bluuebunny/crossref_metadata_2025 huggingface dataset:
Shake Flask Biodegradation of 14 Commercial Phthalate Esters
Authors: Sugatt Richard H. , O'Grady Dean P. , Banerjee Sujit , Howard Philip H. , Gledhill W. E.
Published: January 2020

An acclimated shake flask CO
2
evolution test was used to study the biodegradability of 14 commercial phthalate esters that are commonly used as plasticizers. Both CO
2
evolution (ultimate biodegradation) and loss of parent phthalate esters (primary biodegradation) were measured. With only a few exceptions, primary biodegradation was 90% or higher, and ultimate biodegradation was in excess of 55% of theoretical results in 28 days. The results showed that all of the commercial phthalate esters were susceptible to biodegradation by mixed populations of microorganisms from natural sources. The results also provide considerable insight into the utility and reproducibility of a standard biodegradation test that is being recommended for widespread screening of chemicals.
Inhibition by Peptides of Amino Acid Uptake by Bacterial Populations in Natural Waters: Implications for the Regulation of Amino Acid Transport and Incorporation
Authors: Kirchman David , Hodson Robert
Published: January 2020

To investigate the regulatory interactions of amino acid transport and incorporation, we determined the effects of dipeptides on amino acid uptake by bacteria in an estuary and a freshwater lake. Dipeptides noncompetitively inhibited net transport and incorporation of amino acids into macromolecules but had no effect on the ratio of respiration to incorporation. Nearly maximum inhibition occurred at peptide concentrations of <10 nM. In contrast, the initial uptake rate of glycyl-[
14
C]phenylalanine was not affected by glycine or phenylalanine. Net amino acid transport appeared to be inhibited by the increased flux into the intracellular pools, whereas the incorporation of labeled monomers into macromolecules was isotopically diluted by the unlabeled amino acids resulting from intracellular hydrolysis of the dipeptide. Chloramphenicol, sodium azide, and dinitrophenol all inhibited the initial uptake rate of leucine and phenylalanine. These results suggest that in aquatic environments amino acids are taken up by active transport which is coupled closely to protein synthesis.
Measurements of Diel Rates of Bacterial Secondary Production in Aquatic Environments
Authors: Riemann Bo , Søndergaard Morten
Published: January 2020

Measurements of bacterial secondary production were carried out during 13 diel studies at one coastal marine station and in five lakes differing with respect to nutrient concentration and primary production. Bacterial secondary production was measured in situ every 3 to 5 h by [
3
H]thymidine incorporation into DNA. In some of the diel studies, these results were compared with results obtained from dark
14
CO
2
uptake and frequency of dividing cells. Only minor diel changes were observed. The rate of [
3
H]thymidine incorporation into DNA and the frequency of dividing cells varied from 23 to 194% of the diel mean. The dark CO
2
uptake rate varied from 12 to 259% of the diel mean. An analysis of variance demonstrated that no specific time periods during 24 h showed significantly different production rates, supporting the idea that bacterial activities in natural assemblages are controlled by a variety of events. The best correction (
r
2
= 0.74) was obtained between the [
3
H]thymidine incorporation and frequency of dividing cells procedures from the lake water samples. The actual production rates calculated by [
3
H]thymidine incorporation into DNA were appreciably lower than those obtained by the frequency of dividing cells and the dark CO
2
uptake techniques. Diel rates of bacterial production are discussed in relation to sampling frequency, statistical errors, and choice of method.
Intrinsic Bacterial Contamination of a Commercial Iodophor Solution: Investigation of the Implicated Manufacturing Plant
Authors: Berkelman Ruth L. , Anderson Roger L. , Davis Barry J. , Highsmith Anita K. , Petersen Norman J. , Bond Walter W. , Cook E. H. , Mackel Donald C. , Favero Martin S. , Martone William J.
Published: January 2020

After an outbreak of peritoneal infections attributed to intrinsic contamination of a poloxamer-iodine solution with
Pseudomonas aeruginosa
, the manufacturer of the contaminated solution permitted investigation and sampling of materials within the plant.
Pseudomonas
spp. were recovered from two different unopened lots of solution and from numerous water samples obtained at the plant. The isolates from water identical to those of an isolate recovered from Prepodyne solution (West-Agro Chemical Co., Inc., Westwood, Kans., manufactured for AMSCO Medical Products Div., Erie, Pa.) manufactured 1 month earlier at the same plant.
P. aeruginosa
was not recovered from incoming city water.
P. aeruginosa
was recovered from sterile water and poloxamer-iodine after 48 h of incubation in a plant polyvinyl chloride pipe. Scanning electron micrographs of polyvinyl chloride pipe used in the plant showed massive concentrations of rod-shaped and coccobacillary cells apparently embedded in interior deposits of the pipe. Manufacturers of iodophors should be aware that pipes or other surfaces colonized with bacteria may be a source of contamination of their products.
Microbial Growth Modification by Compressed Gases and Hydrostatic Pressure
Authors: Thom Stephen R. , Marquis Robert E.
Published: January 2020

