bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromatofocusing: a new method for purification of staphylococcal enterotoxins B and C1
Authors: Ende I A , Terplan G , Kickhöfen B , Hammer D K
Published: January 2020

A new chromatographic procedure was developed which obtained highly purified preparations of staphylococcal enterotoxins B and C1 in yields of 60% from cultures of Staphylococcus aureus and which is faster than any of the separation methods used previously. The procedure involves chromatography on carboxymethylcellulose, removal of alpha-toxin by adsorption to rabbit erythrocyte membranes, and finally, chromatofocusing as the fundamental new step. Enterotoxins were obtained in highly purified form and behaved in a homogeneous manner as determined by ultracentrifugation and electrophoresis on polyacrylamide gel in the presence of sodium dodecyl sulfate, with molecular weights of 34,000 for staphylococcal enterotoxin B and 30,000 for staphylococcal enterotoxin C1. Using chromatofocusing as the final purification step, we isolated three B and six C1 distinct but immunologically identical enterotoxin fractions, which were found to be devoid of any impurities and to possess a marked degree of toxicity in monkeys.
Utilization of PP
i
as an Energy Source by a
Clostridium
sp
Authors: Cruden Diana L. , Durbin W. E. , Markovetz A. J.
Published: January 2020

The growth of an anaerobic, spore-forming rod we have isolated from the cockroach gut after enrichment on media containing PP
i
was stimulated by the presence of PP
i
. The doubling time decreased and cell yield increased proportionately to PP
i
concentrations of up to 0.35%. A similar stimulation of the growth of
Desulfotomaculum
sp. by PP
i
has been reported. The PP
i
-stimulated
Clostridium
sp. fermented a number of sugars with the production of hydrogen, acetate, and butyrate, with smaller amounts of ethanol and butanol being produced from some substrates. The fermentation products were not qualitatively changed by the presence of PP
i
, but significantly more hydrogen was produced. The organism contained several of the enzymes previously reported from
Entamoeba
sp. and
Propionibacterium
sp., in which PP
i
serves as a source of a high-energy bond in place of ATP. These include significant amounts of pyruvate-phosphate dikinase and phosphoenolpyruvate carboxytransphosphorylase. The activities of many of the catabolic enzymes of the organism, as well as of its phosphatases and pyrophosphatase, were similar whether it was grown in the presence or absence of PP
i
. The organism did not accumulate intracellular polyphosphate granules but stored large amounts of glycogen.
Enterobacteriaceae and Aeromonas hydrophila in Minnesota frogs and tadpoles (Rana pipiens)
Authors: Hird D W , Diesch S L , McKinnell R G , Gorham E , Martin F B , Meadows C A , Gasiorowski M
Published: January 2020

In 222 Rana pipiens frogs and 34 tadpoles captured in and near Minnesota, Aeromonas hydrophila and 29 species of Enterobacteriaceae, including yersinia enterocolitica and Salmonella arizonae, were isolated from intestines. The prevalence of members of the family Enterobacteriaceae was lowest in frogs captured in early spring and highest in frogs captured in late summer.
Proteinases produced by pseudomonads isolated from sheep fleece
Authors: London C J , Griffith I P , Kortt A A
Published: January 2020

Fifty-nine pseudomonads isolated from sheep fleece were able to grow on a minimal salts medium with glycerol as the sole source of carbon and energy. Many of these isolates showed additional growth when collagen-based or wool-based substrates were included in the medium. After several days of incubation with these substrates, the nature of soluble proteins present in the growth medium was investigated by using polyacrylamide gel electrophoresis. Up to four major bands of protein with proteinase activity and with widely different electrophoretic mobilities were detected in the gels; one of the bands appeared as a doublet at times. The electrophoretic mobilities of each class of proteinase were similar for the different pseudomonads examined, but the proteinase (or combination of proteinases) induced depended on the protein substrate and strain or species of pseudomonad used.
Use of nitrifying activity measurements for describing the effect of salinity on nitrification in the Scheldt estuary
Authors: Somville M
Published: January 2020

Nitrifying activity measurements, carried out on freshly collected samples from an estuarine environment, show that the composition of the nitrifier population undergoes a progressive modification during the mixing of freshwater masses in seawater, with increasing tolerance to salt. As a result, the overall effect of increasing salinity on nitrification is much less severe than the direct effect of salt on the freshwater nitrifying population.
Association of Campylobacter jejuni with laying hens and eggs
Authors: Doyle M P
Published: January 2020

Laying hens were individually caged at 20 weeks of age and tested for fecal excretion of Campylobacter jejuni (minimum level of detection was 100 cfu/g) during a 42-week period. Peak rates of C. jejuni isolation (approximately 25% of hens positive) occurred at two different times, in October and in late April to early May. Before being segregated in late September, birds were allowed to consume fecal matter, litter, and communal drinking water, all likely sources of C. jejuni. The increased excretion rate in late April may have been due to a climatic change. A small portion (8.1%) of the hens chronically excreted (positive less than 30% of the sampling times) the organism, whereas C. jejuni was not detected in 33% of the hens, even though birds were likely exposed to the organism before being segregated. No correlation could be made between rates of C. jejuni excretion and egg production. Of 266 eggs from hens fecally excreting C. jejuni, the organism was isolated from two shell surfaces but no egg contents. Egg penetration studies revealed that the organism would not penetrate into the contents of the eggs but could be isolated occasionally from the inner shell and membranes of refrigerated eggs.
Microbial transformation of primaquine by Candida tropicalis
Authors: Clark A M , Hufford C D , Gupta R C , Puri R K , McChesney J D
Published: January 2020

