bluuebunny/crossref_metadata_2025 huggingface dataset:
Occurrence of a Lysogenic
Streptomyces
sp. on the Nodule Surface of Black Gram (
Vigna mungo
(L.) Hepper)
Authors: Rangarajan M. , Ravindran A. David , Hariharan K.
Published: January 2020

A lysogenic
Streptomyces
sp., strain NS.A4, which was isolated from the nodule surface of black gram (
Vigna mungo
(L.) Hepper), was found to inhibit rhizobia of fast-and slow-growing strains of cowpeas and soybeans. It exhibited plaques when there was a change in cultural conditions. Repeated culturing of the organism in nutrient agar and broth confirmed the infection of
Streptomyces
sp. strain NS.A4 by an actinophage. Addition of the culture filtrate of
Streptomyces
sp. strain NS.A4 to shaken broth cultures of three other
Streptomyces
spp. resulted in phage infection.
Fast-Growing
Rhizobium japonicum
That Effectively Nodulates Several Commercial
Glycine max
L. Merrill Cultivars
Authors: Hattori Jiro , Johnson Douglas A.
Published: January 2020

Several isolates of fast-growing
Rhizobium japonicum
that nodulate the wild soybean
Glycine soja
have been recently described (Keyser et al., Science 215:1631-1632, 1982). We demonstrate that one of these isolates, designated PRC 440 or USDA 191, has a wider host range than that previously reported and is able to nodulate several commercial
Glycine max
cultivars as effectively as does slow-growing
R. japonicum
61A76. Electron microscopic examination revealed no obvious differences between strain 61A76- and strain USDA 191-induced nodules.
Halophilic Vibrio species from seafish in Senegal
Authors: Schandevyl P , Van Dyck E , Piot P
Published: January 2020

Sucrose-positive and sucrose-negative halophilic Vibrio species at counts of up to 10(7)/100 g were isolated from muscles tissue in 27 and 43%, respectively, of 128 seafish from coastal waters in Senegal. Vibrio parahaemolyticus, including 21% urease-positive strains, was the most common isolate, followed by Vibrio alginolyticus, Vibrio vulnificus, Vibrio damsela, and Vibrio fluvialis.
Proline transport increases growth efficiency in salt-stressed Streptomyces griseus
Authors: Killham K , Firestone M K
Published: January 2020

Streptomyces griseus synthesizes proline for osmoregulation under salt stress. Uptake of exogenous [14C]proline and internal synthesis of proline were quantified in cells growing at salt concentrations from 0 to 1 M NaCl. Externally supplied proline accounted for an increased proportion of the intracellular pool of free proline as salt concentration was increased, but neither the concentration nor the composition of the internal amino acid pool was substantially altered by supply of exogenous proline. Uptake of exogenous proline significantly increased the specific growth yield of S. griseus growing under salt stress; the increased yield was proportional to reductions in proline synthesis.
Effect of chlorination on antibiotic resistance profiles of sewage-related bacteria
Authors: Murray G E , Tobin R S , Junkins B , Kushner D J
Published: January 2020

A total of 1,900 lactose-fermenting bacteria were isolated from raw sewage influent and chlorinated sewage effluent from a sewage treatment plant, as well as from chlorinated and neutralized dilute sewage, before and after a 24-h regrowth period in the laboratory. Of these isolates, 84% were resistant to one or more antibiotics. Chlorination of influent resulted in an increase in the proportion of bacteria resistant to ampicillin and cephalothin, the increase being most marked after regrowth occurred following chlorination. Of the other nine antibiotics tested, chlorination resulted in an increased proportion of bacteria resistant to some, but a decrease in the proportion resistant to the remainder. Multiple resistance was found for up to nine antibiotics, especially in regrowth populations. Identification of about 5% of the isolates showed that the highest proportion of Escherichia coli fell in untreated sewage. Some rare and potentially pathogenic species were isolated from chlorinated and regrowth samples, including Yersinia enterocolitica, Yersinia pestis, Pasteurella multocida, and Hafnia alvei. Our results indicate that chlorination, while initially lowering the total number of bacteria in sewage, may substantially increase the proportions of antibiotic-resistant, potentially pathogenic organisms.
Isolation and Characterization of an Anaerobic, Cellulolytic Bacterium,
Clostridium cellulovorans
sp. nov
Authors: Sleat Robert , Mah Robert A. , Robinson Ralph
Published: January 2020

A new anaerobic, mesophilic, spore-forming cellulolytic bacterium is described. Cellulose is cleared within 24 to 48 h around colonies formed in cellulose agar roll tubes. Cells stain gram negative and are nonmotile rods which form oblong spores either centrally or subterminally in a clostridial swelling. Colonies are irregular with an opaque edge and a center devoid of both vegetative cells and spores. Cellulose, xylan, pectin, cellobiose, glucose, maltose, galactose, sucrose, lactose, and mannose serve as substrates for growth. H
2
, CO
2
, acetate, butyrate, formate, and lactate are produced during fermentation of cellulose or cellobiose. The temperature and pH for optimum growth are 37°C and 7.0, respectively. The DNA composition is 26 to 27 mol% guanine plus cytosine. This bacterium resembles “
Clostridium lochheadii
” in morphological and some biochemical characteristics but is not identical to it. The name
Clostridium cellulovorans
sp. nov. is proposed. The type strain is 743B (ATCC 35296).
Evaluation of a fluorogenic assay for detection of Escherichia coli in foods
Authors: Robison B J
Published: January 2020

