bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification of the mosquitocidal and cytolytic proteins of Bacillus thuringiensis subsp. israelensis
Authors: Hurley J M , Bulla L A , Andrews R E
Published: January 2020

Two proteins from parasporal crystals of Bacillus thuringiensis subsp. israelensis were purified to electrophoretic homogeneity by gel filtration and anion-exchange chromatography. The larger of the two proteins (molecular weight, 68,000) was not cytolytic, whereas the smaller protein (molecular weight, 28,000) was highly cytolytic when assayed against rat erythrocytes. When these proteins were assayed against larvae of the yellow fever mosquito, Aedes aegypti, the larger protein was at least 100-fold more toxic than the smaller protein. Although proteolytic activity was not detected in solubilized crystals nor in purified protein preparations, the toxin (molecular weight, 68,000) was readily degraded to smaller, nontoxic molecules, even when maintained at 4 degrees C. Mixtures of the two purified proteins were significantly more toxic to mosquito larvae than was either protein alone. Thus, it is likely that both the mosquitocidal and the cytolytic protein play roles in the overall insecticidal action of the parasporal crystal produced by this bacterium.
6-Methyl-1,2,4-benzenetriol, a new intermediate in penicillic acid biosynthesis in Penicillium cyclopium
Authors: Sekiguchi J , Katayama S , Yamada Y
Published: January 2020

Penicillic acid-negative mutants were obtained from a color mutant derived from Penicillium cyclopium NRRL 1888 through N-methyl-N'-nitro-N-nitrosoguanidine treatment. One mutant (SK2N6) accumulated 6-methyl-1,2,4-benzenetriol, which was not previously known to be a metabolite of P. cyclopium, in addition to orsellinic acid and orcinol. The radioactivity of [1-14C]acetic acid was rapidly incorporated into 6-methyl-1,2,4-benzenetriol in a culture of P. cyclopium SK2N6. Moreover, the radioactivity of [14C]6-methyl-1,2,4-benzenetriol was efficiently incorporated into penicillic acid in a culture of P. cyclopium NRRL 1888. These data indicate that 6-methyl-1,2,4-benzenetriol is a precursor for penicillic acid biosynthesis. The results on the addition of 1,4-dihydroxy-6-methoxy-2-methylbenzene, 6-methoxy-2-methylbenzoquinone(1,4), and 1-O-methylorcinol to a culture of P. cyclopium SK2N6 indicated that only the former two compounds are converted to penicillic acid. Thus, a new portion of the penicillic acid biosynthetic pathway is proposed.
Interactions of
Lactobacillus bulgaricus
Temperate Bacteriophage 0448 with Host Strains
Authors: Cluzel Pierre-Jean , Serio Jacques , Accolas Jean-Pierre
Published: January 2020

Lactobacillus bulgaricus
LT4(0448) is a lysogenic strain from which a temperate bacteriophage can be induced by mitomycin C or UV irradiation.
Lactobacillus lactis
CNRZ 326 is an indicator strain for the temperate phage 0448, but this strain lyses only in the presence of Ca
2+
ions. A resistant culture developed secondarily after phage lysis and grew normally in MRS broth but again lysed abruptly if Ca
2+
ions were added after two or three transfers. This behavior of the secondary culture and its subcultures is explained by a heterogeneous and fluctuating bacterial population, including clones identical to
L. lactis
326, which were sensitive to 0448 and which formed rough colonies, as does the indicator. The proportion of these clones increased in the course of transfers in MRS, explaining lysis when Ca
2+
was added. The population also included clones which formed smooth colonies (S clones). SI clones, which could not be induced by mitomycin C, were the major type in the initial culture, although they were sensitive to temperate phage 0448. The SI population then decreased and was gradually replaced by SII clones, inducible by mitomycin C and resistant to 0448. These SII clones were lysogenized clones, 326(0448), whose stability was confirmed by growth in the presence of an antiphage serum. When
L. bulgaricus
LT4(0448) was treated with mitomycin C, several cured LT4 clones were obtained that were related to the clones of the indicator
L. lactis
326; they formed rough colonies. They also became sensitive to lytic phages or temperate phages active against
L. lactis
326 and insensitive to lytic phages which lysed
L. bulgaricus
LT4(0448). This suggests that phage 0448 can lead to a lysogenic conversion of host strain LT4.
Ecology of Indigenous Soil Rhizobia: Response of
Bradyrhizobium japonicum
to Readily Available Substrates
Authors: Viteri Silvio E. , Schmidt E. L.
Published: January 2020

Populations of indigenous
Bradyrhizobium japonicum
serocluster 123 and serogroups 110 and 138 were studied after various sugars were added to their soil habitat. Loam soil with approximately 10
4
cells of each group per g of soil were amended every 3 days with 0.1% glucose, sucrose, arabinose, xylose, or galactose. Enumerations of the populations were made every 12 days by immunofluorescence assay. Each
B. japonicum
population in the sugar-treated soils increased by about 1 log during the first 12 days, to a maximum of about 10
6
cells by day 36 or 48, irrespective of the sugar added. Maximum growth rates were similar for each group and occurred during the 12-day incubation period. The most rapid growth was in response to arabinose, with a mean generation time of about 3.0 days. Other mean doubling times were 4.0 days with glucose and galactose treatments, 4.5 days with xylose treatment, and 5.4 days with sucrose amendment. These data provide the first direct evidence that indigenous soil rhizobia can compete successfully with other soil bacteria for readily available substrates in soil in the absence of host legume roots or other rhizospheres. The growth rates in soil of the specific
B. japonicum
populations studied were nearly the same with a given sugar treatment but varied considerably with different sugars. The mean generation times of 3 to 5 days are among the first reported growth rates for heterotrophic bacteria in natural soil.
Isolation of Clostridium botulinum type G from Swiss soil specimens by using sequential steps in an identification scheme
Authors: Sonnabend W F , Sonnabend U P , Krech T
Published: January 2020

