DECOMPOSITION AND BINDING ACTION OF A POLYSACCHARIDE FROM CHROMOBACTERIUM VIOLACIUM IN SOIL

Martin, J. P. (University of California, Riverside) and S. J. Richards. Decomposition and binding action of a polysaccharide from Chromobacterium violaceum in soil. J. Bacteriol. 85:1288-1294. 1963.-The decomposition rate and binding effect in soil of a polysaccharide from Chromobacterium violaceum was compared with that of a variety of bacterial and plant polysaccharides and more complex organic residues. Most of the polysaccharides tested decomposed more readily than mature plant residues and fungus mycelium. The ease of decomposition varied, however, and polysaccharide from C. violaceum over a period of 1 month was more resistant than corn stalks, Rhodes grass, bean straw, and orange leaves. During the first week, it was as resistant to decay as pine needles. The C. violaceum polysaccharide was more effective in binding or aggregating the soil than all others tested. It also reduced the bulk density of Greenfield sandy loam and increased hydraulic conductivity in neutral soil.

INFECTION OF WHITE SWISS MICE WITH AIRBORNE CRYPTOCOCCUS NEOFORMANS

Smith, C. D. (Communicable Disease Center, Kansas City, Kansas), R. Ritter, H. W. Larsh, and M. L. Furcolow. Infection of white Swiss mice with airborne Cryptococcus neoformans. J. Bacteriol. 87:1364-1368. 1964.-A group of 39 white Swiss male mice were allowed to run 3 days on previously sterilized soil that had been seeded with Cryptococcus neoformans 1 year previously. It was determined that the soil contained an average of 1.6 x 10(6) viable yeast cells per ml. The mice were observed for 24 weeks, at which time the survivors were necropsied. The total mortality rate during this period was 44%; 67% of the mice had positive cultures, including all who had a fatal infection. Two additional experiments were done with the same strain with the use of aerosols produced by a Henderson apparatus. In experiment 1, 39 mice received 11,000 viable cells each; in experiment 2, 40 mice received 14,622 viable cells. Both groups of mice showed similar mortality rates, with a total of 77% dead after 20 weeks in experiment 1, and 80% in experiment 2. All of the mice in experiment 1 had positive cultures, as did 95% of the mice in experiment 2.

VIGOROUS MOLD GROWTH IN SOILS AFTER ADDITION OF WATER-INSOLUBLE FATTY SUBSTANCES

Various water-insoluble fatty compounds, when added to soil in finely divided form, will support as high-caloric nutrients a visible, vigorous growth of the molds, Fusarium solani Mart., F. diversisporum Sherb., and F. equiseti. n-Paraffins and olefins are most effective, because the effect of additives is reduced to the extent that oxygen atoms are introduced into the molecule. n-Fatty alcohols support growth in soil almost as well as the paraffins; however, growth is reduced when branched-chain compounds are added as nutrients. Compounds that will support mold growth when added to air-dried soil as finely powdered solids will not do so when incorporated at temperatures above their melting point, but will produce dense growth when applied to wet soil in this form. Mold growth is correlated with degradation of fatty matter. The rate of degradation is controlled by the availability of water, oxygen, and the basic inorganic nutrients.

ENZYMATIC HYDROLYSIS OF YEAST CELL WALLS. I. ISOLATION OF WALL-DECOMPOSING ORGANISMS AND SEPARATION AND PURIFICATION OF LYTIC ENZYMES

