bluuebunny/crossref_metadata_2025 huggingface dataset:
Types and Distribution of Anaerobic Bacteria in the Large Intestine of Pigs
Authors: Russell Edward G.
Published: January 2020

An examination was made of various sites along the length of the swine large intestine, using strictly anaerobic culture methods. Sites were separated by differential washing into fractions described as lumenal content, lumenal surface layer, and intestinal wall tissue. Direct microscopic clump counts averaged 13.3 × 10
10
organisms per g (dry weight) of material in the lumenal content, 14.0 × 10
10
in the surface layer, and 5.1 × 10
10
in the intestinal wall tissue. Both direct microscopic counts and viable culture counts were higher from the lumenal content and surface layer than from the intestinal tissue at all sites sampled in the intestine. Cultural counts averaged 56.2% of the direct microscopic counts in lumenal content and surface layer and 20.2% in intestinal tissue. Over 90% of the bacteria isolated were gram positive and consisted mainly of gram-positive cocci, lactobacilli, eubacteria, and clostridia. Of 192 isolates recovered, only 124 could be assigned to recognized species.
Clostridium botulinum in the Gulf of Thailand
Authors: Tanasugarn L
Published: January 2020

A survey was carried out to determine the incidence of Clostridium botulinum in samples of mud, sand, and fish from the Gulf of Thailand. Enrichment cultures from 762 samples of mud and sand from seven different areas around the Gulf were tested. C. botulinum type D was present in 10 samples, and type E was present in 2 samples taken from the west coast at Hua Hin. Enrichment cultures from 16,773 fish grouped into 2,151 samples yielded 10 filtrates containing C. botulinum type D and 5 containing type E. All of the toxic filtrates were obtained from samples of fish taken from the west coast of the Gulf of Thailand.
Convenient procedures for the biosynthesis, isolation, and isotope labeling of cytochalasins
Authors: Zabel R A , Miller C A , Tanenbaum S W
Published: January 2020

Efforts to improve small-scale yields of useful cytochalasins by fermentation resulted in selection of an enriched aflatoxin medium which increased yields by fivefold over those reported in the literature. With Helminthosporium dematoideum and Zygosporium masonii in stationary culture for 3 weeks, cytochalasins B and D were obtained in quantities approaching 700 and 500 mg/liter, respectively. It appears that the critical component in this growth medium is factors associated with whole wheat. By using these procedures, coupled with improvements in isolation, supplementation with two radioactive phenylalanine species readily produced [14C]- or [3H]cytochalasin B. Oxidation of carrier-free radioactive cytochalasin B to cytochasasin A readily provided this labeled congener as well. The isotopic ocnversion of precursor to crystalline products that met analytical criteria ranged from 2 to 4% of the administered radioactivity.
Microbial Methanogenesis and Acetate Metabolism in a Meromictic Lake
Authors: Winfrey M. R. , Zeikus J. G.
Published: January 2020

Methanogenesis and the anaerobic metabolism of acetate were examined in the sediment and water column of Knaack Lake, a small biogenic meromictic lake located in central Wisconsin. The lake was sharply stratified during the summer and was anaerobic below a depth of 3 m. Large concentrations (4,000 μmol/liter) of dissolved methane were detected in the bottom waters. A methane concentration maximum occurred at 4 m above the sediment. The production of
14
CH
4
from
14
C-labeled HCOOH, HCO
3
−
, and CH
3
OH and [2-
14
C]acetate demonstrated microbial methanogenesis in the water column of the lake. The maximum rate of methanogenesis calculated from reduction of H
14
CO
3
−
by endogenous electron donors in the surface sediment (depth, 22 m) was 7.6 nmol/h per 10 ml and in the water column (depth, 21 m) was 0.6 nmol/h per 10 ml. The methyl group of acetate was simultaneously metabolized to CH
4
and CO
2
in the anaerobic portions of the lake. Acetate oxidation was greatest in surface waters and decreased with water depth. Acetate was metabolized primarily to methane in the sediments and water immediately above the sediment. Sulfide inhibition studies and temperature activity profiles demonstrated that acetate metabolism was performed by several microbial populations. Sulfide additions (less than 5 μg/ml) to water from 21.5 m stimulated methanogenesis from acetate, but inhibited CO
2
production. Sulfate addition (1 mM) had no significant effect on acetate metabolism in water from 21.5 m, whereas nitrate additions (10 to 14,000 μg/liter) completely inhibited methanogenesis and stimulated CO
2
formation.
Limitations of the Moeller lysine and ornithine decarboxylase tests
Authors: Pilsucki R W , Clayton N W , Cabelli V J , Cohen P S
Published: January 2020

A total of 40 fecal and environmental isolates, including 26 Escherichia coli strains, 9 members of the genus Klebsiella, and 5 members of the genus Enterobacter, were tested by enzyme assay for their endogenous and induced levels of lysine decarboxylase and ornithine decarboxylase when grown in Moeller decarboxylase medium. All of the coliforms examined had measurable lysine decarboxylase and ornithine decarboxylase activities whether or not they were positive in the Moeller test. In general, the Moeller lysine decarboxylase test reflected the inducibility of lysine decarboxylase whereas the Moeller ornithine decarboxylase test did not relect the inducibility of ornithine decarboxylase. Neither test measured the amount of intracellular enzyme; rather, they indicated whether the amount of polyamine liberated was sufficient to raise the pH of the culture medium above 7. Changing the growth conditions (i.e., the concentrations of glucose, lysine, and amino acids other than lysine) greatly influenced the lysine decarboxylase activity in coliforms. The limitations on the interpretation of the Moeller test results are discussed.
Stability and viability of Neisseria gonorrhoeae in various solutions and buffers
Authors: Norrod P , Williams R P
Published: January 2020