After Clostridium botulinum type G organisms and toxin were identified in necropsy specimens in cases of unexplained death in adults and infants (O. Sonnabend, W. Sonnabend, R. Heinzle, T. Sigrist, R Dirnhofer, and U. Krech, J. Infect. Dis. 143:22-27, 1981), extensive research to detect C. botulinum type G in soil samples from Switzerland was done. A total of 41 specimens from virgin soil and from cultivated land were examined for the presence of C. botulinum type G and other toxin types. Because of the lack of the lipase marker in type G, the detection of C. botulinum type G was based on the demonstration of type G organisms in enrichment cultures by a type G-specific enzyme-linked immunosorbent assay to detect both the type G toxin and antigen; enrichment cultures in which type G toxin or antigen was identified by enzyme-linked immunosorbent assay were then tested by a type G-specific gel immunodiffusion agar procedure. This method not only isolated strains of type G but also strains of Clostridium subterminale, a nontoxigenic variant of C. botulinum type G. As a consequence of the observed cross-reactions caused by strains of C. subterminale within this test system, all isolates of type G had to be definitively confirmed by mouse bioassay. The sequential steps of these methods seem to be very useful for detecting C. botulinum type G organisms. C. botulinum type G strains were isolated in five soil samples from different locations in close association with cultivated land.(ABSTRACT TRUNCATED AT 250 WORDS)
Growth of
Thiobacillus ferrooxidans
on Elemental Sulfur
Authors: Espejo Romilio T. , Romero Pedro
Published: January 2020

Growth kinetics of
Thiobacillus ferrooxidans
in batch cultures, containing prills of elementary sulfur as the sole energy source, were studied by measuring the incorporation of radioactive phosphorus in free and adsorbed bacteria. The data obtained indicate an initial exponential growth of the attached bacteria until saturation of the susceptible surface was reached, followed by a linear release of free bacteria due to successive replication of a constant number of adsorbed bacteria. These adsorbed bacteria could continue replication provided the colonized prills were transferred to fresh medium each time the stationary phase was reached. The bacteria released from the prills were unable to multiply, and in the medium employed they lost viability with a half-life of 3.5 days. The spreading of the progeny on the surface was followed by staining the bacteria on the prills with crystal violet; this spreading was not uniform but seemed to proceed through distortions present in the surface. The specific growth rate of
T. ferrooxidans
ATCC 19859 was about 0.5 day
−1
, both before and after saturation of the sulfur surface. The growth of adsorbed and free bacteria in medium containing both ferrous iron and elementary sulfur indicated that
T. ferrooxidans
can simultaneously utilize both energy sources.
Involvement of a plasmid in growth on and dispersion of crude oil by Acinetobacter calcoaceticus RA57
Authors: Rusansky S , Avigad R , Michaeli S , Gutnick D L
Published: January 2020

A crude-oil-degrading Acinetobacter species, Acinetobacter calcoaceticus RA57, was isolated by standard enrichment culture techniques on the basis of its ability to utilize the oily sludge found in the vicinity of a local gas station. Strain RA57 was found to contain four plasmids: pSR1 (5.1 kilobases [kb]), pSR2 (5.4 kb), pSR3 (10.5 kb), and pSR4 (20 kb). Both supercoiled and open circular forms of the first three plasmids were identified by two-dimensional gel electrophoresis. Restriction endonuclease analysis of pSR4 demonstrated that the plasmid contained a circular map. Colonies were isolated at random after growth in the presence of acridine orange and found to fall into two categories: (i) those which had lost the ability to grow on and disperse crude oil in liquid culture and concurrently were cured of pSR4 and (ii) those which retained the ability to both grow on and disperse crude oil and which contained pSR4. Strains from the first class continued to grow on hydrocarbon vapors, indicating that the defect associated with the curing of pSR4 was related to the physical interaction of the cells with the hydrocarbon substrate, rather than to its metabolism. No differences in either adherence to hydrocarbons or production of extracellular emulsifying activity were found between the two classes of mutants. In growth experiments on crude oil in mixed culture with strains which either contained or lacked pSR4, no sparing of the growth defect was observed. The results are consistent with the possibility that pSR4 encodes a factor(s) which is tightly associated with the cell surface.
Loss of N2O reductase activity as an explanation for poor growth of Pseudomonas aeruginosa on N2O
Authors: Snyder S W , Bazylinski D A , Hollocher T C
Published: January 2020

N2O uptake activity of cells and N2O reductase activity of the soluble fraction from denitrifying bacteria were assayed. Pseudomonas aeruginosa strains PAO1 and P1 lost most of their N2O uptake activity and the ability to grow well on N2O within 2 to 5 h after exposure to N2O. Extensive loss of N2O reductase activity accompanied the nearly complete loss of N2O uptake activity under N2O. Paracoccus denitrificans retained much, but not all, of both activities and the ability to grow vigorously on N2O. The pattern with P. aeruginosa strain P2 resembled that for PAO1 and P1 except that loss of the activities proceeded at a slower rate and growth could continue for up to 12 h after exposure to N2O. The inability of a number of P. aeruginosa strains to grow well on N2O is therefore a direct consequence of the nearly complete loss of N2O reductase activity. Turnover-dependent inactivation of N2O reductase and its reactivation under reducing conditions occurred in vitro for the enzyme from P. aeruginosa and Paracoccus denitrificans. These events may be significant in determining the activity level of N2O reductase in denitrifying bacteria during N2O respiration.
Increased Effectiveness of Competitive Rhizobium Strains upon Inoculation of
Cajanus cajan
Authors: Hernandez B. S. , Poth M. , Focht D. D.
Published: January 2020

