bluuebunny/crossref_metadata_2025 huggingface dataset:
Microfungi and Microbial Activity Along a Heavy Metal Gradient
Authors: Nordgren Anders , B��th Erland , S�derstr�m Bengt
Published: January 2020

Soil fungal biomass, microfungal species composition, and soil respiration rate of conifer mor soil were studied along a steep copper and zinc gradient (up to 20,000 μg of Cu and 20,000 μg of Zn g
−1
dry soil) around a brass mill near the town of Gusum in South Sweden. Fungal biomass and soil respiration rate decreased by about 75% along the metal gradient. Above 1,000 μg of Cu g
−1
, the decrease was clearly evident; below 1,000 μg of Cu g
−1
, no obvious effects were observed, but there was a tendency for a decrease in total mycelial length. No decrease in CFU was found along the gradient, but fungal species composition was drastically changed. The frequency of the genera
Penicillium
and
Oidiodendron
decreased from about 30 and 20%, respectively, at the control sites to only a few percent close to the mill.
Mortierella
was most frequently isolated in moderately polluted sites, but at the highest pollution levels, a decrease in isolation frequency was evident. Some fungal taxa increased in abundance towards the mill, e.g.,
Geomyces
(from 1 to 10%),
Paecilomyces
(0 to 10%), and sterile forms (from 10 to 20%). Analyses with a multivariate statistical method (partial least squares) showed that organic matter content and soil moisture had little influence on the fungal community compared with the heavy metal pollution.
Improved conversion of fumarate to succinate by Escherichia coli strains amplified for fumarate reductase
Authors: Goldberg I , Lonberg-Holm K , Bagley E A , Stieglitz B
Published: January 2020

Two recombinant plasmid Escherichia coli strains containing amplified fumarate reductase activity converted fumarate to succinate at significantly higher rates and yields than a wild-type E. coli strain. Glucose was required for the conversion of fumarate to succinate, and in the absence of glucose or in cultures with a low cell density, malate accumulated. Two-dimensional gel electrophoretic analysis of proteins from the recombinant DNA and wild-type strains showed that increased quantities of both large and small fumarate reductase subunits were expressed in the recombinant DNA strains.
In situ development of sublethal stress in Escherichia coli: effects on enumeration
Authors: Rhodes M W , Anderson I C , Kator H I
Published: January 2020

Development of sublethal stress in Escherichia coli exposed in situ to estuarine waters was examined during various seasons. An electrochemical detection technique was utilized to derive a stress index based upon the difference between a predicted electrochemical response time in Trypticase soy broth or EC medium at 44.5 degrees C estimated from a standard curve for unstressed cells and an observed response time for cells exposed to seawater. This stress index was related to recovery efficiencies of seawater-exposed cells, using a variety of standard and resuscitative enumeration procedures. Stress was further studied by determination of the adenylate energy charge. Sublethal stress as measured by the electrochemical detection method was an inverse function of water temperature, with maximum stress occurring after exposure to temperatures below 10 degrees C. Total adenylates and ATP decreased dramatically at low temperatures, although energy charge remained relatively constant under various environmental conditions. Decreases in E. coli ATP suggest that ATP may not be an adequate measure of biomass for in situ stressed cells. Discrepancies in enumeration efficiency were most pronounced at temperatures below 10 degrees C. Resuscitative procedures for solid-media techniques increased the recovery of stressed cells under cold water conditions but were not as effective as the standard most-probable-number procedure.
Isolation and Partial Characterization of Bacteriophages of the Phytopathogen
Pseudomonas syringae
Authors: Nordeen Russell O. , Morgan Michael K. , Currier Thomas C.
Published: January 2020

Bacteriophages isolated from culture supernatants of
Pseudomonas syringae
pv.
syringae
and from sewage were identified. The DNA from each phage was isolated and digested with the restriction endonuclease
Eco
RI. Eight isolates were determined to be different, with two phage isolates from sewage having restriction patterns identical to two phages from culture supernatants. The sizes of the phage DNA ranged from 24 to49 kilobases for isolates from sewage and from 39 to 52.5 kilobases for the isolates from culture supernatants. Buoyant densities of phage particles in CsCl varied from 1.498 to 1.507 g/cm
3
for isolates from sewage and from 1.506 to 1.516 g/cm
3
for isolates from culture supernatants. Electron microscopy revealed four morphological types. Based on plaque-forming ability of culture supernatants, 31 out of 47 strains of
P. syringae
are probably lysogenic.

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Plasmid Involvement in Acyclic Isoprenoid Metabolism by
Pseudomonas putida
Authors: Vandenbergh Peter A. , Wright Ann M.
Published: January 2020

An organism identified as
Pseudomonas putida
was found to utilize citronellol or geraniol as the sole carbon and energy source. The ability to degrade these acyclic isoprenols was associated with pSRQ50, a 50-megadalton transmissible plasmid.
Metabolism of T-2 toxin in Curtobacterium sp. strain 114-2
Authors: Ueno Y , Nakayama K , Ishii K , Tashiro F , Minoda Y , Omori T , Komagata K
Published: January 2020

