Airborne dust,bacteria, actinomycetes and fungi at a flourmill

A study was carried out on suspended dust, bacterial and fungal aerosols in a four-storey flourmill building located in Giza, Egypt. Airborne microorganisms were quantitatively isolated using liquid impinger and gravimetric samplers during the period from March 2004 to February 2005. Suspended dust varied from 1.96 to 16.3 mg m⁻³ and 0.69 to 1.8 mg m⁻³ in the indoor and outdoor environments, respectively. Suspended dust was significantly greater (P < 0.05) at bran package, double roller, purifiers and flour storage units in comparison to the outdoor reference site. The dust levels exceed the occupational exposure limit (OEL) of 0.5 mg m⁻³ for flour dust. Airborne microbial counts were found at median values, between sampling locations, ranged from 0 to >10⁴ CFU m⁻³. Gram-negative bacteria were found in small numbers (0–10² CFU m⁻³). The highest concentration of actinomycetes (>10³ CFU m⁻³) was detected in the storage unit. Airborne fungal counts were found at the median values, between sampling locations, varied from 10³ to 10⁴ CFU m⁻³. The counts of airborne bacteria and fungi were significantly greater (P < 0.05) at the purifiers and double roller mill units in comparison to the outdoor reference site using the liquid impinger sampler. Microbial levels associated with bulk deposited dust averaged between 10⁵ and 10⁶ CFU g⁻¹. Alcaligenes (5.4%) Pseudomonas (3.87%) and Enterobacter (3.1%) were the predominant Gram-negative species while Bacillus (29.4%) and Micrococci (13.9%) were the major components of Gram-positive bacteria. Aspergillus and Penicillium were the predominant fungal types indoor whereas Cladosporium (35.2%) and Aspergillus species (22.2%) were the predominant fungal types outdoor. A number of allergenic and toxigenic bioaerosols were found in the flourmill workplace.     

The biodiversity of air spora in an Italian vineyard

Biodiversity indices are frequently used to provide a numerical value of the diversity of species within an ecological community. To study fungal biodiversity in the air, a 7-day recording Hirst-type spore trap was used. The daily concentration of 124 taxa was recorded in an Italian vineyard. The predominant fungi were: Cladosporium spp., unknown 3-septate fusiform spore, and Alternaria spp. Shannon’s and Simpson’s biodiversity indices and evenness were calculated first for air spora. Meteorological circumstances affected the biodiversity; positive correlations were found between Simpson’s biodiversity index and precipitation, but no significant correlations were found with Shannon’s diversity index and evenness. To predict Simpson’s index for airborne fungi, regression analysis was performed. It was shown that the best estimator, sun hours, negatively affected the index. The biodiversity of the dominant species was low on dry days, since Cladosporium alone had much higher abundance on such days than other species.     

Physical and chemical characteristics of the Blue Nile and the White Nile at Khartoum

Fortnightly measurements of physical and chemical variables were made at two locations on the Blue and White Niles near Khartoum from August 1968 to December 1970. Variables analysed from each river were: temperature, pH, total residue, current velocity, oxygen, alkalinity, phosphate, nitrate, ammonia, silica, sulphate, iron, calcium, magnesium, sodium, potassium and oxidizable organic matter. The seasonal variations of these factors in the two Niles are compared and the interrelationships existing between some of them are discussed. Comparisons with earlier studies on the Nile and with some tropical rivers are made.In the Blue Nile, the amounts of suspended matter and nutrients are largely dependent upon the flood regime. Nitrate, phosphate, iron, oxidizable organic matter and total residue increase considerably in the Blue Nile when the river is in flood (peaks: 1 880 µg NO₃-N l^–1; 0.31 mg Fe l^–1; 3 842 mg total residue · l^–1).In the White Nile, concentrations of nitrate, phosphate, iron, oxidizable organic matter and total residue attain their peaks during the rainy season (270 µg NO₃-N l^–1; 163 tag PO₄-P l^–1; 0.46 mg Fe · l^–1; 502 mg total residue · l^–1).In both rivers, alkalinity, calcium, sodium and potassium tend to increase during the dry season while declining in the rainy season. Silica is depleted at certain times of the year, yet relatively high concentrations are maintained throughout the year and were not expected to limit growth of diatoms. Fall in silica concentrations, unlike nitrate, phosphate and iron, was always followed by a rapid restoration of a high level. Silica and magnesium showed no response to changes in discharge rates.     