The stability and viability of Neisseria gonorrhoeae WP (T4) was tested in a variety of buffers and solutions, many of which are commonly used in gonococcal research. Each solution was tested at room temperature for its ability to maintain stability and viability of gonococci in concentrated suspensions and to maintain viability of gonococci in dilute suspensions. The 14 buffers and solutions tested could be divided into four groups based upon these criteria. Only a few solutions satisfied all three criteria. Of those tested, Gey salt solution and bovine serum albumin (0.01%) and proteose peptone (1%) in saline were the only two in which the gonococci retained viability in dilute suspensions for 25 min. Most of the solutions were not able to maintain viability of gonococci in dilute suspensions, even when the same solution was capable of maintaining stability and viability in concentrated suspensions.
Immobilization of Glucose Isomerase-Containing
Streptomyces phaeochromogenes
Cells in Fine-Particle Form
Authors: Kumakura Minoru , Yoshida Masaru , Kaetsu Isao
Published: January 2020

A new preparation method for immobilizing
Streptomyces phaeochromogenes
cells in fine-particle form was investigated using radiation-induced polymerization at low temperatures with previously salted out hydrophilic monomers. Using this method, it was found that the glucose isomerase activity of the immobilized cell particles was markedly higher than that of immobilized cells in block form obtained without salting out of the monomer. The diameter of the particles was varied by changing the irradiation temperature or the concentrations of monomer and salt. The magnitude of the enzymatic activity increased with decreasing particle diameter.
K

m

values of the immobilized cell particles were close to that of the intact cell. These facts suggested that the cells were trapped on the surface of the particle.
Characterization of Plasmid Deoxyribonucleic Acid in
Streptococcus lactis
subsp.
diacetylactis
: Evidence for Plasmid-Linked Citrate Utilization
Authors: Kempler G. M. , McKay L. L.
Published: January 2020

The use of
Streptococcus diacetylactis
as a flavor producer in dairy fermentations is dependent upon its ability to produce diacetyl from citrate. Treatment of
S. diacetylactis
strains 18-16 and DRC1 with acridine orange resulted in the conversion of approximately 2% of the DRC1 population and 20% of the 18-16 population to citrate negative, which is indicative of the involvement of plasmid deoxyribonucleic acid (DNA). Growth in the presence of acridine orange also resulted in the appearance of 2% lactose-negative derivatives in
S. diacetylactis
18-16 and 99% lactose-defective, proteinase-negative derivatives in
S. diacetylactis
DRC1. Cesium chloride-ethidium bromide equilibrium density gradients of cleared lysate material from each strain revealed the presence of covalently closed circular DNA. Samples of this covalently closed circular DNA were subjected to agarose gel electrophoresis to determine the plasmid composition of each strain.
S. diacetylactis
18-16 was found to possess six plasmids, of approximately 41, 28, 6.4, 5.5, 3.4, and 3.0 megadaltons (Mdal).
S. diacetylactis
DRC1 contained six plasmids, of approximately 41, 31, 18, 5.5, 4.5, and 3.7 Mdal. Variants of
S. diacetylactis
18-16 which failed to produce acetoin plus diacetyl from citrate (citrate negative) were missing a 5.5-Mdal plasmid. Lactose-negative mutants of the same strain were devoid of a 41-Mdal plasmid. Lactose-defective, proteinase-negative mutants of
S. diacetylactis
DRC1 were missing a 31-Mdal plasmid. The citrate-negative mutants of
S. diacetylactis
DRC1 isolated in this study did not possess a 5.5-Mdal plasmid. Thus, we have evidence that there is a correlation between the ability to utilize citrate and the presence of a 5.5-Mdal plasmid. A relationship was also noted between lactose fermentation and proteinase activity and plasmid DNA in
S. diacetylactis.
Production of Glucose Isomerase by
Streptomyces flavogriseus
Authors: Chen W. P. , Anderson A. W. , Han Y. W.
Published: January 2020

A microorganism that produces glucose isomerase was isolated from soil and identified as a strain of
Streptomyces flavogriseus
. The organism produced a large quantity of glucose isomerase when grown on straw hemicellulose, xylan, xylose, and H
2
SO
4
hydrolysate of ryegrass straw. The organism produced glucose isomerase both intra- and extra-cellularly. The highest level of intracellular glucose isomerase (3.5 U/ml) was obtained in about 36 h by a culture grown on straw hemicellulose; the extracellular enzyme (1.5 U/ml) appeared in cultures grown for about 72 h. About equal levels of enzyme were produced in cultures grown on straw hemicellulose, xylan, xylose, and H
2
SO
4
hydrolysate of straw, but production of the enzyme was drastically reduced when the organism was grown on other carbon sources. As a nitrogen source, corn steep liquor produced the best results. Soy flour extract, yeast extract, and various peptones also were adequate substrates for glucose isomerase production. Addition of Mg
2+
, Mn
2+
, or Fe
2+
to the growth medium significantly enhanced enzyme production. The organism, however, did not require Co
2+
, which is commonly required by microorganisms used in the production of glucose isomerase.
Mode of Attack on Orchardgrass Leaf Blades by Rumen Protozoa
Authors: Akin Danny E. , Amos Henry E.
Published: January 2020