The microbial metabolism of primaquine, a 6-methoxy-8-aminoquinoline antimalarial agent, was investigated. The yeast Candida tropicalis was found to convert primaquine to the previously reported N-acetylated derivative. On continued incubation of C. tropicalis in the presence of the N-acetylated derivative, a minor dimeric metabolite was formed. The proposed structure of the metabolite was based primarily on the analysis of its spectroscopic properties (1H and 13C nuclear magnetic resonance spectra and field-desorption mass spectrum). The structure of the metabolite was proven by direct comparison with an authentic sample of the minor dimeric metabolite prepared by treatment of the N-acetylated derivative with formaldehyde in the presence of formic acid in methanol.
Alginase enzyme production by Bacillus circulans
Authors: Hansen J B , Doubet R S , Ram J
Published: January 2020

Stream and soil samples were screened for microorganisms that would use alginate from mucoid Pseudomonas aeruginosa as the sole carbon and energy source. A pure culture containing large aerobic rods was isolated. The cells were about 0.8 by 2.5 microns in size, had lateral or peritrichous flagella, had a negative Gram stain reaction, and produced spores on sporulation medium. Purified DNA was approximately 46 mol% G+C as measured by thermal denaturation. From these and other biochemical tests, the organism was identified as Bacillus circulans. The enzyme activity that degraded alginate appeared in the culture medium. Upon gel filtration, alginase activity eluted as a single peak at a position corresponding to a protein of 40,000 daltons. Activity recovered from this one-step, partial purification showed apparent endomannuronidase specificity. Like other alginases previously reported, the enzyme appeared likely to be a lyase (or eliminase). However, no Bacillus species or other gram-positive bacteria have heretofore been reported to produce extracellular enzymes with alginase activity. Several other B. circulans strains from the American Type Culture Collection also appeared to have inducible extracellular alginase activity.
Isolation and Characterization of Vacuoles from the Ergot Fungus
Claviceps purpurea
Authors: Keller Ullrich , Madry Norbert , Kleinkauf Horst , Glund Konrad
Published: January 2020

Protoplasts of
Claviceps purpurea
were prepared by treatment of mycelium with a lytic mixture of snail gut enzyme and cellulase from
Trichoderma viride
. Such protoplasts could be efficiently lysed by Triton X-100 treatment at high osmotic pressure without Ca
2+
or Mg
2+
, allowing the release of intact vacuoles in high yields. Vacuoles obtained from cells grown in modified Vogel medium (vegetative-type cells not producing alkaloids) were isolated and purified by centrifugation from a 5% Ficoll 400 (wt/vol) phase into the interphase between two layers, one containing 0.25 M each of mannitol and sucrose, and one containing 0.5 M mannitol. Vacuoles derived from cells grown in a medium favoring ergot alkaloid synthesis (sclerotia-like cells) were isolated by gentle centrifugation of filtered protoplast lysates without addition of Ficoll 400. Biochemical analyses of the vacuole fraction isolated from either kind of cell revealed their function as compartments harboring several hydrolytic enzymes. However, the enrichment of free amino acids in vacuoles of sclerotia-like cells was less pronounced than that in vacuoles of vegetative-type cells, indicating a difference in metabolic compartmentation in the two types of cells.
Degradation of Putrescine and Cadaverine in Seawater Cultures by Marine Bacteria
Authors: Höfle Manfred G.
Published: January 2020

Marine bacteria removed two diamines, putrescine and cadaverine, from coastal seawater supplemented only with these compounds. Batch cultures of natural bacterial communities were grown in filtered seawater (0.05 μm) supplemented with 500 μg of putrescine or cadaverine per liter. Increases in bacterial cell number were counted with an epifluorescence microscope after acridine orange staining. Removal of diamines from seawater was monitored by high-performance liquid chromatography. Diamines were removed from the seawater cultures within 48 h with no corresponding increase in bacterial yield, growth rate, or viability relative to control (unsupplemented) cultures. Shipboard experiments with open-ocean deep water (1,500 m) showed similar, if slower, removal of putrescine from seawater. Unlike uptake experiments with amino acids, labeled putrescine experiments indicated that most putrescine carbon is mineralized to CO
2
rather than assimilated by the bacteria. After growth in unsupplemented control cultures, the bacteria showed a significant potential to mineralize putrescine, indicating a general degradation potential for this compound by marine bacteria even if the compound was not present during growth. Indicators of metabolic activity such as glucose and glutamic acid uptake and mineralization were not affected by the presence of putrescine. This shows that at the concentrations added, the diamines are not toxic, and therefore detoxification was not the reason for degradation of the diamines by the bacteria.
Chloramphenicol acetyltransferase should not provide methanogens with resistance to chloramphenicol
Authors: Beckler G S , Hook L A , Reeve J N
Published: January 2020

Growth of the four methanogens investigated was inhibited by chloramphenicol-3-acetate; therefore, introduction of chloramphenicol acetyltransferase-encoding genes should not confer chloramphenicol resistance on these methanogens. Reduction of the aryl nitro group of chloramphenicol produced a compound which did not inhibit the growth of these methanogens.
Membrane ultrafiltration: concentration of interleukin-3
Authors: Klein F , Ricketts R T , Rohrer T R , Jones W I , Clark P M , Flickinger M C
Published: January 2020

