bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of methods for quantitative determinations of airborne bacteria and evaluation of total viable counts
Authors: Lundholm I M
Published: January 2020

Three different methods of estimating airborne bacteria were compared. An Anderson sampler, a slit sampler, an impinger, and filter samplers with gelatine filters or membrane filters were tested for collection efficiency. The comparisons were made in laboratory experiments with an aerosol of Staphylococcus epidermidis or Serratia marcescens, in field experiments in two different industries, i.e., cotton mill and sewage plant, and in experiments with skin fragment sampling. Experiments were also performed estimating the total number of viable microorganisms on the airborne particles. The Andersen sampler gave the highest bacterial counts in all environments tested. The slit sampler gave statistically lower counts only in the aerosol experiments and cotton mill experiments, where the size of the majority of the particles carrying visible bacteria was 2 to 6 micrometers or smaller. In the sewage plant and skin fragment experiments, where the particles were mainly 5 micrometers or larger, the difference was not significant. The filters were efficient in sampling in skin fragment experiments only. With the agar impingement method, the total viable cell count showed a rising index value with increasing particle size. A mean of 13 bacteria was found per particle in the cotton mill, a mean of 24 in the sewage plant, and a mean of 147 in skin fragment experiments.
Bubble Contact Angle Method for Evaluating Substratum Interfacial Characteristics and Its Relevance to Bacterial Attachment
Authors: Fletcher Madilyn , Marshall K. C.
Published: January 2020

A bubble contact angle method was used to determine interfacial free-energy characteristics of polystyrene substrata in the presence and absence of potential surface-conditioning proteins (bovine glycoprotein, bovine serum albumin, fatty acid-free bovine serum albumin), a bacterial culture supernatant, and a bacterial exopolymer. Clean petri dish substrata gave a contact angle of 90°, but tissue culture dish substrata were more hydrophilic, giving an angle of 29° or less. Bubble contact angles at the surfaces exposed to the macromolecular solutions varied with the composition and concentration of the solution. Modification by pronase enzymes of the conditioning effect of proteins depended on the nature of both the substratum and the protein, as well as the time of addition of the enzyme relative to the conditioning of the substratum. The effects of dissolved and substratum-adsorbed proteins on the attachment of
Pseudomonas
sp. strain NCMB 2021 to petri dishes and tissue culture dishes were consistent with changes in bubble contact angles (except when proteins were adsorbed to tissue culture dishes before attachment) as were alterations in protein-induced inhibition of bacterial attachment to petri dishes by treatment with pronase. Differences between the attachment of pseudomonads to petri dishes and tissue culture dishes suggested that different mechanisms of adhesion are involved at the surfaces of these two substrata.
Degradation of Coal by the Fungi
Polyporus versicolor
and
Poria monticola
Authors: Cohen Martin S. , Gabriele Peter D.
Published: January 2020

We report that two species of basidiomycete fungi (
Polyporus versicolor
and
Poria monticola
) grow in minimal liquid or solid medium when supplemented with crushed lignite coal. The fungi also grow directly on crushed lignite coal. The growth of both fungi was observed qualitatively as the production and extension of hyphae. No fungal growth occurred in minimal agar medium without coal. The fungi degraded solid lignite coal to a black liquid product which never appeared in cultures unless fungi and coal were present together. Apparently, lignite coal can serve as the principal substrate for the growth of the fungi. Infrared analyses of the liquid products of lignite degradation showed both similarities to and differences from the original lignite.
Nile blue A as a fluorescent stain for poly-beta-hydroxybutyrate
Authors: Ostle A G , Holt J G
Published: January 2020

Poly-beta-hydroxybutyrate granules exhibited a strong orange fluorescence when stained with Nile blue A. Heat-fixed cells were treated with 1% Nile blue A for 10 min and were observed at an excitation wavelength of 460 nm. Glycogen and polyphosphate did not stain. Nile blue A appears to be a more specific stain for poly-beta-hydroxybutyrate than Sudan black B.
Isolation of amoebae from edible mushrooms
Authors: Napolitano J J
Published: January 2020

Isolation of amoebae from the surface and internal tissues of edible mushrooms was investigated. Samples tested over a 3-year period included mushrooms cultivated from six geographic localities. Of 168 mushroom surfaces tested, 161 (96%) yielded amoebae. Of 166 samples of internal stalk and cap tissues tested, only 1 yielded amoebae.
Improved Degradation of Monochlorophenols by a Constructed Strain
Authors: Schwien Uwe , Schmidt Eberhard
Published: January 2020

Pseudomonas
sp. strain B13, a strain able to degrade 3-chlorobenzoate and, after prolonged adaptation (40 days), 4-chlorophenol, could transfer the ability to degrade chlorocatechols to a recipient,
Alcaligenes
sp. strain A7, which is able to grow with benzoate and phenol. Representative transconjugants, such as
Alcaligenes
sp. strain A7-2, were able to utilize all three isomeric chlorophenols; this property was not possessed by the donor or the recipient. The ability to grow readily with 4-chlorophenol may be attributable to a more rapid induction of phenol hydroxylase by
Alcaligenes
sp. strain A7-2 than by
Pseudomonas
sp. strain B13, a property which correlates with the greater level of resistance to chlorophenols shown by the transconjugant.
Biodegradation of Xanthan Gum by
Bacillus
sp
Authors: Cadmus Martin C. , Jackson Linda K. , Burton Kermit A. , Plattner Ronald D. , Slodki Morey E.
Published: January 2020

