bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of resin disinfectants-I3 and -I5 on Giardia muris and Giardia lamblia
Authors: Marchin G L , Fina L R , Lambert J L , Fina G T
Published: January 2020

The resin-I5 column developed in our laboratories rendered aqueous suspensions containing up to 5 X 10(4) cysts of Giardia muris or Giardia lamblia per ml incapable of excystation. The inhibition of excystation was effective at both 4 and 25 degrees C. The addition of Na2S2O3 to column eluates containing cysts appeared to partially reverse the disinfectant action, and the reversal was more pronounced at 4 degrees C than at 25 degrees C. In contrast, the rapid removal of cysts from the column eluates by centrifugation and filtration or the use of other reductants, notably cysteine and glutathione, did not similarly reverse the disinfectant properties of the column. Based on these data, we suggest that the disinfecting agent is acquired by the cyst in its passage through the resin column and that either the disinfecting agent or its reaction can be partially and specifically neutralized by Na2S2O3. We hypothesize that the time between disinfectant acquisition and activity is a function of the thickness of the Giardia cyst wall and consequently takes longer at the lower temperature. Nevertheless, resin-I5 appears to inactivate a larger number of cysts in a shorter period of time with lower residual halogen levels than do agents of other published methods.
Purification and characterization of mucopolysaccharidase from an oral strain of Bacteroides sp
Authors: Taniguchi H , Fujimura S , Takeuchi K , Nakamura T
Published: January 2020

A mucopolysaccharidase in the cell extract of an oral strain of Bacteroides sp. was purified to homogeneity by ammonium sulfate precipitation, DEAE-cellulose column chromatography, gel filtration on Sephadex G-200, and isoelectric focusing. Specific activity increased 110-fold and recovery was 2%. The molecular weight was determined to be 89,000 by gel filtration, and the isoelectric point was 7.0. The optimum pH for the activity was 6.5. The enzyme was inactivated by heating at 60 degrees C for 5 min. The purified mucopolysaccharidase degraded hyaluronic acid more rapidly than chondroitin and chondroitin sulfate A and C. However, it had no activity against chondroitin sulfate B, heparin, and heparan sulfate. Since unsaturated disaccharides were derived from the enzyme substrate, this enzyme was considered to be a mucopolysaccharide lyase.
Growth of Bacteria in Inorganic Medium at Different Levels of Airborne Organic Substances
Authors: Geller Annette
Published: January 2020

Invasion rates of airborne organic substances into sterile mineral medium were compared by using flasks closed with cotton stoppers, silicone stoppers, and screw caps with Teflon gaskets. The resulting increases of dissolved organic carbon were 0.5, 0.2, and 0 mg/liter per week, respectively. The compounds supported the growth of lake water bacteria and a strain of
Pseudomonas fluorescens
. Growth rates were correlated to the permeability of the stoppers used. The measured input of organic carbon in the sterile mineral medium is considered to be a minimum value for the actual contribution of organic compounds by the air. Multiplication rates of the bacteria suggest that the organisms prevent the escape of volatile organic substances from the medium by rapid utilization. The steady nutrient supply through the air should be considered in growth experiments with bacteria at low concentrations of nutrients.
Corrected Version Distribution of Heterogeneous and Homologous Plasmids in
Bacillus
spp
Authors: Yoshimura Koji , Yamamoto Osami , Seki Tatsuji , Oshima Yasuji
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 μg/ml), sodium dodecyl sulfate (0.2 μg/ml), or novobiocin (1 μg/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.
Bacterial Decarboxylation of
o
-Phthalic Acids
Authors: Taylor Barrie F. , Ribbons Douglas W.
Published: January 2020

The decarboxylation of phthalic acids was studied with
Bacillus
sp. strain FO, a marine mixed culture ON-7, and
Pseudomonas testosteroni.
The mixed culture ON-7, when grown anaerobically on phthalate but incubated aerobically with chloramphenicol, quantitatively converted phthalic acid to benzoic acid. Substituted phthalic acids were also decarboxylated: 4,5-dihydroxyphthalic acid to protocatechuic acid; 4-hydroxyphthalic and 4-chlorophthalic acids to 3-hydroxybenzoic and 3-chlorobenzoic acids, respectively; and 3-fluorophthalic acid to 2-and 3-fluorobenzoic acids.
Bacillus
sp. strain FO gave similar results except that 4,5-dihydroxyphthalic acid was not metabolized, and both 3- and 4-hydroxybenzoic acids were produced from 4-hydroxyphthalic acid.
P. testosteroni
decarboxylated 4-hydroxyphthalate (to 3-hydroxybenzoate) and 4,5-dihydroxyphthalate but not phthalic acid and halogenated phthalates. Thus,
P. testosteroni
and the mixed culture ON-7 possessed 4,5-dihydroxyphthalic acid decarboxylase, previously described in
P. testosteroni
, that metabolized 4,5-dihydroxyphthalic acid and specifically decarboxylated 4-hydroxyphthalic acid to 3-hydroxybenzoic acid. The mixed culture ON-7 and
Bacillus
sp. strain FO also possessed a novel decarboxylase that metabolized phthalic acid and halogenated phthalates, but not 4,5-dihydroxyphthalate, and randomly decarboxylated 4-hydroxyphthalic acid. The decarboxylation of phthalic acid is suggested to involve an initial reduction to 1,2-dihydrophthalic acid followed by oxidative decarboxylation to benzoic acid.
Concentration of rotavirus and enteroviruses from blue crabs (Callinectes sapidus)
Authors: Seidel K M , Goyal S M , Rao V C , Melnick J L
Published: January 2020

