bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Enteroviruses with Natural and Artificially Introduced Colloidal Solids in Water and Infectivity of Solids-Associated Virions
Authors: Schaub S. A. , Sagik B. P.
Published: December 2020

Encephalomyocarditis viruses adsorb to introduced organic and inorganic solids in water over a wide range of pH and with various concentrations and species of metal cations. Visible flocculation of solids was not a prerequisite for significant virus association. Virus adsorption to natural solids in various types of natural waters was significant but variable. Clay-adsorbed virus retained its infectivity in tissue culture monolayers. These solids-associated viruses also retained infectivity in mice.
Microbiological Hazards of Household Toilets: Droplet Production and the Fate of Residual Organisms
Authors: Gerba Charles P. , Wallis Craig , Melnick Joseph L.
Published: December 2020

Large numbers of bacteria and viruses when seeded into household toilets were shown to remain in the bowl after flushing, and even continual flushing could not remove a persistent fraction. This was found to be due to the adsorption of the organisms to the porcelain surfaces of the bowl, with gradual elution occurring after each flush. Droplets produced by flushing toilets were found to harbor both bacteria and viruses which had been seeded. The detection of bacteria and viruses falling out onto surfaces in bathrooms after flushing indicated that they remain airborne long enough to settle on surface throughout the bathroom. Thus, there is a possibility that a person may acquire an infection from an aerosol produced by a toilet.
Transformation of Morphine by Resting Cells and Cell-Free Systems of
Arthrobacter
Sp
Authors: Liras Paloma , Umbreit W. W.
Published: December 2020

Morphine can be transformed into 14-hydroxymorphine and a related unidentified material by resting cells of an
Arthrobacter
species. Cell-free extracts containing the transforming enzyme(s) have been obtained. O
2
, Fe
2+
, and reduced nicotinamide adenine dinucleotide stimulate the transformation.
Chemostat Culture of
Escherichia coli
K-12 Limited by the Activity of Alkaline Phosphatase
Authors: King Stagg L. , Francis J. C.
Published: December 2020

The growth-limiting reaction of a chemostat culture of
Escherichia coli
K-12 was the hydrolysis of β-glycerophosphate by alkaline phosphatase. The culture was buffered at pH 5.2 where alkaline phosphatase was unable to supply phosphate to the cell at a rate sufficient to sustain the maximum rate of growth. Alkaline phosphatase activity in this system is discussed in terms of the so-called Flip-Flop mechanism.
Studies on Thermophilic Cellulolytic Fungi
Authors: Romanelli R. A. , Houston C. W. , Barnett S. M.
Published: December 2020

Three thermophilic cellulolytic fungi,
Chaetomium thermophile
var.
coprophile, Sporotrichum thermophile
, and
Thermoascus aurantiacus
were studied to determine the conditions for a high rate of cellulose degradation. The range of temperature over which good growth occurred was determined first in a temperature gradient incubator; the optimum temperature was then established in shake flask cultures.
T. aurantiacus
had the highest optimum growth temperature range (46 to 51 C), whereas
S. thermophile
had the broadest range over which good growth occurred (36 to 43 C). Optimum temperatures for the three organisms,
T. aurantiacus, S. Thermophile
, and
C. thermophile
were 48, 40, and 40 C, respectively. It was found that the addition of an organic carbon and nitrogen source to a cellulose mineral solution medium markedly increased the rate of cellulose degradation. The surfactant, Tween 80, which has been reported to be of value in the production and recovery of the enzyme, cellulase, was shown to be detrimental to the degradation of cellulose in culture. In the medium used,
S. thermophile
gave the highest rate of substrate utilization; 56% of the cellulose was hydrolyzed in 72 h. The average degree of polymerization of cellulose decreased from 745 to 575.
Column Chromatography and Cell Culture Assay of
Pseudomonas aeruginosa
Toxin Z Preparations
Authors: Ludovici Peter P. , Roinestad Frank A. , Wong Francis S.
Published: December 2020

Toxic material produced by
Pseudomonas aeruginosa
in cell culture was concentrated and partially purified. This toxic material, designated toxin Z, was produced during the growth of strain PA Z or PA 103 in HEp-2 monolayer cultures using Eagle minimal essential medium with 10% serum. Toxin Z, concentrated fourfold by Lyphogel or ultrafiltration, was used to produce antiserum in rabbits and also was fractionated by column chromatography, Twentyfold purification of toxin Z was obtained on a Sephadex G-200 column. Toxic column fractions were confirmed to have toxin Z by neutralization with specific antiserum. During concentration, purification, and neutralization procedures, the toxin was assayed exclusively by the cytopathic effect it produced in cell culture.
Survival of Human Enteric and Other Sewage Microorganisms Under Simulated Deep-Sea Conditions
Authors: Baross John A. , Hanus F. Joe , Morita Richard Y.
Published: December 2020

