Honey-coloured,sessile Endogone spores

Summary Wall structure is described in the parent and resting spores of an Endogone sp. with honey-coloured, sessile spores. Wall thickness increases in the parent spore and subtending hypha by passage of material through the plasmalemma, or by formation of an apparently separate inner wall and degeneration of the trapped cytoplasm. Structure and development of the multi-layered wall of the mature resting spore are described. Unusual features are: 1. the incorporation of many pigment granules into the coloured outer wall, 2. the presence between the outer coloured and inner transparent walls of a tripartite membrane and adjacent layer with a regular periodicity and 3. a sectored layer with a crystalline component. The structure of the wall is discussed with reference to that of other mucoraceous fungi, to spore germination and to the mechanism of wall formation.     

Solid-phase capture of proteins, spores, and bacteria

Current methods for the detection of pathogens in food and water samples generally require a preenrichment step that allows selective enrichment of the test organism. The objective of this research was to eliminate an enrichment step to allow detection of bacteria directly in food and water samples in 30 min. A high-flow-rate, fluidized bed to capture and concentrate large (bacteria and spores) and small (protein) molecules was developed. This format, ImmunoFlow, is volume independent and uses large beads (greater than 3 mm in diameter) when capturing bacteria to prevent sample clogging when testing food samples. Detection of bound targets was done using existing enzyme-linked immunosorbent assay (ELISA) protocols. Four antibodies (anti-Escherichia coli O157:H7, -Bacillus globigii, -bovine serum albumin [BSA], and -ovalbumin [OVA]) were covalently coupled to various glass and ceramic beads. Very small amounts of BSA (<1 ng) and OVA (0.2 to 4.0 microg) were detected. Various industrial and environmental samples were used to observe the effect of the sample composition on the capture of anti-B. globigii and anti-E. coli O157:H7 modified beads. The lower limit of detection for both E. coli O157:H7 and B. globigii was 1 spore/cell independent of the sample size. The activity of anti-B. globigii modified beads declined after 3 days. Anti-E. coli O157:H7 modified beads declined in their capture ability after 2 days in various storage buffers. Storage temperature (4 and 25 degrees C) did not influence the stability. The ImmunoFlow technology is capable of capturing bacteria and spores directly from samples, with subsequent detection in an ELISA format in 30 min.     

Study of airborne fungal spores in Madrid, Spain

The concentration of fungal spores in the atmosphere of Madrid was recorded and analyzed for the year 2003. Airborne spores were sampled continuously with a Hirst-type spore trap located on the roof of a building of the School of Pharmacy, at about 8 m above ground level. Correlation between the mean daily spore concentrations and meteorological variables were explored by means of Spearman’s correlation analyses. Seventy spore types were identified, of which the most numerous were Cladosporium, Aspergillaceae (conidia), Coprinus, Agaricales (basidiospores), Ustilago (teliospores) and Pleospora (ascospores). These six types of spores represented more than 70% of the total. Cladosporium represented 41% of the total fungal spores, while Ustilago spores, the concentrations of which in May and June exceeded 47% of the monthly total spore count, constituted the second most important group. Spores reached their highest concentrations in the spring months, and in the autumn, mainly in October. A␣positive significant correlation was found between airborne spore counts and temperature and relative humidity. The results provide a picture of the spectrum of airborne fungal spores present in the atmosphere of Madrid and of the `peak' periods of their presence. Future studies will provide more detailed information on the seasonal dynamics of the spores most frequently found in the air as well as on the extent to which atmospheric conditions influence their release, dispersion and sedimentation processes.     

Late Silurian trilete spores from northern Jiangsu, China

The Late Silurian is generally considered to a particular significant key period in the study of early land vascular plants. A trilete spore assemblage of the Upper Silurian is described from northern Jiangsu, China. This assemblage comprises 11 genera and 20 species of trilete spores (including laevigate, apiculate, perinotrilite, patinate, rarely distally murornate and equatorially crassitate, and three indeterminate trilete miospores forms). It has similarities to those described from coeval assemblages from around the world (e.g., England and South Wales; Tripolitania, Libya; Cornwallis Island, Canadian Arctic; Northwest Spain). The rare cryptospore, only one specimen (Tetrahedraletes sp.) had been found to be associated with the Chinese trilete spore assemblage. The discovery of the trilete spores from Late Silurian rocks indicates the existence of early land plants, some possibly vascular, at that time in northern Jiangsu, China.     

