. Dogs removed from the locked environment and kept (30 days) in conventional housing conditions were the only ones with detectable segmented filamentous microbes in their ilea. This study shows that the microbial flora does not simplify when dogs are housed in a locked environment. Indeed, it may increase in complexity and cause alterations in the bacterial flora that is associated closely with gastrointestinal epithelial cells and crypts of Lieberkuhn.
Ethylene Production by Axenic Fruiting Cultures of
Agaricus bisporus
Authors: Wood D. A. , Hammond J. B. W.
Published: January 2020

Axenic cultures of
Agaricus bisporus
were used to show that the rise in ethylene production during fruiting derives from its own metabolism.
Fermentation of cellulose by Ruminococcus flavefaciens in the presence and absence of Methanobacterium ruminantium
Authors: Latham M J , Wolin M J
Published: January 2020

The anaerobic cellulolytic rumen bacterium Ruminococcus flavefaciens normally produces succinic acid as a major fermentation product together with acetic and formic acids, H2, and CO2. When grown on cellulose and in the presence of the methanogenic rumen bacterium Methanobacterium ruminantium, acetate was the major fermentation product; succinate was formed in small amounts; little formate was detected; H2 did not accumulate; and large amounts of CH4 were formed. M. ruminantium depends for growth on the reduction of CO2 to CH4 by H2, which it can obtain directly or by producing H2 and CO2 from formate. In mixed culture, the methanobacterium utilized the H2 and possibly the formate produced by the ruminococcus and in so doing stimulated the flow of electrons generated during glycolysis by the ruminococcus toward H2 formation and away from formation of succinate. This type of interaction may be of significance in determining the flow of cellulose carbon to the normal rumen fermentation products.
Distribution of Myxobacters in Aquatic Habitats of an Alkaline Bog
Authors: Hook Leonard A.
Published: January 2020

Ten species of myxobacteria were identified from samples from an alkaline bog and adjacent soils. The frequency of occurrence and the diversity of species were highest at the margin of the bog and were lowest in the center and bottom of the bog lake.
Metabolism of quaternary carbon compounds: 2,2-dimethylheptane and tertbutylbenzene
Authors: Catelani D , Colombi A , Sorlini C , Treccani V
Published: January 2020

Two Achromobacter strains capable of utilizing 2,2-dimethylheptane or tertbutylbenzene as the sole carbon and energy source were isolated from waste-water. Pivalic acid was found in the cultures of Achromobacter A1 containing 2,2-dimethylheptane. From cultures of Achromobacter A2 in the presence of tertbutylbenzene, a diol was isolated and identified as 2,3-dihydro-2,3-dihydroxytertbutylbenzene. Evidence for meta cleavage of the aromatic ring and for accumulation of pivalic acid in the cultures was also obtained. A metabolic pathway for tertbutylbenzene is suggested.
Comparison of four-hour and twenty-four-hour refrigerated storage of nonpotable water for fecal coliform analysis
Authors: Standridge J H , Lesar D J
Published: January 2020

The problem of extending the storage time of water samples for fecal coliform analysis was addressed. Included in this report is a literature review of the storage problem. Twenty-eight samples were analyzed in replicate to determine the effect of 24-h storage of water samples at 4 degrees C. A new statistical approach to data analysis, coupled with the concept of practical acceptability, is presented. According to our results, many samples can successfully be stored at 4 degrees C for 24 h.
Bacterial lipopolysaccharides as inducers of disease resistance in tobacco
Authors: Graham T L , Sequeira L , Huang T S
Published: January 2020

The cell wall component of Pseudomonas solanacearum that induces disease resistance in tobacco was highly heat stable at neutral or alkaline pH but highly labile at acid pH. Activity was unaffected by nucleases and proteases but destroyed by a mixture of beta-glycosidases. Washing of bacterial cell walls released a lipopolysaccharide (LPS) fraction with high inducer activity. Purified LPS, extracted by a variety of procedures from whole cells, isolated cell walls, and culture filtrates of both smooth and rough forms of P. solanacearum, induced disease resistance in tobacco at concentrations as low as 50 microgram/ml. The LPS from the non-plant pathogens Escherichia coli B, E. coli K, and Serratia marcescens was also active. Cell wall protein, free phospholipid, and nucleic acids were not necessary for activity. Moreover, since LPS from rough forms was active, the O-specific polysaccharide of the LPS was not required for activity. Hydrolysis of the remaining core-lipid A linkage or deacylation of lipid A destroyed inducer activity. When injected into tobacco leaves, purified LPS attached to tobacco mesophyll cell walls and induced ultrastructural changes in the host cell similar to those induced by attachment of whole heat-killed bacteria.
L-Histidine production by histidase-less regulatory mutants of Serratia marcescens constructed by transduction
Authors: Kisumi M , Nakanishi N , Takagi T , Chibata I
Published: January 2020

2-Methylhistidine (2MH) and 1,2,4-triazole-3-alanine (TRA) inhibited the growth of Serratia marcescens. These inhibitory effects were counteracted by L-histidine. Enzymatic studies showed that 2MH acts as a false feedback inhibitor and TRA acts as both a false feedback inhibitor and a repressor. Mutants resistant to each analog were isolated from a histidase-less mutant, because the wild-type strain possesses a potent histidase activity. 2MH-resistant mutants had a feedback-insensitive phosphoribosyltransferase, but they produced only small amounts of L-histidine. TRA-resistant mutants were divided into two types according to their histidine productivity. A mutant of one type produced about 8 mg of L-histidine per ml and had about a 10-fold increase in the enzyme levels of histidine biosynthesis. Moreover, this mutant had a partially feedback-insensitive phosphoribosyltransferase. A mutant of the second type produced only a small amount of L-histidine and had only derepressed enzyme levels. Accordingly, strains possessing the genetic alterations in both 2MH- and TRA-resistant mutants were constructed by PS20-mediated transduction. They had both feedback-insensitive phosphoribosyltransferase and derepressed enzyme levels. The representative strain HT-2604 produced about 17 mg of L-histidine per ml.
Anaerobic and Aerobic Hydrogen Gas Formation by the Blue-Green Alga
Anabaena cylindrica
Authors: Daday Arlene , Platz Rosalea A. , Smith Geoffrey D.
Published: January 2020