The survival of pure cultures of
Escherichia coli, Streptococcus faecalis, Clostridium perfringens
, and
Vibrio parahaemolyticus
under simulated deep-sea conditions of low temperature (4 C), seawater, and hydrostatic pressures ranging from 1 to 1,000 atm was determined over a period exceeding 300 h. The viability of
E. coli
and total aerobic bacteria in seawater-diluted raw sewage subjected to these deep-sea conditions was also measured. There was a greater survival of both
E. coli
and
S. faecalis
at 250 and 500 atm than at 1 atm at 4 C.
S. faecalis
was quite insensitive to 1,000 atm, whereas with
E. coli
there was a 10-fold die-off per 50-h exposure to 1,000 atm. In contrast,
V. parahaemolyticus
and
C. perfringens
were quite sensitive to pressures exceeding 250 atm, and with both of these species there was a total loss of viability of approximately 10
8
cells per ml within 100 h at 1,000 atm and within 200 h at 500 atm. The viability of the naturally occurring fecal coliforms in sewage exposed to moderate pressures at 4 C was found to be similar to the survival patterns demonstrated with pure cultures of
E. coli
. The total numbers of aerobic bacteria in these sewage samples, however, stabilized at 500 and 1,000 atm after 100 h, and at 1 and 250 atm there was significant growth of sewage-associated bacteria, which apparently utilized the organic compounds in the seawater-diluted sewage samples. A preliminary classification of some of these bacteria indicated that approximately 90% (160 isolates) of the organisms that survived over a 400-h exposure to 500 and 1,000 atm were
Arthrobacter/Corynebacterium
species, and the representative organisms capable of growing at 1 and 250 atm in seawater at 4 C were gram-positive cellulose digesters and an unidentified gram-negative coccus. The significance of these results with respect to the contamination of the deep ocean with human pathogens and the possibility of sewage-associated microorganisms growing and competing with indigenous marine microbial flora in situ is discussed.
Reduction of Endotoxin Levels in Influenza Virus Vaccines by Barium Sulfate Adsorption-Elution
Authors: Reichelderfer Patricia S. , Manischewitz Jody F. , Wells Martha A. , Hochstein Herbert D. , Ennis Francis A.
Published: December 2020

The level of endotoxin in influenza virus vaccine lots was reduced 10- to 20-fold after barium sulfate adsorption-elution. The amount of viral antigen lost was negligible.
Metalloprotease from
Bacillus thuringiensis
Authors: Li Eugenia , Yousten Allan A.
Published: December 2020

Bacillus thuringiensis
var.
kurstaki
was shown to produce an extracellular, metal chelator-sensitive protease during the early stages of sporulation. Protease production in nutrient broth was dependent upon supplementation with Mn
2+
or Ca
2+
. The addition of Ca
2+
was required for enzyme stabilization. Protease production occurred in nutrient broth supplemented with 7 � 10
-3
M Ca
2+
, 5 � 10
-4
M Mn
2+
, and 10
-3
M Mg
2+
. The protease had optimum activity in the pH range 6.5 to 7.5. It was inhibited by chelating agents but not by a serine protease inhibitor. The culture supernatant and the partially purified protease lacked esterase activity. Partial purification of the enzyme (92.3 �) by (NH
4
)
2
SO
4
fractionation and starch adsorption yielded an enzyme whose molecular weight was estimated to be 37,500 by acrylamide gel-sodium dodecyl sulfate electrophoresis or 40,800 by sucrose density gradient centrifugation. In the presence of Ca
2+
, the partially purified enzyme retained 78% of its activity after heating at 70 C for 10 min but only 8% of its activity after heating at 80 C for 10 min.
Amino Acid Requirements and Proteolytic Activity of
Streptococcus sanguis
Authors: Cowman R. A. , Perrella M. M. , Adams B. O. , Fitzgerald R. J.
Published: December 2020

The growth response of
Streptococcus sanguis
groups 1:A and 1:B in a complete chemically defined medium was not influenced by the oxygen concentration of the growth atmosphere. All of the cultures required cysteine and arginine; tyrosine and branched-chain amino acids were frequently required. Proteolysis of casein, mucin, and the anionic proteins of germfree rat saliva by
S. sanguis
was demonstrated. Hydrolytic activity toward casein was found in the soluble contents of the cells and in the cellular debris after disruption of the cells, with the soluble fractions exhibiting greater proteolytic activity toward casein. The soluble fractions from
S. sanguis
did not hydrolyze mucin, but this substrate was hydrolyzed by the cell debris fraction. When the amino acid requirements and proteolytic activity of
S. sanguis
and
S. mutans
were compared, these two oral streptococcal species exhibited distinct and characteristic differences.
Distribution and Persistence of
Staphylococcus
and
Micrococcus
Species and Other Aerobic Bacteria on Human Skin
Authors: Kloos Wesley E. , Musselwhite Margaret S.
Published: December 2020

The distribution of
Staphylococcus
and
Micrococcus
species and associated coryneform bacteria,
Acinetobacter, Klebsiella, Enterobacter, Bacillus
, and
Streptomyces
on skin was determined during October 1971 from samples collected on persons living in North Carolina and New Jersey. Persistence of these organisms on skin was estimated in temporal studies conducted during the period from June 1971 to June 1972 on persons living in North Carolina. Staphylococci and coryneforms were the most predominant and persistent bacteria isolated from the nares and axillae. Staphylococci, coryneforms, micrococci, and
Bacillus
were the most predominant and persistent bacteria isolated from the head, legs, and arms. Acinetobacters were most frequently isolated during the warmer months of the years.
Staphylococcus aureus
and
S. epidermidis
were the most predominant and persistent staphylococci isolated from the nares, whereas
S. epidermidis
and
S. hominis
were the most predominant and persistent staphylococci isolated from the axillae, head, legs, and arms.
S. capitis
was often isolated from the head and arms and
S. haemolyticus
was often isolated from the head, legs, and arms.
S. simulans, S. xylosus, S. cohnii, S. saprophyticus, S. warneri
, and an unclassified coagulase-positive species were only occasionally isolated from skin.
Micrococcus luteus
was the most predominant and persistent
Micrococcus
isolated from skin and preferred regions of the head, legs, and arms.
M. varians
was the second most frequent
Micrococcus
isolated.
M. lylae, M. sedentarius, M. roseus, M. kristinae
, and
M. nishinomiyaensis
were only occasionally isolated from skin.
M. lylae
was most frequently isolated during the colder months of the years.
Effects of an Abrupt Change in Ration from All Roughage to High Concentrate upon Rumen Microbial Numbers in Sheep
Authors: Grubb Jean A. , Dehority B. A.
Published: December 2020