A simple method for concentration and detection of rotavirus and enteroviruses in the blue crab is described. Virus was separated from tissue homogenates at pH 9.5, concentrated by adsorption to protein precipitates at pH 3.5, and recovered by elution of precipitates at pH 9.2. Test samples of 12 to 15 ml were produced from an initial 100 g of crab tissues. Cat-floc precipitation was used to remove sample toxicity for cell cultures. Recovery effectiveness averaged 52% with poliovirus 1, echovirus 7, and coxsackievirus B5 and 23% with rotavirus SA11.
Natural occurrence of the mycotoxin viomellein in barley and the associated quinone-producing penicillia
Authors: Hald B , Christensen D H , Krogh P
Published: January 2020

In a batch of barley associated with field cases of mycotoxic porcine nephropathy and containing ochratoxin A and citrinin, the mycoflora were isolated by parallel incubation at 10 and 25 degrees C. Subsequently, the isolated cultures were checked for production of nephrotoxins (xanthomegnin, viomellein, ochratoxin, and citrinin). The nephrotoxin producers, all isolated by incubation at 10 degrees C, were comprised of one culture of Penicillium viridicatum, five cultures of Penicillium cyclopium, and one culture of Penicillium crustosum, all producing xanthomegnin and viomellein. One culture of P. cyclopium produced citrinin. Viomellein was detected in the barley at a concentration of approximately 1 mg/kg. The method of analysis for xanthomegnin and viomellein included extraction with chloroform, partitioning in hexane-acetone, and thin-layer chromatographic separation and identification. The identity of the xanthomegnin and viomellein produced by the isolated fungi and of viomellein detected in the barley was supported by infrared spectroscopy. This is the first report of viomellein as a natural contaminant of foodstuffs.
Role of catabolite regulatory mechanisms in control of carbohydrate utilization by the rumen anaerobic fungus Neocallimastix frontalis
Authors: Mountfort D O , Asher R A
Published: January 2020

Neocallimastix frontalis PN-1 utilized the soluble sugars D-glucose, D-cellobiose, D-fructose, maltose, sucrose, and D-xylose for growth. L-Arabinose, D-galactose, D-mannose, and D-xylitol did not support growth of the fungus. Paired substrate test systems were used to determine whether any two sugars were utilized simultaneously or sequentially. Of the paired monosaccharides tested, glucose was found to be preferentially utilized compared with fructose and xylose. The disaccharides cellobiose and sucrose were preferentially utilized compared with fructose and glucose, respectively, an cellobiose was also the preferred substrate compared with xylose. Xylose was the preferred substrate compared with maltose. In further incubations, the fungus was grown on the substrate utilized last in the two-substrate tests. After moderate growth was attained, the preferred substrate was added to the culture medium. Inhibition of nonpreferred substrate utilization by the addition of the preferred substrate was taken as evidence of catabolite regulation. For the various combinations of substrates tested, fructose and xylose utilization was found to be inhibited in the presence of glucose, indicating that catabolite regulation was involved. No clear-cut inhibition was observed with any of the other substrate combinations tested. The significance of these findings in relation to rumen microbial interactions and competitions is discussed.
Growth and end product formation of two psychrotrophic Lactobacillus spp. and Brochothrix thermosphacta ATCC 11509T at different pH values and temperatures
Authors: Blickstad E
Published: January 2020

Lactobacillus viridescens, Lactobacillus sp. strain 173 (homofermentative), and Brochothrix thermosphacta ATCC 11509T were studied at different pH values and temperatures in aerobic and anaerobic batch cultures. The growth rates were higher in aerobic than in anaerobic cultures. L. viridescens grew faster at pH 5.8 than at pH 6.3, whereas the opposite was true for B. thermosphacta. Lactobacillus sp. strain 173 was inhibited in air or at 8 degrees C in anaerobic culture. B. thermosphacta did not grow in anaerobic culture at pH 5.3. The following variations in growth yields were found in the different environments studied: Lactobacillus sp. strain 173, 23 to 25 g (dry weight) per mol of glucose consumed; L. viridescens, 11 to 23 g/mol; B. thermosphacta, 16 to 38 g/mol. In air, L. viridescens produced D-lactic acid, ethanol, and acetic acid, whereas no acetic acid was produced anaerobically. Acetic acid and ethanol together constituted 41 to 48% of the total product yield irrespective of pH and temperature. Lactobacillus sp. strain 173 produced a racemic mixture of D- and L-lactic acid at pH 6.3, whereas the proportion of L-lactic acid was higher than that of D-lactic acid at pH 5.3. In air, product formation of B. thermosphacta varied from a domination of L-lactic acid to increasing yields of acetoin, acetic acid, 2,3-butanediol and isovaleric acid. The effect of pH and temperature on product formation was difficult to separate from the effect of O2 availability in aerobic cultures. However, it was indicated that more 2,3-butanediol and less acetoin were produced with a decreasing temperature.(ABSTRACT TRUNCATED AT 250 WORDS)
Reproduction of
Bacillus stearothermophilus
as a Function of Temperature and Pressure
Authors: Yayanos A. Aristides , Van Boxtel R. , Dietz Allan S.
Published: January 2020