Strains tentatively identified as
Bacillus
sp. were isolated from sewage sludge and soil and shown to elaborate extracellular enzymes that degrade the extracellular polysaccharide (xanthan gum, polysaccharide B-1459) of
Xanthomonas campestris
NRRL B-1459. Enzyme production by one strain was greatly enhanced when the strain was incubated in a mixed culture. Products of degradation were identified as
d
-glucuronic acid,
d
-mannose, pyruvylated mannose, 6-
O
-acetyl
d
-mannose, and a (1→4)-linked glucan. These products correlate with the known structure of the gum. The complexity of the product mixture indicated that the xanthanase was a mixture of carbohydrases. The xanthanase complexes were similar to one another in temperature stability, pH and temperature optima, degree of substrate degradation, and enzymolysis products. Differences in pH stability, salt tolerance, recoverability, and yields of enzyme were observed.
Role of Aerobic Microbial Populations in Cellulose Digestion by Desert Millipedes
Authors: Taylor Elsa C.
Published: January 2020

I examined the role of aerobic microbial populations in cellulose digestion by two sympatric species of desert millipedes,
Orthoporus ornatus
and
Comanchelus
sp. High numbers of bacteria able to grow on media containing cellulose, carboxymethyl cellulose, or cellobiose as the substrate were found in the alimentary tracts of the millipedes. Enzyme assays indicated that most cellulose and hemicellulose degradation occurred in the midgut, whereas the hindgut was an important site for pectin degradation. Hemicellulase and β-glucosidase in both species and possibly C
x
-cellulase and pectinase in
O. ornatus
were of possible microbial origin. Degradation of [
14
C]cellulose by millipedes whose gut floras were reduced by antibiotic treatment and starvation demonstrated a reduction in
14
CO
2
release and
14
C assimilation and an increase in
14
C excretion over values for controls. It appears that the millipede-bacterium association is mutualistic and makes available to millipedes an otherwise mostly unutilizable substrate. Such an association may be an important pathway for decomposition in desert ecosystems.
Isolation and characterization of Schwanniomyces alluvius amylolytic enzymes
Authors: Wilson J J , Ingledew W M
Published: January 2020

The extracellular amylolytic enzymes of Schwanniomyces alluvius were studied to determine future optimization of this yeast for the production of industrial ethanol from starch. Both alpha-amylase and glucoamylase were isolated and purified. alpha-Amylase had an optimum pH of 6.3 and was stable from pH 4.5 to 7.5. The optimum temperature for the enzyme was 40 degrees C, but it was quickly inactivated at temperatures above 40 degrees C. The Km for soluble starch was 0.364 mg/ml. The molecular weight was calculated to be 61,900 +/- 700. alpha-Amylase was capable of releasing glucose from starch, but not from pullulan. Glucoamylase had an optimum pH of 5.0 and was stable from pH 4.0 to greater than 8.0. The optimum temperature for the enzyme was 50 degrees C, and although less heat sensitive than alpha-amylase, it was quickly inactivated at 60 degrees C. Km values were 12.67 mg/ml for soluble starch and 0.72 mM for maltose. The molecular weight was calculated to be 155,000 +/- 3,000. Glucoamylase released only glucose from both soluble starch and pullulan. S. alluvius is one of the very few yeasts to possess both alpha-amylase and glucoamylase as well as some fermentative capacity to produce ethanol.
Dilution of Liquid
Rhizobium
Cultures To Increase Production Capacity of Inoculant Plants
Authors: Somasegaran Padmanabhan , Halliday Jake
Published: January 2020

Experiments were undertaken to test whether peat-based legume seed inoculants, which are prepared with liquid cultures that have been deliberately diluted, can attain and sustain acceptable numbers of viable rhizobia. Liquid cultures of
Rhizobium japonicum
and
Rhizobium phaseoli
were diluted to give 10
8
, 10
7
, or 10
6
cells per ml, using either deionized water, quarter-strength yeast-mannitol broth, yeast-sucrose broth, or yeast-water. The variously diluted cultures were incorporated into gamma-irradiated peat, and the numbers of viable rhizobia were determined at intervals. In all of the inoculant formulations, the numbers of rhizobia reached similarly high ceiling values by 1 week after incorporation, irrespective not only of the number of cells added initially but also of the nature of the diluent. During week 1 of growth, similar multiplication patterns of the diluted liquid cultures were observed in two different peats. Numbers of rhizobia surviving in the various inoculant formulations were not markedly different after 6 months of storage at 28°C. The method of inoculant preparation did not affect the nitrogen fixation effectiveness of the
Rhizobium
strains.
Metabiotic effect of Bacillus licheniformis on Clostridium botulinum: implications for home-canned tomatoes
Authors: Montville T J
Published: January 2020

The metabiotic effect of Bacillus licheniformis on Clostridium botulinum was examined. B. licheniformis elevated the pH of a model system with an initial pH of 4.4 so that C. botulinum grew and produced toxin. Toxin production was observed when spores from both species were coinoculated at levels as low as 10 spores per ml. When pint jars of tomatoes were used, canner size contributed to a 10,000-fold difference in the lethality of a boiling water bath process on B. licheniformis spores. Botulinal toxin was not detected in pH-elevated jars of tomatoes containing C. botulinum spores.
Effect of sunlight on enumeration of indicator bacteria under field conditions
Authors: Fujioka R S , Narikawa O T
Published: January 2020