A field study was conducted in lysimeters containing
15
N-enriched soil to determine the effects of four competitive rhizobium strains upon yield parameters of pigeon peas (
Cajanus cajan
). The greatest differences observed were in seed yields; strain P132 effected the highest seed yield (121 ± 20 g per plant), and the control strain (indigenous rhizobia) effected the lowest yield (43.9 ± 8 g per plant). With the exception of seeds and pods, the dry matter weights were not different. Although there appeared to be no effect by inoculum strains on the fractional content of N derived from biological nitrogen fixation when the total plant biomass was considered, strains P132 and 401 partitioned more of the N derived from fixation into seeds and leaves than did the other strains. Because the seeds comprised the major portion of plant N, more total N and more N derived from biological nitrogen fixation (about half of total N) were found in plants inoculated with P132, whereas the smallest amount was found in the uninoculated controls. P132 was also the best competitor with respect to indigenous rhizobia and acounted for all of the nodules found on the plants in which it was inoculated.
Methanogenesis from Methylated Amines in a Hypersaline Algal Mat
Authors: King Gary M.
Published: January 2020

Methane ebullition and high rates of methane production were observed in sediments of a hypersaline pond (180‰) which contained sulfate in excess of 100 mM. The highest rates of methane production were observed in surface sediments associated with an algal mat dominated by a
Spirulina
sp. The mat contained a methylated amine, glycine betaine (GBT), at levels which accounted for up to 20% of the total mat nitrogen. GBT was apparently the source of trimethylamine (TMA), which was also present in the sediment at relatively high concentrations. Patterns of substrate metabolism by the methanogenic populations in sediment slurries suggested that TMA was a major methane precursor. Neither exogenous hydrogen nor acetate stimulated methanogenesis, while addition of a variety of amines including TMA, trimethylamine oxide, GBT, and choline resulted in substantial increases with yields of >70%. The temperature optimum for methanogenesis in this system was 45 to 55°C, which coincided with the observed sediment temperature. Patterns and rates of methane production in this and other hypersaline algal mats may be determined by a complex interaction between salinity, the use of methylated amines for osmoregulation by algae, and the formation of TMA by fermentation.
Population changes of indigenous murine Candida pintolopesii under various experimental conditions and routes of inoculation
Authors: Artwohl J , McClain A , Cera L
Published: January 2020

Fecal Candida pintolopesii population levels were found to be significantly affected by laparotomy-inoculation-Bollman apparatus restraint, laparotomy-inoculation, and a milk diet. Gastrectomized rats could not support yeast populations; in intact animals, yeast cells failed to colonize the gastrointestinal tract distal to the stomach. Copraphagia contributed little to stomach yeast populations, supporting the notion that stomach yeast growth occurs at fairly rapid rates.
Production of an Extracellular Polysaccharide by
Haloferax mediterranei
Authors: Antón Josefa , Meseguer Inmaculada , Rodríguez-Valera F.
Published: January 2020

The extremely halophilic archaebacterium
Haloferax mediterranei
produces an exocellular polymeric substance that gives the colonies a typical mucous character and is responsible for the appearance of a superficial layer in unshaken liquid medium. This exocellular polymeric substance can be obtained from the supernatant of shaken liquid cultures by cold ethanol precipitation, and yields as high as 3 mg/ml have been detected. The substance was produced under all the conditions tested and with all substrates assayed, although higher yields were obtained with sugars, particularly glucose, as carbon and energy source. The total exocellular polymeric substance produced was proportional to the total biomass. The polymer is a heteropolysaccharide containing mannose as the major component. Glucose, galactose, and another unidentified sugar were also present, as well as amino sugars, uronic acids, and a considerable amount of sulfate, which accounts for the acidic nature of the polymer. The infrared spectrum and specific assays showed the absence of acyl groups. The rheological properties of polymer solutions were studied, showing a pseudoplastic behavior and a high apparent viscosity at relatively low concentrations. Viscosity was remarkably resistant to extremes of pH, temperature, or salinity. These characteristics make this polymer interesting for enhanced oil recovery and other applications for which a very resistant thickening agent is required.
Influence of indigenous microbiota on activities of alkaline phosphatase, phosphodiesterase I, and thymidine kinase in mouse enterocytes
Authors: Whitt D D , Savage D C
Published: January 2020

An indigenous microflora introduced into the gastrointestinal tracts of animals in a population of germfree mice affected in different ways three enzymes in small bowel enterocytes. Cells were obtained by techniques designed for sequentially removing enterocytes from the tip of the villus to the crypts of Lieberkühn. The specific activity of alkaline phosphatase, a component of the enterocyte microvillous membrane, did not differ in cells isolated from germfree mice and from those associated with a microflora, while that of phosphodiesterase I, also a part of the microvillous membrane, was approximately 1.5-fold greater in the suspensions from all levels of the villi in germfree mice than in those from the associated animals. By contrast, the specific activity of thymidine kinase, a cytosol enzyme, in suspensions in which the cells were isolated from the lower portion of the villi and crypts was about one-half as great in cells from germfree mice as in those from the same regions of animals with a microbiota. These results support the hypothesis that activities of certain enzymes involved in metabolism, uptake, and incorporation by enterocytes of components of dietary nuclei acids are influenced by a microflora.
Effect of Nitrogen on Polysaccharide Production in a
Porphyridium
sp
Authors: Arad Shoshana (Malis) , Friedman Orit (Dahan) , Rotem Avi
Published: January 2020