When three sheep were abruptly changed from a ration of 100% orchardgrass hay to 60% cracked corn-40% orchardgrass hay, fed at equal dry-matter intakes, significant increases in concentration were observed in the rumen microbial population. Bacterial numbers (colony counts) per gram of rumen contents did not appear to have stabilized within 21 days after the ration change; however, protozoan numbers per milliliter plateaued after 5 days. The concentration of cellulose-digesting bacteria varied considerably between animals and decreased in all animals with the change. Changes were observed in total and molar percentages of volatile fatty acids, which were typical for the two types of rations. Although the concentration of protozoa increased after the ration change, only minor differences were observed in their percent generic distribution. A significant decrease in rumen volume was measured in two of the three sheep with the change in ration; however, fluid turnover rates were not significantly affected. Rates of rumen dry-matter turnover were slower with the concentrate ration, although rumen dry-matter digestion was increased. Calculation of total bacterial numbers based on total rumen volume completely negated the effect of ration change in one animal, whereas total numbers in the other two animals were still significantly different between rations and very similar between animals. Adjustment of total protozoa numbers did not alter the trends seen previously with concentration values.
Adaptation of BHK-21 Cells to Growth in Shaker Culture and Subsequent Challenge by Japanese Encephalitis Virus
Authors: Guskey Louis E. , Jenkin Howard M.
Published: December 2020

Baby hamster kidney (BHK-21) cells were adapted to grow in shaker culture using Waymouth medium 752/1 containing 20 mM
N
-2-hydroxyethyl-piperazine-N′-2′-ethanesulfonic acid buffer and supplemented with 2.5% (vol/vol) calf serum, 0.002% (wt/vol) sodium oleate, and 0.2% fatty acid-free bovine serum albumin (WO
2.5
). Infectivity of Japanese encephalitis virus grown in the cells adapted to WO
2.5
approached 2 � 10
8
plaque-forming units per ml. The culture volume of infected cells was reduced fivefold 12 h after infection. This step resulted in a 10-fold increase in infectivity over that obtained from infected cultures not subjected to volume reduction.
Degradation of 3-Hydroxybenzoate by Bacteria of the Genus
Bacillus
Authors: Crawford Ronald L.
Published: December 2020

The pathway whereby certain bacterial strains of the genus
Bacillus
degrade
m
-hydroxybenzoate is delineated. Of 12 strains examined, nine were tentatively classified as representatives of the species
Bacillus brevis
, two of
Bacillus sphaericus
and one of
Bacillus megaterium
. All strains degraded
m
-hydroxybenzoate via the same pathway.
m
-Hydroxybenzoate was hydroxylated to 2,5-dihydroxybenzoate (gentisate), which was oxidized by a gentisate 1,2-dioxygenase yielding maleylpyruvate. Maleylpyruvate was hydrolyzed without prior
cis, cis
to
cis, trans
isomerization yielding pyruvate and maleic acid. Numerous soils were examined by plate-count procedures and found to contain 10
4
to 10
6
aerobic sporeformers able to grow on
m
-hydroxybenzoate per g of dry soil.
Characteristics of Heavily Mucoid Bacterial Isolated from Fish Pen Slime
Authors: Chai T. J. , Levin R. E.
Published: December 2020

Weakly gram-positive pleomorphic rods isolated from the slime on the storage pen surfaces of fishing trawlers were found to produce extensive capsular material and intensely mucoid colonies. The isolates studied produced highly pleomorphic club-shaped cells indicative of coryneforms. Their DNA base composition ranged from 64.2 to 68.2 mol% guanine plus cytosine on the basis of melting point determinations.

Images
Separation of Viable
Rickettsia typhi
from Yolk Sac and L Cell Host Components by Renografin Density Gradient Centrifugation
Authors: Weiss E. , Coolbaugh J. C. , Williams J. C.
Published: December 2020

Rickettsia typhi
cultivated in the yolk sac of chicken embryos or in L cells irradiated 7 days previously was separated from host cell components by two cycles of Renografin density gradient centrifugation. Preliminary steps involved differential centrifugation and centrifugation over a layer of 10% bovine plasma albumin of infected yolk sac suspensions, or trypsinization and passage through filters of wide porosity of infected L cell suspensions. Rickettsial preparations obtained by these methods appeared to be free from host cell components while retaining high levels of hemolytic activity, egg infectivity, and capacity to catabolize glutamate. Average yields were 3.3 mg of rickettsial protein per yolk sac or 0.44 mg per 16-oz (ca. 475-ml) L cell culture. Extracts from these two preparations displayed malate dehydrogenase activity of electrophoretic mobility identical to each other but quite different in migration patterns from the corresponding host cell enzymes. This method of separation of rickettsiae from host cell constituents appears to be particularly well suited for the study of rickettsial enzymatic activity.
Detection of Animal Viruses in Coastal Seawater and Sediments
Authors: De Flora Silvio , De Renzi Giuseppe P. , Badolati Giuseppe
Published: December 2020

Animal viruses, predominantly enteroviruses, were detected in shallow waters at bottom depths and in clastic marine sediments. Viruses accumulated in sandy and slimy deposits of the sea bottom near the shore and could be easily released into water by means of simple mechanical shaking.
Vitamin B
12
Production by a Methanol-Utilizing Bacterium
Authors: Toraya Tetsuo , Yongsmith Busaba , Tanaka Atsuo , Fukui Saburo
Published: December 2020