Studies of the growth-modifying actions for
Escherichia coli, Saccharomyces cerevisiae
, and
Tetrahymena thermophila
of helium, nitrogen, argon, krypton, xenon, and nitrous oxide led to the conclusion that there are two definable classes of gases. Class 1 gases, including He, N
2
, and Ar, are not growth inhibitors; in fact, they can reverse the growth inhibitory action of hydrostatic pressures. Class 2 gases, including Kr, Xe, and N
2
O, are potent growth inhibitors at low pressures. For example, at 24°C, 50% growth-inhibitory pressures of N
2
O were found to be ca. 1.7 MPa for
E. coli
, 1.0 MPa for
S. cerevisiae
, and 0.5 MPa for
T. thermophila
. Class 1 gases could act as potentiators for growth inhibition by N
2
O, O
2
, Kr, or Xe. Hydrostatic pressure alone is known to reverse N
2
O inhibition of growth, but we found that it did not greatly alter oxygen toxicity. Therefore, potentiation by class 1 gases appeared to be a gas effect rather than a pressure effect. The temperature profile for growth inhibition of
S. cerevisiae
by N
2
O revealed an optimal temperature for cell resistance of ca. 24°C, with lower resistance at higher and lower temperatures. Overall, it appeared that microbial growth modification by hyperbaric gases could not be related to their narcotic actions but reflected definably different physiological actions.
Effects of Temperature on Methanogenesis in a Thermophilic (58°C) Anaerobic Digestor
Authors: Zinder S. H. , Anguish T. , Cardwell S. C.
Published: January 2020

The short-term effects of temperature on methanogenesis from acetate or CO
2
in a thermophilic (58°C) anaerobic digestor were studied by incubating digestor sludge at different temperatures with
14
C-labeled methane precursors (
14
CH
3
COO
−
or
14
CO
2
). During a period when
Methanosarcina
sp. was numerous in the sludge, methanogenesis from acetate was optimal at 55 to 60°C and was completely inhibited at 65°C. A
Methanosarcina
culture isolated from the digestor grew optimally on acetate at 55 to 58°C and did not grow or produce methane at 65°C. An accidental shift of digestor temperature from 58 to 64°C during this period caused a sharp decrease in gas production and a large increase in acetate concentration within 24 h, indicating that the aceticlastic methanogens in the digestor were the population most susceptible to this temperature increase. During a later period when
Methanothrix
sp. was numerous in the digestor, methanogenesis from
14
CH
3
COO
−
was optimal at 65°C and completely inhibited at 75°C. A partially purified
Methanothrix
enrichment culture derived from the digestor had a maximum growth temperature near 70°C. Methanogenesis from
14
CO
2
in the sludge was optimal at 65°C and still proceeded at 75°C. A CO
2
-reducing
Methanobacterium
sp. isolated from the digestor was capable of methanogenesis at 75°C. During the period when
Methanothix
sp. was apparently dominant, sludge incubated for 24 h at 65°C produced more methane than sludge incubated at 60°C, and no acetate accumulated at 65°C. Methanogenesis was severely inhibited in sludge incubated at 70°C, but since neither acetate nor H
2
accumulated, production of these methanogenic substrates by fermentative bacteria was probably the most temperature-sensitive process. Thus, there was a correlation between digestor performance at different temperatures and responses to temperature by cultures of methanogens believed to play important roles in the digestor.
Secondary substrate utilization of methylene chloride by an isolated strain of Pseudomonas sp
Authors: LaPat-Polasko L T , McCarty P L , Zehnder A J
Published: January 2020

Secondary substrate utilization of methylene chloride was analyzed by using Pseudomonas sp. strain LP. Both batch and continuously fed reactors demonstrated that this strain was capable of simultaneously consuming two substrates at different concentrations: the primary substrate at the higher concentration (milligrams per liter) and the secondary substrate at the lower concentration (micrograms per liter). The rate of methylene chloride utilization at trace concentrations was greater in the presence of the primary substrate, acetate, than without it. However, when the substrate roles were changed, the acetate secondary substrate utilization rate was less when methylene chloride was present. Thus, substrate interactions are important in the kinetics of secondary substrate utilization. Pseudomonas sp. strain LP showed a preference toward degrading methylene chloride over acetate, whether it was the primary or secondary substrate, providing it was below an inhibitory concentration of ca. 10 mg/liter.
Enteric bacteria in aerobically digested sludge
Authors: Farrah S R , Bitton G
Published: January 2020

Indicator bacteria, Salmonella spp., and total aerobic bacteria were determined in samples of undigested sludge and sludge that had been treated by one or two stages of aerobic digestion. Aerobic sludge digestion reduced the level of indicator bacteria by 1 to 2 log10 per g. The level of Salmonella spp. was also reduced during aerobic treatment of sludge. In general, aerobic treatment of sludge reduced, but did not eliminate, indicator bacteria and Salmonella spp.
Medium for the production of primary powder of Bacillus thuringiensis subsp. israelensis
Authors: Obeta J A , Okafor N
Published: January 2020

Five media, formulated from the seeds of five legume varieties, dried cow blood, and mineral salts, were assessed for the growth and production of insecticidal properties of Bacillus thuringiensis subsp. israelensis. Bacterial powders prepared from the broth cultures were assayed against the larvae of Aedes aegypti, Culex quinquefasciatus, and Anopheles gambiae. A standard primary powder of B. thuringiensis subsp. israelensis (IPS78) was included in the assay for comparison. Good growth was obtained in all the media, and all powders were effective against the three types of mosquito larvae. The powder containing ground seeds of Voandzeia subterranean was the most effective and compared favorably with the standard (IPS78). The concentrations required to kill 50% of the larvae of Aedes aegypti, C. quinquefasciatus, and Anopheles gambiae were 1.13 X 10(-2) +/- 1.79 X 10(-3), 1.83 X 10(-2) +/- 2.55 X 10(-3), and 2.25 X 10(-2) +/- 1.88 X 10(-3) micrograms/ml, respectively. This investigation shows that the medium containing V. subterranean can be used for the production of B. thuringiensis subsp. israelensis primary powder.
Modification of the Gelatin-Matrix Method for Enumeration of Respiring Bacterial Cells for Use with Salt-Marsh Water Samples
Authors: Newell Steven Y.
Published: January 2020