A Feasibility Study to Monitor the Macroinvertebrate Diversity of the River Nile Using Three Sampling Methods

The River Nile is one of the world’s major rivers. Its’ catchment in Egypt has a population of 75,000,000. River flow is highly regulated and there are known discharges of pollutants. 1035 km of the river downstream of the Aswan high dam was studied to test the hypothesis that representative qualitative samples can be used to estimate macroinvertebrate biodiversity. Benthic macroinvertebrates are difficult to sample in large rivers and a reliable sampling strategy is required to evaluate their ecological status. Three methods for sampling have been investigated. Ekman Grab, macrophyte sweep netting and Artificial Substrate Samplers (ASS) were used to sample 15 sites from Aswan to Cairo between September 2001 and June 2002. Organisms were identified to species level where possible. Taxon accretion curves indicated that the all taxa present at a site should be collected using either 15 grab samples, 10 macrophyte samples or 5 ASS. The best time to sample was May–June. The biodiversity of macroinvertebrates in the Nile was recorded as 50 taxa with values of 7–31 at individual bank-side sites. Mid-stream biodiversity was much lower (0–19). Lowest biodiversity occurred at sites with known pollution inputs whilst highest occurred at sites with high levels of sedimentation. A regular programme for biomonitoring is recommended which will allow current status to be confirmed and future changes detected.     

黄山风景区空气真菌组成及其生态分布

用自然沉降法采集空气真菌,对黄山风景区14 个景点的空气真菌资源及其生态分布情况进行调查.共鉴定出空气真菌35 属,分隶于3 纲6 目10 科,其中以丛梗孢科占绝对优势, 有14 个属,占总属数的40.0 %;其次为暗梗孢科,有7 个属,占总属数的20.0 %.属的生态分布是:在7 个以上景点的空气中能够分离到的属有9 个, 其中芽枝霉属(Cladosporium)和无孢菌群(Mycelia Sterilia)在不同海拔的所有景点空气中普遍存在;海拔800 m 左右的空气中分离到的属较多,海拔高于1000m 的采样点分离到的属较少, 原因可能是随海拔降低, 气候变得温暖, 加上降雨量充沛,原生和次生常绿阔叶林发育良好, 大量枯落物归还土壤, 成为多种真菌丰富的营养来源, 故空气中分离到真菌的属较丰富, 数量也较多.     

Prevalence of culturable and non-culturable airborne fungi in a grain store in Delhi

Fungal spores are important aeroallergens and proper knowledge of their qualitative and quantitative prevalence in indoor and outdoor environments is of paramount importance in the study of allergic disorders. The present investigation was aimed at the study of seasonal and annual prevalence of fungi inside a large grain storage facility. Sampling was carried out from September 1989 to August 1991. Although fungal spores occurred throughout the year there was seasonal variation.Aspergillus flavus. Cladosporium spp.Epicoccum nigrum and basidiospores had a definite seasonal pattern.Aspergillus flavus andUstilago (smuts) were the most predominant fungi in the facility. Their concentration was significantly higher (P<0.05) than in outside air. The need to reduce fungal concentration in grain storage is emphasised.     

Occurrence of pppApp-synthesizing activity in actinomycetes and isolation of purine nucleotide pyrophosphotransferase

The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp adenosine 5-triphosphate 3-diphosphate - ppApp adenosine 5-diphosphate 3-diphosphate - pApp adenosine 5-monophosphate 3-diphosphate - pppGpp guanosine 5-triphosphate 3-diphosphate     

Production of B-group vitamins by mycorrhizal fungi and actinomycetes isolated from the root zone of pine (Pinus sylvestris L.)

