bluuebunny/crossref_metadata_2025 huggingface dataset:
Methionine overproduction by Saccharomycopsis lipolytica
Authors: Morzycka E , Sawnor-Korszyńska D , Paszewski A , Grabski J , Raczyńska-Bojanowska K
Published: January 2020

Six ethionine-resistant (Etr) regulatory mutants of Saccharomycopsis lipolytica Sl/1 overproducing methionine have been isolated. Five of them are also resistant to seleno-methionine. The activity of homocysteine synthase (O-acetyl-L-hormoserine-acetate lyase, adding hydrogen sulfide) is derepressed in these mutants and is not susceptible to the methionine-mediated repression. The pool of free methionine in Etr mutants is enhanced 1.5 to 18 times, and incorporation of 35S into methionine is 1.5 to 50 times higher than that in the wild strain. Neither accumulation of endogenous free methionine in Etr mutants nor the uptake of exogenous methionine is accompanied by an increase in the S-adenosylmethionine pool. This implies compartmentation of methionine metabolism in S. lipolytica.
Influence of postirradiation incubation temperature on recovery of radiation-injured Clostridium botulinum 62A spores
Authors: Chowdhury M S , Rowley D B , Anellis A , Levinson H S
Published: January 2020

The number of colonies formed by unirradiated Clostridium botulinum 62A spores was independent of temperature, in the range from 20 to 45 degrees C (in 5 degrees C increments); no colonies developed at 50 degrees C. Spores irradiated at 1.2 or 1.4 Mrads produced more macrocolonies at 40 degrees C than at higher or lower temperatures. Apparently, radiation-injured spores were capable of repair of 40 degrees C than at the other temperatures studied. More than 99% of the radiation (1.2 Mrads) survivors were injured and were unable to form macrocolonies in the presence of 5% NaCl. The germinated radiation-injured spores were also sensitive to dilution, resulting in the loss of viability of 77 to 79% of the radiation survivors. At 30 and 40 degrees C, the irradiated spores did not differ significantly in the extent of germination (greater than 99% at both 30 and 40 degrees C), emergence (64% at 30 degrees C and 67% at 40 degrees C), and the maximum number of emerged cells that started to elongate (69% at 30 degrees C and 79% at 40 degrees C). However, elongation was remarkably more extensive at 40 degrees C than at 30 degrees C. Many elongated cells lysed within 48 h at 30 degrees C, indicating an impaired repair mechanism. If the radiation-injured spores were incubated at 40 degrees C in the recovery (repair) medium for 8 to 10 h, they germinated, emerged, and elongated extensively and were capable of repair. If, after 8 to 10 h at 40 degrees C, these cultures were shifted to 30 degrees C, the recovery at 30 increased by more than eightfold, resulting in similar colony counts at 30 and 40 degrees C. Thus, repair appeared to be associated with outgrowth. Repair did not occur in the presence of chloramphenicol at 40 degrees C, whereas penicillin had no effect, suggesting that the repair involved protein synthesis but did not require multiplication.
Requirement for a Growth Substrate During Lignin Decomposition by Two Wood-Rotting Fungi
Authors: Kirk T. Kent , Connors W. J. , Zeikus J. Gregory
Published: January 2020

Decomposition of
14
C-labeled lignin to
14
CO
2
by the lignin-decomposing fungi
Phanerochaete chrysosporium
and
Coriolus versicolor
required a growth substrate such as cellulose or glucose. Growth with lignin as sole carbon addition to an otherwise complete medium was negligible.
Ring Hydroxylation of
p
-Chlorophenylacetate by an
Arthrobacter
Strain
Authors: Deo P. G. , Alexander M.
Published: January 2020

Resting cell suspensions of a strain of
Arthrobacter
grown on phenylacetate converted
p
-chlorophenylacetate to two products. One of the products was identified as 4-chloro-3-hydroxyphenylacetate.
Spiral plate count method for the examination of raw and pasteurized milk
Authors: Donnelly C B , Gilchrist J E , Peeler J T , Campbell J E
Published: January 2020

The spiral plate count method (SPLPC) was compared with the standard plate count (SPC) method by examining 201 samples of raw and pasteurized milk. Although the means of the two methods differed significantly at alpha = 0.01,the difference was less than 10% and was not considered to be of any practical importance. The pooled replicate variances of both methods were less than 0.003, indicating good agreement between duplicate plates, with the variance of the SPLPC slightly less than that of the SPC. We believe this study indicates that the SPLPC could be substituted for the SPC in the bacteriological examination of milk.
Colonization of rye green manure and peanut fruit debris by Aspergillus falvus and Aspergillus niger group in field soils
Authors: Griffin G J , Garren K H
Published: January 2020

Aspergillus flavus and Aspergillus niger group colonization of deep-plowed, decomposing rye green manure cover crops in peanut field soils was studied in four fields during 1972 and 1973; colonization of decomposing peanut fruits was studied in 1972 in two fields. A. flavus colonization of rye and peanut fruits was greater in soils of heavy texture, and an A. flavus population as high as 165 propagules per g of soil was observed in soil adjacent to rye, whereas A. flavus populations in soils not associated with rye were 18 propagules per g of soil or lower. Highest A. flavus populations in soil adjacent to decomposing peanut fruits were usually comparable to populations associated with rye. Little decomposing rye or peanut fruit colonization was generally observed by the A. flavus competitor, A. niger group. A. flavus may maintain or increase its inoculum potential by colonization of these and other moribund plant tissues.
Plasmids in Streptococcus lactis: evidence that lactose metabolism and proteinase activity are plasmid linked
Authors: Efstathiou J D , McKay L L
Published: January 2020