The metabolic pathway of T-2 toxin in Curtobacterium sp. strain 114, one of the T-2 toxin-assimilating soil bacteria, was investigated by thin-layer and gas-liquid chromatographic analyses. T-2 toxin added to the basal medium as a single carbon and energy source was biotransformed into HT-2 toxin and an unknown metabolite. Infrared, mass spectrum, proton magnetic resonance, and other physico-chemical analyses identified this new metabolite as T-2 triol. T-2 toxin was first deacetylated by the bacterium into HT-2 toxin, and this metabolite was then biotransformed into T-2 triol without formation of neosolaniol and T-2 tetraol. No trichothecenes remained in the culture medium after prolonged culture. Some properties of T-2 toxin-hydrolyzing enzymes were observed with whole cells, the cell-free soluble fraction, and the culture filtrate. Besides T-2 toxin, trichothecenes such as diacetoxyscirpenol, neosolaniol, nivalenol, and fusarenon-X were also assimilated by this bacterium.
Metabolic breakdown of Kaneclors (polychlorobiphenyls) and their products by Acinetobacter sp
Authors: Furukawa K , Tomizuka N , Kamibayashi A
Published: January 2020

Biodegradability of commercial polychlorobiphenyl mixtures (Kaneclors, KC 200 to KC 500) and their metabolic products by Acinetobacter sp. strain P6 were studied by gas chromatography-mass spectrometry analysis. KC 200 (primarily dichlorobiphenyls) rapidly degraded after 4 h of incubation with the P6 resting cells, showing predominant accumulation of monochlorobenzoic acids. KC 300 (primarily trichlorobiphenyls) were also degraded after 4 h of incubation, producing various metabolic intermediates such as mono- and dichlorobenzoic acids, dihydroxy biphenyl compounds with two and three chlorines, and the ring meta-cleavage compounds with two and three chlorines. KC 400 (primarily tetrachlorobiphenyls) were also susceptible to biodegradation by the same organism. Chlorobenzoic acids (chlorine number 1 to 3), dihydroxy compounds (chlorine number 2 to 4), and the ring meta-cleavage compounds (chlorine number 2 to 3) were observed as the products from KC 400. In addition to such products, a large amount of unknown compounds with two chlorines in the molecule, which can be derived from 2,3,2',3' - or 2,3,2',5'-tetrachlorobiphenyls or both, accumulated. In contrast to KC 200, KC 300, and KC 400, KC 500 (primarily pentachlorobiphenyls) were resistant to degradation and hardly metabolized. Only dihydroxy compounds of certain pentachlorobiphenyls were detected.
Glycine betaine, an osmotic effector in Klebsiella pneumoniae and other members of the Enterobacteriaceae
Authors: Le Rudulier D , Bouillard L
Published: January 2020

Osmoregulation was examined in members of the Enterobacteriaceae. Exogenous glycine betaine at a concentration as low as 1 mM was found to stimulate the growth rate of Escherichia coli, Salmonella typhimurium, and Klebsiella pneumoniae in media of inhibitory osmotic strength. The stimulation was shown to be independent of any specific solutes, electrolytes, or nonelectrolytes. Therefore, the stimulatory effect of glycine betaine was a consequence of high osmotic potential. This effect was found to be far greater than the proline effect previously observed in S. typhimurium. Whereas nitrogen fixation by K. pneumoniae is completely inhibited under conditions of osmotic stress, nitrogenase activity could be partially restored by the addition of exogenous glycine betaine to the culture medium. Furthermore, glycine betaine in combination with proline, especially proline produced internally at a high level because of regulatory mutations affecting proline biosynthesis, strongly stimulated nitrogen fixation activity during osmotic stress. Glycine betaine was accumulated by the cells, and the amount taken up was correlated with the osmolarity of the medium. These findings are discussed in relation to the possible mechanisms by which glycine betaine might cause enhanced osmotolerance.
Comparison of β-Glucosidase Activities in Different
Streptomyces
Strains
Authors: Moldoveanu Natalia , Kluepfel Dieter
Published: January 2020

Cellobiase (β-glucosidase) production was compared for two streptomycetes:
Streptomyces flavogriseus
, a known producer of cellulase complex, and
Streptomyces
sp. strain CB-12, a strain isolated for its rapid growth on cellobiose. The optimal conditions for enzyme activity were established in relation to pH, temperature, enzyme stability, and substrate affinity. The production of β-glucosidase by the two strains depended on the carbon substrate in the medium. Cellobiose was found to repress the biosynthesis of the enzyme in
S. flavogriseus
and to stimulate its production in strain CB-12. The biosynthesis of the enzyme correlated well with the accumulation of glucose in the culture filtrates. The combined action of the β-glucosidases produced by the two
Streptomyces
strains might allow a better utilization of the reaction products which arise during the biodegradation of cellulose.
Epoxidation of Short-Chain Alkenes by Resting-Cell Suspensions of Propane-Grown Bacteria
Authors: Hou Ching T. , Patel Ramesh , Laskin Allen I. , Barnabe Nancy , Barist Irene
Published: January 2020

Sixteen new cultures of propane-utilizing bacteria were isolated from lake water from Warinanco Park, Linden, N.J. and from lake and soil samples from Bayway Refinery, Linden, N.J. In addition, 19 known cultures obtained from culture collections were also found to be able to grow on propane as the sole carbon and energy source. In addition to their ability to oxidize
n
-alkanes, resting-cell suspensions of both new cultures and known cultures grown on propane oxidize short-chain alkenes to their corresponding 1,2-epoxides. Among the substrate alkenes, propylene was oxidized at the highest rate. In contrast to the case with methylotrophic bacteria, the product epoxides are further metabolized. Propane and other gaseous
n
-alkanes inhibit the epoxidation of propylene. The optimum conditions for in vivo epoxidation are described. Results from inhibition studies indicate that a propane monooxygenase system catalyzes both the epoxidation and hydroxylation reactions. Experiments with cell-free extracts show that both hydroxylation and epoxidation activities are located in the soluble fraction obtained after 80,000 ×
g
centrifugation.
Degradation of ethylene glycol and polyethylene glycols by methanogenic consortia
Authors: Dwyer D F , Tiedje J M
Published: January 2020

