bluuebunny/crossref_metadata_2025 huggingface dataset:
Rates of Microbial Transformation of Polycyclic Aromatic Hydrocarbons in Water and Sediments in the Vicinity of a Coal-Coking Wastewater Discharge
Authors: Herbes Stephen E.
Published: January 2020

To facilitate predictions of the transport and fate of contaminants at future coal conversion facilities, rates of microbial transformation of polycyclic aromatic hydrocarbons were measured in stream water and sediment samples collected in the vicinity of a coal-coking treated wastewater discharge from November 1977 through August 1979. Six radiolabeled polycyclic aromatic hydrocarbons were incubated with sediment and water samples;
14
CO
2
, cell-bound
14
C, and polar transformation products were isolated and quantified. Whereas
14
CO
2
and bound
14
C were major transformation products in sediment assays, soluble polar
14
C dominated transformation in water samples. Mean rate constants (measured at 20°C) in sediments collected downstream from the effluent outfall were 7.8 × 10
−2
h
−1
(naphthalene), 1.6 × 10
−2
h
−1
(anthracene), and 3.3 × 10
−3
h
−1
[benz(a)anthracene], which corresponded to turnover times of 13, 62, and 300 h, respectively. No unequivocal evidence for transformation of benzo(a)pyrene or dibenz(a,h)anthracene was obtained. Only naphthalene and anthracene transformations were observed in water samples; rate constants were consistently 5- and 20-fold lower, respectively, than in the corresponding sediment samples. The measured rate constants for anthracene transformation in July 1978 sediment samples were not related to total heterotroph numbers. In late July 1978, the effluent was diverted from the primary study area; however, no differences were observed either in transformation rate constants or in the downstream/upstream sediment rate constant ratio. These results are consistent with the hypothesis that continuous inputs of polycyclic aromatic hydrocarbons result in an increased ability within a microbial community to utilize certain polycyclic aromatic hydrocarbons. However, because transformation rates remained elevated for more than 1 year after removal of the polycyclic aromatic hydrocarbon source, microbial communities may shift only slowly in response to changes in polycyclic aromatic hydrocarbon concentrations.
Root-Associated N
2
Fixation (Acetylene Reduction) by
Enterobacteriaceae
and
Azospirillum
Strains in Cold-Climate Spodosols
Authors: Haahtela Kielo , Wartiovaara Tuula , Sundman Veronica , Skujiņš J.
Published: January 2020

N
2
fixation by bacteria in associative symbiosis with washed roots of 13
Poaceae
and 8 other noncultivated plant species in Finland was demonstrated by the acetylene reduction method. The roots most active in C
2
H
2
reduction were those of
Agrostis stolonifera, Calamagrostis lanceolata, Elytrigia repens
, and
Phalaris arundinacea
, which produced 538 to 1,510 nmol of C
2
H
4
·g
−1
(dry weight)· h
−1
when incubated at pO
2
0.04 with sucrose (pH 6.5), and 70 to 269 nmol of C
2
H
4
· g
−1
(dry weight)·h
−1
without an added energy source and unbuffered.
Azospirillum lipferum, Enterobacter agglomerans, Klebsiella pneumoniae
, and a
Pseudomonas
sp. were the acetylene-reducing organisms isolated. The results demonstrate the presence of N
2
-fixing organisms in associative symbiosis with plant roots found in a northern climatic region in acidic soils ranging down to pH 4.0.
Microbiota Associated with the Gastrointestinal Tract of the Common House Cricket,
Acheta domestica
Authors: Ulrich R. G. , Buthala D. A. , Klug M. J.
Published: January 2020

The location and morphology of the bacteria associated with the gastrointestinal tract of
Acheta domestica
were studied, and these bacteria were partially characterized. Bacteria were associated with the peritrophic membrane in the midgut and with the gut wall and cuticular structures of the hindgut. No bacteria were associated with the fat bodies. Colony-forming unit determinations indicated that there were three times more cultivatable bacteria in the hindgut than in the midgut. Of these bacteria, 40 to 85% cleared uric acid anaerobically, and 90 to 100% cleared uric acid aerobically. Of the 25 isolates obtained, 21 belonged to the genera
Citrobacter, Klebsiella, Yersinia, Bacteroides
, and
Fusobacterium.
Yersinia enterocolitica in raw goat's milk
Authors: Hughes D , Jensen N
Published: January 2020

Biochemical and serological data are presented for 35 isolates of Yersinia enterocolitica from raw goat's milk produced in New South Wales, Australia. Strains resembled biotype I or 2, but the majority (25 of 35) fermented rhamnose and some showed other atypical reactions.
Antibiotic Sensitivities In Vitro of Diverse Spiroplasma Strains Associated with Plants and Insects
Authors: Davis R. E.
Published: January 2020

Fifteen spiroplasma strains, representing five serological subgroups classified in three distinct serogroups, and four strains unassigned to serogroups were examined for sensitivity to antibiotics. The data contribute to the characterization of spiroplasmas and enlarge comparisons between plant pathogenic strains and strains that are evidently a part of the normal epiphytic microflora.
Purification and Some Properties of Diplococcin from
Streptococcus cremoris
346
Authors: Davey G. P. , Richardson B. C.
Published: January 2020