In this report I describe a modification of the gelatin-matrix method for determining the percentages of bacterial cells having active electron transport systems. This modification is one-step fluorochroming followed by use of an antioxidant solution instead of the secondary gelatin layer. The modified technique is more successfully applicable to water samples containing high densities of flocculant particulate matter, owing to the brighter green fluorescence of the cells, which contrasts with the red-orange fluorescence of the floc.
Effect of Plasmid pIJ1008 from
Rhizobium leguminosarum
on Symbiotic Function of
Rhizobium meliloti
Authors: Bedmar E. J. , Brewin N. J. , Phillips D. A.
Published: January 2020

Plasmid pIJ1008, which carries determinants for uptake hydrogenase (Hup) activity, was transferred from
Rhizobium leguminosarum
to
Rhizobium meliloti
without impairing the capacity of the latter species to form root nodules on alfalfa. The plasmid was still present in rhizobia reisolated from the root nodules of 12 different alfalfa cultivars, but only low levels of Hup activity were detected in alfalfa.
Protein synthesis in Escherichia coli during recovery from exposure to low levels of Cd2+
Authors: Mitra R S
Published: January 2020

Exposure of Escherichia coli to 3 microM Cd2+ results in 84 to 95% of the cells losing their ability to form colonies on plates of nutrient agar. Transfer of the cells to Cd2+-free liquid medium results in a recovery of colony-forming ability without significant synthesis of DNA. As an early event in recovery, the cells exhibit a rapid uptake of [3H]leucine. Recovery and this incorporation are inhibited by chloramphenicol or rifampin. Sodium dodecyl sulfate-gel electrophoresis of proteins from recovering cells labeled with [3H]leucine for 1 min indicated the synthesis of at least two classes of proteins with apparent molecular weights of 55,000 to 65,000. One class bound Cd2+ and was absent in untreated cultures. The other class of proteins, which did not bind Cd2+, was synthesized at a rapid rate in recovering cells and may be a normal cellular protein.
Liquid Chromatographic-Fluorescence Determination of Ammonia from Nitrogenase Reactions: A 2-Min Assay
Authors: Corbin James L.
Published: January 2020

The analytical potential of the reaction of ammonia with
o
-phthalaldehyde mercaptoethanol reagent at pH 7 (an atypical fluorescence) has already been demonstrated. This, coupled with additional findings reported here, has led to an ammonia determination well suited to nitrogenase studies. As a result, large numbers of samples can be rapidly analyzed by high-pressure liquid chromatrography methods under mild conditions and without prior microdiffusion. Neither sodium dithionite (or other components of the usual nitrogenase assay), nor alternative substrates (cyanide, azide, methyl isonitrile), nor their products (methylamine, dimethylamine, hydrazine) interfere. High-pressure liquid chromatography showed that the fluorescent “product” of the
o
-phthalaldehyde mercaptoethanol reagent-ammonia reaction was, in fact, more than just a single compound. Despite this, once the proper solvent composition was found, high-pressure liquid chromatography with a small inexpensive C
18
“guard” column proved quite fast and reproducible for this measurement. Fluorescence response to ammonia was linear to at least 40 nmol/ml. A previous problem, long-term stability of the fluorescence, was solved by running the reactions in the dark. Background ammonia in the buffer could be substantially reduced by an analogous
o
-phthalaldehyde mercaptoethanol reagent reaction, using
t
-butyl mercaptan, and solvent extraction.
Response of an Antarctic Lake Heterotrophic Community to High Dissolved Oxygen
Authors: Mikell Alfred T. , Parker Bruce C. , Simmons George M.
Published: January 2020

The upper waters of Lake Hoare, Antarctica, contain dissolved oxygen at about three times the normal saturation (≥42 mg liter
−1
). The response of the heterotrophic plankton community to this high dissolved oxygen was evaluated by the criteria of CFU and
d
-[
U
-
14
C]glucose assimilated-respired. High dissolved oxygen was not inhibitory to
d
-[
U
-
14
C]glucose assimilation-respiration compared with normal atmospheric dissolved oxygen in Lake Hoare water. The
d
-[
U
-
14
C]glucose was assimilated and respired optimally at 12°C in Lake Hoare. The
d
-[
U
-
14
C]glucose assimilated-respired in the upper saturated atmospheric dissolved oxygen waters of Mountain Lake, Va., was inhibited in contrast to Lake Hoare (
P
< 0.05). CFU formation was inhibited in both lakes. CFU represent <1% of the fluorochrome-stained direct counts in Lake Hoare. Lake Hoare planktobacteria are smaller than the planktobacteria in Mountain Lake. ATP size fractionation revealed that 39% of the ATP biomass was <0.5 μm in Lake Hoare.
Chemical Characterization of the Lipopolysaccharide of
Pseudomonas solanacearum
Authors: Baker C. J. , Neilson M. J. , Sequeira L. , Keegstra K. G.
Published: January 2020

