bluuebunny/crossref_metadata_2025 huggingface dataset:
Methanogenesis from acetate: enrichment studies
Authors: Baresi L , Mah R A , Ward D M , Kaplan I R
Published: January 2020

An acetate enrichment culture was initiated by inoculating anaerobic sludge from a mesophilic methane digestor into a mineral salts medium with calcium acetate as the sole carbon and energy source. This enrichment was maintained indefinitely by weekly transfer into medium of the same composition. A study of this enrichment disclosed an unexpected age-dependent inhibition of methanogenesis by H2 and formate which apparently differed from the inhibition by chloroform and benzyl viologen. This age-dependent inhibition indicated that microbial interactions of the mixed enrichment population may play a regulatory role in methane formation. Futhermore, stimulation of methanogenesis in the acetate enrichment by addition of yeast extract showed a nutrient limitation which indicated that syntrophic interactions leading to formation of growth factors may also occur. A model is presented to illustrate the possible interrelationships between methanogenic and nonmethanogenic bacteria in their growth and formation of methane and carbon dioxide from acetate.
System for evaluating clostridial inhibition in cured meat products
Authors: Robach M C , Ivey F J , Hickey C S
Published: January 2020

A method for evaluating inhibition of Clostridium botulinum, C. sporogenes, and C. perfringens in cured meat products was developed. This system can easily be used in the microbiology laboratory using aluminum ointment tubes as the product container. Swells caused by gas production by the organism are easily observed by using the aluminum tubes. Results obtained confirmed earlier work on the inhibitory effect of sodium nitrite and sorbic acid against the clostridia in cured meat products.
Microbial and chemical transformations of some 12,13-epoxytrichothec-9,10-enes
Authors: Claridge C A , Schmitz H
Published: January 2020

Resting cells of Streptomyces griseus, Mucor mucedo, and a growing culture of Acinetobacter calcoaceticus when mixed with compounds related to 12,13-epoxytrichothec-9-ene-4beta,15-diacetoxy-3alpha-ol(anguidine) produced a series of derivatives that were either partially hydrolyzed or selectively acylated. These derivatives showed marked differences in activities as assayed by antifungal and tissue culture cytotoxicity tests.
Automated food microbiology: potential for the hydrophobic grid-membrane filter
Authors: Sharpe A N , Diotte M P , Dudas I , Michaud G L
Published: January 2020

Bacterial counts obtained on hydrophobic grid-membrane filters were comparable to conventional plate counts for Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus in homogenates from a range of foods. The wide numerical operating range of the hydrophobic grid-membrane filters allowed sequential diluting to be reduced or even eliminated, making them attractive as components in automated systems of analysis. Food debris could be rinsed completely from the unincubated hydrophobic grid-membrane filter surface without affecting the subsequent count, thus eliminating the possibility of counting food particles, a common source of error in electronic counting systems.
Development of quantitative methods for the detection of enteroviruses in sewage sludges during activation and following land disposal
Authors: Hurst C J , Farrah S R , Gerba C P , Melnick J L
Published: January 2020

The development and evaluation of methods for the quantitative recovery of enteroviruses from sewage sludge are reported. Activated sewage sludge solids were collected by centrifugation, and elution of the solid-associated virus was accomplished by mechanical agitation in glycine buffer at pH 11.0. Eluted viruses were concentrated either onto an aluminum hydroxide floc or by association with a floc which formed de novo upon adjustment of the glycine eluate to pH 3.5. Viruses which remained in the liquid phase after lowering the pH of glycine eluate were concentrated by adsorption to and elution from membrane filters. The method of choice included high pH glycine elution and subsequent low pH concentration; it yielded an efficiency of recovery from activated sludge of 80% for poliovirus type 1, 68% for echovirus type 7, and 75% for coxsackievirus B3. This method was used to study the survival of naturally occurring virus in sludge at a sewage treatment plant and after subsequent land disposal of the solids after aerobic digestion. Reduction of enterovirus titers per gram (dry weight) of solids were modest during sludge activation but increased to a rate of 2 log 10/week after land disposal.
Hydrogen peroxide and superoxide radical formation in anaerobic broth media exposed to atmospheric oxygen
Authors: Carlsson J , Nyberg G , Wrethén J
Published: January 2020

Fourteen different broth media were autoclaved under anaerobic conditions and then exposed to atmospheric oxygen. The hydrogen peroxide and superoxide radical formation as well as the bactericidal effect of the media were studied. The rate of killing of Peptostreptococcus anaerobius VPI 4330-1 was high in media that rapidly autoxidized and accumulated hydrogen peroxide. In actinomyces broth (BBL), 50% of the cells were killed within 2 min, and in Brewer thioglycolate medium (Difco), 50% were killed within 11 min, whereas more than 50% of the cells survived for more than 2 h in Clausen medium (Oxoid), fluid thioglycolate medium (BBL), and thioglycolate medium without dextrose or indicator (Difco). Only media that contained phosphate and glucose had a tendency to accumulate hydrogen peroxide. A solution of phosphate and glucose autoxidized when it had been heated to 120 degrees C for at least 5 min and when the pH of the solution was higher than 6.5. Transitional metal ions catalyzed the autoxidation, but they were not necessary for the reaction to occur. Of the other substances heated in phosphate buffer, only alpha-hydroxycarbonyl compounds autoxidized with accumulation of hydrogen peroxide. Superoxide dismutase decreased the autoxidation rate of most of the broth media. This indicated that superoxide radicals were generated in these media.
Inhibition of aflatoxin biosynthesis by tolnaftate
Authors: Khan S N , Maggon K K , Venkitasubramanian T A
Published: January 2020