Vitamin B
12
production by a newly isolated strain of a methanol-utilizing bacterium was studied. The maximal yield of the vitamin, 2.6 mg/liter of medium was attained by optimization.
The Effects of Volatile Compounds from Nematodes on Trap Formation by a Nematode-Trapping Fungus
Authors: Schenck Susan , Pramer David
Published: December 2020

Although the presence of prey induced trap formation by nematode-trapping fungi, it is improbable that the activity was associated with volatile compounds of nematode origin.
Solid-Phase Radioimmunoassays for Quantitative Antibody Determination of
Clostridium perfringens
Type D ε Toxin
Authors: Bernáth S.
Published: December 2020

Two reversed solid-phase radioimmunoassays were developed for quantitative determination of antibodies against
Clostridium perfringens
type D ε toxin.
125
I-labeled prototoxin was used in the bromoacetylcellulose-bound antibody method and in the antibody-coated tube method. The antibody values which can be detected by the assays are in the range of 0.004 IU/ml of investigated serum. The methods allow the screening investigation of large groups of vaccinated sheep in a rapid and inexpensive way, and are very suitable for measuring small amounts of
C. perfringens
D ε antibodies with a small experimental error.
Convenient Non-Chromatographic Assays for the Microbial Deconjugation and 7α-OH Bioconversion of Taurocholate
Authors: Macdonald I. A. , Bishop J. M. , Mahony D. E. , Williams C. N.
Published: December 2020

We described two convenient assay methods to estimate bile acid deconjugation and bile acid bioconversion at the 7α-OH position by individual microorganisms grown in media containing taurocholic acid. The methods are based on (i) a selective chemical assay for taurine conjugates previously described and (ii) the use of a cell-free preparation of 7α-hydroxysteroid dehydrogenase from
Escherichia coli
to directly quantify 7α-OH groups. These non-chromatographic approaches have been applied to the study of three model strains of intestinal organisms,
E. coli, Bacteriodes fragilis
, and
Clostridium perfringens
, grown in standard media in the presence of purified tritiated taurocholate. Assay results were confirmed by thin-layer chromatography solvent systems designed to separate conjugated from unconjugated bile acid and unmodified cholic acid nucleus from 7α-OH bioconversion product(s) (primarily 3α,12α dihydroxy, 7-keto-cholanoic acid). In addition, 7α-hydroxysteroid dehydrogenase activity was demonstrated in cell-free extracts of all three organisms. Of the three organisms, only
C. perfringens
was demonstrated to (i) deconjugate taurocholic acid, (ii) contain 3α-hydroxysteroid dehydrogenase activity, (iii) convert cholic acid into at least five labeled metabolites visible on thin-layer chromatography, and (iv) catalyze significant tritium exchange with water in the medium.
Studies on the Survival and Fate of Enteroviruses in an Experimental Model of a Municipal Solid Waste Landfill and Leachate
Authors: Sobsey Mark D. , Wallis Craig , Melnick Joseph L.
Published: December 2020

In laboratory scale municipal solid waste lysimeters containing simulated refuse, and seeded with either laboratory or field strains of poliovirus type 1 and echovirus type 7, viruses were not detected in the lysimeter leachate produced over a 4-month period. In addition, viruses were not detected in the lysimeter refuse contents after termination of lysimeter operation. These results appeared to be due to virus retention in the lysimeter caused by virus adsorption and virus inactivation. Evidence for virus inactivation was provided by the results of experiments on virus inactivation in composite leachate samples. Evidence for virus adsorption was supported by the rapid adsorption of viruses to various municipal solid waste components in the presence of a salt solution similar in composition to the major inorganic salts of leachates.
Microbial Metabolism of a Parathion-Xylene Pesticide Formulation
Authors: Munnecke Douglas M. , Hsieh D. P. H.
Published: December 2020

A mixed bacterial culture was adapted to growth on a mixed carbon substrate consisting of the pesticide parathion and its xylene-based formulation. The environmental growth parameters of temperature, pH, and dissolved oxygen concentration were optimized to obtain complete metabolism of parathion from this mixed carbon substrate. This adapted culture grew rapidly (μ = 0.7 per h) on the pesticide formulation at high parathion suspensions (3,000 mg/liter). Carbon utilization from this mixed substrate was strongly dependent on pH. At slightly acidic pH, xylene was preferentially metabolized, whereas at slightly alkaline pH, parathion was preferentially metabolized. Diethylthiophosphoric acid, a metabolite from parathion, and toluic acid, a metabolite from xylene, also influenced the selection of the primary carbon source.
Production of Aflatoxins B
1
and G
1
by
Aspergillus flavus
and
Aspergillus parasiticus
Isolated from Market Pecans
Authors: Koehler P. E. , Hanlin R. T. , Beraha L.
Published: December 2020

One hundred and forty-eight isolates of
Aspergillus flavus
and
A. parasiticus
were isolated from 5,608 pecans obtained from Chicago and Georgia markets. The percentage of internal contamination by these species was 7.3% in the Chicago market pecans and 1.7% in those from markets in Georgia. Of the 148 isolates, 93% of the
A. parasiticus
, but only 54% of the
A. flavus
, were capable of producing aflatoxin. Overall, 57% of the isolates were potentially aflatoxigenic.
A. parasiticus
isolates generally produced a greater amount of aflatoxins than
A. flavus
.
Gas Chromatographic Presumptive Test for Coliform Bacteria in Water
Authors: Newman Judith S. , O'Brien R. T.
Published: December 2020