Porphyridium
cultures grown on either nitrate or ammonium as the nitrogen source showed similar patterns of growth and cell wall polysaccharide production. The effect of nitrogen on growth and cell wall polysaccharide production was studied by applying three regimens of supply: batch mode, in which nitrate was supplied at the beginning of the experiment and became depleted at day 6; continual mode, in which nitrate was added daily; and deficient mode, in which the cells were cultured in a nitrate-free medium. Growth was similar in the batch- and continual-mode cultures, whereas it was totally inhibited in the deficient-mode culture. Polysaccharide content (per volume) was highest in the batch-mode culture and lowest in the deficient-mode culture. However, polysaccharide production per cell was similar in the continual- and deficient-mode cultures, the highest value being found in the batch-mode culture. In addition to its effect on polysaccharide content, nitrogen affected the polysaccharide distribution between soluble and bound polysaccharides. In the deficientmode culture, most of the cell wall polysaccharide was dissolved in the medium.
Isolation and Characterization of Coumaphos-Metabolizing Bacteria from Cattle Dip
Authors: Shelton Daniel R. , Somich Cathleen J.
Published: January 2020

Coumaphos, an organophosphate insecticide, is used for tick control in cattle dipping vats along the U.S.-Mexican border. Recently, several vats (problem vats) have experienced a loss of efficacy because of microbial degradation. Three morphologically distinct bacteria (designated B-1, B-2, and B-3) that metabolized coumaphos were isolated from enrichment cultures that were initiated from problem vat dip material. In general, amino acids, pyrimidines, and acetate supported growth; carbohydrates were not utilized. Only B-2 required growth factors. In resting cell experiments, coumaphos was hydrolyzed to diethylthiophosphoric acid and chlorferon by all three isolates. Chlorferon was subsequently metabolized by B-1 and B-2 to α-chloro-β-methyl-2,3,4-trihydroxy-
trans
-cinnamic acid. Only B-1 produced additional metabolites. Experiments with [benzo ring-labeled U-
14
C]coumaphos or chlorferon demonstrated that B-1 was capable of both mineralizing and incorporating into biomass the aromatic portion of the molecule. The majority of label, however, was recovered in the form of soluble products, including α-chloro-β-methyl-2,3,4-trihydroxy-
trans
-cinnamic acid. Although B-1 had the capacity to use chlorferon as a carbon source at low concentrations (100 μg/ml), visible growth at higher concentrations (1,000 μg/ml) was not observed. The addition of 400 μg of chlorferon per ml to B-1 cells in the mid-log phase of growth resulted in complete inhibition of growth, while the addition of 100 to 200 μg of chlorferon per ml resulted in partial inhibition. The growth of B-2 and B-3 was inhibited by 100 μg of chlorferon per ml. These data suggest that, although B-1 and, to a lesser extent, B-2 and B-3 are responsible for the primary degradation of coumaphos, other organisms in the enrichment culture may play a secondary role in coumaphos degradation by removing inhibitory products of coumaphos metabolism.
Long-term survival of hepatitis A virus and poliovirus type 1 in mineral water
Authors: Biziagos E , Passagot J , Crance J M , Deloince R
Published: January 2020

The survival in mineral water of hepatitis A virus (HAV) and poliovirus type 1 was compared, under controlled experimental conditions, at 4 degrees C and room temperature. Viral infectivity titers were determined by cell culture titration, while HAV antigenicity was monitored by radioimmunoassay-endpoint titration. Both viruses persisted longest at 4 degrees C. At this temperature, after 1 year of exposure, the inactivation of either HAV or poliovirus type 1 was not important. At room temperature, poliovirus type 1 was not detected after 300 days, whereas HAV was still infectious. For both temperatures, the computed regression coefficients of best-fit lines for inactivation rates for the two viruses were significantly different. The survival of HAV was also studied at 4 degrees C and room temperature in mineral water with 5- and 50-micrograms/ml protein concentrations (i.e., purity of the virus suspension) for 120 days. As shown by a comparison of the regression coefficients for the inactivation rates, the stability of HAV in mineral water depends on protein concentration and temperature. Radioimmunoassay-endpoint titration results showed inactivation patterns similar to those of cell culture titration, with the most significant reduction in HAV antigenicity at room temperature. At the two temperatures, the infectivity of HAV declined at a faster rate than the antigenicity.
Leucine auxotrophy specifically alters the pattern of trichothecene production in a T-2 toxin-producing strain of Fusarium sporotrichioides
Authors: Beremand M N , Van Middlesworth F , Taylor S , Plattner R D , Weisleder D
Published: January 2020