A pilot-plant-scale operation was used for studying membrane ultrafiltration and concentration of kiloliter quantities of the lymphokine interleukin-3 with a single set of membranes. Initial use of ammonium sulfate precipitation of interleukin-3 proved erratic in the recovery of biological activity and resulted in corrosion of the processing equipment. Membrane ultrafiltration proved to be effective in enabling control of the degree of concentration and predicting recovery of the biologically active protein.
Trimethylamine oxide respiration of Alteromonas putrefaciens NCMB 1735: Na+-stimulated anaerobic transport in cells and membrane vesicles
Authors: Stenberg E , Ringø E , Strøm A R
Published: January 2020

Alteromonas putrefaciens NCMB 1735 required the presence of NaCl for anaerobic growth with serine, cysteine, and formate as substrate and trimethylamine oxide ( TMAO ) as external electron acceptor. When lactate was substrate, the organism grew equally well in the absence of NaCl. Anaerobic uptake of glutamate, aspartate, serine, cysteine, and lactate in resting cells was strongly stimulated with NaCl, and cytoplasmic membrane vesicles energized by electron transfer from formate to TMAO displayed active Na+-dependent uptake of serine. The data suggested that participation in transport processes was the only vital function of Na+ in A. putrefaciens. Formate- and TMAO -dependent anaerobic serine uptake in vesicles was sensitive to the protonophore carbonyl cyanide m-chlorophenyl-hydrazone and the ionophores valinomycin and gramicidin. Transport-active vesicles contained cytochromes of b and c type, and both serine uptake and TMAO reduction with formate were inhibited with the electron transfer inhibitor 2-heptyl-4-hydroxyquinoline N-oxide. Thus, reduction of TMAO to trimethylamine in A. putrefaciens appeared to be coupled with a chemiosmotic mechanism of energy conversion.
Denitrification in San Francisco Bay Intertidal Sediments
Authors: Oremland Ronald S. , Umberger Cindy , Culbertson Charles W. , Smith Richard L.
Published: January 2020

The acetylene block technique was employed to study denitrification in intertidal estuarine sediments. Addition of nitrate to sediment slurries stimulated denitrification. During the dry season, sediment-slurry denitrification rates displayed Michaelis-Menten kinetics, and ambient NO
3
−
+ NO
2
−
concentrations (≤26 μM) were below the apparent
K

m

(50 μM) for nitrate. During the rainy season, when ambient NO
3
−
+ NO
2
−
concentrations were higher (37 to 89 μM), an accurate estimate of the
K

m

could not be obtained. Endogenous denitrification activity was confined to the upper 3 cm of the sediment column. However, the addition of nitrate to deeper sediments demonstrated immediate N
2
O production, and potential activity existed at all depths sampled (the deepest was 15 cm). Loss of N
2
O in the presence of C
2
H
2
was sometimes observed during these short-term sediment incubations. Experiments with sediment slurries and washed cell suspensions of a marine pseudomonad confirmed that this N
2
O loss was caused by incomplete blockage of N
2
O reductase by C
2
H
2
at low nitrate concentrations. Areal estimates of denitrification (in the absence of added nitrate) ranged from 0.8 to 1.2 μmol of N
2
m
−2
h
−1
(for undisturbed sediments) to 17 to 280 μmol of N
2
m
−2
h
−1
(for shaken sediment slurries).
Comparative Cytochrome Oxidase and Superoxide Dismutase Analyses on Strains of
Azotobacter vinelandii
and Other Related Free-Living Nitrogen-Fixing Bacteria
Authors: Jurtshuk Peter , Liu Jong-Kang , Moore Edward R. B.
Published: January 2020

Quantitative
N,N,N′,N′
-tetramethyl-
p
-phenylenediamine (TMPD) oxidase and superoxide dismutase (SOD) analyses were performed on representative organisms of the family
Azotobacteraceae. Azotobacter vinelandii, Azotobacter chroococcum, Azotobacter paspali
, and
Derxia gummosa
exhibited high quantitative TMPD oxidase activities, and their extracts possessed very active and electrophoretically homogeneous (single gel band) Fe-type SODs.
Azomonas macrocytogenes
extracts had similar single Fe-type SODs, and their cells exhibited no TMPD-dependent cytochrome oxidase activity. Nitrogen-fixing cells of
Beijerinckia indica, Beijerinckia derxii
, and
Beijerinckia mobilis
exhibited minimal TMPD oxidation capabilities (rates equivalent to the TMPD autooxidation reaction), and these extracts also possessed very active SODs but only of the Mn metallotype.
New methodology for the isolation of Listeria microorganisms from heavily contaminated environments
Authors: Dominguez Rodriguez L , Suárez Fernández G , Fernández Garayzabal J F , Rodriguez Ferri E
Published: January 2020

A new methodology was devised for the isolation of microorganisms of Listeria genus from heavily contaminated materials, by which 88% of tested sheep were identified as carriers. There were 286 strains isolated by our methodology versus 19 by the classical system.
Microbial biodegradation of 4-chlorobiphenyl, a model compound of chlorinated biphenyls
Authors: Massé R , Messier F , Péloquin L , Ayotte C , Sylvestre M
Published: January 2020

The biodegradation products of 4-chlorobiphenyl were analyzed in an Achromobacter sp. strain and a Bacillus brevis strain. Both strains generated the same metabolites, with 4-chlorobenzoic acid as the major metabolic product. Our results corroborate previous observations whereby most bacterial strains degrade the chlorobiphenyls via a major pathway which proceeds by an hydroxylation in position 2,3 and a meta-1,2 fission. However, we also detected several metabolites whose structure suggests the existence of other routes for the degradation of chlorinated biphenyls.
Ghost cells as sorption matrix for virus concentration from water
Authors: Armon R , Kott Y , Neeman I
Published: January 2020