Tolnaftate [2-napthyl-N-methyl-N-(m-tolyl)thionocarbamate], an antifungal drug, is widely used to control superficial fungal infections in humans and other animals. In this study the effect of tolnaftate on aflatoxin biosynthesis by Aspergillus parasiticus NRRL 3240 was investigated. Tolnaftate changed the morphology of A. parasiticus to yeastlike forms and inhibited aflatoxin formation. The formation of aflatoxin G was blocked considerably, indicating a metabolic block in the conversion of aflatoxin B to aflatoxin G. The incorporation of [1-14C]acetate into aflatoxin was significantly inhibited at a concentration of 1 mM tolnaftate. The presence of zinc in the resuspension buffer resulted in reversal of the tolnaftate-induced inhibition of aflatoxin G1 biosynthesis.
Growth of
Chaetomium cellulolyticum
on Alkali-Pretreated Hardwood Sawdust Solids and Pretreatment Liquor
Authors: Pamment N. , Moo-Young M. , Hsieh F.-H. , Robinson C. W.
Published: January 2020

The treatment of a hardwood sawdust with 1% NaOH solution at 121°C dissolved 19.7% of the dry matter, mainly hemicellulose and lignin. Fermentation of the treated solids by
Chaetomium cellulolyticum
for 48 h gave a product containing 12.5% crude protein (total N × 6.25) on a dry weight basis. The in vitro rumen digestibility of the 48-h fermentation product was 30%, compared to 24% for the alkali-treated but unfermented sawdust. Growth was independent of sawdust particle size in the range 40 to 100 mesh. Fermentation of the pretreatment liquor gave a product containing up to 50% crude protein (dry weight basis) with an in vitro rumen digestibility of 65 to 76%. Approximately 6.7 g of crude protein was obtained from the treated solids and 2.2 g from the pretreatment liquor per 100 g of sawdust treated. The product from the pretreatment liquor fermentation has potential as a high-protein animal feed supplement but could not be produced economically without an outlet for the relatively indigestible product from the solids fermentation. Growth on the pretreatment liquor was strongly pH dependent; there was a considerable increase in the lag phase when the pH was lowered from 7.5 to 5.2. This effect appears to be due to an inhibitor whose toxicity is reduced at high pH.
Growth of “Seeded” Cellulolytic Enrichment Cultures on Mesquite Wood
Authors: Thayer D. W. , David Carol Ann
Published: January 2020

Eleven enrichment cultures were developed by a “seeded” enrichment culture technique, and one was developed by a simple enrichment technique. The seeded enrichment, the pure “seed,” and the simple enrichment cultures were compared during growth on mesquite wood, cotton, carboxymethylcellulose, and cellobiose. All of the enrichment cultures were cellulolytic and exceeded the pure seed cultures in mesquite wood hydrolysis and/or viable cell count. Yeast extract improved, but was not essential for, growth of the seeded enrichment cultures on carboxymethylcellulose. Two of the seeded enrichment cultures, CAD5 and CAD11, grew best at 37°C and pH 7.0 on mesquite wood. A 1.0% (wt/vol) wood concentration was optimum for their growth.
Measurement and Significance of Specific Activity in the Heterotrophic Bacteria of Natural Waters
Authors: Wright Richard T.
Published: January 2020

It is now possible to obtain accurate total counts of the bacteria of natural waters with the use of acridine orange staining and epifluorescence microscopy. This approach can be coupled to highly sensitive measurements of heterotrophic activity using radioisotopes. To accomplish this, three variations of a “specific activity index” are suggested, based on different approaches to measuring heterotrophic activity with radiolabeled organic solutes. The denominator of each index is the direct count of bacteria from a given natural sample. Three numerators are presented, each of which has been shown to vary directly with heterotrophic bacterial activity:

V
max

, turnover rate, and direct uptake (at high substrate concentrations). Each approach is illustrated with data from estuarine and coastal waters of northeastern Massachusetts. The data show major differences in specific activity that accompany such habitat differences as distances within or offshore from an estuary and vertical location in the water column. These and other data suggest that specific activity is a valid indicator of the physiological state and metabolic role of the bacteria. Some evidence is presented in support of the hypothesis that the natural bacteria are adapted to conditions of nutrient starvation by becoming “dormant,” existing for an unknown period of time in a reversible physiological state that reflects the availability of organic nutrients.
Factors Related to the Oxygen Tolerance of Anaerobic Bacteria
Authors: Rolfe Rial D. , Hentges David J. , Campbell Benedict J. , Barrett James T.
Published: January 2020