Populations of lactose positive (Lac+) and proteinase positive (Prt+) cells from Streptococcus lactis M18, C10, and ML3 grown at 39 degrees C gave rise to increasing proportions of Lac- Prt- clones. The deficiencies did not appear until after a number of generations at the elevated temperature, and the rate depended on the strain.Lac- Prt+ and Lac+ Prt- mutants were isolated after treatment with ethidium bromide. Plasmid deoxyribonucleic acid was isolated by cesium chloride-ethidium bromide equilibrium density gradient centrifugation from the parent cultures as well as from their Lac- Prt-, Lac- Prt+, and Lac+ Prt- mutants. Five distinct plasmid sizes of approximate molecular weights of 2,4, 8, 21, and 27 million were found in S. lactis C10, whereas the Lac- Prt- derivative lacked the 8- and 21-million-dalton plasmids, but the 8-million-dalton plasmid was present in the Lac-Att mutant. In S. lactis m18 five plasmids possessing molecular weights of about 2, 4, 10, 18 and 27 million were observed. The 10- and 18-million-dalton plasmids were not detected in the Lac- Prt- mutants, whereas the Lac- Prt+ derivative lacked only the 18-million-dalton plasmid and the Lac+ Prt- mutant lacked only the 10-million-dalton plasmid. In S. lactis ML3 five distinct plasmids, with approximate molecular weights of 2, 4, 8, 22, and 30 million, were present. The 8- and 22-million-dalton plasmids were not detected in the Lac- Prt- derivative, but the 8-million-dalton plasmid was present in the Lac- Prt+ mutant. The evidence suggests that lactose-fermenting ability and proteinase activity in these organisms are mediated through two distinct plasmids having molecular weights of 8 x 10(6) to 10 x 10(6) for proteinase activity and 18 x 10(6) to 22 x 10(6) for lactose metabolism.
Aflatoxin and sterigmatocystin contamination of pistachio nuts in orchards
Authors: Sommer N F , Buchanan J R , Fortlage R J
Published: January 2020

Aspergillus flavus and A. versicolor were both shown to be weak pathogens of developing pistachio fruits, producing aflatoxin and sterigmatocystin, respectively. Aflatoxin concentrations approached those reported in cereal and legume seeds. Fungus lesions on the first hulls were followed by invasion of seeds despite the sclerified shell. Infections and mycotoxins present before harvest would presumably lead to further build-up after harvest if drying was slow or storage was under high humidity.
Studies on bacteriophage distribution: virulent and temperate bacteriophage content of mammalian feces
Authors: Dhillon T S , Dhillon E K , Chau H C , Li W K , Tsang A H
Published: January 2020

Freshly voided samples of the feces of cows, pigs, and humans were analyzed for the enumeration of cell-free plaque-forming units (PFU) of coliphages and Salmonella phages. Coliphage PFU counts per gram (wet weight) of feces were found to range from less than 10(1) to greater than 10(7). Salmonella phages were found in three out of five porcine samples, but none were found in the four bovine samples analyzed. Virulent coliphages related to the phiX174/S13 serological group showed some "habitat preference" in that the S13 type of phages was found only in pig feces, whereas the phiX174 type of phages was found only in cow dung. Temperate coliphages were detectable in a majority of samples of both human and porcine origin but were infrequently found in bovine samples. About 80% of the temperate coliphages of fecal origin have been found to be serologically related to phage HK022 (Dhillon and Dhillon, 1973), and all are efficiently inducible by ultraviolet light irradiation. However, considerable diversity with the group was found when the prophage immunity pattern of 10 randomly selected isolates was examined.
Effect of dissolved aromatic hydrocarbons on the growth of marine bacteria in batch culture
Authors: Calder J A , Lader J H
Published: January 2020

Dissolved aromatic hydrocarbons were found to decrease growth rate and maximum cell density of marine bacteria in batch cultures. The magnitude of the decrement was observed to be a function of concentration of the hydrocarbon and inherent toxicity. The inherent toxicity was observed to increase inversely with solubility such that naphthalene at 100 muM concentration demonstrated a toxic effect similar to benzopyrene at 0.02 muM. A partial oxidation product of naphthalene was found to be more effective in decreasing growth parameters than naphthalene at equivalent concentrations and to cause complete cessation of growth at the higher concentrations permitted by its polar structure.
High Production of Kojic Acid Crystals by
Aspergillus parasiticus
UNBF A12 in Liquid Medium
Authors: Lin M. T. , Mahajan J. R. , Dianese J. C. , Takatsu A.
Published: January 2020

The crystalline compound produced in large quantity in liquid medium by
Aspergillus parasiticus
UNBF A12, a high aflatoxin-producing strain isolated from the air in the Federal District of Brazil, was identified as kojic acid. The effect of pH on the production of crystalline kojic acid and aflatoxins by the strain was studied. Fourteen single spore isolates were evaluated for their capacity to produce kojic acid crystals and aflatoxins.
Heat-induced requirements for sucrose or magnesium for expression of heat resistance in Bacillus cereus forespores
Authors: Busta F F , Baillie E , Murrell W G
Published: January 2020

The addition of 0.6 M sucrose of 0.016 M Mg2+ to the enumeration medium was required for early expression of heat resistance (10 min at 70 degrees C) in stage V Bacillus cereus forspores. The addition of Mg2+ to the sporulation medium did not remove this requirment for sucrose of Mg2+. The heat damage did not affect forespore germination or outgrowth, but injured cells in the absence of sucrose or Mg2+ were not capable of cell division. The heat-induced sublethal damage apparently affected the forspore component(s) that could be repaired or was capable of normal function in the presence of added Mg2+ or sucrose.
An obligate osmophilic yeast from honey
Authors: Munitis M T , Cabrera E , Rodriguez-Navarro A
Published: January 2020

