bluuebunny/crossref_metadata_2025 huggingface dataset:
Survival of poliovirus within organic solids during chlorination
Authors: Hejkal T W , Wellings F M , LaRock P A , Lewis A L
Published: January 2020

Poliovirus in fecal homogenates was used to determine the protection against inactivation by chlorination afforded virus that was occluded within particulates. Virus that was closely associated with or occluded within small fecal particulates was protected. A fourfold increase in combined residual chlorine was required to achieve the same degree of inactivation for occluded virus as for free or secondarily adsorbed virus. A combined chlorine residual of 6.6 mg/liter was necessary to achieve 50% inactivation in 15 min at pH 8.0 and 22 degrees C in a particulate suspension containing occluded virus compared to 1.4 mg/liter for free virus. These differences were found to be relatively small compared to differences due to the presence of dissolved organics or between free and combined chlorine residuals. The results suggest different mechanisms of protection due to adsorption and occlusion.
Examination of Methods for Enumerating Hemicellulose-Utilizing Bacteria in the Rumen
Authors: Henning Penelope A.
Published: January 2020

Counts of colonies that developed after 4 days on agar medium containing 0.3% xylan and preincubated rumen fluid were similar to counts of xylanolytic bacteria obtained when total culturable counts were multiplied by the percentage of isolates capable of producing acid from xylan. Shortening the incubation period reduced the chance of including satellite colonies of non-xylanolytic organisms in the count. Nearly all of the xylanolytic isolates irrespective of the medium from which they were isolated degraded and utilized xylan extensively. The use of a culture medium containing a high concentration (3%) of xylan is also described. The number of colonies capable of producing clearings in this medium was less than 10% of the total culturable counts. Isolates from such colonies were shown to produce diffusible (extracellular) xylanases.
Reduction of endogenous nucleic acid in a single-cell protein
Authors: Yang H H , Thayer D W , Yang S P
Published: January 2020

The reduction of nucleic acid by an endogenous polynucleotide phosphorylase and ribonuclease in cells of Brevibacterium JM98A (ATCC 29895) was studied. A simple process was developed for the activation of the endogenous RNA-degrading enzyme(s). RNA degradation was activated by the presence of Pi with 14.2 mumol of ribonucleoside 5'-monophosphate per g of cell mass accumulating extracellularly. The optimum pH for degradation of RNA was 10.5 and the optimum temperature was 55 to 60 degrees C. Enzymatic activity was inhibited by the presence of Ca2+, Zn2+, or Mg2+. Although some of the RNA-degrading enzymatic activity was associated with the ribosomal fraction, most was soluble. Both polynucleotide phosphorylase and ribonuclease activities were identified.
Rumen Anaerobic Fungi of Cattle and Sheep
Authors: Bauchop T.
Published: January 2020

Plant fragments obtained from natural rumen digesta of fistulated cattle and sheep were examined by scanning electron microscopy. Various plant materials suspended in the rumen for different times were examined likewise. By 2 h large numbers of phycomycetous fungal zoospores were found attached to fibrous plant fragments, particularly vascular tissues. The subsequent development of these fungi resulted in production of thalli with extensive rhizoids and with sporangia up to 175 μm long. Scanning electron microscope examination of plant fragments randomly selected from natural rumen contents of both cattle and sheep demonstrated widespread colonization by large populations of these anaerobic fungi. Furthermore, all plant fragments suspended in nylon bags in the rumen were also extensively colonized. These findings demonstrate that plant fragments in the rumen are the sites of colonization and development by the anaerobic phycomycetous fungi. In addition, the results suggest that these fungi may form a significant part of the rumen microbiota in cattle and sheep fed on fibrous diets and suggest that they may be important in fiber digestion.
Bovine superoxide dismutase and copper ions potentiate the bactericidal effect of autoxidizing cysteine
Authors: Nyberg G K , Granberg G P , Carlsson J
Published: January 2020

When cysteine is oxidized by oxygen, hydrogen peroxide is formed, and hydrogen peroxide is very toxic to Peptostreptococcus anaerobius VPI 4330-1. Native and inactivated superoxide dismutase increased the rate of oxidation of cysteine and thereby potentiated the toxic effect of cysteine. A similar increase in the rate of oxidation of cysteine and in the toxicity of cysteine was obtained with Cu2+.
Biochemical properties of penicillin amidohydrolase from Micrococcus luteus
Authors: Nam D H , Ryu D D
Published: January 2020

Some biochemical properties of whole-cell penicillin amidohydrolase from Micrococcus luteus have been studied. This whole-cell enzyme showed its maximal activity at 36 degrees C at pH 7.5. It was found that the activation energy of this enzyme was 8.03 kcal (ca. 33.6 kJ) per mol, and this amidohydrolase showed first-order decay at 36 degrees C. The penicillin amidohydrolase was deactivated rapidly at temperatures above 50 degrees C during storage or preincubation for 24 h. The Michaelis constant, Km, for penicillin G was determined as 2.26 mM, and the substrate inhibition constant, Kis, was 155 mM. The whole-cell penicillin amidohydrolase from M. luteus was capable of hydrolyzing penicillin G, penicillin V, ampicillin, and cephalexin, but not cephalosporin C and cloxacillin. This whole-cell enzyme also had synthetic activity for semisynthetic penicillins or cephalosporins from D-(--)-alpha-phenylglycine methyl ester and 6-alpha-aminopenicillanic acid or 7-amino-3-deacetoxycephalosporanic acid.
Diurnal Cycle of Oxygen and Sulfide Microgradients and Microbial Photosynthesis in a Cyanobacterial Mat Sediment
Authors: Jørgensen Bo B. , Revsbech Niels P. , Blackburn T. Henry , Cohen Yehuda
Published: January 2020