The carbohydrates present in lipopolysaccharide (LPS) from
Pseudomonas solanacearum
are rhamnose, xylose, 2-amino-2-deoxyglucose, glucose, heptose, and 2-keto-3-deoxyoctonate. LPS extracted from cultures grown on either glycerol or glucose (as the major source of carbon) and extracted after various incubation periods had similar compositions. The LPS from several strains of the bacterium contained the same component sugars, but the amounts of each sugar varied considerably. It was observed, however, that xylose and 2-amino-2-deoxyglucose increased proportionately with rhamnose, the major component. Phenol-water-extracted LPS contained measurable amounts of nucleic acid, protein, and arabinan, but none of these polymers were detected in LPS extracted with phenol-chloroform-petroleum ether. Polysaccharides liberated from LPS by mild acid hydrolysis were purified by gel filtration. Carbohydrate analysis of the LPS from a virulent, fluidal strain (K60) showed that the O-specific antigen consisted of rhamnose, xylose, and 2-amino-2-deoxyglucose in the proportions 4:1:1. The LPS of an avirulent, afluidal strain (B1) lacked the O-specific antigen; the R-core region consisted of rhamnose, glucose, heptose, and 2-keto-3-deoxyoctonate. Methylation analysis indicated that the K60 O-specific antigen was composed of a hexasaccharide repeating unit containing 3-, 2-, and 3,4-substituted rhamnopyranosyl residues, 3-substituted 2-amino-2-deoxyglucose, and terminal xylopyranose in the molar ratios 2:1:1:1:1.
Effect of water activity and temperature on mycotoxin production by Alternaria alternata in culture and on wheat grain
Authors: Magan N , Cayley G R , Lacey J
Published: January 2020

Both water activity (aW) and temperature affected the production of altenuene (AE), alternariol (AOH), and alternariol monomethyl ether (AME) by Alternaria alternata on wheat extract agar and wheat grain. Greatest production of all three mycotoxins occurred at 0.98 aW and 25 degrees C on both substrates. At 0.98 aW and 25 degrees C, a single colony of A. alternata grown on wheat extract agar produced 807 micrograms of AOH, 603 micrograms of AME, and 169 micrograms of AE ml in 30 days. However, production of all three mycotoxins at 0.95 aW was less than 40% of these amounts. Little toxin was produced at 0.90 aW. Changing temperature and aW altered the relative amounts of the different toxins produced on agar. At 15 degrees C and 0.98 aW, maxima of 52 micrograms of AOH and 25 micrograms of AME per ml were produced after 15 and 30 days, respectively, whereas AE continued to increase and reached 57 micrograms/ml after 40 days. At 15 degrees C and 0.95 aW, production was, respectively, 62, 10, and 5 micrograms/ml after 40 days. All three metabolites were produced at 5 degrees C and 0.98 to 0.95 aW and at 30 degrees C and 0.98 to 0.90 aW. On wheat grain at 25 degrees C and 0.98 to 0.95 aW, more AME was produced than AOH or AE, but at 15 degrees C there was less AME than AOH or AE. Only trace amounts of AE, AOH, and AME were found at 15 to 25 degrees C and 0.90 aW, but production of AME was inhibited at 30 degrees C and 0.95 aW or less.
alpha-L-arabinofuranosidase from Ruminococcus albus 8: purification and possible role in hydrolysis of alfalfa cell wall
Authors: Greve L C , Labavitch J M , Hungate R E
Published: January 2020

An alpha-L- arabinofuranosidase has been purified from the extracellular broth of cultures of Ruminococcus albus 8. The purification procedure utilized gel filtration, (NH4)2SO4 precipitation, and isoelectric focusing. The purified enzyme appeared to be homogeneous when chromatographed on disc and analytical isoelectric focusing gels. The estimated molecular weight of the native protein was 305,000 to 310,000. Sodium dodecyl sulfate-gel electrophoresis analysis suggested that the native protein is a tetramer composed of 75,000-molecular-weight subunits. The enzyme appeared to have no metal cofactor requirement but was sensitive to several sulfhydryl reagents. The pH optimum with p-nitrophenyl-alpha-L-arabinofuranoside as the substrate was 6.9 and the Km was 1.3 mM. Several lines of evidence indicated that the enzyme is a glycoprotein. When assayed against alfalfa cell wall material, the enzyme hydrolyzed only small amounts of arabinose from the substrate. When assayed together with hemicellulolytic or pectinolytic enzymes against the same substrate, the arabinosidase significantly enhanced the hydrolytic action of the glycanases .
Muralytic Activities of
Ruminococcus albus
8
Authors: Greve L. Carl , Labavitch John M. , Stack Robert J. , Hungate Robert E.
Published: January 2020

Ruminococcus albus
8 was cultured with isolated alfalfa cell walls as the carbon source. The culture broth was assayed for muralytic enzyme activities. The effect, with respect to the production of such muralytic enzymes, of growing the microorganism on different carbon sources was also investigated. Also, the rates of solubilization and utilization by
R. albus
of individual alfalfa cell wall sugars during a 96-h growth period were examined.
Bovine Bile Resistance Increases
Leuconostoc oenos
44.40 Viability upon Lyophilization
Authors: Kole M. , Altosaar I.
Published: January 2020

A screening method based on the selection of strains of
Leuconostoc oenos
44.40 resistant to bovine bile was developed to obtain strains of the organism more resistant to lyophilization damage. These strains could be used as starter cultures in the malolactic fermentation of wine. The strain resistant to bovine bile was 20% more viable after lyophilization than strains not resistant to bovine bile. This was confirmed in both laboratory-scale production (100 ml) and pilot-scale production (100 liters). Lyophilized cells of strains sensitive and resistant to bovine bile were inoculated into wine, and the malate metabolism by the organism was monitored in the wine. Resistance to bovine bile did not change the malate metabolism characteristic of the organism. A comparison was made of the fatty acid compositions of the two strains. There was a difference in the fatty acid distribution pattern for these two strains. The bovine bile-resistant strain contained more dodecanoic, hexadecanoic, and octadecanoic acid and less tetradecanoic and hexadecanoic acid than did the bovine bile-sensitive strain. Both strains contained high levels of C-19 cyclopropane fatty acid.
Absence of transformation of beta-muricholic acid by human microflora implanted in the digestive tracts of germfree male rats
Authors: Sacquet E C , Gadelle D P , Riottot M J , Raibaud P M
Published: January 2020