An obligate osmophilic yeast that requires high sugar concentrations (10 to 20% glucose) for growth was identified as Saccharomyces bisporus var. mellis. Optimum growth for this strain was at 60% glucose. Several non-assimilable compounds permitted growth at glucose concentrations below the minimum requirement and stimulated growth at glucose concentrations above the minimum. No correlation existed between growth stimulation and spheroplast stabilization capacities of the compounds examined.
Influences of soil acidity on Streptomyces populations inhabiting forest soils
Authors: Hagedorn C
Published: January 2020

The Streptomyces populations inhabiting five acidic forest soils were examined. It was found that lowering the pH of a medium selective for streptomycetes (starch-casein agar) to the pH of the particular soil horizon being plated influenced both the total numbers and types of streptomycetes that were isolated from the soils examined in this study. On the acidified medium both the numbers of streptomycetes and the percentage of total bacteria on the plates represented by streptomycetes increased (as compared with the same medium with a pH of 7.2). These differences were greatest on the isolations from the most acid soils. The largest concentrations of streptomycetes were found in the surface horizon (0 to 15 cm) and the litter layer immediately over the surface mineral horizon. Acidity tolerance tests demonstrated that random samplings of isolates contained acidophilic, neutrophilic, and acidoduric strains, with the largest numbers of acidophiles being found on the acidified media from the most acid soils. There were no differences between overall utilization of selected carbohydrates among the isolates taken from either the neutral or acidic media, although a larger proportion of the acid media isolates produced acid from the carbohydrates. Evidence is presented which indicates that different types of streptomycetes were isolated on the acid media, and possible reasons for the presence of these acid-tolerant populations are discussed.
Attachment of the ciliate Epidinium Crawley to plant fragments in the sheep rumen
Authors: Bauchop T , Clarke R T
Published: January 2020

High concentrations of the ciliate Epidinium Crawley are associated with damaged regions of fresh plant material undergoing digestion in the sheep rumen. This finding supports that postulate that sequestration in the rumen explains the low rate of passage of protozoa despite the high flow rate of liquid from the rumen. The maintenance of Epidinium in the rumen, despite their slow growth rate, is also explained.
Screeing of toxic isolates of Fusarium poae and Fusarium sporotrichiodes involved in causing alimentary toxic aleukia
Authors: Yagen B , Joffe A Z
Published: January 2020

A total of 131 isolates of Fusarium poae and F. sporotrichioides from overwintered cereals, which were associated with the alimentary toxic aleukia toxicoses in the Soviet Union, were tested for their ability to produce T-2 toxin [4 beta, 15 diacetoxy-8alpha-(3-methylbutyryloxy)-12,13-epoxytrichothec-9-en 3alpha-ol]. The presence of T-2 toxin was determined by thin-layer chromatography, gas-liquid chromatography, spectroscopic analyses, and the rabbit skin test. A good correlation was demonstrated between T-2 toxin dectetion by thin-layer chromatography and inflammatory skin reactions of rabbits.
Use of hydroxyapatite-coasted glass beads for preclinical testing of potential antiplaque agents
Authors: Sudo S Z , Schotzko N K , Folke L E
Published: January 2020

Methods for rapid preclinical testing of antiplaque agents in vitro using hydroxyapatite (HT)-coated glass beads are described. The assays developed could reliably detect (i) prevention of growth in the culture fluid or on the HT surfaces, (ii) the effect of transient exposure of a bactericidal agent on the viability of cells in a preformed bacterial mat, (iii) reversible adsorption of a bactericidal agent on an HT surface, and (iv) the ability of an agent to inhibit adsorption of Streptococcus sanguis to an HT surface or to salivary proteins adsorbed to an HT surface.
Tremorgenic Mycotoxin from
Penicillium paraherquei
Authors: Yoshizawa Takumi , Morooka Nobuichi , Sawada Yuzuru , Udagawa Shun-Ichi
Published: January 2020

A tremorgenic mycotoxin was isolated from
Penicillium paraherquei
Abe ex G. Smith and identified as verruculogen. It was produced at the rate of approximately 1 mg/g of the dried fungal mycelium cultured on peptone-enriched Czapek-Dox medium at 28�C.
Degradation of Ochratoxin A by a Ruminant
Authors: Hult Karl , Teiling Anna , Gatenbeck Sten
Published: January 2020

The fate of ochratoxin A during incubation with contents from the four stomachs of the cow was studied. It was concluded that ochratoxin A was cleaved into the nontoxic ochratoxin α and phenylalanine by the contents from all but the abomasum.
Computer-assisted analysis of adenosine triphosphate data
Authors: Erkenbrecher C W , Crabtree S J , Stevenson L H
Published: January 2020

A computer program has been written to assist in the analysis of adenosine 5'-triphosphate data. The program is designed to calculate a dilution curve and to correct sample and adenosine 5'-triphosphate standard data for background and dilution effects. In addition, basic statistical parameters and estimates of biomass carbon are also calculated for each group of samples and printed in a convenient format. The versatility of the program to analyze data from both qauatic and terrestrial samples is noted as well as its potential use with various types of instrumentation and extraction techniques.
Paint Deterioration as a Result of the Growth of
Aureobasidium pullulans
on Wood
Authors: Horvath R. S. , Brent M. M. , Cropper D. G.
Published: January 2020