The colony-forming ability and the rate of reproduction of
Bacillus stearothermophilus
were determined as a function of temperature and pressure. Colonies were formed between 39 and 70°C at atmospheric pressure and between 54 and 67°C at 45 MPa. Colonies did not form at 55.9 MPa. The rate of reproduction in broth cultures decreased with increasing pressure at all temperatures. The rate of reproduction diminished rapidly with pressure above 10.4 MPa. Therefore, increased hydrostatic pressure was not sufficient to enable
B. stearothermophilus
to function beyond the temperature limiting growth and reproduction at atmospheric pressure, and
B. stearothermophilus
should grow in naturally or artificially warmed regions of the deep sea, where the pressure is less than approximately 50 MPa, although growth rates would be low above 10 MPa.
Distribution, Population Dynamics, and Characteristics of Ice Nucleation-Active Bacteria in Deciduous Fruit Tree Orchards
Authors: Gross Dennis C. , Cody Yvonne S. , Proebsting Edward L. , Radamaker Gary K. , Spotts Robert A.
Published: January 2020

Deciduous fruit tree orchards located in the Pacific Northwest were surveyed over a 3-year period for the presence of ice nucleation-active (INA) bacteria. In the Yakima Valley, only about 30% of the fruit tree orchards contained INA bacteria (median population ca. 3 × 10
2
CFU/g [fresh weight]) in contrast to nearly 75% of the orchards in the Hood River Valley (median population ca. 5 × 10
3
CFU/g [fresh weight]). These INA populations ranged from less than 10 to over 10
6
CFU/g (fresh weight) of blossoms and, in Hood River Valley orchards, generally comprised over 10% of the total bacterial population. Populations of INA bacteria fluctuated during the year with highest levels developing on buds and flowers during the cool, wet spring, followed by a drop in populations during the warmer, drier, summer months and finally a gradual increase in the autumn. The INA bacteria persisted on dormant buds from which they again colonized young developing vegetative tissues. All INA bacteria were identified as
Pseudomonas syringae
. The frequency of ice nucleation at −5°C for these strains ranged from nearly every cell being INA to less than 1 in 10
7
cells. The median frequency of ice nucleation at −5°C was 10
4
cells per ice nucleus. The INA
P. syringae
strains from individual orchards were diverse with respect to bacteriocin typing and in ice nucleation frequency. The consistent absence of detectable INA bacteria or presence of low populations in most of the orchards surveyed during periods when critical temperatures (i.e., −2 to −5°C) were common indicated a limited role for INA bacteria in frost susceptibility of most Pacific Northwest orchards.
Production and properties of alpha-glucosidase from Lactobacillus acidophilus
Authors: Li K B , Chan K Y
Published: January 2020

Lactobacillus acidophilus IFO 3532 was found to produce only intracellular alpha-glucosidase (alpha-D-glucoside glucohydrolase; EC 3.2.1.20). Maximum enzyme production was obtained in a medium containing 2% maltose as inducer at 37 degrees C and at an initial pH of 6.5. The enzyme was formed in the cytoplasm and accumulated as a large pool during the logarithmic growth phase. Enzyme production was strongly inhibited by 4 microM CuSO4, 40 microM CoCl2, and beef extract; MnSO4 and the presence of proteose peptone and yeast extract in the medium greatly enhanced enzyme production. A 16.6-fold purification of alpha-glucosidase was achieved by (NH4)2SO4 fractionation and DEAE-cellulose column chromatography. The enzyme showed high specificity for maltose. The Km for alpha-p-nitrophenyl-beta-D-glucopyranoside was 11.5 mM, and the Vmax for alpha-p-nitrophenyl-beta-D-glucopyranoside hydrolysis was 12.99 mumol/min per mg of protein. The optimal pH and temperature for enzyme activity were 5.0 and 37 degrees C, respectively. The enzyme activity was inhibited by Hg2+, Cu2+, Ni2+, Zn2+, Ca2+, Co2+, urea, rose bengal, and 2-iodoacetamide, whereas Mn2+, Mg2+, L-cysteine, L-histidine, Tris, and EDTA stimulated enzyme activity. Transglucosylase activity was present in the partially purified enzyme, and isomaltose was the only glucosyltransferase product. Amylase activity in the purified preparation was relatively weak, and no isomaltase activity was detected.
Double-Staining Epifluorescence Technique to Assess Frequency of Dividing Cells and Bacteriovory in Natural Populations of Heterotrophic Microprotozoa
Authors: Sherr Evelyn B. , Sherr Barry F.
Published: January 2020

We have developed a double-staining procedure for use with epifluorescence microscopy which allows the detection both of dividing cells and of ingested bacteria in food vacuoles of heterotrophic microprotozoa. Microprotozoan cells are stained sequentially with the DNA-specific fluorochrome DAPI (4′,6-diami-dino-2-phenylindole) and the nonspecific protein stain fluorescein isothiocyanate. During microscopic examination, heterotrophic microprotozoan cells are first located with fluorescein isothiocyanate fluorescence and then epifluorescence filter sets are switched to permit inspection under DAPI fluorescence of the cell nuclei and of the contents of food vacuoles. Among in situ populations of estuarine microprotozoa sampled over a tidal cycle, we found from 2.2 to 5.2% of the heterotrophic cells in a recognizable stage of division (nuclei elongated or double). Batch culture growth experiments were also carried out both with natural populations and with two isolated species of estuarine microprotozoa. In these experiments, the frequency of dividing cells ranged from 1.2 to 3.8% and appeared to be negatively correlated with growth rate. Microprotozoan populations sampled in continental shelf waters off Savannah, Ga., had mean frequencies of dividing cells ranging from 2.0 to 5.0%. A large fraction of cells in heterotrophic microprotozoan populations (an average of 27.4 ± 1.0% in estuarine water and of 30.1 ± 4.8% in shelf water) had DAPI-stained inclusions, presumably recently ingested bacteria, in their food vacuoles.
Microbial Decomposition of Wood in Streams: Distribution of Microflora and Factors Affecting [
14
C]Lignocellulose Mineralization
Authors: Aumen Nicholas G. , Bottomley Peter J. , Ward G. Milton , Gregory Stan V.
Published: January 2020

