bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of a fluoro substituent on the fungal metabolism of 1-fluoronaphthalene
Authors: Cerniglia C E , Miller D W , Yang S K , Freeman J P
Published: January 2020

The metabolism of 1-fluoronaphthalene by Cunninghamella elegans ATCC 36112 was studied. The metabolites were isolated by reverse-phase high-pressure liquid chromatography and characterized by the application of UV absorption, 1H nuclear magnetic resonance, and mass spectral techniques. C. elegans oxidized 1-fluoronaphthalene predominantly at the 3,4- and 5,6-positions to form trans-3,4-dihydroxy-3,4-dihydro-1-fluoronaphthalene and trans-5,6-dihydroxy-5,6-dihydro-1-fluoronaphthalene. In addition, 1-fluoro-8-hydroxy-5-tetralone, 5-hydroxy-1-fluoronaphthalene, and 4-hydroxy-1-fluoronaphthalene as well as glucoside, sulfate, and glucuronic acid conjugates of these phenols were formed. Circular dichroism spectra of the trans-3,4- and trans-5,6-dihydrodiols formed from 1-fluoronaphthalene indicated that the major enantiomers of the dihydrodiols have S,S absolute stereochemistries. In contrast, the trans-5,6-dihydrodiol formed from 1-fluoronaphthalene from 3-methylcholanthrene-treated rats had Cotton effects that are opposite in sign (R,R) to those formed by C. elegans. The results indicate that the fungal monooxygenase-epoxide hydrolase systems are highly stereoselective in the metabolism of 1-fluoronaphthalene and that a fluoro substituent blocks epoxidation at the fluoro-substituted double bond, decreases oxidation at the aromatic double bond that is peri to the fluoro substituent, and enhances metabolism at the 3,4- and 5,6-positions of 1-fluoronaphthalene.
Growth Potential of Halophilic Bacteria Isolated from Solar Salt Environments: Carbon Sources and Salt Requirements
Authors: Javor Barbara J.
Published: January 2020

Eighteen strains of extremely halophilic bacteria and three strains of moderately halophilic bacteria were isolated from four different solar salt environments. Growth tests on carbohydrates, low-molecular-weight carboxylic acids, and complex medium demonstrated that the moderate halophiles and strains of the extreme halophiles
Haloarcula
and
Halococcus
grew on most of the substrates tested. Among the
Halobacterium
isolates were several metabolic groups: strains that grew on a broad range of substrates and strains that were essentially confined to either amino acid (peptone) or carbohydrate oxidation. One strain (WS-4) only grew well on pyruvate and acetate. Most strains of extreme halophiles grew by anaerobic fermentation and possibly by nitrate reduction. Tests of growth potential in natural saltern brines demonstrated that none of the halobacteria grew well in brines which harbor the densest populations of these bacteria in solar salterns. All grew best in brines which were unsaturated with NaCl. The high concentrations of Na
+
and Mg
2+
found in saltern crystallizer brines limited bacterial growth, but the concentrations of K
+
found in these brines had little effect. MgSO
4
was relatively more inhibitory to the extreme halophiles than was MgCl
2
, but the reverse was true for the moderate halophiles.
Identification of swainsonine as a probable contributory mycotoxin in moldy forage mycotoxicoses
Authors: Broquist H P , Mason P S , Hagler W M , Harris T M
Published: January 2020

When infested with the fungus Rhizoctonia leguminicola, certain forages, e.g., red clover hay, can cause a "slobber syndrome" of varying severity when consumed by ruminants. The causative agent has been presumed to be slaframine [(1S,6S,8aS)-1-acetoxy-6-aminooctahydroindolizine], which is produced by R. leguminicola. In one serious outbreak of the slobber syndrome in horses, the red clover forage involved was carefully examined and found to contain R. leguminicola and slaframine. An identical hay sample is shown here by ion-exchange chromatographic and gas chromatographic-mass spectrometric analysis of appropriate hay extracts to also contain swainsonine [(1S,2R,8R,8aR)-1,2,8-trihydroxyoctahydroindolizine], a potent alpha-mannosidase inhibitor. Swainsonine has previously been isolated from pure cultures of R. leguminicola and from higher plants, namely the Darling pea (Swainsona canescens) and spotted locoweed (Astragalus lentiginosus). Consumption of Darling pea and spotted locoweed by livestock results in a severe neurological condition resembling that observed in hereditary mannosidosis in cattle and humans. Our findings indicate that swainsonine may be viewed as a mycotoxin when present in moldy forages consumed by livestock. The extent to which slaframine and swainsonine mycotoxicosis pose threats to animal husbandry and, indeed, to humans, if these alkaloids were to enter the human food chain, deserves serious consideration.
Different Temperature Optima for Methane Formation When Enrichments from Acid Peat Are Supplemented with Acetate or Hydrogen
Authors: Svensson Bo H.
Published: January 2020

Laboratory studies of methane formation in peat samples from an acid subarctic mire in Sweden indicated the presence of a low-temperature-adapted methanogenic flora. Enrichment culture studies with ethanol, acetate, hydrogen, or a combination of these as substrate for methane formation provided evidence for the existence of two different methanogenic populations in the peat: one, unaffected by hydrogen and using acetate, with a temperature optimum at 20°C; the other, oxidizing hydrogen, with a temperature optimum at ca. 28°C.
Simple field method for concentration of viruses from large volumes of water
Authors: Toranzos G A , Gerba C P , Hanssen H
Published: January 2020

A pressure spray tank was adapted to supply positive pressure for processing water samples for concentrating viruses with microporous filters under field conditions. This low-cost system allows water to be processed in locations where electric current is not readily available or where light-weight portable equipment is required.
Isolation from haddock tissue of psychrophilic bacteria with maximum growth temperature below 20 degrees C
Authors: Makarios-Laham I , Levin R E
Published: January 2020