The effect of sunlight on the enumeration of fecal coliform (FC) and fecal streptococcal (FS) bacteria when water samples are collected in containers and brought back to the laboratory for analysis or when the water samples are filtered through membranes on site was determined. FC and FS in raw sewage stored in clear glass or translucent polyethylene containers were resistant to the effects of sunlight. However, under the same conditions of storage and exposure to sunlight, 90% of FC and FS in sewage diluted 1:100 in seawater were inactivated within 13 to 32 min. When sewage was similarly diluted in stream water and exposed to sunlight, 90% of FC were inactivated after 28 to 38 min, whereas 90% of FS were not inactivated even after a 2-h exposure to sunlight. Other experiments showed that 90 to 99% of FC and FS retained on membranes were inactivated when these membranes were exposed to sunlight for 10 to 15 min. FS were inherently more resistant to sunlight inactivation than were FC. Finally, evidence was obtained to show that sunlight initially stresses the bacteria but eventually causes cell death.
Activity and growth of microbial populations in pressurized deep-sea sediment and animal gut samples
Authors: Tabor P S , Deming J W , Ohwada K , Colwell R R
Published: January 2020

Benthic animals and sediment samples were collected at deep-sea stations in the northwest (3,600-m depth) and southeast (4,300- and 5200-m depths) Atlantic Ocean. Utilization rates of [14C]glutamate (0.67 to 0.74 nmol) in sediment suspensions incubated at in situ temperatures and pressures (3 to 5 degrees C and 360, 430, or 520 atmospheres) were relatively slow, ranging from 0.09 to 0.39 nmol g-1 day-1, whereas rates for pressurized samples of gut suspensions varied widely, ranging from no detectable activity to a rapid rate of 986 nmol g-1 day-1. Gut flora from a holothurian specimen and a fish demonstrated rapid, barophilic substrate utilization, based on relative rates calculated for pressurized samples and samples held at 1 atm (101.325 kPa). Substrate utilization by microbial populations in several sediment samples was not inhibited by in situ pressure. Deep-sea pressures did not restrict growth, measured as doubling time, of culturable bacteria present in a northwest Atlantic sediment sample and in a gut suspension prepared from an abyssal scavenging amphipod. From the results of this study, it was concluded that microbial populations in benthic environments can demonstrate significant metabolic activity under deep-ocean conditions of temperature and pressure. Furthermore, rates of microbial activity in the guts of benthic macrofauna are potentially more rapid than in surrounding deep-sea sediments.
Diluent composition for use of API 20E in characterizing marine and estuarine bacteria
Authors: MacDonell M T , Singleton F L , Hood M A
Published: January 2020

Nine chemically defined inoculation diluents, with compositions ranging from 0.85% NaCl to 35% marine salts, were used to evaluate the influence of diluent composition on the biochemical profiles of 30 marine and estuarine bacterial strains, including species of Vibrio, Aeromonas, Allomonas, and Photobacterium. Results demonstrated that a 20% marine salts diluent enabled the characterization of halophilic strains normally nonreactive by the API 20E system. Furthermore, the use of 20% marine salts showed that certain environmental isolates, identifiable as Vibrio parahaemolyticus by the recommended clinical inoculation procedure, were Vibrio vulnificus. An analysis of the profiles provided by the nine diluents indicates that the API 20E system, modified by the use of a diluent composed of 20% marine salts and incubated at 22 degrees C, can provide a reliable tool for the rapid characterization of marine and estuarine bacterial isolates.
Histamine-producing bacteria in decomposing skipjack tuna (Katsuwonus pelamis)
Authors: Yoshinaga D H , Frank H A
Published: January 2020

Spoilage in skipjack tuna (Katsuwonus pelamis) was studied under controlled conditions by incubating whole, fresh fish in seawater at 38 degrees C, the optimum temperature for histamine formation. Bacterial isolates were obtained from the loin tissue of a decomposing tuna containing 134 mg of histamine per 100 g and a total anaerobic count of 3.5 x 10(5)/g after incubation for 24 h. Over 92% of the 134 isolates obtained were facultatively or obligately anaerobic bacteria. Eighteen isolates produced histamine in culture media containing histidine, and these were identified as Clostridium perfringens, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, and Vibrio alginolyticus. Histidine decarboxylase activity of several isolates was measured in a tuna broth medium and with resting cells suspended in a buffered histidine solution.
Widespread Distribution of Ability to Oxidize Manganese Among Freshwater Bacteria
Authors: Gregory Eileen , Staley James T.
Published: January 2020

Manganese-oxidizing heterotrophic bacteria were found to comprise a significant proportion of the bacterial community of Lake Washington (Seattle, Wash.) and Lake Virginia (Winter Park, Fla.). Identification of these freshwater bacteria showed that members of a variety of genera are capable of oxidizing manganese. Isolates maintained in the laboratory spontaneously lost the ability to oxidize manganese. A direct correlation was found between the presence of plasmid DNA and the ability of the organism to oxidize manganese.
Detection of glucose oxidation products in chilled fresh beef undergoing spoilage
Authors: Farber J M , Idziak E S
Published: January 2020

The fate of nutrients during storage of longissimus dorsi muscle at 4 degrees C was examined. Glucose concentrations in meat were shown to decrease concomitantly with an approximately fourfold increase in the activity of glucose dehydrogenase. Gluconate concentrations in meat were determined by an enzyme assay and shown to increase from 2.1 to 40.6 microgram/g upon storage of the meat from day 0 to day 6. At day 12, gluconate concentrations had decreased to 5.8 microgram/g. Dark firm dry meat, which contains little or no glucose, did not exhibit the same rise and fall in gluconate concentration. Thin-layer chromatographic analysis confirmed the presence of 2-ketogluconate in 6- and 12-day-old longissimus dorsi muscle that had been stored at 4 degrees C. Gluconate concentrations in irradiated sterile meat inoculated with Pseudomonas fluorescens increased from 4.2 to 77.8 microgram/g during the first 6 days of storage at 4 degrees C. Therefore, glucose in meat stored at 4 degrees C appeared to be converted to gluconate, 2-ketogluconate, or both extracellularly by one of the main meat spoilage organisms, most likely the pseudomonads.
Microbiological quality of macaroni and noodle products obtained at retail markets
Authors: Swartzentruber A , Payne W L , Wentz B A , Barnard R J , Read R B
Published: January 2020