Tanaka, Hirosato (University of California, Davis), and Herman J. Phaff. Enzymatic hydrolysis of yeast cell walls. I. Isolation of wall-decomposing organisms and separation and purification of lytic enzymes. J. Bacteriol. 89:1570-1580. 1965.-A number of microorganisms, able to decompose and grow on yeast cell walls, were isolated from soil. These isolates demonstrated various types of attack on yeast walls. A bacterium, identified as Bacillus circulans, and a species of Streptomyces produced clear, lysed zones when grown on an agar medium containing baker's yeast cell walls. The streptomycete formed glucanase, mannanase, and protease, but B. circulans produced only glucanases. Purified mannan could be prepared from the culture fluid of B. circulans grown on baker's yeast cell walls. In a liquid, mineral medium, extracellular lytic enzyme production by B. circulans was optimal after 3 days of aerobic growth at 30 C with 0.5% baker's yeast cell walls as the carbon source. Twelve other carbon sources were ineffective as inducers. Among a number of polysaccharides tested, the crude enzymes of B. circulans hydrolyzed only beta-1-->3 glucan (laminarin) and beta-1-->6 glucan (pustulan), both by a random mechanism, to a mixture of dimer and glucose. The beta-1-->3 and beta-1-->6 glucanases were separated from each other by diethylaminoethyl cellulose column chromatography. Water-soluble oat glucan, which contains in the linear chain both beta-1-->3 and beta-1-->4 bonds, was also hydrolyzed by the bacterial beta-1-->3 glucanase. The products of this reaction indicated that this enzyme hydrolyzes beta-1-->3 or beta-1-->4 glucosidic linkages, provided the beta-glucopyranosyl units composing these bonds are substituted in the 3 position by another glucose unit.

SIGNIFICANCE OF SOIL SALINITY ON THE ECOLOGY OF COCCIDIOIDES IMMITIS

Elconin, Ann F. (University of Southern California, Los Angeles), Roger O. Egeberg, and Margaret C. Egeberg. Significance of soil salinity on the ecology of Coccidioides immitis. J. Bacteriol. 87:500-503. 1964.-An 8-year study of the soil in a small parcel of land where coccidioidomycosis is endemic was conducted. Over 5,000 samples collected from the surface of the soil at monthly intervals were tested for the presence of Coccidioides immitis. These samples were also analyzed to determine their major chemical composition. During the first 3 years, C. immitis was recovered in profusion from the spring samples, but during the next 4 years the fungus virtually disappeared from this endemic area. C. immitis reappeared in the spring of the final year of this study. There had been no significant deviation in the climatic conditions, flora, or fauna of the region. Chemical analysis of soils showed a marked elevation of the soluble salts (principally Na, Ca, SO(4), and Cl) during those years when C. immitis was recovered. The soluble salts, expressed in terms of the saturation extract conductivity, ranged from 11 to 27 in those spring seasons when C. immitis was recovered, and from 3.5 to 8.8 when it was not found. This degree of correlation indicates that the high level of surface salinity encouraged the growth of C. immitis, and could be a factor in accounting for the spotty distribution of this fungus within endemic areas.

SURVIVAL OF MICROORGANISMS IN A SIMULATED MARTIAN ENVIRONMENT. I. BACILLUS SUBTILIS VAR. GLOBIGII

Survival of Bacillus subtilis var. globigii in a simulated Martian environment was demonstrated. Previous contact with the simulated Martian soil or atmosphere reduced germination or outgrowth of unheated spores, or both. Inoculation into simulated Martian soil and then flushing with a simulated Martian atmosphere were lethal to both vegetative cells and spores. After one diurnal temperature cycle (26 to -60 C), the majority of of cells present were spores. No further effect of the diurnal cycle on survival was noted in any of the experimental samples.

OBLIGATELY PSYCHROPHILIC YEASTS FROM THE POLAR REGIONS

Sixty-seven pure cultures of psychrophilic bacteria and yeasts were isolated from polar ice, snow, soil, and other materials. Low temperatures were maintained during all phases of the isolation procedure to avoid possible destruction of obligate psychrophiles. Four of the cultures, all yeasts, proved to be obligate psychrophiles. Three are species of Candida and one of Torulopsis. They grew in the range of 0 °C to 20 °C and the optimum growth temperature was 15 °C. They died rapidly when exposed to temperatures of 30 °C or 40 °C.The rate of fermentation of glucose by psychrophilic Candida sp. P16 was higher than that of mesophilic Saccharomyces cerevisiae at temperatures below 25 °C. At and above 25 °C, this rate relationship was reversed and at 35 °C all fermentative activity of the psychrophilic yeast was destroyed while that of the mesophile was maximal. Oxidative activity of Candida sp. P16 was much less sensitive to 35 °C, which suggests that fermentation and oxidation proceed by different pathways.The extent of occurrence of obligately psychrophilic microorganisms in nature is discussed.