The diurnal variation in the microgradients of O
2
, H
2
S, and Eh were studied in the benthic cyanobacterial mats of a hypersaline desert lake (Solar Lake, Sinai). The results were related to light intensity, light penetration into the mat, temperature, pH, NH
4
+
, photosynthetic activity, pigments, and the zonation of the microbial community. Extreme diurnal variation was found, with an O
2
peak of 0.5 mM at 1 to 2 mm of depth below the mat surface during day and a H
2
S peak of 2.5 mM at 2 to 3 mm of depth at night. At the O
2
-H
2
S interface, the two compounds coexisted over a depth interval of 0.2 to 1 mm and with a turnover time of a few minutes. The photic zone reached 2.5 mm into the mat in summer, and the main
14
CO
2
light fixation took place at 1 to 2 mm of depth. During winter, light and photosynthesis were restricted to the uppermost 1 mm. The quantitative dynamics of O
2
and H
2
S were calculated from the chemical gradients and from the measured diffusion coefficients.
Continuous Cultivation for Apparent Optimization of Defined Media for
Cellulomonas
sp. and
Bacillus cereus
Authors: Summers R. J. , Boudreaux D. P. , Srinivasan V. R.
Published: January 2020

Steady-state continuous culture was used to optimize lean chemically defined media for a
Cellulomonas
sp. and
Bacillus cereus
strain T. Both organisms were extremely sensitive to variations in trace-metal concentrations. However, medium optimization by this technique proved rapid, and multifactor screening was easily conducted by using a minimum of instrumentation. The optimized media supported critical dilution rates of 0.571 and 0.467 h
−1
for
Cellulomonas
and
Bacillus
, respectively. These values approximated maximum growth rate values observed in batch culture.
Asymmetric diphenol formation by a fungal laccase
Authors: Bollag J M , Liu S Y , Minard R D
Published: January 2020

A laccase isolated from the fungus Rhizoctonia praticola catalyzed the cross-coupling of two differently halogenated phenols. When 2,4-dichlorophenol and 4-bromo-2-chlorophenol were incubated together with the enzyme, three dimers were formed and isolated by thin-layer chromatography. The molecular weights of these compounds were determined by mass spectrometry as 322, 410, and 366, which correspond with the respective dimers of each of the phenols and with a hybrid formed from both, tentatively assigned the structure 3,3',5'-trichloro-5-bromo-2,2'-diphenol. Gas chromatography-mass spectrometry analysis of these products and of their methylated derivatives lent support to these structural assignments.
Action of egg white lysozyme on Clostridium tyrobutyricum
Authors: Wasserfall F , Teuber M
Published: January 2020

A 500-U ml-1 portion of egg white lysozyme was able to kill 99% of 5 X 10(5) resting vegetative cells of Clostridium tyrobutyricum within 24 h of incubation at 25 degrees C. Spores were completely resistant to lysozyme. Proliferating vegetative cells were severely inhibited, although lysozyme-resistant cells developed in growing cultures in the presence of lysozyme. Whereas early stages of spore germination (loss of optical refractility and heat resistance) were not inhibited by lysozyme, the overall outgrowth of spore cells into vegetative cells was delayed by 1 day in the presence of 500 U of lysosyme ml-1. This delay was independent of the lysozyme sensitivity or resistance of the mother culture of the used spores. It is suggested that this inhibition by lysozyme of the outgrowth of spore cells into vegetative cells of the lactate-fermenting C. tyrobutyricum is the basis for the observation that lysozyme can substitute for nitrate in preventing the "late gas" defect of Edam- and Gouda-type cheeses.
Toxins of molds from decaying tomato fruit
Authors: Harwig J , Scott P M , Stoltz D R , Blanchfield B J
Published: January 2020

Among 27 mold isolates from decaying tomatoes, culture filtrates or ethyl acetate extracts of 8 isolates grown in yeast extract-sucrose medium were markedly toxic (mortality, greater than 50%) to brine shrimp larvae. The toxicity of six of these isolates could be attributed to the presence of citrinin, tenuazonic acid, or T-2 toxin. Ethyl acetate extracts of five Alternaria isolates and one Fusarium isolate were mutagenic for Salmonella typhimurium strains. In ripe tomatoes inoculated with toxin-producing isolates and incubated at 25 degrees C, one Alternaria alternata isolate produced tenuazonic acid in seven of seven tomatoes at levels of up to 106 micrograms/g and alternariol methyl ether in one of the seven tomatoes at 0.8 microgram/g. Another A. alternata isolate produced tenuazonic acid or alternariol methyl ether at much lower levels in only three of seven tomatoes. Patulin and citrinin were produced by a Penicillium expansum isolate at levels of up to 8.4 and 0.76 microgram/g, respectively. In tomatoes incubated at 15 degrees C, a Fusarium sulphureum isolate produced T-2 toxin, HT-2 toxin, and neosolaniol at levels of up to 37.5, 37.8 and 5.6 micrograms/g, respectively. If these mycotoxins are thermostable, they may occur at detectable levels in tomato products whenever partially moldy tomatoes are used as raw material.
Bioaccumulation and depuration of enteroviruses by the soft-shelled clam, Mya arenaria
Authors: Metcalf T G , Mullin B , Eckerson D , Moulton E , Larkin E P
Published: January 2020