Methanogenic enrichments capable of degrading polyethylene glycol and ethylene glycol were obtained from sewage sludge. Ethanol, acetate, methane, and (in the case of polyethylene glycols) ethylene glycol were detected as products. The sequence of product formation suggested that the ethylene oxide unit [HO-(CH2-CH2-O-)xH] was dismutated to acetate and ethanol; ethanol was subsequently oxidized to acetate by a syntrophic association that produced methane. The rates of degradation for ethylene, diethylene, and polyethylene glycol with molecular weights of 400, 1,000, and 20,000, respectively, were inversely related to the number of ethylene oxide monomers per molecule and ranged from 0.84 to 0.13 mM ethylene oxide units degraded per h. The enrichments were shown to best metabolize glycols close to the molecular weight of the substrate on which they were enriched. The anaerobic degradation of polyethylene glycol (molecular weight, 20,000) may be important in the light of the general resistance of polyethylene glycols to aerobic degradation.
Comparison of Degradative Ability, Enzymatic Activity, and Palatability of Aquatic Hyphomycetes Grown on Leaf Litter
Authors: Suberkropp Keller , Arsuffi Thomas L. , Anderson John P.
Published: January 2020

Stream fungi have the capacity to degrade leaf litter and, through their activities, to transform it into a more palatable food source for invertebrate detritivores. The objectives of the present study were to characterize various aspects of fungal modification of the leaf substrate and to examine the effects these changes have on leaf palatability to detritivores. Fungal species were grown on aspen leaves for two incubation times. Leaves were analyzed to determine the weight loss, the degree of softening of the leaf matrix, and the concentrations of ATP and nitrogen associated with leaves. The activities of a protease and 10 polysaccharide-degrading enzymes produced by each fungus were also determined. Most fungi caused similar changes in physicochemical characteristics of the leaves. All fungi exhibited the capability to depolymerize pectin, xylan, and cellulose. Differences among fungi were found in their capabilities to produce protease and certain glycosidases. Leaf palatability was assessed by offering leaves of all treatments to larvae of two caddisfly shredders (
Trichoptera
). Feeding preferences exhibited by the shredders were similar and indicated that they perceived distinct differences among fungi. Two fungal species were highly consumed, some moderately and others only slightly. No relationships were found between any of the fungal characteristics measured and detritivore feeding preferences. Apparently, interspecific differences among fungi other than parameters associated with biomass or degradation of structural polysaccharides influence fungal palatability to caddisfly detritivores.
Partitioning of CO
2
Fixation in the Colonial Cyanobacterium
Microcystis aeruginosa
: Mechanism Promoting Formation of Surface Scums
Authors: Paerl Hans W.
Published: January 2020

Constraints on inorganic carbon (C
i
) availability stimulated buoyancy in natural, photosynthetically active populations of the colonial blue-green alga (cyanobacterium)
Microcystis aeruginosa.
In nonmixed eutrophic river water and cultures, O
2
evolution determinations indicated C
i
limitation of photosynthesis, which was overcome either by CO
2
additions to the aqueous phase or by exposure of buoyant colonies to atmospheric CO
2
. Microautoradiographs of
M. aeruginosa
colonies revealed partitioning of
14
CO
2
fixation and photosynthate accumulation between peripheral and internal cells, particularly in large colonies. When illuminated colonies were suspended in the aqueous phase, peripheral cells accounted for at least 90% of the
14
CO
2
assimilation, whereas internal cells remained unlabeled. However, when
14
CO
2
was allowed to diffuse into colonies 15 min before illumination, a more uniform distribution of labeling was observed. Resultant differences in labeling patterns were most likely due to peripheral cells more exclusively utilizing CO
2
when ambient C
i
concentrations were low. Among colonies located at the air-water interface, internal cells showed an increased share of photosynthate production when atmospheric
14
CO
2
was supplied. This indicated that C
i
transport was restricted in large colonies below the water surface, forcing internal cells to maintain a high degree of buoyancy, thus promoting the formation of surface scums. At the surface, C
i
restrictions were alleviated. Accordingly, scum formation appears to have an ecological function, allowing cyanobacteria access to atmospheric CO
2
when the C
i
concentration is growth limiting in the water column.
Formation, Fusion, and Regeneration of Protoplasts from Wild-Type and Auxotrophic Strains of the White Rot Basidiomycete
Phanerochaete chrysosporium
Authors: Gold Michael H. , Cheng Therese M. , Alic Margaret
Published: January 2020

A preparation of two commercial enzymes was used to liberate protoplasts from 16-h-old mycelium of
Phanerochaete chrysosporium.
Regeneration frequencies of up to 5% were attained when the protoplasts were plated in a medium containing 10% sorbose and 3% agar. Fusion of protoplasts from different auxotrophic strains in polyethylene glycol-Ca
2+
produced heterokaryons. Separation of the heterokaryons into their constituent homokaryotic strains could be effected through protoplast release and formation of colonies on regeneration agar.
Ethanol Production by
Saccharomyces cerevisiae
Immobilized in Hollow-Fiber Membrane Bioreactors
Authors: Inloes Douglas S. , Taylor Dean P. , Cohen Stanley N. , Michaels Alan S. , Robertson Channing R.
Published: January 2020