Growth of
Aureobasidium
was noted on both painted and unpainted wood surfaces but not on painted glass slides, indicating that the source of carbon and energy for growth was not associated with paint components but was probably supplied by the wood. Several aromatic compounds related to aromatic extractives of wood were shown to support growth of this fungus.
Survival of coliform bacteria in sewage sludge applied to a forest clearcut and potential movement into groundwater
Authors: Edmonds R L
Published: January 2020

Anaerobically digested dewatered sludge (10 to 15 cm thick) was applied to a forest clearcut as a fertilizer source in northwest Washington on gravelly glacial outwash soil. This sludge is not microbiologically sterile and may contain pathogenic organisms. Fecal coliform bacterial counts in sludge applied in summer (July) fell from 1.08 X 10(5) to 358/g in 204 days and to 0/g in 267 days. Dieoff appeared more rapid in winter (January)-applied sludge, when colnts fell from 1.2 X 10(5) to 20/g in 162 days. Initial death rates were related to sludge temperature, moisture, pH, physical composition, and microbial competition. Aftergrowth of fecal coliforms occurred in warm summer and fall months, but counts were of similar magnitude to background levels in forest soils, where a maximum count of 54/g was recorded. Total coliform counts in fresh sludge ranged from 1.4 X 10(4) to 1.9 X 10(6)/g. Numbers stabilized at 10(3) to 10(4)/g in spring, fall, and summer, with lower numbers in winter. Both total and fecal bacteria moved from the sludge to the soil beneath, but few penetrated past the first 5 cm. The soil acts as an effective biological filter. Few fecal coliform bacteria were recorded in the groundwater, generally being less than 5/100 ml and mostly 0/100 ml. A maximum count of 52/100 ml was recorded. Groundwater contamination from vertical movement of potential pathogens appears unlikely, but hazards from surface runoff and direct handling in the first year may arise.
Biodegradability of [14C]methylcellulose by activated sludge
Authors: Blanchard F A , Takahashi I T , Alexander H C
Published: January 2020

Three Methocel methylcellulose ethers of 1.9 degree of substitution with [14C]methyl labels were shown to be biodegradable using batch-type activated sludge tests. The maximum rate for conversion to 14CO2, attained after 1 week, was only 0.62 mg of methylcellulose/g of mixed liquor volatile solids per day. In 20 days, 55 to 73% of the radioactivity had been removed from solution as 14CO2, and the suspended solids contained 12 to 15% of the original radioactivity. Only 4% of the original methylcellulose appeared to be polymeric after the 20-day period. Thin-layer chromatography of supernatant liquid indicated at least two degradation products.
Identification of mycotoxins produced by species of Fusarium and Stachybotrys obtained from Eastern Europe
Authors: Szathmary C I , Mirocha C J , Palyusik M , Pathre S V
Published: January 2020

Isolates of Fusarium and Stachybotrys spp. and crude extracts from these fungi were obtained from Hungary and the U.S.S.R. and used for the evaluation of the mycotoxins they produced. The cultures were grown on millet and oats and extracted in Budapest, Hungary (Veterinary Medical Research Institute) and chemically analyzed at the University of Minnesota using thin-layer chromatography (TLC), gas-liquid chromatography (GLC), gas chromatograph-mass spectrometry (GC-MS), and the rat skin bioassay. Zearalenone was found in most of the Fusarium cultures, T-2 toxin, neosolaniol, T-2 tetraol, and HT-2 toxin were found in extracts of Fusarium poae and F. sporotrichioies. A special effort was made to isolate the steroid-like toxins reported in the early Russian literature as sporofusarin and poaefusarin. None of the extracts from the Fusarium species yielded poaefusarin or sporofusarin when analyzed by our chemical methods or by those of L.E. Olifson, S.M. Kenina, and V.L. Kartashova, 1972. We therefore accounted for the toxicity of the Fusarium extracts as due to the 12,13,epoxytrichothecenes. One culture of Stachybotrys alternans yielded a macrocyclic ester of 12,13-epoxytrichothecene which, upon hydrolysis, yielded verrucarol; a steroid-like molecule (SB-3) was also isolated. The former had skin-irritant activity but SB-3 did not; the latter exhibited cardiac activity on the heart of the cockroach.
Quantitative requirements for exponential growth of Alcaligenes eutrophus
Authors: Repaske R , Repaske A C
Published: January 2020

Quantitative nutrient requirements for unrestricted autotrophic growth of Alcaligenes eutrophus were determined. Minimum saturating concentrations of Mg2+, SO42-, PO43-, Fe3+, and Na2+ for an optical density increase of 2 were 10(-4) M 8 X10(-5) M, 5 X 10(-4) to 6 X 10(-4) M, 10(-5) M, and 10(-7) to 2 X 10(-7) M, respectively. Trace metal requirements for cobalt, chromium, and copper were also demonstrated, but minimum concentrations could not be determined because other reagents contributed a high background of these metals. Under certain conditions an apparent response to zinc was observed, although other experiments suggest the zinc salt contained another metal that was required for growth. Poly-beta-hydroxybutyrate biosynthesis was shown to be initiated by a magnesium or sulfate deficiency as well as by a nitrogen or phosphate deficiency.
Dense autotrophic cultures of Alcaligenes eutrophus
Authors: Repaske R , Mayer R
Published: January 2020

Alcaligenes eutrophus was grown autotrophically in 23-liter batch cultures in a controlled H2-O2-CO2 atmosphere. It was demonstrated that the need for periodic supplements of individual nutrients could be anticipated before cell growth depleted these nutrients to the point of becoming growth rate limiting. As a result, exponential growth was extended to optical densities of 44, with doubling times maintained at 2 h. Cultures having an initial optical density of 0.040 to 0.70 reached the final optical density of 60 in about 25 h. The final viable count was 1.2 X 10(11) cells per ml, and the dry weight was 25 g/liter.
Enhanced Dissolution of Oil Shale by Bioleaching with Thiobacilli
Authors: Meyer W. Craig , Yen T. F.
Published: January 2020