A gas chromatographic procedure which shows promise as a presumptive test for coliform bacteria in water is described. Total coliform bacteria concentrations were determined from the incubation times at 37 C required for ethanol to be produced. Fecal coliform densities were determined in a similar manner at 44.5 C. The culture medium was filter sterilized M-9 salts supplemented with 1% lactose, 0.1% Casamino Acids, and 0.1% yeast extract. Best results were obtained when the initial total coliform concentrations were 5 per ml or higher and when fecal coliform concentrations were 50 per ml or higher. Minimum detection times at these concentrations were 9 and 12 h, respectively.
Evaluation of a Most-Probable-Number Technique for the Enumeration of
Pseudomonas aeruginosa
Authors: Highsmith Anita K. , Abshire Robert L.
Published: December 2020

A most-probable-number (MPN) technique was evaluated for detecting and enumerating
Pseudomonas aeruginosa
in water and wastewater. Both the presumptive and confirmatory media, as described in the 13th edition of
Standard Methods for the Examination of Water and Wastewater
, as well as modifications of these media were included in evaluations. Various samples of water were tested, namely chlorinated tap water, creek water, and influent to a wastewater treatment plant. Modified media repeatedly gave higher estimated MPNs of
P. aeruginosa
than media listed in
Standard Methods. P. aeruginosa
was detected and recovered from all creek water and wastewater samples, but not from tap water samples tested. This organism was determined to be present in as large numbers as the fecal coliforms and in even greater quantities than the fecal streptococci in all samples, whenever MPN estimations were determined from those positive tubes containing the modified confirmatory medium.
Distribution and Significance of Fecal Indicator Organisms in the Upper Chesapeake Bay
Authors: Sayler G. S. , Nelson J. D. , Justice A. , Colwell R. R.
Published: December 2020

Total viable aerobic, heterotrophic bacteria, total coliforms, fecal coliforms, and fecal streptococci were enumerated in samples collected at five stations located in the Upper Chesapeake Bay, December 1973 through December 1974. Significant levels of pollution indicator organisms were detected at all of the stations sampled. Highest counts were observed in samples collected at the confluence of the Susquehanna River and the Chesapeake Bay. The indicator organisms examined were observed to be quantitatively distributed independently of temperature and salinity. Counts were not found to be correlated with concentration of suspended sediment. However, significant proportions of both the total viable bacteria (53%) and fecal indicator organisms (>80%) were directly associated with suspended sediments. Correlation coefficients (
r
) for the indicator organisms examined in this study ranged from
r
= 0.80 to
r
= 0.99 for bottom water and suspended sediment, respectively. Prolonged survival of fecal streptococci in most of the sediment samples was observed, with concomitant reduction of the correlation coefficient from
r
= 0.99, fecal streptococci to total coliforms in water, to
r
= 0.01, fecal streptococci to fecal coliforms in sediments. The results of this study compared favorably with fecal coliforms: fecal streptococci ratios for the various sample types. Characterization of organisms beyond the confirmed most-probable-number procedure provided good correlation between bacterial indicator groups.
Factors Affecting the Contribution by Epiphytic Algae to the Primary Productivity of an Oligotrophic Freshwater Lake
Authors: Sheldon Richard B. , Boylen Charles W.
Published: December 2020

A diatom-dominated population of epiphytic algae was studied in an oligotrophic lake to determine the factors which limit epiphyte growth and to measure their contribution to primary productivity. Algae were collected from plants growing at four sites in Lake George, N.Y., during the spring, summer, and fall of 1974. Samples were taken from 3 m, corresponding to the depth at which macrophytes were most productive. Algae exhibited an optimum temperature for H
14
CO
3
-
uptake at 30 C, although the summer littoral lake temperature ranged from 18 to 25 C. Light saturation occurred at an intensity of 8,608 lux, approximating the environmental intensity at the depth from which algae were taken. Epiphytes exhibited their maximum photosynthetic capacity of 0.6 mg of carbon fixed/m
2
of macrophyte surface area per h in the early afternoon in mid-August. They assimilated approximately 5% as much inorganic carbon as the macrophytes from which they were taken. Epiphyte population densities followed the seasonal growth patterns of the macrophytes, with maximal leaf colonization remaining essentially constant relative to the leaf position on the plant. There was little change in density between sampling sites at any given time. Productivities of epiphytes from bottom leaves were 10-fold greater than those of epiphytes from top leaves. Addition of PO
4
-3
, NO
3
-
, NH
3
, Si, and SO
4
-2
had no stimulatory effect on photosynthesis. Addition of HCO
3
-
stimulated photosynthesis greater than 30%, suggesting that carbon may be a limiting nutrient for epiphytic algae in Lake George.
Scanning Electron Microscope Study of Bacteria Associated with the Rumen Epithelium of Sheep
Authors: Bauchop T. , Clarke R. T. J. , Newhook J. C.
Published: December 2020

Examination of the rumen epithelium of sheep by scanning electron microscopy revealed bacteria associated with the epithelial surface. Comparison of epithelial surfaces from 10 sheep revealed areas that were consistently densely covered with bacteria and other areas where the cover was consistently light. The bacterial populations were frequently of mixed morphological types, but areas populated with a single type were also observed. This finding, together with the discovery of bacterial forms not previously described in rumen contents, suggests that a specific flora may exist on the rumen epithelial surface. The functional significance of such a population is discussed.
Comparison of the New Millipore HC with Conventional Membrane Filters for the Enumeration of Fecal Coliform Bacteria
Authors: Green Barbara L. , Clausen Elizabeth , Litsky Warren
Published: December 2020