Saccharomyces cerevisiae
ATCC 4126 was grown within the macroporous matrix of asymmetric-walled polysulfone hollow-fiber membranes and on the exterior surfaces of isotropic-walled polypropylene hollow-fiber membranes. Nutrients were supplied and products were removed by single-pass perfusion of the fiber lumens. Growth of yeast cells within the macrovoids of the asymmetric-walled membranes attained densities of greater than 10
10
cells per ml and in some regions accounted for nearly 100% of the available macrovoid volume, forming a tissue-like mass. A radial distribution of cell packing existed across the fiber wall, indicating an inadequate glucose supply to cells located beyond 100 μm from the lumen surface. By comparison, yeast cell growth on the exterior surfaces of the isotropic-walled membranes resulted in an average density of 3.5 × 10
9
viable cells per ml. Ethanol production by reactors containing isotropic polypropylene fibers reached a maximum value of 26 g/liter-h based on the total reactor volume. Reactor performance depended on the fiber packing density and on the glucose medium flow rate and was limited by low nutrient and product transport rates. The inhibition of ethanol production and the reduction in fermentation efficiency arose primarily from the accumulation of CO
2
gas within the sealed reactor shell space.
Rapid isolation of DNA from Staphylococcus aureus
Authors: Dyer D W , Iandolo J J
Published: January 2020

We describe a Staphylococcus aureus bulk DNA isolation procedure which uses detergent and guanidine hydrochloride to free the nucleic acid from contaminants. The procedure is rapid and yields high-molecular-weight DNA suitable for molecular biological procedures.
Isolation of Cellulolytic Actinomycetes from Marine Sediments
Authors: Veiga Manuel , Esparis Azucena , Fabregas Jaime
Published: January 2020

The cellulolytic activity of 36 actinomycetes strains isolated from marine sediments was investigated by the cellulose-azure method. Approximately 50% of the isolates exhibited various degrees of cellulolytic activity.
Flies as a source of enteric pathogens in a rural village in Thailand
Authors: Echeverria P , Harrison B A , Tirapat C , McFarland A
Published: January 2020

The village of Ban Pong in northeastern Thailand was studied from January through December 1981 to determine the importance of flies as a source of enteric pathogens. The number of flies (predominantly Musca domestica) increased in kitchens and animal pens in the hot dry spring, when the incidence of diarrhea was highest in the village. Enterotoxigenic Escherichia coli, Shigella spp., non-O1 Vibrio cholerae, and Vibrio fluvalis were isolated from fly pools in yards (69%), animal pens (38%), bathrooms (35%), and kitchens (8%). Enterotoxigenic E. coli was isolated from one fly pool in May and from another in June, when the incidence of such infections was highest in the village. Flies often carry and presumably disseminate enteric pathogens in rural Thailand.
Plasmid transfer in Pediococcus spp.: intergeneric and intrageneric transfer of pIP501
Authors: Gonzalez C F , Kunka B S
Published: January 2020

Transfer of the broad-host-range resistance plasmid pIP501 from Streptococcus faecalis to Pediococcus pentosaceus and Pediococcus acidilactici occurred between cells immobilized on nitrocellulose filters in the presence of DNase. Expression of the pIP501-linked erythromycin and chloramphenicol resistance determinants was observed in transconjugants. Intrageneric transfer of pIP501 from a P. pentosaceus donor to various pediococcal recipients occurred at frequencies of 10(-4) to 10(-7) transconjugants per input donor cell. Intergeneric transfer of plasmid pIP501 from P. pentosaceus to S. faecalis, Streptococcus sanguis (Challis), and Streptococcus lactis was observed. Similar mating experiments showed no evidence for the transfer of the broad-host-range R-plasmid pAM beta 1 to Pediococcus spp. recipients.
Thermostable NAD-linked secondary alcohol dehydrogenase from propane-grown Pseudomonas fluorescens NRRL B-1244
Authors: Hou C T , Patel R N , Laskin A I , Barist I , Barnabe N
Published: January 2020

NAD-linked alcohol dehydrogenase activity was detected in cell-free crude extracts from various propane-grown bacteria. Two NAD-linked alcohol dehydrogenases, one which preferred primary alcohols (alcohol dehydrogenase I) and another which preferred secondary alcohols (alcohol dehydrogenase II), were found in propane-grown Pseudomonas fluorescens NRRL B-1244 and were separated from each other by DEAE-cellulose column chromatography. The properties of alcohol dehydrogenase I resembled those of well-known primary alcohol dehydrogenases. Alcohol dehydrogenase II was purified 46-fold; it was homogeneous as judged by acrylamide gel electrophoresis. The molecular weight of this secondary alcohol dehydrogenase is 144,500; it consisted of four subunits per molecule of enzyme protein. It oxidized secondary alcohols, notably, 2-propanol, 2-butanol, and 2-pentanol. Primary alcohols and diols were also oxidized, but at a lower rate. Alcohols with more than six carbon atoms were not oxidized. The pH and temperature optima for secondary alcohol dehydrogenase activity were 8 to 9 and 60 to 70 degrees C, respectively. The activation energy calculated from an Arrhenius plot was 8.2 kcal (ca. 34 kJ). The Km values at 25 degrees C, pH 7.0, were 8.2 X 10(-6) M for NAD and 8.5 X 10(-5) M for 2-propanol. The secondary alcohol dehydrogenase activity was inhibited by strong thiol reagents and strong metal-chelating agents such as 4-hydroxymercuribenzoate, 5,5'-dithiobis(2-nitrobenzoic acid), 5-nitro-8-hydroxyquinoline, and 1,10-phenanthroline. The enzyme oxidized the stereoisomers of 2-butanol at an equal rate. Alcohol dehydrogenase II had good thermal stability and the ability to catalyze reactions at high temperature (85 degrees C). It appears to have properties distinct from those of previously described primary and secondary alcohol dehydrogenases.
Acidic Conditions Are Not Obligatory for Onset of Butanol Formation by
Clostridium beijerinckii
(Synonym,
C. butylicum
)
Authors: George Hugh A. , Chen J.-S.
Published: January 2020