Pig erythrocyte membranes were used as adsorbent material for the concentration of bacteriophage phi x-174, MS-2, and f2 from 5 ml of saline solution. The adsorption was carried out at pH 3.5, and the elution was carried out at pH 7.0. Compared with adsorption on 3% beef extract, bacteriophage adsorption on erythrocyte ghost cells yielded 93 to 100%, and elution was 92 to 100%, whereas beef extract organic flocculation yielded adsorption of 0 to 98.8% and elution of 61 to 86.6%. The same procedure but with poliovirus LSC-1 gave 100% adsorption and 91 to 129% elution.
Detection of streptococcal mutants presumed to be defective in sugar catabolism
Authors: Feary T W , Mayo J A
Published: January 2020

The tetrazolium method for detection of bacterial mutants defective in sugar catabolism was modified for use with streptococci. The critical factors were (i) the concentration of tetrazolium, which must be titrated to determine the optimum concentration for each species or even strain, and (ii) anaerobic incubation of tetrazolium-containing agar plates. When used with standard mutagenesis protocols, this method yielded lactose-negative mutants of nine streptococcal strains representing six species. A collection of lactose-negative mutants of streptococcus, sanguis Challis was characterized and contained phospho-beta-galactosidase, lactose phosphotransferase, and general phosphotransferase mutants.
Effect of noncoliforms on coliform detection in potable groundwater: improved recovery with an anaerobic membrane filter technique
Authors: Franzblau S G , Hinnebusch B J , Kelley L M , Sinclair N A
Published: January 2020

A total of 529 well and distribution potable water samples were analyzed for total coliforms by the most-probable-number and membrane filter (MF) techniques. Standard plate count bacteria and MF noncoliform bacteria were also enumerated. Frequency of coliform detection, turbidity in most-probable-number tubes, and extensive overgrowth by noncoliforms on MF filters were directly proportional to standard plate counts. Recovery of coliforms was greatest by the MF method at low (less than 100 CFU/ml) standard plate count densities and better by the most-probable-number method (confirming gas and turbid tube) at high (greater than 500 CFU/ml) standard plate count densities. In the latter case, overgrowth by noncoliforms on MF filters suppressed sheen development and, in turn, masked coliform detection. Of 341 atypical (no sheen) MF colonies verified by parallel inoculation of lauryl sulfate broth and billiant green-bile broth, 156 were aerogenic in the latter medium. Of atypical isolates, 84% were identified as either Citrobacter or Enterobacter species. A 4.3-fold reduction in numbers of overgrown MF filters and an 2.2-fold increase in numbers of coliforms recovered from 127 water samples was accomplished by anaerobic incubation of MF cultures. This anaerobic modification of the standard MF technique significantly reduced overgrowth and enhanced recovery of coliforms from potable groundwater. This technique is simple, cost effective, and suitable for monitoring of untreated ground water common to some small water systems and private water supplies.
Regulation of aflatoxin biosynthesis: effect of glucose on activities of various glycolytic enzymes
Authors: Buchanan R L , Lewis D F
Published: January 2020

Catabolism of carbohydrates has been implicated in the regulation of aflatoxin synthesis. To characterize this effect further, the activities of various enzymes associated with glucose catabolism were determined in Aspergillus parasiticus organisms that were initially cultured in peptone-mineral salts medium and then transferred to glucose-mineral salts and peptone-mineral salts media. After an initial increase in activity, the levels of glucose 6-phosphate dehydrogenase, mannitol dehydrogenase, and malate dehydrogenase were lowered in the presence of glucose. Phosphofructokinase activity was greater in the peptone-grown mycelium, but fructose diphosphatase was largely unaffected by carbon source. Likewise, carbon source had relatively little effect on the activities of pyruvate kinase, malic enzyme, isocitrate-NADP dehydrogenase, and isocitrate-NAD dehydrogenase. The results suggest that glucose may, in part, regulate aflatoxin synthesis via a carbon catabolite repression of NADPH-generating and tricarboxylic acid cycle enzymes.
Anaerobic incubation of membrane filter cultures for improved detection of fecal coliforms from recreational waters
Authors: Doyle J D , Tunnicliff B , Brickler S K , Kramer R E , Sinclair N A
Published: January 2020

Anaerobic incubation of membrane filter cultures significantly enhanced detection of fecal coliforms in surface-water samples from recreational beaches. In contrast to standard aerobic incubation, anaerobic incubation suppressed overgrowth of masking, noncoliform bacteria but did not increase the frequency of fecal coliform recovery.
Membrane filter staining method: bacterial plate counts in 24 H
Authors: Tse K M , Lewis C M
Published: January 2020

We describe a technique to stain bacterial colonies on membrane filters. The procedure yielded reliable and reproducible bacterial plate counts in 24 h. The procedure can be applied to treated and untreated water samples requiring prompt analysis.
Microbial Specificity of Metallic Surfaces Exposed to Ambient Seawater
Authors: Zaidi B. R. , Bard R. F. , Tosteson T. R.
Published: January 2020

