bluuebunny/crossref_metadata_2025 huggingface dataset:
Requirement for salts for the isolation of lipopolysaccharide from a marine pseudomonad
Authors: O'Leary Gerard P. , Nelson Jr. John D. , MacLeod Robert A.
Published: February 2010

When cells of a marine pseudomonad (ATCC 19855) were extracted with 45% aqueous phenol, lipopolysaccharide (LPS) could not be recovered from the extract. If the phenol solution used for extraction contained NaCl, KCl, and MgCl2 at their concentrations in the growth medium (0.22 M, 0.01 M, and 0.026 M respectively) and the fluid used subsequently to dialyze the extract free of phenol was a solution of the same salts, LPS could be sedimented from the aqueous phase of the extract by centrifugation at 144 000 × g. Tests on the individual salts at their growth-medium concentrations showed that the presence of MgCl2 alone in the phenol solution gave rise to even higher yields of LPS than did the three salts together. With NaCl in the phenol solution, the yield of LPS was much reduced while with KCl present, either traces or no LPS could be isolated. Qualitative and quantitative analysis of the LPS showed galactose and glucose to be the predominating neutral sugars, and glucosamine and galactosamine the major amino sugars. Two unidentified amino sugars were present in small amounts. They were tentatively identified as a 2-amino sugar with chromatographic characteristics similar to 2-aminoquinovose and a 4-amino sugar. The LPS contained 1.25% heptose sugar, 0.1% 2-keto-3-deoxyoctulosonic acid (KDO), and 12.9% lipid A.
Cell-fusion properties of Sendai virus prepared by polyethylene-glycol precipitation
Authors: Cook Gregory J. , Babiuk Lorne A. , Hudson James B.
Published: February 2010

Sendai virus was concentrated from the allantoic fluid of embryonated chicken eggs by polyethyleneglycol (PEG) precipitation. A concentration of 6–8% PEG sufficed to precipitate essentially all of the virus (measured by hemagglutination) with maximum retention of cell-fusion ability. Electron-microscopic examination of the 6% PEG pellet revealed only intact virions. Thus the method is suitable for preparing Sendai virus for cell-fusion experiments.
Purification and properties of mycoferritin from Mortierella alpina
Authors: Bozarth R. F. , Goenaga A.
Published: February 2010

A culture of Mortierella alpina Peyroud isolated from soil and grown on Czapek-Dox medium was found to contain a high concentration of mycoferritin (MF). The MF was extracted from lyophilized mycelium by grinding with 0.1 M, pH 7.0, potassium-phosphate buffer and chloroform followed by differential centrifugation. Sucrose density-gradient centrifugation of the concentrated MF resulted in a brownish-yellow band in the region of 60–70 S. Following dialysis and concentration by high-speed centrifugation, the MF was compared to horse-spleen ferritin (HF). The ultraviolet (uv.) and infrared (i.r.) spectra of MF and HF were identical. Negatively stained preparations examined in the electron microscope showed particles of about 10 nm diameter. Sedimentation rates of S20,w = 66 for MF and S20,w = 56 for HF were obtained by analytical ultracentrifugation. The MF preparation contained 83% protein and 17% iron. The molecular weight of the protein subunit was determined by gel electrophoresis to be about 19 300 daltons.
Coccal cell-wall compactness and the swelling action of denaturants
Authors: Ou Li-Tse , Marquis Robert E.
Published: February 2010

Isolated cell walls of Micrococcus lysodeikticus and Staphylococcus aureus were found to have relatively low densities in both the dried and hydrated states. Thus, it appears that the component polymers of these structures do not form crystallites or other highly condensed assemblies, but rather, that their distribution within the wall matrix is similar to that of the polymer chains in low-density, ion-exchange resins. Micrococcus lysodeikticus walls, which are composed mainly of peptidoglycan, swelled significantly when they were heated or transferred to 8 M urea solution. This finding suggests that the compactness of walls and their component peptidoglycans is determined in part by weak interactions that can be disrupted by urea or by heat.
Influence of the age of mycobacterial cultures on the protein and carbohydrate composition of tuberculins
Authors: Turcotte R. , Ormeaux Y. Des
Published: February 2010

Significant variations in the protein and carbohydrate contents of bacterial cells and of mycobacterial fractions occurred during the growth cycle of three strains of Mycobacteria (H37Rv, H37Ra, and BCG).In whole bacilli or their water-soluble extracts, a peak of proteins occurred early during the exponential phase of growth, whereas polysaccharides reached a maximum 2 to 3 weeks later. In culture filtrates, the amount of both proteins and carbohydrates increased with the aging of tubercle bacilli; the increase of carbohydrates, however, was larger. Few quantitative differences in the yield and chemical composition of mycobacterial fractions were noted between the three tubercle bacilli.
Dose-dependent viremia and the differential immunoglobulin response of hamsters to Powassan virus
Authors: Chernesky Max A. , Whittaker-Haines Patricia J.
Published: February 2010