The effect of atmospheric oxygen on the viability of 13 strains of anaerobic bacteria, two strains of facultative bacteria, and one aerobic organism was examined. There were great variations in oxygen tolerance among the bacteria. All facultative bacteria survived more than 72 h of exposure to atmospheric oxygen. The survival time for anaerobes ranged from less than 45 min for
Peptostreptococcus anaerobius
to more than 72 h for two
Clostridium perfringens
strains. An effort was made to relate the degree of oxygen tolerance to the activities of superoxide dismutase, catalase, and peroxidases in cell-free extracts of the bacteria. All facultative bacteria and a number of anaerobic bacteria possessed superoxide dismutase. There was a correlation between superoxide dismutase activity and oxygen tolerance, but there were notable exceptions. Polyacrylamide gel electropherograms stained for superoxide dismutase indicated that many of the anaerobic bacteria contained at least two electrophoretically distinct enzymes with superoxide dismutase activity. All facultative bacteria contained peroxidase, whereas none of the anaerobic bacteria possessed measurable amounts of this enzyme. Catalase activity was variable among the bacteria and showed no relationship to oxygen tolerance. The ability of the bacteria to reduce oxygen was also examined and related to enzyme content and oxygen tolerance. In general, organisms that survived for relatively long periods of time in the presence of oxygen but demonstrated little superoxide dismutase activity reduced little oxygen. The effects of medium composition and conditions of growth were examined for their influence on the level of the three enzymes. Bacteria grown on the surface of an enriched blood agar medium generally had more enzyme activity than bacteria grown in a liquid medium. The data indicate that superoxide dismutase activity and oxygen reduction rates are important determinants related to the tolerance of anaerobic bacteria to oxygen.
Occurrence of Yersinia enterocolitica in house rats
Authors: Kaneko K I , Hamada S , Kasai Y , Kato E
Published: January 2020

From July 1976 to May 1977, 270 rats (259 Rattus norvegicus and R. rattus) in Sapporo were examined for the presence of Yersinia enterocolitica in house rats. The organism was isolated in 55 rats (54 R. norvegicus and 1 R. rattus). Isolated strains were determined as O group (O)3, biovar 4; O4, biovar 1; O5A, biovar 1; and O6, biovar 1. The isolation of O3, biovar 4 strains from R. norvegicus is the first in the world, as far as we know. The organism was isolated from the duodenum in 3 rats, the jejunum in 7 rats, the ileum in 8 rats, the cecum in 34 rats, the colon in 23 rats, the rectum in 16 rats, and the mesenteric lymph nodes in 5 rats. The organism was not isolated from liver, spleen, and kidneys. Isolation of the organism from the mesenteric lymph nodes was made in 1 out of 2 O3-positive rats, 1 out of 7 O5A-positive ones, and 3 out of 29 O6-positive ones. A high agglutinin titer was recorded in the two O3-positive rats and in one O6-positive animal.
Occurrence and Ecological Significance of GTP in the Ocean and in Microbial Cells
Authors: Karl D. M.
Published: January 2020

A comparison between the ATP concentrations based on peak height light emission values (0 to 3 s) and integrated light flux determinations (15 to 75 s) for a variety of seawater samples revealed that the integrated method of light detection consistently yielded higher ATP concentrations, ranging from 1.38 to 2.35 times larger than the corresponding peak ATP values. A significant correlation (
r
= 0.923) was observed for a plot of ΔADP (i.e., integrated ATP - peak ATP) versus GTP + UTP, suggesting that the analytical interference on the ATP assay was the result of the presence of non-adenine nucleotide triphosphates. Size-fractionation studies revealed an enrichment of the non-adenine nucleotide triphosphates, relative to ATP, in the smallest size fraction analyzed (<10 μm). Investigations were conducted with 20 species of unicellular marine algae to determine their intracellular nucleotide concentrations, and these determinations were compared to the levels measured in lab cultures of the marine bacterium
Serratia marinorubra
. These results indicated that the intracellular GTP/ATP ratios in
S. marinorubra
increase in direct proportion to the rate of cell growth, and that the GTP/ATP ratios in bacteria are much greater than in growing algae, presumably due to the differences in rates of cellular biosynthesis. It is concluded that quantitative determinations of GTP/ATP ratios in environmental sample extracts may be useful for measuring microbial growth.
Establishment of a heat inactivation curve for Clostridium botulinum 62A toxin in beef broth
Authors: Losikoff M E
Published: January 2020

A procedure is described for establishing a heat inactivation curve for the toxin of Clostridium botulinum 62A in beef broth. The effect of toxin titer, pH, and the type of acid employed for pH adjustment on the heat stability of the toxin is described.
Detection of staphylococcal enterotoxins A, B, C, D, and E in foods by radioimnunoassay, using staphyloccal cells containing protein A as immunoadsorbent
Authors: Miller B A , Reiser R F , Bergdoll M S
Published: January 2020

A sensitive radioimmunoassay utilizing Staphylococcus aureus cells containing protein A as a coprecipitant was developed for the detection and quantitation of staphylococcal enterotoxins A, B, C, D, and E in a variety of foods. The enterotoxins were extracted from the foods by a simple and rapid procedure. The sensitivity of the assay is 1.0 ng or less of enterotoxin per g of food.
Enchanced accuracy of coliform testing in seawater by a modification of the most-probable-number method
Authors: Olson B H
Published: January 2020

A 1-year study of marine water sample from six beach locations showed that the most-probable-number method failed to recover significant numbers of coli-forms. Modifying this method by transferring, after 48 h, presumptive negatives (growth and no gas production) to confirmed and fecal coliform media significantly improved recovery. Tests which were presumptive negative but confirmed as fecal coliform positive were designated as false negatives. Most-probable-number method false negatives occurred throughout the year, with 143 of 270 samples collected producing false negatives. More than 50% of fecal coliform false-negative isolates were Escherichia coli. Inclusion of false-negative tubes into the coliform most-probable-number method data resulted in increased violation of the California ocean water contact sports standard at all sites. More than 20% of the samples collected were in violation of this standard. These data indicate that modification of the most-probable-number method increases detection of coliform numbers in the marine environment.
Antibiotic resistance patterns of gram-negative bacteria isolated from environmental sources
Authors: Kelch W J , Lee J S
Published: January 2020