A series of seven gram-negative obligately psychrophilic cultures were isolated from a fresh haddock fillet and constituted 8.8% of the total bacterial population on the tissue. All of these isolates are facultatively anaerobic, ferment dextrose without gas production, produce trimethylamine, are sensitive to the vibriostatic agent 0/129, and grow at temperatures from 0 to 15 degrees C but not at 20 degrees C.
Cellulase and Sugar Formation by
Bacteroides cellulosolvens
, a Newly Isolated Cellulolytic Anaerobe
Authors: Giuliano Christine , Khan A. W.
Published: January 2020

A newly isolated mesophilic anaerobe,
Bacteroides cellulosolvens
, has the ability to produce cellulase and to degrade cellulose to cellobiose and glucose. It does not utilize glucose, and it lacks β-glucosidase activity. This anaerobe appears to degrade cellulose to cellobiose by cellulase action, and the presence of cells appears necessary for the formation of glucose.
2-Chloro-4-amino-1,3,5-triazine-6(5H)-one: a new intermediate in the biodegradation of chlorinated s-triazines
Authors: Grossenbacher H , Horn C , Cook A M , Hütter R
Published: January 2020

Pseudomonas sp. strain A grew with 2-chloro-1,3,5-triazine-4,6-diamine as the sole and growth-limiting source of nitrogen. The substrate was utilized quantitatively and concomitantly with growth and with excretion of a product which was identified as 2-chloro-4-amino-1,3,5-triazine-6(5H)-one. The reaction yielded 1 mol of organic product and 1 mol of NH4+ per mol of substrate.
Heat injury and repair in Campylobacter jejuni
Authors: Palumbo S A
Published: January 2020

A procedure for detecting and quantitating heat injury in Campylobacter jejuni was developed. Washed cells of C. jejuni A7455 were heated in potassium phosphate buffer (0.1 M, pH 7.3) at 46 degrees C. Samples were plated on brucella agar supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate and on a medium containing brilliant green, bile, Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate. Colonies were counted after 5 days of incubation at 37 degrees C in an atmosphere containing 5% O2, 10% CO2, and 85% N2. After 45 min at 46 degrees C, there was virtually no killing and ca. two log cycles of injury. Cells grown at 42 degrees C were more susceptible to injury than cells grown at 37 degrees C. The addition to brucella agar supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate of three different antibiotic mixtures used in the isolation of C. jejuni from foods or clinical specimens did not prevent recovery of heat-injured C. jejuni. Cells lost 260 nm of absorbing materials during heat injury. The addition of 5% NaCl or 40% sucrose to the heating buffer prevented leakage but did not prevent injury. Of the additional salts, sugars, and amino acids tested for protection, only NH4Cl, KCl, and LiCl2 prevented injury. Heat-injured C. jejuni repaired (regained dye and bile tolerance) in brucella broth supplemented with Na2S2O3, FeSO4 X 7H2O, and sodium pyruvate within 4 h. Increasing the NaCl in this medium to 1.25% inhibited repair, and increasing it to 2% was lethal. Heat-injured C. jejuni will repair at 42 degrees C but not at 5 degrees C.
Genetic Adaptation to Elevated Carbon Dioxide Atmospheres by
Pseudomonas
-Like Bacteria Isolated from Rock Cod (
Sebastes
spp.)
Authors: Johnson Andrew R. , Ogrydziak David M.
Published: January 2020

The microorganisms on rock cod fillets stored in a modified atmosphere (MA; 80% CO
2
-20% air) at 4°C for 21 days were isolated. Only
Lactobacillus
sp. (71 to 87%) and tan-colored
Pseudomonas
sp.-like isolates (TAN isolates) were found. The TAN isolates grew more slowly in MA than in air at 8°C. When TAN isolates were grown in air at 8°C and then transferred to MA at 8°C, there was an initial decline in viable counts for 10 to 30 h followed by exponential growth. During this exponential growth phase in MA, the growth rates of the TAN isolates from MA-stored fish were significantly greater than those of the TAN isolates from fresh fish. When a TAN isolate from fresh fish was grown under MA for 21 days, it then grew as rapidly under MA as isolates from MA-stored fish. These results suggest that the TAN isolates genetically adapt to high levels of CO
2
.
Mechanisms and pathways of aniline elimination from aquatic environments
Authors: Lyons C D , Katz S , Bartha R
Published: January 2020

The fate of aniline, a representative of arylamine pollutants derived from the manufacture of dyes, coal liquefaction, and pesticide degradation, was comprehensively evaluated by use of unpolluted and polluted pond water as model environments. Evaporation plus autoxidation proved to be minor elimination mechanisms, removing ca. 1% of the added aniline per day. Instantaneous binding to humic components of a 0.1% sewage sludge inoculum removed 4%. Biodegradation of aniline in pond water was accelerated by the sewage sludge inoculum. A substantial portion of the degraded aniline carbon was mineralized to CO2 within a 1-week period, and microbial biomass was formed as a result of aniline utilization. Biodegradation was clearly the most significant removal mechanism of polluting aniline from pond water. A gas chromatographic-mass spectrometric analysis of biodegradation intermediates revealed that the major pathway of aniline biodegradation in pond water involved oxidative deamination to catechol, which was further metabolized through cis,cis-muconic, beta-ketoadipic, levulinic, and succinic acid intermediates to CO2. Minor biodegradation pathways involved reversible acylation to acetanilide and formanilide, whereas N-oxidation resulted in small amounts of oligomeric condensation products.
Effect of pH, application technique, and chlorine-to-nitrogen ratio on disinfectant activity of inorganic chloramines with pure culture bacteria
Authors: Ward N R , Wolfe R L , Olson B H
Published: January 2020