Hamsters injected subcutaneously with a single "low-dose" inoculum (10 mouse LD50) of Powassan virus developed viremia titering 106.2 mouse LD50 per milliliter of blood whereas hamsters receiving a "high-dose" inoculum of 105.0 mouse LD50 of virus developed a viremia of only 104.5 mouse LD50 per milliliter.Hemagglutination-inhibiting (HI) antibodies were first detected 7 days following the "low-dose" inoculation and attained maximum titers of 160. The HI antibody response to the "high-dose" virus inoculation began on the 5th day, at a time when viremia was present, and antibody titers did not exceed 40. Sucrose-density analysis and 2-mercaptoethanol treatment of sera revealed that IgM antibodies were induced by both inocula but animals receiving a low dose of virus produced higher IgG responses than did animals receiving a high dose of virus. Neutralizing antibodies, which did not appear until 30 days post inoculation, were present at a log neutralizing index (NI) of 2.0 at 60 days in animals receiving 10 mouse LD50 of virus and at a log NI of 1.0 in those receiving 105.0 mouse LD50. The NI of IgG was equal to the index for total gamma globulin in samples that contained both IgM and IgG as demonstrated by the HI test.Animals originally exposed to a "low-dose" inoculum produced a more prolonged anamnestic response when challenged 63 days later with 105.0 mouse LD50 of virus than did animals receiving a second inoculum containing only 103.0 or 10 mouse LD50 of virus. In contrast, poor secondary antibody responses were elicited by challenge doses of 105.0, 103.0, or 10 mouse LD50 of virus in animals that originally had received a "high-dose" of virus. IgM and IgG classes of antibody were induced in all secondary responses and the log NI of each group of animals was elevated by about 1 during anamnesis.
Somatic nuclear division in the sporidia of Ustilago violacea. I. Acetic orcein staining
Authors: Day Alan W. , Jones John K.
Published: February 2010

The course of somatic nuclear division was investigated in randomly and synchronously dividing populations of Ustilago violacea. Interphase nuclei with diffuse chromatin are found in the sporidia just before budding, but distinct chromatin granules form at the onset of bud formation. These granules become more condensed and appear to be connected by lightly staining fibers. When the bud cell reaches about half the size of the parent cell, the granules aggregate into two parallel 'bars' or 'tracks' of chromatin. This double structure migrates towards the isthmus between parent cell and bud cell and passes through completely, leaving the parent cell enucleate. The nucleus in the bud cell becomes highly condensed and is composed of two lobes which separate from each other to form two daughter nuclei in the bud cell. One nucleus returns to the parent cell and immediately enters interphase, while the other is retained in the bud cell in telophase. The nucleus in the bud cell remains in telophase until the cell reaches the full size of a parent cell, when it then enters interphase. Counts of the chromatin granules before the formation of the 'double-bar' stage show that the number of visible elements may be as many as 20 in both haploid and diploid strains, and it is suggested that previous claims that n = 2 in U. violacea are based on misinterpretation of aggregates of chromosomes. The similarity in the number of visible elements in haploid and diploid strains is considered to be a result of somatic association of homologous chromosomes in the diploid strain.
The effects of griseofulvin on mitosis in Aspergillus nidulans
Authors: Crackower S. H. B.
Published: February 2010

The effects of the antifungal agent, griseofulvin, on mitosis in a diploid strain of Aspergillus nidulans has been studied. Helly-fixed preparations stained with acid fuchsin normally reveal densely staining, spherical nucleoli, lateral granules accompanying the nucleoli, and spindles in various stages of development. The development of this granule results in the formation of a small cigar-shaped spindle which increases in size in later stages of division and then becomes stretched out into a thin, long fiber at the termination of division.Cultures treated with griseofulvin reveal damaged and distorted spindles within 30 s to 1 min after treatment. After 1 min or more of drug treatment, no normal spindles are seen but granules forming the polar regions of the spindle persist.The division of the chromatin during mitosis is also distorted by griseofulvin treatment. Cultures treated with this drug reveal abnormal chromatin configurations after 15–20 min. Individual chromosomes such as those seen at metaphase-like stages become distorted into a dense mass of chromatin. The further stages of division reveal abnormally stretched out lengths of chromatin which are, however, capable of division by a break in the constricted thread near the center.Spindles appear to recover from the griseofulvin treatment when treated cultures are transferred to fresh medium not containing griseofulvin at 35 °C for 90 min.
Analysis of temperature-sensitive sporulation mutants of Bacillus subtilis by transduction
Authors: Rogolsky Marvin
Published: February 2010

The results derived from two- and three-factor PBS-1 mediated transduction crosses established that five separate temperature-sensitive sporulation mutations of Bacillus subtilis were located between the ura-1 and spoC-6NG markers.
Mitosis in Cladosporium herbarum
Authors: Crackower S. H. B.
Published: February 2010

Using cytological techniques which have been established in previously published studies of mitosis in fungi, a similar study was undertaken with the ubiquitous mold, Cladosporium herbarum. The preparations obtained revealed both similarities and differences to studies of other closely related organisms.
Acid and alkaline phosphatases in Schizophyllum commune
Authors: Wilson Ronald W.
Published: February 2010

Several properties of the acid and alkaline phosphatases of Schizophyllum commune were investigated during various stages of morphogenesis.
Numbers and antagonistic properties of bacteria from buds of field-grown soybean plants
Authors: Chakravarti B. P. , Leben Curt , Daft G. C.
Published: February 2010

Bacteria were isolated from terminal buds of field-grown soybean plants during two growing seasons. Most buds yielded 106–107 bacteria/g (wet weight). A variety of cultural types was noted. Some isolates were antagonistic in vitro to Pseudomonas glycinea and other bacterial pathogens.
Isolation of carbohydrate-metabolizing, extremely halophilic bacteria
Authors: Tomlinson Geraldine A. , Hochstein Lawrence I.
Published: February 2010