Eleven of 150
Streptococcus cremoris
strains examined produced the bacteriocin diplococcin. The diplococcin activity spectrum was restricted to
S. cremoris
and
Streptococcus lactis
strains, and none of a wide range of other gram-positive or gram-negative strains were inhibited. The diplococcin produced by
S. cremoris
346 was purified by ammonium sulfate precipitation and column chromatography. Purified diplococcin was very unstable at room temperature and lost 75% of its activity after heating at 100°C for 1 min. The proteolytic enzymes trypsin, pronase, and α-chymotrypsin completely inactivated diplococcin. The amino acid composition showed a high content of acidic and neutral acids and a correspondingly low content of basic amino acids, including one residue of ornithine per mole. From the amino acid analysis a molecular weight of 5,300 was estimated. Diplococcin was readily distinguished from the
S. lactis
bacteriocin nisin by its restricted activity spectrum, its biological properties, and by cross-reaction experiments.
Poplar Lignin Decomposition by Gram-Negative Aerobic Bacteria
Authors: Odier E. , Janin G. , Monties B.
Published: January 2020

Eleven gram-negative aerobic bacteria (
Pseudomonadaceae
and
Neisseriaceae
) out of 122 soil isolates were selected for their ability to assimilate poplar dioxane lignin without a cosubstrate. Dioxane lignin and milled wood lignin degradation rates ranged between 20 and 40% of initial content after 7 days in mineral medium, as determined by a loss of absorbance at 280 nm; 10 strains could degrade in situ lignin, as evidenced by the decrease of the acetyl bromide lignin content of microtome wood sections. No degradation of wood polysaccharides was detected. Lignin biodegradation by
Pseudomonas
106 was confirmed by
14
CO
2
release from labeled poplar wood, although in lower yields compared with results obtained through chemical analysis based on acetyl bromide residual lignin determination.
Anaerobic Degradation of Lactate by Syntrophic Associations of
Methanosarcina barkeri
and
Desulfovibrio
Species and Effect of H
2
on Acetate Degradation
Authors: McInerney Michael J. , Bryant Marvin P.
Published: January 2020

When grown in the absence of added sulfate, cocultures of
Desulfovibrio desulfuricans
or
Desulfovibrio vulgaris
with
Methanobrevibacter smithii
(
Methanobacterium ruminantium
), which uses H
2
and CO
2
for methanogenesis, degraded lactate, with the production of acetate and CH
4
. When
D. desulfuricans
or
D. vulgaris
was grown in the absence of added sulfate in coculture with
Methanosarcina barkeri
(type strain), which uses both H
2
-CO
2
and acetate for methanogenesis, lactate was stoichiometrically degraded to CH
4
and presumably to CO
2
. During the first 12 days of incubation of the
D. desulfuricans-M. barkeri
coculture, lactate was completely degraded, with almost stoichiometric production of acetate and CH
4
. Later, acetate was degraded to CH
4
and presumably to CO
2
. In experiments in which 20 mM acetate and 0 to 20 mM lactate were added to
D. desulfuricans-M. barkeri
cocultures, no detectable degradation of acetate occurred until the lactate was catabolized. The ultimate rate of acetate utilization for methanogenesis was greater for those cocultures receiving the highest levels of lactate. A small amount of H
2
was detected in cocultures which contained
D. desulfuricans
and
M. barkeri
until after all lactate was degraded. The addition of H
2
, but not of lactate, to the growth medium inhibited acetate degradation by pure cultures of
M. barkeri.
Pure cultures of
M. barkeri
produced CH
4
from acetate at a rate equivalent to that observed for cocultures containing
M. barkeri.
Inocula of
M. barkeri
grown with H
2
-CO
2
as the methanogenic substrate produced CH
4
from acetate at a rate equivalent to that observed for acetate-grown inocula when grown in a rumen fluid-vitamin-based medium but not when grown in a yeast extract-based medium. The results suggest that H
2
produced by the
Desulfovibrio
species during growth with lactate inhibited acetate degradation by
M. barkeri.
Nisin: a possible alternative or adjunct to nitrite in the preservation of meats
Authors: Rayman M K , Aris B , Hurst A
Published: January 2020

Nisin at 75 ppm (75 microgram/g) was superior to 150 ppm of nitrite in inhibiting outgrowth of Clostridium sporogenes PA3679 spores in meat slurries, which had been heated to simulate the process used for cooked ham. The inhibitory activity of nisin decreased as the spore load or pH of the slurries increased. Unlike nitrite, inhibition by nisin was unaffected by high levels of iron either as a constituent of meats or when added as an iron salt. In slurries treated with 75 ppm of nisin, refrigerated storage for 56 days resulted in depletion of nisin to a level low enough to allow outgrowth within 3 to 10 days if the slurries were subsequently abused at 35 degrees C. In contrast, a combination of 40 ppm of nitrite and either 75 or 100 ppm of nisin almost completely inhibited outgrowth in these slurries. The nisin-nitrite combination appeared to have a synergistic effect, and the low concentration of nitrite was sufficient to preserve the color in meats similar to that of products cured with 150 ppm of nitrite.
Temporal Changes in a Pink Feedlot Lagoon
Authors: Wenke Thomas L. , Vogt Judith C.
Published: January 2020

Temporal changes in a feedlot drainage lagoon with a predominance of the phototrophic purple sulfur bacterium,
Thiopedia rosea
, were investigated during a 3-year period. The surface protein and bacteriochlorophyll concentrations, which indirectly measure
T. rosea
abundance, peaked annually during the fall months and coincided with the intensity of pink coloration. Surface bacteriochlorophyll concentration correlated with pH, alkalinity, and protein. The pH range was optimal for the survival of
T. rosea.
Surface sulfide concentration, which increased over the winter and early spring, reached low levels during the fall months. The most striking pattern to emerge was the marked increase in sulfate concentration that occurred each fall and winter. The protein peaks, which preceded the sulfate peaks, were indicative of the sulfate concentrations that would follow. During 1977 and 1978, the lagoon was essentially anaerobic and provided adequate growth conditions for
T. rosea.
Above-average precipitation during early 1979 raised the water level and altered the chemistry of the lagoon. Dissolved oxygen was higher during the final year, and, concurrently, concentrations of bacteriochlorophyll declined. Aeration of the lagoon resulted in a decrease in
T. rosea.
Superoxide dismutase activity in thermally stressed Staphylococcus aureus
Authors: Bucker E R , Martin S E
Published: January 2020