The influence of pH, application technique, and chlorine-to-nitrogen weight ratio on the bactericidal activity of inorganic chloramine compounds was determined with stock and environmental strains of Escherichia coli, Salmonella spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacter cloacae. The rate of inactivation increased from 1.5 to 2 times as the chlorine-to-nitrogen weight ratio was adjusted from 2:1 to 5:1, 5 to 6 times as the pH was decreased from 8 to 6, and 5 to 6 times as the concentration was increased from 1 to 5 mg/liter. Separate additions of free chlorine and ammonia (concurrent addition and preammoniation) into seeded water at or below pH 7.5 resulted in killing comparable to that observed with free chlorine (99% inactivation in less than 20 s). At pH 8, inactivation by separate additions was considerably slower and was comparable to that by prereacted chloramine compounds (99% inactivation in 25 to 26 min). Determination of the effectiveness of inorganic chloramine compounds as primary disinfectants for drinking water must consider the method of application, pH and concentrations of chlorine and ammonia.
Antagonism by gram-negative bacteria to growth of Yersinia enterocolitica in mixed cultures
Authors: Schiemann D A , Olson S A
Published: January 2020

The inhibition of the growth of Yersinia enterocolitica by other gram-negative bacteria in mixed cultures at 32 degrees C was not the consequence of a depletion in essential nutrients, an unfavorable change in pH or oxygen tension or the production of toxic metabolic products. The inability of Y. enterocolitica to attain its potential maximum population in mixed cultures appeared instead to result from "metabolic crowding," which occurred when the faster-growing antagonistic organism reached stationary-phase density. Lowering the incubation temperature, a technique commonly used in "cold" enrichment for isolation of Y. enterocolitica, tended to equalize growth rates and thereby allowed Y. enterocolitica to achieve a higher population.
Formation of
n
-Butanol from
d
-Glucose by Strains of the “
Clostridium tetanomorphum
” Group
Authors: Gottwald Matthias , Hippe Hans , Gottschalk Gerhard
Published: January 2020

A clostridial strain has been isolated that produced
n
-butanol, ethanol, butyrate, and acetate as major fermentation products from glucose but no acetone. At a pH of 6.6,
n
-butanol was formed by this microorganism only during growth. On the basis of its physiological characteristics and DNA-DNA homology data, the strain was assigned to the “
Clostridium tetanomorphum
” group (S. Nakamura, I. Okado, T. Abe, and S. Nishida, J. Gen. Microbiol. 113:29-35, 1979). All members of this group were shown to produce
n
-butanol from glucose as the major fermentation product, whereas
C. cochlearium
produced it in only minor amounts.
Effects of Abiotic Factors on Acetylene Reduction by Cyanobacteria Epiphytic on Moss at a Subantarctic Island
Authors: Smith Valdon R.
Published: January 2020

Acetylene reduction (AR) rates by cyanobacteria epiphytic on a moss at Marion Island (46°54′ S, 37°45′ E) increased from −5°C to a maximum at 25 to 27°C.
Q
10
values between 0 and 25°C were between 2.3 and 2.9, depending on photosynthetic photon flux density. AR rates declined sharply at temperatures above the optimum and were lower at 35°C than at 0°C. Photosynthetic photon flux density at low levels markedly influenced AR, and half of the maximum rate occurred at 84 μmol m
−2
s
−1
, saturation occurring at ca. 1,000 μmol m
−2
s
−1
. Higher photosynthetic photon flux density levels decreased AR rates. AR increased up to the highest sample moisture content investigated (3,405%), and the pH optimum was between 5.9 and 6.2. The addition of P, Co, and Mo, individually or together, depressed AR.
Escherichia coli variants for gas and indole production at elevated incubation temperatures
Authors: Bueschkens D H , Stiles M E
Published: January 2020

Two strains of Escherichia coli were subjected to heat and cold-storage treatments to determine the stability of the fecal E. coli characteristics of gas production from lactose and indole production at elevated incubation temperatures. No variants were detected with repeated sublethal heat treatment. A high incidence of variants was observed with extended cold storage of the organisms in liquid and semisolid media, especially with poor nutrient composition, and in the absence of cryoprotective agents. The indole characteristic at elevated temperature was more stable than the production of gas from lactose. The critical temperature at which both gas production from lactose and the indole characteristic were lost was 44.5 degrees C. It appeared that the variants resulted from increased temperature sensitivity of the formic hydrogen lyase and tryptophanase enzymes, respectively.
Superoxide dismutase in ruminal bacteria
Authors: Fulghum R S , Worthington J M
Published: January 2020

Of 13 species of anaerobic ruminal bacteria examined, 11 were found to contain measurable levels of superoxide dismutase activity. Four of five other strict anaerobic species studied for comparison were found to contain superoxide dismutase activity.
Production of Viscous Dextran-Containing Whey-Sucrose Broths by
Leuconostoc mesenteroides
ATCC 14935
Authors: Schwartz Robert D. , Bodie Elizabeth A.
Published: January 2020

Viscous broths were produced by growing
Leuconostoc mesenteroides
on a medium containing whey supplemented with sucrose. When combined with similarly produced xanthan-containing broths, a synergistic increase in viscosity was observed.
Immobilization by Polyurethane of
Pseudomonas dacunhae
Cells Containing
l
-Aspartate β-Decarboxylase Activity and Application to
l
-Alanine Production
Authors: Fusee Murray C. , Weber Jennifer E.
Published: January 2020