The biosynthetic pathway for trichothecenes in the filamentous fungus Fusarium sporotrichioides NRRL 3299 has been further characterized. Experiments using the techniques of mutational analysis and the incorporation of radiolabeled precursors indicated that leucine is a direct precursor to the isovalerate moiety present in the trichothecene, T-2 toxin. Analysis of trichothecene production in a UV-induced leucine auxotroph also revealed the existence of a branched biosynthetic pathway which results in the coproduction of T-2 toxin and the T-2 toxin analogs neosolaniol, 8-isobutyryl-neosolaniol, and 8-propionyl-neosolaniol. Leucine limitation imposed by the leucine auxotroph simultaneously led to underproduction of T-2 toxin and overproduction of these T-2 toxin analogs, which are produced in small amounts by the wild-type parent. Furthermore, it was shown that the ratio of T-2 toxin to T-2 toxin analogs produced by the leucine auxotroph can be modulated by the concentration of leucine in the medium. These results suggest that the four trichothecenes mentioned above are derived from a common intermediate and that there is competition for this intermediate among the branched pathways leading to these four cometabolites.
Isolation of a methyl parathion-degrading Pseudomonas sp. that possesses DNA homologous to the opd gene from a Flavobacterium sp
Authors: Chaudhry G R , Ali A N , Wheeler W B
Published: January 2020

Two mixed bacterial cultures isolated by soil enrichment were capable of utilizing methyl parathion (O,O-dimethyl O-p-nitrophenylphosphorothioate) and parathion (O,O-diethyl O-p-nitrophenylphosphorothioate) as a sole source of carbon. Four isolates from these mixed cultures lost their ability to utilize the pesticides independently in transfers subsequent to the initial isolation. One member of the mixed cultures, a Pseudomonas sp., however, hydrolyzed the pesticides to p-nitrophenol but required glucose or another carbon source for growth. The crude cell extracts prepared from this bacterium showed an optimum pH range from 7.5 to 9.5 for the enzymatic hydrolysis. Maximum enzymatic activity occurred between 35 and 40 degrees C. The enzyme activity was not inhibited by heavy metals, EDTA, or NaN3. Another isolate from the mixed cultures, a Flavobacterium sp., used p-nitrophenol for growth and degraded it to nitrite. Nitrite was assimilated into the cells under conditions during which the nitrogen source was excluded from the minimal growth medium. The hybridization data showed that the DNAs from a Pseudomonas sp. and from the mixed culture had homology with the opd (organophosphate degradation) gene from a previously reported parathion-hydrolyzing bacterium, Flavobacterium sp. The use of the opd gene as a probe may accelerate progress toward understanding the complex interactions of soil microorganisms with parathions.
Purification and Chemical Properties of
Acinetobacter calcoaceticus
A2 Biodispersan
Authors: Rosenberg E. , Rubinovitz C. , Legmann R. , Ron E. Z.
Published: January 2020

The extracellular dispersant of
Acinetobacter calcoaceticus
A2, referred to as biodispersan, was concentrated by ammonium sulfate precipitation and deproteinized by hot phenol treatment. The active component was an anionic polysaccharide (PS-A2). The specific activity of PS-A2 was approximately three times greater than that of crude biodispersan. PS-A2 had a sedimentation constant of 1.39 S, a diffusion coefficient of 18.8 × 10
−8
cm
2
s
−1
, and a partial molar volume of 0.65 cm
3
g
−1
, yielding an average molecular weight of 51,400. Titration of the polymer gave two inflection points: pK
1
= 3.1 (1.15 μEq/mg) and pK
2
= 8.0 (0.4 μEq/mg). PS-A2 slowly consumed 1.10 μmol of periodate per mg. The
13
C nuclear magnetic resonance spectrum of PS-A2 indicated four methyl groups, four carbonyl C atoms, and four signals in the anomeric region (95 to 110 ppm), indicative of the presence of four different monosaccharides. Strong acid hydrolysis of PS-A2 yielded four reducing sugars: glucosamine, a 6-methyl aminohexose, galactosamine uronic acid, and an unidentified amino sugar. Ruthenium red binding to PS-A2 was stoichiometric: 1 molecule of dye bound per 2.0 carboxyl groups.
Viruses in sewage waters during and after a poliomyelitis outbreak and subsequent nationwide oral poliovirus vaccination campaign in Finland
Authors: Pöyry T , Stenvik M , Hovi T
Published: January 2020

During an outbreak of paralytic poliomyelitis in Finland in 1984 and 1985 the widespread circulation of the causative wild-type serotype 3 poliovirus in the population was documented by demonstrating the virus in sewage water specimens in 13 different locations in the greater Helsinki district and in 13 other cities or towns all over the country. After the nationwide campaign with oral poliovirus vaccine in 1985, poliovirus serotypes 2 and 3 were readily isolated from sewage waters for up to 2 months, whereas type 1 poliovirus seemed to disappear from the sewage more rapidly. All of these isolates were temperature sensitive and therefore most likely vaccine related. The efficacy of the vaccination campaign in regard to elimination of the epidemic type 3 strain was evaluated by a follow-up study on viruses in sewage waters continued for 12 months through the subsequent expected season of poliomyelitis. Several types of enteroviruses, including five vaccine-related poliovirus strains, were identified in the 72 virus-positive specimens out of 93 studied. No wild-type polioviruses were found, indicating the success of the campaign.
Expression and Secretion of a
Cellulomonas fimi
Exoglucanase in
Saccharomyces cerevisiae
Authors: Curry Claudia , Gilkes Neil , O'Neill Gary , Miller Robert C. , Skipper Nigel
Published: January 2020

We used the yeast
MEL1
gene for secreted α-galactosidase to construct cartridges for the regulated expression of foreign proteins from
Saccharomyces cerevisiae.
The gene for a
Cellulomonas fimi
β-1,4-exoglucanase was inserted into one cartridge to create a fusion of the α-galactosidase signal peptide to the exoglucanase. Yeast transformed with plasmids containing this construction produced active extracellular exoglucanase when grown under conditions appropriate to
MEL1
promoter function. The cells also produced active intracellular enzyme. The secreted exoglucanase was N-glycosylated and was produced continuously during culture growth. It hydrolyzed xylan, carboxymethyl cellulose, 4-methylumbelliferyl-β-
d
-cellobiose, and
p
-nitrophenyl-β-
d
-cellobiose. A comparison of the recombinant
S. cerevisiae
enzyme with the native
C. fimi
enzyme showed the yeast version to have an identical