High-molecular-weight materials associated with the extracellular matrix and film found on titanium and aluminum surfaces after exposure to flowing coastal seawater were isolated. This material was purified by hydroxylapatite chromatography and subsequently employed to produce antibodies in the toad,
Bufo marinus
. The antibodies were immobilized on a solid support and employed to isolate adhesion-enhancing, high-molecular-weight materials from the laboratory culture media of bacterial strains recovered from the respective metallic surfaces during the course of their exposure to seawater. The adhesion-enhancing materials produced by the surface-associated bacterial strains were immunologically related to the extracellular biofouling matrix material found on the surfaces from which these bacteria were isolated. The surface selectivity of these bacterial strains appeared to be based on the specificity of the interaction between adhesion-enhancing macromolecules produced by these bacteria and the surfaces in question.
Round robin investigation of methods for recovering human enteric viruses from sludge
Authors: Goyal S M , Schaub S A , Wellings F M , Berman D , Glass J S , Hurst C J , Brashear D A , Sorber C A , Moore B E , Bitton G
Published: January 2020

To select a tentative standard method for detection of viruses in sludge the American Society for Testing and Materials D19:24:04:04 Subcommittee Task Group initiated round robin comparative testing of two procedures that, after initial screening of several methodologies, were found to meet the basic criteria considered essential by the task group. Eight task group member laboratories agreed to perform round robin testing of the two candidate methods, namely, The Environmental Protection Agency or low pH-AlCl3 method and the Glass or sonication-extraction method. Five different types of sludge were tested. For each particular type of sludge, a single laboratory was designated to collect the sludge in a single sampling, make samples, and ship it to the participating laboratories. In most cases, participating laboratories completed all the tests within 48 h of sample arrival. To establish the reproducibility of the methods, each laboratory tested each sludge sample in triplicate for the two candidate virus methods. Each processed sludge sample was quantitatively assayed for viruses by the procedures of each individual round robin laboratory. To attain a more uniform standard of comparison, a sample of each processed sample from all laboratories was reassayed with one cell line and passage number by a single laboratory (Environmental Protection Agency Environmental Monitoring and Support Laboratory, Cincinnati, Ohio). When the data were statistically analyzed, the Environmental Protection Agency method was found to yield slightly higher virus recoveries for all sludge types, except the dewatered sludge. The precisions of both methods were not significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)
Survival of parasite eggs upon storage in sludge
Authors: O'Donnell C J , Meyer K B , Jones J V , Benton T , Kaneshiro E S , Nichols J S , Schaefer F W
Published: January 2020

Destruction rates of parasite eggs in stored sludge were examined to help understand the fate of these agents of enteric diseases in sludge lagoons. Eggs from the roundworms, Ascaris spp., Toxocara spp., Trichuris spp., and the tapeworm, Hymenolepis spp., were treated with domestic sludges by aerobic or anaerobic processes. Sludge samples seeded with eggs were stored at 4 or 25 degrees C or in a container inserted into the ground to simulate lagoon conditions. The number of eggs recovered from the samples decreased with storage time. The viability and infectivity of eggs recovered were related to the storage temperature; i.e., the eggs stored at 4 degrees C remained viable longer than those stored at 25 degrees C. After 25 months at 4 degrees C, the Toxocara eggs and some Ascaris eggs remained both viable and infective, whereas most of these eggs stored at 25 degrees C were rendered nonviable after 10 to 16 months of storage in sludge. Although storage temperature was found to be the most important factor affecting the destruction and viability of these eggs, other factors, such as the type of sludge digestion, whether or not the eggs were digested along with the sludge or added later, storage in the soil versus sludge, pH, and egg species also exhibited some minor effects. These controlled laboratory studies suggest that lagooning of sludge can be an effective method for the elimination of parasite eggs, particularly in warmer geographical locations.
Effect of Monensin on Growth and Methanogenesis of
Methanobacterium formicicum
Authors: Dellinger Carole A. , Ferry James G.
Published: January 2020

Monensin inhibited methanogenesis from formate but not from H
2
-CO
2
by resting-cell suspensions of
Methanobacterium formicicum
. The antibiotic severely inhibited growth on formate. The lag phase of H
2
-CO
2
-grown cultures was prolonged by monensin, but these cultures recovered from the initial inhibition. The recovery did not result from the development of a monensin-resistant population or inactivation of the antibiotic.
Production and characterization of antibody against deoxyverrucarol
Authors: Chu F S , Zhang G S , Williams M D , Jarvis B B
Published: January 2020

Immunization of rabbits with deoxyverrucarol (DOVE) conjugated to bovine serum albumin resulted in antibodies bound with either tritiated DOVE or diacetoxyscirpenol (DAS), but not with T-2 toxin. The affinity of antibodies with DOVE was found to be much higher than with DAS. When [3H] DOVE was used as a marking ligand in the competitive radioimmunoassay, the concentrations causing 50% inhibition of binding radioactivities by unlabeled DOVE, verrucarol, verrucarin A, and 4-monoacetoxyscirpenol were found to be 0.32, 1,070, 9,500, and 10,000 ng per assay, respectively. T-2 toxin, 15-monoacetoxyscirpenol, and deoxynivalenol gave less than 20% inhibition at 10 micrograms per assay. However, when [3H] DAS was used as the marking ligand, the concentrations causing 50% inhibition by DOVE, DAS, and verrucarol were found to be in the 50 to 60 ng per assay range. The antibodies are thus highly specific to DOVE rather than a common trichothecene backbone. The possible use of this antiserum for assay of macrocyclic trichothecenes is discussed.
Identification of Heterotrophic Nitrification in a Sierran Forest Soil
Authors: Schimel Joshua P. , Firestone Mary K. , Killham Kenneth S.
Published: January 2020