Factors that may initiate the metabolic transition for butanol production were investigated in batch cultures of
Clostridium beijerinckii
(synonym,
Clostridium butylicum
) VPI 13436. Cultures maintained at pH 6.8 produced nearly as much butanol as those incubated without pH control, indicating that neither a change in the culture pH nor acid conditions per se are always required to initiate solvent formation. Acetate and butyrate levels at the onset of butanol production were dependent on the pH at which the cultures were maintained. Cultures maintained at pH 6.8 could be accelerated into solvent production by artificially lowering the pH to 5.0 or by the addition of acetate plus butyrate without a pH change (but neither acid alone was effective). Solvent production was associated with slower rates of growth and general metabolism, and it did not show a requirement for mature spore formation. We speculate that a slowdown in metabolism, which may be brought about by several conditions, is mechanistically related to the onset of butanol production. Extracts of solvent-producing cells contained acetoacetate decarboxylase activity as well as higher NADP
+
-linked butanol dehydrogenase and lower hydrogenase activities than extracts of acid-producing cells. Solvent production did not appear to involve an enhanced ability to catalyze H
2
oxidation.
Enzyme-Linked Immunosorbent Assays for Detection of Xylem-Limited Bacteria: Use of Trinder Reagent
Authors: Saunders Mary Starnes , French William J.
Published: January 2020

Quantitation and detection of xylem-limited bacteria with an enzyme-linked immunosorbent assay with a peroxidase conjugate is described. The use of the Trinder reagent (4-aminoantipyrine) allows the determination of extremely small quantities of peroxidase with no precipitate formation or inactivation of the enzyme by H
2
O
2
. Comparison of the enzyme-linked immunosorbent assay method with microscopic and histochemical tests for the presence of the phony peach disease bacterium in 9-year-old “June Gold” peach trees gave comparable results. The peroxidase conjugate with the Trinder reagent is more sensitive than the alkaline phosphatase conjugate typically used for enzyme-linked immunosorbent assay quantitation.
Method for recovery of enteric viruses from estuarine sediments with chaotropic agents
Authors: Wait D A , Sobsey M D
Published: January 2020

An evaluation was made of the ability of chaotropes, low-molecular-weight ionic compounds which enhance the solubilization of hydrophobic compounds in water, to improve the recovery of enteric viruses from highly organic estuarine sediments. Chaotropic agents alone were poor eluents of polioviruses from sediment but were effective when combined with 3% beef extract. Chaotropes of lower potency, NaNO3, NaCl, and KCl, were more efficient eluents than the stronger chaotropes, guanidium hydrochloride or sodium trichloroacetate. The most effective eluent was 2 M NaNO3 in 3% beef extract at pH 5.5, which eluted 71% of sediment-associated polioviruses. Efficient concentration of the sodium nitrate-beef extract eluate by organic flocculation required the addition of the antichaotrope (NH4)2SO4 to a 2 M concentration and Cat-Floc T (Calgon, Pittsburgh, Pa.) a cationic polyelectrolyte, to a 0.01% concentration. Dialysis of the final concentrate was necessary to reduce salts to nontoxic levels before assay in cell cultures. Trials with highly organic estuarine sediment seeded with high or low numbers of poliovirus 1, echovirus 1, or rotavirus SA-11 demonstrated the superiority of this method over two other methods currently in use.
Protection of Sediment-Adsorbed Transforming DNA Against Enzymatic Inactivation
Authors: Aardema Barend W. , Lorenz Michael G. , Krumbein Wolfgang E.
Published: January 2020

The action of DNase I on transforming DNA, both adsorbed to marine sediment and in solution, was investigated. DNase I reduced the transformation frequencies of free DNA more than of adsorbed DNA. Changes in salt concentration or pH did not have a significant influence on the DNA-sediment complex. Soil components other than organic materials and clay minerals can bind DNA and retard its enzymatic degradation.
Some Properties of Thiosulfate-Oxidizing Enzyme from Marine Heterotroph 16B
Authors: Tuttle Jon H. , Schwartz Julia H. , Whited Gregory M.
Published: January 2020

Thiosulfate-oxidizing enzyme has been demonstrated in cell-free extracts of the marine, thiosulfate-oxidizing pseudomonad strain 16B. The enzyme, partially purified by ion-exchange chromatography and calcium phosphate gel treatment, catalyzed the oxidation of thiosulfate to tetrathionate with the concomitant reduction of ferricyanide. Native but not mammalian cytochrome
c
was also reduced by the enzyme in the presence of thiosulfate. The enzyme was located exclusively in the supernatant of ultracentrifuged cell extracts. The most purified enzyme preparation, like intact cells, exhibited a temperature optimum of 30 to 31°C. However, it exhibited no definite pH optimum. At pH 6.1 to 6.3 and 30°C, the

K
m

for thiosulfate was 1.57 mM. At lower temperatures, the apparent

K
m

for thiosulfate increased, but the apparent maximum velocity remained virtually unchanged. Thiosulfate oxidation in intact cells exhibited an increase in the pH optimum at lower temperatures. The thiosulfate-oxidizing enzyme of marine heterotroph 16B is compared with thiosulfate-oxidizing enzymes from other bacteria, and the effect of temperature on the relationship between pH and thiosulfate oxidation is discussed with reference to the natural habitat of the bacterium.

