bluuebunny/crossref_metadata_2025 huggingface dataset:
Construction and Characterization of Isogenic Series of
Saccharomyces cerevisiae
Polyploid Strains
Authors: Takagi Atsuko , Harashima Satoshi , Oshima Yasuji
Published: January 2020

Tetraploid cells of
Saccharomyces cerevisiae
are generated spontaneously in a homothallic

MAT
a/
MAT
α

diploid population at low frequency (approximately 10
−6
per cell) through the homozygosity of mating-type alleles by mitotic recombination followed by homothallic switching of the mating-type alleles. To isolate tetraploid clones more effectively, a selection method was developed that used a dye plate containing 40 mg each of eosin Y and amaranth in synthetic nutrient agar per liter. It was possible to isolate tetraploid clones on the dye plate at a frequency of 1 to 3% among the colonies colored dark red in contrast to the light red of the original diploid colonies. Isogenic series of haploid to tetraploid clones with homozygous or heterozygous genomic configurations were easily constructed with the tetraploid strains. No significant differences in specific growth rate or fermentative rate were observed corresponding to differences in ploidy, although the haploid clones showed a higher frequency of spontaneous respiratory-deficient cells than did the others. However, a significant increment in the fermentative rate in glucose nutrient medium was observed in the hybrid strains constructed with two independent homozygous cell lines. These observations strongly suggest that the polyploid strains favored by the brewing and baking industries perform well not because of the physical increment of the cellular volume by polyploidy but because of the genetic complexity or heterosis by heterozygosity of the genome in the hybrid polyploid cells.
Prevalence of
Campylobacter jejuni
in Chicken Wings
Authors: Kinde Hailu , Genigeorgis Constantin A. , Pappaioanou Marguerite
Published: January 2020

Campylobacter jejuni
was found in 82.9% of 94 chicken wing packages analyzed on the day of arrival at supermarkets and in 15.5% of 45 packages obtained from the supermarket shelves a few days later. The number of bacterial cells ranged from 10
2
to 10
3.9
per wing. The prevalence of
C. jejuni
in the wings varied with the brand, the day of sampling, and the age of the product.
Effects of cultural conditions on protease production by Aeromonas hydrophila
Authors: O'Reilly T , Day D F
Published: January 2020

Production of extracellular proteolytic activity by Aeromonas hydrophila was influenced by temperature, pH, and aeration. Conditions which produced maximal growth also resulted in maximal protease production. Enzyme production appeared to be modulated by an inducer catabolite repression system whereby NH4+ and glucose repressed enzyme production and complex nitrogen and nonglucose, carbon energy sources promoted it. Under nutritional stress, protease production was high, despite poor growth.
Ochratoxin A production by Aspergillus ochraceus Wilhelm grown under controlled atmospheres
Authors: Paster N , Lisker N , Chet I
Published: January 2020

When Aspergillus ochraceus NRRL 3174 was grown under controlled atmospheres with 1 and 5% O2 and without CO2, the amount of ochratoxin produced was the same as that produced by the control colonies. Increasing the O2 level up to 40% reduced ochratoxin production by 75%, whereas at 60% O2, ochratoxin production was enhanced. In atmospheres enriched with 10 or 20% CO2, ochratoxin production was reduced when O2 concentrations were below 20% and enhanced when the O2 concentration was 40 or 60% O2. Ochratoxin production was completely inhibited at 30% CO2 and above, regardless of the O2 level. Colony growth was partially inhibited at 60% CO2, and no growth occurred at 80% CO2 or above. However, when colonies inhibited by 60% CO2 or above were subsequently exposed to air, radial growth, number of sclerotia formed, and the amount of ochratoxin produced were the same as in the control colonies. The results indicate that A. ochraceus is tolerant to CO2 concentrations higher than those required to control storage insects.
Effect of Phenol Molecular Structure on Bacterial Transformation Rate Constants in Pond and River Samples
Authors: Paris Doris F. , Wolfe N. Lee , Steen William C. , Baughman George L.
Published: January 2020

Microbial transformation rate constants for a series of phenols were correlated with a property of the substituents, van der Waal's radius. Transformation products were the corresponding catechols, with the exception of
p
-hydroxybenzoic acid, the product of
p
-acetylphenol. A different product suggested a different pathway;
p
-acetylphenol, therefore, was deleted from the data base.
Relative Incidence of
Alteromonas putrefaciens
and
Pseudomonas putrefaciens
in Ground Beef
Authors: Parker Louise L. , Levin R. E.
Published: January 2020

Of 65 H
2
S-producing isolates from seven samples of ground beef, 64 were found to be
Alteromonas putrefaciens
. Isolates of
Pseudomonas putrefaciens
were not encountered. The mean guanine-plus-cytosine content of DNAs from 10 of the representative isolates, obtained from thermal denaturation determinations, was 46.5 ± 1.0 mol%, which is consistent with the designation
A. putrefaciens
.
Mineralization of Parathion in the Rice Rhizosphere
Authors: Reddy B. Rajasekhar , Sethunathan N.
Published: January 2020

We studied
14
CO
2
evolution from ring-labeled [2,6-
14
C]parathion (
O,O
-diethyl-
O-p
-nitrophenyl phosphorothioate) in the rhizosphere of rice seedlings. The soil samples (nonflooded [60% water-holding capacity] and flooded) were treated first with technical parathion (20 μg/g) and then after 10 days with ring-labeled [
14
C]parathion. In unplanted soil, less than 5.5% of the
14
C in the parathion was evolved as
14
CO
2
in 15 days under both flooded and nonflooded conditions. In soil planted with rice, 9.2% of the radiocarbon was evolved as
14
CO
2
under nonflooded conditions, and 22.6% was evolved under flooded conditions. These results suggest that soil planted with rice permits significant ring cleavage, especially under flooded conditions.
Chlorobium limicola
forma
thiosulfatophilum
: Biocatalyst in the Production of Sulfur and Organic Carbon from a Gas Stream Containing H
2
S and CO
2
Authors: Cork Douglas J. , Garunas Ruta , Sajjad Ashfaq
Published: January 2020