Low levels of feces-associated natural virus, simulating virus numbers estimated to exist in moderately polluted shellfish-growing waters, were used to evaluate the effectiveness of depuration as a virus depletion procedure in soft-shell clams. Depuration effectiveness depended upon the numbers of virus bioaccumulated and whether virus was solids associated. Virus uptake was greatest when viruses were solids associated and pollution levels were equivalent or greater than those likely to be found in grossly polluted growing waters. Virtually all bioaccumulated feces-associated natural virus was deposited within either the hepatopancreas or siphon tissues. Viruses usually were eliminated within a 24- to 48-h depuration period. Dependence upon depuration of clams to elimate health hazards of virus etiology involved a risk factor not measureable in the study. The greatest reduction of health risks would come from the routine depuration of clams harvested from growing waters of good sanitary quality.
Production and isolation of chitosan from Mucor rouxii
Authors: White S A , Farina P R , Fulton I
Published: January 2020

A method for the lab-scale production and isolation of chitosan (polyglucosamine) from hyphal walls of Mucor rouxii was developed. Hyphal wall yields were generally 16 to 22% on a dry cell weight basis, of which 35 to 40% was glucosamine. Chitosan was readily extracted from purified, mycelial walls with acetic, formic, and hydrochloric acids; the last named was the most efficient. The yield of chitosan isolated ranged from 4 to 8% of the dry weight of the cell wall material.
Arylsulfatase Activity in Salt Marsh Soils
Authors: Oshrain R. L. , Wiebe W. J.
Published: January 2020

The presence of arylsulfatase(s) was confirmed in salt marsh soils. The temperatures of maximum activity and inactivation, the pH range over which the enzyme was active, and the

K
m

values were similar to those of soil enzymes. Unlike soil arylsulfatases, however, the salt marsh enzymes do not appear to be repressed by sulfate. It is postulated that these enzymes may be necessary for the initiation of arylsulfate ester metabolism.
Evaluation of millipore coli-count samplers for monitoring fecal coliforms in the blue crab, Callinectes sapidus
Authors: Richards G P
Published: January 2020

Analyses of crab meat homogenates with Coli-Count Samplers (Millipore Corp.) resulted in fecal coliform counts comparable to counts obtained from standard most-probable-number testing procedures.
Muramic Acid Assay in Sediments
Authors: Fazio Steven D. , Mayberry William R. , White David C.
Published: January 2020

An improved chromatographic assay for muramic acid which is sufficiently sensitive for marine sandy sediments is described; it involves acid hydrolysis, thin-layer chromatography, and gas-liquid chromatography.
Comparison of m-Endo LES, MacConkey, and Teepol media for membrane filtration counting of total coliform bacteria in water
Authors: Grabow W O , du Preez M
Published: January 2020

Total coliform counts obtained by means of standard membrane filtration techniques, using MacConkey agar, m-Endo LES agar, Teepol agar, and pads saturated with Teepol broth as growth media, were compared. Various combinations of these media were used in tests on 490 samples of river water and city wastewater after different stages of conventional purification and reclamation processes including lime treatment, and filtration, active carbon treatment, ozonation, and chlorination. Endo agar yielded the highest average counts for all these samples. Teepol agar generally had higher counts then Teepol broth, whereas MacConkey agar had the lowest average counts. Identification of 871 positive isolates showed that Aeromonas hydrophila was the species most commonly detected. Species of Escherichia, Citrobacter, Klebsiella, and Enterobacter represented 55% of isolates which conformed to the definition of total coliforms on Endo agar, 54% on Teepol agar, and 45% on MacConkey agar. Selection for species on the media differed considerably. Evaluation of these data and literature on alternative tests, including most probable number methods, indicated that the technique of choice for routine analysis of total coliform bacteria in drinking water is membrane filtration using m-Endo LES agar as growth medium without enrichment procedures or a cytochrome oxidase restriction.
Binding Characteristics of N
2
-Fixing Bacteria to Cereal Roots
Authors: Shimshick Edward J. , Hebert Richard R.
Published: January 2020

The attachment of
Rhizobium japonicum
61A89 and
Rhizobium
spp. 32H1 to the roots of wheat and rice seedlings is analyzed in terms of an equilibrium model. A Langmuir adsorption isotherm describes the binding. Strain 61A89 binds to a greater extent than does strain 32H1, and the equilibrium constants for each strain binding to wheat are strongly temperature dependent. Both time-dependent dissociation and association, predicted by an equilibrium model, have been found. The dissociation rate constant for 32H1 is approximately twice that of 61A89, and each is weakly temperature dependent. The rate equation for the binding of exponentially growing 61A89 to wheat roots has been solved as a function of time. Theory and experiment both indicate that the binding at very short times is much less than the equilibrium values. The binding of
Azotobacter vinelandii
12837 to wheat roots has also been measured. Root-associated
Azotobacter
fixes nitrogen, whereas under aerobic growth conditions, root-associated 61A89 and 32H1 do not. The effect of metabolic inhibitors and antibiotics on the binding of
Rhizobia
and
Azotobacter
was examined.
Respiration and viability of thermally injured Saccharomyces cerevisiae
Authors: Graumlich T R , Stevenson K E
Published: January 2020

Resting cells of Saccharomyces cerevisiae Y25 were heated at 56 degrees C for 0 to 2 min. Respiratory activity of the cells reflected the severity of the heat stress. The endogenous respiration was approximately 50 microliter of O2/mg per h for cells heated for 2 min at 56 degrees C as compared with 2 microliter of O2/mg per h for nonheated cells. There was a distinct decrease in respiration after 1 to 3 h, and after 20 h the respiration rate of heated cells was less than that of nonheated cells. Along with increased rates of endogenous respiration, respiratory quotients of cells were altered after heat stress. Addition of 2,4-dinitrophenol stimulated O2 (uptake) in nonheated cells but decreased O2 (uptake) of heated cells. Due to the high rate of endogenous respiration, addition of glucose resulted in no substantial change in the rate of respiration of heated cells. However, addition of glucose prolonged the presence of the high rates of respiration observed in heated cells.
Role of plasmids in mercury transformation by bacteria isolated from the aquatic environment
Authors: Olson B H , Barkay T , Colwell R R
Published: January 2020