Four previously unrecognized strains of extremely halophilic bacteria that utilize carbohydrates have been isolated. Gas production proved an unreliable index of carbohydrate metabolism; therefore, carbohydrate utilization was measured by determining acid formation and sugar disappearance during growth. By these procedures, carbohydrate utilization was readily detected. The results suggest that carbohydrate dissimilation by extremely halophilic bacteria may be more common than previously thought and that the apparent rarity of carbohydrate-metabolizing halophiles may be an artifact of the isolation procedures used.
Bacteriocins of the phytopathogens Pseudomonas syringae, P. glycinea, and P. phaseolicola
Authors: Vidaver Anne K. , Mathys Mary L. , Thomas Mary E. , Schuster Max L.
Published: February 2010

Pseudomonas syringae, P. phaseolicola, and P. glycinea produced and were sensitive to bacteriocins. Both solid and liquid media were used in the detection procedures. The bacteriocins were classified into 11 groups on the basis of activity spectra against strains of the same species, related and unrelated species, and unrelated genera. Heat, chloroform, trypsin, and pronase sensitivity were useful in subdividing some of the groups. All P. syringae strains produced bacteriocins, as did 55% of the P. glycinea strains and 8% of the P. phaseolicola strains.Bacteriocins from P. syringae had the broadest spectrum of activity, those from P. glycinea were more restricted in activity, and those from P. phaseolicola had the narrowest range of activity.Bacteriocin production was affected by agar depth, age of plates, age of culture, colony type, amount of inoculum, proximity to producers of bacteriocin inhibitors, and temperature. In many cases, detection of bacteriocin production depended on the choice of these conditions.
California encephalitis virus: serological evidence of human infections in Alaska
Authors: Feltz Elmer T. , List-Young Betty , Ritter Donald G. , Holden Preston , Noble Gary R. , Clark Paul S.
Published: February 2010

Thirty percent of 325 sera from Athapaskan Indians in five villages in east-central Alaska were found to be positive for antibodies of California encephalitis virus (CEV) by means of the hemagglutination-inhibition (HI) test, using CEV prototype strain 283 for hemagglutination (HA) preparation. Neutralizing antibodies were detected in 72% of the sera by means of a plaque reduction method, using CEV Jamestown Canyon strain 2235. In these tests, CEV-neutralizing substances were present in all but 1 of 94 persons tested over age 30. The serum of the single exceptional individual was positive in the HI test. Since most of the persons tested had not traveled outside Alaska, serological evidence indicates that exposure to CEV had occurred within the state. Evidence for the occurrence of arboviruses in Alaska has not been reported previously.
Distribution of Clostridium botulinum type E in the Gulf of St. Lawrence in relation to the physical environment
Authors: Laycock R. A. , Loring D. H.
Published: February 2010

Analysis of 390 sediment samples from the Gulf of St. Lawrence and the lower reaches of the St. Lawrence River showed C. botulinum type E to be present in high incidence in some areas while it appeared to be absent from others. No other types of C. botulinum were encountered. The observed distribution of type E could be correlated with patterns of terrigenous sedimentation in the region.
Oxidation of manganous salts of manganese by soil fungi
Authors: Timonin M. I. , Illman W. I. , Hartgerink T.
Published: February 2010

The microbiological analysis of soils from Ontario, Yukon, and Northwest Territories showed the presence of manganese-oxidizing bacteria, Actinomycetes, and fungi. Bacteria and Actinomycetes were predominant in boreal and tundra soils whereas fungi were predominant in the Ontario samples. The 18 species of fungi studied were able to oxidize 10 different compounds of manganese including a chelated form as well as an organic Mn2+ complex. Coniothyrium fuckelii, Periconia sp., P. circinata, P. macrospinosa, Phoma sp., and Sporothrix sp. oxidized all 10 Mn2+ compounds tested. One bacterial culture isolated from Arctic soil was able to oxidize only Mn2+ acetate and tartrate salts.The addition to Mn2+ sulfate medium of either calcium salts of several organic acids or various carbohydrates affected the growth of fungi as well as the nature of the end product of Mn2+ oxidation. Thus, the manganic granules produced by Cephalosporium sp. in the medium in the presence of glucose or starch were resistant to solubilization, dissolving only after 6 h in 1 N ammonium acetate (pH 7.0) containing 0.2% of hydroquinone. Granules produced by P. circinata in the presence of cellulose were insoluble in this solvent. On dissolution of the granules with 30% hydrochloric acid, the residue did not show the presence of bacteria under microscopic examination.
Pyruvate kinase of Neurospora crassa: purification and some properties
Authors: Kapoor M. , Tronsgaard T. M.
Published: February 2010

Pyruvate kinase of Neurospora crassa has been purified and some of its properties are reported. The procedure used for purification consists of five steps yielding a 90 to 95% purified protein. Preliminary sedimentation analysis yielded a sedimentation coefficient of 9.5 for this enzyme. Maximal stabilization of the enzyme is achieved in phosphate buffer; Tris buffer induces a conformational change in the enzyme leading to inactivation. Inactivation can be reversed by incubation with substrates, PEP and ADP. Preliminary kinetics studies suggest the formation of a ternary complex rather than a Ping Pong type of a mechanism.
Catalase activity and nitrogen fixation in legume root nodules
Authors: Francis A. J. , Alexander Martin
Published: February 2010