Germfree rats biosynthetize cholic and beta-muricholic acids. The latter does not exist in humans. Germfree rats were given human fecal suspensions. These rats degraded cholic acid into deoxycholic acid but failed to metabolize beta-muricholic acid.
Alternative medium for Clostridium perfringens sporulation
Authors: Tórtora J C
Published: January 2020

A medium containing 0.50 g of thiotone peptone, 0.30 g of soluble starch, 0.02 g of MgSO4 X 7H2O, 0.90 g of Na2HPO4 X 2H2O, 100.00 ml of distilled water, and optionally , 166 micrograms of dichloridric thiamine supported sporulation of 138 out of 141 Clostridium perfringens strains. Comparatively this medium gave a greater percentage of sporulation than five other media described previously.
Growth of oral Streptococcus species and Actinomyces viscosus in human saliva
Authors: de Jong M H , van der Hoeven J S , van OS J H , Olijve J H
Published: January 2020

Microorganisms in dental plaque live in constant association with saliva. The role of saliva in the adherence of bacteria to the teeth and the antibacterial properties of saliva have been well investigated; less interest has been shown in the possible role of saliva as a substrate for oral microorganisms. In this study it was shown that saliva can serve as a growth medium for oral Streptococcus spp. and Actinomyces viscosus. The cell production of these organisms on saliva was carbohydrate limited. The doubling times for growth on glucose-supplemented saliva (4 to 5 mmol/liter) ranged from 1.6 to 4.0 h. The availability of carbohydrate sources for the oral microflora is discussed in relation to microbial growth in the oral cavity.
Effects of pesticides on cyanobacterium Plectonema boryanum and cyanophage LPP-1
Authors: Mallison S M , Cannon R E
Published: January 2020

Cyanobacterium Plectonema boryanum IU 594 and cyanophage LPP-1 were used as indicator organisms in a bioassay of 16 pesticides. Experiments such as spot tests, disk assays, growth curves, and one-step growth experiments were used to examine the effects of pesticides on the host and virus. Also, experiments were done in which host or virus was incubated in pesticide solutions and then assayed for PFU. P. boryanum was inhibited by four herbicides: 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 1,1-dimethyl-3-(alpha, alpha,alpha-trifluoro-m-tolyl)urea ( Fluometeron ), 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (Atrazine), 2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine ( Ametryn ). One insecticide, 2-methyl-2-(methylthio)-propionaldehyde O-( methylcarbamoyl )oxime (Aldicarb), also inhibited the cyanobacterium. Two insecticides inactivated LPP-1, O,O-dimethyl phosphorodithioate of diethyl mercaptosuccinate (malathion) and Isotox . Isotox is a mixture of three pesticides: S-[2-( ethylsulfinyl )ethyl]O,O-dimethyl phosphorothioate ( Metasystox -R), 1-naphthyl methylcarbamate ( Sevin ) and 4,4'-dichloro-alpha- (trichloromethyl) benzhydrom ( Kelthane ). Two pesticide-resistant strains of P. boryanum were isolated against DCMU and Atrazine. These mutants showed resistance to all four herbicides, which indicates a relationship between these phototoxic chemicals. The results indicate that P. boryanum may be a useful indicator species for phototoxic agents in bioassay procedures.
Effect of physiological age on radiation resistance of some bacteria that are highly radiation resistant
Authors: Keller L C , Maxcy R B
Published: January 2020

Physiological age-dependent variation in radiation resistance was studied for three bacteria that are highly radiation resistant: Micrococcus radiodurans, Micrococcus sp. isolate C-3, and Moraxella sp. isolate 4. Stationary-phase cultures of M. radiodurans and isolate C-3 were much more resistant to gamma radiation than were log-phase cultures. This pattern of relative resistance was reversed for isolate 4. Resistance of isolate 4 to UV light was also greater during log phase, although heat resistance and NaCl tolerance after heat stress were greater during stationary phase. Radiation-induced injury of isolate 4 compared with injury of Escherichia coli B suggested that the injury process, as well as the lethal process, was affected by growth phase. The hypothesis that growth rate affects radiation resistance was tested, and results were interpreted in light of the probable confounding effect of methods used to alter growth rates of bacteria. These results indicate that dose-response experiments should be designed to measure survival during the most resistant growth phase of the organism under study. This timing is particularly important when extrapolations of survival results might be made to potential irradiation processes for foods.
Influence of water quality on enteric virus concentration by microporous filter methods
Authors: Sobsey M D , Glass J S
Published: January 2020

Four enteric viruses, poliovirus type 1, echovirus type 1, reovirus type 3, and simian adenovirus SV-11, were concentrated from seeded 1.3-liter volumes of raw, finished, and granular activated carbon-treated waters by adsorption to 47-mm-diameter (17 cm2), electropositive ( Virosorb 1MDS ) filters at pH 7.5 or electronegative ( Filterite ) filters at pH 3.5 with and without 5 mM added MgCl2, followed by elution with 0.3% beef extract in 50 mM glycine at pH 9.5. Removal of particulates from raw and finished waters by 0.2-micron prefiltration before virus addition and pH adjustment had little effect on virus concentration efficiencies. Soluble organic compounds reduced virus adsorption efficiencies from both raw and finished waters compared with granular activated carbon-treated water, but the extent of interference varied with virus type and adsorption conditions. For electropositive 1MDS filters, organic interference was similar with all virus types. For Filterite filters, organic interference was evident with poliovirus and echovirus, but could be overcome by adding MgCl2. Reovirus and SV-11 were not adversely affected by organics during adsorption to Filterite filters. Elution of reovirus and adenovirus was inefficient compared with that of poliovirus and echovirus. None of the three adsorption schemes ( 1MDS at pH 7.5 and Filterite with and without 5 mM MgCl2 at pH 3.5) could be judged superior for all viruses and water types tested.
Accumulation and elimination of Escherichia coli and Salmonella typhimurium by hard clams in an in vitro system
Authors: Timoney J F , Abston A
Published: January 2020