Eight mercury-resistant bacterial strains isolated from the Chesapeake Bay and one strain isolated from the Cayman Trench were examined for ability to volatilize mercury. Mercury volatilization was found to be variable in the strains tested. In addition, plasmids were detected in all strains. After curing, two of the bacterial strains lost mercury resistance, indicating that volatilization is plasmid mediated in these strains. Only two cultures demonstrated ability to methylate mercuric chloride under either aerobic or anaerobic conditions. Methylation of mercury, compared with volatilization, appears to be mediated by a separate genetic system in these bacteria. It is concluded that mercury volatilization in the estuarine environment can be mediated by genes carried on plasmids.
Denitrification, Acetylene Reduction, and Methane Metabolism in Lake Sediment Exposed to Acetylene
Authors: Knowles Roger
Published: January 2020

Samples of sediment from Lake St. George, Ontario, Canada, were incubated in the laboratory under an initially aerobic gas phase and under anaerobic conditions. In the absence of added nitrate (NO
3
−
) there was O
2
-dependent production of nitrous oxide (N
2
O), which was inhibited by acetylene (C
2
H
2
) and by nitrapyrin, suggesting that coupled nitrification-denitrification was responsible. Denitrification of added NO
3
−
was almost as rapid under an aerobic gas phase as under anaerobic conditions. The N
2
O that accumulated persisted in the presence of 0.4 atm of C
2
H
2
, but was gradually reduced by some sediment samples at lower C
2
H
2
concentrations. Low rates of C
2
H
2
reduction were observed in the dark, were maximal at 0.2 atm of C
2
H
2
, and were decreased in the presence of O
2
, NO
3
−
, or both. High rates of light-dependent C
2
H
2
reduction occurred under anaerobic conditions. Predictably, methane (CH
4
) production, which occurred only under anaerobiosis, was delayed by added NO
3
−
and inhibited by C
2
H
2
. Consumption of added CH
4
occurred only under aerobic conditions and was inhibited by C
2
H
2
.
Microbial conversion of ethylbenzene to 1-phenethanol and acetophenone by Nocardia tartaricans ATCC 31190
Authors: Cox D P , Goldsmith C D
Published: January 2020

A culture of Nocardia tartaricans ATCC 31190 was capable of catalyzing the conversion of ethylbenzene to 1-phenethanol and acetophenone while growing in a shake flask culture with hexadecane as the source of carbon and energy. This subterminal oxidative reaction with ethylbenzene appears not to have been previously reported for Nocardia species. When N. tartaricans was grown on glucose as its source of carbon and energy and ethylbenzene was added, no subsequent production of 1-phenethanol or acetophenone was observed. The mechanisms of 1-phenethanol and acetophenone production from ethylbenzene are thought to involve a subterminal oxidation of the alpha-carbon of the alkyl group to 1-phenethanol followed by biological oxidation of the latter to acetophenone.
Duration of Hydrogen Formation by
Anabaena cylindrica
B629 in Atmospheres of Argon, Air, and Nitrogen
Authors: Lambert Grant R. , Daday Arlene , Smith Geoffrey D.
Published: January 2020

The time course of hydrogen formation by
Anabaena cylindrica
was followed beneath an argon atmosphere alone and also beneath atmospheres of argon, nitrogen, and air in the presence of carbon monoxide (0.2%) and acetylene (5%). Hydrogen production beneath argon alone was comparable in rate and duration (7 to 12 days) to that which occurred beneath air in the presence of carbon monoxide (0.2%) and acetylene (5%). However, much greater longevity (16 to 26 days) and improved rates of hydrogen formation were obtained when algae were incubated beneath argon and particularly nitrogen, each supplemented with carbon monoxide and acetylene. The total hydrogen produced by these cultures was up to three times as much as that released by cultures incubated beneath argon alone. Hydrogen-oxygen ratios for argon cultures either with or without carbon monoxide and acetylene were initially 1:5 but approximated 1:2 when measured over the entire incubation period. In each case oxygen production and nitrogenase activity (acetylene reduction) continued at reduced rates after hydrogen evolution had ceased. The effects of methionine sulfoximine (2 μM), ammonium ions (0.5 mM), or both on oxygen production were generally negligible, while effects on hydrogen production were variable depending on the atmosphere used; in most cases, eventual destabilization of the system occurred. A brief comparison was made of the time courses of anaerobic and aerobic hydrogen formation by the marine cyanobacterium
Calothrix membranacea
. It was found that shaking of cultures was beneficial for hydrogen production but not strictly necessary. It is concluded that hydrogen production by
A. cylindrica
in air and particularly nitrogen in the presence of carbon monoxide and acetylene offers the best potential of the atmospheres considered on the basis of four criteria: rates and longevity of hydrogen formation, practicality of the atmosphere used, and tolerance of hydrogen evolution to slight changes in composition of the atmosphere.
General Properties of Beta-Galactosidase of
Xanthomonas campestris
Authors: Frank Joseph F. , Somkuti George A.
Published: January 2020

Partially purified β-galactosidase of
Xanthomonas campestris
required 32 to 37�C and pH 5.5 to 5.8 for optimum activity. The enzyme had low affinity for lactose hydrolysis (