The distribution and lignocellulolytic activity of the microbial community was determined on a large log of Douglas fir (
Pseudotsuga menziesii
) in a Pacific Northwest stream. Scanning electron microscopy, plate counts, and degradation of [
14
C]lignocelluloses prepared from Douglas fir and incubated with samples of wood taken from the surface and within the log revealed that most of the microbial colonization and lignocellulose-degrading activity occurred on the surface. Labeled lignocellulose and surface wood samples were incubated in vitro with nutrient supplements to determine potential limiting factors of [
14
C]lignocellulose degradation. Incubations carried out in a nitrogenless mineral salts and trace elements solution were no more favorable to degradation than those carried out in distilled water alone. Incubations supplemented with either (NH
4
)
2
SO
4
or organic nitrogen sources showed large increases in the rates of mineralization over incubations with mineral salts and trace elements alone, with the greatest effect being observed from an addition of (NH
4
)
2
SO
4
. Subsequent incubations with (NH
4
)
2
SO
4
, KNO
3
, and NH
4
NO
3
revealed that KNO
3
was the most favorable for lignin degradation, whereas all three supplements were equally favorable for cellulose degradation. Supplementation with glucose repressed both lignin and cellulose mineralization. The results reported in this study indicate that nitrogen limitation of wood decomposition may exist in streams of the Pacific Northwest. The radiotracer technique was shown to be a sensitive and useful tool for assessing relative patterns of lignocellulose decay and microbial activity in wood, along with the importance of thoroughly characterizing the experimental system before its general acceptance.
Heat injury in Staphylococcus aureus 196E: protection by metabolizable and non-metabolizable sugars and polyols
Authors: Smith J L , Benedict R C , Haas M , Palumbo S A
Published: January 2020

Polyols and sugars, which were not metabolized (O2 uptake or fermentation was not demonstrated), protected Staphylococcus aureus 196E against heat injury as well as metabolized compounds. Inhibitors of glucose metabolism decreased O2 uptake with glucose but did not affect the protective ability of glucose against heat injury.
Torulopsis petrophilum
and Surface Activity
Authors: Cooper David G. , Paddock David A.
Published: January 2020

Torulopsis petrophilum
can synthesize either a glycolipid surfactant or a protein emulsifier depending on the substrate used. These compounds were not produced to facilitate the uptake of an insoluble carbon source. The glycolipids produced were identical to the mixture isolated from
T. bombicola
.
Satellite growth of Legionella pneumophila with an environmental isolate of Flavobacterium breve
Authors: Wadowsky R M , Yee R B
Published: January 2020

Legionella pneumophila serogroup 1 was observed to satellite around colonies of Flavobacterium breve on an L-cysteine-deficient medium which did not support growth of legionellae. Both isolates were recovered from the hot water tanks of hospitals. Ferric PPi stimulated satellite growth between 0.01 and 0.1%.
Transformation of 1- and 2-methylnaphthalene by Cunninghamella elegans
Authors: Cerniglia C E , Lambert K J , Miller D W , Freeman J P
Published: January 2020

Cunninghamella elegans metabolized 1- and 2-methylnaphthalene primarily at the methyl group to form 1- and 2-hydroxymethylnaphthalene, respectively. Other compounds isolated and identified were 1- and 2-naphthoic acids, 5-hydroxy-1-naphthoic acid, 5-hydroxy-2-naphthoic acid, 6-hydroxy-2-naphthoic acid, and phenolic derivatives of 1- and 2-methylnaphthalene. The metabolites were isolated by thin-layer and reverse-phase high-pressure liquid chromatography and characterized by the application of UV-visible absorption, 1H nuclear magnetic resonance, and mass spectral techniques. Experiments with [8-14C]2-methylnaphthalene indicated that over a 72-h period, 9.8% of 2-methylnaphthalene was oxidized to metabolic products. The ratio of organic-soluble in water-soluble metabolites at 2 h was 92:8, and at 72 h it was 41:59. Enzymatic treatment of the 48-h aqueous phase with either beta-glucuronidase or arylsulfatase released 60% of the metabolites of 2-methylnaphthalene that were extractable with ethyl acetate. In both cases, the major conjugates released were 5-hydroxy-2-naphthoic acid and 6-hydroxy-2-naphthoic acid. The ratio of the water-soluble glucuronide conjugates to sulfate conjugates was 1:1. Incubation of C. elegans with 2-methylnaphthalene under an 18O2 atmosphere and subsequent mass spectral analysis of 2-hydroxymethylnaphthalene indicated that hydroxylation of the methyl group is catalyzed by a monooxygenase.
Round robin investigation of methods for the recovery of poliovirus from drinking water
Authors: Melnick J L , Safferman R , Rao V C , Goyal S , Berg G , Dahling D R , Wright B A , Akin E , Stetler R , Sorber C
Published: January 2020