Leaf blade sections of orchardgrass were incubated with rumen fluid and examined by scanning and transmission electron microscopy for the mode of attack on tissues by rumen protozoa. Rumen protozoa resembling
Epidinium ecaudatum
from
caudatum
degraded forage tissue in diluted, whole rumen fluid suspensions of microbes containing 1.6 mg of streptomycin per ml, which inhibited bacterial fiber-digesting activity. Cell walls of mesophyll, parenchyma bundle sheath, and epidermis became swollen and frayed to reveal a microfibrillar network and loss of electron density, indicating partial degradation. Then the protozoa ingested whole cells and fragments of cell walls with the aid of their cilia. Plant cells with partially degraded walls as well as chloroplasts without walls were present within the protozoa. These entodiniomorphs digested orchardgrass leaves by partially degrading the plant cell walls apparently by extracellular enzymes and then ingestion of the plant cells and cell wall fragments.
Spoilage of vacuum-packaged dark, firm, dry meat at chill temperatures
Authors: Gill C O , Newton K G
Published: January 2020

The flora of vacuum-packaged dark, firm, dry meat included thred organisms not usually found on vacuum-packaged meat, Yersinia enterocolitica, Enterobacter liquefaciens, and Alteromonas putrefaciens. Y. enterocolitica did not affect the meat quality. Production of spoilage odors by E. liquefaciens could be prevented by addition of glucose or citrate to the meat. Greening of meat could be prevented by addition of glucose or citrate to the meat. Greening of meat by A. putrefaciens was not prevented by addition of glucose, as the organism degraded cysteine with the release of H2S even when glucose was present. To prevent greening, growth of A. putrefaciens must be inhibited by reducing the meat pH to less than 6.0.
Emulsifier of Arthrobacter RAG-1: specificity of hydrocarbon substrate
Authors: Rosenberg E , Perry A , Gibson D T , Gutnick D L
Published: January 2020

The purified extracellular emulsifying factor produced by Arthrobacter RAG-1 (EF-RAG) emulsified light petroleum oil, diesel oil, and a variety of crude oils and gas oils. Although kerosine and gasoline were emulsified poorly by EF-RAG, they were converted into good substrates for emulsification by addition of aromatic compounds, such as 2-methylnaphthalene. Neither aromatic nor aliphatic fractions of crude oil were emulsified by EF-RAG; however, mixtures containing both fractions were emulsified. Pure aliphatic or aromatic hydrocarbons were emulsified poorly by EF-RAG. Binary mixtures containing an aliphatic and an aromatic hydrocarbon, however, were excellent substrates for EF-RAG-induced emulsification. Of a variety of alkylcyclohexane and alkylbenzene derivatives tested, only hexyl- or heptylbenzene and octyl- or decylcyclohexane were effectively emulsified by EF-RAG. These data indicate that for EF-RAG to induce emulsification of hydrocarbons in water, the hydrocarbon substrate must contain both aliphatic and cyclic components. With binary mixtures of methylnaphthalene and hexadecane, maximum emulsion was obtained with 25% hexadecane.
Bacteriocin production by Clostridium acetobutylicum in an industrial fermentation process
Authors: Barber J M , Robb F T , Webster J R , Woods D R
Published: January 2020

High titers of a noninducible bacteriocin were produced by Clostridium acetobutylicum in a molasses fermentation medium used for the industrial production of solvents. Release of the bacteriocin towards the end of the exponential growth phase was accompanied by lysis of the culture and inhibition of the production of solvents. The producer cells were sensitive to the bacteriocin, which only affected other C. acetobutylicum strains and a Clostridium felsineum strain. The thermolabile bacteriocin was not inactivated by protease enzymes and had no optimum stability between pH 4 and 5. The sedimentation coefficient of the bacteriocin was 6S.
Evidence for the subcellular localization and specificity of chlordane inhibition in the marine bacterium Aeromonas proteolytica
Authors: Nakas J P , Litchfield C D
Published: January 2020

Sublethal levels (10 to 100 micrograms/ml) of the chlorinated insecticide chlordane (1,2,4,5,6,7,8,8-octachloro-3a,4,7,7a-tetrahydro-4,7-methanoindan) were introduced into the growth medium of the marine bacterium, Aeromonas proteolytica. Chlordane inhibited the synthesis of an extracellular endopeptidase by almost 40% but exhibited no such inhibition of the extracellular aminopeptidase also produced during the growth cycle. Studied with 14C-labeled chlordane demonstrated that the insecticide was not biologically degraded under the test conditions used and that up to 75% of the recoverable chlordane was cell associated within 48 h. Studied with uniformly labeled L[14C]valine and [2-14C]uracil established that neither the transport nor the incorporation of these protein and ribonucleic acid precursors was inhibited by chlordane. Separation of the membrane fractions using isopycnic centrifugation localized 14C-labeled chlordane in the cytoplasmic membrane. Also, chlordane inhibited the membrane-bound adenosine 5'-triphosphatase while the soluble (released) form of this enzyme remained unaffected. These data indicate that chlordane resides in the cytoplasmic membrane and may cause specific alterations in membrane-associated activities.
Fourteen-year survival of Pseudomonas cepacia in a salts solution preserved with benzalkonium chloride
Authors: Geftic S G , Heymann H , Adair F W
Published: January 2020