Chlorobium limicola
forma
thiosulfatophilum
(ATCC 17092) was grown in a 1-liter continuously stirred tank reactor (800-ml liquid volume) at pH 6.8, 30°C, saturated light intensity, and a gas flow rate of 23.6 ml/min from a gas cylinder blend consisting of 3.9 mol% H
2
S, 9.2 mol% CO
2
, 86.4 mol% N
2
, and 0.5 mol% H
2
. This is the first demonstration of photoautotrophic growth of a
Chlorobium
sp. on a continuous inorganic gas feed. A significant potential exists for applying this photoautotrophic process to desulfurization and CO
2
fixation of gases containing acidic components (H
2
S and CO
2
).
Grazing, Growth, and Ammonium Excretion Rates of a Heterotrophic Microflagellate Fed with Four Species of Bacteria
Authors: Sherr Barry F. , Sherr Evelyn B. , Berman Thomas
Published: January 2020

We studied aspects of the population growth of a microflagellate,
Monas
sp., isolated from Lake Kinneret, Israel. The protozoan growth rates, rates of ingestion of bacteria, and final population yields generally increased with increasing bacterial concentrations, although the exact relationship varied depending on the species of bacteria used as food. Grazing rates decreased hyperbolically with increasing food density. Gross growth efficiencies and ammonia excretion rates were similar over a range of food densities among the four species of bacteria. Population doubling times and ammonia excretion rates were lowest, and growth efficiencies were highest, at temperatures between 18 and 24°C. Under optimum conditions, the microflagellates had average population doubling times of 5.0 to 7.8 h, average growth efficiencies of 23.7 to 48.7%, and average ammonia excretion rates of 0.76 to 1.23 μmol of NH
4
+
per mg (dry wt) per h.
Microbial Transformation of Nitroaromatic Compounds in Sewage Effluent
Authors: Hallas Laurence E. , Alexander Martin
Published: January 2020

The transformation of mono- and dinitroaromatic compounds was measured in sewage effluent maintained under aerobic or anaerobic conditions. Most of the nitrobenzene, 3- and 4-nitrobenzoic acids, and 3- and 4-nitrotoluenes and much of the 1,2- and 1,3-dinitrobenzenes disappeared both in the presence and absence of oxygen. Under anaerobiosis, 2,6-dinitrotoluene and 3,5-dinitrobenzoic acid disappeared slowly, but no loss was evident in 28 days in aerated sewage. Aromatic amines did not accumulate during the aerobic decomposition of the mononitro compounds. They did appear in nonsterile, but not in sterile, sewage incubated aerobically with the dinitro compounds and anaerobically with all the chemicals. Analysis by gas chromatography and combined gas chromatography-mass spectrometry showed that aniline was formed from nitrobenzene, toluidine was formed from 3- and 4-nitrotoluenes, and aminobenzoic acid was formed from 3- and 4-nitrobenzoic acids under anaerobiosis, and that nitroaniline was formed from 1,2- and 1,3-dinitrobenzenes, aminonitrotoluene resulted from 2,6-dinitrotoluene, and aminonitrobenzoic acid was a product of 3,5-dinitrobenzoic acid under both conditions. The isomeric forms of the metabolites were not established. Aniline, 4-toluidine, and 4-aminobenzoic acid added to sewage disappeared from aerated nonsterile, but not from sterile, sewage or sewage in the absence of oxygen. 2-Nitroaniline, 2-amino-3-nitrotoluene, and 2-amino-5-nitrobenzoic acid added to sewage persisted for at least 60 days in aerobic or anaerobic conditions. Gas chromatographic and gas chromatographic-mass spectrometric analyses demonstrated that acetanilide and 2-methylquinoline were formed from aniline, 4-methylformanilide and 4-methylacetanilide were formed from 4-toluidine, 2-methylbenzimidazole was a product of 2-nitroaniline, and unidentified benzimidazoles were formed from 2-amino-3-nitrotoluene in the absence of oxygen, and that 2-nitroacetanilide and 2-methyl-6-nitroacetanilide were formed from 2-nitroaniline and 2-amino-3-nitrotoluene, respectively, in the presence or absence of oxygen. It is suggested that the transformations of widely used nitroaromatic compounds should be further studied because of the persistence and possible toxicity of products of their metabolism.
Ability of
Daphnia
Cell-Free Extract to Damage
Escherichia coli
Cells
Authors: Hadas Ora , Kott Yehuda , Bachrach Uriel , Cavari Benzion
Published: January 2020

A cell-free extract of
Daphnia magna
was found to lyse
Escherichia coli
cells as shown by leakage of the enzymes alkaline phosphatase and β-galactosidase from the bacteria. The cell-free extract was separated on Sephadex G-200, and the fractions showing an ability to lyse
E. coli
cels were isolated. The factor which was responsible for the lysis of the bacterial cells was probably a protein with a molecular weight of several thousands. Mg
2+
and Ca
2+
ions augmented the activity of the
Daphnia
extract on
E. coli
cells.
Net positives: conservative approach to measurement of proportions positive in substerilization process studies
Authors: Doolan P T , Halls N A , Joyce T M , Tallentire A
Published: January 2020