MORPHOLOGY AND PHYSIOLOGY OF METHANOMONAS METHANOOXIDANS

Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Morphology and physiology of Methanomonas methanooxidans. J. Bacteriol. 88:1071-1077. 1964.-Pure cultures of methane-oxidizing bacteria isolated from soil, from the rumen of a fistulated cow, and from coalmine water were found to be identical in morphological, cultural, and physiological characteristics with Methanomonas methanooxidans of Brown and Strawinski. Two of the isolates were serologically related to the organism of Brown and Strawinski. All the strains required methane for good growth, but a delayed moderate growth occurred on methanol. No other substances were utilized as carbon and energy source. Nitrogen requirements were satisfied by nitrates, ammonium salts, peptone, or certain amino acids. The taxonomic position of the species is discussed.

ABUNDANT MICROORGANISM IN SOIL

The presence in soil of large numbers of a catalase-negative, microaerophilic, coccoid microorganism was demonstrated. Use of media of high nutrient value, without incorporation of inhibitors, and growth in the absence of antagonistic microorganisms were utilized to isolate this organism from soil dilutions greater than those providing growth by other means. The organism described does not grow on soil extract agars and is missed by conventional counting techniques for soil organisms. On the basis of morphological and growth characteristics, this organism appears to have at least some taxonomic relationships to the families Actinomycetaceae and Mycobacteriaceae. It is proposed that this organism makes up much of the coccoid microflora of soil as observed by light and ultraviolet fluorescence microscopy.

CLOSTRIDIUM RUBRUM SP. N. AND OTHER PECTINOLYTIC CLOSTRIDIA FROM SOIL

Ng, Henry (University of California, Davis) and Reese H. Vaughn. Clostridium rubrum sp. n. and other pectinolytic clostridia from soil. J. Bacteriol. 85:1104-1113. 1963.-Reports in the literature and results of experiments described herein suggest that pectinolytic anaerobes constitute a very heterogeneous group. The cultures isolated in this study all belonged to the genus Clostridium. The following species were identified: C. butyricum, C. fallax, C. multifermentans, and C. indolis. In addition, a species believed to be previously undescribed was named C. rubrum sp. n. The ability to ferment galacturonic acid was found to be adaptive. Some cultures fermented pectin and pectic acid to the same degree, whereas others fermented pectin only partially. The partial fermentation was attributed to the lack of a pectinesterase. On the basis of fermentation balances, it was concluded that the four strains of galacturonic acid fermenters selected for study yielded identical end products in approximately the same proportions. Per mole of galacturonic acid fermented, about 2 moles of CO(2), 1.5 moles of H(2), 1.5 moles of acetic acid, and 0.25 mole of butyric acid were produced.