A strain of Pseudomonas cepacia that survived for 14 years (1963 to 1977) as a contaminant in an inorganic salt solution which contained commercial 0.05% benzalkonium chloride (CBC) as an antimicrobial preservative, was compared to a recent clinical isolate of P. cepacia. Ammonium acetate was present in the concentrated stock CBC solution, and served as a carbon and nitrogen source for growth when carried over into the salts solution with the CBC. The isolate's resistance to pure benzalkonium chloride was increased step-wise to a concentration of 16%. Plate counts showed 4 x 10(3) colony-forming units per ml in the salts solution. Comparison of growth rates, mouse virulence, antibiotics resistance spectra, and substrate requirements disclosed no differences between the contaminant and a recently isolated clinical strain of P. cepacia. The results indicate that it is critical that pharmaceutical solutions containing benzalkonium chloride as an antimicrobial preservative be formulated without extraneous carbon and nitrogen sources or be preserved with additional antimicrobial agents.
Effects of Combinations of Substrates on Maximum Growth Rates of Several Rumen Bacteria
Authors: Russell James B. , Delfino Frank J. , Baldwin R. L.
Published: January 2020

Five rumen bacteria,
Selenomonas ruminantium, Bacteroides ruminicola, Megasphaera elsdenii, Butyrivibrio fibrisolvens
, and
Streptococcus bovis
were grown in media containing nonlimiting concentrations of glucose, sucrose, maltose, cellobiose, xylose and/or lactate. Each bacterium was grown with every substrate that it could ferment in every possible two-way combination. Only once did a combination of substrates result in a higher maximum growth rate than that observed with either substrate alone. Such stimulations of growth rate would be expected if specific factors unique to individual substrates (transport proteins and/or enzymes) were limiting. Since such synergisms were rare, it was concluded that more general factors limit maximum growth rates in these five bacteria.
Bacteriological survey of sixty health foods
Authors: Andrews W H , Wilson C R , Poelma P L , Romero A , Mislivec P B
Published: January 2020

A bacteriological survey was performed on 1,960 food samples encompassing 60 types of health foods available in the Baltimore-Washington, D.C., metropolitan area. No consistent bacteriological distinction (aerobic plate counts, total coliform and fecal coliform most probable numbers) was observed between foods labeled as organic (raised on soil with compost or nonchemical fertilizer and without application of pesticides, fungicides, and herbicides) and their counterpart food types bearing no such label. Types and numbers of samples containing Salmonella were: sunflower seeds, 4; soy flour, 3; soy protein powder, 2; soy milk powder, 1; dried active yeast, 1; brewers' years, 1; rye flour, 1; brown rice, 1; and alfalfa seeds,1. The occurrence of this pathogen in three types of soybean products should warrant further investigation of soybean derivatives as potentially significant sources of Salmonella.
Phosphate and soil binding: factors limiting bacterial degradation of ionic phosphorus-containing pesticide metabolites
Authors: Daughton C G , Cook A M , Alexander M
Published: January 2020

Soils that had a high binding capacity for inorganic orthophosphate (Pi) had reduced capacities to bind ionic alkyl phosphorus compounds. Only ionic methylphosphonate (MPn) and ionic phenylphosphonate exhibited moderate binding. Pseudomonas testosteroni used either MPn or Pi as a sole phosphorus source and exhibited diauxic utilization of MPn and Pi. The utilization of MPn was suppressed in the presence of Pi. This suppression was abolished by a Pi-binding soil. The soil did not have a significant effect on the maximum rate of degradation of either MPn or the poorly bound ionic O-isopropyl methylphosphonate, whereas the amount of MPn (but not the amount of O-isopropyl methylphosphonate) metabolized was reduced in the presence of soil
Niche in Pasture-Fed Ruminants for the Large Rumen Bacteria
Oscillospira, Lampropedia
, and Quin's and Eadie's Ovals
Authors: Clarke R. T. J.
Published: January 2020

The little-studied large bacteria
Oscillospira, Lampropedia
, and ovals attach rapidly in large numbers to the cuticular surface of clover and grass leaves in the rumen. The cuticle of green leaves may constitute a specific niche for these bacteria.
Mutagenicity of the mycotoxin emodin in the salmonella/microsome system
Authors: Wehner F C , Thiel P G , du Rand M
Published: January 2020

The mycotoxin emodin was found to be a frameshift mutagen for Salmonella typhimurium strain TA 1537 after metabolic activation in a mammalian microsome system.
Survival of bacteria in carcasses
Authors: Gill C O , Penney N
Published: January 2020

Bacteria injected into the bloodstream of guinea pigs shortly before death decreased in number in carcass tissues for about 1 h after death. If initial bacterial numbers were sufficiently low, all bacteria were eliminated, and carcass tissues were sterile 24 h after death. Carcass tissue sterility was maintained with an initial density of Clostridium perfringens or Salmonella typhimurium of 20 cells per g or with an initial density of the other species examined of several hundred cells per gram. With larger numbers of strict and facultative anaerobes, growth commenced after 3 h in carcasses incubated at 30 degrees C. Spores of C. perfringens were killed over the same period as vegetative cells, but growth did not commence until 8 h after death. Bactericidal activity in carcass tissues must therefore be taken into account in evaluating the significance of reports of deep-tissue contamination of carcasses from meat animals.
Effect of inorganic sulfide on the growth and metabolism of Methanosarcina barkeri strain DM
Authors: Mountfort D O , Asher R A
Published: January 2020

Minimal growth of Methanosarcina barkeri strain DM occurred when sulfide was omitted fromthe growth medium, and addition of either sodium sulfate or coenzyme M to sulfide-depleted media failed to restore growth. Optimal growth occurred in the presence of 1.25 mM added sulfide, giving a molar growth yield (YCH4) of 4.4 mg (dry weight) of cells per mmol of CH4 produced. Increasing sulfide to 12.5 mM led to decrease in YCH4 (1.9 mg [dry weight]/mmol of CH4), in the specific growth rate and in be intracellular levels of adenosine triphosphate. However, the specific rate of methane production increased. The data suggested that at elevated sulfide levels (12.5 mM) the decrease in YCH4 might be a result of an increase in the relative energy needed for maintnenace and of uncoupling of growth from energy production.
Production of 3-acetoxyscirpene-4,15-diol from anguidine (4,15-diacetoxyscirpene-3-ol) by Fusarium oxysporum f.sp. vasinfectum
Authors: Claridge C A , Schmitz H
Published: January 2020