Fecal coliform recoveries were determined for six types of membrane filters using 65 nonchlorinated water samples. Results showed that the membranes could be ranked in order of decreasing recovery as follows: Millipore HC > Gelman > Johns-Manville ∼ Sartorius > Millipore HA > Schleicher & Schuell.
Staphylococcal Enterotoxin C: Solid-Phase Radioimmunoassay
Authors: Bukovic Joann A. , Johnson Howard M.
Published: December 2020

A solid-phase radioimmunoassay test employing
125
I-labeled enterotoxin C and polystyrene tubes coated with specific antibody was used for the detection and quantitation of enterotoxin C in condensed milk, cheddar cheese, custard, and ham salad. The assay was sensitive to 1 to 10 ng of toxin per g of food; nonspecific inhibitions were 16% or less.
Bacteriological Evaluation of an Ultra-Pure Water-Distilling System
Authors: Kayser W. V. , Hickman K. C. D. , Bond W. W. , Favero M. S. , Carson L. A.
Published: December 2020

A prototype distillation and storage system with recycle for producing ultrapure water was monitored for bacteriological contamination during a period of 24 months. Naturally occurring
Pseudomonas aeruginosa
and
P. cepacia
were found to grow rapidly to levels of about 10
5
/ml in water taken from the storage reservoir and also in commercially prepared distilled water. The system was found to eliminate bacterial contaminants introduced into the still with the feed water, but the reservoir, once contaminated, remained contaminated during prolonged recycle. After a single treatment with free chlorine, the entire system remained uncontaminated until accidental or purposeful shutdown.
Comparison of Methods for Extraction of Bacterial Adenine Nucleotides Determined by Firefly Assay
Authors: Lundin Arne , Thore Anders
Published: December 2020

Adenine nucleotides in
Escherichia coli, Bacillus cereus, Klebsiella pneumoniae, Staphylococcus aureus
, and
Pseudomonas aeruginosa
were extracted using 10 different methods. Extracts were assayed for adenosine 5′-triphosphate (ATP), adenosine 5′-diphosphate (ADP), and adenosine 5′-monophosphate (AMP) by the firefly method using an improved procedure. Analytical interference by bacterial enzymes not inactivated during the extraction was found to be a major problem. However, these enzymes were inactivated to a considerable extent by the inclusion of ethylenediaminetetraacetate in the extraction reagent. The 10 extraction methods were compared with respect to yield of adenine nucleotides, interference with the enzymic assay, reproducibility of the method, and stability of the extracts. Results indicated that extraction with trichloroacetic acid was the method most closely reflecting actual levels of ATP, ADP, and AMP in intact bacterial cells. However, for the extraction of ATP in some bacterial strains several other methods may be used and may be advantageous from a practical point of view.
Dual Channel Temperature Recorder
Authors: Eisler William J. , LeBuis Donald A.
Published: December 2020

A dual channel temperature recorder is described which can measure temperatures linearly over a range of 0 to 80 C. The sensitivity can be adjusted so that any temperature span, as small as 3�, will cover recorder full scale, and temperatures can be read to 0.1�. The recorder provides two independent, permanent records of temperature variations which can be related directly to the time of day.
D-Glucose Isomerase: Constitutive and Catabolite Repression-Resistant Mutants of
Streptomyces phaeochromogenes
Authors: Sanchez Sergio , Quinto Carmen M.
Published: December 2020

As in other
Streptomyces
species, the enzymatic conversion of D-glucose to D-fructose is carried out in
Streptomyces phaeochromogenes
NRRL B-3559 by the inducible enzyme, D-xylose keto isomerase (EC 5.3.1.5.). Mutants of this microorganism were selected for their ability to grow on D-lyxose (2-epimer of D-xylose). As a result of the mutational event, the microorganism constitutively produced D-xylose isomerase. As in the parent strain, the constitutive formation of the isomerase was repressed by D-glucose. The fact that this mutant was unable to grow in low D-xylose concentrations in the presence of the D-glucose analogue, 3-
O
-methylglucose, permitted the isolation of D-xylose isomerase constitutive mutants which were insensitive to D-glucose repression.
Seasonal Occurrence and Distribution of Microbial Indicators and Pathogens in the Rhode River of Chesapeake Bay
Authors: Carney J. F. , Carty C. E. , Colwell R. R.
Published: December 2020

The seasonal incidence and occurrence of indicator organisms and pathogens were studied at four sites in the Rhode River, a subestuary of Chesapeake Bay. The highest frequency of occurrence of total and fecal coliforms and fecal streptococci was in Muddy Creek, a marsh area receiving pasture land runoff. Second highest frequency of occurrence of these bacteria was in Cadle Creek, a populated area. Lowest measurements of these parameters were obtained at stations in the central portion of the Rhode River. No
Salmonella
spp. were detected by the methods employed in this study. However, it is concluded that if these organisms are present, the concentrations are ≤1 organism per liter. The presence of
Clostridium botulinum
was detected in 12% of the samples tested.
Differential Effects of Oxygen and Oxidation Reduction Potential on the Multiplication of Three Species of Anaerobic Intestinal Bacteria
Authors: Walden William C. , Hentges David J.
Published: December 2020