The effects of heat and NaCl on the activity of superoxide dismutase from Staphylococcus aureus were examined. A linear decrease in superoxide dismutase activity occurred when S. aureus MF-31 cells were thermally stressed for 90 min at 52% C in 100 mM potassium phosphate buffer (pH 7.2). After 20 min of heating, only 5% of the superoxide dismutase activity was lost. Heating for 60, 90 and 120 min resulted in decreases of approximately 10, 22, and 68%, respectively. The rates of thermal inactivation of superoxide dismutase from S. aureus strains 196E and 210 were similar and slightly greater than those of strains MF-31, S-6, and 181. The addition of NaCl before or after heating resulted in increased losses of superoxide dismutase activity.
Urea-lysine method for recovery of enteroviruses from sludge
Authors: Farrah S R , Scheuerman P R , Bitton G
Published: January 2020

Enteroviruses added to sludge and indigenous viruses present in sludge were recovered by treating the sludge flocs with a 4 M urea solution buffered at pH 9 with 0.5 M lysine. Eluted viruses were absorbed to aluminum hydroxide flocs and collected by centrifugation. The flocs were solubilized with 0.1 M ethylenediaminetetraacetic acid-3% beef extract at pH 9. After dialysis to remove the ethylenediaminetraacetic acid, viruses were further concentrated by organic flocculation. Approximately 40% of poliovirus and coxsackievirus B-3 added to 500 to 1,000 ml of sludge could be recovered in final sample volumes of less than 10 ml. Polioviruses, echoviruses, and coxsackieviruses were recovered from different samples of wastewater sludge.
Tin and Tin-Resistant Microorganisms in Chesapeake Bay
Authors: Hallas L. E. , Cooney J. J.
Published: January 2020

Sediment and water samples from nine stations in Chesapeake Bay were examined for tin content and for microbial populations resistant to inorganic tin (75 mg of Sn liter
−1
as SnCl
4
·5H
2
O) or to the organotin compound dimethyltin chloride [15 mg of Sn liter
−1
as (CH
3
)
2
SnCl
2
]. Tin concentrations in sediments were higher (3.0 to 7.9 mg kg
−1
) at sites impacted by human activity than at open water sites (0.8 to 0.9 mg kg
−1
), and they were very high (239.6 mg kg
−1
) in Baltimore Harbor, which is impacted by both shipping and heavy industry. Inorganic tin (75 mg Sn liter
−1
) in agar medium significantly decreased viable counts, but its toxicity was markedly reduced in liquid medium; it was not toxic in medium solidified with silica gel. Addition of SnCl
4
·5H
2
O to these media produced a tin precipitate which was not involved in the metal's toxicity. The data suggest that a soluble tin-agar complex which is toxic to cells is formed in agar medium. Thus, the toxicity of tin depends more on the chemical species than on the metal concentration in the medium. All sites in Chesapeake Bay contained organisms resistant to tin. The microbial flora was more sensitive to (CH
3
)
2
SnCl
2
than to SnCl
4
·5H
2
O. The elevated level of tin-resistant microorganisms in some aeas not containing unusually high tin concentrations suggests that factors other than tin may participate in the selection for a tin-tolerant microbial flora.
Microbiological, Biochemical, and Electron Microscopic Characterization of a
Pectinatus
Strain
Authors: Haikara Auli , Penttilä Liisa , Enari T.-M. , Lounatmaa K.
Published: January 2020

A spoilage organism isolated from turbid beer is described. The bacterium was gram negative, catalase negative, strictly anaerobic, and rod shaped, having flagella only on one side of the cell. The main metabolic product was propionic acid. In addition acetic, succinic, and lactic acids and acetoin were formed. Malonate inhibited the production of propionic acid by the strain studied and by both
Pectinatus
and
Propionibacterium
strains. The guanine-plus-cytosine content of deoxyribonucleic acid was 36 mol%. Differences between this strain and
Pectinatus
strains were 2 to 5 percentage points. Immunofluorescent staining and gel diffusion precipitin tests revealed that the antigenic structure differed from those of
Pectinatus
strains. The isolated organism can, despite some differences, be regarded as belonging to the genus
Pectinatus.
Isolation of Vibrio cholerae serotype O1 from the eastern oyster, Crassostrea virginica
Authors: Hood M A , Ness G E , Rodrick G E
Published: January 2020

Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination.
Physiological Criteria and Mycotoxin Production as Aids in Identification of Common Asymmetric Penicillia
Authors: Frisvad Jens C.
Published: January 2020