The microbiological quality of macaroni and noodle products was determined by a statistically based national survey at the retail level. Geometric means of aerobic plate counts for macaroni and noodle products were 520 and 1,400 per g, respectively. Means for yeast and mold counts were 72 per g for macaroni and 100 per g for noodles. Means for counts of coliforms and Staphylococcus aureus were less than 3 per g for both products. Escherichia coli was not found in macaroni but was present in 0.5% of the noodle samples and ranged from 3 to 93 per g.
Kinetics of Formate Metabolism in
Methanobacterium formicicum
and
Methanospirillum hungatei
Authors: Schauer Neil L. , Brown David P. , Ferry James G.
Published: January 2020

The kinetics of formate metabolism in
Methanobacterium formicicum
and
Methanospirillum hungatei
were studied with log-phase formate-grown cultures. The progress of formate degradation was followed by the formyltetrahydrofolate synthetase assay for formate and fitted to the integrated form of the Michaelis-Menten equation. The
K

m

and
V

max

values for
Methanobacterium formicicum
were 0.58 mM formate and 0.037 mol of formate h
−1
g
−1
(dry weight), respectively. The lowest concentration of formate metabolized by
Methanobacterium formicicum
was 26 μM. The
K

m

and
V

max

values for
Methanospirillum hungatei
were 0.22 mM and 0.044 mol of formate h
−1
g
−1
(dry weight), respectively. The lowest concentration of formate metabolized by
Methanospirillum hungatei
was 15 μM. The apparent
K

m

for formate by formate dehydrogenase in cell-free extracts of
Methanospirillum hungatei
was 0.11 mM. The
K

m

for H
2
uptake by cultures of
Methanobacterium formicicum
was 6 μM dissolved H
2
. Formate and H
2
were equivalent electron donors for methanogenesis when both substrates were above saturation; however, H
2
uptake was severely depressed when formate was above saturation and the dissolved H
2
was below 6 μM. Formate-grown cultures of
Methanobacterium formicicum
that were substrate limited for 57 h showed an immediate increase in growth and methanogenesis when formate was added to above saturation.
Proteolytic activity of rumen microorganisms and effects of proteinase inhibitors
Authors: Brock F M , Forsberg C W , Buchanan-Smith J G
Published: January 2020

Proteolytic activity of the bovine rumen microflora was studied with azocasein as the substrate. Approximately 25% of the proteolytic activity of rumen contents was recovered in the strained rumen fluid fraction, and the balance of the activity was associated with the particulate fraction. The proportion of proteinase activity associated with particulate material decreased when the quantity of particulate material in rumen contents was reduced. The specific activity of the proteinase from the bacterial fraction was 6 to 10 times higher than that from the protozoal fraction. Proteinase inhibitors of synthetic, plant, and microbial origin were tested on proteolytic activity of the separated bacteria. Synthetic proteinase inhibitors that caused significant inhibition of proteolysis included phenylmethylsulfonyl fluoride, N-tosyl-1-lysine chloromethyl ketone, N-tosylphenylalanine chloromethyl ketone, EDTA, cysteine, dithiothreitol, iodoacetate, and Merthiolate. Plant proteinase inhibitors that had an inhibitory effect included soybean trypsin inhibitors types I-S and II-S and the lima bean trypsin inhibitor. Proteinase inhibitors of microbial origin that showed an inhibitory effect included antipain, leupeptin, and chymostatin; phosphoramidon and pepstatin had little effect. We tentatively concluded that rumen bacteria possess, primarily, serine, cysteine, and metalloproteinases.
Isolation of fungi from bats of the Amazon basin
Authors: Mok W Y , Luizão R C , Barreto da Silva M do S
Published: January 2020

A total of 2,886 bats captured in the Amazon Basin of Brazil were processed for the isolation of fungi. From the livers, spleens, and lungs of 155 bats (5.4%), 186 fungal isolates of the genera Candida (123 isolates), Trichosporon (26 isolates), Torulopsis (25 isolates), Kluyveromyces (11 isolates), and Geotrichum (1 isolate) were recovered. Seven known pathogenic species were present: Candida parapsilosis, C. guilliermondii, C. albicans, C. stellatoidea, C. pseudotropicalis, Trichosporon beigelii, and Torulopsis glabrata. Twenty-three culture-positive bats showed identical fungal colonization in multiple organs or mixed colonization in a single organ. The fungal isolation rates for individual bat species varied from 1 fungus per 87 bats to 3 fungi per 13 bats, and the mycoflora diversity for members of an individual fungus-bearing bat species varied from 16 fungi per 40 bats to 7 fungi per 6 bats. Of the 38 fungal species isolated, 36 had not been previously described as in vivo bat isolates. Of the 27 culture-positive bat species, 21 had not been previously described as mammalian hosts for medically or nonmedically important fungi.
Involvement of plasmids in total degradation of chlorinated biphenyls
Authors: Furukawa K , Chakrabarty A M
Published: January 2020