Effective white clover and soybean nodules contained more catalase than ineffective nodules. The catalase activity of a Rhizobium japonicum strain collected from effective soybean nodules was greater than that in a strain from the ineffective root structures. Ineffective Rhizobium trifolii mutants grown in laboratory media had less catalase than their effective parent strains, but no relationship between catalase content and effectiveness was noted among laboratory-grown R. japonicum cultures. Effective nodules from soybean but not from white clover were somewhat richer in peroxidase than the analogous non-nitrogen-fixing root structures. No correlation was evident between effectiveness and phenol-oxidase activity of soybean nodules.
Intracellular replication of infectious pancreatic necrosis virus
Authors: Argot Jeanne , Malsberger R. G.
Published: February 2010

Deoxyribonucleic acid (DNA) synthesis was repressed in cells 4 h after infection with infectious pancreatic necrosis (IPN) virus as determined by scintillation counting. Ribonucleic acid (RNA) synthesis was stimulated beginning 4 to 5 h after infection and reached a peak at 6 h. No Feulgen-positive viral inclusions were observed and the occasional inclusions seen exhibited green fluorescence when stained with acridine orange. These results suggest that the nucleic acid of IPN is double-stranded RNA.
Lysosomes and the "toxicity" of Rickettsials. II. Non-cytocidal interactions of egg-grown C. psittaci 6BC and in vitro macrophages
Authors: Kordová Nonna , Poffenroth Linda , Wilt John C.
Published: February 2010

During the infection of cultured mouse peritoneal phagocytes with egg-grown C. psittaci 6BC strain, lysosomes retained their integrity and host cells were not damaged. Infected monocytes showed greater ability than uninfected monocytes to spread and transform into giant cells containing enlarged nuclei and masses of cytoplasm with clear cytoplasmic vacuoles. Chlamydial particles were released from the cytoplasm of infected phagocytes by pseudopodia-like extrusions. These events were in marked contrast to the effect of L cell grown C. psittaci 6BC strain which caused early leakage of lysosomal acid phosphatase into the cytoplasm of macrophages and induced a rapidly progressive irreversible cell damage (14).
Alpha-ketoglutarate as an intermediate in glutamate metabolism by Peptococcus aerogenes
Authors: Johnson W. M. , Westlake D. W. S.
Published: February 2010

The pathway from glutamic acid to α-hydroxyglutaric acid in Peptococcus aerogenes proceeds via α-ketoglutaric acid and is mediated by two NAD-dependent enzymes. One enzyme, an NAD-dependent glutamic acid dehydrogenase, oxidatively deaminates glutamic acid to α-ketoglutaric acid. The other enzyme, α-ketoglutaric acid reductase, reduces α-ketoglutaric acid to α-hydroxyglutaric acid in the presence of NADH. The demonstration of a very low level of α-ketoglutaric acid dehydrogenase activity in crude cell-free extracts indicates that the primary metabolic pathway for glutamic acid carbons proceeds via α-hydroxyglutaric acid and not via the TCA cycle. Potential energy-yielding mechanisms are discussed relative to the known specific distribution of glutamic acid carbon atoms in fermentation products.
Importance of pear-tissue injury to infection by Erwinia amylovora and control with streptomycin
Authors: Zwet T. van der , Keil H. L.
Published: February 2010

Greenhouse, orchard, and laboratory experiments have shown the significance of pear shoot and fruit injury to infection by Erwinia amylovora. Bartlett trees injured by sand blasting and then spray-inoculated in the greenhouse were infected predominantly through leaf petioles. Blight development was more severe when inoculated trees were incubated in the moist chamber than on the greenhouse bench and when inoculated within 24 h after injury than after longer time intervals. Streptomycin provided satisfactory blight control of injured trees when applied within 6 h after inoculation, while uninjured trees were protected for 4 days. Excellent control was obtained when streptomycin was applied within 24 h after injury and inoculation, when preceded by a protective streptomycin spray. All injured Bartlett fruit on orchard trees dipped in E. amylovora inoculum at time of wounding blighted, while 70% of those bruised 2 days before or after inoculation became infected, regardless of streptomycin application. Dip-inoculated, streptomycin-treated fruit bruised with breakage of the skin showed 5 times more blighted fruit than when the skin remained unbroken. Orchard observations on four pear cultivars under severe blight conditions revealed that 62% of the trees exhibited both shoot and fruit blight, 8% only shoot blight, and 17% only fruit blight. Moonglow cultivar was the most resistant to fire blight and showed the lowest percent infected fruit. In the laboratory, punctured and inoculated fruit of all cultivars blighted but uninjured DeVoe fruit did not blight regardless of inoculum concentration.
Dimorphism in a new isolate of Saccharomycopsis Schiönning
Authors: Buecher Edward J. , Phaff Herman J.
Published: February 2010

Two strains of Saccharomycopsis guttulata Robin (Schiönning) were isolated from two out of four specimens of Lepus californicus, the wild jack rabbit of California. One isolate was similar to typical strains with budding cells occurring in domestic rabbits. The second strain was atypical in being dimorphic. Colonies of the yeast form, consisting of budding cells, were smooth and glistening, while those of the filamentous form were irregular, rough, and dull. The filamentous form consisted of septate, branched hyphae, radiating from a central origin of growth. New filaments generally were initiated by fragmentation. The two new strains were similar to domestic strains in assimilation and fermentation reactions and grew only between 30 and 40C. Both strains formed ascospores at 18C. The filamentous strain, unlike other S. guttulata strains, was not carbon dioxide dependent at 37C but did require oxygen. At 30C it became carbon dioxide dependent. During the stationary phase, a morphogenetic change occurred from the filamentous form to a yeast form, which was stimulated by anaerobic conditions. The budding form of the filamentous strain was relatively stable in culture and at either 30 or 37C it was carbon dioxide dependent. Spontaneous reversions from the budding to the filamentous form appear to occur sporadically.
Sensitivity of normal and mutant strains of Escherichia coli to actinomycin-D
Authors: Singh A. P. , Cheng K.-J. , Costerton J. W. , Idziak E. S. , Ingram J. M.
Published: February 2010