A total of 2,445 gram-negative bacteria belonging to fecal coliform, Pseudomonas, Moraxella, Acinetobacter, and Flavobacterium-Cytophaga groups were isolated from the rivers and bay of Tillamook, Oregon, and their resistances to chloramphenicol (25 microgram/ml), streptomycin (10 microgram/ml), ampicillin (10 microgram/ml), tetracycline (25 microgram/ml), chlortetracycline (25 microgram/ml), oxytetracycline (25 microgram/ml), neomycin (50 microgram/ml), nitrofurazone (12.5 microgram/ml), nalidixic acid (25 microgram/ml), kanamycin (25 microgram/ml), and penicillin G (10 IU/ml) were determined. Among fecal coliforms the bay isolates showed greater resistance to antibiotics than those from tributaries or surface runoff. No such well-defined difference was found among other bacterial groups. The antibiotic resistance patterns of gram-negative bacteria from different sources correlated well, perhaps indicating their common origin. The antibiotic resistance patterns of gram-negative bacteria of different general also correlated well, perhaps indicating that bacteria which share a common environment also share a common mode for developing antibiotic resistance.
Effect of phosphate buffer concentration on the heat resistance of Bacillus stearothermophilus spores suspended in parenteral solutions
Authors: Gauthier C A , Smith G M , Pflug I J
Published: January 2020

The effect of various quantities of Butterfield phosphate buffer added to four parenteral solutions on the survival of Bacillus stearothermophilus spores heated at 121 degrees C was determined. The effect of the addition of phosphate buffer on spore survival varied with the parenteral solution. Spore survival was increased or decreased, depending upon the composition of the parenteral solution and the buffer concentration. The results obtained in these experiments attest to the fact that environmental factors, including the type of ions present and ionic concentration, affect the heat destruction rate of B. stearothermophilus spores. Therefore, the sterilization requirements of a product such as a parenteral solution may be affected by small changes in formulation.
Deodorization of pig feces by actinomycetes
Authors: Ohta Y , Ikeda M
Published: January 2020

Peg feces, a malodorous substance causing environmental pollution, were completely deodorized within 2 days by Streptomyces. The optimum conditions for deodorization were as follows: pH, 8.6 to 10; temperature, 35 to 40 degrees C; moisture content, 42 to 63%; and minimum amount of inoculum, 2 g of seed culture per 10 g of fresh feces. Many kinds of microorganisms were isolated from the deodorized feces, of which only actinomycetes were found to have the ability to deodorize. Two strains with strong deodorizing activity were identified as Streptomyces griseus and Streptomyces antibioticus. The low-molecular-weight fatty acids, which are the specific malodorous agents of pig feces, scarcely could be found in feces deodorized by the isolated strains. Chemical analysis showed that the deodorized feces are useful as manure.
Ecological relationship between Vibrio parahaemolyticus and agar-digesting vibrios as evidenced by bacteriophage susceptibility patterns
Authors: Baross J A , Liston J , Morita R Y
Published: January 2020

Twenty bacteriophages active against Vibrio parahaemolyticus and agar-digesting vibrios, isolated from oysters (Crassostrea gigas) and Dungeness crab (Cancer magister) and by induction of a lysogenic agar digester, were tested as to their host range. These phages were specific for V. parahaemolyticus and various agar-digesting vibrios, and interspecies lysis occurred only between these two groups. V. alginolyticus, V. anguillarum and related species, V. cholerae, and a group of marine psychrophilic and psychrotrophic vibrios were not affected. No correlation was observed between the O and K serotypes of V. parahaemolyticus strains and bacteriophage susceptibility patterns, and 7 of 28 strains of V. parahaemolyticus were not lysed by any of the phages. Only two of the phage isolates were capable of lysing all susceptible V. parahaemolyticus strains. No correlation was observed between the inter-and intraspecies genetic relatedness (DNA homologies) of V. parahaemolyticus and agar-digesting vibrios and susceptibility patterns to different bacteriophages. Some of the phages were capable of plaque formation on V. parahaemolyticus as well as on some strains of agar-digesting vibrios that were separated by 70 to 80% differences in their DNA homologies. The possible ecological significance of these vibrio bacteriophages, particularly those having a wide host range, is discussed.
Rumen Protozoal Degradation of Structurally Intact Forage Tissues
Authors: Amos Henry E. , Akin Danny E.
Published: January 2020

The association with and digestion of intact leaf sections of cool- and warm-season grasses by cattle rumen protozoa were investigated by light and scanning electron microscopy and by in vitro dry matter disappearance studies. Within extensively degraded areas of mesophyll tissue in cool-season forages, almost all protozoa were
Epidinium ecaudatum
form
caudatum
, with maximum numbers at 4 to 10 h of incubation. However, few protozoa were found inside warm-season forage leaves. In in vitro dry matter disappearance studies of a series of incubations with and without 1.6 mg of streptomycin per ml, which inhibited the cellulolytic activity of the bacteria, and in comparison with uninoculated controls, rumen protozoa degraded 11.0 and 3.7 percentage units of orchardgrass and bermuda-grass, respectively. Scanning electron microscopy showed that the tissues degraded in orchardgrass consisted of large amounts of mesophyll and portions of the parenchyma bundle sheath and epidermis; no tissue loss due to the protozoa was observed in bermudagrass. The relationship of these observations to forage digestion is discussed.
Efficiency of beef extract for the recovery of poliovirus from wastewater effluents
Authors: Landry E F , Vaughn J M , Thomas M Z , Vicale T J
Published: January 2020