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Isolation of Campylobacter jejuni from raw milk
Authors: Lovett J , Francis D W , Hunt J M
Published: January 2020

Campylobacter jejuni was isolated from raw milk by a method that can routinely detect less than or equal to 1 organism per ml. This procedure was used in a survey of 195 separate farms and showed a 1.5% incidence of C. jejuni in milk from bulk tanks.
Metabolism of fensulfothion by a soil bacterium, Pseudomonas alcaligenes C1
Authors: Sheela S , Pai S B
Published: January 2020

Fensulfothion (O,O-diethyl O-[4-(methylsulfinyl)phenyl]phosphorothioate), an organophosphorus pesticide used to control the golden nematode Heterodera rostochiensis, is used as a source of carbon by microorganisms isolated from soils treated with the pesticide. Two of the microbial isolates, Pseudomonas alcaligenes C1 and Alcaligenes sp. strain NC3, used more than 80% of the pesticide in 120 h in culture when supplemented as a source of carbon. P. alcaligenes C1, which showed maximal growth on fensulfothion, degraded the compound to p-methylsulfinyl phenol and diethyl phosphorothioic acid. The phenolic metabolite could be identified by conventional spectral analysis, whereas the spectral patterns of the phosphorus-containing metabolite suggested that the compound was complexed with some cellular molecules. However, utilization of the phosphoric acid ester and ethanol by P. alcaligenes C1 suggested that the microbe attacks fensulfothion by an initial hydrolysis of the compound and subsequent utilization of the phosphoric acid ester. The pathway of degradation of fensulfothion by P. alcaligenes is of great value in the detoxification of the pesticide residues and also in the environmentally stable phosphoric acid esters.
Improved Method for Isolation of Bacterial Inhibitors from Oleuropein Hydrolysis
Authors: Federici Federico , Bongi Guido
Published: January 2020

A new high-pressure liquid chromatography multidetection quantitative method for the isolation of the products of oleuropein hydrolysis is described. A single analysis yields sufficient amounts of the compounds to test their inhibitory effect on bacterial growth.
Evaluation of Nitrate Reductase Activity in
Rhizobium japonicum
Authors: Streeter John G. , DeVine Paul J.
Published: January 2020

Nitrate reductase activity was evaluated by four approaches, using four strains of
Rhizobium japonicum
and 11 chlorate-resistant mutants of the four strains. It was concluded that in vitro assays with bacteria or bacteroids provide the most simple and reliable assessment of the presence or absence of nitrate reductase. Nitrite reductase activity with methyl viologen and dithionite was found, but the enzyme activity does not confound the assay of nitrate reductase.
Cyanobacterial stimulation of growth and oxygen uptake by Legionella pneumophila
Authors: Bohach G A , Snyder I S
Published: January 2020

A laboratory-adapted strain of Legionella pneumophila grew in coculture with Fischerella. Insoluble Fischerella slime contained carbohydrate and protein and was isolated from cultures on filters. Slime-free filtrates separated into three 280-nm absorbance peaks on Sephadex G-25. Peaks 1 and 2 contained protein and carbohydrate and stimulated Legionella respiration. Peak 3 and slime had no effect.
Simple and rapid method for isolating large plasmid DNA from lactic streptococci
Authors: Anderson D G , McKay L L
Published: January 2020

A procedure for the rapid isolation of plasmid DNA larger than 30 megadaltons from lactic streptococci is described. This protocol can be used on a preparative scale to isolate sufficient quantities of plasmid DNA required for restriction analysis, cloning, or transformation experiments. A scaled-down protocol is very useful for rapidly screening the plasmid content of streptococcal strains. With this methodology, previously undetected large plasmids were observed.
Identification and Enumeration of Marine Chroococcoid Cyanobacteria by Immunofluorescence
Authors: Campbell Lisa , Carpenter Edward J. , Iacono Vincent J.
Published: January 2020

We used an indirect immunofluorescence technique to permit the identification and enumeration of individual or closely related strains of chroococcoid cyanobacteria of the general
Synechococcus
and
Synechocystis
in natural seawater samples. Antisera directed against each of five strains (two phycoerythrin-containing
Synechococcus
strains, two phycocyanin-containing
Synechococcus
strains, and one
Synechocystis
strain) were produced and tested for cross-reactions with cultures of a variety of cyanobacteria and representatives of other algae and bacteria. Each antiserum was relatively specific. The observed cross-reactions occurred between strains that were isolated from similar oceanic environments. We were able, therefore, to apply this technique to field samples. Preliminary results for April to December 1982 in Great South Bay, New York, show that
Synechocystis
populations are present only during spring and summer, phycocyanin-containing
Synechococcus
strains are only a minor component in the spring and summer, and phycoerythrin-containing
Synechococcus
populations become significant in summer and remain so until late fall or winter.
Isolation and characterization of Corynebacterium diphtheriae nontandem double lysogens hyperproducing CRM197
Authors: Rappuoli R
Published: January 2020

Phage beta 197tox-, which codes for CRM197, a nontoxic protein immunochemically indistinguishable from diphtheria toxin, was UV induced from a culture of the C7(beta 197)tox- strain. A total of 191 C7(beta 197)tox- lysogens were isolated and selected according to the halo produced on TYE agar containing antidiphtheria toxin serum and were further characterized by Southern blots of their chromosomal DNA. Most of the isolates turned out to be monolysogens, but some tandem and nontandem double lysogens were also found. The nontandem double lysogens were stable and capable of giving high yields of CRM197, up to threefold higher than monolysogens. They are, therefore, suitable for large-scale industrial production.
Purification and characterization of 1-nitropyrene nitroreductases from Bacteroides fragilis
Authors: Kinouchi T , Ohnishi Y
Published: January 2020