A simple, in vitro protocol was devised to study contamination by and subsequent elimination of Escherichia coli and Salmonella typhimurium in the hard clam, Mercenaria mercenaria. The test bacteria were eliminated rapidly at similar rates for 8 h after exposure and less rapidly thereafter. At 24 h, numbers of E. coli had declined more than S. typhimurium. Bacteria were cleared in the form of rapidly sedimenting fecal and pseudofecal particulates with which the bacteria were stably associated. Ionic bonding was apparently not involved in this association. Degradation of substantial numbers of bacteria occurred in feces at between 6 and 24 h.
Characterization of pseudomonads isolated from diseased fleece
Authors: London C J , Griffith I P
Published: January 2020

A total of 59 Pseudomonas isolates was obtained from 11 samples of diseased fleece taken from live sheep. All but four of the isolates could be assigned to one of nine Pseudomonas species, of which P. aeruginosa, P. alcaligenes, P. mendocina , and P. putida were the most common. P. aeruginosa was found in four of the fleece samples and, when present, appeared to predominate. Although several of the isolates of P. aeruginosa lacked the ability to produce pyocyanin (and some produced neither pyocyanin nor fluorescein), nearly all produced several virulence factors. Of the other pseudomonads, many produced proteinase, esterase, and catalase, several were able to grow at 42 degrees C and reduce nitrate, and some also produced lipase and hemolysin and, like P. aeruginosa, might serve to initiate (or sustain) the dermatitis frequently associated with fleece rot in sheep.
Mycotoxic porcine nephropathy and spontaneous occurrence of ochratoxin A residues in kidneys and blood of Polish swine
Authors: Goliński P , Hult K , Grabarkiewicz-Szczesna J , Chełkowski J , Kneblewski P , Szebiotko K
Published: January 2020

Kidneys showing renal changes characteristic for mycotoxic porcine nephropathy were collected during the period 1 April 1982 to 31 March 1983 from 225,000 swine processed in a large slaughterhouse in the district of Poznań, Poland. Of 113 kidneys suspected of mycotoxic porcine nephropathy, 27 exhibited ochratoxin A levels from traces to 23 ng/g. In 17 kidneys the level of the toxin was lower than 2 ng/g. Increased frequency of ochratoxin A presence and its level in kidneys were observed during the spring. Of 195 porcine blood samples collected at random, 36 exhibited toxin levels from 3 to 270 ng/ml.
Caffeine inhibition of aflatoxin synthesis: probable site of action
Authors: Buchanan R L , Lewis D F
Published: January 2020

Aflatoxin production by pregrown cultures of Aspergillus parasiticus was completely inhibited by incorporation of 2 mg of caffeine per ml into the medium. This was accompanied by a decrease in glucose utilization and an inhibition of oxygen uptake and carbon dioxide evolution. Enzyme analyses indicated no significant differences in specific activities on glucose-6-phosphate dehydrogenase, mannitol dehydrogenase, phosphofructokinase, fructose 1,6-diphosphatase, pyruvate kinase, or malate dehydrogenase. Glucose uptake kinetics indicated a linear dose-related inhibition of glucose uptake. It appears likely that caffeine inhibits aflatoxin synthesis by restricting the uptake of carbohydrates which are ultimately used by the mold to synthesize this family of mycotoxins.
Agglutination Typing of
Vibrio anguillarum
Isolates from Diseased Fish and from the Environment
Authors: Larsen Jens L. , Mellergaard Stig
Published: January 2020

Agglutinating activity was widely distributed among 101
Vibrio anguillarum
strains of different origin and three
Vibrio ordalii
strains from salmonids. The spectrum of cells which were agglutinated comprised yeast cells and human (type O), poultry, guinea pig, and trout erythrocytes, whereas ovine, bovine, and tanned bovine erythrocytes were not affected. Mannose-sensitive hemagglutination, mannose-resistant hemagglutination, and non-agglutinating strains were recognized. The three
V. ordalii
strains showed mannose-resistant hemagglutination, whereas
V. anguillarum
exhibited either mannose-sensitive hemagglutination or was non-agglutinating. Among
V. anguillarum
, sensitivity to
d
-galactose and
l
-fucose occurred sporadically. An agglutination typing scheme was developed for strains of
V. anguillarum
based on the agglutination pattern of human, poultry, guinea pig, and trout erythrocytes and yeast cells. Eight different agglutination types (A through H) were defined. The distribution of these types among fish pathogenic and environmental
V. anguillarum
strains were studied. The application of the typing scheme in ecological and epidemiological studies and for preventive medical purposes is discussed.
Methane Production in Minnesota Peatlands
Authors: Williams Richard T. , Crawford Ronald L.
Published: January 2020