The efficiency of poliovirus elution from fiber glass cartridge filters (K27), epoxy-fiber glass-asbestos filters (M780), and pleated cartridge filters was assessed by using 3% beef extract (pH 9.0) or 0.1 M glycine (pH 11.5). Poliovirus type I, strain LSc, was seeded into 20- to 25-gallon (ca. 75.6- to 95.6-liter) samples of treated sewage effluent and concentrated by using a filter adsorption-elution technique. Virus elution was accomplished by using either two 600-ml portions of 3% beef extract (pH 9.0), or two 1-liter portions of 0.1 M glycine (pH 11.5). In all experiments, beef extract elution followed by organic flocculation was found to be superior, yielding a mean recovery efficiency of 85%, with recoveries ranging from 68 to 100%. Elution with 0.1 M glycine (pH 11.5) followed by inorganic flocculation resulted in a mean recovery efficiency of 36%. The variable range of recoveries with beef extract could not be significantly improved by varying the type of beef extract or by extending the elution time to 30 min. Second-step reconcentration of 1-liter seeded sewage effluent and renovated wastewater samples indicated that organic flocculation was a more efficient method for virus recovery than inorganic flocculation. Beef extract concentrations of less than 3% were found to be efficient in the recovery of poliovirus from renovated wastewater.
Production of xanthomegnin and viomellein by isolates of Aspergillus ochraceus, Penicillium cyclopium, and Penicillium viridicatum
Authors: Stack M E , Mislivec P B
Published: January 2020

Fungal isolates from legumes were cultured on rice and examined for production of the toxic mold metabolites xanthomegnin and viomellein. Six of 14 Aspergillus ochraceus isolates produced from 0.3 to 1.3 mg of xanthomegnin per g and 0.1 to 1.0 mg of viomellein per g. One of nine isolates of Penicillium cyclopium produced 0.1 mg of xanthomegnin per g and 0.06 mg of viomellein per g. Three of nine P. viridicatum isolates produced from 0.4 to 1.6 mg of xanthomegnin per g and 0.2 to 0.4 mg of viomellein per g. This is the first report of xanthomegnin and viomellein production by A. ochraeus and P. cyclopium.
Medium for the Enumeration and Isolation of Bacteria from a Swine Waste Digester
Authors: Iannotti E. L. , Fischer J. R. , Sievers D. M.
Published: January 2020

A habitat-simulating medium was developed for the enumeration and isolation of bacteria from a swine waste digester. A roll tube medium with growth factors for strict anaerobes from previously studied anaerobic ecosystems was used to evaluate the effects of deletion, addition, or level of digester fluid, digester fluid treated with acid or base, rumen fluid, fecal extract, anaerobic pit extract, tissue extract, carbohydrates, peptones, short-chain fatty acids, minerals, vitamins, N and P sources, reducing and solidifying agents, buffers, and gases on colony counts. Decreasing the agar concentration from 2.5 to 1.0% increased the counts twofold. Blending increased the counts 1.7-fold. With a medium (174) containing digester fluid, peptones, minerals, cysteine, sodium carbonate, and agar, colony counts were 60% of the microscopic count and improved yields 2.5 to 20 times those obtained with media previously used for digesters or developed for other anaerobic ecosystems. Colony counts continued to increase for up to 4 weeks of incubation. Medium 174 permits the enumeration of total, methanogenic, and, with deletion of reducing agent, aerotolerant bacteria. The results suggest that the predominant bacteria grow slowly and have requirements different from those of bacteria from other ecosystems.
Isolation, purification, and antibiotic activity of o-methoxycinnamaldehyde from cinnamon
Authors: Morozumi S
Published: January 2020

o-Methoxycinnamaldehyde has been isolated and purified from powdered cinnamon. The compound inhibits the growth and toxin production of mycotoxin-producing fungi. The substance completely inhibited the growth of Aspergillus parasiticus and A. flavus at 100 microgram/ml and A. ochraceus and A. versicolor at 200 microgram/ml. It inhibited the production of aflatoxin B1 by over 90% at 6.25 microgram/ml, ochratoxin A at 25 microgram/ml, and sterigmatocystin at 50 microgram/ml. The substance also displayed a strong inhibitory effect on the growth of five dermatophytoses species, e.g., Microsporum canis (minimum inhibitory concentration, 3.12 to 6.25 microgram/ml). However, no antibacterial effect was observed at concentrations as high as 50 microgram/ml.
Diversity in the Ammonia-Oxidizing Nitrifier Population of a Soil
Authors: Belser L. W. , Schmidt E. L.
Published: January 2020

Multiple genera of ammonia-oxidizing chemoautotrophic nitrifiers in a soil were detected, isolated, and studied by means of modified most-probable-number (MPN) techniques. The soil examined was a Waukegon silt loam treated with ammonium nitrate or sewage effluent. The genera
Nitrosomonas
and
Nitrosospira
were found to occur more commonly than the genus
Nitrosolobus.
Three different MPN media gave approximately the same overall ammonia oxidizer counts within statistical error after prolonged incubation but differed markedly in ratios of
Nitrosomonas
to
Nitrosospira.
Selectivity and counting efficiency of MPN media were studied by observing the growth response of representative pure cultures isolated from the soil. Selectivity was evident in each medium with respect to all strains tested, and the media differed greatly in incubation times required to obtain maximum counts.
Ochratoxin A: Isolation and Subsequent Purification by High-Pressure Liquid Chromatography
Authors: Peterson R. E. , Ciegler A.
Published: January 2020