Six laboratories actively involved in water virology research participated in a methods evaluation study, conducted under the auspices of the American Society for Testing and Materials Committee on Viruses in the Aquatic Environment, Task Force on Drinking Water. Each participant was asked to examine the Viradel (virus adsorption-elution) method with cartridge-type Filterite filters for virus adsorption and organic flocculation and aluminum hydroxide-hydroextraction for reconcentration. Virus was adsorbed to filter media at pH 3.5 and eluted with either glycine buffer (pH 10.5) or beef extract-glycine (pHG 9.0). Considerable variation was noted in the quantity of virus recovered from four 100-liter samples of dechlorinated tapwater seeded with low (350 to 860 PFU) and high (1,837 to 4,689 PFU) doses of poliovirus type 1. To have a more uniform standard of comparison, all the test samples were reassayed in one laboratory, where titers were also determined for the virus seed. Test results of the Viradel-organic flocculation method indicated that the average percentage of virus recovery for low-input experiments was 66%, with a range of 8 to 20% in two laboratories, 49 to 63% in three laboratories, and 198% in one laboratory. For the high-input experiments, two laboratories reported recoveries of 6 to 12%, and four laboratories reported recoveries of 26 to 46%. For the Viradel aluminum hydroxide-hydroextraction procedure, two laboratories recovered 9 to 11%, whereas four obtained 17 to 34% for low-input experiments. For the high-input tests, two laboratories reported a recovery of 3 to 5%, and four recovered 11 to 18% of the seeded virus.(ABSTRACT TRUNCATED AT 250 WORDS)
Location of Peptidases Outside and Inside the Membrane of
Streptococcus cremoris
Authors: Exterkate Fred A.
Published: January 2020

Peptidase activity determinations involving native cells of
Streptococcus cremoris
and completely disrupted cell preparations, as well as experiments concerned with peptidase activity distribution among cell fractions obtained by a damage-restrictive removal of the cell wall and release of intracellular material, suggest the presence of peptidases with distinguishable locations. Alanyl, leucyl, and prolyl aminopeptidase activities are most likely located in the cell wall-membrane interface, showing no detectable association with the membrane. Lysyl aminopeptidase is present not only in this location, but also as an intracellular enzyme. Endopeptidase activity and glutamate aminopeptidase activity appear to be weakly associated with the membrane. The locations of these two peptidase activities, unlike those of the former aminopeptidase activities, impose a restriction on their expression. Results of experiments concerned with permeabilization of the membrane and findings regarding an effect of the local environment of the enzymes on their pH activity profiles are evaluated and considered as being indicative of the proposed location. The possible implications of these findings with respect to protein utilization during growth of the organism in milk are discussed.
Effect of butanol on lipid composition and fluidity of Clostridium acetobutylicum ATCC 824
Authors: Vollherbst-Schneck K , Sands J A , Montenecourt B S
Published: January 2020

Butanol, at sub-growth-inhibitory levels, caused a ca. 20 to 30% increase in fluidity of lipid dispersions from Clostridium acetobutylicum. When grown in the presence of butanol or into stationary phase, C. acetobutylicum synthesized increased levels of saturated acyl chains at the expense of unsaturated chains.
Dialysis membrane technique for ultrastructural studies of microbial interactions
Authors: Nordbring-Hertz B , Veenhuis M , Harder W
Published: January 2020

A dialysis membrane technique was developed that enabled ultrastructural investigations of the interaction of nematode-trapping fungi and their nematode prey. It allowed the sectioning of individual traps that had been selected by light microscopy and was used in kinetic studies on trap formation, nematode capture, and subsequent nematode digestion. The method can also be used for enzyme cytochemical experiments.
Influence of temperature and water activity on growth and patulin production by Byssochlamys nivea in apple juice
Authors: Roland J O , Beuchat L R
Published: January 2020

The influence of temperature and water activity (aw) on growth and patulin production by Byssochlamys nivea in apple syrups was determined over a 44-day incubation period. The minimum aw at which the mold was capable of growing was 0.915 and 0.886 at 21 and 30 degrees C, respectively. Growth at 37 degrees C was observed at 0.871 aw. Minimum aw values for patulin production were 0.978, 0.968, and 0.959 at 21, 30 and 37 degrees C, respectively.
Response of marine bacterioplankton to differential filtration and confinement
Authors: Ferguson R L , Buckley E N , Palumbo A V
Published: January 2020

The bacterioplankton community of confined seawater at 25 degrees C changed significantly within 16 h of collection. Confinement increased CFU, total cell number (by epifluorescence microscopy), and average cell volume of bacterioplankton and increased the turnover rate of amino acids in seawater sampled at Frying Pan Shoals, N.C. The bacterioplankton community was characterized by two components: differential doubling times during confinement shifted dominance from bacteria which were nonculturable to bacteria which were culturable on a complex nutrient medium. Culturable cells (especially those of the genera Pseudomonas, Alcaligenes, and Acinetobacter) increased from 0.08% of the total cell number in the seawater immediately after collection to 13% at 16 h and 41% at 32 h of confinement. Differential filtration before confinement indicated that particles passing through a 3.9-microns-, but retained by a 0.2-micron-, pore-size Nuclepore filter may be a major source of primary amines to the confined population. The 3.0-microns filtration increased growth rate and ultimate numbers of culturable cells through the removal of bacterial predators or the release of primary amines from cells damaged during filtration or both.
Nodularia
(
Cyanobacteriaceae
) Akinetes in the Sediments of the Peel-Harvey Estuary, Western Australia: Potential Inoculum Source for
Nodularia
Blooms
Authors: Huber Ann L.
Published: January 2020