A fluorogenic assay procedure with 4-methylumbelliferyl-beta-D-glucuronide incorporated into lauryl sulfate broth was evaluated to detect and confirm the presence of Escherichia coli in foods. Fluorescence is indicative of the presence of E. coli; extensive biochemical confirmation is unnecessary with this assay. The 4-methylumbelliferyl-beta-D-glucuronide assay was tested concurrently with our present methodology for detection of E. coli on 270 samples of raw ingredients and powdered food products. Total agreement between the two methods was 94.8%; there was a false-positive rate of 4.8% and no false-negatives. We found the 4-methylumbelliferyl-beta-D-glucuronide assay to be rapid, accurate, simple to perform, and inexpensive.
Inactivation of simian rotavirus SA11 by chlorine, chlorine dioxide, and monochloramine
Authors: Berman D , Hoff J C
Published: January 2020

The kinetics of inactivation of simian rotavirus SA11 by chlorine, chlorine dioxide, and monochloramine were studied at 5 degrees C with a purified preparation of single virions and a preparation of cell-associated virions. Inactivation of the virus preparations with chlorine and chlorine dioxide was studied at pH 6 and 10. The monochloramine studies were done at pH 8. With 0.5 mg of chlorine per liter at pH 6, more than 4 logs (99.99%) of the single virions were inactivated in less than 15 s. Both virus preparations were inactivated more rapidly at pH 6 than at pH 10. With chlorine dioxide, however, the opposite was true. Both virus preparations were inactivated more rapidly at pH 10 than at pH 6. With 0.5 mg of chlorine dioxide per liter at pH 10, more than 4 logs of the single-virus preparation were inactivated in less than 15 s. The cell-associated virus was more resistant to inactivation by the three disinfectants than was the preparation of single virions. Chlorine and chlorine dioxide, each at a concentration of 0.5 mg/liter and at pH 6 and 10, respectively, inactivated 99% of both virus preparations within 4 min. Monochloramine at a concentration of 10 mg/liter and at pH 8 required more than 6 h for the same amount of inactivation.
Regulation of product formation during glucose or lactose limitation in nongrowing cells of Streptococcus lactis
Authors: Fordyce A M , Crow V L , Thomas T D
Published: January 2020

Nongrowing cells of Streptococcus lactis in a pH-stat were dosed with sugar to allow fermentation at the maximum rate or were fed a continuous supply of sugar at rates less than the maximum. Under anaerobic conditions, rapid fermentation of either glucose or lactose was essentially homolactic. However, with strain ML3, limiting the fermentation rate diverted approximately half of the pyruvate to formate, acetate, and ethanol. At limiting glucose fermentation rates, cells contained lower concentrations of lactate dehydrogenase activator (fructose 1,6-diphosphate) and pyruvate formate-lyase inhibitors (triose phosphates). As a result, pyruvate formate-lyase and pyruvate dehydrogenase play a greater role in pyruvate metabolism. In contrast to strain ML3, strain ML8 did not give the same diversion of products under anaerobic conditions, and cells retained higher concentrations of the above effector compounds. Lactose metabolism under aerobic conditions resulted in pyruvate excretion by both S. lactis ML3 and ML8. At 7% of the maximum utilization rate, pyruvate accounted for 69 and 35% of the lactose metabolized by ML3 and ML8, respectively. Acetate was also a major product, especially with ML8. The data suggest that NADH oxidase is involved in coenzyme recycling in the presence of oxygen and that pyruvate formate-lyase is inactivated, but the pyruvate dehydrogenase complex still functions.
Microbial flora of in-use soap products
Authors: McBride M E
Published: January 2020

A comparison has been made of the in-use bacterial load of two bar soaps with and without antibacterials and two liquid soaps in five different locations over a 1-week period. Of the 25 samples taken from each soap, 92 to 96% of samples from bar soaps were culture positive as compared to 8% of those from liquid soaps. Bacterial populations ranged from 0 to 3.8 log CFU per sample for bar soaps and from 0 to 2.0 log CFU per sample for liquid soaps. The mean bacterial populations per sample were 1.96 and 2.47 log CFU for the two bar soaps, and 0.08 and 0.12 log CFU for the two liquid soaps. The difference in bacterial population between bar soaps and liquid soaps was statistically significant (P = 0.005). Staphylococcus aureus was isolated on three occasions from bar soaps but not from liquid soaps. S. aureus was isolated twice from the exterior of the plastic dispensers of liquid soap but not from the soap itself. Gram-negative bacteria were cultured only from soaps containing antibacterials. Bacterial populations on bar soaps were not high compared with bacterial populations on hands, and the flora was continually changing without evidence of a carrier state.
Molecular cloning of the lactose-metabolizing genes from Streptococcus lactis
Authors: Harlander S K , McKay L L , Schachtele C F
Published: January 2020