Whole cells of
Pseudomonas dacunhae
containing
l
-aspartate β-decarboxylase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol; W. R. Grace & Co., Lexington, Mass.). The immobilized cell preparation was used to convert
l
-aspartic acid to
l
-alanine. Properties of the immobilized
P. dacunhae
cells containing aspartate β-decarboxylase activity were investigated with batch reactors. Retention of enzyme activity was observed to be as much as 100% when cell lysis was allowed to occur before immobilization. The pH and temperature optima were determined to be 5.5 and 45°C, respectively. Immobilized
P. dacunhae
l
-aspartate β-decarboxylase activity was stabilized by the addition of 0.1 mM pyridoxal-5-phosphate and 0.1 mM α-ketoglutaric acid to a 1.7 M ammonium aspartate (pH 5.5) substrate solution. Under conditions of semicontinuous use in a batch reactor, a 2.5% loss in immobilized
l
-aspartate β-decarboxylase activity was observed over a 31-day period.
Nitrogen Fixation in an Establishing Alfalfa (
Medicago sativa
L.) Ley in Sweden, Estimated by Three Different Methods
Authors: Mårtensson Anna M. , Ljunggren Hans D.
Published: January 2020

In an investigation of the ability of alfalfa to fix nitrogen under field conditions in Scandinavia, N
2
fixation during the establishment year ranged between 7.85 and 10.37 g of N m
−2
, depending on the method used. The methods used were an in situ acetylene reduction method, a
15
N isotope dilution method using two reference crops, and a total-N difference method. The dynamics of nitrogenase activity in relation to plant development was studied by using the acetylene reduction method. Also, the diurnal variation in N
2
fixation at the field site was studied with the acetylene reduction method; no diurnal change was detected, which is explained by the fact that the nodules within the soil were protected against short-term fluctuations in temperature. The significant amount of nitrogen fixed by alfalfa during its first year even at northern latitudes suggests that this crop offers an alternative to conventional field management of heavily fertilized nonlegume leys.
Metabolism of Trimethylamine, Choline, and Glycine Betaine by Sulfate-Reducing and Methanogenic Bacteria in Marine Sediments
Authors: King Gary M.
Published: January 2020

The response of methanogenesis and sulfate reduction to trimethylamine, choline, and glycine betaine was examined in surface sediments from the intertidal region of Lowes Cove, Maine. Addition of these substrates markedly stimulated methanogenesis in the presence of active sulfate reduction, whereas addition of other substrates, including glucose, acetate, and glycine, had no effect on methane production. Sulfate reduction was stimulated simultaneously with methanogenesis by the various quaternary amines and all other substrates examined. Incubation of exogenous trimethylamine, choline, or glycine betaine with either bromoethane sulfonic acid or sodium molybdate was used to establish pathways of degradation of the substrates. Methanogenesis dominated the metabolism of trimethylamine, although limited nonmethanogenic activity, perhaps by sulfate-reducing bacteria, was observed. Acetate was oxidized primarily by sulfate reducers. Both choline and glycine betaine were fermented stoichiometrically to acetate and trimethylamine; apparently, neither substrate could be utilized directly by methanogens or sulfate reducers, and the activities of fermenters, methanogens, and sulfate reducers were all required to effect complete mineralization. These observations support the hypothesis that the presence of quaternary amines can mediate the coexistence of sulfate reduction and methanogenesis in marine surface sediments; they also implicate methanogens in the nitrogen cycle of marine sediments containing quaternary amines.
Construction of plasmid cloning vectors for lactic streptococci which also replicate in Bacillus subtilis and Escherichia coli
Authors: Kok J , van der Vossen J M , Venema G
Published: January 2020

The cryptic Streptococcus cremoris Wg2 plasmid pWV01 (1.5 megadaltons) was genetically marked with the chloramphenicol resistance (Cmr) gene from pC194. The recombinant plasmid (pGK1, 2.4 megadaltons) replicated and expressed Cmr in Bacillus subtilis. From this plasmid an insertion-inactivation vector was constructed by inserting the erythromycin resistance (Emr) gene from pE194 cop-6. This plasmid (pGK12, 2.9 megadaltons) contained a unique BclI site in the Emr gene and unique ClaI and HpaII sites outside both resistance genes. It was stably maintained in B. subtilis at a copy number of approximately 5. pGK12 also transformed Escherichia coli competent cells to Cmr and Emr. The copy number in E. coli was about 60. Moreover, pGK12 transformed protoplasts of Streptococcus lactis. In this host both resistance genes are expressed. pGK12 is stably maintained in S. lactis at a copy number of 3.
Selective medium for Pseudomonas cepacia containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate
Authors: Wu B J , Thompson S T
Published: January 2020

Contamination of solutions and lotions with Pseudomonas cepacia is a growing concern among health professionals. The identification of P. cepacia usually requires a long series of biochemical tests. In an effort to develop a more direct method, we evaluated plate count agar containing 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate at respective concentrations of 1 and 75 micrograms/ml as a medium for selectively isolating P. cepacia. The medium inhibited the growth of all gram-negative bacilli and gram-positive cocci tested except P. cepacia and Serratia marcescens. These two microorganisms could easily be differentiated by their colony morphology and their reactions in the oxidase test. When nonsterilized water samples were inoculated with P. cepacia and spread or streaked on the selective medium, all P. cepacia organisms were recovered. These results demonstrate the usefulness of 9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan and polymyxin B sulfate in the detection of P. cepacia. We believe that this selective medium could be useful in isolating P. cepacia from mixed bacterial flora that might be present in environmental water and water-related samples, such as solutions and lotions.
Bacterial dry matter content and biomass estimations
Authors: Bratbak G , Dundas I
Published: January 2020