The populations of viable
Nodularia
(
Cyanobacteriaceae
) propagules in the sediments of the Peel-Harvey Estuary in Western Australia were assessed over location, time, and depth. The sediments of the Harvey Estuary had greater numbers of
Nodularia
propagules than those of the contiguous Peel Inlet. This was consistent with the distribution of
Nodularia
blooms in the system. The sediment populations of
Nodularia
propagules has increased up to 100-fold at the study sites over a 4-year period during which three blooms have occurred. It is considered that the majority of the propagules are akinetes. The significance of the sediment akinetes in providing the inoculum for rapid onset of
Nodularia
blooms is discussed. The population of akinetes decreased with depth, but viable akinetes were still found at 35 cm, the maximum depth sampled. Bioturbation by polychaete worms is likely to be significant in the distribution of akinetes to these depths.
Application of a Microcomputer-Based System to Control and Monitor Bacterial Growth
Authors: Titus Jeffrey A. , Luli Gregory W. , Dekleva Michael L. , Strohl William R.
Published: January 2020

A modular microcomputer-based system was developed to control and monitor various modes of bacterial growth. The control system was composed of an Apple II Plus microcomputer with 64-kilobyte random-access memory; a Cyborg ISAAC model 91A multichannel analog-to-digital and digital-to-analog converter; paired MRR-1 pH, pO
2
, and foam control units; and in-house-designed relay, servo control, and turbidimetry systems. To demonstrate the flexibility of the system, we grew bacteria under various computer-controlled and monitored modes of growth, including batch, turbidostat, and chemostat systems. The Apple-ISAAC system was programmed in Labsoft BASIC (extended Applesoft) with an average control program using ca. 6 to 8 kilobytes of memory and up to 30 kilobytes for datum arrays. This modular microcomputer-based control system was easily coupled to laboratory scale fermentors for a variety of fermentations.
Suppression of interferon synthesis by the pesticide carbaryl as a mechanism for enhancement of goldfish virus-2 replication
Authors: Shea T B , Berry E S
Published: January 2020

Interferon production was demonstrated by the goldfish-derived CAR cell line in response to infection by goldfish virus-2. Supernatants of infected cultures provided antiviral protection to CAR cells and another cell line derived from goldfish, ABIII. The protective factor retained activity after ultracentrifugation, dialysis, freezing and thawing, acid treatment (pH 2), or heating to 56 degrees C but was sensitive to trypsin. Supernatants of infected cultures did not affect adsorption of virus. Previous studies have shown that replication of goldfish virus type 2 is enhanced by pretreatment of cultures with subcytotoxic concentrations of carbaryl. In the present study, pesticide-treated cultures were found to synthesize reduced levels of interferon.
Genetic Construction of Lactose-Utilizing
Xanthomonas campestris
Authors: Walsh Patricia M. , Haas Michael J. , Somkuti George A.
Published: January 2020

Xanthomonas campestris
, the producer of xanthan gum, possesses a β-galactosidase of very low specific activity. Plasmid pGC9114 (RP1::Tn
951
), generated by the transposition of the lactose transposon Tn
951
to RP1, was conjugally transferred into XN1, a nalidixic acid-resistant derivative of
X. campestris
NRRL B-1459S-4L. Transfer occurred on membrane filters and in broth. The β-galactosidase gene of Tn
951
was expressed in
X. campestris
. The specific activity of β-galactosidase in transconjugants was over 200-fold higher than that in XN1, and transconjugants grew as well in lactose-based media as in glucose-based media. The lactose-utilizing transconjugants could potentially be used to produce xanthan gum from cheese whey.
Phosphate Nutrition of
Rhizobium
spp
Authors: Beck Douglas P. , Munns Donald N.
Published: January 2020

This study was conducted to determine the behavior of 40 strains from six species of
Rhizobium
in liquid defined media containing orthophosphate at levels likely to be encountered naturally, ranging from the high concentrations expected in nodules and artificial media to the low concentrations of soil solutions. Storage capacity in strains with high levels (2 mM) of P and ability to utilize this stored P for growth after transfer to low levels (0.06 μM) of P varied with each strain. Storage varied from about 1 to 2% P (dry weight) for all strains, with the number of generations supported dependent on the quantity of P stored and on the utilization efficiency. The ability to store P at high levels is probably less important than the uptake and utilization efficiency of P supplied at low levels. Strains varied greatly in tolerance to low levels of P maintained in solution by an iron oxide buffering system. Differences in growth rate at low levels of P were large enough to be agronomically important.
Development of a monoclonal antibody capable of interacting with five serotypes of Staphylococcus aureus enterotoxin
Authors: Meyer R F , Miller L , Bennett R W , MacMillan J D
Published: January 2020

A monoclonal antibody capable of binding to determinants shared in common by staphylococcal enterotoxin serotypes A, B, C1, D, and E was developed. To accomplish this, BALB/c mice were immunized by alternating injections of serotypes A and D to enrich for spleen lymphocytes programmed to produce antibody to possible common determinants. These cells, fused with mutant myeloma cells (P3-X-63Ag8.653) produced hybrids that formed monoclonal antibodies to either serotype A only or to both serotypes A and D. A cloned hybridoma from the latter group produced an antibody (subclass immunoglobulin G1) which interacted with five serotypes. Highest affinity was to B and C1. An immunomatrix consisting of this antibody cross-linked to protein A-Sepharose CL-4B with dimethyl pimelimidate was capable of binding enterotoxin. Bound toxin was eluted with diethylamine. Because of its ability to interact with all five serotypes, the monoclonal antibody should prove useful in the development of a rapid method for screening foods for the presence of staphylococcal enterotoxin.
Penetration of different human pathogenic viruses into sand columns percolated with distilled water, groundwater, or wastewater
Authors: Dizer H , Nasser A , Lopez J M
Published: January 2020