Growing cells of Fusarium oxysporum f.sp. vasinfectum (ATCC 7808) formed 3-acetoxyscirpene-4,15-diol from anguidine (4,15-diacetoxyscirpene-3-ol) by way of the intermediates triacetoxyscirpene, 3,4-diacetoxyscirpene-15-ol and 3,15-diacetoxyscirpene-4-ol. The new 3-acetoxy analog was found to be less active than anguidine and the other monoacetoxy derivatives when tested against a series of fungal strains and against HeLa cells in vitro.
Extraction of glucose isomerase from Streptomyces flavogriseus
Authors: Chen W P , Anderson A W , Han Y W
Published: January 2020

Cationic detergent (cetyltrimethylammonium bromide or cetylpyridinium chloride) treatment extracted almost the same amount of glucose isomerase from cells of Streptomyces flavogriseus as mechanical disruption (sonic oscillation or abrasive grinding). The specific activity of the enzyme extracted with cationic detergents was approximately 20% higher than that liberated by mechanical disruption.
High Numbers of Prosthecate Bacteria in Pulp Mill Waste Aeration Lagoons
Authors: Stanley Patricia M. , Ordal Erling J. , Staley James T.
Published: January 2020

Prosthecate bacteria comprised 0.6 to 10.5% of the bacterial community in samples from 11 pulp mill waste aeration lagoons. Because of their distinct morphology, the genera
Ancalomicrobium, Caulobacter, Prosthecobacter, Prosthecomicrobium, Stella
, and
Hyphomicrobium
or
Hyphomonas
could be identified and enumerated by direct microscopic examination. Monthly samples from one lagoon showed that several genera varied from undetectable to predominant among the appendaged organisms. Temperature (season), type of wood pulped, and pulping process did not significantly affect the density of prosthecate bacteria.
Isolation and characterization of a bacteriophage specific for Sphaerotilus natans which contain an unusual base in its deoxyribonucleic acid
Authors: Winston V , Thompson T L
Published: January 2020

A bacteriophage was isolated specific for Sphaerotilus natans, an organism for which bacteriophages have not been previously described. This phage (designated SN1) was found to infect both the single-cell (S-type) and filamentous (R-type) forms of the host, although the sheath appeared to provide R-type cells with a degree of physical protection from infection. SN1 had a hexagonal head and a long flexible tail resembling most closely the phages in Bradley's group B. The nucleic acid was found to be deoxyribonucleic acid and contained an unusual base which substituted for 35% of the guanine. Deoxyribonucleic acid base composition was 56% cytosine plus guanine.
Effect of heat treatment on the performance of tryptose-sulfite-cycloserine agar for enumeration of Clostridium perfringens
Authors: Brodsky M H , Ciebin B W
Published: January 2020

Dissolving dehydrated tryptose-sulfite-cycloserine agar by only boiling or microwaving was found to inhibit Clostridium perfringens colony development in pour plates when compared with C. perfringens recovery in tryptose-sulfite-cycloserine agar prepared by autoclaving.
Preservation of Spores of Vesicular-Arbuscular Endophytes by L-Drying
Authors: Tommerup Inez C. , Kidby Denis K.
Published: January 2020

The spores of four species of vesicular-arbuscular endophytes were L-dried at 22°C, and their viability was tested after heating at 80°C for up to 40 min. L-drying of spores in the soil in which they developed was a very effective method of preservation of all spore types examined. Slow L-drying of spores separated from soil and supported on glass fiber filters also gave high viability for spores of some species. A scheme for the long-term preservation of vesicular-arbuscular endophyte spores is proposed.
Enrichment of cadmium-mediated antibiotic-resistant bacteria in a Douglas-fir (Pseudotsuga menziesii) litter microcosm
Authors: Lighthart B
Published: January 2020

A set of Douglas-fir needle litter microcosms was amended with cadmium, acid, a combination of both, or neither. After 2 weeks of incubation, bacterial colony counts were made of litter homogenates inoculated onto agar media containing an antibiotic (streptomycin, chloromycetin, ampicillin, or gentamicin), cadmium, both, or neither. In all microcosms bacterial abundance was similar but the quality was very dissimiliar. Cadmium-treated microcosms had populations enriched for cadmium and gentamicin resistance and streptomycin and chloramphenicol sensitivity. Acid amendment had no consistent effect on the microcosm populations except that which could be attributed to the cadmium treatment amendment alone.
Evaluation of Microbiological Test Kits for Hydrocarbon Fuel Systems
Authors: Bailey C. A. , May M. E.
Published: January 2020

Commercially available kits were tested for their ability to detect bacterial and fungal contamination in hydrocarbon fuel systems. The handling ease of the kits was evaluated, and their sensitivity was compared with that of conventional methods. Most kits in both laboratory and field studies compared well with laboratory methods and were sufficiently sensitive to determine contamination in shipboard fuel tanks.
Comparative effects of Aroclor 1254 (polychlorinated biphenyls) and phenanthrene on glucose uptake by freshwater microbial populations
Authors: Sayler G S , Lund L C , Shiaris M P , Sherrill T W , Perkins R E
Published: January 2020