Oil shale was subjected to bioleaching by cultures of thiobacilli. From X-ray, electron microprobe, and thin-section petrographic analysis, the shale matrix was found to contain tightly bonded carbonate minerals. When subjected to the bioproduced acids, these carbonate minerals were removed successively from the shale matrix. This process created pits and cavities which were gradually enlarged as indicated by scanning electron micrographs of samples subjected to leaching for varying lengths of time. At the end of 14 days, essentially all available carbonates had been depleted from the solid matrix. The effected increase in porosity and permeability of the oil shale then enhanced the exposure of fuel precursors, thus facilitating their production and conversion.
Myxobacters from Arid Mexican Soil
Authors: Brockman Ellis R.
Published: January 2020

Myxobacters were found to be common inhabitants of the arid soils from the Monterrey, Nuevo Leon, Mexico, area. Thirteen species of the genera
Myxococcus, Archangium, Cystobacter, Stigmatella, Polyangium
, and
Chondromyces
were isolated on a mineral salts agar supplemented with bakers' yeast and filter paper. Greater species diversity per soil sample was found in the region receiving 400 to 800 mm of annual rainfall as compared with soils from an area having only 200 to 400 mm of rainfall.
Autoflora in the upper respiratory tract of Apollo astronauts
Authors: Decelle J G , Taylor G R
Published: January 2020

The typical microbial inhabitants of the oral and nasal cavities of Apollo astronauts were identified before space flight and generally found to be similar to those previously reported for healthy male adults. Additional analyses of samples collected immediately after return of the Apollo 13, 14, 15, and 16 crew members to earth were performed to evaluate the effects of space travel on the microbial bioburden of the upper respiratory tract. In-flight cross-contamination and buildup of pathogens such as Staphylococcus aureus were noted, although significant increases in nonpathogenic species were absent. Other proposed alterations, such as dysbacteriosis (flooding of the mouth with a single species) and simplification of the autoflora, did not occur. Generally, the incidence and quantitation of each species after flight was within the preflight range, although the number of viable Haemophilus cells recovered from the mouth decreased significantly after space flight. Except for those minor alterations listed above, the aerobic and anaerobic bacterial components of the upper respiratory autoflora of Apollo astronauts was found to be stable after space flight of up to 295 h.
Concentration and purification of enteroviruses by membrane chromatography
Authors: Henderson M , Wallis C , Melnick J L
Published: January 2020

A simple procedure for the concentration and partial purification of enteroviruses from tissue culture harvests is described. After removal of acid-precipitating components with a cationic detergent, the detergent and most membrane-coating components were removed by treatment with a cationic-exchange resin. The resin effluent was then acidified, and the virus was adsorbed to epoxy-fiberglass membranes. Virus was then eluted with pH 11.5 glycine-NaOH buffer. Since this eluate contains no orgcentrated simply by acidifying the eluate and passing it through a smaller membrane than that used for the first concentration. As high as 500-fold concentrations can be achieved, with a high efficiency of recovery.
Definition of Bacteriophage Groups According to Their Lytic Action on Mesophilic Lactic Streptococci
Authors: Chopin M.-C. , Chopin A. , Roux C.
Published: January 2020

The lytic activity of 132 phages isolated during slow acid production in cheese factories situated in all the dairying regions of France during the past 16 years has been determined on 291 strains of mesophilic lactic streptococci. The results have been treated according to a method of analysis of data so as to establish a classification. Six groups of phages have thus been formed. Sixty-six percent of the phages studied, which are very similar and for the most part nonspecific to one species, have been gathered together in one group. On the other hand, a classification of the bacterial strains has been made on their sensitivity to the phages. Six groups, each corresponding to one of these groups of phages, have thus been defined. One of them accounts for 40% of the strains studied, of which certain ones are sensitive to a large number of phages.
Products Formed from Analogues of 1,1,1-Trichloro-2,2-Bis(
p
-Chlorophenyl) Ethane (DDT) Metabolites by
Pseudomonas putida
Authors: Subba-Rao R. V. , Alexander M.
Published: January 2020

Cultures of
Pseudomonas putida
growing in solutions with diphenylmethane as sole carbon source formed 1,1,1′,1′-tetraphenyldimethyl ether. The product was identified by gas chromatography, mass spectrometry, and infrared and nuclear magnetic resonance spectrometry. The formation of benzophenone, benzhydrol, and phenylglycolic acid was established by gas chromatography and mass spectrometry. Similar techniques also revealed that phenylacetic acid was a major metabolite. Resting cell suspensions converted benzhydrol to phenyl-glycolic acid and products tentatively identified as hydroxybenzhydrols and a hydroxybenzophenone. Cell suspensions of the bacterium also converted the tetraphenyldimethyl ether to benzhydrol and benzophenone. Possible pathways for the degradation of these analogues of 1,1,1-trichloro-2,2-bis(
p
-chlorophenyl)ethane (DDT) metabolites are discussed.
Deconjugation of bile acids by intestinal lactobacilli
Authors: Gilliland S E , Speck M L
Published: January 2020

