Comparison of fungal communities among ten macrophyte rhizospheres

The fungal community composition, size and several physico-chemical properties were individually investigated in ten macrophyte rhizospheric substrates using nested PCR-denaturing gradient gel electrophoresis and soil chemical methods. Results indicated that both Dothideomycetes and Sordariomycetes were dominant fungi in macrophyte rhizospheric substrates, and denitrifying fungi (Fusarium graminearum) was found in nine of ten macrophyte rhizospheres. Fungal Shannon-Wiener diversity index (H) and richness (S) in Thalia dealbata, Typha latifolia, Iris hexagona and Hemerocallis aurantiaca rhizospheres were higher than those in other six rhizospheres. Fungal number and biomass were 1.91 × 10³ CFUs g^?1 dw and 1.53 μg ergosterol g^?1 dw in Iris pseudacor rhizosphere, and were greater than in other nine rhizospheres. The correlation analysis showed that fungal number and biomass significantly and positively correlated to total soil phosphorus, while fungal H and S were significantly and negatively correlated to total organic carbon. The principal components analysis (PCA) showed that the fungal community significantly divided ten macrophyte rhizospheres into four groups, showing the significant difference of fungal communities among ten rhizospheric substrates. The current study revealed for the first time the importance of rhizospheric fungal community in distinguishing macrophyte rhizospheres, thus will undoubtedly widen our insight into fungal communities in aquatic rhizospheres.     

Assessment of indoor climate in an apartment by use of a fungal index.

Indoor climate was assessed in an apartment in Isehara City, Kanagawa Prefecture, Japan, by use of a fungal index. The index represents the environmental (climate) capacity to allow fungal growth; it is determined by measuring the growth rate of a biosensor fungus, Eurotium herbariorum J-183. Differences in climate among various parts of the apartment (microclimate) and its changes could be clarified by using the index. The index in the entire apartment was high in summer, low in winter, and intermediate in spring and autumn. According to the part of the apartment, the index was high in water-associated areas and cool areas. This high fungal index in cool areas was caused by the air at the same absolute humidity showing an increase in the relative humidity with a decrease in temperature. Fungal contamination rapidly progressed in areas with a high fungal index in this apartment. A correlation was observed between the fungal index and fungal contamination. Therefore, areas susceptible to fungal contamination can be estimated by use of the fungal index.     

肝硬化患者无菌腹水中真菌DNA的检测及易位研究

目的检测和分析肝硬化患者无菌腹水中真菌DNA存在状况。方法选取118例无菌腹水的肝硬化患者为研究对象,分别采集患者刚入院时的腹水、血液和粪便标本。应用PCR技术直接检测标本的真菌DNA并克隆测序。并收集患者临床资料,对患者临床症状及检验结果进行分析比较。结果1名患者的腹水、血液、粪便中同时检测到真菌DNA,14名患者的腹水和粪便中同时检测到真菌DNA,3名患者的血液和粪便中同时检测到真菌DNA,大部分序列间的相似性高于99％。测序检测到最多的菌种为Candidaalbicans。结论肝硬化患者无菌腹水中能够检测到真菌DNA,并且提示在肝硬化患者腹水和血清中检测到的真菌DNA易位于肠道。     

电子废弃物拆解区土壤重金属污染对丛枝菌根真菌多样性的影响

【背景】电子废弃物拆解造成的土壤重金属污染引发的环境问题日益突出,丛枝菌根(arbuscular mycorrhizal,AM)真菌能侵染植物根系并增强植物抵御环境胁迫的能力,具有重要的生态功能和应用潜力。【目的】探究电子废弃物拆解区土壤重金属污染对AM真菌群落结构与多样性的影响,甄别可耐受重金属污染的AM真菌类群。【方法】从浙江台州某典型电子废弃物拆解场地及其周边区域共采集土壤样品12份,针对土壤中AM真菌的18S rRNA基因进行高通量测序以及可操作分类单元(operational taxonomic unit,OTU)相对丰度和多样性指数计算。【结果】该区土壤中AM真菌由原囊霉目(Archaeosporales)、球囊霉目(Glomerales)和多孢囊霉目(Diversisporales)组成,其中球囊霉目占据优势地位。土壤AM真菌多样性指数与重金属的浓度、综合污染指数和潜在生态风险指数间均无显著相关性,但疑似泡囊根生囊霉(Rhizophagus vesiculiferus)的OTU相对丰度与上述重金属污染指标之间均呈显著正相关关系。【结论】R. vesiculiferus可能对重金属污染有极强耐受性,可为今后电子废弃物拆解污染土壤治理提供技术基础。     

An improved method of eliminating fungal contamination from monolayer cell cultures

A method is described for eliminating fungal and other forms of contamination from valuable monolayer cell cultures. The method employs the following sequence of operations: several changes of medium, trypsinization and removal of cells to coverglasses in appropriate tubes with medium plus amphotericin B (Fungizone) or other antibiotic, removal of coverglasses to new tubes with medium plus antibiotic, and removal in a few days to a new culture vessel without antibiotic. If microorganisms do not show up in 3–5 days, they have been eliminated. Greater success is achieved by using the same method with coverglass fragments in small culture wells.     