Acinetobacter sp. strain P6 has previously been reported to utilize biphenyl (BP) and chlorinated BPs, with accumulation of corresponding chlorobenzoic acids. Arthrobacter sp. strain M5 was isolated as a contaminant in the culture of Acinetobacter sp. strain P6 growing on 4-chlorobiphenyl and showed properties similar to P6 in the degradation of chlorinated BPs. Both strains harbored an identical plasmid of 53.7 megadaltons. These strains spontaneously lost the ability to utilize BP and 4-chlorobiphenyl with high frequency (4 to 8%) after overnight growth in nutrient broth. The BP- derivatives could not regain the BP-assimilating ability (reversion frequency, less than 10(-9) per cell per generation) but retained the plasmid with small, detectable deletions. BP+ P6 cells grown on BP or benzoate oxidized BP and 2,3-dihydroxybiphenyl and produced meta cleavage compounds from the latter compound (lambda max, 434 nm) and also from catechol (lambda max, 375 nm) through the meta pathway. On the other hand, benzoate-grown BP- segregants totally lost the BP-metabolizing activities and oxidized catechol through the ortho pathway. A combined culture of the chlorinated BP-dissimilating P6 or M5 strain (harboring the putative 53.7-megadalton plasmid specifying conversion of chlorobiphenyls to chlorobenzoic acids) and genetically constructed mono- or dichlorobenzoate-utilizing pseudomonads (harboring plasmids encoding complete utilization of mono- or dichlorobenzoates) allowed greater than 98% utilization of mono- and dichlorobiphenyls, with the liberation of equivalent amounts of chloride ions.
Vibrio vulnificus biogroup 2: new biogroup pathogenic for eels
Authors: Tison D L , Nishibuchi M , Greenwood J D , Seidler R J
Published: January 2020

Clinical and nonclinical isolates of the lactose-positive Vibrio vulnificus were compared with Vibrio strains isolated from lesions on eels (Anguilla japonica) cultured commercially in Japan. Strains were compared phenotypically and antigenically, for pathogenicity to mice and eels, and for genetic relatedness. The strains isolated from diseased eels differed phenotypically from the original species description of V. vulnificus in that they were negative for indole production, ornithine decarboxylase activity, growth at 42 degrees C, and acid production from mannitol and sorbitol. No relationship between the surface antigens of V. vulnificus strains from environmental and clinical sources and the strains from diseased eels was observed. Typical V. vulnificus strains and the eel isolates were pathogenic to mice; however, only those strains originally isolated from diseased eels were found to be pathogenic to eels. Results of DNA-DNA competition experiments revealed that there was greater than 90% relative reassociation between clinical and nonclinical V. vulnificus and strains from diseased eels. Based on the results of the DNA-DNA competition experiments, we conclude that the strains isolated from diseased eels were V. vulnificus; however, the differences in phenotypic characteristics and eel pathogenicity indicated that these strains represent a different biogroup. Therefore, we propose that strains phenotypically similar to the type strain of the species (ATCC 27562) be classified as V. vulnificus biogroup 1 and the strains phenotypically similar to those isolated from diseased eels be classified as V. vulnificus biogroup 2 represented by the reference strain ATCC 33148.
Biomagnification of Aroclor 1242 in Decomposing
Spartina
Litter
Authors: Marinucci Andrew C. , Bartha R.
Published: January 2020

The accumulation of a polychlorinated biphenyl (PCB) mixture (Aroclor 1242) in the process of detritus formation by a shredded marshgrass (
Spartina alterniflora
) under aerobic conditions was monitored in percolators for 4 months at 20°C. Dissolved PCB in the influent solution was 14 to 16 μg/liter. Parameters monitored in addition to PCB accumulation were CO
2
evolution, NH
4
+
uptake, NO
3
−
production, and total organic nitrogen and carbon in the effluent. An NaN
3−
poisoned control served to assess nonbiological PCB absorption. Up to 90% of the PCB dissolved in the influent water was removed by the biologically active detritus. Biomagnification resulted in three to four times higher PCB concentrations in the active detritus than in the abiotic control. Evolution of CO
2
was slightly depressed by PCB, but the overall quality (C:N ratio) of the detritus was not affected. The results indicate that bioaccumulation of PCB in detritus is an important means of entry for this pollutant into estuarine food webs.
Metabolism of 7-methylbenz[a]anthracene and 7-hydroxymethylbenz[a]anthracene by Cunninghamella elegans
Authors: Cerniglia C E , Fu P P , Yang S K
Published: January 2020

The fungal metabolism of 7-methylbenz[a]anthracene (7-MBA) and 7-hydroxymethylbenz[a]anthracene (7-OHMBA) was studied. 7-MBA was metabolized by Cunninghamella elegans to form 7-OHMBA-trans-8,9-dihydrodiol and 7-OHMBA-trans-3,4-dihydrodiol as the predominant metabolites. Other metabolites were identified as 7-OHMBA, 7-MBA-trans-8,9-dihydrodiol and 7-MBA-trans-3,4-dihydrodiol, and 7-MBA-8,9,10,11-tetraol. Incubation of 7-OHMBA with C. elegans cells indicated that 7-OHMBA-trans-8,9-dihydrodiol and 7-OHMBA-trans-3,4-dihydrodiol were major metabolites. The metabolism of 7-MBA by rat liver microsomes from 3-methylcholanthrene-treated rats showed that the metabolites were qualitatively similar to those formed by C. elegans, except additional dihydrodiol metabolites were formed at the 5,6 and 10,11 positions. The metabolites formed were isolated by high-performance liquid chromatography and identified by comparing their chromatographic, UV-visible absorption and mass spectral properties with those of reference compounds.
Kaolin Powder as a Fungal Carrier
Authors: Bhattacharyya S. K. , Basu M. K.
Published: January 2020