Summary Studies were carried out on synthesis of B-group vitamins by mycorrhizal fungi and actinomycetes (Streptomyces sp.) derived from soil, rhizosphere and mycorrhizosphere of pine.None of the fungal isolates produced biotin. The vitamin produced in largest amounts by the mycorrhizal fungi was thiamin.In general more actinomycetes isolated from the rhizosphere than from the root free soil produced B-group vitamins. This was particularly true for thiamin.The amount of vitamins produced was higher in actinomycetes than the amounts produced by the mycorrhizal fungi.This research was carried out under problem MR.II. 16 coordinated by the Institute of Dendrology, Polish Academy of Sciences.     

Diversity and exploration of bioactive marine actinomycetes in the Bay of Bengal of the Puducherry coast of India

The present study was designed to investigate the Puducherry coast of the Bay of Bengal, India for the diversity of bioactive actinomycetes. A total of 50 actinomycete strains were isolated from the marine sediments and most of the strains were belongs to Streptomyces. These strains were identified by means of morphological physiological, biochemical and cultural characteristics. The isolates were subjected to shake flask fermentation and the secondary metabolites were extracted with ethyl acetate and screened for cytotoxicity, hemolytic activity and antimicrobial activity against selected bacterial and fungal pathogens. The cytotoxic activity was evaluated using HeLa cell lines by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole (MTT) assay, hemolytic activity on mouse erythrocytes and the antifungal activity was evaluated by MTT cytotoxic assay against Aspergillus niger, Aspergillus fumigatus and Candida albicans. The antibacterial activity was studied against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae. The cytotoxicity and antimicrobial activity of secondary metabolite was found to be concentration dependent and nearly 24% of isolates showed significant antimicrobial, hemolytic and cytotoxic activity. The results of our study indicate the diversity and bioactive potential of marine actinomycetes isolated in the Puducherry coast.     

Isolation of facultatively aerobic actinomycetes from the gut, parent soil and mound materials of the termites Procubitermesaburiensis and Cubitermes severus

Abstract Isolates of the genus Streptomyces were readily obtained from the intestines of two African species of soil-feeding termites by an aerobic explant technique using starch casein medium, and from their parent soil and mound materials by dilution plating. Discriminant analysis of the isolates, based on 44 representative characters, showed that the population derived directly from the termites was significantly different from that of the feed soil or the mound. The termite gut was considered to be a good source of unusual actinomycetes, but strains isolated under aerobic conditions are likely to be allochthons selected by the intestinal environment, which is highly alkaline and anaerobic. An anaerobic, filamentous isolate was obtained which may be a component of the prokaryotic symbiont population mediating termite digestion.     