A potential for heterotrophic nitrification was identified in soil from a mature conifer forest and from a clear-cut site. Potential rates of NO
2
−
production were determined separately from those of NO
3
−
by using acetylene to block autotrophic NH
4
+
oxidation and chlorate to block NO
2
−
oxidation to NO
3
−
in soil slurries. Rates of NO
2
−
production were similar in soil from the forest and the clear-cut site and were strongly inhibited by acetylene. The rate of NO
3
−
production was much greater than that of NO
2
−
production, and NO
3
−
production was not significantly affected by acetylene or chlorate. Nitrate production was partially inhibited by cycloheximide, but was not significantly reduced by streptomycin. Neither the addition of ammonium nor the addition of peptone stimulated NO
3
−
production.
15
N labeling of the NH
4
+
pool demonstrated that NO
3
−
was not coming from NH
4
+
. The potential for heterotrophic nitrification in these forest soils was greater than that for autotrophic nitrification.
Production of
d
-Tagatose from Dulcitol by
Arthrobacter globiformis
Authors: Izumori Ken , Miyoshi Tatsuji , Tokuda Sachiko , Yamabe Keizo
Published: January 2020

A process for the bacterial oxidation of dulcitol to
d
-tagatose has been developed. The strain
Arthrobacter globiformis
ST48 used in this fermentation was isolated from soil. The yield of
d
-tagatose accumulated in the medium from dulcitol was as high as 85%. About 14 g of
d
-tagatose crystals was isolated from 1 liter of 2% dulcitol medium.
Selection of an Asporogenous Strain of
Clostridium acetobutylicum
in Continuous Culture Under Phosphate Limitation
Authors: Meinecke Beatrix , Bahl Hubert , Gottschalk Gerhard
Published: January 2020

Based on the observation that cells of
Clostridium acetobutylicum
unable to store granulose do not initiate sporulation, a staining procedure was developed for the detection of asporogenous mutants. By application of this procedure it was shown that an asporogenous strain of
C. acetobutylicum
was selected in continuous culture under phosphate limitation.
Multiplicity of aspartate transport in thin wastewater biofilms
Authors: Eighmy T T , Bishop P L
Published: January 2020

This research documents the multiplicity of L-aspartate transport in thin wastewater biofilms. A Line-weaver-Burk analysis of incorporation produced a curvilinear plot (concave down) that suggested active transport by two distinct systems (1 and 2). The inactivation of system 2 with AsO4 or osmotic shock resolved system 1, which was a high-affinity, low-capacity system with an apparent Kt (Michaelis-Menten constant) of 4.3 microM (AsO4) or 4.6 microM (osmotic shock). The inactivation of system 1 with dinitrophenol resolved system 2, which was a low-affinity, high-capacity system with an apparent Kt of 116.7 microM. System 1 was more specific for aspartate than system 2 in the presence of aspartate analogs. Sodium had no discernible effect on the incorporation velocities by either system. These results indicate that system 1 is a membrane-bound proton symport coupled to the proton gradient component of the proton motive force and that system 2 is a binding protein-mediated system coupled to phosphate bond energy. Analyses of diffusional limitations on the derived transport constants indicated that internal resistances were present but that the apparent constants were close to the intrinsic values, especially for system 1. Metabolic inactivation of the biofilm with dinitrophenol and AsO4 did not completely inactivate aspartate incorporation, which indicated that some simple adsorption of the aspartate anion by the biofilm had occurred. These results show that aspartate is transported by wastewater biofilm bacteria via systems with different affinities, specificities, and mechanisms of energy coupling.
Root Hair Deformation, Bacterial Attachment, and Plant Growth in Wheat-
Azospirillum
Associations
Authors: Jain Devender K. , Patriquin David G.
Published: January 2020

Seven
Azospirillum
strains induced more deformation of root hairs of wheat than did strains of
Rhizobium leguminosarum, Azotobacter chroococcum
, or
Escherichia coli. Azospirillum
sp. strain Sp245 caused the most deformation. Strain Sp245 (isolated from surface sterile roots of wheat) and strain Sp7 (isolated from the rhizosphere of a forage grass) were compared with regard to their effects on root hair deformation, their attachment to roots, and their effects on the growth of four wheat cultivars. The amount of deformation caused by the two strains in the four cultivars increased in the following order: cv. Tobari, cv. Tonari, cv. BH1146, cv. Lagoa. Strain Sp245 attached to the roots of all cultivars in low numbers, and attachment did not increase with time (up to 48 h). Strain Sp7 attached in higher numbers, and attachment increased with time. Inoculation of the four cultivars of wheat had pronounced effects on root mass measured at maturity. The magnitude of the effects in the four cultivars increased in the following order: Tobari, Tonari, BH1146, Lagoa; these effects were progressively more positive for strain Sp245 and progressively more negative for strain Sp7. Concentrations of N in wheat did not vary substantially between cultivars or strains. Concentrations of K and P did not vary substantially between cultivars but did vary between strains, Sp245 effecting increases and Sp7 effecting decreases.
Substrate Degradation and Pressure Tolerance of Free-Living and Attached Bacterial Populations in the Intestines of Shallow-Water Fish
Authors: Cleland David R. , McDougald S. Diane , Oliver James D.
Published: January 2020

Bacterial populations attached to intestinal linings of shallow-water fish were compared to those free in the lumen for response to hydrostatic pressure and ability to degrade a variety of substrates. Results suggested that, unlike reports on gut-associated deep-sea bacteria, the two shallow-water populations were not significantly different in their pressure or substrate responsiveness.
Survival and detection of Bacteroides spp., prospective indicator bacteria
Authors: Fiksdal L , Maki J S , LaCroix S J , Staley J T
Published: January 2020