Kaolin powder may be used to carry and preserve an
Aspergillus
sp. for at least 90 days without contamination and with retention of its activity in softening and upgrading barky jute.
Isolation of Marine Bacteria Capable of Producing Specific Lyases for Alginate Degradation
Authors: Doubet R. Scott , Quatrano Ralph S.
Published: January 2020

Alginate lyases (EC 4.2.2.3) were isolated from cultures of several marine bacterial isolates. The lyases were induced by native alginate and had activity toward both the mannuronic acid and the guluronic acid blocks of the alginate polymer. The guluronic acid-specific lyase was recovered from the medium, whereas the mannuronic acid-specific lyase was retained with the bacteria.
Thermophilic biotransformations of 2,4,6-trinitrotoluene under simulated composting conditions
Authors: Kaplan D L , Kaplan A M
Published: January 2020

The biotransformations of 14C-labeled 2,4,6-trinitrotoluene by thermophilic microorganisms in a compost system were determined. The reduction products identified in solvent extracts were similar to those identified in mesophilic systems. A significant percentage of the 14C-labeled products were bound to humus fractions.
Aerobic and anaerobic microorganisms in tubercles of the Columbus, Ohio, water distribution system
Authors: Tuovinen O H , Hsu J C
Published: January 2020

Aerobic and anaerobic microorganisms were enumerated in tubercles collected from sections of the water distribution pipeline in the Columbus, Ohio, metropolitan area. Coliform bacteria were not detected in the tubercles examined. Sulfate-reducing bacteria were detected in 80% of the samples. Nitrate-reducing heterotrophs were present in all samples. The results, including plate counts of aerobic heterotrophs, indicated variation in bacterial densities depending on the tubercle sample and fraction examined. The associations among the viable counts obtained by the different culture methods were analyzed statistically, using three methods (Pearson, Spearman, and Kendall).
Underestimation of total-coliform counts by the membrane filter verification procedure
Authors: Standridge J H , Delfino J J
Published: January 2020

Coliforms, primarily Citrobacter freundii, gave negative verification results in the total-coliform membrane filtration test. The organisms produced gas from lactose in brilliant green bile broth but not in lauryl tryptose broth. The discrepancy was related to the peptone sources used in the media.
Enhanced Production of 2,3-Butanediol by
Klebsiella pneumoniae
Grown on High Sugar Concentrations in the Presence of Acetic Acid
Authors: Yu Ernest K. C. , Saddler John N.
Published: January 2020

The bioconversion of sugars present in wood hemicellulose to 2,3-butanediol (hereafter referred to as butanediol) by
Klebsiella pneumoniae
grown on high initial concentrations (up to 10%) of sugars was investigated. Initial fermentation studies with a chemically defined medium suggested that sugar levels in excess of 2% could not be utlized even when a higher inoculum size (5 to 10%) was used. The addition of nutrient supplements, viz., yeast extract, urea, ammonium sulfate, and trace elements resulted in a 10 to 50% increase in butanediol yields, although sugar utilization remained incomplete. The concentration of end products normally found at the termination of fermentation was shown to be noninhibitory to growth and substrate utilization. Acetic acid was inhibitory at concentrations above 1%, although growth and butanediol yield were stimulated in cultures supplemented with lower levels of acetic acid. The efficient utilization of 4% substrate concentrations of
d
-glucose and
d
-xylose was achieved, resulting in butanediol yields of 19.6 and 22.0 g/liter, respectively.
Effect of temperature and salinity on Vibrio (Beneckea) vulnificus occurrence in a Gulf Coast environment
Authors: Kelly M T
Published: January 2020

Vibrio (Beneckea) vulnificus is a recently recognized halophilic organism that may cause serious human infections. Patients infected with V. vulnificus often have a history of exposure to the sea, suggesting that the organism may be a common inhabitant of marine environments. Twenty-one inshore sites around Galveston Island in the Gulf of Mexico were cultured for V. vulnificus over a 12-month period. The organism was recovered from all but one of the sites at some time during the study. It was frequently isolated during the summer and fall from environments of relatively low salinity (7 to 16%). V. vulnificus was rarely isolated from any of the sites during the winter months, when water temperatures dropped below 20 degrees C. In vitro growth characteristics of environmental isolates of V. vulnificus demonstrated salinity optima of 1.0 to 2.0% NaCl and a temperature optimum of 37 degrees C. These growth characteristics may account for the seasonal and geographical variations in occurrence of the organism. Overall, the results of these studies indicate that V. vulnificus is commonly found in Gulf Coast environments and that the occurrence of the organism is favored by warm temperatures and relatively low salinity.
Susceptibility of fecal streptococci of poultry origin to nine growth-promoting agents
Authors: Dutta G N , Devriese L A
Published: January 2020

The minimal inhibitory concentrations of nine growth-promoting agents were determined by an agar-dilution method against 66 bile-tolerant streptococcal (8 Streptococcus faecalis, 23 Streptococcus faecalis subsp. liquefaciens, 15 Streptococcus faecium, and 20 carboxyphilic streptococci) strains isolated from the ceca of 52 chickens on 19 farms. Avoparcin was equally active on all groups. The natural susceptibilities against the other substances differed among the groups studied. Bacitracin and virginiamycin were more active on S. faecium and S. faecalis than on S. faecalis subsp. liquefaciens; lincomycin and the macrolide antibiotics were more active on S. faecium than on the other groups; and flavomycin was active on all groups except S. faecium. High percentages of acquired resistance were noted in all groups against bacitracin, lincomycin, and the macrolide antibiotics, oleandomycin, spiramycin, and tylosin. Resistance to nitrovin was found only among the S. faecalis and S. faecium groups.
Temperature Adaptations in the Terminal Processes of Anaerobic Decomposition of Yellowstone National Park and Icelandic Hot Spring Microbial Mats
Authors: Sandbeck Kenneth A. , Ward David M.
Published: January 2020