An investigation was made of certain factors involved in the formation of hydrogen gas, both in an anaerobic environment (argon) and in air, by the blue-green alga
Anabaena cylindrica.
The alga had not been previously adapted under hydrogen gas and hence the hydrogen evolution occurred entirely within the nitrogen-fixing heterocyst cells; organisms grown in a fixed nitrogen source, and which were therefore devoid of heterocysts, did not produce hydrogen under these conditions. Use of the inhibitor dichlorophenyl-dimethyl urea showed that hydrogen formation was directly dependent on photosystem I and only indirectly dependent on photosystem II, consistent with heterocysts being the site of hydrogen formation. The uncouplers carbonyl cyanide chlorophenyl hydrazone and dinitrophenol almost completely inhibited hydrogen formation, indicating that the process occurs almost entirely via the adenosine 5′-triphosphate-dependent nitrogenase. Salicylaldoxime also inhibited hydrogen formation, again illustrating the necessity of photophosphorylation. Whereas hydrogen formation could usually only be observed in anaerobic, dinitrogen-free environments, incubation in the presence of the dinitrogen-fixing inhibitor carbon monoxide plus the hydrogenase inhibitor acetylene resulted in significant formation of hydrogen even in air. Hydrogen formation was studied in batch cultures as a function of age of the cultures and also as a function of culture concentration, in both cases the cultures being harvested in logarithmic growth. Hydrogen evolution (and acetylene-reducing activity) exhibited a distinct maximum with respect to the age of the cultures. Finally, the levels of the protective enzyme, superoxide dismutase, were measured in heterocyst and vegetative cell fractions of the organism; the level was twice as high in heterocyst cells (2.3 units/mg of protein) as in vegetative cells (1.1 units/mg of protein). A simple procedure for isolating heterocyst cells is described.
Bdellovibrio and the intestinal flora of vertebrates
Authors: Westergaard J M , Kramer T T
Published: January 2020

Bdellovibrio strain MS7 force-fed to fish and frogs via an intragastric tube did not become an integral component of the intestinal microflora. Strain MS7 fed to mice in drinking water was not recovered from the intestinal tract of mice. However, in vitro, the organism multiplied in intestinal contents of frogs and mice. Bdellovibrio inoculated into rabbit ileal loops was greatly reduced in number within 24 h. It was concluded that strains MS7 could be considered nonpathogenic to animals, at least when introduced into the digestive tract, and that it is not feasible at the present time to lyse pathogenic, gram-negative bacteria in the alimentary tract with Bdellovibrio.
Double-antibody solid-phase enzyme immunoassay for the detection of staphylococcal enterotoxin A
Authors: Saunders G C , Bartlett M L
Published: January 2020

A simple double-antibody enzyme immunoassay that uses a microtechnique was developed for detecting staphylococcal enterotoxin A in food products. Sample preparation can be completed in less than 15 min. Assay sensitivity ranges from 0.4 ng (20-h test time) to 3.2 ng (1- to 3-h test time) of toxin per ml of prepared sample. Separation and detection of enterotoxin from spiked food products ranged between 72 and 98% of the amount added.
Fermentation of mucins and plant polysaccharides by anaerobic bacteria from the human colon
Authors: Salyers A A , West S E , Vercellotti J R , Wilkins T D
Published: January 2020

A total of 154 strains from 22 species of Bifidobacterium, Peptostreptococcus, Lactobacillus, Ruminococcus, Coprococcus, Eubacterium, and Fusobacterium, which are present in high concentrations in the human colon, were surveyed for their ability to ferment 21 different complex carbohydrates. Plant polysaccharides, including amylose, amylopectin, pectin, polygalacturonate, xylan, laminarin, guar gum, locust bean gum, gum ghatti, gum arabic, and gum tragacanth, were fermented by some strains from Bifidobacterium, Peptostreptococcus, Ruminococcus, and Eubacterium species. Porcine gastric mucin, which was fermented by some strains of Ruminococcus torques and Bifidobacterium bifidum, was the only mucin utilized by any of the strains tested.
Role of estrogen in controlling the genital microflora of female rats
Authors: Larsen B , Markovetz A J , Galask R P
Published: January 2020

Plate counts of viable bacteria recovered by lavage from rat vaginae demonstrated that the number of bacteria associated with the vaginal epithelium varied cyclically and that this pattern was abolished by ovariectomy. After ovariectomy, vaginal bacterial counts remained relatively stable at low levels. The estrogen 17beta-estradiol (1,3,5(10)-estratriene-3,17beta-diol cypionate) administered to ovariectomized rats caused a significant increase in vaginal bacterial counts on day 3 post-treatment. A similar effect was seen in non-ovariectomized rats, but a larger dose of estrogen antagonist may have been present in non-ovariectomized animals. Progesterone (4-pregnene-3,20-dione) given with estradiol diminished the effect of the estrogen on vaginal bacterial counts, but did not abolish it. Progesterone administered without estradiol had no detectable effect on vaginal bacterial counts. These findings suggested that the cyclic variation in bacterial content of rat vaginae could be explained primarily as the effect of the secretory pattern of ovarian estrogen.