Restriction endonucleases and agarose gel electrophoresis were used to analyze plasmid pLM2001, which is required for lactose metabolism by Streptococcus lactis LM0232. The enzymes XhoI, SstI, BamHI, and KpnI each cleaved the plasmid into two fragments, whereas EcoRI and BglII cleaved the plasmid into seven and five fragments, respectively. Sizing of fragments and multiple digestions allowed construction of a composite restriction map. The KpnI fragments of pLM2001 were cloned into the KpnI cleavage site of the vector plasmid pDB101. A recombinant plasmid (pSH3) obtained from a lactose-fermenting, erythromycin-resistant (Lac+ Eryr) transformant of Streptococcus sanguis Challis was analyzed by enzyme digestion and agarose gel electrophoresis. Plasmid pSH3 contained 7 of the 11 KpnI-HindIII fragments from pLM2001 and 5 of the 7 fragments from pDB101. It was determined that a 23-kilobase (kb) KpnI-generated fragment from pLM2001 had been cloned into pDB101 with deletion of part of the vector plasmid. The recombinant plasmid could be transformed with high frequency into several Lac- strains of S. sanguis, conferring the ability to ferment lactose and erythromycin resistance. The presence of pSH3 allowed a strain deficient in Enzyme IIlac, Factor IIIlac, and phospho-beta-galactosidase of the lactose phosphoenolpyruvate-dependent phosphotransferase system to efficiently ferment lactose. Under conditions designed to maximize curing of plasmid DNA with acriflavin, no Lac- derivatives could be isolated from cells transformed with pSH3. Seven of the 40 Lac+ colonies isolated after 10 transfers in acriflavin were shown to be sensitive to erythromycin and did not appear to harbor plasmid DNA.(ABSTRACT TRUNCATED AT 250 WORDS)
Isolation of Aeromonas spp. from an unchlorinated domestic water supply
Authors: Burke V , Robinson J , Gracey M , Peterson D , Meyer N , Haley V
Published: January 2020

The recovery of Aeromonas spp. from the unchlorinated water supply for a Western Australian city of 21,000 people was monitored at several sampling points during a period of 1 year. Membrane filtration techniques were used to count colonies of Aeromonas spp., coliforms, and Escherichia coli in water sampled before entry to service reservoirs, during storage in service reservoirs, and in distribution systems. Aeromonas spp. were identified by subculture on blood agar with ampicillin, oxidase tests, and the use of Kaper medium and then were tested for production of enterotoxins and hemolysins. During the same period, two-thirds of all fecal specimens sent for microbiological examination were cultured on ampicillin-blood agar for Aeromonas spp. Recovery of Aeromonas spp. from water supplies at distribution points correlated with fecal isolations and continued during autumn and winter. Coliforms and E. coli were found most commonly in late summer to autumn. This pattern differs from the summer peak of Aeromonas isolations both from water and from patients with Aeromonas spp.-associated gastroenteritis in Perth, Western Australia, a city with a chlorinated domestic water supply. Of the Aeromonas strains from water, 61% were enterotoxigenic, and 64% produced hemolysins.
Evaluation of m-T7 agar as a fecal coliform medium
Authors: LeChevallier M W , Jakanoski P E , Camper A K , McFeters G A
Published: January 2020

m-T7 agar, designed to improve recoveries of injured total coliforms, was evaluated for its effectiveness as a fecal coliform medium. The time and temperature of preincubation were found to be crucial to the optimal recovery of fetal coliforms. Isolation rates for fecal coliforms on m-T7 agar from sewage effluents were the highest when plates were preincubated at 37 degrees C for 8 h before transfer to 44.5 degrees C for 12 h. The medium was found to produce consistently higher fecal coliform counts than all the other methods tested. Recoveries were 3.1 times greater than the standard m-FC method and 1.7 times greater than the two-layer enrichment, temperature acclimation procedure. Verification rates for fecal coliforms isolated on m-T7 agar averaged 89.0%, whereas verification rates for m-FC agar averaged only 82.8%. Both media isolated similar fecal coliform populations. The advantages of a single medium, highly effective for the isolation of both total and fecal coliforms, are discussed.
Substrate utilization by Legionella cells after cryopreservation in phosphate buffer
Authors: Weiss E , Westfall H N
Published: January 2020

The objective of this study was to evaluate by relatively simple metabolic tests the usefulness of buffers and energy sources commonly used in Legionella growth media. Legionella pneumophila serogroups 1 to 6, Legionella micdadei, and Legionella bozemanii were grown in an enriched charcoal-yeast extract diphasic medium. The cells were washed thrice, suspended in various buffers (pH 6.9) with 1 or 5 mM MgSO4, and used immediately or after controlled-rate cryopreservation. CO2 produced and C incorporated into the cold trichloracetic acid-insoluble fractions from 14C-labeled substrates were determine. Potassium phosphate buffer (0.02 M) was as satisfactory as organic buffers for glutamate metabolism, but the addition of KCl or NaCl reduced activity. Metabolic activity for glutamate was not lost upon cryopreservation, and cryopreserved cells were used to test the utilization of other single or paired substrates. Rates of activity for serine, glutamate, threonine, and pyruvate, in this descending order, were high, and those for alpha-ketoglutarate, succinate, and gamma-aminobutyrate were low. Although glutamine was not used as rapidly as glutamate, when added to glutamate it was preferentially metabolized, possibly because of more rapid transport. When glutamate and serine were combined, glutamate furnished more C for CO2 and less for incorporation, whereas the reverse was true of serine. In conclusion, glutamate as an energy source may in some cases spare other amino acids for synthesis. alpha-Ketoglutarate, a common constituent of Legionella media, may reduce oxygen toxicity but is probably not a chief energy source.
Survey of sensitivity of twelve yeast genera toward T-2 toxin
Authors: Sukroongreung S , Schappert K T , Khachatourians G G
Published: January 2020

A survey was made to detect the sensitivity of 12 yeast genera to T-2 toxin. Seventy-five yeasts isolated from various sources were tested for their susceptibility to T-2 toxin. The MIC of T-2 for these yeasts varied from 1.0 to greater than 8.0 micrograms/ml. Of the yeasts studied, Kluyveromyces fragilis showed the greatest sensitivity, which ranged between 0.5 and 2.5 micrograms of T-2 toxin per ml of culture medium. The roles of incubation temperature, size of the inoculum, and incubation time on the MICs were determined. The results suggest that in comparison with other yeasts, K. fragilis is very sensitive to T-2 toxin.
Influence of water temperature, salinity, and pH on survival and growth of toxigenic Vibrio cholerae serovar 01 associated with live copepods in laboratory microcosms
Authors: Huq A , West P A , Small E B , Huq M I , Colwell R R
Published: January 2020