The optimum temperatures for methanogenesis in microbial mats of four neutral to alkaline, low-sulfate hot springs in Yellowstone National Park were between 50 and 60°C, which was 13 to 23°C lower than the upper temperature for mat development. Significant methanogenesis at 65°C was only observed in one of the springs. Methane production in samples collected at a 51 or 62°C site in Octopus Spring was increased by incubation at higher temperatures and was maximal at 70°C. Strains of
Methanobacterium thermoautotrophicum
were isolated from 50, 55, 60, and 65°C sites in Octopus Spring at the temperatures of the collection sites. The optimum temperature for growth and methanogenesis of each isolate was 65°C. Similar results were found for the potential rate of sulfate reduction in an Icelandic hot spring microbial mat in which sulfate reduction dominated methane production as a terminal process in anaerobic decomposition. The potential rate of sulfate reduction along the thermal gradient of the mat was greatest at 50°C, but incubation at 60°C of the samples obtained at 50°C increased the rate. Adaptation to different mat temperatures, common among various microorganisms and processes in the mats, did not appear to occur in the processes and microorganisms which terminate the anaerobic food chain. Other factors must explain why the maximal rates of these processes are restricted to moderate temperatures of the mat ecosystem.
Aerosol stability of infectious and potentially infectious reovirus particles
Authors: Adams D J , Spendlove J C , Spendlove R S , Barnett B B
Published: January 2020

The aerosol stability of two particle forms, infectious and potentially infectious, of reovirus were examined under static conditions for a range of relative humidities at 21 and 24 degrees C. Virus aerosolization efficiency was determined for two methods of dissemination: Collison nebulizer and Chicago atomizer. Suspensions of Bacillus subtilis var. niger spores were added to reovirus preparations that included both particle forms and disseminated into a dynamic aerosol toroid to estimate the physical decay of the aerosols. At 90 to 100% relative humidity, both reovirus particle forms showed less than 10-fold loss of infectivity after 12 h of aging. At lower relative humidities the aerosol decay curve showed rapid initial decay followed by a markedly lower decay rate. Our findings reveal that reovirus particles are relatively stable in the airborne state.
Role of Thin Fimbriae in Adherence and Growth of
Acinetobacter calcoaceticus
RAG-1 on Hexadecane
Authors: Rosenberg Mel , Bayer Edward A. , Delarea Jacob , Rosenberg Eugene
Published: January 2020

Acinetobacter calcoaceticus
RAG-1, a hydrocarbon-degrading bacterium which adheres avidly to hydrocarbons and other hydrophobic surfaces, possesses numerous thin fimbriae (ca. 3.5-nm diameter) on the cell surface. MR-481, a nonadherent mutant of RAG-1 which is unable to grow on hexadecane under conditions of limited emulsification and low initial cell density, lacks these fimbriae. Prolonged incubation of MR-481 in hexadecane medium enriched for partial adherence revertants. The reappearance of thin fimbriae was observed in all such revertant strains. RAG-1 cells and partial revertant strains were agglutinated in the presence of antibody, whereas MR-481 cells were not. Another mutant, AB15, which was previously isolated on the basis of its nonagglutinability in the presence of antibody, also lacked thin fimbriae and was conditionally nonadherent. Furthermore, strain AB15 was unable to grow on hexadecane medium. Adherence of RAG-1 cells to hexadecane was considerably reduced after shearing treatment. The material removed from the cell surface by shearing of RAG-1 and the partial revertant strains yielded a single antigenic band in RAG-1 and partial revertant strains, as observed by crossed immunoelectrophoresis. This band was absent in both fimbriae-less mutants, MR-481 and AB15. The data demonstrate that the thin fimbriae of RAG-1 (i) are a major factor in adherence to polystyrene and hydrocarbon, (ii) may be crucial in enabling growth of cells on hexadecane, and (iii) constitute the major cell surface agglutinogen.
Adaptation to Cadmium by
Klebsiella aerogenes
Growing in Continuous Culture Proceeds Mainly via Formation of Cadmium Sulfide
Authors: Aiking Harry , Kok Karin , van Heerikhuizen Harm , van 't Riet Jan
Published: January 2020

The adaptation of
Klebsiella aerogenes
to high levels of cadmium was studied in continuous culture under conditions of glucose limitation. When up to 6 × 10
−4
M cadmium was added to a culture in steady state, growth ceased instantaneously but resumed within 5 h (dilution rate, 0.1 h
−1
). When again in steady state, these adapted cells exhibited a far greater tolerance to cadmium than did unadapted cells (not previously exposed to cadmium) when tested on solid media containing different concentrations of cadmium. This relative insensitivity of adapted cells to cadmium was subsequently lost in continuous culture within 5 days after omitting cadmium from the influent medium. Thus, the phenomenon was an inducible physiological process. Adapted cells contained substantial amounts of cadmium (up to 2.4% of the bacterial dry weight). The cadmium content of the cells was dependent on growth conditions and was found to be proportional to the inorganic sulfide content of the cells in all cases. This suggested that formation of CdS is probably the most important mechanism of detoxification in this organism. The presence of large numbers of electron-dense granules on the cell surface (absent in cultures without added cadmium) provided additional support for this conclusion.
Cocultivation of Legionella pneumophila and free-living amoebae
Authors: Tyndall R L , Domingue E L
Published: January 2020