K
m

= 22 mM) and was inhibited by thiol group reagents, ethylenediaminetetraacetic acid, galactose, and
d
-galactal.
MICRID: a computer-assisted microbial identification system
Authors: Kellogg S T
Published: January 2020

An extensive computer-assisted identification system for bacteria and yeasts (117 genera and 1,430 species) was developed, and applications proved very useful in teaching situations.
Algae/Bacteria Ratio in High-Rate Ponds Used for Waste Treatment
Authors: Oron Gideon , Shelef Gedaliah , Levi Anna , Meydan Arie , Azov Yossef
Published: January 2020

Algae, bacteria, and zooplankton were counted in samples drawn from 120- and 150-m
2
high-rate algae ponds (those used for wastewater treatment). The fraction of nondegraded organic matter was estimated by comparing the ratio of biological and chemical oxygen demands and the bacterial, algal, and zooplankton counts to volatile suspended solids. With pond effluent quality at an acceptable level (around 18 mg of dissolved biological oxygen demand), the algae/bacteria ratio was around 1:100 or even higher, the zooplankton count was negligible, and the bacterial concentration was approximately 10
11
cells per liter by direct count. The data for bacteria exceeded those of earlier studies by one to three orders of magnitude.
Enterovirus inactivation in soil
Authors: Yeager J G , O'Brien R T
Published: January 2020

The inactivation of radioactively labeled poliovirus type 1 and coxsackievirus B 1 in soils saturated with surface water, groundwater, and septic tank liquor was directly proportional to temperature. Virus persistence was also related to soil type and the liquid amendment in which viruses were suspended. At 37 degrees C, no infectivity was recovered from saturated soil after 12 days; at 4 degrees C, viruses persisted for at least 180 days. No infectivity was recovered from dried soil regardless of temperature, soil type, or liquid amendment. Additional experiments showed that evaporation of soil water was largely responsible for the decreased recovery of infectivity from drying soil. Increased rates of virus inactivation at low soil moisture levels were also demonstrated.
Structural changes associated with poliovirus inactivation in soil
Authors: Yeager J G , O'Brien R T
Published: January 2020

The loss of infectivity of poliovirus in moist and dried soils was a result of irreversible damage to the virus particles. The damage included (i) dissociation of viral genomes and capsids and (ii) degradation of viral ribonucleic acid (RNA) in the soil environment. Under drying conditions, capsid components could not be recovered from the soils. Further studies in sterile soils indicated that, under moist conditions, the viral RNA was probably damaged before dissociation from the capsid. However, in sterile, dried soil, RNA genomes were recovered largely intact from the soil. These results suggest that polioviruses are inactivated by different mechanisms in moist and drying soils.
Edwardsiella tarda in freshwater catfish and their environment
Authors: Wyatt L E , Nickelson R , Vanderzant C
Published: January 2020

Edwardsiella tarda was isolated from 47, 88, and 79% of skin, visceral, and dressed-fish samples, respectively. This species was also isolated from 30% of imported dressed fish, 75% of catfish pond water samples, 64% of catfish pond mud samples, and 100% of frogs, turtles, and crayfish from catfish ponds. The incidence of Edwardsiella increased during the summer months, as water temperatures increased. Of several isolation media evaluated, the most effective was selective enrichment in double-strength Salmonella-Shigella broth and subsequent plating on single-strength Samonella-Shigella agar. The significance of the incidence of Edwardsiella in catfish, catfish disease, and public health could not be substantiated.
Assessment of Microbial Fouling in an Ocean Thermal Energy Conversion Experiment
Authors: Aftring R. Paul , Taylor Barrie F.
Published: January 2020

A project to investigate biofouling, under conditions relevant to ocean thermal energy conversion heat exchangers, was conducted during July through September 1977 at a site about 13 km north of St. Croix (U.S. Virgin Islands). Seawater was drawn from a depth of 20 m, within the surface mixed layer, through aluminum pipes (2.6 m long, 2.5-cm internal diameter) at flow velocities of about 0.9 and 1.8 m/s. The temperature of the seawater entering the mock heat exchanger units was between 27.8 and 28.6°C. After about 10 weeks of exposure to seawater, when their thermal conductivity was reported to be significantly impaired, the pipes were assayed for the accumulation of biological material on their inner surfaces. The extent of biofouling was very low and independent of flow velocity. Bacterial populations, determined from plate counts, were about 10
7
cells per cm
2
. The ranges of mean areal densities for other biological components were: organic carbon, 18 to 27 μg/cm
2
; organic nitrogen, 1.5 to 3.0 μg/cm
2
; adenosine 5′-triphosphate, 4 to 28 ng/cm
2
; carbohydrate (as glucose in the phenol assay), 3.8 to 7.0 μg/cm
2
; chlorophyll
a
, 0.2 to 0.8 ng/cm
2
. It was estimated from the adenosine 5′-triphosphate and nitrogen contents that the layer of live bacteria present after 10 weeks was only of the order of 1μm thick. The C/N ratio of the biological material suggested the presence of extracellular polysaccharidic material. Such compounds, because of their water-retaining capacities, could account for the related increase in thermal resistance associated with the pipes. This possibility merits further investigation, but the current results emphasize the minor degree of biofouling which is likely to be permissible in ocean thermal energy conversion heat exchangers.
Expansion of the host range of coliphage P1 and gene transfer from enteric bacteria to other gram-negative bacteria
Authors: Murooka Y , Harada T
Published: January 2020