The effects of polychlorinated biphenyl (PCB) and phenanthrene stress on glucose uptake by natural microbial populations were examined by the heterotrophic potential technique. Temporal and spatial distributions in glucose uptake velocities were examined for natural samples as well as PCB- and phenanthrene-stressed samples. Statistical analysis indicated significant variability among the various samples. It was demonstrated that the environmental variables contributed significantly to the variability in uptake kinetics. Although general trends indicated a PCB-induced stimulation in uptake velocities, these trends were in part masked by sample variability. Data analysis indicated no statistically significant PCB or phenanthrene effect on either total glucose uptake velocities or the proportion of 14CO2 evolved, as compared to natural unstressed samples.
Microbial cleavage of various organophosphorus insecticides
Authors: Rosenberg A , Alexander M
Published: January 2020

Bacteria able to utilize Aspon, Azodrin, Dasanit, diazinon, malathion, Orthene, parathion, Trithion, dimethoate, Dylox, methyl parathion, and Vapona as sole phosphorus sources were isolated from soil and sewage. Individual isolates used from 3 to 10 of these insecticides as sole phosphorus sources. The extent of growth of two Pseudomonas strains in media containing diazinon and malathion was in the range expected from the amount of insecticide supplied, and their proliferation resulted in disappearance of the chemical. Resting cells of the pseudomonads derived from cultures grown on diazinon or malathion but not orthophosphate caused extensive destruction of these two organophosphates in the presence or absence of chloramphenicol. Extracts of the two bacteria derived from organophosphate-grown cultures catalyzed the disappearance of Aspon, Azodrin, Dasanit, diazinon, malathion, Orthene, parathion, and Trithion but not dimethoate, Dylox, methyl parathion, and Vapona. Results from gas chromatographic analysis suggested that the extracts formed dimethyl phosphate from azodrin, dimethyl phosphorodithioate from malathion, diethyl phosphorodithioate from Trithion, and diethyl phosphorothioate from Dasanit, diazinon, and parathion. Dimethyl phosphate, dimethyl phosphorothioate , dimethyl phosphorodithioate, diethyl phosphate, and diethyl phosphorothioate were not used by the pseudomonads as sole phosphorus sources.
Cyclitol utilization associated with the presence of Klebsielleae in botanical environments
Authors: Talbot H W , Seidler R J
Published: January 2020

Bacteria of the tribe Klebsielleae are capable of metabolizing the cyclitols myoinositol, sequoyitol, and pinitol, which are present in aqueous extracts of redwood. Of the combined Klebsiella isolates from clinical and environmental origins, 100% (138/138), 97% (34/35), and 86% (119/138) fermented inositol, sequoyitol, and pinitol, respectively. These compounds were also used as a sole source of carbon and energy by Klebsiella. Similar results were obtained with Enterobacter isolates, but most other enteric bacteria tested could not metabolize cyclitols. Strains of Klebsiella multiplied to levels exceeding 10(5)/ml in aqueous extracts of nonsterile redwood within 6 days. Most other enteric bacteria did not grow in these extracts. Cyclitol metabolism was found to correlate well with the ability to multiply in redwood extract in the presence of cyclitol-negative indigenous bacteria. The capacity to use cyclitols, which are present in a variety of plant material, might afford Klebsielleae of both environmental and clinical origins an advantage in competing for nutrients and colonizing botanical environments.
Repair detection procedure for enumeration of fecal coliforms and enterococci from seafoods and marine environments
Authors: Hackney C R , Ray B , Speck M L
Published: January 2020

The repair detection procedure of Speck et al. (Appl. Microbiol. 29:549-550, 1975) was adapted for the enumeration of coliforms, fecal coliforms, and enterococci in seafood and environmental samples. Samples were pour plated with Trypticase soy agar, followed by a 1- to 2-h incubation to effect repair; the plates were then overlaid with the selective medium and incubated. Violet red bile agar and an incubation temperature of 45 degrees C were used as the selective conditions for fecal coliforms, and KF streptococcal agar was used for the enumeration of enterococci. The method was more efficient than the standard most-probable-number method for fecal coliform enumeration and also allowed enumeration of the injured cells, which might have remained undetected when selective medium in the most-probable-number method was used. The repair detection method effectively recovered the injured portion of the population of enterococci capable of growing on KF streptococcal agar. The repair enumeration method was not suitable for coliforms in marine samples because associative marine bacteria mimicked coliforms in violet red bile agar plates incubated at 35 degrees C. The marine bacteria did not grow at 45 degrees C and therefore did not interfere with fecal coliform enumeration.
Microbiological transformations of nabilone, a synthetic cannabinoid
Authors: Archer R A , Fukuda D S , Kossoy A D , Abbott B J
Published: January 2020

A screening program was conducted to find microorganisms that modify the synthetic cannabinoid nabilone. After purification, the products from three cultures were analyzed by spectral methods to determine their chemical structures. An optically active 9S-hydroxy-6aR,10aR-trans cannabinoid was isolated from a culture of an unidentified soil bacterium designated A24007. From Bacillus cereus cultures were isolated a 9S,6'-dihydroxy-6aR,10aR-trans cannabinoid, a 9S-hydroxy-6'-keto-6aR,10aR-trans cannabinoid, a 9-keto-6'-hydroxy-6aS,10aS-trans cannabinoid, and a 6',9-diketo-6aS,10aS-trans cannabinoid. All of these products were optically active, as was a 9S-hydroxy-6aS,10AS-trans cannabinoid also isolated from B. cereus cultures. A series of acidic products were isolated from cultures of Nocardia salmonicolor. All of these products contained a carboxylic acid group at the terminal end of three-position alkyl side chains having varying numbers of carbon atoms. Two of the acidic products contained a 9-keto group, whereas all other carboxylic acid products were 9-hydroxy cannabinoids. The array of products obtained from incubation of nabilone indicates the usefulness of microbial transformations in the preparation of new cannabinoids.
Effect of reducing agents on oxidation-reduction potential and the outgrowth of Clostridium botulinum type E spores
Authors: Smith M V , Pierson M D
Published: January 2020