The site of the cell barrier to actinomycin-D uptake was studied using a wild-type Escherichia coli strain P and its cell envelope-defective filamentous mutants, strains 6γ and 12γ, both of which 'leak' β-galactosidase and alkaline phosphatase into the medium during growth indicating both membrane and cell-wall defects. Actinomycin-D entered the cells of these two mutant strains as evidenced by the inhibition of both 14C-uracil incorporation and synthesis of the induced β-galactosidase system. Under similar conditions, no inhibition occurred in the wild-type strain and its sucrose-lysozyme prepared spheroplasts. Actinomycin-D did, however, inhibit the above-mentioned systems in the wild-type sucrose-lysozyme spheroplasts prepared in the presence of 2 mM EDTA. The experimental data indicate that although the cell wall may act as a primary barrier or sieve to actinomycin-D, the cytoplasmic membrane should be considered the final and determinative barrier to this antibiotic.
Susceptibility of the Mongolian gerbil (Meriones unguiculatus) to Western equine encephalitis
Authors: Hayles L. B.
Published: February 2010

The Mongolian gerbil (Meriones unguiculatus) was highly susceptible to peripheral infection with Western equine encephalitis virus. Small doses of virus ranging from 0.1 to 10 intracerebral 3-week-old mouse LD50 which induced no clinical response in 3-week-old mice when inoculated subcutaneously, caused death in 4-week-old gerbils. At this age, a standard dose of virus produced uniform viremia patterns between individuals. Peak virus concentration approaching 105.0 intracerebral 3-week-old mouse LD50 per 0.03 milliliter of blood, was attained at 48 h post inoculation. Resistance to infection increased with age but 10-week old gerbils remained susceptible and exhibited marked clinical signs of encephalitis during the course of infection. Brains from animals, which died within 10 days of infection, yielded large amounts of virus.
The effect of thioglycolic acid or propanol pretreatment on lysing of Streptococcus lactis with lysozyme and salt
Authors: Hurst A. , Kruse H.
Published: February 2010

Attempts were made to increase the sensitivity of cells of Streptococcus lactis to lysis by lysozyme and salt. Cells were pretreated by incubation with thioglycolic acid or extracted with propanol. The two pretreatments had the same effect: these cells bound more lysozyme more firmly than untreated cells. The pretreatments abolished a Mg2+ effect and solubilized acidic proteins without affecting the degree of lysis caused by lysozyme and salt.
Protein synthesis during fungal-spore germination. VI. Analysis of transfer ribonucleic acid from germinated and ungerminated spores of Rhizopus stolonifer
Authors: Merlo Donald J. , Roker Henry , Van Etten James L.
Published: February 2010

Aminoacyl-tRNA's were prepared using the tRNA and enzyme fractions from ungerminated and germinated spores of Rhizopus stolonifer. No significant differences between ungerminated and germinated tRNA fractions were detected for 7 of the 10 amino acids analyzed by cochromatography on benzoylated-diethylaminoethyl cellulose columns. Quantitative changes in one of the two isoaccepting species of lysyl-tRNA and of valyl-tRNA were observed, whereas a qualitative alteration in isoleucyl-tRNA occurred during germination.
Inhibition of fungal growth and sporulation by volatile metabolites from bacteria
Authors: Moore-Landecker Elizabeth , Stotzky G.
Published: February 2010

Volatile metabolites produced by eight bacterial species greatly inhibited growth and sporulation of all fungi tested, namely Fusarium oxysporum f. conglutinans, Gelasinospora cerealis, Penicillium viridicatum, Trichoderma viride, and Zygorhynchus vuilleminii. Alterations of colony morphology were induced in all test fungi, except G. cerealis. In P. viridicatum, colony contour and color were altered; in F. oxysporum f. conglutinans, T. viride, and Z. vuilleminii, the amount or distribution of aerial growth was altered.
Characterization of a mucoid Escherichia coli K12 strain, and chemical analysis of the exopolysaccharide
Authors: Shugar Stephen , Sanderson Kenneth E.
Published: February 2010

A spontaneous mutant of Escherichia coli K12 C600 was isolated which is mucoid as a result of overproduction of an extracellular polysaccharide. This strain also forms filaments, is sensitive to ultraviolet irradiation, and has its genetic lesion closely linked to the lac gene. Its phenotype and map position are analogous to the lon mutation (long form). The exopolysaccharide contains fucose, glucose, galactose, and may contain glucuronic acid, but the molar ratios of these sugars differ from those previously reported.
The effect of temperature on spore germination and growth of Mucor miehei in submerged culture
Authors: Streets B. W. , Ingle M. B.
Published: February 2010

Mucor miehei was grown in submerged culture at 30, 37, 40, 42.5, 45, and 48 °C. Maximum growth yield occurred at 48 °C.The effect of temperature on spore germination was examined. No spores germinated within 8 h at temperatures below 36.7 °C or above 53.5 °C. The optimum temperature for spore germination was 45 °C.Growth occurred at the marginal temperatures of 20 °C and 25 °C only when the spores were pre-germinated at 37 °C
Photoreactivation in Halobacterium cutirubrum
Authors: Hescox M. A. , Carlberg D. M.
Published: February 2010