The influence of water temperature, salinity, and pH on the multiplication of toxigenic Vibrio cholerae serovar O1 cells and their attachment to live planktonic crustaceans, i.e., copepods, was investigated by using laboratory microcosms. By increasing water temperatures up to 30 degrees C, a pronounced effect on the multiplication of V. cholerae was demonstrated, as was attachment of the cells to live copepods. These were measured by culturable counts on agar plates and direct observation by scanning electron microscopy, respectively. Of the three salinities examined (5, 10, and 15%), maximum growth of V. cholerae and attachment to copepods occurred at 15%. An alkaline pH (8.5) was optimal both for attachment and multiplication of V. cholerae, as compared with pH 6.5 and 7.5. It is concluded that conditions affecting attachment of V. cholerae serovar O1 to live copepods observed under laboratory conditions may also occur in the natural estuarine environment and, thereby, are significant in the epidemiology of cholera.
R-plasmid transfer in Salmonella spp. isolated from wastewater and sewage-contaminated surface waters
Authors: Alcaide E , Garay E
Published: January 2020

A total of 865 Salmonella isolates from wastewaters and sewage-contaminated natural waters were tested for antimicrobial resistance by using NR10 medium and incubation at 43 degrees C. Of the strains, 12.7% were resistant to one or more of the compounds tested, and 30% transferred resistance to an Escherichia coli recipient. The highest minimal inhibitory concentrations were ca. 1,000 micrograms/ml. Transfer frequencies ranged from 10(-3) to 10(-7).
Inhibitory effects of titanium (III) citrate on enumeration of bacteria from rumen contents
Authors: Wachenheim D E , Hespell R B
Published: January 2020

Titanium citrate (TC) or L-cysteine-sodium sulfide was added as a reducing agent to buffers and agar media used for enumeration of bacteria from rumen contents of high-forage-fed steers. Approximately equal colony counts were found on TC and L-cysteine-sodium sulfide-reduced media with rumen contents taken 8 h postfeeding, when active bacterial growth was occurring. The colony counts on TC medium were only 56% of those with L-cysteine-sodium sulfide medium with rumen contents taken 1 h prefeeding when bacterial growth was minimal. When colonies from L-cysteine-sodium sulfide medium were transferred to TC medium and vice versa, almost all colonies grew. The data indicate that TC can be inhibitory to bacteria upon their initial isolation from natural habitats, particularly when growth rates are low in these habitats.
Methanogens and anaerobes in a colon segment isolated from the normal fecal stream
Authors: Miller T L , Weaver G A , Wolin M J
Published: January 2020

Methanogens were in the isolated sigmoid colon but not in the colostomy bag of a woman with a left hemicolectomy with end colostomy and mucous fistula. The predominant methanogen was Methanobrevibacter smithii. An anaerobic bacterial community supported by nondietary substrates was present in the isolated sigmoid colon.
Purification of Giardia muris cysts by velocity sedimentation
Authors: Sauch J F
Published: January 2020

Giardia muris cysts were separated from fecal contaminants in primary isolates by unit gravity velocity sedimentation. Crude isolates obtained by centrifugation over 1.0 M sucrose were overlaid onto a Percoll density gradient, 1.01 to 1.03 g/ml. G. muris cysts were well separated from faster-sedimenting fecal debris and slower-sedimenting Spironucleus muris and bacteria in 1.5 h.
Effects of short-term cold storage on recovery of proteases from extracellular products of Aeromonas hydrophila
Authors: Amborski R L , Borall R , Thune R L
Published: January 2020

Three protease-containing fractions were recovered by gel filtration from concentrated crude extracellular products produced by Aeromonas hydrophila grown in a defined medium. The recovery of a heat-stable protease was differentially prevented when the crude preparation was stored for 48 h at -20 degrees C but was unaffected by storage of the crude preparation at either 4 or -70 degrees C. Once fractionated, the heat-stable protease appeared to be unaffected by subsequent storage at 4, -20, or -70 degrees C.
Enhancing Soybean Rhizosphere Colonization by
Rhizobium japonicum
Authors: Hossain A. K. Maqbul , Alexander Martin
Published: January 2020

A study was conducted to seek means to increase the colonization of the rhizosphere of soybeans (
Glycine max
L. Merrill) by
Rhizobium japonicum.
For this purpose, a strain of
R. japonicum
that was resistant to benomyl, streptomycin, and erythromycin was used. The numbers of
R. japonicum
rose quickly in the first 2 days after soybean seeds were planted in soil and then rapidly fell. The decline was slower if the seeds were coated with benomyl. This fungicide reduced the numbers of bacteria and protozoa in the rhizosphere, but the effect became less or disappeared as the plants grew. In sterile soil inoculated with
R. japonicum
and a mixture of microorganisms, the numbers of
R. japonicum
were usually lower if protozoa were present than if they were absent. Nodulation and plant yield were increased by the addition of benomyl to soybean seeds sown in sterile soil inoculated with
R. japonicum
and a mixture of microorganisms. The addition of streptomycin and erythromycin to soil stimulated the growth of
R. japonicum
but inhibited other bacteria in the presence or absence of soybeans. The data indicate that colonization can be increased by the use of antimicrobial agents and
R. japonicum
strains resistant to those inhibitors.
Rumen Fungi and Forage Fiber Degradation
Authors: Windham W. R. , Akin Danny E.
Published: January 2020