Oxidation-reduction potential (Eh) levels were measured and standardized to pH (Eh7) for Trypticase soy broth containing various concentrations of reducing agents. Prereduced Trypticase soy broth with no added reducing agents exhibited a potential of -141 mV. Ascorbic acid at 0.2 to 0.005% and sodium thioglycolate at concentrations below 0.05% produced an Eh7 higher than the prereduced Trypticase soy broth containing no added reducing agents. The addition of cysteine hydrochloride,2-mercaptoethanol, and sodium formaldehyde sulfoxylate to prereduced Trypticase soy broth resulted in a reduction of Eh7 compared to the system without added reducing agents. The order of relative reducing intensity (from highest to lowest) for the reducing agents when comparing molar concentration was: sodium formaldehyde sulfoxylate,2-mercaptoethanol, cysteine hydrochloride, sodium thioglycolate, and ascorbic acid. Optimal growth of the test organism occurred at low Eh7 and low concentration of the reducing agents. A direct correlation existed between growth of the test organism and -Eh7 x -log concentration of the reducing agent.
Bacteriological Quality of Runoff Water from Pastureland
Authors: Doran J. W. , Linn D. M.
Published: January 2020

Runoff from a cow-calf pasture in eastern Nebraska was monitored for total coliforms (TC), fecal coliforms (FC), and fecal streptococci (FS) during 1976, 1977, and 1978. Bacteriological counts in runoff from both grazed and ungrazed areas generally exceeded recommended water quality standards. The FC group was the best indicator group of the impact of grazing. Rainfall runoff from the grazed area contained 5 to 10 times more FC than runoff from the fenced, ungrazed area. There was little difference in TC counts between the two areas, but FS counts were higher in runoff from the ungrazed area and reflected the contributions from wildlife. Recommended bacteriological water quality standards, developed for point source inputs, may be inappropriate for characterizing nonpoint source pollution from pasture runoff. The FC/FS ratio in pasture runoff was useful in identifying the relative contributions of cattle and wildlife. Ratios below 0.05 were indicative of wildlife sources and ratios above 0.1 were characteristic of grazing cattle. Occasions when the FC/FS ratio of diluted cattle waste exceeded one resulted from differential aftergrowth and die-off between FC and FS. The FC/FS ratio and percentage of
Streptococcus bovis
in pasture runoff are useful indicators for evaluating the effectiveness of livestock management practices for minimizing bacterial contamination of surface water. The importance of choice of medium for the enumeration of FS in runoff derived from cattle wastes is discussed.
Energetics of Microbacterium thermosphactum in glucose-limited continuous culture
Authors: Hitchener B J , Egan A F , Rogers P J
Published: January 2020

Microbacterium thermosphactum was grown at 25 degrees C in glucose-limited continuous culture under aerobic (greater than 120 microM oxygen) and anaerobic (less than 0.2 microM oxygen) conditions. The end products of the anaerobic metabolism of glucose were identified as L-lactate and ethanol. Together these compounds accounted for between 85 and 90% of the glucose utilized over the full range of growth rates studied. In addition, 4% of the glucose utilized was incorporated into cellular material. Under anaerobic conditions the molar growth yield was 40 g (dry weight) of cells per mol of glucose utilized, and the maintenance energy coefficient was 0.4 mmol of glucose utilized per g (dry weight) of cells per h. For cells grown under aerobic conditions in the corresponding values were 73 g/mol and 0.2 mmol/g per h, respectively. The molar growth yield with respect to adenosine 5'-triphosphate varied with the growth rate of the culture, and the true molar growth yield with respect to adenosine 5'-triphosphate was found to be 20 g/mol of adenosine 5'-triphosphate.
L-Glutamine formation by Flavobacterium rigense
Authors: Yamada S , Nabe K , Ujimaru T , Izuo N , Chibata I
Published: January 2020

A penicillin-resistant mutant of Flavobacterium rigense designated as strain 703, FERM-P no. 3628, was obtained after ultraviolet treatment of F. rigense FERM-P no. 3556. The parent strain produces 0-2-hydroxypropylhomoserine from 1,2-propanediol. The mutant was found to be a good producer of L-glutamine. The physiological characteristics of strain 703 were different from the general group of L-glutamic acid-producing bacteria. Strain 703 required L-tryptophan and thiamine but not biotin for its growth. L-Glutamine formation on a specific basis, however, was independent of L-tryptophan and thiamine. Biotin and penicillin were also not effective. Only ammonium fumarate acted as an effective factor on L-glutamine formation. Accumulation of L-glutamine by strain 703 was 10 mg/ml at 30 degrees C for 48 h in a chemically defined medium containing 3% diammonium fumarate.
Sodium nitrite and sorbic acid effects on Clostridium botulinum spore germination and total microbial growth in chicken frankfurter emulsions during temperature abuse
Authors: Sofos J N , Busta F F , Allen C E
Published: January 2020