Lyophilization, vacuum drying, and subsequent storage of Nosema pyrausta spores

Methods of preserving Nosema pyrausta spores were developed by subjecting laboratoryreared, nondiapausing larvae of the European corn borer, Ostrinia nubilalis, infected with N. pyrausta to different techniques of lyophilization and vacuum drying. Such material was still viable when it was stored in an airtight container and held at ?12°C for 12 months, or when it was stored in a vacuum desiceator and held at 22–24°C for 6 months.     

Airborne pollen, spores, and dust across the East Mediterranean Sea

Airborne pollen and spores, as well as airflow directions, were continuously monitored during a cruise across the East Mediterranean from Tel Aviv, Israel, to Istanbul, Turkey. In spite of the fact that a high-altitude dust cloud moved, at that, time from North Africa, across the East Mediterranean, only a few dust particles were monitored on the boat. The numbers of counted airborne pollen along the cruise path were rather small. This is, in part, because the trip was taken after the main flowering season in the East Mediterranean region. Nevertheless, airborne pollen grains were still found, either as a result of remnant pollen releases by late-flowering plants or because of secondary lift-up of previously settled pollen. The presented pollen counts are average pollen counts /m³ air /6 h. The counts ranged between ∼5 pollen/m³ of air in mid-sea (July 16th–July 17th) or ∼6 pollen/m³ of air on the Israeli coast (July 16–July 17th), and 30 pollen/m³ of air near the coasts of Turkey and of the Greek Islands (July 18th–July 19th) and some 18 taxa of pollen were identified, most of them at the family level. Some 30 taxa of different spores were recorded. The numbers of airborne spores were relatively low in mid-sea (300–750 spores/m³ air), but were high near the coasts of Turkey (1,200–2,400 spores/m³ air) and of Israel (340–1,695 spores/m³ air).     

Chaetoceros resting spores in the Gerlache Strait, Antarctic Peninsula

The formation of resting spores in diatoms is a common phenomenon in neritic environments. Here we report on resting spores of the genus Chaetoceros associated with a layer of increased chlorophyll fluorescence, at a depth of more than 200 m, north of Brabant Island and in Wilhelmina Bay, southeast coast of the Gerlache Strait (64°41.0′S, 62°0.5′W). Six species of Chaetoceros were identified by the morphology and size of the resting spores. Given that Chaetoceros spp., both in vegetative cells and as resting spores, are commonly found in Antarctic coastal surface waters, their location at depth could represent the pelagic “waiting” or “seeding” populations mentioned for other environments. Received: 25 November 1996 / Accepted: 16 November 1997     

The aerobiological significance of smut spores in Tulsa,Oklahoma

Few aerobiological studies have focused on smut spores, teliospores of fungi within the order Ustilaginales, but the scientific literature provides evidence of the potential aerobiological significance of these plant pathogens. The atmosphere in Tulsa, Oklahoma was monitored for the presence of smut teliospores using a Burkard Volumetric Spore Trap. Smut spores were identified in the atmospheric samples every day from May to October during 1991 and 1992 at concentrations that were normally below 1000 spores/m³. The peak concentration observed during this study was almost 6000 spores/m³. Daily concentrations fluctuate due to a variety of factors such as precipitation, relative humidity, percent sunshine, and the phenology of fungi in relation to their hosts. In northeastern Oklahoma, the most prevalent species of smuts in the atmosphere during the spring includeSphacelotheca occidentalis, Ustilago tritici, andU. kolleri. In the fall, spores ofU. brumivora, U. bullata, andU. maydis are more common.     

Survey of airborne fungus spores at Taif,Saudi Arabia

Fifty-eight species and one variety belonging to 25 genera were collected from the atmosphere of Taif from August 1981 to July 1982 (12 exposures for each type of media) on glucose- and cellulose-Czapek's agar plates at 28 °C.The total counts of sugar and cellulose-decomposing airborne fungi showed seasonal fluctuations; the maxima were recorded in winter, and the minima in summer months. Aspergillus (16.23% and 13.22% of total fungi on glucose and cellulose media, respectively), Alternaria (11.52% and 15.7%), Cladosporium (18.59% and 9.5%), Drechslera (4.7% and 10.74%), Scopulariopsis (7.33% and 6.6%) and phoma (8.12% and 11.98%) were recovered in high seasonal occurrence on the two media. Also, Penicillium (on glucose) and Ulocladium (on cellulose) were common in the air accounting for 10.73% and 7.44% of total fungi, respectively.     