The role of anaerobic rumen fungi in in vitro forage fiber degradation was determined in a two forage × two inoculum source × five treatment factorial design. Forages used as substrates for rumen microorganisms were Coastal bermuda grass and alfalfa; inoculum sources were rumen fluid samples from a steer fed Coastal bermuda grass hay or alfalfa hay; treatments were whole rumen fluid (WRF), WRF plus streptomycin (0.2 mg/ml of rumen fluid) and penicillin (1.25 mg/ml of fluid), WRF plus cycloheximide (0.5 mg/ml of fluid), WRF plus streptomycin, penicillin, and cycloheximide, and McDougall buffer. Populations of fungi as shown by sporangial development were greater on bermuda grass leaves than on alfalfa leaflets regardless of inoculum source. However, endogenous fungal populations were greater from the alfalfa hay inoculum. Cycloheximide inhibited the fungi, whereas streptomycin and penicillin, which inhibit bacterial populations, resulted in an increase in numbers of sporangia in the alfalfa inoculum, suggesting an interaction between bacteria and fungi. Bacteria (i.e., WRF plus cycloheximide) were equal to the total population in degrading dry matter, neutral-detergent fiber (NDF), acid-detergent fiber (ADF), and cellulose for both inocula and both forages. Degradation of dry matter, NDF, ADF, and cellulose by anaerobic fungi (i.e., WRF plus streptomycin and penicillin) was less than that due to the total population or bacteria alone. However, NDF, ADF, and cellulose digestion was 1.3, 2.4, and 7.9 percentage units higher, respectively, for bermuda grass substrate with the alfalfa versus bermuda grass inoculum, suggesting a slight benefit by rumen fungi. No substantial loss of lignin (72% H
2
SO
4
method) occurred due to fungal degradation. The most active fiber-digesting population in the rumen was the bacteria, even when streptomycin and penicillin treatment resulted in an increase in rumen fungi over untreated WRF. The development of large numbers of sporangia on fiber may not indicate a substantial role as digesters of forage.
Effects of airflow rates and operator activity on containment of bacterial aerosols in a class II safety cabinet
Authors: Macher J M , First M W
Published: January 2020

Biological safety cabinets are frequently relied upon to provide sterile work environments in which hazardous microorganisms can be safely handled. Verification of correct airstream velocities does not, by itself, ensure that adequate protection will be achieved under all users. Instead, the concentration of microorganisms in a cabinet operator's breathing zone must be measured during typical cabinet use conditions to determine whether the exposure is below acceptable limits. In this study, cabinet operator exposures were measured with a personal air sampler. Bacterial spores were released inside a cabinet as a uniform challenge aerosol, and the number of escaping spores was measured for several cabinet arrangements during a number of typical operations. The following were studied to determine their effects on aerosol containment: inflow air velocity, size of access opening, type of operator movements, location of operator's hands, and pace of activity. Other experiments examined differences in aerosol containment for eight typical microbiology operations when performed by six operators who covered a range of body heights and volumes.
Characterization of a Small RNA-Containing Virus in Field-Collected Larvae of the Tussock Moth,
Lymantria ninayi
, from Papua New Guinea
Authors: Pullin Julian S. K. , Black Fraser , King Linda A. , Entwistle Philip F. , Moore Norman. F.
Published: January 2020

Field-collected larvae of the tussock moth,
Lymantria ninayi
, a major pest of exotic pines in Papua New Guinea, were found to contain a small RNA-containing virus with a diameter of 29 nm and a buoyant density of 1.32 g/ml. The RNA was single stranded, had a molecular weight of 2.8 × 10
6
, and was polyadenylated. Virion RNA stimulated an in vitro translation system, and high-molecular-weight proteins were produced. Purified virions contained four structural proteins with molecular weights of 43,000, 38,000, 33,000, and 32,000. The virus reacted positively with antisera raised against a strain of
Drosophila
C virus. The properties of this virus indicate that it should be placed in the family Picornaviridae.
Identification of Campylobacter coli isolates from animals and humans by bacterial restriction endonuclease DNA analysis
Authors: Kakoyiannis C K , Winter P J , Marshall R B
Published: January 2020

Ninety-nine Campylobacter coli isolates were examined by bacterial restriction endonuclease DNA analysis (BRENDA) with HindIII. Isolates from poultry from the same environment had identical patterns, patterns of isolates carried by suckling piglets were generally the same as those of isolates recovered from their dams, and one human patient yielded the same BRENDA type when sampled 6 weeks later. The 14 human isolates examined produced 11 distinct BRENDA types. Forty-three C. coli isolates from pigs were represented by 20 BRENDA types. Ten C. coli isolates from the feces of gulls yielded five different BRENDA types. Thirty-two C. coli isolates from live chickens and processed chicken yielded five different BRENDA types. Three human isolates had identical DNA patterns; two were from brothers living in the same house, and the third was from a human with no apparent relationship to the brothers. Another human isolate was identical to a poultry isolate. None of the pig strains had DNA patterns resembling those of human strains, nor were the DNA patterns like those of any strains recovered from poultry or gulls. Four C. coli isolates were subcultured onto agar 23 times over a period of 45 days, and their BRENDA patterns were preserved. BRENDA shows great promise for use in epidemiological studies of C. coli.
Effects of Aluminum and Manganese on the Growth of Ectomycorrhizal Fungi
Authors: Thompson Gail W. , Medve Richard J.
Published: January 2020