K
m

and pH optimum but to be more thermostable.
Anaerobic degradation of alkylated benzenes in denitrifying laboratory aquifer columns
Authors: Kuhn E P , Zeyer J , Eicher P , Schwarzenbach R P
Published: January 2020

Toluene and m-xylene were rapidly mineralized in an anaerobic laboratory aquifer column operated under continuous-flow conditions with nitrate as an electron acceptor. The oxidation of toluene and m-xylene was coupled with the reduction of nitrate, and mineralization was confirmed by trapping 14CO2 evolved from 14C-ring-labeled substrates. Substrate degradation also took place when nitrous oxide replaced nitrate as an electron acceptor, but decomposition was inhibited in the presence of molecular oxygen or after the substitution of nitrate by nitrite. The m-xylene-adapted microorganisms in the aquifer column degraded toluene, benzaldehyde, benzoate, m-toluylaldehyde, m-toluate, m-cresol, p-cresol, and p-hydroxybenzoate but were unable to metabolize benzene, naphthalene, methylcyclohexane, and 1,3-dimethylcyclohexane. Isotope-dilution experiments suggested benzoate as an intermediate formed during anaerobic toluene metabolism. The finding that the highly water-soluble nitrous oxide served as electron acceptor for the anaerobic mineralization of some aromatic hydrocarbons may offer attractive options for the in situ restoration of polluted aquifers.
Isolation of fecal coliforms from pristine sites in a tropical rain forest
Authors: Rivera S C , Hazen T C , Toranzos G A
Published: January 2020

Samples collected from water accumulated in leaf axilae of bromeliads (epiphytic flora) in a tropical rain forest were found to harbor fecal coliforms. Random identification of fecal coliform-positive isolates demonstrated the presence of Escherichia coli. This bacterium was also isolated from bromeliad leaf surfaces. These data indicate that E. coli may be part of the phyllosphere microflora and not simply a transient bacterium of this habitat. The isolation of fecal coliforms from these sites was unexpected and raises questions as to the validity of using fecal coliforms as indicators of biological water quality in the tropics.
Effect of the novel ionophore tetronasin (ICI 139603) on ruminal microorganisms
Authors: Newbold C J , Wallace R J , Watt N D , Richardson A J
Published: January 2020

The antimicrobial activity of the novel ionophore tetronasin (formerly ICI 139603) was compared with that of monensin for the growth of ruminal bacteria, protozoa, and an anaerobic fungus. The potency of tetronasin toward most bacteria and the fungus was an order of magnitude or more greater than that of monensin. Lactobacillus casei was 55 times more sensitive to tetronasin than to monensin, indicating a potential role for tetronasin in reversing lactic acidosis. Bacteria with a gram-positive ultrastructure were generally sensitive to the ionophores and unable to adapt to grow in their presence. The exception was the cellulolytic Ruminococcus flavefaciens, which adapted during successive cultivation on media with increasing ionophore concentrations to grow at 100-fold higher concentrations of tetronasin than were initially lethal to the organism. Gram-negative bacteria were more resistant and generally able to adapt to grow in the presence of both ionophores. An in vivo trial with cattle and in vitro growth experiments indicated that the effect of tetronasin on ciliate protozoa was minor. In vitro experiments measuring hydrogen production by Neocallimastix frontalis suggested that this fungus would be unable to survive in ruminants receiving tetronasin.
Differentiation of ruminal bacterial species by enzyme-linked immunosorbent assay using egg yolk antibodies from immunized chicken hens
Authors: Ricke S C , Schaefer D M , Cook M E , Kang K H
Published: January 2020

Cross-reactivity among four species of ruminal bacteria was examined by using egg yolk antibodies from immunized Leghorn laying hens and an enzyme-linked-immunosorbent assay. The effects of the four species on the hens were compared on various days postimmunization. Hens injected with the same bacterial species had similar apparent antibody levels over the entire postimmunization period, but only Bacteroides ruminicola B1(4) and Selenomonas ruminantium D antigens elicited early increases in apparent antibody levels during weeks 2 and 3. Antibody cross-reactivity was greatly reduced by week 2, except for antibodies against Streptococcus bovis JB1.
Anaerobic and aerobic metabolism of diverse aromatic compounds by the photosynthetic bacterium Rhodopseudomonas palustris
Authors: Harwood C S , Gibson J
Published: January 2020

The purple nonsulfur photosynthetic bacterium Rhodopseudomonas palustris used diverse aromatic compounds for growth under anaerobic and aerobic conditions. Many phenolic, dihydroxylated, and methoxylated aromatic acids, as well as aromatic aldehydes and hydroaromatic acids, supported growth of strain CGA001 in both the presence and absence of oxygen. Some compounds were metabolized under only aerobic or under only anaerobic conditions. Two other strains, CGC023 and CGD052, had similar anaerobic substrate utilization patterns, but CGD052 was able to use a slightly larger number of compounds for growth. These results show that R. palustris is far more versatile in terms of aromatic degradation than had been previously demonstrated. A mutant (CGA033) blocked in aerobic aromatic metabolism remained wild type with respect to anaerobic degradative abilities, indicating that separate metabolic pathways mediate aerobic and anaerobic breakdown of diverse aromatics. Another mutant (CGA047) was unable to grow anaerobically on either benzoate or 4-hydroxybenzoate, and these compounds accumulated in growth media when cells were grown on more complex aromatic compounds. This indicates that R. palustris has two major anaerobic routes for aromatic ring fission, one that passes through benzoate and one that passes through 4-hydroxybenzoate.
Sensitivity of pathogenic and free-living Leptospira spp. to UV radiation and mitomycin C
Authors: Stamm L V , Charon N W
Published: January 2020