The taxonomy of the asymmetric (predominantly terverticillate) penicillia is based on morphological differences that leave identification difficult. The application of physiological criteria facilitated the identification of the common asymmetric penicillia investigated. Changes in the placement of some strains of these penicillia made the connection to mycotoxin-producing ability clearer. The classical criterion of conidium color was deemphasized and replaced by the following criteria: (i) growth on nitrite-sucrose agar and (ii) growth and acid (and subsequent base) production on creatine-sucrose agar (containing bromocresol purple). Other criteria used or developed were: (iii) growth on sorbic acid plus benzoic acid agar (50 + 50 ppm, pH 3.8), (iv) growth on an agar containing 1,000 ppm propionic acid (pH 3.8), (v) growth on an agar containing 0.5% acetic acid, (vi) growth at 37°C, (vii) growth rate on an agar containing 0.1% pentachloronitrobenzene, (viii) production of extracellular tricaproinase, and (ix) fasciculation on a medium containing 10 ppm botran (2,6-dichloro-4-nitroanilin). The pattern of extracellular metabolites after thin-layer chromatography was used as a chemotaxonomic criterion. The species investigated, the number of isolates investigated, and the toxins which some of these isolates produce were:
Penicillium roqueforti
(18) (patulin),
P. citrinum
(11) (citrinin),
P. patulum
(9) (patulin and griseofulvin),
P. expansum
(patulin and citrinin),
P. hirsutum
(13),
P. brevicompactum
(19), and
P. chrysogenum
(12). Widespread species of the
P. cyclopium, P. viridicatum
, and
P. expansum
series of Raper and Thom (
A Manual of the Penicillia
, 1949) were subdivided into four new groups: “P. crustosum pA” (29) (penitrem A), “P. melanochlorum” (29), “P. cyclopium p” (119) (penicillic acid and infrequently penitrem A), and “P. viridicatum o-c” (43) (ochratoxin A and citrinin). “P. viridicatum o-c” was separated from “P. cyclopium p” due to its ability to grow on nitrite as sole nitrogen source. The species and groups investigated were related to the new taxonomic classification of the genus
Penicillium
according to Pitt.
Factors affecting salmonellae repopulation in composted sludges
Authors: Russ C F , Yanko W A
Published: January 2020

The repopulation potential and recovery of Salmonella sp. and their close relatives Arizona spp. and Citrobacter spp. in sewage sludge which had been composted was examined. Salmonellae growth in previously composted sludge was found to occur in the mesophilic temperature range (20 to 40 degrees c), require a moisture content of greater than or equal to 20%, and require a carbon/nitrogen ratio in excess of 15:1.
Persistence of human rhinovirus infectivity under diverse environmental conditions
Authors: Reagan K J , McGeady M L , Crowell R L
Published: January 2020

The persistence of human rhinovirus type 2 and type 14 infectivity was studied under various laboratory conditions designed to mimic those commonly found in the environment. The effects of temperature, ionic strength, protein content, and evaporation were compared. Both viruses were stable (less than 0.3-log decrease in titer) at 6 and 23 degrees c for 24 h in the liquid state regardless of salt or protein additives; a titer decrease of less than 1.0 log was noted at 37 degrees C. However, evaporation at 37 degrees C reduced virus infectivity by 3.2 to 4.5 logs in buffered water, an effect which could be significantly lessened by the addition of bovine serum albumin in saline (2.0- to 2.9-log decrease in titer). These studies support and extend observations by others that the human rhinoviruses retain sufficient infectivity after drying on hard surfaces to permit their transmission to susceptible persons upon contact.
Distribution of viruses associated with particles in waste water
Authors: Hejkal T W , Wellings F M , Lewis A L , LaRock P A
Published: January 2020

The distribution of solids-associated viruses in wastewater was studied to determine the effect of treatment processes on viruses associated with solids. Solids less than 0.3 micrometers in diameter were separated from the liquid phase of each sample by using a continuous-flow centrifuge. The percentage of virus associated with solids larger than 0.3 micrometers decreased from 28% in the influent to 3.4% in unchlorinated effluent, and this was accompanied by a 92% decrease in the total concentration of virus. These results indicate that the original solids-associated virus as well as that is secondarily adsorbed to mixed liquor-suspended solids is lost during clarification. The total concentration of virus was reduced by 82% by chlorination, and the percentage of virus associated with solids increased to 7.7% upon chlorination, indicating some protection due to association with particles larger than 0.3 micrometers. When a suspension of fecal particles and a 0.22-micrometers filtrate of a fecal homogenate were sonicated, a threefold increase in virus titer was observed in each. This demonstrated that viruses may be attached to particles smaller than 0.22 micrometers. Thus, small viral aggregates or viruses attached to submicron particles represented the major portion of solids-associated virus in treated sewage.
Biochemical characteristics and identification of Enterobacteriaceae isolated from meats
Authors: Stiles M E , Ng L K
Published: January 2020

The isolation and identification of 2,220 Enterobacteriaceae from meats indicated that Escherichia coli biotype I, Enterobacter agglomerans, and Serratia liquefaciens were the principal types to be differentiated in meats. Citrobacter freundii, Klebsiella pneumoniae, Enterobacter cloacae, and Enterobacter hafniae were also commonly identified. Identification of isolates by the Encise II (Roche Diagnostics Inc., Nutley, N.J.) and Minitek (BBL Microbiology Systems, Cockeysville, Md.) coding systems gave similar results with only 255 (11.5%) discrepancies in identity, but both systems required large numbers of supplementary tests for identification of the isolates. Not only the distribution of Enterobacteriaceae types isolated from meats but also some of the biochemical reactions of the isolates differed from those of clinical isolates. The Minitek technique is recommended because of its versatility. However, with the addition of cellobiose and salicin disks and the inclusion of methyl red to the Minitek test and the use of the Voges-Proskauer test and gas production in EC medium at elevated temperature as standard tests, the identification of these Enterobacteriaceae from meats would be greatly facilitated. The inclusion of the motility test, for example, using nitrate motility agar, would also be of value to Enterobacteriaceae identification.
Solar radiation induces sublethal injury in Escherichia coli in seawater
Authors: Kapuscinski R B , Mitchell R
Published: January 2020

Sublethal injury was noted in Escherichia coli after cells were exposed to solar radiation. Injury was detected by differential plate counts between complete and minimal media that were observed with sunlight-exposed cells but not with cells kept in the dark. Since addition of catalase or pyruvate to minimal medium overcame or repaired this injury, the catalase system appeared to be the site of injury.
Nature of intracellular type A botulinum neurotoxin
Authors: Krysinski E P , Sugiyama H
Published: January 2020