OXIDATIVE METABOLISM OF PHENANTHRENE AND ANTHRACENE BY SOIL PSEUDOMONADS. THE RING-FISSION MECHANISM

1. Phenanthrene is oxidatively metabolized by soil pseudomonads through trans-3,4-dihydro-3,4-dihydroxyphenanthrene to 3,4-dihydroxyphenanthrene, which then undergoes cleavage. 2. Some properties of the ring-fission product, cis-4-(1-hydroxynaphth-2-yl)-2-oxobut-3-enoic acid, are described. The Fe(2+)-dependent oxygenase therefore disrupts the bond between C-4 and the angular C of the phenanthrene nucleus. 3. An enzyme of the aldolase type converts the fission product into 1-hydroxy-2-naphthaldehyde (2-formyl-1-hydroxynaphthalene). An NAD-specific dehydrogenase is also present in the cell-free extract, which oxidizes the aldehyde to 1-hydroxy-2-naphthoic acid. This is then oxidatively decarboxylated to 1,2-dihydroxynaphthalene, thus allowing continuation of metabolism via the naphthalene pathway. 4. Anthracene is similarly metabolized, through 1,2-dihydro-1,2-dihydroxyanthracene to 1,2-dihydroxyanthracene, in which ring-fission occurs to give cis-4-(2-hydroxynaphth-3-yl)-2-oxobut-3-enoic acid. The position of cleavage is again at the bond between the angular C and C-1 of the anthracene nucleus. 5. Enzymes that convert the fission product through 2-hydroxy-3-naphthaldehyde into 2-hydroxy-3-naphthoic acid were demonstrated. The further metabolism of this acid is discussed. 6. The Fe(2+)-dependent oxygenase responsible for cleavage of all the o-dihydroxyphenol derivatives appears to be catechol 2,3-oxygenase, and is a constitutive enzyme in the Pseudomonas strains used.

RADIATION RESISTANCE OF SOIL AZOTOBACTER

Vela, Gerard R. (School of Aerospace Medicine, Brooks Air Force Base, Tex.), and Orville Wyss. Radiation resistance of soil Azotobacter. J. Bacteriol. 89:1280-1285. 1965.-Quantitative recovery of Azotobacter from soils subjected to gamma-radiation from a cobalt-60 source showed the soil populations to be much more highly resistant than isolates from such cultures grown on laboratory media. Even in the encysted state, the laboratory populations were reduced 10,000-fold by exposure to 200 kr, whereas the soil populations were not measurably reduced by that dose.

HISTOPLASMA CAPSULATUM: OCCURRENCE IN SOIL FROM THE EMILIA-ROMAGNA REGION OF ITALY

The existence of an area in Europe in which histoplasmosis is endemic was revealed by the isolation of Histoplasma capsulatum from soil. The soil specimen was collected in a chicken yard on a farm near Bologna, Italy. The Emilia-Romagna region had been selected for study because several, apparently autochthonous, human cases of histoplasmosis had originated there.

HYDROLYSIS OF FIBROUS COTTON AND REPRECIPITATED CELLULOSE BY CELLULOLYTIC ENZYMES FROM SOIL MICRO-ORGANISMS

1. The action of cell-free filtrates from Trichoderma koningii was examined on undegraded cellulose in the form of cotton fibres, on degraded cellulose in the form of cellulose powder reprecipitated from phosphoric acid and on the soluble cellulose derivative CM-cellulose. 2. The cell-free filtrates compare favourably with intact cellulolytic micro-organisms in producing complete solubilization of undegraded as well as of degraded types of cellulose. Enzymic solubilization of cotton fibres gives quantitative conversion into glucose. Cellobiase is present. 3. The early enzymic breakdown of cotton fibres is characterized by the formation of very short fibres that increase to a maximum and disappear gradually by conversion into glucose. Disintegration of cotton fibres to short fibres is assisted by shaking, and within 20hr. the enzyme converts a minor fraction (up to 16%) of substrate into soluble products and a major portion (80%) into insoluble short fibres. 4. Maximum enzymic activity on cotton fibres occurs at about pH5.0, measured by the formation of short fibres, and at about pH3.8 on reprecipitated cellulose, measured by solubilization of the substrate. 5. Gluconolactone, glucose and cellobiose fail to produce marked inhibition of the enzymic hydrolysis of cotton fibres to short fibres or of the solubilization of reprecipitated cellulose unless present in amounts comparable with or greater than the initial weight of these two forms of cellulose. 6. The heavy-metal ions Cu(2+), Hg(2+) and Fe(3+) at 2mm concentration give 80-100% decrease in the enzymic breakdown of cotton fibres, measured by the formation of short fibres. At the same concentration Hg(2+) and Fe(3+) but not Cu(2+) also produce 70-100% inhibition of the solubilization of reprecipitated cellulose. 7. The ability to hydrolyse cotton fibres to short fibres and CM-cellulose to sugars is completely lost after heating enzyme preparations for 10min. at 71 degrees .