Approximately 20% dry-matter content appears to be an accepted standard value for bacterial cells. We have found that the dry-matter content of bacteria may be more than twice as high as generally assumed. The main reason for the low estimates seems to be that proper corrections for intercellular water have not been made when estimating the wet weight of the cells. Using three different bacterial strains, we determined a dry-matter content of cells ranging from 31 to 57%, suggesting not only that the accepted standard value is much too low but also that it is far from standard. To convert bacterial biovolume into biomass (carbon content), we suggest that 0.22 g of C cm-3 should be used as a conversion factor.
Production and characterization of antibody against diacetoxyscirpenol
Authors: Chu F S , Liang M Y , Zhang G S
Published: January 2020

Antibodies against diacetoxyscirpenol (DAS) were obtained from rabbits after immunizing them with hemisuccinate or hemiglutarate derivatives of DAS conjugated to bovine serum albumin (BSA). DAS-hemiglutarate-BSA was found to be a much better immunogen than DAS-hemisuccinate-BSA. Competitive radioimmunoassay revealed that the antisera obtained from rabbits after immunization with DAS-hemiglutarate-BSA showed high specificity toward DAS. The concentrations causing 50% displacement of radioactive DAS by unlabeled DAS, 4-monoacetoxyscirpenol (MAS), and 15-MAS were found to be 1.5, 130, and 300 ng per assay, respectively. Thus, the cross-reactivities for 4-MAS and 15-MAS are ca. 87 and 300 times weaker than that of DAS. Practically no cross-reaction (less than 5% displacement) was observed when deoxynivalenol, T-2 toxin, deoxyverrucarol, and scirpentriol were tested at a concentration of 2,000 ng/ml.
Use of a computer to group actinomycetes for studies on the ecology of soil microorganisms
Authors: Keast D , Rowe P , Sanfelieu L , Shannahan J , Bowra B , Skates S , Stapley E O , Woodruff H B
Published: January 2020

A computer program has been prepared for grouping soil actinomycetes into cluster groups based on the presence or absence of aerial mycelium, the color of soluble pigment, and the shade of color of surface and reverse mycelium. The program automatically condenses cultures with wide ranges of characteristics into a limited number of groups and provides a permanent record so that comparisons can be made among experiments performed over a span of time. The program permits the grouping of large numbers of cultures with minimal laboratory effort and has proven useful in defining some of the ecological factors that lead to changed actinomycete populations in soils.
Morphological and genetic effects of benomyl on polyploid brewing yeasts: isolation of auxotrophic mutants
Authors: Bilinski C A , Sills A M , Stewart G G
Published: January 2020

An enrichment procedure after ethyl methanesulfonate mutagenesis and exposure to the fungicide benomyl yielded mutants auxotrophic for several amino acids from two polyploid Saccharomyces spp. Benomyl treatment was found to have a marked morphological effect on polyploid Saccharomyces cerevisiae, causing cells to adopt a characteristic doublet cell morphology in which buds are nearly as large as the parent cells. Experiments in which nuclear division was monitored in benomyl-induced doublet cells by Giemsa nuclear staining demonstrated an unusual sequence of cytological events which culminated in the formation of binucleate parental and mononucleate bud components. The frequency of formation of doublet and binucleate parent cells was found to depend on the strain employed and the benomyl concentration administered.
Production of Nivalenol and Fusarenone-X by
Fusarium tricinctum
Fn-2B on a Rice Substrate
Authors: Lee Yin-Won , Mirocha C. J.
Published: January 2020

Fusarium tricinctum
Fn-2B was grown on a rice substrate at room temperature (22 to 26°C) for 2 weeks followed by growth at a low temperature (10 to 12°C) for an additional 2 weeks. A total of 1.5 g of nivalenol and 80 mg of fusarenone-X were obtained from 2 kg of rice culture. The methods of production, extraction, and purification are described.
Propionate Exchange Reactions in Methanogenic Ecosystems
Authors: Boone David R.
Published: January 2020

Propionate degradation was measured with [1-
14
C]- and [2-
14
C]propionate in an anaerobic digestor. When [1-
14
C]propionate was used, label disappeared more rapidly from the propionate pool than when [2-
14
C]propionate was used. This indicated that an exchange reaction involving the carboxyl group of propionate occurred. Labeled propionate added to digestor samples which were equilibrated with H
2
lost label from the carboxyl group but not from the methylene group.
Distribution of Brown Blotch Bacteria in Wild and Cultivated Species of
Basidiomycetes
Authors: Bessette Alan E.
Published: January 2020

Wild and cultivated
Basidiomycetes
species were cultured to determine the distribution of bacteria causing brown blotch disease of
Agaricus bisporus
. Colonies from each basidiocarp were screened for brown blotch organisms by the white line and host pathogenicity tests. Isolates causing brown blotch were identified as
Pseudomonas tolaasi
and an
Arthrobacter
species.
Decline in Deoxynivalenol (Vomitoxin) Concentrations in 1983 Ontario Winter Wheat Before Harvest
Authors: Scott Peter M. , Nelson Kit , Kanhere Shriniwas R. , Karpinski Kazimierz F. , Hayward Stephen , Neish Gordon A. , Teich Abe H.
Published: January 2020

Samples of winter wheat were collected in 1983 from five fields in southwestern Ontario that were naturally infected with head blight. The geometric mean concentration of deoxynivalenol (vomitoxin) in the grain declined significantly from 1.56 μg/g on 7 July to 0.21 μg/g on 14 July and 0.11 μg/g on 18 July and did not increase at harvest (20 through 27 July).
Detection of aflatoxin D1 in ammoniated corn by mass spectrometry-mass spectrometry
Authors: Grove M D , Plattner R D , Peterson R E
Published: January 2020