A purification method for ochratoxin A, using liquid-liquid extractions and a final cleanup by high-pressure liquid chromatography, is described.
Flow microfluorometry study of diauxic batch growth of Saccharomyces cerevisiae
Authors: Gilbert M F , McQuitty D N , Bailey J E
Published: January 2020

Flow microfluorometry reveals complex changes in types and relative numbers of different Saccharomyces cerevisiae cell forms during glucose-limited diauxic batch growth.
Toxicological model for a two-acid system
Authors: Rubin H E
Published: January 2020

Lactic and acetic acids were determined to be slightly synergistic in their inhibitory interrelationship against Salmonella typhimurium with the use of a modified toxicological model.
Factors Affecting the Activity of Cellulases Isolated from the Rumen Digesta of Sheep
Authors: Francis G. L. , Gawthorne J. M. , Storer G. B.
Published: January 2020

Sodium phosphate buffer was used to extract cellulases from the plant solids fraction of rumen contents. The mixed cellulase preparation had maximal activity at pH 6.9 and 49°C. The V

max

and the apparent K

m

for wheaten hay cellulose were 19.8 glucose units/min and 6.35 mg/ml, respectively, and for microcrystalline cellulose (Sigmacell) at the same enzyme concentration, they were 33 glucose units/min and 27.5 mg/ml, respectively. For these assays a glucose unit was defined as nanomoles of glucose plus twice the nanomoles of cellobiose. Consideration of thermodynamic and kinetic data suggested that the hydrolysis of a relatively labile arabino-xylan comprising 3% of the wheaten hay cellulose was dependent on prior removal of the protecting β-1,4-glucose chains at the outer surface of the cellulose preparation. Sequential removal of structural polysaccharides from the plant cell wall rendered the latter more susceptible to cellulase activity. Cellulase activity was stimulated by increasing the concentration of phosphate from 5 to 50 mM. The stimulation was magnified in the presence of cell-free rumen fluid. Cellulase activity was not stimulated by calcium, magnesium, iron, zinc, manganese, copper, or cobalt ions and was unaffected by the chelators ethylenediaminetetraacetic acid and ethyleneglycol-bis (β-aminoethyl ether)-
N,N′
-tetraacetic acid.
O
-phenanthroline inhibited activity by 30 to 50%, but this may have been due to nonchelate properties. Anaerobic conditions or thiol protective agents were not essential for either the activity or stability of the cellulases during assay. An ultrafiltrable inhibitor of cellulase activity was detected in cell-free rumen fluid.
Light inhibits the production of alternariol and alternariol monomethyl ether in Alternaria alternata
Authors: Söderhäll K , Svensson E , Unestam T
Published: January 2020

Alternaria alternata (Fr.) Keissler, grown in drop culture, produced alternariol and alternariol monomethyl ether in late growth phase. Production was almost completely inhibited when the fungal cultures were exposed to white light (180 W/m2), although mycelial dry weight was not significantly affected. The fungus was most sensitive to light during the exponential growth phase. Twelve hours of light exposure was sufficient to decrease significantly the production of the secondary metabolites. In light the fungus produced a red-brown pigment of unknown nature.
Microbiological and Physical Properties of Salt Marsh and Microecosystem Sediments
Authors: Reichgott Michael , Stevenson L. Harold
Published: January 2020

Sediments from natural marsh and four microecosystem (MES) tanks were compared with reference to ATP, carbon content, and physical properties. Mean values for bacterial numbers and ATP were about twice as high in the MES, carbon content was slightly higher in the artificial systems, and the sediment of the MES was enriched for larger grain sizes and depleted of silt and clay. In the natural marsh sediment, ATP was strongly related (Pearson's correlation coefficient) to granulometric (or physical) factors, whereas ATP was related to biological factors in the MES. Approximately 61% of the variation in ATP concentrations in the marsh sediments could be accounted for by the parameters measured. Only half that amount could be explained on the basis of those same variables in the MES. Furthermore, one of the four tanks was significantly different from the other three in terms of ATP concentration, and an anomaly in respect to silt-clay content was demonstrated in another. Careful control and some type of equilibrating procedure will be necessary before the MES can be employed as replicate units.
Phosphorus-containing pesticide breakdown products: quantitative utilization as phosphorus sources by bacteria
Authors: Cook A M , Daughton C G , Alexander M
Published: January 2020

Bacteria were isolated that could utilize representatives of the following ionic phosphorus-containing breakdown products of organophosphorus pesticides as sole phosphorus sources: dialkyl phosphates, dialkyl phosphorothioates, dialkyl phosphorodithioates, alkyl arylphosphonates, alkyl arylphosphonothioates, and alkyl alkylphosphonates. Utilization of each organophosphorus compound, which was complete for 7 of 12 compounds studied, was confirmed by determination of protein yield from the amount of phosphorus source consumed. This is the first report of the utilization of an ionic dialkyl thiophosphate or dithiophosphate by microorganisms.
Microbial degradation of glycerol nitrates
Authors: Wendt T M , Cornell J H , Kaplan A M
Published: January 2020