The sensitivity of three strains of anaerobic intestinal bacteria,
Clostridium perfringens, Bacteroides fragilis
, and
Peptococcus magnus
, to the differential effects of oxygen and adverse oxidation-reduction potential was measured. The multiplication of the three organisms was inhibited in the presence of oxygen whether the medium was at a negative oxidation-reduction potential (Eh of -50 mV), poised by the intermittent addition of dithiothreitol, or at a positive oxidation-reduction potential (Eh of near +500 mV). However, when these organisms were cultured in the absence of oxygen, no inhibition was observed, even when the oxidation-reduction potential was maintained at an average Eh of +325 mV by the addition of potassium ferricyanide. When the cultures were aerated, the growth patterns of the three organisms demonstrated different sensitivities to oxygen.
P. magnus
was found to be the most sensitive. After 2 h of aerobic incubation, no viable organisms could be detected.
B. fragilis
was intermediately sensitive to oxygen with no viable organisms detected after 5 h of aerobic incubation.
C. perfringens
was the least sensitive. Under conditions of aerobic incubation, viable organisms survived for 10 h. During the experiments with
Clostridium
, no spores were observed by spore staining.
Effect of Physical Parameters on the In Situ Survival of
Escherichia coli
MC-6 in an Estuarine Environment
Authors: Faust Maria A. , Aotaky A. E. , Hargadon M. T.
Published: December 2020

Survival of
Escherichia coli
MC-6 of fecal origin in an estuarine environment as affected by time, water temperature, dissolved oxygen, salinity, and montmorillonite in diffusion chambers has been elucidated. Several in situ physical parameters were recorded simultaneously, and viable cell numbers were estimated. The survival of the bacteria varied seasonally. Montmorillonite addition extended the time needed for a 50% reduction of the viable cell population (
t
�
) of cells by 40% over the
t
�
of cells in Rhode River water alone. The effect of this clay was not significantly greater between 50- to 1,000-μg/ml montmorillonite concentrations. In all experiments, the relationships among pairs of variables were studied by regression and correlation analysis. The slope between viable cell numbers and water temperatures increased about 50% for each 10 C increment in temperature and gave a correlation coefficient
r
= 0.617, significant at 95% confidence level. A similar correlation coefficient,
r
= 0.670, was obtained between water temperature and
t
�
of the initial cell population. In all experiments regressions were performed considering all variables after bacteria had been in the Rhode River environment for 3 days. Coefficient of multiple determinaton was estimated as
R
2
= 0.756. Approximately 75.6% of the variance of viable cell numbers can be explained by variation in water temperature, dissolved oxygen, and salinity. Simple correlation coefficients within the regression steps were also computed. Survival of bacteria was closely and negatively correlated with increasing water temperature (
r
= -0.717). It is suggested that water temperature is the most important factor in predicting fecal coliform survival from point and nonpoint sources in assessing water quality in an estuarine ecosystem.
Identification of a Component of Crystalline Egg Albumin Bactericidal for Thermophilic Aerobic Sporeformers
Authors: Ashton D. H. , Wilson A. A. , Evancho G. M.
Published: December 2020

During an investigation of the effect of basic and acidic proteins on the growth of thermophilic aerobic sporeformers, crystalline egg albumin was found to be strongly bactericidal. This finding was uncharacteristic of acidic proteins. The bactericidal fraction was heat sensitive and separated from the non-bactericidal albumin fraction during gel filtration on Sephadex G-75. Cells of
Micrococcus lysodeikticus
and
Bacillus stearothermophilus
were lysed rapidly by the bactericidal component, leading to its tentative identification as lysozyme. The bactericidal substance possessed an electrophoretic mobility on polyacrylamide gel containing sodium dodecyl sulfate identical to that of crystalline egg white lysozyme. Users of crystalline egg albumin are cautioned that commercial preparations may be contaminated with lysozyme. Destruction of the thermophilic aerobes by lysozyme should be considered when performing counts on egg products.
Characterization of an Extracellular Dextranase from
Fusarium moniliforme
Authors: Simonson Lloyd G. , Liberta Anthony E. , Richardson Arlan
Published: December 2020

An extracellular dextranase (EC 3.2.1.11) was purified approximately 75-fold from cell-free culture filtrates of
Fusarium moniliforme
. The purified dextranase was of the endo type, and isomaltose was identified as the primary end product of dextran hydrolysis. The molecular weight of the dextranase was determined to be 39,000 by gel permeation chromatography. The enzyme was most active at pH 5.5, and the temperature optimum was near 55 C. Activity was not inhibited by either ethylenediaminetetraacetic acid or iodoacetate. The

K
m

for dextran with an average molecular weight of 10,000 was estimated to be 1.1 � 10
-4
M. The electrophoretic mobility of the dextranase was distinctly different from that of a
Penicillium
-derived commercial dextranase. The
F. moniliforme
dextranase was also found to differ from the commercial preparation by its greater relative activity against glucans isolated from
Streptococcus mutans
.
Repair of Heat-Injured
Clostridium
perfringes During Outgrowth
Authors: Barach J. T. , Flowers R. S. , Adams D. M.
Published: December 2020

Clostridium perfringens
strain NCTC 8798 spores were injured by ultrahigh temperature treatment and were unable to outgrow in the presence of antibiotics used in selective enumeration media. Injured spores underwent repair in a nonselective laboratory medium and in foods.
Fibrous Material in Feedlot Waste Fermented by
Trichoderma viride
Authors: Kaneshiro T. , Kelson B. F. , Sloneker J. H.
Published: December 2020

Trichoderma viride
QM9123 fermented fiber isolated from feedlot waste at concentrations up to 16.7% solids. The fermented fiber solids decreased by 32%, and carbohydrate decreased by 60%. Cellulolytic enzyme production was better with fiber substrates that had been alkali pretreated and had a lower hemicellulose-to-cellulose ratio.
Evaluation of petroleum-degrading potential of bacteria from water and sediment
Authors: Walker J D , Colwell R R , Petrakis L
Published: December 2020