Corn cultured with Aspergillus flavus to produce a high level of aflatoxin was ammoniated at 37 degrees C for 21 days. An extract of the ammoniated corn was separated by thin-layer chromatography, followed by reversed-phase high-pressure liquid chromatography. Examination of the fractions by tandem mass spectrometry led to detection of aflatoxin D1 as a product of the corn ammoniation process.
Intracellular glycosidases of human colon Bacteroides ovatus B4-11
Authors: Reddy N R , Palmer J K , Pierson M D , Bothast R J
Published: January 2020

Activity of various glycosidases in the intracellular enzyme fraction of Bacteroides ovatus B4-11 was investigated. During 120 h of incubation at 37 degrees C, ca. 30% of the crude hemicellulose was hydrolyzed by an intracellular enzyme fraction of strain B4-11. Xylose was the major sugar released from crude hemicellulose. Glycosidases (alpha-1,6-glucosidase, alpha-1,4-glucosidase, beta-1,4-glucosidase, and beta-1,4-xylosidase) were induced in B. ovatus B4-11 by crude hemicellulose and heteroxylan. When B. ovatus B4-11 was grown on either crude hemicellulose or heteroxylan, the predominant enzyme in the intracellular enzyme fraction was beta-1,4-xylosidase.
Plasmid associated with diplococcin production in Streptococcus
Authors: Davey G P
Published: January 2020

The ability to produce diplococcin (Dip+) was transferred by conjugation from Streptococcus cremoris 346 to two plasmid-free S. cremoris recipients at a high frequency (10(-1) per donor). Dip+ transconjugants from each mating gained a 54-megadalton plasmid. Spontaneous loss of this plasmid restored the Dip- phenotype.
Evidence for a Terpene-Based Food Chain in the Gulf of Alaska
Authors: Button D. K.
Published: January 2020

A mixture of
14
C-terpenes was prepared from conifer seedlings and introduced into fresh seawater samples taken near Seward, Alaska. Initial rates of oxidation by the indigenous bacteria were linear and faster than the rates of toluene oxidation. Turnover times were 4 to 19 days. Autoradiographic measurements with
3
H-terpenes indicated that at least 10% of the 0.6 � 10
9
to 2.7 � 10
9
bacteria per liter present could catabolize terpenes. The rate of terpene oxidation, 24 μg of terpenes per g of cells per h with 3 μg of terpenes added per liter, was a constant function of bacterial biomass. The specific affinity of the process was estimated to be between 8.1 and 81 liters/g of cells per h, indicating a high state of induction and the probable presence of terpenes. Terpene-oxidizing bacteria were grown on [
14
C]alanine and added to fresh seawater samples. Transfer of the bacterial radioactivity into larger particles at a rate of 146 pg/liter per h from the 2.3 � 10
9
organisms added indicated that any terpenes present would participate in the food chain.
Degradation of 4-Chlorobenzoic Acid by
Arthrobacter
sp
Authors: Marks Trevor S. , Smith Anthony R. W. , Quirk Alan V.
Published: January 2020

A mixed population, enriched and established in a defined medium, from a sewage sludge inoculum was capable of complete mineralization of 4-chlorobenzoate. An organism, identified as
Arthrobacter
sp., was isolated from the consortium and shown to be capable of utilizing 4-chlorobenzoate as the sole carbon and energy source in pure culture. This organism (strain TM-1), dehalogenated 4-chlorobenzoate as the initial step in the degradative pathway. The product, 4-hydroxybenzoate, was further metabolized via protocatechuate. The ability of strain TM-1 to degrade 4-chlorobenzoate in liquid medium at 25�C was improved by the use of continuous culture and repeated sequential subculturing. Other chlorinated benzoates and the parent compound benzoate did not support growth of strain TM-1. An active cell extract was prepared and shown to dehalogenate 4-chloro-, 4-fluoro-, and 4-bromobenzoate. Dehalogenase activity had an optimum pH of 6.8 and an optimum temperature of 20�C and was inhibited by dissolved oxygen and stimulated by manganese (Mn
2+
). Strain improvement resulted in an increase in the specific activity of the cell extract from 0.09 to 0.85 nmol of 4-hydroxybenzoate per min per mg of protein and a decrease in the doubling time of the organism from 50 to 1.6 h.
Inhibition of growth and patulin synthesis in Penicillium expansum by potassium sorbate and sodium propionate in culture
Authors: Lennox J E , McElroy L J
Published: January 2020

Potassium sorbate and sodium propionate brought about a marked inhibition in the growth of Penicillium expansum and a proportionally greater inhibition in the synthesis of patulin by the mold. At inhibitor concentrations used commercially in bakery products, propionate inhibited growth less efficiently than sorbate did but was a more effective inhibitor of patulin synthesis.
Microbial removal of wastewater organic compounds as a function of input concentration in soil columns
Authors: Hutchins S R , Tomson M B , Wilson J T , Ward C H
Published: January 2020

The fate of six organic compounds during rapid infiltration of primary wastewater through soil columns was studied. Feed solutions were prepared which contained all six compounds in individual concentrations ranging from 1 to 1,000 micrograms/liter and were applied to separate soil columns on a flooding-drying schedule. Feed solutions and column effluents were analyzed for the compounds by XAD resin (Rohm and Haas Co.) extraction and gas chromatography-mass spectrometry during each of three successive inundation cycles. Breakthrough profiles of o-phenylphenol were relatively consistent during the test, with fractional breakthrough (mass output/mass input) being independent of input concentration. Consistent profiles were also observed for 2-(methylthio)benzothiazole, although fractional breakthroughs were higher at lower input concentrations, indicating that removal processes were operating less efficiently at these levels. The behavior of p-dichlorobenzene was similar to that of 2-(methylthio)benzothiazole after the first inundation cycle, with the exception that increased fractional breakthroughs were observed at the highest input concentration as well. Microbial adaptation was evident for benzophenone, 2-methylnaphthalene, and p-(1,1,3,3-tetramethylbutyl)phenol, as indicated by increased removal efficiencies during successive inundation cycles, especially at the higher input concentrations. Column effluent concentrations of the latter two compounds were independent of input concentrations during the final stage of the test. Microbial activity and adaptation were confirmed for several of the compounds by using isotopes and measuring the extent of mineralization in batch tests with soil from one of the columns.(ABSTRACT TRUNCATED AT 250 WORDS)
Effects of water temperature and salinity on elimination of Salmonella charity and Escherichia coli from Sydney rock oysters (Crassostrea commercialis)
Authors: Rowse A J , Fleet G H
Published: January 2020