The fate of glycerol trinitrate when exposed to microbial attack has been investigated. Contrary to some earlier reports, this compound was readily biodegraded by employing batch or continuous techniques under a variety of cultural conditions. Breakdown of glycerol trinitrate took place stepwise via the dinitrate and mononitrate isomers, with each succeeding step proceeding at a slower rate. After a residence time of 8 to 15 h, none of the glycerol nitrates could be detected in the effluent from a continuous-culture apparatus (chemostat) supplied with an influent containing 30 mg of glycerol trinitrate per liter.
Prevalence and distribution of Aeromonas hydrophila in the United States
Authors: Hazen T C , Fliermans C B , Hirsch R P , Esch G W
Published: January 2020

The abundance of Aeromonas hydrophila was measured in 147 natural aquatic habitats in 30 states and Puerto Rico. Viable cell counts were used to estimate density at all sites by using Rimler-Shotts medium, a differential presumptive medium for A. hydrophila. Temperature, pH, conductivity, salinity, and turbidity were measured simultaneously with water sample collection. The density of A. hydrophila was higher in lotic than in lentic systems. Saline systems had higher densities of A. hydrophila than did freshwater systems. A. hydrophila could not be isolated from extremely saline, thermal, or polluted waters, even though it was found over wide ranges of salinity, conductivity, temperature, pH, and turbidity. Of the water quality parameters measured, only conductivity was significantly regressed with density of A. hydrophila.
Enumeration, Isolation, and Characterization of
Beggiatoa
from Freshwater Sediments
Authors: Strohl William R. , Larkin John M.
Published: January 2020

An accurate most-probable-number enumeration method was developed for counting the number of
Beggiatoa
trichomes from various freshwater sediments. The medium consisted of extracted hay, diluted soil extract, 0.05% acetate, and 15 to 35 U of catalase per ml. The same enrichment medium, but without the acetate, was the best enrichment medium from which to obtain pure cultures because it supported good growth of the beggiatoas without allowing them to be overgrown by other bacteria. A total of 32 strains of
Beggiatoa
were isolated from seven different freshwater habitats and partially characterized. The strains were separated into five groups based on several preliminary characteristics. Four of the groups contained cells with trichomes of approximately the same diameter (1.5 to 2.7 μm) and may be
Beggiatoa leptomitiformis
or an unnamed species. The fifth group appeared to be
Beggiatoa alba.
With the exception of three strains, all of the strains deposited sulfur in the presence of hydrogen sulfide, and all strains grew heterotrophically and deposited poly-β-hydroxybutyrate and volutin when grown on acetate supplemented with low concentrations of other organic nutrients. Thin sections of sulfur-bearing trichomes indicated that the sulfur granules were external to the cytoplasmic membrane and that they were surrounded by an additional membrane.
Antiviral effect of apple beverages
Authors: Konowalchuk J , Speirs J I
Published: January 2020

A variety of apple beverages were tested for antiviral activity against poliovirus 1 or coxsackievirus B5. Freshly prepared apple juice was particularly antiviral, but its activity declined more readily than that of commercial juice in response to heat and storage. The component responsible for activity was located both in the pulp and skin; after ultrafiltration, activity was present in fractions greater and less than molecular weight 10,000. Virus infectivity was not restored from virus-apple juice complexes with gelatin, serum, Tween 80, or polyethylene glycol.
Production, characterization, and partial amino acid sequence of xylanase A from Schizophyllum commune
Authors: Paice M G , Jurasek L , Carpenter M R , Smillie L B
Published: January 2020

Xylanase A, one of several extracellular xylanases produced by Schizophyllum commune strain Delmar when grown in submerged culture with spruce sawdust as carbon source, was purified 43-fold in 25% yield with respect to total xylanase activity. Although some polysaccharide was strongly bound to the purified enzyme, the complex could be dissociated by sodium dodecyl sulfate and appeared homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the protein, calculated from the electrophoretic mobility, was 33,000. The molecular activity of the purified xylanase A, determined with soluble larch xylan as substrate, was 1.4 X 10(5) min-1, with xylobiose and xylose as the major products. The enzyme had a pH optimum of 5.0 and a temperature optimum of 55 degrees C in 10-min assays. The acid hydrolysate of xylanase A was rich in aspartic acid and aromatic amino acids. The sequence of 27 residues at the amino terminus showed no homology with known sequences of other proteins.
Injury to Staphylococcus aureus during sausage fermentation
Authors: Smith J L , Palumbo S A
Published: January 2020

Staphylococcus aureus 196E added to a beef sausage containing starter culture and 0.5 to 2.0% glucose and incubated at 35 degrees C was unable to grow when plated on tryptic soy agar (TSA) containing 7.5% NaCl. The injury, presumed to be due to the lactic acid produced during fermentation, was more pronounced at the lower concentrations of glucose (and lower acid levels). In the absence of glucose and/or starter culture, no injury was observed. When sausages containing S. aureus injured by fermentation at 35 degrees C were incubated at 5 degrees C, the counts on TSA (measures both injured and uninjured cells) and TSA containing 7.5% NaCl (measures uninjured cells only) remained constant; however, upon reincubation of the cold-stored sausage at 35 degrees C, the staphylococcus counts on TSA and TSA containing 7.5% NaCl and were similar to the counts of S. aureus present in fermenting sausages that had never been subjected to 5 degrees C. The demonstration of acid injury indicated that the injury phenomenon must be considered when determining numbers of viable S. aureus in fermented sausages.
Validity of fecal coliforms, total coliforms, and fecal streptococci as indicators of viruses in chlorinated primary sewage effluents
Authors: Berg G , Dahling D R , Brown G A , Berman D
Published: January 2020