Samples of (i) a control or of (ii) sodium nitrite-containing or (iii) sorbic acid-containing, mechanically deboned chicken meat frankfurter-type emulsions inoculated with Clostridium botulinum spores, or a combination of ii and iii, were temperature abuse at 27 degrees C. Spore germination and total microbial growth were followed and examined at specified times and until toxic samples were detected. The spores germinated within 3 days in both control and nitrite (20, 40 and 156 micrograms/g) treatments. Sorbic acid (0.2%) alone or in combination with nitrite (20, 40, and 156 micrograms/g) significantly (P less than 0.05) inhibited spore germinations. No significant germination was recorded until toxic samples were detected. A much longer incubation period was necessary for toxin to be formed in nitrite-sorbic acid combination treatments as contrasted with controls or nitrite and sorbic acid used individually. Total growth was not affected by the presence of nitrite, whereas sorbic acid appeared to depress it. Possible mechanisms explaining the effects of nitrite and sorbic acid on spore germination and growth are postulated.
Comparison of the efficacy of steam sterilization indicators
Authors: Lee C H , Montville T J , Sinskey A J
Published: January 2020

Twenty-one commercially available chemical steam sterilization indicators were processed in an empty autoclave for various times at temperatures between 240 and 270 degrees F (ca. 116 and 132 degrees C). The time required to reach a sterilized reading at each temperature was plotted on a semilogarithmic time-temperature plot and compared with the time-temperature sterilization curve for Bacillus stearothermophilus. Five of the indicators had time-temperature kinetics similar to those of B. stearothermophilus, but three of these overestimated the effect of processing. Two of the indicators overestimated the effect of processing and were less sensitive to temperature changes when was B. stearothermophilus. Thirteen of the indicators had time-temperature curves that crossed the B. stearothermophilus plot. One indicator produced such ambiguous results that no determinations could be made with it. Out of 21 indicators tested, only 2 appear to be capable of accurately integrating the time-temperature effect at temperatures between 240 and 270 degrees F. The other indicators should be used only after careful analysis of their suitability for use at a given temperature.
Redox potential-dependent nitrite metabolism by Salmonella typhimurium
Authors: Page G V , Solberg M
Published: January 2020

Salmonellae are generally resistant to the inhibitory effects of NaNO2. Removal of the lipopolysaccharide of Salmonella typhimurium by ethylenediaminetetraacetic acid pretreatment did not result in subsequent inhibtion of growth by NaNO2, indicating that lipopolysaccharide does not function to exclude NaNO2 from the cell. NaNO2 disappeared from the medium while the cells were growing, but, after stationary phase was reached, no further losses were observed unless the pH was maintained above 7.0. Similar losses were observed in a cell-free system if the redox potential of the medium was between -250 and -175 mV. If the disrupted cell suspension was first heated in a boiling water bath for 15 to 18 min, no NaNO2 loss was observed regardless of the redox potential. S. typhimurium is capable of metabolizing NaNO2, possibly by means of a nitrite-reducing enzyme function which is redox controlled.
Cross-Feeding of Lactate Between
Streptococcus lactis
and
Bacteroides
sp. Isolated from Termite Hindguts
Authors: Schultz J. E. , Breznak John A.
Published: January 2020

Streptococcus lactis
and
Bacteroides
sp., isolated from hindguts of
Reticulitermes flavipes
termites, were grown anaerobically in monoculture and coculture. When grown in a glucose medium,
S. lactis
monoculture produced lactate as the major fermentation product, with small amounts of formate, acetate, ethanol, and CO
2
. In coculture, glucose was completely consumed during growth of
S. lactis.
Lactate, produced by
S. lactis
, then supported much of the growth of
Bacteroides
and was fermented to propionate, acetate, and CO
2
. Small amounts of succinate were formed during growth of
Bacteroides
in the coculture, but little change in the formate or ethanol concentration was observed. Monoculture growth of
Bacteroides
in a tryptone-yeast extract medium revealed that incorporation of 20 to 40 mM lactate increased cell yields and production of organic acids. However, initial lactate concentrations greater than 40 mM suppressed not only growth of
Bacteroides
but also acidic product formation. Results suggest that cross-feeding of lactate between streptococci and bacteroides constitutes one aspect of the overall hindgut fermentation in termites.
The Rumen Ciliate
Epidinium
in Primary Degradation of Plant Tissues
Authors: Bauchop T.
Published: January 2020

Pieces of lucerne stem suspended in a sheep rumen in nylon bags were removed after different time intervals and examined by scanning electron microscopy. By 15 min large numbers of the ciliate protozoan
Epidinium
Crawley were attached to damaged areas of the stem, although a complex protozoal fauna was present in the rumen contents. Highest concentrations were on cortex and phloem tissues, with densely packed protozoa forming a complete ring around the transversely cut end of the stem between the epidermis and the vascular cylinder. Within 2 h there was extensive degradation of thin-walled tissues, as indicated by the amount of exposed vascular cylinder. Epidermis was not degraded but slid down the side of the stem as the underlying tissues were removed. This rapid degradation of plant tissue is explained by direct ingestion of tissues by the protozoa on the plant fragments. Many of the epidinia attached to the stem pieces were ingesting phloem elements and chlorophyllous tissue. The rumen protozoa have not previously been shown to participate on this scale in the physical degradation of plant material.
Isolation of Legionella pneumophila from nonepidemic-related aquatic habitats
Authors: Fliermans C B , Cherry W B , Orrison L H , Thacker L
Published: January 2020

Continuous centrifugation of large volumes of water from natural southeastern lakes allowed quantitative detection of Legionella pneumophila by direct immunofluorescent staining. Positive samples were injected intraperitoneally into guinea pigs, and the L. pneumophila were isolated and identified by their morphological, cultural, physiological, and serological characteristics.