The elimination of Salmonella charity and Escherichia coli from the Sydney rock oyster, Crassostrea commercialis, was examined during commercial purification of oysters under different water temperatures and salinities. Both organisms were rapidly eliminated at 18 to 22 degrees C. Purification was effective but slower at 24 to 27 degrees C and incomplete and inconsistent at temperatures below 17 degrees C. The oysters suffered stress and were not effectively purified at water salinities of 15 to 20% but were rapidly purified at 32 to 47% salinity. Winter-harvested and summer-harvested oysters were purified similarly in water at 18 to 22 degrees C and 32 to 36% salinity.
Acute toxicity of aminoglycoside antibiotics as an aid in detecting botulism
Authors: Wang Y C , Burr D H , Korthals G J , Sugiyama H
Published: January 2020

Gentamicin sulfate or neomycin sulfate injected intraperitoneally into 24- to 27-g mice at a dose of 6.2 mg per mouse elicited botulism-like responses in less than 30 min, but a dose of 3.1 mg per mouse had no observable effect. The normally nontoxic 3.1-mg aminoglycoside dose aggravated the illness induced by an earlier injection of Clostridium botulinum type A or B toxin; it was usually lethal in 2 to 20 min if the preexisting illness was moderate to severe and worsened the condition of mice for about 30 min if the preexisting botulism was mild. The aminoglycoside had no effect when given shortly after the botulinum toxin was injected intraperitoneally; the sensitized state followed a latent period. It rapidly produced botulism-like effects when given to mice which had responded to a mixture of botulinum toxin and another mouse toxic agent with an illness that did not include signs of botulism. An unexpected illness devoid of botulism-like effects was encountered during intestinal colonization of mice by C. botulinum. The appearance of botulism-like signs soon after 3.1 mg of gentamicin sulfate was injected supported other suggestions that this illness included botulism that was masked by the effects of a second cause.
Plasmids in Clostridium botulinum and related Clostridium species
Authors: Strom M S , Eklund M W , Poysky F T
Published: January 2020

Toxigenic Clostridium botulinum and nontoxigenic C. sporogenes, C. subterminale, and C. botulinum-like organisms from a variety of sources were screened for plasmids. Of the 68 toxigenic C. botulinum isolates, 56% carried one or more plasmids, ranging in mass from 2.1 to 81 megadaltons. Within individual groups (based on the type of neurotoxin produced), many strains showed identical plasmid banding patterns on agarose gels. Of the 15 nontoxigenic strains tested, 40% also carried one or more plasmids ranging from 1.7 to 25.0 megadaltons, with both unique and common banding patterns represented. A total of 67 plasmids from both toxigenic and nontoxigenic strains were detected. At this time, no phenotypic functions have been assessed for these plasmids, and they must therefore be considered cryptic. A variety of lysing and extraction techniques were necessary to detect plasmids in the different C. botulinum groups.
Measurement of the surface free energy of bacterial cell surfaces and its relevance for adhesion
Authors: Busscher H J , Weerkamp A H , van der Mei H C , van Pelt A W , de Jong H P , Arends J
Published: January 2020

An experimental technique is described to determine contact angles on bacterial layers deposited on cellulose triacetate filters. Measurements with water, water-n-propanol mixtures, and alpha-bromonaphthalene were employed to calculate surface free energies of various oral bacteria. Differences of 30 to 40 erg cm-2 were obtained for four different bacterial species isolated from the human oral cavity, if the concept of dispersion and polar surface free energies is applied. The free energies obtained were used to calculate interfacial free energies of adhesion of these bacteria from saliva onto tooth surfaces. Bacterial adhesion is energetically unfavorable, if the enamel surface free energy is less than 50 erg cm-2.
Numerical taxonomy of phenanthrene-degrading bacteria isolated from the Chesapeake Bay
Authors: West P A , Okpokwasili G C , Brayton P R , Grimes D J , Colwell R R
Published: January 2020

Phenanthrene-degrading bacteria were isolated from Chesapeake Bay samples by the use of a solid medium which had been overlaid with an ethanol solution of phenanthrene before inoculation. Eighteen representative strains of phenanthrene-degrading bacteria with 21 type and reference bacteria were examined for 123 characteristics representing physiological, biochemical, and nutritional properties. Relationships between strains were computed with several similarity coefficients. The phenogram constructed by unweighted-pair-group arithmetic average linkage and use of the simple Jaccard (SJ) coefficient was used to identify seven phena. Phenanthrene-degrading bacteria were identified as Vibrio parahaemolyticus and Vibrio fluvialis by their clustering with type and reference strains. Several phenanthrene-degrading bacteria resembled Enterobacteriaceae family members, although some Vibrio-like phenanthrene degraders could not be identified.
Influence of pH on Terminal Carbon Metabolism in Anoxic Sediments from a Mildly Acidic Lake
Authors: Phelps T. J. , Zeikus J. G.
Published: January 2020