The bacterial host range of coliphage P1 was extented by using the heat-inducible phage P1clr100KM. A gene for kanamycin resistance was transferred from Escherichia coli to members of the family Enterobacteriaceae and some other genera of gram-negative bacteria. P1 phage was produced by thermal induction from the lysogens of all these kanamycin-resistant bacteria except some strains.
Asparaginase production by human clinical isolates of Vibrio succinogenes
Authors: Radcliffe C W , Kafkewitz D , Abuchowski A
Published: January 2020

Three human isolates of Vibrio succinogenes produced asparaginase. Apparent Km's were 87,220, and 320 microM. The rate of glutamine hydrolysis was between 2.8 and 3.5% of the rate of asparagine hydrolysis. Asparaginase production was not induced by ammonium ions, and enzyme yields were lower than those obtained with the rumen strain.
Role of the fly in the transport of Yersinia enterocolitica
Authors: Fukushima H , Ito Y , Saito K , Tsubokura M , Otsuki K
Published: January 2020

Yersinia enterocolitica were isolated from flies collected from a piggery and a kitchen of farm and from ham hung in a piggery. The cultures were identified as Y. enterocolitica biovar 4 and serovar 3 by biochemical and serological characteristics. From these results it is suggested that flies may play an important role in food contamination by Y. enterocolitica. In this study, the probable donors of Y. enterocolitica to the flies were swine.
Mutagenicity of 5,6-dimethoxysterigmatocystin, a metabolite from Aspergillus multicolor, in the Salmonella/microsome system
Authors: Wehner F C , Thiel P G , Vleggaar R
Published: January 2020

The natural sterigmatocystin derivative, 5,6-dimethoxysterigmatocystin, was found to be a mutagen for Salmonella typhimurium strains TA98 and TA100 after metabolic activation in a mammalian microsome system.
Isolation of
cis
-3-Amino-
l
-Proline from Cultured Mycelia of
Morchella esculenta
Fr
Authors: Moriguchi Mitsuaki , Sada Shin-Ichi , Hatanaka Shin-Ichi
Published: January 2020

cis
-3-Amino-
l
-proline, identified once as a nonprotein amino acid from the fruiting bodies of
Morchella esculenta
Fr., was isolated also from the growth medium and cultured mycelia of the same fungus.
Medium for the presumptive identification of Aeromonas hydrophila and Enterobacteriaceae
Authors: Kaper J , Seidler R J , Lockman H , Colwell R R
Published: January 2020

A medium was devised for the rapid presumptive identification of Aeromonas hydrophila. It also offered good differentiation of Klebsiella, Proteus, and other enteric species. Mannitol fermentation, inositol fermentation, ornithine decarboxylation and deamination, indole production, motility, and H2S production from sodium thiosulfate and cysteine could be recorded in a single tube of the medium.
Role of bovine serum albumin in the nutrition of Mycobacterium tuberculosis
Authors: Lynn M , Wilson A R , Solotorovsky M
Published: January 2020

Bovine serum albumin promotes the growth of small inocula of Mycobacterium tuberculosis in media containing unesterified fatty acids. Albumin binds fatty acids present in concentrations toxic for the organisms. In the present study, additional roles of albumin were investigated. When present in a basal medium, fatty acid-free albumin could be utilized by M. tuberculosis as a sole source of carbon. Since albumin could not substitute for the amino acids in basal medium as a nitrogen source, it was concluded that the protein component in albumin was not utilized as a nutrient by the organisms. An ether extract of fatty acid-free albumin supported a small but significant amount of growth. Analysis of the lipids in fatty acid-free albumin by gas chromatography revealed the presence of 686 microgram of fatty acid per g of albumin. Although a small amount of growth occurred when a lipid extract of albumin was present in the medium, growth stimulation was dependent in major part on the presence of undenatured albumin in the medium. Lipids, when bound to albumin, can serve as a nontoxic source of carbon and energy.
Heat inactivation of Mycobacterium avium-Mycobacterium intracellulare complex organisms in meat products
Authors: Merkal R S , Crawford J A , Whipple D L
Published: January 2020

Wieners and sausages were prepared which contained the most heat-tolerant representative of the Mycobacterium avium-Mycobacterium intracellulare complex we were able to obtain. They also were prepared with infected tissues obtained from tuberculous swine. Processing conditions were as varied as possible. Neither incorporation of sodium nitrite in the emulsion nor presence of smoke during processing altered the heat susceptibility of the organisms. Substantial killing of the organisms occurred as wieners reached the upper processing temperatures, but hot oil or radiant heating of the "precooked" sausages allowed very short times within the killing range; hence, higher peak internal temperatures were necessary. The lethalities for these organisms of reaching and maintaining various processing temperatures are given.
Distribution and metabolism of ingested NO3- and NO2- in germfree and conventional-flora rats
Authors: Witter J P , Balish E
Published: January 2020

Germfree and conventional-flora Sprague-Dawley rats were fed sodium nitrate or sodium nitrite in their drinking water (1,000 microgram/ml), and various organs, tissues, and sections of the intestinal tract were assayed for nitrate (NO3-) and nitrite (NO2-) by a spectrophotometric method. When fed NO3-, germfree rats had chemically detectable levels of NO3- (only) in the stomach, small intestine, cecum, and colon. Conventional-flora rats fed NO3- had both NO3- and NO2- in the stomach, but only NO3- in the small intestine and colon. When fed NO2-, germfree rats had both NO3- and NO2- in the entire gastrointestinal tract. Conventional-flora rats fed NO2- had both ions in the stomach and small intestine, but only NO3- in the large intestine. Conventional-flora rats fed NO3- or NO2- had lower amounts of these ions in the gastrointestinal tract than comparably fed germfree rats. Control (non-NO3- or NO2--fed) germfree and conventional-flora rats had trace amounts of NO3- (only) in their stomachs and bladders. These results, in conjunction with various in vitro studies with intestinal contents, suggest that NO3- or NO2- reduction is a function of the normal bacterial flora, whereas NO2- oxidation is attributable to the mammalian host. In addition, the distribution of these ions after their ingestion appears more widespread in the body than previously thought.
Comparison of homogenizing, shaking, and blending on the recovery of microorganisms and endotoxins from fresh and frozen ground beef as assessed by plate counts and the Limulus amoebocyte lysate test
Authors: Jay J M , Margitic S
Published: January 2020