The adsorption of several enteroviruses and rotavirus SA11 to sand from an aquifer in the Federal Republic of Germany was estimated in sand-filled columns loaded with ca. 10(7) PFU and run at a velocity of 2.5 m/day for 12 h. After either distilled water, groundwater, secondary effluent, or tertiary effluent was percolated, the sand core was slowly extruded out of the column and cut in 1-cm slices. The slices were eluted with nutrient broth, and the amount of viruses in the broth was estimated. The best adsorption was promoted by groundwater and tertiary effluent, followed by distilled water and secondary effluent. Similar experiments, carried out at different percolation rates, indicated that a 50-day underground stay of recharged water probably suffices to eliminate viruses in the groundwater-recharged tertiary effluent. However, when viruses and sand were incubated in the presence of the surfactants sodium dodecyl sulfate, nonyl phenol, dodigen 226, or alkylbenzylsulfonate, the adsorption of the viruses was substantially diminished. Experiments in the presence of nonyl phenol seem to indicate that hydrophobic interactions are involved in the adsorption of viruses to sand.
Enhancement of Lignin Degradation in
Streptomyces
spp. by Protoplast Fusion
Authors: Pettey Thomas M. , Crawford Don L.
Published: January 2020

Protoplast fusion was investigated as a technique for genetically manipulating two lignin-degrading
Streptomyces
strains,
Streptomyces viridosporus
T7A and
Streptomyces setonii
75Vi2. Four of 19 recombinants tested showed enhanced production of acid-precipitable polymeric lignin (APPL), producing 155 to 264% more APPL from corn stover lignocellulose than was produced by the wild-type
S. viridosporus
T7A. APPLs are lignin degradation intermediates known to be potentially valuable chemical products produced by bioconversion of lignin with
Streptomyces
spp. The prospects of utilizing protoplast fusion to construct APPL-overproducing
Streptomyces
strains was considered especially promising.
The wood preservative chromated copper arsenate is a substrate for trimethylarsine biosynthesis
Authors: Cullen W R , McBride B C , Pickett A W , Reglinski J
Published: January 2020

The wood preservative chromated copper arsenate (CCA) is a very widely used product. As it contains both copper and arsenic, it is not dissimilar to the pigments Scheele's green and Schweinfurter's green which were found to be biologically convertible to the toxic Gosio gas (B. Gosio, Ber. 30:1024-1026, 1897) later identified by Challenger and co-workers as trimethylarsine (F. Challenger, Adv. Enzymol. 12:429-491, 1951). Thus, it was of interest to determine whether microbiological action on CCA and wood treated with CCA could result in the production of trimethylarsine. We report that the fungus Candida humicola will produce this arsine from dilute solutions of CCA and from wood soaked in CCA.
Physiological Studies of Oxygen Protection Mechanisms in the Heterocysts of
Anabaena cylindrica
Authors: Murry Marcia A. , Horne Alexander J. , Benemann John R.
Published: January 2020

The mechanism of O
2
protection of nitrogenase in the heterocysts of
Anabaena cylindrica
was studied in vivo. Resistance to O
2
inhibition of nitrogenase activity correlated with the O
2
tension of the medium in which heterocyst formation was induced. O
2
resistance also correlated with the apparent

K
m

for acetylene, indicating that O
2
tension may influence the development of a gas diffusion barrier in the heterocysts. The role of respiratory activity in protecting nitrogenase from O
2
that diffuses into the heterocyst was studied using inhibitors of carbon metabolism. Reductant limitation induced by 3-(3,4-dichlorophenyl)-1, 1-dimethylurea increased the O
2
sensitivity of in vivo acetylene reduction. Azide, at concentrations (30 mM) sufficient to completely inhibit dark nitrogenase activity (a process dependent on oxidative phosphorylation for its ATP supply), severely inhibited short-term light-dependent acetylene reduction in the presence of O
2
but not in its absence. After 3 h of aerobic incubation in the presence of 20 mM azide, 75% of cross-reactive component I (Fe-Mo protein) in nitrogenase was lost; less than 35% was lost under microaerophilic conditions. Sodium malonate and monofluoroacetate, inhibitors of Krebs cycle activity, had only small inhibitory effects on nitrogenase activity in the light and on cross-reactive material. The results suggest that oxygen protection is dependent on both an O
2
diffusion barrier and active respiration by the heterocyst.
Aflatoxin B1 dihydrodiol antibody: production and specificity
Authors: Pestka J J , Chu F S
Published: January 2020