The neurotoxin in cells of young Clostridium botulinum type A culture was extracted with lysozyme. Highly purified neurotoxin preparation, obtained by processing the extract in two chromatographic steps had only unnicked (single-chain) molecules of molecular weight comparable to that of the dichains isolated from type A crystals. Trypsinization converted the unnicked molecules into dichains whose component subunits were of sizes indistinguishable from those of the neurotoxin from crystals. The enzymatic treatment increased toxicity of crude extract 30-fold but did not activate the purified intracellular neurotoxin preparation. The results indicated that intracellular type A botulinum neurotoxin is unnicked, is not fully activated, and is activated in the time between its extraction and purification. Since trypsinization nicked all of the single chains without increasing toxicity, nicking was not causally related to toxicity activation.
Use of aflatoxin-producing ability medium to distinguish aflatoxin-producing strains of Aspergillus flavus
Authors: Wicklow D T , Shotwell O L , Adams G L
Published: January 2020

Aflatoxin-producing ability medium was tested for its ability to distinguish aflatoxin-positive from aflatoxin-negative strains of Aspergillus flavus in naturally occurring populations from corn at harvest. All of the aflatoxin-positive strains and some of the aflatoxin-negative strains produced aflatoxins when cultured on cracked corn. Although the data indicate that aflatoxin-producing ability medium is not entirely reliable in distinguishing potential aflatoxin-producing strains of A. flavus from nontoxigenic strains, it is significant that the medium did not yield false-positives.
Superoxide dismutase activity during recovery of thermally stressed Staphylococcus aureus MF-31
Authors: Bucker E R , Martin S E
Published: January 2020

Superoxide dismutase (SOD) activity was determined during the growth cycle of unheated and heat-injured cells of Staphylococcus aureus MF-31. SOd activity levels dropped in unheated cells during the lag phase, increased during logarithmic phase, and became constant in the stationary phase. Cells which were sublethally heated (52 degrees c, 20 min) in 100 mM phosphate buffer and subsequently allowed to recover in tryptic soy broth demonstrated an 85% decrease in SOD activity upon inoculation into recovery medium. As the injured cells repaired the heat-induced lesions and entered logarithmic growth, SOD levels rapidly increased. Heat-injured cells allowed to recover in tryptic soy broth plus 10% NaCl showed similar decreases in SOD activity levels. However, no subsequent increase was observed when specific activity was calculated based on milligrams of protein.
Isolation and characterization of thirteen intestinal microorganisms capable of 7 alpha-dehydroxylating bile acids
Authors: Hirano S , Nakama R , Tamaki M , Masuda N , Oda H
Published: January 2020

Thirteen anaerobic bacteria capable of performing the 7 alpha-dehydroxylation of both cholic acid and chenodeoxycholic acid were isolated from human feces and also from sewage. Ten organisms from heat-treated samples were species of Clostridium identical or closely related to the Clostridium bifermentans-C. sordellii group and consisted of four strains elaborating 7 alpha-dehydroxylase alone and six strains capable of catalyzing both 7 alpha-dehydrogenation and 7 alpha-dehydroxylation. The remaining three organisms, recovered from fresh human feces, were gram-positive, nonflagellated, nonsporeforming, anaerobic rods and comprised two distinct species. Strain HD-17, still unidentified, had both activities, but was unique in that it exclusively 7 alpha-dehydroxylated cholic acid while biotransforming chenodeoxycholic acid, preferably though 7 alpha-dehydrogenation. Two unclassified strains, b-8 and c-25, metabolized both acids though 7 alpha-dehydroxylation and 7 alpha-dehydrogenation. Except for strains b-8 and c-25, all of th 7 alpha-dehydroxylating bacteria split the conjugated bile acid series, and hydrolases were detected in cell-free filtrates of early stationary-phase broth cultures.
Problematic Occurrence of Tyrosine Crystals in the Thai Soybean Paste Tao Chieo
Authors: Flegel T. W. , Bhumiratana A. , Srisutipruti A.
Published: January 2020

In a Bangkok soy sauce factory that had recently converted to controlled inoculum and incubation for the koji stage of fermentation, a problem arose with unsightly white particles in the soybean paste condiment called tao chieo. This problem had not arisen during the previous history of the factory where the koji stage of the fermentation was uncontrolled. Microscopic examination of the particles showed that they were crystalline. Physical separation of the crystals followed by solvent extraction, recrystallization, chemical characterization, and spectroscopy showed that they consisted of tyrosine. Tao chieo prepared by using low- or high-protease strains of
Aspergillus
sp. indicated that the tyrosine crystals resulted from mold proteolysis of the soybean substrate. Addition of polyethylene glycol at the beginning of the moromi fermentation reduced the severity of crystal formation.
Surface Changes in Mild Steel Coupons from the Action of Corrosion-Causing Bacteria
Authors: Obuekwe Christian O. , Westlake Donald W. S. , Cook Fred D. , William Costerton J.
Published: January 2020

Changes which occur on the surface of mild steel coupons submerged in cultures of an Fe(III)-reducing bacterium, isolated from corroded pipe systems carrying crude oil, were studied microscopically to investigate the interaction between the corrosion-causing bacterium and the corroding mild steel coupon. Under micro-aerobic conditions and in the absence of the bacteria, a dense, crystalline, amorphous coat formed on the surface of the steel coupons. In the presence of bacteria the surface coat was extensively removed, exposing the bare metal to the environment. After about 2 weeks of exposure, the removal of the surface coating was followed by colonization of the metal surface by the bacteria. Colonization was mediated by fibrous, exopolysaccharidic material formed by the bacteria. Extension of studies to other bacteria isolated from crude oil and corroded pipes reveals that the formation of exopolysaccharide fibers and possession of adherent properties are common characteristics of bacteria from crude oil systems.
Calcium-Induced Alteration of Cellular Morphology Affecting the Resistance of
Lactobacillus acidophilus
to Freezing
Authors: Wright C. T. , Klaenhammer T. R.
Published: January 2020