Preliminary experiments were performed to assess the use of intestinal Bacteroides spp. as indicators of fecal contamination of water. Viable counts of Bacteroides fragilis, an anaerobic bacterium, declined more rapidly than those of Escherichia coli and Streptococcus faecalis. However, a fluorescent antiserum prepared against B. fragilis successfully detected high proportions (18 to greater than 50%) of B. fragilis cells suspended for 8 days in aerobic water in dialysis bags at the ambient temperature. These percentages were higher than the percent viable recoveries of the two indicator bacteria used for comparison. Thus, the fluorescent antiserum test for B. fragilis might serve as a useful indicator of fecal contamination of water. An advantage of this approach over coliform analysis is the rapidity at which the test can be performed.
Inoculant Maturity Influences Survival of Rhizobia on Seed
Authors: Materon L. A. , Weaver R. W.
Published: January 2020

Survival of
Rhizobium trifolii
on seeds of arrowleaf clover (
Trifolium versiculosum
Savi) and subclover (
Trifolium subterraneum
L.) was affected by the maturity of peat-, vermiculite-, and charcoal-based inoculants. Ten times more rhizobia survived on seed 4 days after inoculation when inoculants were stored (cured) before being utilized as compared with uncured inoculants. Increasing the curing time of inoculants beyond 4 weeks had little effect on increasing survival of seed-applied rhizobia.
Construction of Tn
3
-Containing Plasmids from Plant-Pathogenic Pseudomonads and an Examination of Their Biological Properties
Authors: Obukowicz Mark , Shaw Paul D.
Published: January 2020

Indigenous plasmids isolated from
Pseudomonas tabaci
ATCC 11528(pJP1),
Pseudomonas angulata
45(pJP30), and
P. tabaci
BR2(pBPW1) (M. Obukowicz and P. D. Shaw, J. Bacteriol. 155:438-442, 1983) were labeled with Tn
3
, and the strains were subsequently cured of their respective plasmids. Plasmid-containing and cured isolates caused plant symptoms that were nearly indistinguishable, and the same amount of tabtoxin was produced by
P. tabaci
strains ATCC 11528 and BR2.
Bacterial and fungal cometabolism of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT) and its breakdown products
Authors: Subba-Rao R V , Alexander M
Published: January 2020

Resting cells of bacteria grown in the presence of diphenylmethane oxidized substituted analogs such as 4-hydroxydiphenylmethane, bis(4-hydroxyphenyl)methane, bis(4-chlorophenyl)methane (DDM), benzhydrol, and 4,4'-dichlorobenzhydrol. Resting cells of bacteria grown with benzhydrol as the sole carbon source oxidized substituted benzhydrols such as 4-chlorobenzhydrol, 4,4'-dichlorobenzhydrol, and other metabolites of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), such as DDM and bis(4-chlorophenyl)acetic acid. Bacteria and fungi converted 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane to 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane, DDM, 4,4'-dichlorobenzhydrol, and 4,4'-dichlorobenzophenone. Aspergillus conicus converted 55% of bis(4-chlorophenyl)acetic acid to unidentified or unextractable water-soluble products. Aspergillus niger and Penicillium brefeldianum converted 12.4 and 24.6%, respectively, of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane to water-soluble and unidentified products. 4-Chlorophenylacetic acid, a product of ring cleavage, was formed from DDM by a false smut fungus of rice. A. niger converted 4,4'-dichlorobenzophenone to 4-chlorobenzophenone and a methylated 4-chlorobenzophenone.
Survey of antimicrobial resistance in lactic streptococci
Authors: Orberg P K , Sandine W E
Published: January 2020

A total of 26 strains of Streptococcus cremoris and 12 strains of Streptococcus lactis were challenged with 18 antimicrobial agents and with nisin in the Bauer-Kirby disk susceptibility test. All strains were susceptible to ampicillin, bacitracin, cephalothin, chloramphenicol, chlortetracycline, erythromycin, penicillin G, tetracycline, and vancomycin. All strains were resistant to trimethoprim, and almost all strains were resistant to sulfathiazole. Variability in resistance to gentamicin, kanamycin, lincomycin, nafcillin, neomycin, nisin, rifampin, and streptomycin was observed. MICs of these substances for the less susceptible strains were determined, and high-level resistance factors could not be detected, except in the case of nisin. S. lactis ATCC 7962 was resistant to at least 40-fold-higher concentrations of nisin (greater than 64 micrograms/ml) than most other strains tested. This strain was a potent nisin producer.
Selective medium for the isolation and enumeration of Klebsiella spp
Authors: Wong S H , Cullimore D R , Bruce D L
Published: January 2020

A highly selective medium for the enumeration and isolation of Klebsiella pneumoniae and Klebsiella oxytoca was developed in which the typical colonies were convex and 1 to 2 mm in diameter. Their pigment was either a mucoid pink-red color or a more watery pale red with a dark red center. Relatively little colonial growth occurred for any other bacterial genera, and where such colonies did grow, they could be easily differentiated since the form was atypical. The medium already appears to have potential value as a means of assessing the efficiency of treating sewage and monitoring the microbiological quality of vegetables.
Lactate metabolism by pediococci isolated from cheese
Authors: Thomas T D , McKay L L , Morris H A
Published: January 2020