MICROBIAL DEGRADATION OF ISOPROPYL-N-3 -CHLOROPHENYLCARBAMATE AND 2-CHLOROETHYL-N-3-CHLOROPHENYLCARBAMATE

Microbial degradation of isopropyl-N-3-chlorophenylcarbamate (CIPC) and 2-chloroethyl-N-3-chlorophenylcarbamate (CEPC) was observed in a soil perfusion system. Degradation in perfused soils, and by pure cultures of effective bacterial isolates, was demonstrated by the production of 3-chloroaniline and the subsequent liberation of free chloride ion. Identified isolates effective in degrading and utilizing CIPC as a sole source of carbon included Pseudomonas striata Chester, a Flavobacterium sp., an Agrobacterium sp., and an Achromobacter sp. Identified isolates, effective in degrading and utilizing CEPC as a sole source of carbon, included an Achromobacter sp. and an Arthrobacter sp. CIPC-effective isolates degraded CEPC more slowly than CIPC, whereas CEPC-effective isolates degraded CIPC more rapidly than CEPC. Both CIPC- and CEPC-effective isolates degraded isopropyl N-phenylcarbamate (IPC) more rapidly than either CIPC or CEPC.

MICROBIAL DEGRADATION OF CORRINOIDS. I. VITAMIN B12

Scott, W. M. (Wayne State University, Detroit, Mich.), R. C. Burgus, J. B. Hufham, and J. J. Pfiffner. Microbial degradation of corrinoids. I. Vitamin B(12). J. Bacteriol. 88:581-585. 1964.-Microorganisms isolated from a variety of soil, sewage, and mud samples, and stock cultures, were examined for the ability to degrade vitamin B(12). More than 200 isolates which attack the vitamin were examined, and they all demonstrated reversible fading of the red vitamin. The color was restored by aeration. Very few microorganisms were able to degrade the vitamin to permanently colorless products, although many were able to degrade it partially, to produce new pigments. Some of these pigments appeared similar, if not identical, although they were produced by different bacteria. Radiotracer and electrophoretic mobility data are presented to show that the transformation products are derived from the vitamin. All the degradative microorganisms isolated were bacteria, and the most active was Pseudomonas rubescens.

ISOLATION OF CLOSTRIDIUM TETANI FROM SOIL

Sanada, Ichiro (Kanazawa University, Kanazawa, Japan), and Shoki Nishida. Isolation of Clostridium tetani from soil. J. Bacteriol. 89:626-629. 1965.-The higher the temperatures applied to soil specimens, the weaker the toxigenicity of Clostridium tetani strains isolated from them. The glucose- and maltose-fermenting ability of these isolates was inversely proportional to their toxigenicity. The biological properties of atoxic strains were indistinguishable from those of C. tetanomorphum. Since a considerable number of toxic strains fermented glucose and maltose, these criteria are of doubtful value for differentiating C. tetani from C. tetanomorphum.

BACTERIA RESPONSIBLE FOR MUCILAGE-LAYER DECOMPOSITION IN KONA COFFEE CHERRIES

The predominant microbial flora present during decomposition of the mucilage layer of Kona coffee cherries were gram-negative bacteria which fermented lactose rapidly. Cultures isolated from coffee cherries under-going fermentation included species of Erwinia, Paracolobactrum, and Escherichia. Unblemished cherry surfaces and coffee plantation soil also had a microflora containing a high proportion of bacteria belonging to these three genera. Of 168 isolates tested, the 44 strains capable of demucilaging depulped coffee cherries were all members of Erwinia dissolvens. Supernatant growth medium liquids, after removal of E. dissolvens cells, actively decomposed the mucilage layer of depulped cherries.