Photodynamic inactivation of Bacillus spores, mediated by phenothiazinium dyes

Spore formation is a sophisticated mechanism by which some bacteria survive conditions of stress and starvation by producing a multilayered protective capsule enclosing their condensed DNA. Spores are highly resistant to damage by heat, radiation, and commonly employed antibacterial agents. Previously, spores have also been shown to be resistant to photodynamic inactivation using dyes and light that easily destroy the corresponding vegetative bacteria. We have discovered that Bacillus spores are susceptible to photoinactivation by phenothiazinium dyes and low doses of red light. Dimethylmethylene blue, methylene blue, new methylene blue, and toluidine blue O are all effective, while alternative photosensitizers such as Rose Bengal, polylysine chlorin(e6) conjugate, a tricationic porphyrin, and a benzoporphyrin derivative, which easily kill vegetative cells, are ineffective. Spores of Bacillus cereus and B. thuringiensis are most susceptible, B. subtilis and B. atrophaeus are also killed, and B. megaterium is resistant. Photoinactivation is most effective when excess dye is washed from the spores, showing that the dye binds to the spores and that excess dye in solution can quench light delivery. The relatively mild conditions needed for spore killing could have applications for treating wounds contaminated by anthrax spores, for which conventional sporicides would have unacceptable tissue toxicity.     

The aerobiological significance of smut spores in Tulsa,Oklahoma

Few aerobiological studies have focused on smut spores, teliospores of fungi within the order Ustilaginales, but the scientific luterature provides evidence of the potential aerobiological significance of these plant pathogens. The atmosphere in Tulsa, Oklahoma was monitored for the presence of smut teliospores using a Burkard Volumetric Spore Trap. Smut spores were identified in the atmospheric samples every day from May to October during 1991 and 1992 at concentrations that were normally below 1000 spores/m³. The peak concentration observed during this study was almost 6000 spores/m³. Daily concentrations fluctuate due to a variety of factors such as precipitation, relative humidity, percent sunshine, and the phenology of fungi in relation to their hosts. In northeastern Oklahoma, the most prevalent species of smuts in the atmosphere during the spring includeSphacelotheca occidentalis, Ustilago tritici, andU. kolleri. In the fall, spores ofU. brumivora, U. bullata, andU. maydis are more common.     

Uninucleate spores of Phycomyces

Summary Under most culture conditions only 0.3% of the vegetative spores of Phycomyces blakesleeanus are uninucleate. On an acidified minimal medium, the uninucleate fraction can be raised up to 4.5% of the spores. The spore population can be fractionated in a gradient under gravity (1xg) yielding fractions that contain over 80% uninucleate spores. These uninucleate spores are fully viable. When the spores to be fractionated are obtained from a heterokaryotic mycelium, the uninucleate fraction produces homokaryotic mycelia.     

Lyophilized Streptomyces aureofaciens spores

The viability of mutant strains of Streptomyces aureofaciens (106 spores/0.2ml) and tetracycline production remained stable for stored lyophilized spores. The same mutant produced (9375±1584) and (12336±1023) g/g of tetracycline (p<0.01), respectively for spores lyophilized in the media: (i) control skim milk with added sucrose and sodium glutamate, and (ii) synthetic polyvinylpyrrolidone plus sucrose, peptone and sodium glutamate.     

Hydrophobic characteristics ofBacillus spores

Spores from severalBacillus species displayed a strong affinity for hexadecane and other hydrophobic solvents. The binding ofBacillus subtilis spore suspensions to octyl-Sepharose was enhanced by ammonium sulfate and other salts, but was inhibited by detergents. Treatment of spore suspensions with strong denaturants promoted their adherence to hexadecane, presumably by exposing hydrophobic residues in coat proteins. The hydrophobic characteristics of spores may be important in the ecological adaptation of certain bacteria.