Pediococcus pentosaceus is commonly found among the adventitious microflora of Cheddar cheese. When this organism was incubated with L-(+)-lactate under anaerobic conditions, L-(+)-lactate was rapidly converted to D-(-)-lactate until racemic (DL) lactate was present. Under aerobic conditions this initial reaction was followed by a slower reaction resulting in the use of both lactate isomers and in the production of acetate and CO2. With intact cells the lactate oxidation system had an optimum pH of 5 to 6, depending on the initial lactate concentration. Cells grown anaerobically possessed lactate-oxidizing activity which increased two- to fourfold as sugar was exhausted from the medium. Aerobic growth further increased specific activities. Cheddar cheese was made with the deliberate addition of P. pentosaceus. When the resulting cheese was grated to expose a large surface area to O2, lactate was converted to acetate at a rate which depended on the density of pediococci in the cheese. The lactate oxidation system remained active in cheese which had been ripened for 6 months.
Relative resistance to chlorine of poliovirus and coxsackievirus isolates from environmental sources and drinking water
Authors: Payment P , Tremblay M , Trudel M
Published: January 2020

Several poliovirus and coxsackievirus isolates from environmental sources were compared with laboratory strains to determine their rate of inactivation by chlorine. All viruses were tested for up to 1,000 min in the presence of an initial free residual chlorine level of ca. 0.4 mg/liter. Coxsackievirus B5 (CB-5) isolates were found to be more resistant to chlorine than coxsackievirus B4 (CB-4), followed by poliovirus 1, 2, and 3 in order of decreasing resistance to chlorine. Environmental isolates of CB-5 were more resistant than the laboratory strain tested, and for two strains 12 and 22% of the input virus was still infectious after 100 min in the presence of free residual chlorine. Although CB-4 isolates were less resistant to chlorine than CB-5 isolates, after 1,000 min of contact 0.01% of the input virus was still infectious. Except for CB-5 isolates, isolates from environmental sources did not appear to be more resistant to chlorine than laboratory strains. Viruses isolated at different phases during the preparation of drinking water were not more resistant to chlorine and must thus have been protected by other mechanisms.
Influence of Environmental Factors on Interstrain Competition in
Rhizobium japonicum
Authors: Kosslak Renee M. , Bohlool B. Ben
Published: January 2020

The effect of several biotic and abiotic factors on the pattern of competition between two strains of
Rhizobium japonicum
was examined. In two Minnesota soils, Waseca and Waukegan, strain USDA 123 occupied 69% (Waseca) and 24% (Waukegan) of the root nodules on
Glycine max
L. Merrill cv. Chippewa. USDA 110 occupied 2% of the root nodules in the Waseca soil and 12% of the nodules in the Waukegan soil. Under a variety of other growth conditions—vermiculite, vermiculite amended with Waseca soil, and two Hawaiian soils devoid of naturalized
Rhizobium japonicum
strains—USDA 110 was more competitive than USDA 123. The addition of nitrate to or the presence of antibiotic-producing actinomycetes in the rhizosphere of soybeans did not affect the pattern of competition between the two strains. However, preexposure of young seedings to USDA 110 or USDA 123 before transplantation into soil altered the pattern of competition between the two strains significantly. In the Waseca soil, preexposure of cv. Chippewa to USDA 110 for 72 h increased the percentage of nodules occupied by USDA 110 from 2 to 55%. Similarly, in the Hawaiian soil Waimea, nodule occupancy by USDA 123 increased from 7 to 33% after a 72-h preexposure.
Mechanism of biodegradation of paraquat by Lipomyces starkeyi
Authors: Carr R J , Bilton R F , Atkinson T
Published: January 2020

The biodegradation of ring-14C- and methyl-14C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
Factors stimulating migration of holotrich protozoa into the rumen
Authors: Murphy M R , Drone P E , Woodford S T
Published: January 2020

The effects of feeding and various reticular infusions on ruminal holotrich concentrations were studied in an attempt to identify possible factors stimulating their migration into the rumen. It was concluded that glucose entering the reticulo-rumen shortly after feeding could stimulate migration of holotrich protozoa.
Interactions between heterotrophic plate count bacteria and coliform organisms
Authors: LeChevallier M W , McFeters G A
Published: January 2020

Studies were initiated to investigate the interactions between heterotrophic plate count bacteria and coliform organisms. We used spiked samples to show that heterotrophic plate count bacteria could reduce coliform densities by more than 3 logs within 8 days. Some heterotrophic plate count bacteria were able to cause injury to the coliform population. A significant correlation (r = 0.66; P less than 0.05) was observed between the initial level of heterotrophic plate count bacteria and the rate of coliform decline. Competition for limiting organic carbon was hypothesized to be responsible for the observed effects.
Biological Delignification of Aspen Wood by Solid-State Fermentation with the White-Rot Fungus
Merulius tremellosus
Authors: Reid Ian D.
Published: January 2020

Solid-state fermentation of aspen (
Populus tremuloides
) wood with
Merulius tremellosus
for 8 weeks removed 52% of the lignin but only 12% of the total wood weight, and increased the cellulase digestibility to 53% from 18%. Water-soluble and enzyme-solubilized lignin degradation products accumulated. Delignification was fastest at temperatures between 25 and 32.5°C and at a water-to-wood ratio of 2. Initial pH values between 4 and 6 were optimal;
M. tremellosus
acidified the wood to below pH 3.5 as it grew. The fungus tolerated CO
2
concentrations of at least 14% and O
2
concentrations down to 7% in the bulk gas phase. Both simple and complex nitrogen supplements inhibited delignification. Supplementary KH
2
PO
4
, MgSO
4
, CaCl
2
, thiamine, and trace elements had little effect on the fermentation. Four isolates of
M. tremellosus
had very similar abilities to delignify aspen wood. Biological delignification with
M. tremellosus
may be a useful pretreatment for enzymatic saccharification or ruminant feeding.