The carbon and electron flow pathways and the bacterial populations responsible for transformation of H
2
-CO
2
, formate, methanol, methylamine, acetate, glycine, ethanol, and lactate were examined in sediments collected from Knaack Lake, Wis. The sediments were 60% organic matter (pH 6.2) and did not display detectable sulfate-reducing activity, but they contained the following average concentration (in micromoles per liter of sediment) of metabolites and end products: sulfide, 10; methane, 1,540; CO
2
, 3,950; formate, 25; acetate, 157; ethanol, 174; and lactate, 138. Methane was produced predominately from acetate, and only 4% of the total CH
4
was derived from CO
2
. Methanogenesis was limited by low environmental temperature and sulfide levels and more importantly by low pH. Increasing in vitro pH to neutral values enhanced total methane production rates and the percentage of CO
2
transformed to methane but did not alter the amount of
14
CO
2
produced from [2-
14
C]acetate (∼24%). Analysis of both carbon transformation parameters with
14
C-labeled tracers and bacterial trophic group enumerations indicated that methanogenesis from acetate and both heterolactic- and acetic acid-producing fermentations were important to the anaerobic digestion process.
Isolation and Characterization of a Novel Thermophilic, Freshwater Methanogen
Authors: Harris Jane E. , Pinn Patricia A. , Davis R. P.
Published: January 2020

A novel thermophilic, coccoid methanogen isolated from nonthermal freshwater sediments is described. Hydrogen plus carbon dioxide and formate were substrates for methanogenesis, and methane production was stimulated by yeast extract, Casamino Acids, and tryptose. Growth also occurred autotrophically. Elevated levels of sodium chloride were not required for maximum growth and were inhibitory above 2%. The minimum doubling time occurred at 57�C, and the upper and lower limits for methane production were 62 and 26�C, respectively. The optimum pH for growth was between 7.0 and 7.5. Inhibitory antibiotics included metronidazole, anisomycin, chloramphenicol, and lasalocid. Colonies were circular, dark yellow, shiny, and convex with entire edges. Cells were 1 to 2.5 μm in diameter, nonmotile, occurring singly or in pairs, and fimbriated. Cells were lysed by pronase or trypsin digestion, glass-distilled water, and 1% sodium dodecyl sulfate. Electron micrographs of thin sections showed a monolayered cell wall ca. 20 nm thick. The DNA base ratio was 49.2 mol% guanine plus cytosine. The whole cell protein pattern differed from that of other named coccoid methanogens.
Common occurrence of plasmid DNA and vancomycin resistance in Leuconostoc spp
Authors: Orberg P K , Sandine W E
Published: January 2020

Resistance to vancomycin permitted detection, in a culture of Streptococcus cremoris 290PC, of a contaminant gram-positive coccus. Morphological and physiological characteristics indicated that this bacterium was a strain of Leuconostoc sp., designated PO184. This strain contained four plasmid species, which were distinct from those harbored by S. cremoris 290PC. Antibiotic disk susceptibility tests indicated that Leuconostoc sp. strain PO184 was also resistant to sulfathiazole and trimethoprim and susceptible to 17 other antimicrobials. The MIC of vancomycin for this strain was greater than 2,000 micrograms/ml, and resistance did not depend on drug inactivation. Leuconostoc sp. strain PO184 produced a substance which was inhibitory to S. cremoris U134, but not to S. lactis ATCC 11454. Five other leuconostocs produced substances with antibacterial activity. Of 18 strains of Leuconostoc sp., 14 were resistant to at least 500 micrograms of vancomycin per ml, including four L. oenos strains which harbored no plasmid DNA in the 1- to 76-megadalton range. Twelve Leuconostoc sp. strains contained at least one plasmid species in this mass range. These findings are discussed from the physiological, taxonomical, and ecological standpoints and with regard to their potential applications.
Uncoupling by Acetic Acid Limits Growth of and Acetogenesis by
Clostridium thermoaceticum
Authors: Baronofsky Jerald J. , Schreurs Wilhelmus J. A. , Kashket Eva R.
Published: January 2020

When cells of the anaerobic thermophile
Clostridium thermoaceticum
grow in batch culture and homoferment glucose to acetic acid, the pH of the medium decreases until growth and then acid production cease, at about pH 5. We postulated that the end product of fermentation limits growth by acting as an uncoupling agent. Thus, when the pH of the medium is low, the cytoplasm of the cells becomes acidified below a tolerable pH. We have therefore measured the internal pH of growing cells and compared these values with those of nongrowing cells incubated in the absence of acetic acid. Growing cells maintained an interior about 0.6 pH units more alkaline than the exterior throughout most of batch growth (i.e., ΔpH = 0.6). We also measured the transmembrane electrical potential (ΔΨ), which decreased from 140 mV at pH 7 at the beginning of growth to 80 mV when the medium had reached pH 5. The proton motive force, therefore, was 155 mV at pH 7, decreasing to 120 mV at pH 5. When further fermentation acidified the medium below pH 5, both the ΔpH and the ΔΨ collapsed, indicating that these cells require an internal pH of at least 5.5 to 5.7. Cells harvested from stationary phase and suspended in citrate-phosphate buffer maintained a ΔpH of 1.5 at external pH 5.0. This ΔpH was dissipated by acetic acid (at the concentrations found in the growth medium) and other weak organic acids, as well as by ionophores and inhibitors of glycolysis and of the H
+
-ATPase. Nongrowing cells had a ΔΨ which ranged from about 116 mV at external pH 7 to about 55 mV at external pH 5 and which also was sensitive to ionophores. Since acetic acid, in its un-ionized form, diffuses passively across the cytoplasmic membrane, it effectively renders the membrane permeable to protons. It therefore seems unlikely that mutations at one or a few loci would result in
C. thermoaceticum
cells significantly more acetic acid tolerant than their parental type.