CARD9突变在真菌感染性疾病中的研究进展

胱天蛋白酶募集域蛋白 9(caspase recruitment domain-containg protein 9，CARD9)属于 CARD 家族中的一员，存在于脾、肝、胎盘、肺、脑等人体多种组织中，是高度表达于中性粒细胞、巨噬细胞及树突细胞等髓系细胞中的一个重要衔接蛋白。CARD9可与Bcl-10、黏膜相关淋巴组织淋巴瘤转运蛋白1(mucosa-associated lymphoid tissue lymphoma translocation protein 1，MALT-1)结合并形成CARD9-Bcl-10-MALT-1(CBM)复合体，作为C型凝集素受体(C-type lectin receptor，CLR)等通路的重要媒介，激活核因子κB(nuclear factor κB，NF-κB)等炎症信号通路，在抗真菌免疫中发挥重要作用。迄今为止，全世界已报道14个国家共56例患者发生18种CARD9突变的报道，真菌类型涉及念珠菌、皮肤癣菌、暗色真菌及曲霉等。本文针对CARD9突变在不同真菌感染性疾病中的研究进展进行综述。     

Changes in fungal community of Scots pine (Pinus sylvestris) needles along a latitudinal gradient in Sweden

Conifer needles are typically long lived and can host a diverse community of fungal species with various effects on their host tree. The purpose of this study was to analyse shifts in the fungal community of Scots pine (Pinus sylvestris) needles on different spatial scales using 454 pyrosequencing. The fungal community composition changed gradually along a north-south gradient through Sweden, representing boreal to temperate vegetation zones. OTU richness and Shannon's diversity index increased with increasing latitude, but only in naturally regenerated forests. On the tree level, needles with symptoms of disease hosted a more diverse mycobiota compared to healthy needles, presumably supporting more pathogenic or saprotrophic species. This study provides a better insight into the patterns of fungal communities of Scots pine needles and highlights the need for further experimental research to identify specific environmental factors shaping the abundance of different fungal species.     

Airborne fungal spores in an industrial area: seasonal and diurnal periodicity

Qualitative and quantitative studies of atmospheric fungal spores at a chloralkali factory, Jayashree Chemicals. were made during 1993 employing culture plate and rotorod methods. A total of 57 sporulating fungal types, including three sterile mycelial forms, were recorded by the culture plate method and 51 spore types, including the hyphal fragments and unidentified spores, were recorded by the rotorod method. As to the seasonal variation, winter was found to be the greatest contributor of fungal spores as compared to the summer and rainy season. Instead, when considering the hour of the day, the peak number of fungal propagules was recorded at noon (12.00 h) followed by evening and morning values, an exception being recorded in winter months, when maximum CFUs ofCladosporium were monitored in the morning. The seasonal variation in fungal concentration and composition was found to be influenced by temperature, rainfall and relative humidity, whereas diurnal incidence was the effect of varying temperature and relative humidity during day time only. Moderate temperature and relative humidity favoured the maximum fungal spore load in the atmosphere.Cladosporium, Nigrospora, Alternaria, Lasiodiplodia, Drechslera, Pestalotia, Curvularia, Epicoccum, Aspergillus, Penicillium andChaetomium were the commonest fungal spores in the factory area.     

Analysis of fungal community structure in the soil of Zoige Alpine Wetland

To understand the soil fungal community diversity in different zones of the Zoige Alpine Wetland, BIOLOG analysis and traditional culture method were employed in our research. Three sample sites namely the Conservatory Station up-hill slope (CSUS), the Flower Lake side (FLS) and the Conservatory Station down slope (CSDS) with increasing by water content were investigated. The results of BIOLOG showed that fungal catabolic richness index (S) and Shannon diversity index (H) increasingly rose with water content augmented from CSUS to CSDS, while different from the former tendency, the fungal catabolic activity was highest at CSDS and lowest at FLS. Principal component analysis (PCA) results demonstrated the functional diversity of fungal community varied among the three sample sites, showing us more similarity between CSDS and FLS, and considerable difference between CSUS and the former two sites. The outcome of traditional culture method illustrated the number of soil fungi increased from CSUS to CSDS, while the sort of fungal species that could be cultured did not show much difference among the three sample sites.     