Examination of factors affecting the resistance of
Lactobacillus acidophilus
NCFM culture concentrates to freeze injury induced during frozen storage at -20°C revealed that calcium supplementation of the growth medium contributed to the storage stability of cells prepared in static culture. Culture concentrates of
L. acidophilus
NCFM were prepared from cells propagated in MRS broth or MRS broth supplemented with 0.1% calcium carbonate, calcium chloride, or calcium phosphate. After 28 days of frozen storage at -20°C, concentrated cells (3.2 × 10
9
colony-forming units per ml) prepared from MRS broth cultures showed an 84% reduction in viable cells. Of the remaining viable cells, 88% were sublethally injured and unable to form colonies on MRS agar supplemented with 0.15% bile. Cells prepared in calcium-supplemented MRS broths demonstrated more resistance to frozen storage. Viability and injury losses in the frozen concentrates were limited to 10 to 39% and 3 to 23%, respectively. It was observed that calcium supplementation of MRS medium resulted in a morphological transition of
L. acidophilus
NCFM from filamentous to bacilloid rods, and the bacilloid cells were more resistant to freezing and storage at conventional freezer temperatures. The results suggest that the morphology of the
L. acidophilus
cell may be an important consideration in the preparation of freeze-stable culture concentrates.
Volatile Compounds Associated with Spoilage of Vacuum-Packaged Sliced Luncheon Meat by
Brochothrix thermosphacta
Authors: Stanley Gerald , Shaw Kevin J. , Egan Aubrey F.
Published: January 2020

By using gas chromatography-mass spectrometry, seven volatile compounds were identified in vacuum-packaged sliced corned beef spoiled by
Brochothrix thermosphacta
under aerobic conditions. Acetoin and diacetyl appeared to be of major sensory significance.
Simple filter paper procedure for estimation of glucose uptake via group translocation by whole-cell suspensions of bacteria
Authors: Germaine G R , Tellefson L M
Published: January 2020

A simple and rapid filter paper technique is described for processing samples from glucose uptake studies with whole cells of gram-positive or gram-negative bacteria that transport glucose via group translocation. The procedure yields results equivalent to those obtained with a conventional membrane filtration method and requires no special filtration equipment or source of vacuum.
Detection of Rotavirus in Sewage
Authors: Steinmann Jochen
Published: January 2020

For detection of rotavirus, domestic sewage was concentrated by two different methods: (i) adsorption to and elution from positively charged Seitz filters, followed by ultracentrifugation, and (ii) chemical precipitation. The concentrated fluids were tested by an enzyme-linked immunosorbent assay and electron microscopy. In 6 of 24 (25%) samples, rotavirus was detectable after the combined filtration and ultracentrifugation technique with both an enzyme-linked immunosorbent assay and electron microscopy. No positive results were obtained after chemical precipitation.
Serological Diversity of
Nitrobacter
spp. from Soil and Aquatic Habitats
Authors: Stanley P. M. , Schmidt E. L.
Published: January 2020

Serotypic diversity among
Nitrobacter
spp. isolates is greater than previously reported. Typing with fluorescent antibodies prepared against 11
Nitrobacter
spp. cultures isolated from soil and water placed the isolates into six serogroups. When these fluorescent antibodies were applied to a group of 16 additional isolates, 8 were identifiable by cross-reaction to 3 of the 11 fluorescent antibodies. Some nitrite-oxidizing enrichment cultures from different habitats contained cross-reacting strains of
Nitrobacter
spp.
Abnormal concentrations of B vitamins and amino acids in plasma and B vitamins in bile of rabbits with aflatoxicosis
Authors: Viogt M N , Clarke J D , Jain A V , Ayres J C , Koehler P E , Hatch R C
Published: January 2020

The dosages of aflatoxin B1 (AFB1) required to produce significant changes in concentrations of B vitamins in plasma and bile and of amino acids in plasma of rabbits were determined. Folate increased by 98% in plasma, whereas concentration of thiamine, vitamin B6, and biotin decreased by more than 50%. In bile, choline and biotin increased 14- and 18-fold, respectively, whereas folate and niacin decreased by more than 50%. All amino acids in plasma increased between 76 and 155%. The dosages of AFB1 required to induce these changes were usually between 12.5 and 37.5 microgram/kg of body weight per day. Except for changes in biliary concentrations of pantothenic acid, folic acid, and biotin, lower threshold dosages of aflatoxin were required to produce weight loss and anorexia (5.0 and 8.5 microgram of AFB1/kg per day, respectively) than for changes in vitamins and amino acids (approximately 25 to 50 microgram of AFB1/kg per day). The data indicated that AFB1 interfered with the metabolism of B vitamins and amino acids in rabbits.
Separation and Some Properties of Two Intracellular β-Glucosidases of
Sporotrichum (Chrysosporium) thermophile
Authors: Meyer Hans-Peter , Canevascini Giorgio
Published: January 2020

Intracellular, inducible β-glucosidase from the cellulolytic fungus
Sporotrichum (Chrysosporium) thermophile
(ATCC 42464) was fractionated by gel chromatography or isoelectric focusing into components A and B. Enzyme A (molecular weight 440,000) had only aryl-β-glucosidase activity, whereas enzyme B (molecular weight 40,000) hydrolyzed several β-glucosides but had only low activity against
o
-nitrophenyl-β-
d
-glucopyranoside (ONPG). Both enzymes had temperature optima of about 50°C. The pH optimum was 5.6 for enzyme A and 6.3 for enzyme B, respectively. The