Bacteria from water and sediment of an oil-polluted harbor were examined for ability to degrade petroleum. Water samples contained a greater variety of bacterial species capable of degrading petroleum than sediment. Cultures from both water and sediment contained Pseudomonas and Acinetobacter spp. Bacteria present in the water samples produced significantly greater degradation of 2-,3-,4-, and 5-ring cycloalkanes and mono-, di-, tri-, tetra-, and pentaaromatics compared with bacteria in sediment samples.
Microbial Inhibition by an Isolate of
Pediococcus
from Cucumber Brines
Authors: Fleming H. P. , Etchells J. L. , Costilow R. N.
Published: December 2020

We reported earlier that
Pediococcus cerevisiae
FBB-61 inhibited
Lactobacillus plantarum
FBB-67 in mixed species inoculation used for the fermentation of brined cucumbers. Herein, 16 isolates of the
Pediococcus
genus from various sources were tested for inhibitory activity against
L. plantarum
and other microorganisms by a seeded-agar screening technique. Only two of the 16 isolates gave consistent and distinctive zones of inhibition, and both were isolated from fermenting cucumber brines on separate occasions. These two isolates did not inhibit each other but did inhibit the other 14
Pediococcus
isolates in addition to
L. plantarum
. They also inhibited several other gram-positive bacteria, but not four species each of gram-negative bacteria and yeasts tested. Inoculation of cucumber juice broth with
P. cerevisiae
FBB-61 and
L. plantarum
WSO resulted in a drastic reduction in the plate count of
L. plantarum
WSO during day 1, but counts increased rapidly thereafter. Consequently, acid production by
L. plantarum
WSO was delayed. Noninhibitory isolates of
Pediococcus
had no appreciable effect on growth and acid production by
L. plantarum
WSO.
Improved method of selection for mutants of Pseudomonas putida
Authors: Carhart G , Hegeman G
Published: December 2020

Optimum conditions for enrichment of mutants of Pseudomonas putida in liquid culture were established using a procedure which combines N-methyl-N'-nitro-N-nitrosoguanidine mutagenesis with an improved D-cycloserine selection.
Fate of ochratoxin A in brewing
Authors: Nip W K , Chang F C , Chu F S , Prentice N
Published: December 2020

The fate of ochratoxin A in brewing was investigated by adding (3H)ochratoxin A to the raw materials at 1- and 10-mug/g levels during mashing in a conventional microbrewing process. The results indicated that large portions (28 to 39%) of the added toxin were recovered in spent grains, with less recovery in the yeast (8 to 20%) and beer (14 to 18%). About 38 and 12% of the added toxin at levels of 1 and 10 mug/g, respectively, were degraded during brewing.
Effect of initial pH on aflatoxin production
Authors: Buchanan R L , Ayres J C
Published: December 2020

The effect of initial pH on aflatoxin production by Aspergillus parasiticus NRRL 2999 was examined in a semisynthetic medium. Maximal growth, aflatoxin production, and aflatoxin production per unit of growth occurred at initial pH levels of 5.0, 6.0, and 7.0 respectively. Initial pH levels less than pH 6.0 favored production of the B toxins, whereas levels greater than pH 6.0 favored production of the G toxins.
Effect of substrates on acetoin production by Torulopsis colliculosa and Enterobacter species
Authors: Yadav N K , Gupta K G
Published: December 2020

Under optimal conditions, Torulopsis colliculosa NRRL 172 and Enterobacter B-87 (ATCC 27613) produced 50 to 500 mg of acetoin per g of substrate. Whereas cane molasses, gur, glucose, and sucrose were suitable substrates for acetoin production, lactose and mannitol supported very good growth but yielded little or no acetoin. Production of acetoin increased with increases in the concentration of glucose, yeast extract, and peptone. Combination of substrates and intermittent feeding of substrate failed to increase the yields.
High-temperature production of protein-enriched feed from cassava by fungi
Authors: Reade A E , Gregory K F
Published: December 2020

A simple, nonaseptic, low-cast process for the conversion of cassava, a starchy tropical root crop, into microbial protein for use as animal feed was sought. Screening tests culminated in the isolation of a thermotolerant, amylase-producing mold, designated I-21, which was identified as Aspergillus fumigatus. The optimum pH for protein synthesis was 3-5, but the optimum temperature was less than the desired temperature (larger than or equal to 45 C) required for a nonaseptic fermentation. A. fumigatus I-21 and its asporogenous mutant I-21A grew equally well in a medium prepared from whole cassava roots with a mean protein doubling time at 45 C and pH 3.5 of 3.5 h. In batch culture, approximately 4% carbohydrate, supplied as whole cassava, could be feremented in 20 h, giving a final yield of 24 g of dry product, containing 36.9% crude protein, per liter. The conversion of carbohydrate used to crude protein was 22.1%. When determined as amino acids, the protein content of the product, which contained cassava bark and other unfermented residues, was 27.1%. With urea as the nitrogen source, no pH control was necessary. Preliminary data indicated that medium prepared from whole cassava roots was inhibitory to the mold unless the cassava pulp was heated to 70 C immediately after being ground. Heating to 70 C was required to gelatinize the starch and permit its complete utilization.
Removal of algae from Florida lakes by magnetic filtration
Authors: Bitton G , Fox J L , Strickland H G
Published: December 2020

Magnetic filtration was used for the removal of algal populations present in five lakes located in the vicinity of Gainesville, Fla. It was found that the use of this technique enabled a good removal (94%) of algal cells from three lakes where the pH was around 7. The other two lakes, with a higher pH, displayed a lower removal. However, the treatment was greatly improved by lowering the pH from 9.5 to 6.5.