We isolated four nitroreductases from Bacteroides fragilis GAI0624 and examined their physicochemical and functional properties. Two major enzyme activities were found in the adsorbed and unadsorbed fractions from DEAE-cellulose column chromatography. The adsorbed fraction was subjected to Sephadex G-200 column chromatography, and two further activities were separated. One has high nitroreductase activity (nitroreductase I), and the other has low activity and relatively high molecular weight (nitroreductase III). The nitroreductase I fraction was subjected to hydroxylapatite and chromatofocusing column chromatography, and nitroreductase I was purified about 416-fold with a yield of 6.77%. The unadsorbed fraction from DEAE-cellulose column chromatography was subjected to Sepharose 2B and Sepharose 6B column chromatography. Two enzyme activities were obtained by the Sepharose 6B column chromatography. One has high activity (nitroreductase II), and the other has low activity (nitroreductase IV). Nitroreductase II was rechromatographed by Sepharose 6B gel filtration and purified about 178-fold with a yield of 9.65%. The four enzymes (nitroreductases I, II, III, and IV) were shown to be different by several criteria. Their molecular weights, determined by gel filtration, were 52,000, 320,000, 180,000, and 680,000, respectively. The substrate specificity, the effect on mutagenicity of mutagenic nitro compounds, of nitroreductases I, III, and IV was relatively high for 1-nitropyrene, dinitropyrenes, and 4-nitroquinoline 1-oxide, respectively, but nitroreductase II had broad specificity. Nitroreductase activity required a coenzyme; nitroreductases II, III, and IV were NADPH linked, but nitroreductase I was NADH linked. All enzyme activity was enhanced by addition of flavin mononucleotide and inhibited significantly by dicumarol, p-chloromercuribenzoic acid, o-iodosobenzoic acid, sodium azide, and Cu2+.(ABSTRACT TRUNCATED AT 250 WORDS)
Absence of microbial mineralization of lignin in anaerobic enrichment cultures
Authors: Odier E , Monties B
Published: January 2020

The existence of anaerobic biodegradation of lignin was examined in mixed microflora. Egyptian soil samples, in which rapid mineralization of organic matter takes place in the presence of an important anaerobic microflora, were used to obtain the anaerobic enrichment cultures for this study. Specifically, 14CO2 or [14C]lignin wood was used to investigate the release of labeled gaseous or soluble degradation products of lignin in microbial cultures. No conversion of 14C-labeled lignin to 14CO2 or 14CH4 was observed after 6 months of incubation at 30 degrees C in anaerobic conditions with or without NO3-. A small increase in soluble radioactivity was observed in certain cultures, but it could not be related to the release of catabolic products during the anaerobic biodegradation of lignin.
Assessment of bacterial growth and total organic carbon removal on granular activated carbon contactors
Authors: Bancroft K , Maloney S W , McElhaney J , Suffet I H , Pipes W O
Published: January 2020

The overall growth rate of bacteria on granular activated carbon (GAC) contactors at the Philadelphia Torresdale Water Treatment Pilot Plant facility was found to decrease until steady state was reached. The growth rate was found to fluctuate between 6.94 X 10(-3) and 8.68 X 10(-4) doublings per h. The microbiological removal of total organic carbon (TOC) was calculated by considering the GAC contactors as semiclosed continuous culture systems and using growth yield factors determined in laboratory experiments. After ozonation, the average TOC entering the contactors was 1,488 micrograms/liter, and the average effluent TOC was 497 micrograms/liter. Microbiological TOC removal was found to average 240 micrograms/liter on GAC contactors, which was not significantly different from microbiological TOC (220 micrograms/liter) removal across a parallel sand contactor where no adsorption took place. Thus, GAC did not appear to enhance biological TOC removal. Bacterial growth and maintenance was responsible for approximately 24% of the TOC removal on GAC under the conditions of this study.
Inhibition by secalonic acid D of oxidative phosphorylation and Ca2+-induced swelling in mitochondria isolated from rat livers
Authors: Kawai K , Nakamaru T , Maebayashi Y , Nozawa Y , Yamazaki M
Published: January 2020

The in vitro biological activity of secalonic acid D, a mycotoxin from Aspergillus ochraceus, was studied to assess its cytotoxicity for isolated rat liver mitochondria. Secalonic acid D uncoupled the oxidative phosphorylation of mitochondria and caused a mild inhibition of state 3 respiration. Secalonic acid D weakly enhanced latent ATPase activity in mitochondria but suppressed 2,4-dinitrophenol-stimulated ATPase activity. Secalonic acid D did not induce pseudoenergized swelling of mitochondria and markedly inhibited the Ca2+-induced swelling of mitochondria in KCl isotonic solution.
Survival and detection of rotaviruses on environmental surfaces in day care centers
Authors: Keswick B H , Pickering L K , DuPont H L , Woodward W E
Published: January 2020

Previously, we demonstrated that children in day care centers commonly experience diarrhea due to rotavirus, giardia, and bacterial pathogens. Multiple agents frequently coexist, and the environment is heavily contaminated with enteric bacteria during outbreaks. A study of environmental surface contamination with rotavirus was performed during three non-outbreak periods. Of 25 samples collected from environmental surfaces and teachers hands at a day care center, 4 (16%) were positive for rotavirus antigen when a fluorescence assay was used. We also examined the survival of two animal viruses, rotavirus SA-11 and poliovirus type 1, and bacteriophage 12 on similar environmental surfaces in a laboratory. Poliovirus type 1 and bacteriophage f2 were more resistant to drying than rotavirus SA-11 and could be recovered after a 90-min exposure on a dry surface. Rotavirus SA-11 could be detected for 30 min. All three viruses survived longer when they were suspended in fecal material than when they were suspended in distilled water. These data suggest that several agents, including rotavirus, can remain viable on contaminated surfaces long enough to be transmitted to susceptible children. This finding helps explain why rotavirus shows a mode of spread like that of parasitic and bacterial agents within day care center settings.
Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China
Authors: Olenchock S A , Christiani D C , Mull J C , Ye T T , Lu P L
Published: January 2020

Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels.
Role of Tween 80 and Monoolein in a Lipid-Sterol-Protein Complex Which Enhances Ethanol Tolerance of Sake Yeasts
Authors: Ohta Kazuyoshi , Hayashida Shinsaku
Published: January 2020

An exogenous ternary complex composed of Tween 80, ergosterol, and albumin increased the final ethanol concentration of fermentation by sake yeasts from 17.2 to 19.0% (vol/vol) and reduced the fermentation time from 30 to 25 days. Likewise, a complex of monoolein, albumin, and either ergosterol or ergosteryl oleate increased the final ethanol concentration of fermentation to 19.7 or 19.8% (vol/vol), respectively, and reduced the fermentation time to 25 days. Both Tween 80 and monoolein promoted the fermentative activity (Q

CO
2

) of cells, and the effect was enhanced by the presence of ergosterol.
Hexavalent chromium-resistant bacteria isolated from river sediments
Authors: Luli G W , Talnagi J W , Strohl W R , Pfister R M
Published: January 2020

Hexavalent chromium [Cr(VI)] is a known carcinogen and mutagen; however, the actual mechanisms of Cr toxicity are unknown. Two approaches were used to isolate Cr(VI)-resistant bacteria from metal-contaminated river sediments. Diluted sediments were plated directly onto a peptone-yeast extract (PYE) medium containing 0 to 100 micrograms of Cr(VI) ml-1. Approximately 8.4 x 10(5) CFU g-1 were recovered on 0 microgram of Cr(VI) ml-1, whereas 4.0 x 10(2) CFU g-1 were recovered on PYE plus 100 micrograms of Cr(VI) ml-1. Alternatively, continuous culture enrichment techniques were employed using PYE and 100 micrograms Cr(VI) ml-1 input at dilution rates of 0.02 and 0.10 h-1. After six residence periods, 10(9) CFU were recovered on PYE agar containing 0 microgram of Cr(VI) ml-1 and 10(7) CFU on PYE agar plus 100 micrograms of Cr(VI) ml-1. Of 89 isolates obtained by direct plating onto PYE, 47% were resistant to 100 micrograms of Cr(VI) ml-1, and 29% were resistant to 250 micrograms of Cr(VI) ml-1. When the same isolates were plated onto PYE containing Cr(III), 88% were resistant to 100 micrograms ml-1 but only 2% were resistant to 250 micrograms ml-1. Cr, Co, Sb, and Zn were found in significantly higher concentrations at an industry-related contaminated site than at a site 11 km downstream. Total Cr in the sediments at the contaminated site averaged 586 micrograms (dry weight) g-1, and the downstream site averaged 71 micrograms (dry weight) g-1. The Cr recovered from acid-digested Ottawa River sediment samples was predominantly hexavalent. Five acid digestion procedures followed by atomic absorption spectroscopy were compared and found to be 30 to 70% efficient for recovery of Cr relative to neutron activation analysis. A population of aerobic, heterotrophic bacteria was recovered from sediments containing elevated levels of Cr.(ABSTRACT TRUNCATED AT 250 WORDS)
Isolation and characterization of Campylobacter jejuni and Campylobacter coli from domestic and wild mammals in Norway
Authors: Rosef O , Gondrosen B , Kapperud G , Underdal B
Published: January 2020

A total of 1,262 domestic and wild mammals from Norway were surveyed for fecal carriage of Campylobacter jejuni and Campylobacter coli. Of the five species of domestic mammals examined, the highest isolation rate was recorded among swine (100.0%), followed by sheep (8.1%) and cows (0.8%). No strains were recovered from horses or goats. Among wild mammals, C. jejuni was isolated from 1 of 23 hares, and no isolated were obtained from three species of cervids and three species of rodents. Of the 133 Campylobacter strains isolated, 114 were classified as C. coli, 18 were C. jejuni biotype 1, and 1 belonged to C. jejuni biotype 2. All 114 strains from swine were C. coli. Milk samples from 113 domestic animals with clinically diagnosed mastitis (106 cows, 5 sheep, 1 horse, and 1 pig) were negative for campylobacters.
Modification of delayed-incubation procedure for detection of fecal coliforms in water
Authors: Chen M , Hickey P J
Published: January 2020

Three holding media, including the vitamin-free Casitone holding medium (m-VFC) recommended by Standard Methods for the Examination of Water and Wastewater for use with the delayed-incubation membrane filter procedure, were compared for their ability to maintain viability of fecal coliforms. Each medium was tested according to the procedure described in the above reference with 60 to 80 pure cultures of fecal coliforms and a variety of natural water samples containing fecal coliforms. Fecal coliform recovery with m-ST holding medium (containing ethanol, sulfanilamide, and Tris [pH 8.6] was significantly greater than recovery with m-VFC (containing vitamin-free casein hydrolysate, sodium benzoate, sulfanilamide, and ethanol). Recovery with m-VFC, was, in turn, significantly greater than with NSB medium (containing nutrient broth, boric acid, and NaCl as major ingredients). Fecal coliform counts obtained with m-ST by the delayed-incubation membrane filter procedure were higher than counts obtained by the standard immediate incubation. This result suggested that some of the sublethally injured fecal coliforms in natural water samples may have recovered during the incubation period. We propose that m-ST be used in place of m-VFC for the delayed-incubation membrane filter procedure.