Of three methods studied, brisk shaking of samples in dilution blanks by hand and homogenization by a stomacher were compared relative to their capacity to recover the endotoxins and viable bacteria; blending with a Waring blender was compared with these two methods only on the recovery of viable cells. Aerobic plate counts were essentially the same by the three methods for fresh meats, with the stomacher producing slightly higher aerobic plate counts and significantly higher gram-negative counts determined by violet red bile agar. The stomacher produced significantly higher aerobic plate counts and violet red bile agar results on frozen meats than did shaking. Endotoxins were determined by the Limulus amoebocyte lysate test; results by shaking and stomacher on 15 single samples of frozen meat were identical. Of Limulus amoebocyte lysate-negative beef which was spiked with known endotoxin, a higher percentage of recovery was obtained with the stomacher. Although both aerobic plate counts and violet red bile agar counts were found by shaking and stomacher to decrease significantly in frozen meats, endotoxin content was not significantly affected. The stomacher was found to be the better method overall, especially when meats are to be examined for their content of viable gram-negative bacteria, endotoxins, or both.
Science of hemolytic activity of some radiation-resistant micrococci in food
Authors: Welch A B , Maxcy R B
Published: January 2020

Micrococci resistant to 1 Mrad of gamma radiation were isolated from irradiated chicken. Three isolates were hemolytic on blood agar plates and were selected for further study. Two other radiation-resistant micrococci, Micrococcus radiodurans and Micrococcus radiophilus, were included in the study because there is only a very limited amount of information regarding hemolytic activity of these organisms and their potential role of public health importance. Tests to determine hemolytic patterns, hemolytic activity of extracellular substances, leukocytic activity, presence of enzymes commonly associated with pathogenicity (coagulase, deoxyribonuclease, phosphatase), and pathogenicity for laboratory animals all suggested that the organisms would not be of public health significance.
Statistical procedure for evaluating the sensitivity of Limulus amoebocyte lysate by using a reference lysate
Authors: Rastogi S C , Seligmann E B , Hochstein H D , Dawson J H , Farag L G , Marquina R E
Published: January 2020

A study was designed to estimate variability of the Limulus amoebocyte lysate test by comparing a reference lysate against itself. Three technicians performed parallel tests, i.e., titrated side by side, the contents of two vials of reference lysate on 4 different days using 24 vials of the United States reference lysate and 12 vials of the United States reference endotoxin. Each parallel test was replicated three times. From the sensitivity endpoints, ratios were calculated for each parallel test. These ratios were converted to the logarithm for estimating variability among technicians and among vials of endotoxin. By using the overall variability of log ratios, a statistical procedure was developed to evaluate the sensitivity of each lot of licensed lysate submitted to the Bureau of Biologics for release.
Distribution of the Luminous Bacterium
Beneckea harveyi
in a Semitropical Estuarine Environment
Authors: O'Brien Catherine H. , Sizemore Ronald K.
Published: January 2020

Bioluminescent bacteria were found in the water column, sediment, shrimp, and gastrointestinal tract of marine fishes from the semitropical estuarine environment of the East Lagoon, Galveston Island, Tex. Populations in the water column decreased during cold weather while sedimentary populations persisted. The highest percentages of luminous organisms were isolated from the gastrointestinal tract of marine fishes, where they persisted during 5 days of starvation. The presence of chitin temporarily increased intestinal populations. All isolates were
Beneckea harveyi,
whose natural habitat appears to be the gut of fishes and whose free-living reservoir appears to be marine sediments.
Toxicity of NO
2
: Effect of Nitrite on Microbial Activity in an Acid Soil
Authors: Bancroft Keith , Grant Ian F. , Alexander Martin
Published: January 2020

In an acid forest soil of pH 4.0 to 4.2 amended with glucose, 1.0 μg of nitrite-N per g of soil inhibited the rate of O
2
utilization and CO
2
evolution. The inhibition was evident only for several hours after nitrite addition, and the subsequent rate of glucose mineralization was the same as in soil not receiving nitrite. The decomposition of protein hydrolysate was reduced by 10 μg of nitrite-N per g of soil but not lower concentrations, and the inhibition of this process by 20 μg of nitrite-N per g had dissipated after 24 h. Nitrite disappeared readily from this soil. More than 20 μg of bisulfite-S per g of soil was required to inhibit glucose decomposition. The data suggest that the possible antimicrobial effects of low levels of NO
2
, which give rise to nitrite in soil, require further evaluation.
Liquid Chromatographic Determination of Dipicolinic Acid from Bacterial Spores
Authors: Warth A. D.
Published: January 2020

Dipicolinic acid was determined by reverse-phase liquid chromatography. Elution was with 0.2 M potassium phosphate, pH 1.8, containing 1.5%
tert
-amyl alcohol or higher concentrations of lower alcohols or acetonitrile. The normal analytical range was 50 to 1,000 μM, which is equivalent to 0.1 to 1 mg of spores per ml with a relative standard error of 2 to 4% and a detection limit of <100 pmol. Dipicolinic acid was fully extracted from spores by heating at pH 1.8 for 10 min at 100°C. Sporulating cultures may be analyzed in less than 20 min without separation of cells from media. Liquid chromatography was also used to detect dipicolinic acid in more complex substrates, e.g., guinea pig feces containing
Metabacterium polyspora
spores and canned food. Dipicolinic acid could be detected in unspoiled canned salmon containing <10
6
added
Bacillus cereus
spores per g.
Variability of Temperature, pH, and Moisture in an Aerobic Composting Process
Authors: Atchley Steven H. , Clark J. B.
Published: January 2020