The habitats for the two major Leptospira spp. differ. The main habitat of L. biflexa is soil and water, whereas L. interrogans primarily resides in the renal tubules of animals. We investigated whether these two species, along with L. illini (species incertae sedis), differ with respect to their sensitivity to UV radiation. The doses of UV resulting in 37, 10, and 1% survival were determined for representative serovars from each species. L. interrogans serovar pomona was 3.0 to 4.8 times more sensitive to UV than the other Leptospira species under the 37, 10, and 1% survival parameters. In comparison to other bacteria, L. interrogans serovar pomona is among the most sensitive to UV. In a qualitative UV sensitivity assay, L. interrogans serovars were found to be in general more sensitive than L. biflexa serovars. All three species were found to have a photoreactivation DNA repair mechanism. Since organisms that are resistant to UV are often resistant to the DNA cross-linking agent mitomycin C, we tested the relative sensitivity of several Leptospira serovars to this compound. With few exceptions, L. biflexa and L. illini serovars were considerably more resistant to mitomycin C than the L. interrogans serovars. The mitomycin C sensitivity assay could be a useful addition to current characterization tests used to differentiate the Leptospira species.
Effect of Plasmid Incompatibility on DNA Transfer to
Streptococcus cremoris
Authors: van der Lelie Daniel , van der Vossen Jos M. B. M. , Venema Gerard
Published: January 2020

Several
Streptococcus cremoris
strains were used in protoplast transformation and interspecific protoplast fusion experiments with
Streptococcus lactis
and
Bacillus subtilis
, with pGKV110, pGKV21, and ΔpAMβ1 as the marker plasmids. ΔpAMβ1 is a 15.9-kilobase nonconjugative, deletion derivative of pAMβ1, which is considerably larger than the pGKV plasmids (approximately 4.5 kilobases). In general, ΔpAMβ1 was transferred more efficiently than the pGKV plasmids. Using electroporation, we were able to demonstrate that failure of efficient transfer for the pGKV plasmids was, except for one case, caused by incompatibility of these plasmids with resident plasmids of the recipient strain.
Inhibitory Effects of Methylcellulose on Cellulose Degradation by
Ruminococcus flavefaciens
Authors: Rasmussen M. A. , Hespell R. B. , White B. A. , Bothast R. J.
Published: January 2020

Highly methylated, long-chain celluloses strongly inhibited cellulose degradation by several species of cellulolytic bacteria of ruminal origin. Specifically, the inhibitory effects of methylcellulose on the growth of
Ruminococcus flavefaciens
FD1 were concentration dependent, with complete inhibition at 0.1% (wt/vol). However, methylcellulose did not inhibit growth on cellobiose or cellulooligosaccharides. Mixtures of methylated cellulooligosaccharides having an average degree of polymerization of 6.7 to 9.5 inhibited cellulose degradation, but those with an average degree of polymerization of 1.0 to 4.5 did not. Similar inhibitory effects by methylcellulose and, to a lesser extent, by methyl cellulooligosaccharides were observed on cellulase activity, as measured by hydrolysis of
p
-nitrophenyl-β-
d
-cellobioside.
R. flavefaciens
cultures hydrolyzed cellulooligosaccharides to cellobiose and cellotriose as final end products. Cellopentaose and cellohexaose were cleaved to these end products, but cellotetraose was also formed from cellohexaose. Methylcellulose did not inhibit hydrolysis of cellulooligosaccharides. These data are consistent with the presence of separate cellulase (β-1,4-glucanase) and cellulodextrinase activities in
R. flavefaciens.
Isolation and Characterization of Xylan-Degrading Strains of
Butyrivibrio fibrisolvens
from a Napier Grass-Fed Anaerobic Digester
Authors: Sewell G. W. , Aldrich H. C. , Williams D. , Mannarelli B. , Wilkie A. , Hespell R. B. , Smith P. H. , Ingram L. O.
Published: January 2020

Six new xylanolytic bacterial strains have been isolated from a Napier grass-fed anaerobic digester. These strains were identified as
Butyrivibrio fibrisolvens
and were similar in many respects to ruminal isolates described previously. The new isolates exhibited a high degree of DNA homology with several ruminal strains of
B. fibrisolvens.
Xylan or xylose was required to induce the production of enzymes for xylan degradation, xylanase and xylosidase. Production of these enzymes was repressed in the presence of glucose. Xylanase activity was predominantly extracellular, while that of xylosidases was cell associated. The new isolates of
B. fibrisolvens
grew well in defined medium containing xylan as the sole carbon source and did not produce obvious slime or capsular layers. These strains may be useful for future genetic investigations.
Biodegradation of crystal violet by the white rot fungus Phanerochaete chrysosporium
Authors: Bumpus J A , Brock B J
Published: January 2020