Analysis of fungal community structure in the soil of Zoige Alpine Wetland

To understand the soil fungal community diversity in different zones of the Zoige Alpine Wetland, BIOLOG analysis and traditional culture method were employed in our research. Three sample sites namely the Conservatory Station up-hill slope (CSUS), the Flower Lake side (FLS) and the Conservatory Station down slope (CSDS) with increasing by water content were investigated. The results of BIOLOG showed that fungal catabolic richness index (S) and Shannon diversity index (H) increasingly rose with water content augmented from CSUS to CSDS, while different from the former tendency, the fungal catabolic activity was highest at CSDS and lowest at FLS. Principal component analysis (PCA) results demonstrated the functional diversity of fungal community varied among the three sample sites, showing us more similarity between CSDS and FLS, and considerable difference between CSUS and the former two sites. The outcome of traditional culture method illustrated the number of soil fungi increased from CSUS to CSDS, while the sort of fungal species that could be cultured did not show much difference among the three sample sites.     

Oxygen consumption-based evaluation of fungal activity

A novel oxygen-based microplate assay for studying fungal activity is described. Fungal activity results in a change of oxygen concentration in CVC-96 plates^® and thus produces a signal that enables continuous monitoring of fungal activity. In this study the oxygen consumption was different for three tested fungi, Fusarium oxysporum f. sp. lycopersici, Verticillium dahliae and Trichoderma longibrachiatum. The assay described is a highly sensitive and reliable method for monitoring fungal activity. This assay does not interfere with fungal development and there is no need to kill the cells to take a measurement. This test would be useful for studying reactions that consume oxygen so possible applications of this test could be physiological studies, testing of fungicidal or fungistatic compounds, and studying enzyme reactions. The system provides a valuable insight into the kinetics of fungal activity and is suitable to test other systems.     

Susceptibility of phosphogypsum to fungal growth and the effect of various biocides

Natural gypsum (NG) and phosphogypsum (PG) were tested for resistance to fungal growth based on standard test ASTM D 3273-86, with the recommended mixture of three fungal species, and using the same test modified by the use of a Cladosporium sp. A, isolated from a gypsum plaster ceiling. In the standard test little growth occurred on any of the test specimens. However, abundant fungal growth was produced by the Cladosporium sp. A on phosphogypsum, which was much more susceptible than natural gypsum. Phosphogypsum heated to 600°C to destroy organic residues was resistant to growth of Cladosporium sp. A, as well as other fungi isolated from phosphogypsum panels stored in the environment for 2 years: Cladosporium sp. B, Aspergillus niger and Trichoderma sp. Phosphogypsum moulded in Petri dishes was susceptible to growth of a wide range of fungi, although Fusarium sp. and Rhizopus sp. caused practically no discoloration of the substrate. Six biocides were separately incorporated into the phosphogypsum at concentrations recommended by the suppliers and test specimens incubated on Sabouraud agar inoculated with various fungal isolates. The biocide 2-N-octyl-4-isothiazolin-3-one was the most efficient compound. It prevented the growth of the fungi most likely to cause health problems in buildings, but not that of Helminthosporium sp., isolated from powdered phosphogypsum in the factory. This was the most resistant fungus showing growth on all biocide-containing specimens.     

Diversity of soil fungal communities of Cerrado and its closely surrounding agriculture fields

Cerrado is a savanna-like region that covers a large area of Brazil. Despite its biological importance, the Cerrado has been the focus of few microbial diversity studies. A molecular approach was chosen to characterize the soil fungal communities in four areas of the Cerrado biome: a native Cerrado, a riverbank forest, an area converted to a soybean plantation, and an area converted to pasture. Global diversity of fungal communities in each area was assessed through Ribosomal intergenic spacer analysis which revealed remarkable differences among the areas studied. Sequencing of approximately 200 clones containing 18S rDNA sequences from each library was performed and, according to the genetic distance between sequences, these were assigned to operational taxonomic units (OTUs). A total of 75, 85, 85, and 70 OTUs were identified for the native Cerrado, riverbank forest, pasture, and soybean plantation, respectively. Analysis of sequences using a similarity cutoff value of 1% showed that the number of OTUs for the native Cerrado area was reduced by 35%; for the soybean plantation, a reduction by more than 50% was observed, indicating a reduction in fungal biodiversity associated with anthropogenic activity. This is the first study demonstrating the anthropogenic impact on Cerrado soil fungal diversity.     