Cenococcum graniforme, Suillus luteus, Thelephora terrestris
, and three isolates of
Pisolithus tinctorius
were cultured on modified Melin-Norkrans medium at pH 3.4 and adjusted to 0 to 500 ppm (0 to 500 μg/ml) of aluminum or manganese sulfate. Except for
T. terrestris
, which was intolerant of aluminum at 150 and 250 to 500 ppm, and
P. tinctorius
isolate 250, which was intolerant of aluminum at 450 ppm, all fungi showed some growth at all concentrations of aluminum.
S. luteus
was the most tolerant to aluminum. Manganese was less fungitoxic than aluminum, with all fungi showing at least 65% growth at 500 ppm as compared with the control.
C. graniforme
was not inhibited at any concentration of manganese, and
S. luteus
was only affected at 500 ppm.
P. tinctorius
isolate 230 showed no significant variation in growth when subjected to various concentrations of three forms of manganese salts. Significant differences in growth were detected in response to three aluminum salts, but no detectable pattern was apparent. Genotypic responses to aluminum and manganese were evident for
P. tinctorius
. Isolates 210 and 230 were more tolerant to manganese than was isolate 250. Aluminum tolerance was in the order of isolate 230 > 210 > 250. Results of in vitro studies concerning tolerance responses of ectomycorrhizal fungi to aluminum and manganese were not consistent with field observations of the successional sequence of these fungi on acid coal spoils.
Effects of microbial community interactions on transformation rates of xenobiotic chemicals
Authors: Lewis D L , Hodson R E , Freeman L F
Published: January 2020

The effects of culture filtrates, mixed populations, and common microbial exudates on bacterial transformations of three agricultural and industrial chemicals were investigated. Test chemicals included methyl parathion, diethyl phthalate, and 2,4-dichlorophenoxyacetic acid butoxyethyl ester. The presence of various cultures, filtrates, or exudates of algae, fungi, or other bacteria either stimulated or inhibited bacterial transformation rates. Inhibition resulted from treatments that lowered the pH, and stimulation resulted from an increase in cell biomass (based on plate counts) and from a different process whereby rates of transformation per bacterial cell rapidly increased as much as 10-fold.
Septage treatments to reduce the numbers of bacteria and polioviruses
Authors: Stramer S L , Cliver D O
Published: January 2020

Disposal of the pumped contents of septic tanks (septage) represents a possible means of dissemination of enteric pathogens including viruses, since persistence of enteroviruses in septic tank sludge for greater than 100 days has been demonstrated. The risk of exposure to potentially infectious agents can be reduced by disinfecting septages before their disposal. Of the septage disinfectants examined (technical and analytical grade glutaraldehyde, hydrogen peroxide, heat treatments, and a combination of heat and hydrogen peroxide), the treatment including hydrogen peroxide (5 mg, plus 0.33 mg of trichloroacetic acid, per ml of septage) and 55 degrees C killed virtually all the bacteria in septage within 1 h, whereas 55 degrees C alone inactivated inoculated polioviruses within 30 min. Virus was the most sensitive to heat, whereas fecal coliforms appeared to be the most sensitive to all chemical treatments. The responses of fecal streptococci and virus to both grades of glutaraldehyde (each at 1 mg/ml) were similar. Virus was more resistant than either fecal streptococci or total bacteria to low concentrations of hydrogen peroxide (1 to 5 mg/ml); however, virus and fecal streptococci were more labile than total bacteria to the highest peroxide concentration (10 mg/ml) examined. It is possible that the treatment combining heat and hydrogen peroxide was the most effective in reducing the concentrations of all bacteria, because catalase and peroxidases as well as other enzymes were heat inactivated, although catalase seems the most likely cause of damage. However, this most effective treatment does not appear to be practical for on-site use as performed, so further work on septage disinfection is recommended.
Bioconversion of Lithocholic Acid Under Anaerobic Conditions by
Pseudomonas
sp. Strain NCIB 10590
Authors: Owen Robert W. , Bilton Rodney F.
Published: January 2020

The biotransformation of lithocholic acid by
Pseudomonas
sp. strain NCIB 10590 under anaerobic conditions was studied. The major products were identified as androsta-1,4-diene-3,17-dione and 3-oxochol-4-ene-24-oic acid. The minor products included 17β-hydroxyandrost-4-ene-3-one, 17β-hydroxyandrosta-1,4-diene-3-one, 3-oxo-5β-cholan-24-oic acid, 3-oxochola-1,4-diene-24-oic acid, 3-oxopregn-4-ene-20-carboxylic acid, and 3-oxopregna-1,4-diene-20-carboxylic acid. Anaerobiosis increases the number of metabolites produced by
Pseudomonas
sp. NCIB 10590 from lithocholic acid.
Formation and Identification of Interfacial-Active Glycolipids from Resting Microbial Cells
Authors: Li Zu-Yi , Lang Siegmund , Wagner Fritz , Witte Ludger , Wray Victor
Published: January 2020

Resting cells of
Arthrobacter sp.
strain DSM2567 incubated in the presence of various mono-, di-, or trisaccharides biosynthesized different glycolipids. All eight glycolipids, containing the corresponding carbohydrate moiety and one, two, or three α-branched β-hydroxy fatty acids, were produced when mannose, glucose, cellobiose, maltose, and maltotriose were used as carbon sources in a simple phosphate buffer. The structures of the compounds were elucidated by means of
1
H and
13
C nuclear magnetic resonance spectroscopy and by chemical ionization mass spectroscopy. In high-salinity solution, the substances showed different surfactant properties. Cellobiose and maltose monocorynomycolates reduced the interfacial tension from 42 to 1 mN/m at critical micelle concentrations below 20 mg/liter.
Oral toxicity of Bacillus thuringiensis subsp. israelensis to adult mosquitoes
Authors: Klowden M J , Bulla L A
Published: January 2020