Extremely halophilic bacteria are able to survive in a natural environment exposed to high doses of ultraviolet irradiation. One such organism, Halobacterium cutirubrum, has been characterized to possess an extremely efficient photoreactivation from ultraviolet damage. A population irradiated to 1% survivors can photoreactivate to complete recovery of the original population in less than 1 h of illumination. Inhibition of carotenoid pigments by 10−6 M diphenylamine decreased photoreactivation efficiency. The carotene pigments have been implicated in an energy-transfer role to augment the photoreactivation mechanism
Further observations on the mode of action of the alpha toxin of Staphylococcus aureus "Wood-46"
Authors: Wiseman G. M. , Caird J. D.
Published: February 2010

Further evidence has been obtained which supports the view that alpha toxin from Staphylococcus aureus "Wood 46" is a protease which requires activation by erythrocyte membrane proteases. Rabbit erythrocyte antiprotease prepared in mice inhibited degradation of rabbit ghosts by the toxin. Supernatant fluid of toxin-treated ghosts incubated with EDTA and then passed through a column of Sephadex G-75 yielded a fraction which was hemolytic and proteolytic. These activities were both neutralized by alpha antitoxin prepared in rabbits, but not by control sera.It was also observed that alpha antitoxin inhibited the proteolytic activity of rabbit ghosts not exposed to toxin, in contrast with control sera. Inhibitory ability was removed from the antitoxin by adsorption with a heavy suspension of ghosts, and this treatment destroyed the antitoxin's capacity to neutralize hemolytic activity of the alpha toxin.
Satellite deoxyribonucleic acid in Pseudomonas aeruginosa
Authors: Finley Ruth B. , Punch J. D.
Published: February 2010

Deoxyribonucleic acid preparations from two strains of Pseudomonas aeruginosa newly isolated from clinical specimens each contained double-stranded satellite DNA. The satellite DNA in one strain consisted of two components with buoyant densities of 1.705 and 1.712 g cm−3 and comprised 28% of the total extracted DNA. The other strain contained 15% satellite DNA which was composed of components with buoyant densities of 1.711 and 1.718 g cm−3.
Soil enrichment for the isolation of sporangial subgroup II Bacillus species, and observations concerning a coil-forming member of this group
Authors: Wood R. T. , Casida Jr. L. E.
Published: February 2010

Enrichment culture procedures are described which allow recovery from soil of mainly sporangial subgroup II Bacillus species, subgroup I plus subgroup II, or the latter plus a coil-forming member of subgroup II. After isolation, the coil-forming type grew normally and sporulated extensively only on agarized soil medium. Growth was normal on soil extract agar but sporulation was less extensive. Limited sporulation occurred when divalent cations were added to more conventional media. Normal vegetative growth occurred on other media investigated only when the pH value was held within relatively narrow limits. The presence of carbohydrate in agar media caused partial growth inhibition, a lack of catalase activity, and the formation of very long coiled cells plus pleomorphic cells, whereas overt cell lysis occurred in vigorously shaken broth cultures. These responses possibly reflect an unbalanced growth condition caused by growth at pH extremes, and not by carbohydrate per se. The characteristic features that set the coil-forming bacilli apart from other subgroup II Bacillus species were shown to be (1) their inability to grow at pH values below 6.5, (2) their inability to ferment carbohydrates, (3) their high oxygen requirement for growth, and (4) their ability to reduce thiosulfate to H2S. In addition, these bacilli can be distinguished from closely related established species by other biochemical tests.
Lysine control of penicillin biosynthesis
Authors: Masurekar Prakash S. , Demain Arnold L.
Published: February 2010

The known diminution in penicillin formation by added lysine is thought to occur via feedback regulation of the lysine biosynthetic pathway, thus depleting the cells of α-aminoadipic acid, a precursor of penicillin. Studies were conducted to determine whether feedback repression or inhibition is the key mechanism involved. Lysine at 20 mM prevented net penicillin formation by starved mycelia of Penicillium chrysogenum Wis. Q-176 and Wis. 54-1255 until the extracellular lysine concentration fell by 90%. Growth in lysine did not reduce incorporation of L-valine-U-14C into penicillin by washed suspensions of either strain. On the other hand, the presence of lysine in the suspension system did lower valine incorporation. The data show that lysine acts by inhibition of enzyme action rather than by repression of enzyme synthesis.
Effects of cholesterol on growth and lipid composition of Pythium sp. PRL 2142
Authors: Brushaber J. A. , Child J. J. , Haskins R. H.
Published: February 2010

Addition of exogenous cholesterol to Pythium initially increases the growth rate, but the final dry weight yield is reduced. Cholesterol induces an overall increase in lipid synthesis after the initial period of rapid growth. The lipid content of cholesterol-grown mycelium becomes about double that of mycelium grown without cholesterol. The proportion of phosphatidyl serine relative to other phospholipids is reduced by half in mycelia grown with cholesterol. The major phospholipids are phosphatidyl ethanolamine, phosphatidyl serine, and phosphatidyl choline. Minor phospholipids identified are phosphatidyl inositol, lysophosphatidyl choline, lysophosphatidyl ethanolamine, phosphatidyl glycerol, and cardiolipin. No significant differences were noted in fatty acid composition.
A method of preparing rabbit leukocytes for use in the capillary-migration test. Studies using particulate and soluble-sensitizing antigens
Authors: Malloy W. F. , Matheson B. H. , Reed R. W.
Published: February 2010