Extramatrical structures of hydrophobic and hydrophilic ectomycorrhizal fungi

The extramatrical mycelia of Suillus bovinus, Rhizopogon luteolus and R. vinicolor, all examples of hydrophobic (ho), mat-forming mycorrhizal fungi, were examined while associated with their hosts in the unsterilized rhizoscope, and efforts were made to produce and examine similar structures in vitro. Comparisons were made with four hydrophilic (hi) mycorrhizal fungi, Thelephora terrestris, Cenococcum geophilum, Laccaria laccata and Hebeloma crustuliniforme. The ho fungi formed linear structures (coarse, rhizomorph-like cords, with vessels in the center) and fans, both in the rhizoscope and in vitro. The same was seen in mycorrhizal mycelia in forest soils. These cords did not themselves give rise to the fans peripherally, and were not proper rhizomorphs, but were created continuously from single exploring air hyphae in the preexisting fan. Thus the ho exploring hyphae aggregated into strands, which grew in thickness only when no suitable, exploitable substrate was found. The assembly of hyphae creating ho cords was seen in the air as well as on inert hydrophilic (glass) or hydrophobic (plastic) surfaces, but never in water. It is hypothesized that the ho cell wall surface glues hyphae together while cords are formed. Water disturbed strands and mantles already formed. The ho exploring hyphae could also create ho mycelial patches (as in a mat) at the water-air interface of a number of substrates. The periphery of these patches seemed to be composed of shorter exploiting hyphae penetrating different water-soaked substrates. Exploring, aerial hyphal tips of the ho fungi were shown to excrete water droplets from openings in the ho cell wall surface, both in vitro and in the rhizoscope. In the rhizoscope, droplet excretion was apparently directly governed by photosynthesis in the shoot of the seedling. It is proposed that the drop exudation represents a kidney-like function of the extramatrical hyphae and a bridge to drier soil particles to initiate nutrient uptake by the hyphae. The ecological function of the different extramatrical structures of ho fungi are discussed. The ho cords or hyphae may translocate water only in the vessels or symplastically and not in the cell walls. The ho property may be essential among the S-selected (stress-tolerant) factors in these forest fungi. The transfer from water-repelling exploring structures into more hi exploiting structures in water contact with surrounding soil debris is, therefore, of great importance. The hi fungi did not form rhizomorph-like strands, in most cases, but an extending hyphal mycelium, representing foraging, exploring and exploiting structures at the same time. In the field, short strands may be found. On the hi fungi droplets were also produced but readily fused into a water sheath around the hypha. The hyphae thus tended to wick water via the cell wall.     

Comparison of microbial numbers in soils by using various culture media and temperatures

The influence of different media and incubation temperatures on the quantification of microbial populations in sorghum, eucalyptus and forest soils was evaluated. Microbial growth was compared by using complex (tryptone soybean agar, TSA, casein-starch, CS, and Martin) and saline (Thorton, M3, Czapeck) media and incubation temperatures of 25 and 30 degrees C. Higher numbers of total bacterial and fungal colony-forming units (CFU) were observed in sorghum soils, and of spore-forming and Gram-negative bacteria in forest soils than other soils. Actinomycetes counts were highest in forest soil when using CS medium at 30 degrees C and in sorghum soil at 25 degrees C in M3 medium. Microorganism counts were dependent on the media and incubation temperatures. The counts at temperatures of 30 degrees C were significantly higher than at 25 degrees C. Microbial quantification was best when using TSA medium for total and spore-forming bacteria, Thorton for Gram-negative bacteria, M3 for actinomycetes, and Martin for fungi.     

Diel distribution patterns of fishes in a temperate large lowland river

During the day, juveniles and typical inshore species in the lower Oder River, Germany, inhabited the littoral (0·05–1·50 m deep) while potamal species inhabited the mid‐channel (40–100 m from the banks). During the night, two behavioural groups were distinguished: 1) potamal species and large individuals of other species, moved from offshore to the littoral, and 2) nocturnal foraging species, became active and increased in inshore and offshore habitats. Inshore, the most significant differences at night was the increasing density of silver bream Blicca bjoerkna increasing both total biomass and total length of fishes caught. Offshore, the increasing density of whitefin gudgeon Gobio albipinnatus at night was most significant. Additional night electrofishing improved the assessment of the abundance, age and size structure of typical potamal fish species. It should be incorporated in large river fish monitoring programmes.     

Study of the diversity of culturable actinomycetes in the North Pacific and Caribbean coasts of Costa Rica

In this study, 137 actinomycetes were isolated from subtidal marine sediments in the North Pacific and Caribbean coasts of Costa Rica. Bioinformatics analysis of the 16S rRNA gene sequences assigned the isolates to 15 families and 21 genera. Streptomyces was the dominant genus while the remaining 20 genera were poorly represented. Nearly 70% of the phylotypes presented a coastal-restricted distribution whereas the other 30% were common inhabitants of both shores. The coastal tropical waters of Costa Rica showed a high diversity of actinomycetes, both in terms of the number of species and phylogenetic composition, although significant differences were observed between and within shores. The observed pattern of species distribution might be the result of several factors including the characteristics of the ecosystems, presence of endemic species and the influence of terrestrial runoff. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Mosquitoes and West Nile virus along a river corridor from prairie to montane habitats in eastern Colorado