The solubilized entomotoxin of Bacillus thuringiensis subsp. israelensis killed adult male and female mosquitoes of several genera and of various physiological states when it was administered orally. Adult mosquito mortality was further influenced when the preparation was contained in sucrose solution. The potential implication for the control of adult mosquitoes is discussed.
Production of Verrucarol
Authors: Jarvis Bruce B. , Yatawara C. S. , Greene Sharon L. , Vrudhula Vivekanada M.
Published: January 2020

Verrucarol was obtained from a simple procedure that involved the hydrolysis of a crude extract of a culture of
Myrothecium verrucaria
ATCC 24571.
Comparison of methods of enumerating coliforms after UV disinfection
Authors: Qualls R G , Chang J C , Ossoff S F , Johnson J D
Published: January 2020

In view of the differences that have been found between the most-probable-number and membrane filtration methods for the recovery of coliforms from chlorinated samples, the survival of total and fecal coliforms in UV-irradiated effluent samples, as tested by the most-probable-number and standard single-step membrane filtration methods, was compared. There were no significant differences in the survival of total and fecal coliforms, as tested by the two methods. In a separate set of experiments comparing total and fecal coliform survival, as tested by the most-probable-number method, only a very small but statistically significant difference of 0.1 log survival units was found. For UV-disinfected wastewater effluents, standard one-step membrane filtration procedures are comparable to standard most-probable-number procedures.
Production of polyhedrin monoclonal antibodies for distinguishing two Orgyia pseudotsugata baculoviruses
Authors: Quant R L , Pearson M N , Rohrmann G F , Beaudreau G S
Published: January 2020

Monoclonal antibodies were produced to polyhedrins from Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) and single-capsid nuclear polyhedrosis virus (OpSNPV). Although the polyhedrins are closely related, antibodies were selected which allowed differentiation between the two viruses. In an indirect enzyme-linked immunosorbent assay, purified OpMNPV and OpSNPV polyhedrins could be detected by specific monoclonal antibodies at concentrations as low as 2 and 5 ng/ml, respectively. The antibodies were also capable of identifying their homologous polyhedrin in extracts of infected insects. These antibodies would be useful for monitoring production of the viral insecticide, TM Biocontrol-1, which by license must contain only OpMNPV, and to confirm that insect mortality after aerial spraying with this insecticide is attributable to OpMNPV infection.
Mixed Continuous Cultures of Polyvinyl Alcohol-Utilizing Symbionts
Pseudomonas putida
VM15A and
Pseudomonas
sp. Strain VM15C
Authors: Shimao Masayuki , Fukuta Ikuo , Kato Nobuo , Sakazawa Chikahiro
Published: January 2020

Stable mixed continuous cultures of
Pseudomonas
sp. strain VM15C and
Pseudomonas putida
VM15A, the former of which produced a polyvinyl alcohol (PVA)-degrading enzyme and the latter of which produced an essential growth factor for PVA utilization by strain VM15C, were established with PVA as the sole source of carbon and energy with chemostat cultivation. A high extent of PVA degradation was achieved at dilution rates of less than 0.030/h. The predominant strain in the cultures was the primary metabolizer of PVA, strain VM15C. The growth supporter, strain VM15A, existed as a minor population, although its population was maintained at an almost constant level throughout a dilution region in which the VM15C population decreased markedly as the dilution rate was raised. A crude growth factor which was prepared from a culture supernatant of strain VM15A and increased the specific growth rate of strain VM15C with PVA in an axenic batch culture was also effective for enhancing the VM15C population and PVA degradation in the mixed continuous culture at a high dilution rate (0.064/h). This indicated that the growth-limiting substrate for strain VM15C in the mixed continuous culture is the growth factor produced by strain VM15A.
Comparison of Assimilatory Organic Nitrogen, Sulfur, and Carbon Sources for Growth of
Methanobacterium
Species
Authors: Bhatnagar L. , Jain M. K. , Aubert J.-P. , Zeikus J. G.
Published: January 2020

Experiments document the ability of two species of autotrophic methanogens to assimilate and utilize organic substrates as the nutrient sulfur or nitrogen source and as a carbon source during growth on H
2
-CO
2
.
Methanobacterium thermoautotrophicum
strain ΔH and the mesophilic species
Methanobacterium
sp. strain Ivanov grew with glutamine as the nitrogen source or cysteine as the sulfur source.
M. thermoautotrophicum
also utilized urea as the nitrogen source and as a carbon precursor for methane and cell synthesis.
Methanobacterium
sp. strain Ivanov grew with methionine as the sulfur source. The growth rate of two different
Methanobacterium
species was lower on an organic N or S source than on ammonium or sulfide.
35
S and
14
C tracer studies demonstrated that amino acid or urea assimilation correlated with time and amount of growth. The rate of [
35
S]cysteine incorporation was similar in strain ΔH (34 nmol h
−1
mg of cells
−1
) and strain Ivanov (23 nmol h
−1
mg of cells
−1
). However, the rate of [
14
C]acetate incorporation was dramatically different (17 versus 208 nmol h
−1
mg of cells
−1
in strains ΔH and Ivanov, respectively). [
14
C]acetate accounted for 1.3 and 21.2% of the total cell carbon synthesized by strains ΔH and Ivanov, respectively. Amino acids and urea were mainly assimilated into the cell protein fraction, but accounted for less than 2.0% of the total cell carbon synthesized. The data suggest that a biochemical-genetic approach to understanding cell carbon synthesis in methanogens is feasible; mutants that are auxotrophic for either acetate, glutamine, cysteine, or methionine are suggested as future targets for genetic studies.
Detection and Quantitation of Methanogens by Enzyme-Linked Immunosorbent Assay
Authors: Archer David B.
Published: January 2020