The use of peripheral blood leukocytes in the capillary-migration test is presently a very active area of investigation. A technique was developed in our laboratory which made possible the use of rabbit leukocytes in this in vitro test for cellular reactivity. Using a combination of gelatin sedimentation and sucrose-density gradient centrifugation, it was possible to harvest white cell populations from 59 rabbits which had median percentages of 74% mononuclear cells and 26% granulocytes with a median percent recovery of 34% of cells for the entire group. When testing cell populations from rabbits sensitized with killed mycobacteria, significant inhibition of migration was found when particulate antigen was included in the tissue-culture medium. Purified Protein Derivative (PPD) failed to elicit a similar response under the same conditions of experiment. Migration inhibition was also found when cells from animals immunized with ovalbumin were tested in the presence of specific antigen.
Cultivation and properties of Neisseria sp. grown in chemically defined media
Authors: Kenny C. P. , Diena B. B. , Wallace R. , Greenberg L.
Published: February 2010

Neisseria Chemically Defined Medium (NCDM) has been used routinely in our laboratory for a variety of purposes. The present report describes the development of NCDM agar, wherein the NCDM base is sterilized by filtration and defined supplements and agar are added. The medium is transparent and both meningococci and gonococci grow within 72 h. When grown on NCDM agar, Types 2 and 3 gonococcal colonies tend to revert to Type 1. The serological grouping of meningococci with specific antisera is not affected by growth on this medium.Parallel investigations on the growth of these species in liquid NCDM demonstrated that the yield of Neisseria gonorrhoeae is enhanced when the medium is sterilized by filtration.
Pectolytic and cellulolytic enzymes associated with Helminthosporium leaf spot on Kentucky bluegrass
Authors: Muse R. R. , Couch H. B. , Moore L. D. , Muse Barbara D.
Published: February 2010

Using maceration, viscometric, and spectrophotometric tests, culture filtrates and extracts of healthy and Helminthosporium sativum-infected common and Merion Kentucky bluegrass foliage were tested for pectolytic and cellulolytic enzymes. Culture filtrates, in which pectin was the carbon source, exhibited polymethylgalacturonase and pectin methyl-trans-eliminase activity, with optima of pH 6–7 and pH 8, respectively. Extracts from diseased foliage of common and Merion Kentucky bluegrasses contained pectin methylesterase, optimum activity at pH 7; trans-eliminase, most active at pH 8–9.5; and cellulase (Cx), most active at pH 6. These enzyme activities were always higher in diseased Merion than common Kentucky foliage. Enzyme preparations of diseased common bluegrass also produced polygalacturonase, optimum activity at pH 6, while diseased Merion extracts produced polymethylgalacturonase, with maximum activity at pH 6. Partial purification of the trans-eliminase enzymes indicated they were endopolygalacturonate-trans-eliminases. Extracts of healthy foliage of both varieties contained high pectin methylesterase and low cellulase (Cx) activity.
D-Arabitol production by Endomycopsis burtonii in sugarcane juice media
Authors: Falanghe H. , Caruso J. G. B.
Published: February 2010

Various sugarcane juice media were tested for the production of D-arabitol by Endomycopsis burtonii. The influence of magnesium, phosphorus, potassium, and nitrogen concentration in sugarcane juice media upon D-arabitol production was studied. Concentration of phosphorus previously suggested for good production of D-arabitol in synthetic medium by E. burtonii, decreased polyol production by this microorganism on sugarcane juice media, under the conditions of this work. Medium containing 50% of sugarcane juice with the addition of 0.09% urea was found to be the best sugarcane juice substrate for D-arabitol production. In this medium the microorganism produced the polyol at good yield of about 42% of sugar consumed, after 48 h of fermentation.
Ultrastructural studies of Sphaerophoms varius and the infective process of an associated bacteriophage
Authors: Bradley David E.
Published: February 2010

The anaerobe Sphaerophoms varius was found by electron microscopy to be a typical Gram-negative organism in its ultrastructural anatomy. However, the following additional characteristic features were observed; small (25–100 nm), membrane-bound dark bodies, groups of thin, rod-shaped inclusions, and pointed poles. An associated bacteriophage was found to consist of an octahedron with a very short tail like coliphage T3. It proved to be temperate and was released in large quantities by the mitomycin C induction of a lysogenized clone of the host organism. Induction also produced rods (identified with those in sections), and empty capsids believed to be of viral origin. Electron microscopy showed that the virulent infective process caused structural changes in the nucleoplasm before phage assembly and release; this was achieved by a single break in the cell envelope. It was concluded that S. varius was able to support at least two different plasmids, a bacteriophage and a probable bacteriocin.
Fungal degradation of 1-naphthol
Authors: Bollag J. -M. , Llu S. -Y.
Published: February 2010

The biological degradation of 1-naphthol was studied during growth, with replacement cultures and cell extracts of the fungus Fusarium solani. Radioactivity of 1-naphthol-1-14C disappeared partially during growth, but it was completely dissipated by cell-extract activity. More than 80% of 14CO2 evolved was collected after 60 min incubation in a cell-extract experiment. The active enzymes seem to be constitutive inasmuch as 1-naphthol was metabolized with cells which were not cultured on an inducing substrate. No difference in activity could be observed between cell-free extracts prepared from spores or mycelium of the fungus.
Ovine ill-thrift in Nova Scotia. 4. The survival at low oxygen partial pressure of fungi isolated from the contents of the ovine rumen
Authors: Brewer D. , Duncan J. M. , Safe S. , Taylor A.
Published: February 2010