Lactobacillus species normally found in the intestinal tract of humans varied in the ability to deconjugate bile acids, whereas laboratory strains of Lactobacillus acidophilus deconjugated both glycocholate and taurocholate. All isolates of L. acidophilus from human feces deconjugated taurocholate, whereas only one of six deconjugated glycocholate. None of 13 isolates identified as L. casei deconjugated taurocholate, whereas 9 deconjugated glycocholate. The deconjugating system of L. acidophilus appeared to be constitutive, required low oxidation-reduction potential, and was most active at pH 6. No degradation beyond deconjugation was detected.
Semiquantitative Plate Assay for Determination of Cellulase Production by
Trichoderma viride
Authors: Montenecourt Bland S. , Eveleigh Douglas E.
Published: January 2020

A plate clearing assay was devised to screen for high-producing cellulase mutants of
Trichoderma viride
. The method employs (i) the use of either rose bengal or oxgall to limit colony size and (ii) Phosfon D (tributyl-2, 4-dichloroben-zylphosphonium chloride) to enhance cellulase detection, in combination with acid-swollen cellulose on agar plates. The method was used to isolate constitutive cellulase mutants of
T. viride
and should prove useful for isolating high-producing mutants from a range of organisms. This technique has been also used to determine the concentration at which glucose and glycerol inhibit cellulase synthesis by catabolite repression in the wild-type strains.
Ionic bonding, the mechanism of viral uptake by shellfish mucus
Authors: Di Girolamo R , Liston J , Matches J
Published: January 2020

An investigation was conducted to determine the processes involved in the contamination of shellfish by viruses. Results of binding-release studies show that the process involves the attachment of viruses to mucus secreted, and then ingested, by shellfish during feeding. Analysis of the mucus-virus bond involved selective degradation of the mucus and use of chemical agents to block carboxyl and sulfate groups on the mucus. Results obtained indicate that the attachment of virus to mucus is primarily ionic and involves the binding of viral particles to sulfate radicals on the mucopolysaccharide moiety of shellfish mucus.
Microbial Transformations of Selenium
Authors: Doran J. W. , Alexander M.
Published: January 2020

Resting cell suspensions of a strain of
Corynebacterium
isolated from soil formed dimethyl selenide from selenate, selenite, elemental selenium, selenomethionine, selenocystine, and methaneseleninate. Extracts of the bacterium catalyzed the production of dimethyl selenide from selenite, elemental selenium, and methaneseleninate, and methylation of the inorganic Se compounds was enhanced by
S
-adenosylmethionine. Neither trimethylselenonium nor methaneselenonate was metabolized by the
Corynebacterium.
Resting cell suspensions of a methionine-utilizing pseudomonad converted selenomethionine to dimethyl diselenide. Six of 10 microorganisms able to grow on cystine used selenocystine as a sole source of carbon and formed elemental selenium, and one of the isolates, a pseudomonad, was found also to produce selenide. Soil enrichments converted trimethylselenonium to dimethyl selenide. Bacteria capable of utilizing trimethylselenonium, dimethyl selenide, and dimethyl diselenide as carbon sources were isolated from soil.
End products and fermentation balances for lactic streptococci grown aerobically on low concentrations of glucose
Authors: Brown W V , Collins E B
Published: January 2020

Maximum acetate produced aerobically by Streptococcus diacetilactis and Streptococcus cremoris was 14% of 1 to 7 mumol of glucose/ml in a partially defined medium that contained lipoic acid. Y (glucose) values were 35.3 (S. diacetilactis) and 31.4 (S. cremoris) with low concentrations (1 to 7 mumol/ml) of glucose in the medium and 21 (S. diacetilactis) with higher concentrations (6 to 15 mumol/ml). Y (adenosine 5'-triphosphate) values for the bacteria, determined by taking into account the end products produced, were 15.6 and 13.9 for S. diacetilactis and S. cremoris, respectively, in the partially defined medium containing 1 to 7 mumol of glucose/ml and higher (21.5 and 18.9, respectively) in a complex medium that contained 2 mumol of glucose/ml. Addition of citrate in addition to glucose did not result in higher molar growth yields.
Microbial Decomposition of Synthetic
14
C-Labeled Lignins in Nature: Lignin Biodegradation in a Variety of Natural Materials
Authors: Hackett W. F. , Connors W. J. , Kirk T. K. , Zeikus J. G.
Published: January 2020

Lignin biodegradation in a variety of natural materials was examined using specifically labeled synthetic
14
C-lignins. Natural materials included soils, sediments, silage, steer bedding, and rumen contents. Both aerobic and anaerobic incubations were used. No
14
C-labeled lignin biodegradation to labeled gaseous products under anaerobic conditions was observed. Aerobic
14
C-labeled lignin mineralization varied with respect to type of natural material used, site, soil type and horizon, and temperature. The greatest observed degradation occurred in a soil from Yellowstone National Park and amounted to over 42% conversion of total radioactivity to
14
CO
2
during 78 days of incubation. Amounts of
14
C-labeled lignin mineralization in Wisconsin soils and sediments were significantly correlated with organic carbon, organic nitrogen, nitrate nitrogen, exchangeable calcium, and exchangeable potassium.
Thermal resistance of Bacillus subtilis var. niger in a closed system
Authors: Peeler J T , Reyes A L , Crawford R G , Wehby A J , Campbell J E
Published: January 2020