A method (designated the net positive approach) is described for scoring results of sterility tests done with more than one recovery condition on product items treated with inactivating agents at levels less than those used in sterilization processes proper (subprocess treatments). Three tests of sterility, one per recovery condition, constitute a single sample. A growth in one or more recovery conditions is scored as a net positive for that sample. The net positive approach reduces the occurrence of false-negatives and assigns a value to the proportion of items reported as nonsterile (proportions positive) that is conservative.
Transformations of 1- and 2-carbon halogenated aliphatic organic compounds under methanogenic conditions
Authors: Bouwer E J , McCarty P L
Published: January 2020

Several 1- and 2-carbon halogenated aliphatic organic compounds present at low concentrations (less than 100 micrograms/liter) were degraded under methanogenic conditions in batch bacterial cultures and in a continuous-flow methanogenic fixed-film laboratory-scale column. Greater than 90% degradation was observed within a 2-day detention time under continuous-flow methanogenic conditions with acetate as a primary substrate. Carbon-14 measurements indicated that chloroform, carbon tetrachloride, and 1,2-dichloroethane were almost completely oxidized to carbon dioxide, confirming removal by biooxidation. The initial step in the transformations of tetrachloroethylene and 1,1,2,2-tetrachloroethane to nonchlorinated end products appeared to be reductive dechlorination to trichloroethylene and 1,1,2-trichloroethane, respectively. Transformations of the brominated aliphatic compounds appear to be the result of both biological and chemical processes. The data suggest that transformations of halogenated aliphatic compounds can occur under methanogenic conditions in the environment.
Proposed role of lactate in germination of hypochlorite-treated Clostridium botulinum spores
Authors: Foegeding P M , Busta F F
Published: January 2020

Clostridium botulinum 12885A spores treated with hypochlorite required added DL-calcium lactate for L-alanine germination. Lactate was the active component of calcium lactate. Equimolar concentrations of L-malate, but not of DL-propionate, could replace lactate, suggesting that the alpha-hydroxy acid structure is important. Neither lactate nor malate was an effective germinant for buffer-treated or hypochlorite-treated spores. If the L-alanine concentration was increased 100-fold (to 450 mM), the lactate germination requirement was overcome. The data suggest that the L-alanine germination sites were modified by hypochlorite so that a higher concentration of alanine was required for activity. Lactate appeared to be an activator of modified or non-hypochlorite-modified L-alanine germination sites.
Aggregate Stabilization of Volcanic Ash and Soil During Microbial Degradation of Straw
Authors: Lynch J. M. , Elliott L. F.
Published: January 2020

Bacterial and fungal colonists of straw in soil promoted aggregate stabilization of volcanic ash and soil.
Amplification of D-xylose and D-glucose isomerase activities in Escherichia coli by gene cloning
Authors: Wovcha M G , Steuerwald D L , Brooks K E
Published: January 2020

A recombinant plasmid, designated pUC1002, was constructed by ligation of a HindIII restriction endonuclease fragment of Escherichia coli chromosomal DNA to vector plasmid pMB9. Strains carrying this plasmid were selected by transformation of an E. coli strain bearing the xyl-7 mutation to a xylose-positive (Xyl+) phenotype. Strains containing pUC1002 produced coordinately elevated levels of D-xylose isomerase and D-xylulose kinase. Under appropriate conditions, the isomerase also efficiently catalyzed the conversion of D-glucose to D-fructose.
Regiochemistry of Camphor Analog Oxidation by
Pseudomonas putida
Authors: Banerjee Sujit , Dombrowski Anne E. , Scala Anthony J.
Published: January 2020

Pseudomonas putida
cooxidized norcamphor and pericyclocamphanone to hydroxylated and lactonized products during growth on camphor. Norcamphor was hydroxylated at the 5 position, similar to the corresponding process in camphor, but pericyclocamphanone was oxidized at the 6 position. We conclude that the regiochemistry of the hydroxylation may be substrate controlled.
Isolation of satratoxins from the bedding straw of a sheep flock with fatal stachybotryotoxicosis
Authors: Harrach B , Bata A , Bajmócy E , Benko M
Published: January 2020

During a period of several weeks, more than 100 sheep died at a Hungarian farm. The animals exhibited fleece loosing, and hemorrhaging was the most important autopsy finding. Pasteurella haemolytica was cultured from various organs. The bedding straw was abundantly covered with Stachybotrys atra, and removal of the straw stopped the disease. Methanol extraction of the bedding straw followed by solvent partitioning, column chromatography, preparative thin-layer chromatography, and high-pressure liquid chromatography led to the isolation of satratoxins G and H, which were characterized by thin-layer chromatography, high-pressure liquid chromatography, and mass spectroscopy. This is the first isolation and characterization of toxins from a field sample of material responsible for an outbreak of stachybotryotoxicosis.
Effect of Streptococcus faecalis BIO-4R on intestinal flora of weanling piglets and calves
Authors: Ozawa K , Yabu-uchi K , Yamanaka K , Yamashita Y , Nomura S , Oku I
Published: January 2020

The effect of oral administration of Streptococcus faecalis BIO-4R, an antibiotic-resistant lactic acid bacterium, on the intestinal flora of weanling piglets and cows reared on antibiotic-containing diet was investigated. Fourteen days after administration of the bacteria, the intestinal flora of the piglets was examined. Animals of the administered group had stabilized lactic flora such as bifidobacteria, streptococci, and lactobacilli, whereas most animals of control group had reduced lactic flora. On the other hand, abundant yeasts were detected from the cecum, colon, and feces of the control animals, but the levels were significantly lower in the animals given strain BIO-4R. The density of Salmonella in the intestine appeared to be reduced after the administration of strain BIO-4R. The number of BIO-4R cells was shown to be 10 times lower in the duodenum and jejunum than in the ileum, suggesting that strain BIO-4R might have grown transiently in the ileum. The similar trend toward stabilization of the lactic flora was also observed in cows after administration of BIO-4R. In addition, an antagonistic effect of the strain against yeasts and Salmonella was suggested. These findings indicate that the oral administration of strain BIO-4R is one of the useful methods whereby the potentially deleterious effect of antibiotics on the intestinal flora of farm animals may be minimized.
Microbiological Survey of Adirondack Lakes with Various pH Values
Authors: Boylen Charles W. , Shick Marcy O. , Roberts Deborah A. , Singer Robert
Published: January 2020