A specific antibody for 2,3-dihydro-2,3-dihydroxyaflatoxin B1 (AFB1-diol) was prepared, and its reactivity was characterized for the major aflatoxin (AF) B1 (AFB1) metabolites. Reductive alkylation was used to conjugate AFB1-diol to ethylenediamine-modified bovine serum albumin (EDA-BSA) and horseradish peroxidase for use as an immunogen and an enzyme-linked immunosorbent assay (ELISA) marker, respectively. High reactant ratios, 1:5 and 1:10, for AFB1-diol-EDA-BSA (wt/wt) resulted in precipitated conjugates which were poorly immunogenic. However, a soluble conjugate obtained by using a 1:25 ratio of AFB1-diol to EDA-BSA could be used for obtaining high-titer AFB1-diol rabbit antibody within 10 weeks. Competitive ELISAs revealed that the AFB1-diol antibody detected as little as 1 pmol of AFB1-diol per assay. Cross-reactivity of AFB1-diol antibody in the competitive ELISA with AF analogs was as follows: AFB1-diol, 100%; AFB1, 200%; AFM1, 130%; AFB2a, 100%; AFG1, 6%; AFG2, 4%; aflatoxicol, 20%; AFQ1, 2%; AFB1-modified DNA, 32%; and 2,3-dihydro-2-(N7-guanyl)-3-hydroxy AFB1, 0.6%. These data indicated that the cyclopentanone and methoxy moieties of the AF molecule were the primary epitopes for the AFB1-diol antibody. The AFB1-diol competitive ELISA was subject to substantial interference by human, rat, and mouse serum albumins but not by BSA, Tris, human immunoglobulin G, or lysozyme. By using a noncompetitive, indirect ELISA with an AFB1-modified DNA solid phase, a modification level of one AFB1 residue for 200,000 nucleotides could be determined.
Disinfection of Water with Quaternary Ammonium Salts Insolubilized on a Porous Glass Surface
Authors: Nakagawa Yoshihiro , Hayashi Hiroyuki , Tawaratani Takahiko , Kourai Hiroki , Horie Tokunaru , Shibasaki Isao
Published: January 2020

Insoluble quaternary ammonium salts bound to porous glass showed antibacterial activity. An agent designated as G
12
, which had a dodecyl alkyl chain, was selected for some antibacterial tests on comparison of it with the agent reported previously. The antibacterial activity of G
12
toward
Escherichia coli
was mainly due to the adsorption of cells and therefore gradually decreased during continuous treatment of a cell suspension. The lost G
12
activity was completely recovered by washing with ethanol, and the activity of refreshed G
12
decreased in the same manner as that of fresh G
12
. The lost activity was, however, always recovered only by ethanol treatment. This indicated that G
12
might interact with cells more strongly by means of a hydrophobic force than an electrostatic one. The antimicrobial spectrum showed that G
12
was effective against not only bacteria but also yeasts.
Use of 31P nuclear magnetic resonance spectroscopy and electron microscopy to study phosphorus metabolism of microorganisms from wastewaters
Authors: Florentz M , Granger P , Hartemann P
Published: January 2020

We used 31P nuclear magentic resonance to study the transfer of phosphorus between Pis and polyphosphates in microorganisms involved in wastewater treatment. We showed that the transfer process is reversible and of the first order in accordance with the polyphosphate concentration. The presence of nitrates in the anoxic phase led to results similar to those obtained during the aerobic phase. (Anoxic implies absence of oxygen but presence of nitrate, whereas anaerobic implies absence of oxygen and nitrate. In bacteriology, the term anoxic is not common, and the term anaerobic implies absence of oxygen and includes the conditions under which nitrate is present.) We observed that carbon dioxide lowers the pH, which entails a hydrolysis of polyphosphates, and helium seems to stop the evolution of the cells. Further, 2,4-dinitrophenol decouples the oxidative phosphorylation and brings about a decrease in the polyphosphate pool.
Production and Characterization of Cellulase and β-Glucosidase from a Mutant of
Alternaria alternata
Authors: Macris Basil J.
Published: January 2020

A mutant of
Alternaria alternata
excreted enhanced levels of carboxymethylcellulase and particularly β-glucosidase when grown in cellulose liquid media. Both enzymes were purified two- to four-fold by ammonium sulfate precipitation and gel filtration, and the kinetic data showed
K

m

values of 16.64 mg/ml of culture fluid for carboxymethylcellulase and 0.14 mM
p
-nitrophenyl-β-
d
-glucoside and 0.81 mM cellobiose for β-glucosidase at pH 5. Carboxymethylcellulase and extracellular β-glucosidase functioned optimally at pH 5 to 6 and 4.5 to 5 and at temperatures of 55 to 60 and 70 to 75°C, respectively. Both temperature optima and thermostability of β-glucosidase were among the highest ever reported for the same enzyme excreted from cellulase and β-glucosidase hyperproducing microorganisms.
Physiological Ecology of a Gliding Bacterium Containing Bacteriochlorophyll
a
Authors: Pierson Beverly K. , Giovannoni Stephen J. , Castenholz Richard W.
Published: January 2020

A filamentous, gliding, thermophilic bacterium, found growing abundantly as a surface mat in a limited number of alkaline hot springs in Oregon, is described and designated F-1. The bacteria were studied in the field and in coculture with an aerobic chemoheterotroph. The bacteria are phototrophic and contain bacteriochlorophyll
a
and several carotenoid pigments. Unlike the other gliding phototrophic bacteria, members of the family
Chloroflexaceae
, F-1 does not contain chlorosomes or bacteriochlorophyll
c
or
d
. The light-dependent uptake of simple organic compounds (acetate and glucose) was demonstrated in field populations. Near-infrared radiation sustained this uptake, which occurred equally well under aerobic or anaerobic conditions and was insensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea. The bacteria formed conspicuous dominant mats from about 35 to 56°C, and they covered mats of cyanobacteria in the spring, summer, and autumn months. It appears that they depend on high light intensities to maintain a dense population.
Seasonal occurrence of rotavirus in sewage
Authors: Hejkal T W , Smith E M , Gerba C P
Published: January 2020

A seasonal distribution was observed for rotaviruses in sewage by using indirect immunofluorescence. Levels were low from May through September and generally higher during winter and spring. In contrast, no seasonal pattern was observed for total enteroviruses. Limitations of the indirect immunofluorescence assay and enzyme immunoassay for environmental samples are discussed.