The heat resistance of Bacillus subtilis var. niger has been measured from 85 to 125 degrees C using moisture levels of percent relative humidity (%RH) less than or equal to 0.001 to 100 in a closed system. Five curves have been presented to characterize the thermal destruction, using thermal death times defined as F values at a given combination of three moisture and temperature conditions. Reductions of 99.99% (4-log10 cycles) of the initial population were estimated for the three moisture conditions. At 110 degrees C, the expected time for a 4-log10 reduction was 1.1 h at %RH = 100, 3.1 h at %RH less than or equal to 0.1 and 54 h at %RH = 10.7. Goodness-of-fit tests to examine the adequacy of three polynomial models failed to indicate a trend. The linear model (from which estimates of D are obtained) was satisfactory for estimating the thermal death times (%RH less than or equal to 0.1) in the plate count range. The estimates based on observed thermal death times and D values for the %RH = 100 diverged so that D values generally gave a more conservative estimate over the temperature range 90 to 125 degrees C. Estimates of ZF and ZL ranged from 32.1 to 58.3 degrees C for the %RH less than or equal to 0.1 and 100. A ZD value of 30.0 was obtained for data observed at %RH less than or equal to 0.1. The ZF results were obtained from plotting observed log times to achieve a 99.99% reduction in the initial population versus temperature. Estimates of ZL and ZD were obtained by using linear estimates of L100 approximately equal to 4D and D values in a similar plot.
Production and Purification of Thermostable Amylase and Protease of
Thermomonospora viridis
Authors: Upton Mary E. , Fogarty William M.
Published: January 2020

Maximum yields of amylase were produced by the thermophilic actinomycete
Thermomonospora viridis
in a modified Simpson and McCoy medium containing 1.5% corn starch and 0.5% mycological peptone with an initial pH 7.0. Best yields of amylase were obtained after incubation for 48 h, when the pH of the medium had risen to 8.2. Amylase was purified 313-fold by precipitation with
n
-propyl alcohol, dialysis against tap water, adsorption on Ca
3
(PO
4
)
2
, and fractionation on Sephadex G-100. Protease was produced in nutrient broth containing 0.5% starch and 1.0% corn steep liquor and at an initial pH 7.0. Maximum yields of protease were produced after 42 h. The protease was purified 54-fold by precipitation with
n
-propyl alcohol, dialysis against tap water, adsorption on Ca
3
(PO
4
)
2
, and fractionation on Sephadex G-200.
Methods for Growing
Spirillum lipoferum
and for Counting It in Pure Culture and in Association with Plants
Authors: Okon Yaacov , Albrecht Stephan L. , Burris R. H.
Published: January 2020

Methods are described for growing
Spirillum lipoferum
in quantities sufficient to serve as inoculant in field trials of its associative N
2
-fixing ability with higher plants and as a source of cells for the preparation of nitrogenase, cytochromes, respiratory enzymes, etc. A heavy inoculum of
S. lipoferum
grown on NH
4
+
was transferred to a medium of minimal nitrogen content, and initial rapid growth at the expense of residual combined nitrogen was replaced later by slower growth on N
2
. Conversion to N
2
fixation was prompt upon exhaustion of fixed nitrogen; growth on N
2
was most rapid at a pO
2
of 0.005 to 0.007 atm. Numbers of
S. lipoferum
can be estimated by diluting soil, crushed roots, or other material, and inoculating diluted samples into a stagnant semisolid medium. Development of a characteristic subsurface layer of organisms and demonstration the these organisms can reduce C
2
H
2
are presumptive evidence that they are
S. lipoferum.
With most-probable-number tables the observations can be converted to numbers of
S. lipoferum
in the samples. The most-probable-number method indicated that numbers of
S. lipoferum
may increase 100-fold or more in roots of maize removed from the plant and incubated for 24 h at 30°C at a pO
2
initially adjusted to 0.01 atm.
Aerobic microbial flora of intertrigenous skin
Authors: Aly R , Maibach H I
Published: January 2020

The incidence and density of intertrigenous microflora were determined in subjects using nonmedicated soap. The axilla, groin, toe web, and finger web were examined. The incidence of gram-negative rods was 17% for the axilla, 13% for the groin, 10% for the toe web, and 9% for the finger web. Klebsiella, Proteus, and Enterobacter were the predominant organisms, in that order. The highest incidence of Staphylococcus aureus was in the groin (12%) and toe web (11%). Lipophilic diphtheroids were the most prevalent bacteria in the groin (1.1 X 10(6)/cm2) and toe web (1.2 X 10(6)/cm2). Nonlipophilic diphtheroids were the predominant flora in the axilla (1.3 X 10(7)/cm. Micrococci had the highest counts in the toe web (7.6 X 10(5)/cm2). The incidence of coagulase-negative staphylococci was highest in the finger web, but the major flora were those of micrococci.
Improved Enumeration of
Streptomyces
spp. on a Starch Casein Salt Medium
Authors: Mackay Shirley J.
Published: January 2020

Well-formed
Streptomyces
colonies were counted more rapidly when a starch casein medium containing antibiotics was supplemented with either magnesium chloride or additional sodium chloride.
Procedures involving lipid media for detection of bacterial contamination in breweries
Authors: Van Vuuren H J , Louw H A , Loos M A , Meisel R
Published: January 2020

The liquid equivalent of universal beer agar, designated universal beer liquid medium, and its beer-free equivalent, universal liquid medium (UL), were equally effective in demonstrating bacterial contamination in 120 of 200 samples from different stages of commercial brewing process. Growth of the contaminants after 3 days was consistently more luxuriant in the UL medium. A yeast-water substrate medium failed to reveal many contaminants detected with UL in 392 samples from three breweries and revealed only a few not detected with UL. The use of UL and a lactose-peptone medium, with microscope examination of the media for bacterial growth, permitted detection of 93% of the known contaminants compared to 87%, detected with UL alone; this combination or universal beer liquid medium plus lactose-peptone medium can therefore be recommended for the detection of bacterial contaminants in brewery samples. Bacterial contamination of pitching yeasts appeared to be a particular problem in the breweries investigated.
Study of conditions of production of roquefortine and other metabolites of Penicillin roqueforti
Authors: Scott P M , Kennedy B P , Harwig J , Blanchfield B J
Published: January 2020