Nine high-altitude oligotrophic Adirondack lakes in upstate New York having water of pH 4.3 to 7.0 were surveyed for total bacterial numbers and possible adaptation of the microbial communities to environmental pH. The number of heterotrophic bacteria from water samples recoverable on standard plate count agar were low (10
1
to 10
3
per ml) for most of the lakes. Acridine orange direct counts were approximately two orders of magnitude higher than plate counts for each lake. Sediment aerobic heterotrophs recovered on standard plate count agar ranged from 1.4 × 10
4
to 1.3 × 10
6
per g of sediment. Direct epifluorescence counts of bacteria in sediment samples ranged from 3.0 × 10
6
to 1.4 × 10
7
per g. Low density values were consistent with the oligotrophic nature of all the lakes surveyed. There were no apparent differences in numbers of bacteria originally isolated at pH 5.0 and pH 7.0 between circumneutral lakes (pH > 6.0) and acidic lakes (pH < 5.0). Approximately 1,200 isolates were recultured over a range of pH from 3.0 to 7.0. Regardless of the original isolation pH (pH 5.0 or pH 7.0), less than 10% of the isolates grew at pH < 5.0. Those originally isolated at pH 5.0 also grew at pH 6.0 and 7.0. Those originally isolated at pH 7.0 preferred pH 7.0, with 98% able to grow at pH 6.0 and 44% able to grow at pH 5.0. A chi-square contingency test clearly showed (
P
< 0.005) that two distinct heterotrophic populations had been originally isolated at pH 5.0 and pH 7.0, although there is undoubtedly some overlap between the two populations.
Nitrous oxide production by Escherichia coli is correlated with nitrate reductase activity
Authors: Smith M S
Published: January 2020

Nitrous oxide production by Escherichia coli seems to result from the reduction of NO2- by NO3- reductase. This hypothesis is consistent with previous observations and with the observation that molybdenum was required for both NO3- reduction and N2O production. Several E. coli NO3- reductase mutants were assayed for both N2O-producing and NO3--reducing activity. The hypothesized role of NO3- reductase is supported by the correlation of these two activities. Nitrate reduction to NH4+ enhanced growth, but NO2- reduction to N2O apparently did not. Therefore, this process differs significantly from respiratory denitrification.
Longevity of Salmonella typhimurium in Tilapia aurea and water from pools fertilized with swine waste
Authors: Baker D A , Smitherman R O , McCaskey T A
Published: January 2020

Salmonella typhimurium declined rapidly when inoculated into Tilapia aurea culture pools fertilized with fresh swine waste. Within the water column, a 95% decline of viable cells occurred during the first 6 h. Isolation of viable salmonellae was possible at 16 days post-inoculation, but not at 32 days. Similarly, salmonellae could be detected in the viscera and epithelium of T. aurea at 16 days, although not at 32 days. Salmonellae were not isolated from the fish flesh, nor was there evidence of septicemic infection.
Novel Haloperoxidase Reaction: Synthesis of Dihalogenated Products
Authors: Geigert John , Neidleman Saul L. , Dalietos Demetrios J. , DeWitt Susanne K.
Published: January 2020

The enzymatic synthesis of vicinal, dihalogenated products from alkenes and alkynes is described. The enzymatic reaction required an alkene or alkyne, dilute hydrogen peroxide, a haloperoxidase, and molar amounts of halide ions. Vicinal dichloro, dibromo, and diiodo products could be formed. A hydroxyl group on the carbon adjacent to the carbon-carbon double or triple bond lowered the halide ion concentration needed to produce the dihalo product. This reaction offers one explanation for the origin of natural, vicinal, dihalogenated products, such as those found frequently in marine microogranisms.
Detoxification of 2,4,5-trichlorophenoxyacetic acid from contaminated soil by Pseudomonas cepacia
Authors: Kilbane J J , Chatterjee D K , Chakrabarty A M
Published: January 2020

The strain of Pseudomonas cepacia, AC1100, capable of utilizing 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as a sole source of carbon and energy can degrade 2,4,5-T in contaminated soil, removing more than 99% of 2,4,5-T present at 1 mg/g of soil within 1 week. Repeated application of AC1100 even allowed more than 90% removal of 2,4,5-T within 6 weeks from heavily contaminated soil containing as much as 20,000 ppm 2,4,5,-T (20 mg/g of soil). Microbial removal of 2,4,5-T allowed the soil to support growth of plants sensitive to low concentrations of 2,4,5-T. After 2,4,5-T removal, the titer of AC1100 in the soil rapidly fell to undetectable levels within a few weeks.
Oxidation of Two Hydroxylated Ochratoxin A Metabolites by Alcohol Dehydrogenase
Authors: Syvertsen Christian , Størmer Fredrik C.
Published: January 2020

(4
R
)-4-hydroxyochratoxin A, (4
S
)-4-hydroxyochratoxin A, and 10-hydroxyochratoxin A, all formed from ochratoxin A, were incubated with alcohol dehydrogenase in the presence of NAD. Only (4
R
)-4-hydroxyochratoxin A and 10-hydroxyochratoxin A acted as substrates for the enzyme.