Quantities of combined chlorine that usually destroyed more than 99.999% of the indigenous fecal coliforms, total coliforms, and fecal streptococci in primary sewage effluents destroyed only 85 to 99% of the indigenous viruses present. Viruses were recovered from five of eight chlorinated primary effluents from which fecal coliforms were not recovered by standard most-probable-number procedures. The limited volumes of such chlorinated effluents that can be tested for indicator bacteria with currently available multiple-tube and membrane filter techniques restrict the value of fecal coliforms, fecal streptococci, and even total coliforms as indicators of viruses in these effluents. Although fecal coliforms and fecal streptococci are useful indicators of viruses in effluents from which these bacteria are recovered, the absence of these bacteria and even total coliforms from disinfected effluents (in standard tests) does not assure that viruses are also absent.
Survey of 1977 crop year preharvest corn for vomitoxin
Authors: Vesonder R F , Ciegler A , Rogers R F , Burbridge K A , Bothast R J , Jensen A H
Published: January 2020

Fifty-two preharvest corn samples were collected in mid-October 1977 from 26 farms in a four-county area of northwest Ohio. Vomitoxin ranging from 0.5 to 10 microgram/g was found in 24 of the samples. Analysis for vomitoxin was by gas-liquid chromatography. Preceding harvest in northwest Ohio, unusual wet conditions prevailed, making it favorable for Fusarium growth. Gibberella zeae-infected kernels ranged from 2 to 50% of the kernels analyzed for 44 corn samples, and 8 corn samples showed no infection.
Genetically marked Rhizobium identifiable as inoculum strain in nodules of soybean plants grown in fields populated with Rhizobium japonicum
Authors: Kuykendall L D , Weber D F
Published: January 2020

The fate of an inoculum strain of Rhizobium japonicum was studied using a genetically marked strain I-11O subline carrying resistance markers for azide, rifampin, and streptomycin (I-110 ARS). At the time of planting into a field populated with R. japonicum, seeds of soybean cultivars Kent and Peking were inoculated with varying cell densities of strain I-110 ARS. At various times during the growing season, surface-sterilized root nodules were examined for the presence of the inoculum strain by plating onto selective media. The recovery of the inoculum strain was unambiguous, varying, in the case of Kent cultivar, from about 5% with plants (sampled at 51 days) that had been inoculated with 3 X 10(8) cells per cm of row to about 20% with plants (sampled at 90 days) that had been inoculated with 3 X 10(9) cells per cm. The symbiotically incompatible interaction of Peking and strain 110 in Rhizobium-populated field soil was confirmed by the finding that at 60 days after planting, only one nodule in 360 sampled contained strain I-110 ARS. The use of genetically marked Rhizobium bacteria was found to provide for precise identification of the inoculum strain in nodules of field-grown soybeans.
Isolation and Characterization of Plasmid DNA in
Streptococcus cremoris
Authors: Larsen L. D. , McKay L. L.
Published: January 2020

Nine industrially important strains of
Streptococcus cremoris
(HP, AM
2
, ML
1
, WC, C
3
, R
1
, E
8
, KH, and Wg
2
) were shown to possess a diversity of plasmid molecules. Molecular weights of plasmids were determined from their relative mobilities after agarose gel electrophoresis and via electron microscopy. To illustrate the varied plasmid sizes, strain HP contained plasmids of 26, 18, 8.5, 3.3, and 2 megadaltons (Mdal); strain ML
1
contained plasmids of 29, 18, 9, 4, 2.2, and 1.8 Mdal; and strain AM
2
had plasmids of 42, 27, 16, and 8.4 Mdal. The numbers of plasmids observed in the other strains were 6, 5, 5, 7, 5, and 4 for C
3
, E
8
, KH, R
1
, WC, and Wg
2
, respectively. A spontaneous proteinase-negative (Prt
−
) mutant of HP was missing the 8.5-Mdal plasmid, which suggests that in this strain proteinase activity could be linked to this particular plasmid. A lactose-negative (Lac
−
) Prt
−
mutant of ML
1
lacked the 2.2-Mdal plasmid. Under the conditions employed, antibiotic sensitivity and heavy-metal susceptibility did not correlate with the missing plasmid in Prt
−
HP or in the Lac
−
Prt
−
ML
1
. Curing experiments with AM
2
, using acridine dyes and elevated temperatures, did not yield Lac
−
variants. AM
2
was also cultured at high dilution rates in a chemostat for 168 h by using a buffered milk or lactic broth at 18 or 32°C with no selection of Lac
−
derivatives. The inability to obtain Lac
−
variants under conditions known to facilitate plasmid elimination suggests that lactose metabolism is not plasmid-mediated in AM
2
.
New monitoring system for proteolysis in soil as influenced by selected herbicidal applications
Authors: Cullimore D R , Ball L
Published: January 2020

Proteolysis in soil (Regina heavy clay) was monitored by the gelatinolytic etching of developed color film emulsion, using a film immersion-slide carrier technique. Etching followed a sigmoid curve to completion. A total of 11 herbicides were tested for their potential influence on this proteolytic function. Eight caused some inhibition, and two were stimulative at 200 microliter of applied herbicide per liter. Eptam was found to stimulate at low concentrations and inhibit at higher concentrations (greater than 1,000 microliter of applied Eptam per liter).
Two stomacher accessories
Authors: Sharpe A N , Dudas I
Published: January 2020

Two useful and easily constructed accessories for the Colworth Stomacher blender are described. The first automatically opens and holds Stomacher bags above a balance of weighing in the sample. The second stores bags on the bench between manipulations and opens and holds them as required for pipetting, etc.