We conducted studies on mosquitoes and West Nile virus (WNV) along a riparian corridor following the South Platte River and Big Thompson River in northeastern Colorado and extending from an elevation of 1,215 m in the prairie landscape of the eastern Colorado plains to 1,840 m in low montane areas at the eastern edge of the Rocky Mountains in the central part of the state. Mosquito collection during June‐September 2007 in 20 sites along this riparian corridor yielded a total of 199,833 identifiable mosquitoes of 17 species. The most commonly collected mosquitoes were, in descending order: Aedes vexans, Culex tarsalis, Ae. dorsalis, Ae. trivittatus, Ae. melanimon, Cx. pipiens, and Culiseta inornata. Species richness was higher in the plains than in foothills‐montane areas, and abundances of several individual species, including the WNV vectors Cx. tarsalis and Cx. pipiens and the nuisance‐biter and potential secondary WNV vector Ae. vexans, decreased dramatically from the plains (1,215‐1,487 m) to foothills‐montane areas (1,524‐1,840 m). Ae. vexans and Cx. tarsalis had a striking pattern of uniformly high abundances between 1,200‐1,450 m followed by a gradual decrease in abundance above 1,450 m to reach very low numbers above 1,550 m. Culex species were commonly infected with WNV in the plains portion of the riparian corridor in 2007, with 14 of 16 sites yielding WNV‐infected Cx. tarsalis and infection rates for Cx. tarsalis females exceeding 2.0 per 1,000 individuals in ten of the sites. The Vector Index for abundance of WNV‐infected Cx. tarsalis females during June‐September exceeded 0.5 in six plains sites along the South Platte River but was uniformly low (0–0.1) in plains, foothills and montane sites above 1,500 m along the Big Thompson River. A population genetic analysis of Cx. tarsalis revealed that all collections from the ≈190 km riparian transect in northeastern Colorado were genetically uniform but that these collections were genetically distinct from collections from Delta County on the western slope of the Continental Divide. This suggests that major waterways in the Great Plains serve as important dispersal corridors for Cx. tarsalis but that the Continental Divide is a formidable barrier to this WNV vector.     

Contribution of the mesophilic fungi of different spices in Egypt

Thirty-eight genera and 81 species of fungi were isolated and identified from 120 samples of 24 kinds of spices collected from different places at Assiut Governorate, Egypt. Predominant genera wereAspergillus (25 species) andPenicillium (7 species) of whichA. flavus, A. niger, A. ochraceus, A. fumigatus, A. flavus var.columnaris, A. terreus, P. chrysogenum andP. corylophilum were the most commonly occurring.     

Euhydrophyte communities of the River Nile and its impoundments in Egyptian Nubia

The River Nile and its two impoundments, the Aswan Reservoir and Lake Nasser, are important habitats for submerged and floating-leaved freshwater macrophytes (euhydrophytes) in the desert region of Egyptian Nubia. Ordination and classification analysis of survey data collected during the period 1980–1986 suggested that the Aswan High Dam forms a man-made vegetational boundary, delineating two basic macrophyte community types. In Lake Nasser a community dominated by Najas spp. is present. In the Aswan Reservoir and the R. Nile downstream of the old Aswan Dam the euhydrophyte community is dominated by a Potamogeton crispus — Ceratophyllum demersum association. Differences between the two community types appear to be related to differences in physical factors (e.g. water level fluctuation and flow regime), and water chemistry, to phenological factors, and to the differing successional ages of the macrophyte communities of the Nile system upstream and downstream of the Aswan High Dam. There is some evidence for depth zonation of the submerged macrophyte community in both lake and river habitats. Strategy analysis of the euhydrophyte communities present upstream and downstream of the High Dam, over the period 1963–89, indicated that successful established-phase strategy types were similar on both sides of the dam. In the long term there seems little to prevent euhydrophyte species at present confined to below the High Dam from crossing this boundary to colonise Lake Nasser.     