K
m

and turnover number for 10-hydroxyochratoxin A were 110 μM and 0.1 s
−1
, respectively.
Isolation of the Siderophore Schizokinen from Soil of Rice Fields
Authors: Akers Hugh A.
Published: January 2020

Schizokinen, a siderophore previously isolated from low-iron cultures of
Bacillus megaterium
and
Anabaena
sp., was isolated from the soil of rice fields after the annual flooding period.
Distribution of heterogeneous and homologous plasmids in Bacillus spp
Authors: Yoshimura K , Yamamoto O , Seki T , Oshima Y
Published: January 2020

A total of 75 strains (including 5 reference strains) of Bacillus amyloliquefaciens, B. cereus, B. circulans, B. licheniformis, B. megaterium, B. pumilus, B. sphaericus, B. subtilis, and B. thuringiensis and 36 species-unidentified Bacillus strains were surveyed for plasmids by cesium chloride-ethidium bromide equilibrium centrifugation of cell lysates in a study of antibiotic resistance in host cells. Of the 111 strains, 13 (including 3 reference strains) were found to harbor plasmids, and 5 of the 13 showed antibiotic resistance. This antibiotic resistance appeared not to be due to the plasmids, however, because the trait was not cured by cultivation of cells in nutrient medium containing ethidium bromide (1 microgram/ml), sodium dodecyl sulfate (0.2 micrograms/ml), or novobiocin (1 microgram/ml), except in one strain, in which kanamycin and streptomycin resistances were cured by novobiocin. One strain of B. amyloliquefaciens, S294, was found to harbor a plasmid, pFTB14, which differed from the plasmid species of classes 1 to 6 in B. subtilis and B. amyloliquefaciens, as determined by restriction analysis and DNA contour length determination. However, in DNA-DNA hybridization on a filter after Southern blotting from an agarose gel, the pFTB14 DNA hybridized with plasmids of classes 1 to 5. Three strains of B. thuringiensis each carried at least 4 to 11 plasmid species, whereas no plasmids were detected in four strains of B. cereus, which, in relation to B. thuringiensis, is closely related taxonomically and has highly homologous DNA sequences. The plasmid DNAs prepared from species other than B. subtilis and B. amyloliquefaciens did not hybridize with that of pFTB14.
Heterotrophic Activity Throughout a Vertical Profile of Seawater and Sediment in Halifax Harbor, Canada
Authors: Novitsky James A.
Published: January 2020

The relative heterotrophic activity of marine microorganisms was determined at two sites by the heterotrophic uptake technique throughout the water column, the sediment-water interface, and the surface layer of sediment. In the water column, uptake was greatest at the surface and steadily decreased with depth. The percentage of the substrate that was respired also decreased with depth from 69 to 56%. The activity of the sediment-water interface was several orders of magnitude greater than that of the overlying water and twice that of the sediment immediately below. Hand-collected water samples carefully taken as close as 1 cm from the sediment-water interface had the same characteristically low activity as the bottom few meters of water. Microautoradiography with
3
H-labeled glucose, glutamic acid, or thymidine revealed a general decrease in the percentage of active cells with depth from 35 to <1%. The number of active cells in the interface and sediment averaged <10% of the total population. The data indicate that the sediment-water interface is the most active region in this system due to an increased number of active cells rather than an increased percentage of active cells or increased per-cell activity.
Effects of Carrier and Temperature on Survival of
Rhizobium
spp. in Legume Inocula: Development of an Improved Type of Inoculant
Authors: Kremer Robert J. , Peterson Harold L.
Published: January 2020

The effects of inoculant carrier, temperature, and storage period on the survival of
Rhizobium
strains were determined by plate count and most-probable-number analyses. Preliminary experiments showed that survival of rhizobia was affected by each of these factors and their interactions. Results of further studies indicated that six strains of rhizobia survived better at high temperatures when lyophilized and suspended in an oil carrier as compared to finely ground peat. The oil base inocula contained ca. 10
5
viable rhizobia per g after 56 days of incubation at 60°C, whereas peat base inocula contained ≤10 rhizobia per g. These results suggest that an oil carrier will protect rhizobia from rapid death at usually lethal high temperatures.
Enhancement of goldfish virus-2 in vitro replication by the pesticides carbaryl and toxaphene
Authors: Shea T B
Published: January 2020

Goldfish virus-2 replication was enhanced in vitro by pretreatment of CAR cells with subcytotoxic concentrations of carbaryl and toxaphene. This phenomenon was time and temperature dependent. Shortening of pretreatment with carbaryl eliminated enhancement, which was observed for toxaphene only with substantially increased concentrations. Decreasing the temperature of pretreatment (4 degrees C) abrogated any enhancement by carbaryl and resulted in enhancement by toxaphene only at increased concentrations. Increased absorption of input virus was ruled out as a mechanism for enhancement, as was stimulation of cell division in the presence of pesticides over that of control cultures. Pretreatment of virus rather than cells did not result in enhancement.
Genetic recombination in Actinoplanes brasiliensis by protoplast fusion
Authors: Palleroni N J
Published: January 2020

Protoplast formation, fusion, and cell regeneration have been achieved with mutant strains of Actinoplanes brasiliensis. Three-, four-, and five-factor crosses have shown genetic recombination among the markers, and a five-factor cross is analyzed and discussed. Possibilities of using protoplast fusion for gene mapping and strain improvement are suggested.
Generalized Transduction in the Phytopathogen
Pseudomonas syringae
Authors: Nordeen Russell O. , Currier Thomas C.
Published: January 2020