Rates of methane production in Minnesota peats were studied. Surface (10- to 25-cm) peats produced an average of 228 nmol of CH
4
per g (dry weight) per h at 25°C and ambient pH. Methanogenesis rates generally decreased with depth in ombrotrophic peats, but on occasion were observed to rise within deeper layers of certain fen peats. Methane production was temperature dependent, increasing with increasing temperature (4 to 30°C), except in peats from deeper layers. Maximal methanogenesis from these deeper regions occurred at 12°C. Methane production rates were also pH dependent. Two peats with pHs of 3.8 and 4.3 had an optimum rate of methane production at pH 6.0. The addition to peat of glucose and H
2
-CO
2
stimulated methanogenesis, whereas the addition of acetate inhibited methanogenesis. Cysteine-sulfide, nitrogen-phosphorus-trace metals, and vitamins-yeast extract affected methane production very little. Various gases were found to be trapped or dissolved (or both) within peatland waters. Dissolved methane increased linearly to a depth of 210 cm. The accumulation of metabolic end products produced within peat bogs appears to be an important mechanism limiting carbon turnover in peatland environments.
Processing and transport of environmental virus samples
Authors: Dahling D R , Wright B A
Published: January 2020

Poliovirus-seeded tap water, conditioned with MgCl2 and passed through virus-adsorbing filters, gave better poliovirus recovery than water identically treated but conditioned with AlCl3. Elution of several filter types with beef extract yielded higher recoveries than did elution with glycine. Seeded samples filtered through various filters and stored showed considerable virus loss in 2 days when stored at 4 degrees C, whereas those stored at -70 degrees C gave stable virus recovery up to 4 days. Additionally, the use of antifoam during the elution process reduced foaming and increased virus recovery by 28%.
Intermediary Metabolism in
Clostridium acetobutylicum
: Levels of Enzymes Involved in the Formation of Acetate and Butyrate
Authors: Hartmanis Maris G. N. , Gatenbeck Sten
Published: January 2020

The levels of seven intermediary enzymes involved in acetate and butyrate formation from acetyl coenzyme A in the saccharolytic anaerobe
Clostridium acetobutylicum
were investigated as a function of time in solvent-producing batch fermentations. Phosphate acetyltransferase and acetate kinase, which are known to form acetate from acetyl coenzyme A, both showed a decrease in specific activity when the organism reached the solvent formation stage. The three consecutive enzymes thiolase, β-hydroxybutyrylcoenzyme A dehydrogenase, and crotonase exhibited a coordinate expression and a maximal activity after growth had ceased. Only low levels of butyryl coenzyme A dehydrogenase activity were found. Phosphate butyryltransferase activity rapidly decreased after 20 h from 5 to 11 U/mg of protein to below the detection limit (1 mU/mg). Butyrate no longer can be formed, and the metabolic flux may be diverted to butanol. Butyrate kinase showed a 2.5- to 10-fold increase in specific activity after phosphate butyryltransferase activity no longer could be detected. These results suggest that the uptake of acetate and butyrate during solvent formation can not proceed via a complete reversal of the phosphate transferase and kinase reactions. The activities of all enzymes investigated as a function of time in vitro are much higher than the metabolic fluxes through them in vivo. This indicates that none of the maximal activities of the enzymes assayed is rate limiting in
C. acetobutylicum.
Identification of Nitroso Compounds from Biotransformation of 2,4-Dinitrotoluene
Authors: Liu Dickson , Thomson Karen , Anderson Ann C.
Published: January 2020

The intermediates of microbial transformation of 2,4-dinitrotoluene by a mixed bacterial culture derived from activated sludge were identified as 2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene, 2-nitroso-4-nitrotoluene, and 4-nitroso-2-nitrotoluene. The biotransformation of 2,4-dinitrotoluene occurred only under anaerobic conditions with an exogenous carbon source. The two nitroso compounds were unstable and could be observed only at the early stage of 2,4-dinitrotoluene anaerobic biotransformation.
Pigment Production from Immobilized
Monascus
sp. Utilizing Polymeric Resin Adsorption
Authors: Evans Patrick J. , Wang Henry Y.
Published: January 2020

Pigment production by the fungus
Monascus
sp. was studied to determine why
Monascus
sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor.
Monascus
cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is thought to be due to diffusional resistance of the pigment through the hydrogel beads. Addition of the adsorbent resin to the immobilized
Monascus
culture increased both the maximum pigment yield and the production rate above those of the free-cell fermentations. The provision of a support for the mycelium may explain enhanced pigment production by the solid-state culture. These results indicate that product diffusion from immobilized cell systems can be the limiting factor and that in situ extraction is one possible way to circumvent this problem.
Mutagenicity of tetramic mycotoxin cyclopiazonic acid
Authors: Sorenson W G , Tucker J D , Simpson J P
Published: January 2020

Cyclopiazonic acid was shown to be mutagenic to Salmonella typhimurium TA98 and TA100 in the presence of metabolic activation. The activity of cyclopiazonic acid in the presence of aflatoxin B1 was studied in complete factorial experiments with strain TA98. Both mycotoxins produced significant mutagenic activity and in combination. The activity in combination appeared to be additive rather than synergistic. The specific activity of cyclopiazonic acid was estimated to be approximately 140 revertants per mu mol in strain TA98.
Role of
N
-Acetylgalactosamine-Specific Protein in Trapping of Nematodes by
Arthrobotrys oligospora
Authors: Premachandran Devidas , Pramer David
Published: January 2020

An
N
-acetylgalactosamine-specific protein was purified from mycelial homogenates of the nematode-trapping fungus
Arthrobotrys oligospora
by using affinity chromatography. The molecular weight of the protein was estimated at 22,000 by its comparative mobility on sodium dodecyl sulfate-polyacrylamide slab gels. Pretreatment of nematodes with the purified protein reduced entrapment, indicating a role for the sugar-binding protein in recognition and capture of prey by the fungus.
Colonization of the axilla by Propionibacterium avidum in relation to age
Authors: Nordstrom N K , Noble W C
Published: January 2020