This study measured the environmental variability which exists in a commercial aerobic composting process. The specific process studied is carried out in six decomposition cells which present six different phases of the process. Temperature, pH, and moisture content were determined in several randomly chosen sample sites in each cell, both at the beginning and at the end of the time the material was left in the cell. Temperature and pH varied greatly from one sample site to another in each cell, whereas moisture content was less varied. A significant rise in both temperature and pH was observed at two stages of degradation.
Evidence for the Existence of “Survival Factors” as an Explanation for Some Peculiarities of Yeast Growth, Especially in Grape Must of High Sugar Concentration
Authors: Lafon-Lafourcade S. , Larue F. , Ribereau-Gayon P.
Published: January 2020

The retardation and arrest of fermentation, observed before the complete sugar consumption of high-sugar grape must, come from an inhibition of the yeast metabolism during its decline phase and are variable with the strain. The addition of nutritional growth factors stimulates the initial growth of the yeast but is ineffective in the decline phase. Some substances, known previously as yeast anaerobic growth factors (sterols, oleanolic acid, oxytocin), in some conditions (initially aerated grape must and aerobically cultivated yeast) act by increasing the viability of the resting cells and prolonging their fermentation activity. These substances have been named “survival factors.”
Capture of Arginine at Low Concentrations by a Marine Psychrophilic Bacterium
Authors: Geesey Gill G. , Morita Richard Y.
Published: January 2020

The cells of the marine bacterium Ant-300 were found to take up arginine when this substrate was at low concentrations. The cells possessed an uptake system(s) that specifically transported
l
-arginine. The kinetic parameters for uptake appeared to differ when the cells were exposed to nanomolar and micromolar concentrations of the amino acid. Uptake over this concentration range functioned in the absence of an exogenous energy source, even after the cells had been preincubated in unsupplemented artificial seawater. Respiratory activity appeared to be a more important driving force for arginine uptake than adenosine 5′-triphosphate hydrolysis. The cells also exhibited chemotaxis toward
l
-arginine. The minimum arginine concentration needed to elicit a chemotactic response was between 10
−5
and 10
−6
M. It is proposed that the capture of arginine by cells of Ant-300 in nutrient-depleted waters, which are typical of the open ocean, proceeds via high-affinity active transport, whereas in substrate-enriched seawater, capture involves chemotaxis and an active transport mechanism with reduced affinity for the substrate.
Influence of Environmental Factors on Antagonism of Fungi by Bacteria in Soil: Clay Minerals and pH
Authors: Rosenzweig William D. , Stotzky G.
Published: January 2020

The soil replica plating technique was used to evaluate the influence of clay minerals and pH on antagonistic interactions between fungi and bacteria in soil. In general, the antagonistic activity of bacteria towards filamentous fungi was greater in soil than on agar. The spread of
Aspergillus niger
through soil was inhibited by
Serratia marcescens
when the organisms were inoculated into separate sites in soil, and this antagonistic effect was maintained when the soil was amended with 3, 6, 9, or 12% (vol/vol) montmorillonite, whereas the addition of kaolinite at a concentration of 3% reduced the antagonism and at 6, 9, or 12% totally eliminated it. Similar results were obtained with the inhibition of
A. niger
by
Agrobacterium radiobacter
and of
Penicillium vermiculatum
by either
S. marcescens
or
Nocardia paraffinae
. When
A. niger
and
S. marcescens
were inoculated into the same soil site,
A. niger
was inhibited in all soils, regardless of clay content, although the extent of inhibition was greater as the concentration of montmorillonite, but not of kaolinite, increased.
A. niger
was inhibited more when inoculated as spores than as mycelial fragments and when inoculated 96 h after
S. marcescens,
but a 1% glucose solution reduced the amount of inhibition when the fungus was inoculated 96 h after the bacterium. When the pH of the soil-clay mixtures was altered, the amount of antagonism usually increased as the pH increased. Antagonism appeared to be related to the cation-exchange capacity and the pH of the soil-clay mixtures.
Bacillus cereus
and another species of
Bacillus
showed no activity in soil towards
A. niger
under any of the environmental conditions tested, even though the
Bacillus
sp. significantly inhibited
A. niger
and seven other fungi on agar.
Nitrate and Nitrite Reduction by Microorganisms Embedded in a Filter Paper Incubated Aerobically
Authors: Hilali A. , Molina J. A. E.
Published: January 2020

Pseudomonas aeruginosa
, grown to steric saturation between the cellulose fibers of a filter paper, reduced nitrate or nitrite or both when the cell-filled paper was washed, transferred to phosphate buffer, nitrate, or nitrite or both, and glucose agar plates, and incubated under aerobiosis as resting cells. The biological nature of the reduction was ascertained by the use of nitrate and nitrite reductaseless mutants. The mesh of cellulose fibers was necessary to create a sufficient barrier to oxygen diffusion, since denitrification was not obtained within large and thick colonies of
P. aeruginosa
. When a soil suspension was used to inoculate the filter paper, ammonium and nitrite accumulated. Concomitant to nitrate reduction, the total nonvolatile inorganic nitrogen decreased and then increased as if part of it was immobilized to be subsequently mineralized.