Bacteriophages isolated from culture supernatants of
Pseudomonas syringae
pv.
syringae
and from sewage transferred various chromosomal genes to
P. syringae
PS224. Linkage between arginine and tryptophan loci was demonstrated. The number of transductants recovered per milliliter was not altered appreciably by UV irradiation of selected phage isolates. In addition, the presence of the IncP2 plasmid R38 in a
P. syringae
PS224 arginine auxotroph did not increase the transduction frequency as it does in
Pseudomonas aeruginosa.
Increasing the multiplicity of infection of transducing phage Pssy15 from 1 to 10 resulted in up to a 10-fold increase in the number of transductants recovered, although the actual transductional frequency remained about the same. Treatment of transduction mixtures with DNase did not affect transductional frequency.
Enumeration and Localization of N
2
-Fixing Bacteria Associated with Roots of
Spartina alterniflora
Loisel
Authors: McClung C. Robertson , van Berkum Peter , Davis Robert E. , Sloger Charles
Published: January 2020

Numbers and possible locations of N
2
-fixing bacteria were investigated in roots of
Spartina alterniflora
Loisel, which support nitrogenase activity in the undisturbed native habitat. N
2
-fixing bacteria were recovered in cultures both from
S. alterniflora
roots and from the surrounding sediment, and they formed a greater proportion of the bacteria recovered from root homogenates than from salt-marsh sediment. N
2
-fixing bacteria were recovered in high numbers from the rhizoplane of
S. alterniflora
after roots were treated with 1 or 5% chloramine-T for 1 h or with 1% NaOCl for 1 or 2 h. Immersing
S. alterniflora
roots in 5% NaOCl for 1 h was more effective in distinguishing bacteria inside the roots since this treatment nearly eliminated N
2
-fixing bacteria recoverable from the rhizoplane, although high numbers of N
2
-fixing bacteria were recovered from homogenates of roots treated with 5% NaOCl for 1 h. However, this treatment was less effective with roots of
Zea mays
L. (Funks G4646) and
Sorghum bicolor
(L.) Moench (CK-60 A), indicating that techniques to surface sterilize roots should be evaluated for different plants. Bacteria were observed by light and electron microscopy inter- and intracellularly in the cortex and in the aerenchyma of
S. alterniflora
roots. This study clearly shows that bacteria, including N
2
fixers, colonize the interior of roots of
S. alterniflora
growing in a Chesapeake Bay, Maryland, salt marsh.
Galactose Fermentation and Classification of Thermophilic Lactobacilli
Authors: Turner Keith W. , Martley F. G.
Published: January 2020

The ability to ferment galactose is a major characteristic which can be used to differentiate
Lactobacillus helveticus
(galactose positive) from
Lactobacillus lactis
and
Lactobacillus bulgaricus
(galactose negative). In milk cultures, galactose-positive strains produced
d
- and
l
-lactic acid with little galactose accumulation, whereas galactose-negative strains produced
d
-lactic acid, and galactose accumulated to high levels.
Microbiological Reduction of Quininone to Quinidine
Authors: Ray Lalitagauri , Gupta Chaitali Das , Majumdar S. K.
Published: January 2020

A yeast identified as
Hansenula anomala
var.
schneggii
was found capable of reducing quininone to quinidine in 50% yields in 7 days of fermentation.
Inactivation of Indigenous Viruses in Raw Sludge by Air Drying
Authors: Brashear David A. , Ward Richard L.
Published: January 2020

Air drying of raw sludge caused inactivation of indigenous viruses. A gradual loss of infectivity occurred with the loss of water until the solids content reached about 80%. A more rapid decline of viral infectivity occurred with further dewatering.
Rapid assay for detection of microorganisms producing DNA-damaging metabolites
Authors: Mazza G
Published: January 2020

Microorganisms producing DNA-damaging metabolites (i.e., fungi and streptomycetes) were detected by the Bacillus subtilis rec assay with agar plugs from plates on which the microorganisms had been grown. This assay allowed rapid identification of aflatoxinogenic fungi and streptomycetes producing strong DNA-damaging metabolites. For screening programs, several media have to be used to grow the microorganisms to be tested.
l
-Tryptophan Production by
Achromobacter liquidum
Authors: Ujimaru Toshihiko , Kakimoto Toshio , Chibata Ichiro
Published: January 2020

Conditions for the production of tryptophanase from
Achromobacter liquidum
and for the conversion of
l
-serine and indole to
l
-tryptophan were studied. The enzyme could be produced in amounts as great as 0.750 U/ml (degradation) and 0.294 U/ml (synthesis) by shaking cultures at 30°C in a medium containing dextrin, yeast extract,
l
-tryptophan, and
l
-glutamic acid.
l
-Tryptophan was produced most efficiently by shaking the cells at 37°C in a reaction mixture containing 60 mg of
l
-serine per ml, 60 mg of indole per ml, and 0.5 mM pyridoxal phosphate. After 3 days, 96 mg of
l
-tryptophan per ml was formed, and
l
-tryptophan was easily isolated to 85.4% yield by concentration of the reaction mixture.
Microcosm and Experimental Pond Evaluation of Microbial Community Response to Synthetic Oil Contamination in Freshwater Sediments
Authors: Sayler G. S. , Perkins R. E. , Sherrill T. W. , Perkins B. K. , Reid M. C. , Shields M. S. , Kong H. L. , Davis J. W.
Published: January 2020