K
m

(ONPG) value for enzyme A was 0.5 mM, and the corresponding values for enzyme B were 0.18 mM (ONPG) and 0.28 mM (cellobiose). Enzyme B, when tested with ONPG, showed substrate inhibition at a substrate concentration above 0.4 mM which could be released by cellobiitol and other alditols. Enzyme A was isoelectric at pH 4.48, and enzyme B was isoelectric at pH 4.64. Several inhibitors were tested for their action on the activity of enzymes A and B. Both enzymes were found to be concomitantly induced in cultures with either cellobiose or cellulose as carbon source.
R-Plasmid Transfer to and from
Escherichia coli
Strains Isolated from Human Fecal Samples
Authors: Corliss T. L. , Cohen P. S. , Cabelli V. J.
Published: January 2020

Strains of
Escherichia coli
recently isolated from human feces were examined for the frequency with which they accept an R factor (R1) from a derepressed fi
+
strain of
E. coli
K-12 and transfer it to fecal and laboratory strains. Colicins produced by some of the isolates rapidly killed the other half of the mating pair; therefore, conjugation was conducted by a membrane filtration procedure whereby this effect was minimized. The majority of fecal
E. coli
isolates accepted the R factor at lower frequencies than K-12 F
−
, varying from 10
−2
per donor cell to undetectable levels. The frequencies with which certain fecal recipients received the R-plasmid were increased when its R
+
transconjugant was either cured of the R1-plasmid and remated with the fi
+
strain or backcrossed into the parental strain. The former suggests the loss of an incompatibility plasmid, and the latter suggests the modification of the R1-plasmid deoxyribonucleic acid (DNA). In general, the fecal R
+
E. coli
transconjugants were less effective donors for K-12 F
−
and heterologous fecal strains than was the fi
+
K-12 strain, whereas the single strain of
Citrobacter freundii
examined was generally more competent. Passage of the R1-plasmid to strains of salmonellae reached mating frequencies of 10
−1
per donor cell when the recipient was a
Salmonella typhi
previously cured of its resident R-plasmid. However, two recently isolated strains of
Salmonella
accepted the R1-plasmid from
E. coli
K-12 R
+
or the R
+
E. coli
transconjugants at frequencies of 5 × 10
−7
or less.
Curvularia lunata
, a New Source of Cytochalasin B
Authors: Wells John M. , Cole R. J. , Cutler H. C. , Spalding D. H.
Published: January 2020

A biologically active metabolite was found in crude extracts of
Curvularia lunata
(Wakker) Boedijn (ATCC 34690) isolated from decayed tissues of litchi fruit (
Litchi chinensis
Sonn.). The fungus was grown on a shredded wheat-yeast extract-sucrose medium, and cultures were extracted with chloroform after 3 weeks of growth at 21°C. Chloroform extracts were toxic to day-old cockerels and caused abnormal distortion of wheat coleoptile segments. The major toxin had a 50% lethal dose of 700 mg/kg (oral dose) and was a colorless crystalline material with a melting point of 218°C. Elemental and high-resolution mass spectral analyses indicated a formula of C
29
H
37
NO
5
and a molecular weight of 479.62. The crystalline preparation was identified as 97% cytochalasin B and 3% cytochalasin A. The yield of cytochalasin B from
C. lunata
cultures grown on 4.5 kg of shredded wheat and 9 liters of yeast extract-sucrose medium was 6.24 g of purified material.
Inhibition of aflatoxin production by selected insecticides
Authors: Draughon F A , Ayres J C
Published: January 2020

The insecticide naled completed inhibition production of aflatoxins B1, B2, G1, and G2 by and growth of Aspergillus parasiticus at a 100-ppm (100 microgram/ml) concentration. The insecticides dichlorvos, Landrin, pyrethrum, Sevin, malathion, and Diazinon significantly (P = 0.05) inhibited production of aflatoxins at a 100-ppm concentration. However, at a concentration of 10 ppm, significant inhibition in production of aflatoxins was found only with naled, dichlorvos, Sevin, Landrin, and pyrethrum. Dichlorvos, Landrin, Sevin, and naled inhibited growth of A. parasiticus by 28.9 , 18.9, 15.7, and 100%, respectively, at 100 ppm. Stimulation of growth was observed when diazinon was added to cultures. Aflatoxin B1 was most resistant to inhibition by insecticides, followed by G1, G2, and B2, respectively.
Survival of Microorganisms in a Rock Bed Under Conditions Simulating Solar Heat Storage
Authors: Zervins Andris , Babcock Michael , Stone Robert W.
Published: January 2020

A laboratory-scale unit containing about 360 kg of washed river gravel was designed to [ill] the use of rocks for heat storage. The unit was operated under varying conditions of temperature, relative humidity, and the addition of volatile nutrients over a 4-month period. Effluent air and rock surfaces were monitored for the presence of microorganisms. After 2 weeks, virtually no microorganisms were detected in the effluent air except when dry soil or compost was added as the inoculum. A small number of heat-resistant bacteria, but no fungi, were found to survive on the rock surfaces. Microorganisms isolated were either sporeforming bacteria or actinomycetes closely resembling
Thermoactinomyces vulgaris.
Microbial colonization of rock beds used for solar heat storage does not appear likely under routine operation.
Effects of moisture content on long-term survival and regrowth of bacteria in wastewater sludge
Authors: Yeager J G , Ward R L
Published: January 2020