Biodegradation of crystal violet (N,N,N',N',N'',N''-hexamethylpararosaniline) in ligninolytic (nitrogen-limited) cultures of the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance of crystal violet and by the identification of three metabolites (N,N,N',N',N''-pentamethylpararosaniline, N,N,N',N''-tetramethylpararosaniline, and N,N',N''-trimethylpararosaniline) formed by sequential N-demethylation of the parent compound. Metabolite formation also occurred when crystal violet was incubated with the extracellular fluid obtained from ligninolytic cultures of this fungus, provided that an H2O2-generating system was supplied. This, as well as the fact that a purified ligninase catalyzed N-demethylation of crystal violet, demonstrated that biodegradation of crystal violet by this fungus is dependent, at least in part, upon its lignin-degrading system. In addition to crystal violet, six other triphenylmethane dyes (pararosaniline, cresol red, bromphenol blue, ethyl violet, malachite green, and brilliant green) were shown to be degraded by the lignin-degrading system of this fungus. An unexpected result was the finding that substantial degradation of crystal violet also occurred in nonligninolytic (nitrogen-sufficient) cultures of P. chrysosporium, suggesting that in addition to the lignin-degrading system, another mechanism exists in this fungus which is also able to degrade crystal violet.
Cloning and characterization of the tetracycline resistance determinant of and several promoters from within the conjugative transposon Tn919
Authors: Hill C , Venema G , Daly C , Fitzgerald G F
Published: January 2020

Tn919 is a 15- to 16-kilobase (kb) tetracycline resistance conjugative transposon that was originally isolated from Streptococcus sanguis FC1. The tetracycline resistance determinant (tet) was found on a 4.2-kb HindII fragment by in vitro deletion analysis. This fragment was subcloned to a pWV01 origin capable of directing replication in Escherichia coli, Bacillus subtilis, and Streptococcus lactis, and expression was observed in all three genera. In all cases, expression was weaker when only the 4.2-kb cloned fragment rather than the full transposon was present. The resistance gene is of the streptococcal tetM class and codes for a protein of approximately 70 kilodaltons. The restriction map resembles that of the tetM gene of Tn1545 (P. Martin, P. Trieu-Cuot, and P. Courvalin, Nucleic Acids Res. 14:7047-7058, 1986), which codes for a protein of 72.5 kilodaltons. A number of transposon-derived promoter-bearing fragments were also cloned and sequenced. These closely resemble the consensus sequence of E. coli and B. subtilis promoters. Fusion experiments with a truncated lacZ gene indicate the possibility of an open reading frame for one of the promoters.
Isolation and characterization of an anaerobic dehydrodivanillin-degrading bacterium
Authors: Chen W , Ohmiya K , Shimizu S , Kawakami H
Published: January 2020

A novel, strictly anaerobic, gram-negative, non-spore-forming, fusiform, rod-shaped bacterium having high dehydrodivanillin (DDV)-degrading activity was isolated from cow ruminal fluid. This strain degraded a range of six main lignin-related compounds such as DDV, ferulic acid, dehydrodiisoeugenol, guaiacoxyacetic acid, vanillin, and veratrylglycerol-beta-guaiacyl ether to the extent of 14 to 83% within 2 days under strictly anaerobic conditions. As DDV degradation intermediates, three aromatic compounds (dehydrodivanillic acid, vanillic acid, and 5-carboxyvanillic acid) and two alicyclic compounds (cyclohexanecarboxylic acid and cyclohexanol) were detected by thin-layer, high-performance liquid, and gas chromatography and mass spectrometry. The addition of 1% glucose and peptone in a synthetic medium stimulated growth of the strain but slowed down DDV degradation. The presence of 0.1% yeast extract increased both cell growth and DDV degradation. The growth yield in defined medium was 151.5 g (dry weight) of cells per mol of DDV utilized. Characterization of the strain indicated that it was distinct from known Fusobacterium and Clostridium species. The bacterium was easily induced to form protoplasts after treatment with either penicillin or lysozyme. The frequencies of protoplast formation and regeneration in the strain were 94 and 18%, respectively.
Decreased UV light resistance of spores of Bacillus subtilis strains deficient in pyrimidine dimer repair and small, acid-soluble spore proteins
Authors: Setlow B , Setlow P
Published: January 2020

Loss of small, acid-soluble spore protein alpha reduced spore UV resistance 30- to 50-fold in Bacillus subtilis strains deficient in pyrimidine dimer repair, but gave only a 5- to 8-fold reduction in UV resistance in repair-proficient strains. However, both repair-proficient and -deficient spores lacking this protein had identical heat and gamma-radiation resistance.
Transfer of Plasmids between
Bacillus subtilis
and
Streptococcus lactis
Authors: Baigorí Mario , Sesma Fernando , de Ruiz Holgado Aída P. , de Mendoza Diego
Published: January 2020

The shuttle plasmid pGK12, as well as several
Staphylococcus aureus
plasmids, was introduced into
Streptococcus lactis
by intergeneric protoplast fusion with
Bacillus subtilis.
The
S. aureus
plasmids were stably inherited in
S. lactis,
and so they may possibly be used as cloning vectors in lactic streptococci.
Isolation and Preliminary Characterization of Twenty Bacteriophages Infecting Either
Brevibacterium
or
Arthrobacter
Strains
Authors: Trautwetter Annie , Blanco Carlos
Published: January 2020

Thirty-seven bacteriophages plaquing on
Corynebacterium, Brevibacterium
, or
Arthrobacter
strains were isolated from soil or vegetation samples. Restriction analysis of phage DNA indicated that 20 phages were unique; one of them produced entirely turbid plaques on
Brevibacterium ketoglutamicum
and was characterized as temperate. All these phages were assigned to group B of the classification of Bradley (Bacteriol. Rev. 31:230-314, 1967) and had relatively narrow host ranges.