A multivariate approach was used to evaluate the significance of synthetic oil-induced perturbations in the functional activity of sediment microbial communities. Total viable cell densities, ATP-biomass, alkaline phosphatase and dehydrogenase activity, and mineralization rates of glucose, protein, oleic acid, starch, naphthalene, and phenanthrene were monitored on a periodic basis in microcosms and experimental ponds for 11 months, both before and after exposure to synthetic oil. All variables contributed to significant discrimination between sediment microbial responses in control communities and communities exposed to a gradient of synthetic oil contamination. At high synthetic oil concentrations (4,000 ml/12 m
3
), a transient reduction in sediment ATP concentrations and increased rates of oleic acid mineralization were demonstrated within 1 week of exposure. These transient effects were followed within 1 month by a significant increase in rates of naphthalene and phenanthrene mineralization. After initial construction, both control and synthetic oil-exposed microbial communities demonstrated wide variability in community activity. All experimental microbial communities approached equilibrium and demonstrated good replication. However, synthetic oil perturbation was demonstrated by wide transient variability in community activity. This variability was primarily the result of the stimulation of polyaromatic hydrocarbon mineralization rates. In general, microcosms and pond communities demonstrated sufficient resiliency to recover from the effects of synthetic oil exposure within 3 months, although polyaromatic hydrocarbon mineralization rates remained significantly elevated.
Alkalotolerance of Yersinia enterocolitica as a basis for selective isolation from food enrichments
Authors: Schiemann D A
Published: January 2020

Alkalotolerance of Yersinia enterocolitica measured in solutions of potassium hydroxide with 0.5% sodium chloride was influenced by the cell suspension medium, temperature, and growth phase. The rate of cell destruction (delta log N per minute) was five times greater at 30 degrees C than at 20 degrees C. Differences in the degree of cell destruction at various concentrations of potassium hydroxide were related to pH and not to osmolarity. The addition of peptones to potassium hydroxide provided a protective effect that was greater for cells suspended in Trypticase soy broth than for those suspended in phosphate-buffered sorbitol-bile salts broth. Log-phase cells were less alkalotolerant than cells in the stationary phase of growth. A modified procedure for alkali treatment, using peptone-supplemented 0.5% potassium hydroxide-0.5% sodium chloride and the addition of a pH 6.6 buffer after treatment to prevent further cell destruction, was used to observe a marked difference in alkalotolerance between Y. enterocolitica and other gram-negative bacteria. Despite this difference, alkali treatment was not highly successful for recovery of Y. enterocolitica from enrichments of seeded foods in comparison with selective enrichment in bile-oxalate-sorbose broth.
Bacteria and Acidic Drainage from Coal Refuse: Inhibition by Sodium Lauryl Sulfate and Sodium Benzoate
Authors: Dugan Patrick R. , Apel William A.
Published: January 2020

The application of an aqueous solution of sodium lauryl sulfate and sodium benzoate to the surface of high-sulfur coal refuse resulted in the inhibition of iron-and sulfur-oxidizing chemoautotrophic bacteria and in the decrease of acidic drainage from the refuse, suggesting that acid drainage can be abated in the field by inhibiting iron- and sulfur-oxidizing bacteria.
Increased production of alpha-amylase by Bacillus amyloliquefaciens in the presence of glycine
Authors: Zhang Q , Tsukagoshi N , Miyashiro S , Udaka S
Published: January 2020

The production of alpha-amylase by Bacillus amyloliquefaciens increased by a factor of 300 when glycine was added to a chemically defined simple medium at the early-logarithmic phase of growth. Glycine was not metabolized to a significant extent under the conditions used, but it considerably prevented the lowering of the pH of the culture.
Anaerobic biodegradation of phenolic compounds in digested sludge
Authors: Boyd S A , Shelton D R , Berry D , Tiedje J M
Published: January 2020

We examined the anaerobic degradation of phenol and the ortho, meta, and para isomers of chlorophenol, methoxyphenol, methylphenol (cresol), and nitrophenol in anaerobic sewage sludge diluted to 10% in a mineral salts medium. Of the 12 monosubstituted phenols studied, only p-chlorophenol and o-cresol were not significantly degraded during an 8-week incubation period. The phenol compounds degraded and the time required for complete substrate disappearance (in weeks) were: phenol (2), o-chlorophenol (3), m-chlorophenol (7), o-methoxyphenol (2), m- and p-methoxyphenol (1), m-cresol (7), p-cresol (3), and o-, m-, and p-nitrophenol (1). Complete mineralization of phenol, o-chlorophenol, m-cresol, p-cresol, o-nitrophenol, p-nitrophenol, and o-, m-, and p-methoxyphenol was observed. In general, the presence of Cl and NO2 groups on phenols inhibited methane production. Elimination or transformation of these substituents was accompanied by increased methane production, o-Chlorophenol was metabolized to phenol, which indicated that dechlorination was the initial degradation step. The methoxyphenols were transformed to the corresponding dihydroxybenzene compounds, which were subsequently mineralized.
Fungal Biodegradation and Biotransformation of Soluble Lignocarbohydrate Complexes from Straw
Authors: Milstein Oleg A. , Vered Yaffa , Sharma Anil , Gressel Jonathan , Flowers Harold M.
Published: January 2020

Aspergillus japonicus
is an efficient degrader of phenolics and carbohydrates present in a mixture of soluble lignocarbohydrate complexes extracted from wheat straw.
Trichoderma
sp. attacked part of the carbohydrate but hardly affected the aromatic portion of this solution.
Polyporus versicolor
had a complex effect; polymerization of low-molecular-size phenolics accompanied the degradation of aromatic and carbohydrate polymers. The addition of xylose to the medium facilitated depolymerization of lignin by the fungi tested and prevented the polymerization of low-molecular-size fractions of lignocarbohydrate complexes by
P. versicolor. P. versicolor
, in contrast to
A. japonicus
and
Trichoderma
sp., also excreted into the medium considerable amounts of laccase, but only in the absence of endogenous or exogenous carbohydrates. Apparently, laccase is involved in polymerization rather than degradation of lignin in this organism. A number of extracellular glycanases were also secreted by these fungi.
Heat-stable proteases from psychrotrophic pseudomonads: comparison of immunological properties
Authors: Jackman D M , Bartlett F M , Patel T R
Published: January 2020