Effect of soil fumigation with vapam on the dynamics of soil microflora and their related biochemical activity

Summary Fungal propagules, in general, were drastically reduced in vapam amended soils. The toxicant from 250 to 1000 ppm was lethal toFusarium spp. Only in the early part of the experiment, higher concentrations of vapam appreciably reduced the population of bacteria and actinomycetes, though later on, their population gradually increased. The numbers of Azotobacter in soil amended with 125, 250 and 500 ppm did not alter appreciably, but their population in treated soils increased over the check on the 45th day. All concentrations of vapam lowered the population of Rhizobia.Vapam produced inhibitory effect on soil nitrification, inhibition period varying with the amount of chemical applied initially. Vapam from 125 to 500 ppm stimulated the ammonification process, while its higher concentration (1000 ppm) produced detrimental effect for 15 days. The toxicant increased CO₂ production for first 32 days.Results suggest that extraordinary success of vapam in controlling soil-borne infections of Pythium and Rhizoctonia was not entirely due to its fungicidal action. Partly it was also due to an increase in the population of known antagonists of these pathogens in fumigated soils.     

Prevalence of fungi in carpeted floor environment: analysis of dust samples from living-rooms,bedrooms, offices and school classrooms

The results of 100 carpet dust analyses from atopic individuals' environment were compared according to the sampling period or the location. Dust samples were collected with a standard domestic vacuum cleaner, in locations with carpeted floor: in residences (living-room and/or bedroom), in school classrooms and in offices. The quantities of fungi vary from 5000 CFU/g to 66 000 000 CFU/g of dust. More than 100 species were isolated by dilution plating. The main species found in carpet dust wereEurotium repens, Penicillium chrysogenum, Alternaria alternata, Aureobasidium pullulans andPhoma herbarum. Strict xerophilic species were rather rare and detected in small quantities. Differences in the distribution of the CFU concentrations were examined for the four different sampling locations and were statistically significant (P=0.0174). In this study, schools were open spaces, and offices, mostly with air conditioning systems, were locations in which air is not confined. This, added to frequent professional carpet cleaning, probably explains the lowest levels of fungal concentration found in these locations. The majority of the homes had the largest fungal concentration in the living-room (median: 2×10⁵ CFU/g) while some bedrooms (median: 7×10⁴ CFU/g) had the highest concentrations. It is suggested that, when fungi are suspected to be the origin of respiratory allergy or irritating symptoms, the mycoflora of the bedroom, principally, should be investigated first.     

Prevalence of fungi in carpeted floor environment: Analysis of dust samples from living-rooms,bedrooms, offices and school classrooms

The results of 100 carpet dust analyses from atopic individuals' environment were compared according to the sampling period or the location. Dust samples were collected with a standard domestic vacuum cleaner, in locations with carpeted floor: in residences (living-room and/or bedroom), in school classrooms and in offices. The quantities of fungi vary from 5000 CFU/g to 66 000 000 CFU/g of dust. More than 100 species were isolated by dilution plating. The main species found in carpet dust wereEurotium repens, Penicillium chrysogenum, Alternaria alternata, Aureobasidium pullulans andPhoma herbarum. Strict xerophilic species were rather rare and detected in small quantities. Differences in the distribution of the CFU concentrations were examined for the four different sampling locations and were statistically significant (P=0.0174). In this study, schools were open spaces, and offices, mostly with air conditioning systems, were locations in which air is not confined. This, added to frequent professional carpet cleaning, probably explains the lowest levels of fungal concentration found in these locations. The majority of the homes had the largest fungal concentration in the living-room (median: 2×10⁵ CFU/g) while some bedrooms (median: 7×10⁴ CFU/g) had the highest concentrations. It is suggested that, when fungi are suspected to be the origin of respiratory allergy or irritating symptoms, the mycoflora of the bedroom, principally, should be investigated first.