Antisera to two methanogenic bacteria,
Methanosarcina barkeri
and a
Methanobacterium
sp., were raised in rabbits and used to develop an enzyme-linked immunosorbent assay (ELISA) method. ELISA was shown to be a sensitive technique, detecting as little as 4 ng of methanogen protein. The specificities of the antisera toward other methanogens were evaluated, and it was found that the antisera recognized species of the same genus as the immunizing species, but gave very little cross-reaction with methanogens of different genera. ELISA was used to estimate the growth of methanogens in pure culture. In natural environments and in anaerobic digesters methanogens exist as part of a mixed bacterial community, so the possibility of using ELISA to quantitate methanogens in mixed cultures was examined. The two antisera gave very little reaction in ELISA when non-methanogenic bacteria were used as antigens and ELISA was used to quantitate methanogens in an acetate enrichment culture. I conclude that the ELISA is a useful method for quantitating methanogens in defined mixed cultures, but has limited applicability to more complex systems.
Extracellular metabolism of sucrose in a submerged culture of Claviceps purpurea: formation of monosaccharides and clavine alkaloids
Authors: Kren V , Pazoutová S , Rylko V , Sajdl P , Wurst M , Rehácek Z
Published: January 2020

Transformation of extracellular sucrose during cultivation of Claviceps purpurea led to the formation of mono- and oligosaccharides. Maltose was a suitable substrate for submerged fermentation of alkaloids. Fermentation in a medium with maltose was characterized by an insignificant formation of glucans, intensive sporulation, suspension growth of mycelium, and a higher formation of elymoclavine. Glucose alone yielded low levels of total alkaloids and high glucan formation; on the other hand, glucose promoted the formation of elymoclavine.
Specificity of marine microbial surface interactions
Authors: Imam S H , Bard R F , Tosteson T R
Published: January 2020

The macromolecular surface components involved in intraspecific cell surface interactions of the green microalga Chlorella vulgaris and closely associated bacteria were investigated. The specific surface attachment between this alga and its associated bacteria is mediated by lectin-like macromolecules associated with the surfaces of these cells. The binding activity of these surface polymers was inhibited by specific simple sugars; this suggests the involvement of specific receptor-ligand binding sites on the interactive surfaces. Epifluorescent microscopic evaluation of bacteria-alga interactions in the presence and absence of the macromolecules that mediate these interactions showed that the glycoproteins active in these processes were specific to the microbial sources from which they were obtained. The demonstration and definition of the specificity of these interactions in mixed microbial populations may play an important role in our understanding of the dynamics of marine microbial populations in the sea.
Survival and growth characteristics of Escherichia coli associated with hemorrhagic colitis
Authors: Doyle M P , Schoeni J L
Published: January 2020

Escherichia coli O157:H7 in ground beef was more sensitive to heat than salmonellae, but survived for 9 months at -20 degrees C with little change in number. The organisms grew well in Trypticase soy broth (BBL Microbiology Systems) between 30 and 42 degrees C, with 37 degrees C being optimal for growth. E. coli O157:H7 grew poorly in the temperature range (44 to 45.5 degrees C) generally used for recovery of E. coli from foods.
Plasmid coding for transferable drug resistance in bacteria isolated from cultured rainbow trout
Authors: Toranzo A E , Combarro P , Lemos M L , Barja J L
Published: January 2020

The occurrence of drug resistance and plasmid-mediated transferability was investigated in 170 strains belonging to eight bacterial groups isolated from cultured rainbow trout. It was found that 87.6% of the strains were resistant to at least one drug, with the highest percentages of resistance being detected for ampicillin (54.7%), sulfadiazine (46.5%), nitrofurantoin (38.2%), and chloramphenicol (37.0%). Six enterobacteria, two Vibrio, and one Aeromonas isolate transferred resistance factors to Escherichia coli K-12. The most common transmissible R factor determined resistance to chloramphenicol and sulfadiazine, demonstrating an association between a specific plasmid and the resistance pattern transferred. The presence of chloramphenicol in fish food was detected by bioassay. In general, transfer frequencies were similar in primary and secondary matings, which indicate the potential water-borne dissemination of these R plasmids.
Analysis of sample preparation procedures for enumerating fecal coliforms in coarse southwestern U.S. bottom sediments by the most-probable-number method
Authors: Doyle J D , Tunnicliff B , Kramer R E , Brickler S K
Published: January 2020

The determination of bacterial densities in aquatic sediments generally requires that a dilution-mixing treatment be used before enumeration of organisms by the most-probable-number fermentation tube method can be done. Differential sediment and organism settling rates may, however, influence the distribution of the microbial population after the dilution-mixing process, resulting in biased bacterial density estimates. For standardization of sample preparation procedures, the influence of settling by suspended sediments on the fecal coliform distribution in a mixing vessel was examined. This was accomplished with both inoculated (Escherichia coli) and raw, uninoculated freshwater sediments from Saguaro Lake, Ariz. Both test sediments were coarse (greater than 90% gravel and sand). Coarse sediments are typical of southwestern U.S. lakes. The distribution of fecal coliforms, as determined by the most-probable-number method, was not significantly influenced by sediment settling and remained homogenous over a 16-min postmix period. The technique developed for coarse sediments may be useful for standardizing sample preparation techniques for other sediment types.