The prevalence of Propionibacterium avidum in the axillae of 248 individuals aged 5 to 18 years was studied. Both caucasoids and negroids, males (132) and females (116), were included. The frequency of recovery of the organism increased with age and was associated with the onset of puberty. The organism was recovered from only 2 of 40 females (5%) aged 5 to 10 years and from 1 of 22 males (4.5%), whereas 45% of females and 58% of males aged 15 to 16 years were colonized. Females tended to become colonized at an earlier age than males did. It appeared that negroids carried the organism more frequently than caucasoids, but the difference in prevalence was not statistically significant in matching age groups. It is suggested that the increase of hydration of the axilla with age and increase in substrate availability play an important part in the colonization process.
Sustained Photoproduction of Ammonia from Dinitrogen and Water by the Nitrogen-Fixing Cyanobacterium
Anabaena
sp. Strain ATCC 33047
Authors: Ramos Juan L. , Guerrero Miguel G. , Losada Manuel
Published: January 2020

Conditions have been developed that lengthen the time during which photosynthetic dinitrogen fixation by filaments of the cyanobacterium
Anabaena
sp. strain ATCC 33047 proceeds freely, whereas the subsequent conversion of ammonia into organic nitrogen remains blocked, with the resulting ammonia released to the outer medium. When
l
-methionine-
dl
-sulfoximine was added every 20 h, maximal rates of ammonia production (25 to 30 μmol/mg of chlorophyll per h) were maintained for about 50 h. After this time, ammonia production ceased due to a deficiency of glutamine and other nitrogenous compounds in the filaments, conditions which finally led to cell lysis. The effective ammonia production period could be further extended to about 7 days by adding a small amount of glutamine at the end of a 40-h production period or by allowing the cells to recover for 8 h in the absence of
l
-methionine-
dl
-sulfoximine after every 40-h period in the presence of the inhibitor. A more prolonged steady production of ammonia, lasting for longer than 2 weeks, was achieved by alternating treatments with the glutamine synthetase inhibitors
l
-methionine-
dl
-sulfoximine and phosphinothricin, provided that 8-h recovery periods in the absence of either compound were also alternated throughout. The biochemically manipulated cyanobacterial filaments thus represent a system that is relatively stable with time for the conversion of light energy into chemical energy, with the net generation of a valuable fuel and fertilizer through the photoreduction of dinitrogen to ammonia.
Evolution of Acetic Acid Bacteria During Fermentation and Storage of Wine
Authors: Joyeux A. , Lafon-Lafourcade S. , Ribéreau-Gayon P.
Published: January 2020

Acetic acid bacteria were present at all stages of wine making, from the mature grape through vinification to conservation. A succession of
Gluconobacter oxydans, Acetobacter pasteurianus
, and
Acetobacter aceti
during the course of these stages was noted. Low levels of
A. aceti
remained in the wine; they exhibited rapid proliferation on short exposure of the wine to air and caused significant increases in the concentration of acetic acid. Higher temperature of wine storage and higher wine pH favored the development and metabolism of these species.
Evaluation of subsampling and fixation procedures used for counting rumen protozoa
Authors: Dehority B A
Published: January 2020

Total numbers of protozoa can be significantly lower in rumen fluid than in whole rumen contents, depending on the time of sampling and the procedure used to separate the fluid and solid fractions. Moreover, generic distribution in rumen fluid was significantly affected in all cases tested. The percentage of Entodinium spp. increased, whereas percentages of Diplodinium spp. and Ophryoscolex spp. decreased. Microscopic observation of fresh and fixed rumen contents did not indicate any marked attachment of protozoa to particulate matter. In addition, dilution of whole rumen contents with water, 5 mM sucrose, or 0.1% Tween 80 before fixation did not affect total numbers or generic composition of protozoa. It was thus concluded that attachment to feed particles is probably not a problem in counting procedures. Blending of whole rumen contents to facilitate subsampling caused a decrease in numbers of protozoa. The concentration of formaldehyde used for preservation of rumen contents, 4, 10, or 18.5%, did not affect the total count.
Relative Contributions of Bacteria and Fungi to Rates of Degradation of Lignocellulosic Detritus in Salt-Marsh Sediments
Authors: Benner Ronald , Newell S. Y. , Maccubbin A. E. , Hodson Robert E.
Published: January 2020

Specifically radiolabeled [
14
C-lignin]lignocellulose and [
14
C-polysaccharide]lignocellulose from the salt-marsh cordgrass
Spartina alterniflora
were incubated with an intact salt-marsh sediment microbial assemblage, with a mixed (size-fractionated) bacterial assemblage, and with each of three marine fungi,
Buergenerula spartinae, Phaeosphaeria typharum
, and
Leptosphaeria obiones
, isolated from decaying
S. alterniflora.
The bacterial assemblage alone mineralized the lignin and polysaccharide components of
S. alterniflora
lignocellulose at approximately the same rate as did intact salt-marsh sediment inocula. The polysaccharide component was mineralized twice as fast as the lignin component; after 23 days of incubation, ca. 10% of the lignin component and 20% of the polysaccharide component of
S. alterniflora
lignocellulose were mineralized. Relative to the total sediment and bacterial inocula, the three species of fungi mediated only very slow mineralization of the lignin and polysaccharide components of
S. alterniflora
lignocellulose. Experiments with uniformly
14
C-labeled
S. alterniflora
material indicated that the three fungi and the bacterial assemblage were capable of degrading the non-lignocellulosic fraction of
S. alterniflora
material, but only the bacterial assemblage significantly degraded the lignocellulosic fraction. Our results suggest that bacteria are the predominant degraders of lignocellulosic detritus in salt-marsh sediments.