Studies of the interaction of Legionella pneumophila with free-living amoebae showed that Naegleria lovaniensis and Acanthamoeba royreba could use L. pneumophila as a sole food source. However, growth of the amoebae on nonnutrient agar plates seeded with L. pneumophila was slower than growth on nonnutrient agar plates seeded with Escherichia coli. On inoculation of L. pneumophila into axenic cultures of N. lovaniensis and A. royreba, 99.9% of the L. pneumophila was destroyed within 24 h. After several weeks, however, some amoeba cultures became chronically infected and supported the growth of L. pneumophila. Amoebae exposed to L. pneumophila and containing adhered L. pneumophila, L. pneumophila antigens, or both, showed no increased pathogenic potential on intranasal inoculation of weanling mice. Similarly, L. pneumophila propagated in chronically infected amoeba cultures showed no increase in virulence on intraperitoneal inoculation of guinea pigs relative to L. pneumophila grown in yeast extract broth.
Nonstaining (KOH) method for determination of gram reactions of marine bacteria
Authors: Buck J D
Published: January 2020

A rapid nonstaining (KOH) method for the determination of the Gram reactions of bacteria is described, and its application to marine isolates is discussed. All gram-positive and gram-negative results obtained by Gram staining were confirmed by the KOH method. Gram-variable bacteria produced equivocal results.
Application of halophilic nuclease H of Micrococcus varians subsp. halophilus to commercial production of flavoring agent 5'-GMP
Authors: Kamekura M , Hamakawa T , Onishi H
Published: January 2020

RNA was degraded at 60 degrees C for 24 h by halophilic nuclease H in supernatants from broth cultures of Micrococcus varians subsp. halophilus containing 12% NaCl. Since contaminating 5'-nucleotidase exhibited almost no activity under these conditions, the 5'-GMP formed could be recovered from the reaction mixture, and the yield was 805 mg from 5 g of RNA.
Production of a Thermostable β-
d
-Galactosidase by
Alternaria alternata
Grown in Whey
Authors: Macris Basil J.
Published: January 2020

In the course of exploring new microbial sources of extracellular β-
d
-galactosidase (EC. 3.2.1.23),
Alternaria alternata
was found to excrete elevated quantities of a thermostable form of the enzyme when cultivated in whey growth medium. Optimum cultural conditions for maximum enzyme production were a whey lactose concentration of 6%, supplementation of the medium with 0.050 M (NH
4
)
2
SO
4
, an inoculum size of 10
3
conidia per ml, and a cultivation time at 28 to 30°C of 5 days. The fungus utilized whey lactose for the production of the enzyme most efficiently, and the observed maximum yield, 280 nanokatals of hydrolyzed
o
-nitrophenyl-β-
d
-galactopyranoside per g of whey lactose, was comparable to maximum yields reported for certain commercial fungi. The optimum pH and temperature of the enzymatic reaction were 4.5 to 5.5 and 60 to 70°C, respectively, and the enzyme lost half of its activity when heated at 65°C for 84 min. These properties make the enzyme particularly suitable for processing acid and less-acid (pH 5 to 6) dairy products and by-products.
Isolation of indigenous enteroviruses from chemically treated and dewatered sludge samples
Authors: Goddard M R , Bates J , Butler M
Published: January 2020

Samples of wastewater sludge were examined for infectious enteroviruses before and after they had been chemically conditioned and dewatered. The least virus was recovered from the cake produced by filter pressing of sludge, which had a greatly increased solids content (39 to 45% [wt/vol]) relative to the untreated sludge (4.2 to 6.2% [wt/vol]) and in one plant was at pH 11 due to the lime conditioner used. Conditioning with a cationic polyelectrolyte before dewatering by centrifugation produced a watery sludge (2.7 to 5.3% [wt/vol]) from which high titers of infectious virus were recovered which were often greater than those isolated from the untreated sludge (0.6 to 1.4% [wt/vol]). This was thought to be due to saturation of virus and sludge floc adsorption sites by the polyelectrolyte, resulting in the liberation of virions from the sludge solids.
Microbiological quality of five potato products obtained at retail markets
Authors: Duran A P , Swartzentruber A , Lanier J M , Wentz B A , Schwab A H , Barnard R J , Read R B
Published: January 2020

The microbiological quality of frozen hash brown potatoes, dried hash brown potatoes with onions, frozen french fried potatoes, dried instant mashed potatoes, and potato salad was determined by a national sampling at the retail level. A wide range of results was obtained, with most sampling units of each products having excellent microbiological quality. Geometric mean aerobic plate counts were as follows: dried hash brown potatoes, 270/g; frozen hash brown potatoes with onions, 580/g; frozen french fried potatoes 78/g; dried instant mashed potatoes, 1.1 x 10(3)/g; and potato salad, 3.6 x 10(3)/g. Mean values of coliforms, Escherichia coli, and Staphylococcus aureus were less than 10/g.
Rapid identification of microorganisms by circular-intensity differential scattering
Authors: Salzman G C , Griffith J K , Gregg C T
Published: January 2020

There is a pressing need in clinical medicine for rapid identification of microorganisms. We describe a method that has the potential for such rapid identification: circular-intensity differential scattering, which is based on the differential scattering of left and right circularly polarized light. The scanning time required to obtain the spectral signature of an organism is about 4 min. Using a commercial circular dichrograph modified to measure circular intensity differential scattering at 90 degrees, we obtained significantly different spectra for five different crude influenza viruses. Salmonella typhimurium TA98 and TA100, and Escherichia coli HB101, HB101(pBR322), and HB101(pMB9). Purified supercoiled plasmid pBR322 DNA was readily distinguishable from linear pBR322 DNA; such differences in nucleic acid packaging may be significant factors in the discriminatory power of this technique.