Aspergillus fumigatus, Mucor rouxii, and Sporormia minima have been isolated from the rumen contents of sheep grazing permanent pasture at Nappan, Nova Scotia. To determine the ability of these fungi to survive and grow at the low oxygen partial pressure present in the rumen, a method of determination of oxygen, nitrogen, and carbon dioxide has been developed. The lowest partial pressures of oxygen [Formula: see text] and nitrogen that could be detected were 0.0005 cm Hg and the precision of the determination was ±0.001 cm Hg. Carbon dioxide was determined with slightly less precision than achieved for oxygen and nitrogen. Using this method, respiration was detected in cultures of all the fungi named at [Formula: see text] Hg and growth was observed at [Formula: see text] Hg in the case of M. rouxii. It is concluded that all these fungi are capable of survival in the ovine rumen.
Ovine ill-thrift in Nova Scotia. 5. The production and toxicology of chetomin, a metabolite of Chaetomium spp.
Authors: Brewer D. , Duncan J. M. , Jerram W. A. , Leach C. K. , Safe S. , Taylor A. , Vining L. C. , Archibald R. McG. , Stevenson R. G. , Mirocha C. J. , Christensen C. M.
Published: February 2010

Chetomin is a metabolite of Chaetomium cochliodes and C. globosum. It is produced by C. cochliodes on a denned medium and the yield is increased about 50-fold by the addition of corn steep liquor to the culture medium. Five single spore isolates of C. cochliodes (HLX 440) all produced chetomin and one of them produced appreciable quantities of a metabolite related to chetomin but having a S:N ratio of 1:1. Previous reports of the antibacterial activity of chetomin were confirmed and the antibiotic was shown, in addition, to inhibit the mycelial growth of some fungi. At 0.02 μg/ml, it inhibited protein synthesis in cultures of HeLa cells. Its oral LD50 in rats was 75 mg/kg, and in turkeys, 30 mg/kg. No pathological changes were observed in lambs dosed orally at 30 mg/kg but a single intraperitoneal dose of chetomin at 5 mg/kg resulted in the death of half the animals treated. Sublethal oral doses in all the animal species mentioned resulted in loss of body weight.
Mutants of Bacillus cereus strain T that produce thermoresistant spores lacking dipicolinate and have low levels of calcium
Authors: Hanson R. S. , Curry M. V. , Garner J. V. , Halvorson H. Orin
Published: February 2010

Mutants of Bacillus cereus strain T that produce thermoresistant spores which lack dipicolinic acid and have low levels of calcium and manganese have been isolated. The thermoresistant dipicolinate-less spores lose thermoresistance upon storage in distilled water and do not germinate in any liquid medium tested. All spores germinated and produced colonies on G medium agar. It is suggested that calcium and dipicolinic acid are not required for the acquisition of thermoresistance in bacterial endospores but that they are essential to the maintenance of the thermorésistant state and are required for normal germination.
An approach to quantitative antibiotic sensitivity testing for some Gram-negative pathogens
Authors: Chadwick P.
Published: February 2010

The twofold dilution method for quantitative antibiotic sensitivity testing in agar is applicable where each antibiotic concentration in the series is the minimal inhibiting one for a significant proportion of cultures to be tested. The method is of much less relevance where cultures show a biphasic distribution consisting of very sensitive and highly resistant components, or where the margin between the minimal inhibiting concentration (m.i.c.) and attainable blood concentration is small, so that response to a single critical concentration becomes of prime importance.Experiments indicated (a) that kanamycin sensitivity of most Enterobacteria could be measured adequately by their qualitative responses to a single drug concentration (8 μg/ml); (b) that sensitivity of Pseudomonas aeruginosa to gentamicin could be measured in terms of log reduction in viable population by a concentration of 4 μg/ml; and (c) that the classical twofold dilution method was suitable for measuring the sensitivity of P. aeruginosa to carbenicillin.The principle established is that the method of quantitative testing should be adapted to the antibiotic–bacterium system under study.
An extracellular proteolytic enzyme from Scopalariopsis brevicaulis. II. Hydrolysis of poly amino acids
Authors: Singh Kartar , Vézina Claude
Published: February 2010

Scopulariopsis brevicaulis protease hydrolyzed poly-L-lysine and poly-L-glutamic acid; optimum pH values for hydrolysis were 10.6 and 4.7 respectively. Final products of poly-L-lysine digestion by the protease were intermediate peptides from tetramer upwards. Pentalysine was not hydrolyzed by the enzyme. The protease had no action on poly-L-aspartic acid, poly-L-alanine, poly-L-glycine, poly-L-valine, or poly-L-leucine.
Cell-wall composition and viomycin resistance in Rhizobium meliloti
Authors: MacKenzie C. R. , Jordan D. C.
Published: February 2010

Mutation to viomycin-resistance in Rhizobium meliloti R21 resulted in an accumulation of phosphatidylcholine and phosphatidylethanolamine in the cell wall. Resistance to viomycin decreased when the excess lipid was removed by EDTA or when its synthesis was prevented by growth of normally resistant cells at 40 °C. Microelectrophoretic data showed binding of viomycin to the cell surface and it is proposed that the mechanism of resistance to viomycin is an immobilization of the antibiotic in the surface layers of the cell as a result of combination with phospholipid.