The effects of moisture content on the survival and regrowth of seeded and indigenous enteric bacteria in raw sludge were determined. Cultures of six strains of fecally associated bacteria grown in sterilized, liquid sludge (5% solids) were all quite stable at this moisture level for over 90 days at 21 degrees C. When the moisture content of the sludge containing these organisms was reduced by evaporation and the samples were stored at 21 degrees C for extended periods, bacterial inactivation rates were generally proportional to the moisture losses of the samples. A dramatic reversal in this effect was observed in samples containing more than 90% solids. In this dried sludge, every bacterial species studied except Proteus mirabilis was found to be extremely stable. Bacteria indigenous to sludge were also found to survive for long periods in dried sludge. Regrowth of bacterial isolates in sterilized raw sludge was found to occur readily at 37 degrees C in samples containing less than or equal to 75% solids, but no growth was observed in samples with greater than or equal to 85% solids. Some growth, but to less than saturation densities, occurred with 80% solids. Growth of seeded Salmonella typhimurium was also found to occur in the presence of indigenous organisms in both liquid and dewatered raw sludges. However, the population density attained was well below that found in sterilized samples of the same sludges. In addition, the number of salmonellae dropped below detectable limits within a few days in sludges containing viable indigenous organisms, whereas little decrease occurred during this time with salmonellae grown in previously sterilized sludges.
Comparison of Two Direct-Count Methods for Determining Metabolizing Bacteria in Freshwater
Authors: Maki James S. , Remsen Charles C.
Published: January 2020

Planktonic bacteria collected from several freshwater environments and cultured bacteria were used to compare two methods for determining the numbers of metabolizing bacteria. The methods used were (i) reduction of 2-(ρ-iodophenyl)-3-(ρ-nitrophenyl)-5-phenyl tetrazolium chloride 2-(ρ-iodophenyl)-3-(ρ-nitrophenyl)-5-phenyl to tetrazolium chloride-formazan and (ii) elongation of cells by using yeast extract and nalidixic acid. No statistically significant difference was found between methods in determining metabolizing bacteria, although significant differences (
P
< 0.05) were found when comparing numbers of total bacteria. A combination of the two methods yielded significant changes, both positive and negative, in the numbers of metabolizing bacteria.
Distribution of ribonucleic acid coliphages in raw sewage from treatment plants in Japan
Authors: Furuse K , Ando A , Osawa S , Watanabe I
Published: January 2020

To determine the transmission cycle of ribonucleic acid (RNA) coliphages in their natural habitats, we investigated the distribution patterns of RNA phages in raw sewage collected from treatment plants in various localities in Japan. Most of the sewage samples contained group II and III phages. Samples from treatment plants in Sapporo, Tokyo, and Toyama contained appreciable amounts of group I phages in addition to the group II and III phages. As a whole, raw sewage from treatment plants in Japan contained RNA phages of the three groups in the ratio 1:2:5, group I/II/III. Based on the distribution patterns of RNA phages in sewage from domestic drainage in Japan proper (group II/III, 3:1), in animal feces and sewage from slaughter houses (mostly group I), and in human feces (group II/III, 1:1), it can be reasonably said that group I phages tend to be introduced from animal sources and group II and III phages tend to be introduced from human sources. Raw sewage from treatment plants in Japan consists mainly of human feces, sewage from domestic drainage, and industrial wastewater, and, in part, from slaughter houses. In fact, sewage from slaughter houses together with that from human sources flowed into the treatment plants of Tokyo as far as we could confirm.
Physical Factors That Affect In Vitro
Autographa californica
Nuclear Polyhedrosis Virus Infection
Authors: Dougherty Edward M. , Weiner Ronald M. , Vaughn James L. , Reichelderfer Charles F.
Published: January 2020

Of the physical parameters tested for in vitro baculovirus infection, multiplicity of infection was most important in governing percent cell infection. Most plaques formed within the first 5 min of incubation. Efficiency of infection, however, was low, and the virus titer did not diminish during prolonged incubation. Efficiency of infection improved markedly when cells or virus were preincubated with selected polyanions and polycations. Precise regulation of the pH, osmotic pressure, and ionic composition of the cell culture medium also promoted maximum in vivo infection.
Relationship of sporulation, enterotoxin formation, and spoilage during growth of Clostridium perfringens type A in cooked chicken
Authors: Craven S E , Blankenship L C , McDonel J L
Published: January 2020

Sporulation and enterotoxin formation were determined for 17 strains of Clostridium perfringens type A in autoclaved chicken dark meat and in Duncan-Strong sporulation medium. The mean numbers of heat-resistant spores detected after 24 h at 37 degrees C were log10 1.13 to log10 7.64/ml in Duncan-Strong medium and log10 4.93 to log10 6.59/g in chicken. Of 17 strains, 7 formed enterotoxin in Duncan-Strong culture supernatant (1.0 to 60 microgram/ml) and 8 produced enterotoxin in chicken (0.21 to 24 microgram/g). Additional studies with chicken were conducted with C. perfringens NCTC 8239. With an inoculum of 10(6) cells per g, greater than log10 7.99 vegetative cells per g were detected by 4 h in chicken at 37 degrees C. Heat-resistant spores occurred by 4 and 6 h and enterotoxin occurred by 8 and 6 h in autoclaved chicken dark meat and barbecued chicken drumsticks, respectively. Enterotoxin was detected in autoclaved dark meat after incubation at 45 degrees C for 1.5 h followed by 37 degrees C for 4.5 h, but not after incubation at 45 degrees C for 1.5 to 8 h. With an inoculum of 10(2) cells per g in oven-cooked or autoclaved chicken, greater than log10 8.00 vegetative cells per g were detected by 6 to 8 h at 37 degrees C, heat-resistant spores were detected by 8 h, and enterotoxin was detected by 12 h. A statistical analysis of odor determinants of chicken after growth of C. perfringens indicated that, at the 95% confidence level, the product was considered spoiled (off or unwholesome odor) by the time spores or enterotoxin were formed.