Experiments to determine optimum yields of roquefortine, isofumigaclavine A, and PR toxin, metabolites from Penicillum roqueforti Thom, were performed. Four strains, isolated from blue cheese, and five liquid media were evaluated, although not all permutations were studied. Sucrose (15%)-yeast extract (2%) was the medium chosen for time-course studies at 25 and 15 degrees C using one favorable strain. At 25 degrees C, maximum estimated yields of roquefortine were about 100 mg/liter in the mycelium by 16 days, and no subsequent degradation of this alkaloid was observed. On the other hand, production of PR toxin in the medium peaked at 770 mg/liter at 21 days. At 15 degrees C, yields of roquefortine and PR toxin after 49 days were 60 to 70% of the maximum yields obtained at 25 degrees C. However, about three times more isofumigaclavine A (up to 11 mg/liter) was formed in the mycelium at 15 degrees C than at 25 degrees C. All four strains of P. roqueforti procedure both roquefortine and PR toxin on the sucrose-yeast extract medium at 25 degrees C; isofumigaclavine A was detected in all but one strain grown on this medium.
Effect of culture conditions on synthesis of L-asparaginase by Escherichia coli A-1
Authors: Barnes W R , Dorn G L , Vela G R
Published: January 2020

The nutritional requirements and culture conditions affecting biosynthesis of L-asparaginase in a mutant of Escherichia coli HAP designated strain A-1 were studied. Asparaginase activity was increased by the addition of L-glutamic acid, L-glutamine, or commercial-grade monosodium glutamate. The rate of enzyme synthesis was dependent on the interaction between the pH of the culture and the amount of oxygen dissolved in the medium. A critical oxygen transfer rate essential for asparaginase formation was identified, and a fermentation procedure is described in which enzyme synthesis is controlled by aeration rate. Enhancement of L-asparaginase activity by monosodium glutamate was inhibited by the presence of glucose, culture pH, chloramphenicol, and oxygen dissolved in the fermentation medium.
Fermentation of cellulose and cellobiose by Clostridium thermocellum in the absence of Methanobacterium thermoautotrophicum
Authors: Weimer P J , Zeikus J G
Published: January 2020

The fermentation of cellulose and cellobiose by Clostridium thermocellum monocultures and C. thermocellum/Methanobacterium thermoautotrophicum cocultures was studied. All cultures were grown under anaerobic conditions in batch culture at 60 degrees C. When grown on cellulose, the coculture exhibited a shorter lag before initiation and growth and celluloysis than did the monoculture. Cellulase activity appeared earlier in the coculture than in the monoculture; however, after growth had ceased, cellulase activity was greater in the monoculture. Monocultures produced primarily ethanol, acetic acid, H2 and CO2. Cocultures produced more H2 and acetic acid and less ethanol than did the monoculture. In the coculture, conversion of H2 to methane was usually complete, and most of the methane produced was derived from CO2 reduction rather than from acetate conversion. Agents of fermentation stoppage were found to be low pH and high concentrations of ethanol in the monoculture and low pH in the coculture. Fermentation of cellobiose was more rapid than that of cellulose. In cellobiose medium, the methanogen caused only slight changes in the fermentation balance of the Clostridium, and free H2 was produced.
Isolation and identification of xanthomegnin, viomellein, rubrosulphin, and viopurpurin as metabolites of penicillium viridicatum
Authors: Stack M E , Eppley R M , Dreifuss P A , Pohland A E
Published: January 2020

Four of the metabolites of Penicillium viridicatum 66-68-2 grown on rice cultures were isolated and identified as xanthomegnin, viomellein, rubrosulphin, and viopurpurin. Melting points, elemental analysis, and infrared, ultraviolet, and field desorption and electron impact mass spectra of the isolated compounds were consistent with values reported in the literature for these compounds. In addition, diacetate and triacetate derivatives were prepared, and the chemical and physical analyses of the derivatives were also consistent with literature data. Proton magnetic resonance spectroscopy and thin-layer chromatography were also used for the additional identification of selected compounds.
Degradation of malathion by salt-marsh microorganisms
Authors: Bourquin A W
Published: January 2020

Numerous bacteria from a salt-marsh environment are capable of degrading malathion, an organophosphate insecticide, when supplied with additional nutrients as energy and carbon sources. Seven isolates exhibited ability (48 to 90%) to degrade malathion as a sole carbon source. Gas and thin-layer chromatography and infrared spectroscopy confirmed malathion to be degraded via malathion-monocarboxylic acid to the dicarboxylic acid and then to various phosphothionates. These techniques also identified desmethyl-malathion, phosphorthionates, and four-carbon dicarboxylic acids as degradation products formed as a result of phosphatase activity.
Occurrence of human-associated yeasts in bivalve shellfish from Long Island Sound
Authors: Buck J D , Bubucis P M , Combs T J
Published: January 2020

Candida parapsilosis, C. tropicalis, and Torulopsis glabrata were the human-associated yeasts most frequently isolated from quahogs, oysters, and mussels collected from four estuarine areas along the northern shore of Long Island Sound. Some inconsistency and seasonal variation in the occurrence of these and other yeast species were noted. In particular, C. albicans densities were greatest during colder months in the more heavily polluted waters. A total of 347 yeasts were isolated and cultured at 37 degrees C and, of these, 219 of 62% were human-associated forms. Generally, these yeasts in the animals sampled reflected the overall pollution status of the estuary from which they were taken. This study represents a clear demonstration of potentially pathogenic yeasts in a valuable marine resource.