A heat-stable extracellular protease from Pseudomonas fluorescens was purified by chromatography on a DEAE-cellulose column and gel filtration on a Sephadex G100 column. The homogeneous enzyme preparation was used to prepare antiserum in rabbits. The rabbit antiserum was used to study the antigenic relatedness of proteases from 19 psychrotrophic pseudomonads isolated from raw milk. The inhibition of the proteases by the antiserum and the gel precipitin reactions revealed similar antigenic determinants in proteases from different isolates. Rabbit antiserum to the purified protease gave precipitin bands with antigens (proteases) from 10 different isolates. However, the same antiserum did not inhibit the protease activity in cell extracts of isolates T10, T13, and T24. By determining serological cross-reactions, proteases from psychrotrophic pseudomonads were shown to be different from one another.
Neuraminidase in Bacteroides fragilis
Authors: Berg J O , Lindqvist L , Andersson G , Nord C E
Published: January 2020

A neuraminidase from Bacteroides fragilis was purified 542-fold by isoelectric focusing, adsorption chromatography on Affi-Gel 202, and gel filtration chromatography on Sephadex G-200. On isoelectric focusing the neuraminidase was resolved into three differently charged fractions with pI values of 6.8, 7.1, and 7.4. The major component of pI 7.1 was used for further purification. The purified enzyme had optimal activity at pH 6.4 with N-acetylneuraminlactose as the substrate. Its molecular weight, determined by Sephadex G-200 gel filtration chromatography, was 92,000. The neuraminidase hydrolyzed terminal neuraminic acid residues from N-acetylneuraminlactose, fetuin, bovine submaxillary mucin, and porcine stomach lining mucin. A new method for the detection of neuraminidase activity is described which is based on rocket affinoelectrophoresis. It utilizes the differences in the interaction of sialylated and desialylated mucin with Helix pomatia lectin, enzymatic activity being detected by formation of affinorockets after incubation of the neuraminidase with bovine submaxillary mucin.
Conservation in Soil of H
2
Liberated from N
2
Fixation by Hup
-
Nodules
Authors: La Favre J. S. , Focht D. D.
Published: January 2020

Pigeon peas (
Cajanus cajan
) were grown in large soil columns (90-cm length by 30-cm diameter) and inoculated with four different strains of cowpea rhizobia, which varied with respect to hydrogen uptake activity (Hup). Despite the profuse liberation of H
2
from Hup
-
nodules in vitro, H
2
gas was not detected in any of the soil columns. When H
2
was injected into the columns, the rates of consumption were highest in the treatments (including control) containing Hup
-
nodules (218 and 177 nmol � h
−1
� cm
−2
) and lowest in the Hup
+
treatments (158, 92, and 64 nmoles � h
−1
� cm
−2
). In situ H
2
uptake rates in small soil cores at fixed distances from the nodules decreased exponentially with distance from the nodule (
R
2
= 0.99). This decrease in H
2
consumption was associated with a similar decrease in numbers of H
2
-oxidizing chemolithotrophic bacteria as determined by the most-probable-number method. On the basis of two equations derived separately upon diffusive theory (Fix's Law) and kinetic theory (Michaelis-Menten), the empirically derived rate constants and coefficients indicated that all of the H
2
emitted from Hup
-
nodules would be consumed by H
2
-oxidizing bacteria within a 3- to 4.5-cm radius of the nodule surface. It is concluded that H
2
is not lost from the soil-plant ecosystem during N
2
fixation in
C. cajan
but is conserved by H
2
-oxidizing bacteria.
Incidence of bacterial enteropathogens in foods from Mexico
Authors: Wood L V , Ferguson L E , Hogan P , Thurman D , Morgan D R , DuPont H L , Ericsson C D
Published: January 2020

We examined food consumption patterns of U.S. students temporarily living in Guadalajara, Mexico. Consumption of foods prepared in Mexican homes was associated with an increased risk of acquisition of diarrhea. Foods from commercial sources and private Mexican homes in Guadalajara were subsequently examined for contamination with coliforms, fecal coliforms, and bacterial enteropathogens. For comparison, selected restaurant foods were obtained in Houston, Tex. Food obtained from Mexican homes showed generally higher counts of coliforms and fecal coliforms than those obtained from commercial sources in Mexico and Houston. The foods in Mexico, both from homes and commercial sources, commonly contained Escherichia coli and occasionally enterotoxigenic E. coli. Foods in Houston were not contaminated with E. coli or enterotoxigenic E. coli. Salmonella (17 isolates), Shigella (4 isolates), and Aeromonas hydrophila (1 isolate) were found only in the foods obtained from Mexican homes. Enterotoxigenic non-E. coli Enterobacteriaceae was recovered with approximately equal frequency from all food sources.
Heat-stable protease from Pseudomonas fluorescens T16: purification by affinity column chromatography and characterization
Authors: Patel T R , Jackman D M , Bartlett F M
Published: January 2020

A heat-stable extracellular protease from Pseudomonas fluorescens T16, a psychrotroph, was purified by affinity column chromatography on a carbobenzoxy-D-phenylalanine-triethylene tetramine-Sepharose-4B column. The purified enzyme is a monomer with a molecular weight of 38,905 +/- 2,000. In an analytical ultracentrifuge, the Schlieren profile revealed a single symmetrical peak. The sedimentation coefficient was estimated to be 3.93S. Alpha-casein was the preferred substrate, with a Km of 0.05 mM. Heating crude enzyme and purified enzyme in buffer at 50, 90, and 120 degrees C resulted in a rapid initial loss of more than 50% of the initial activity followed by a gradual inactivation which exhibited first-order kinetics. The activation energy for the hydrolysis of casein was calculated to be 3.2 kcal/mol (13.4 kJ/mol).