Initial fungal colonizer affects mass loss and fungal community development in Picea abies logs 6 yr after inoculation

Picea abies logs were inoculated with Resinicium bicolor, Fomitopsis pinicola or left un-inoculated and placed in an old-growth boreal forest. Mass loss and fungal community data were collected after 6 yr to test whether simplification of the fungal community via inoculation affects mass loss and fungal community development. Three techniques were used to survey communities: (1) observation of fruiting structures; (2) culturing on media; and (3) cloning and sequencing of ITS rDNA. Fruit body surveys detected the smallest number of species (18, 3.8 per log), DNA-based methods detected the most species (72, 31.7 per log), and culturing detected an intermediate number (23, 7.2 per log). Initial colonizer affected community development and inoculation with F. pinicola led to significantly greater mass loss. Relationships among fungal community composition, community richness and mass loss are complex and further work is needed to determine whether simplification of fungal communities affects carbon sequestration in forests.     

Mycoflora and Occurrence of Aflatoxin B 1 in Dried Yam Chips from Markets in Ogun and Oyo States,Nigeria

Seventy-six samples of dried yam chips locally called elubo isu were purchased in 2000 from markets in Ogun and Oyo States of southwestern Nigeria. The samples were assessed for pH, moisture content, associated fungi and aflatoxin B1 contamination. The pH of samples ranged from 5.6 to 6.1,while the moisture contents varied from 6.8 to 14.5% in Ogun samples, and 7.1 to 13.6% in samples from Oyo. Aspergillus and Penicillium were the two prevalent genera of fungi, and the number of colony forming units per gram of these two genera in the yam chips studied exceeded the tolerance limit in foodstuffs. The other fungal genera isolated included Botryodiplodia, Cladosporium, Fusarium, Rhizopus, Mucor, Aureobasidium and Paecilomyces. The two most frequent fungal species were A. niger and A. flavus. Thin layer chromatographic analysis showed that 17 samples or 22% contained aflatoxin B1 beyond the detection limit (5 ppb), but only three samples or 4% had toxin level above 30 ppb, the tolerance level in food for human consumption. The mean concentration of aflatoxin B1 in positive samples was 27.1 ppb.     

工业有机污染对小型水体沉积物真菌群落的影响分析

【背景】有机污染对水体沉积物中的微生物多样性影响极大,而目前有关污染水体沉积物中真菌多样性的研究较少。【目的】研究不同程度有机污染下水体沉积物中真菌种群的多样性特征,探究工业有机污染对真菌群落的影响。【方法】应用化学分析方法和高通量测序技术进行研究,并分析水质、沉积物成分等环境因子与沉积物真菌多样性的相关性。【结果】随着污染程度的降低,水体沉积物中真菌序列数、OTU数和Shannon多样性指数均呈上升趋势。未分类真菌、子囊菌门和担子菌门是沉积物真菌群落中的主要优势种类,主要优势属为Zopfiella、Westerdykella、Clypeosphaeria、Ilyonectria、Paracremonium、Aspergillus。真菌Shannon指数与水体溶解氧(dissolvedoxygen,DO)极显著正相关,与沉积物有机质和总磷含量显著负相关,Simpson指数与水体总氮(total nitrogen,TN)、氨氮(NH3-N)、总磷(total phosphorus,TP)显著相关。【结论】有机污染导致水体溶解氧下降和沉积物有机质增加,从而导致污染区真菌多样性显著下降。Zopfiella、Penicillium、Emericellopsis、Westerdykella、Jugulospora、Chromelosporium可能参与曝气处理区域沉积物兼氧条件下污染物的去除,Ilyonectria、Mortierella、Epicoccum可能主要参与水生生物残体分解、污染物的吸附沉降等过程。     

Linking wood-decay fungal communities to decay rates: Using a long-term experimental manipulation of deadwood and canopy gaps

Decomposition transfers carbon (C) from detrital organic matter to soil and atmospheric pools. In forested ecosystems, deadwood accounts for a large proportion of the detrital C pool and is primarily decomposed by wood-inhabiting fungi (WIF). Deadwood reductions linked to forest harvesting may alter WIF richness and composition, thus indirectly influencing the persistence of deadwood and its contribution to C and nutrient cycling. Forest structure was enhanced via canopy gap creation and coarse woody debris (CWD) addition that mimic natural disturbance by windfall within a deciduous northern hardwood forest (Wisconsin, USA) to examine its effect on deadwood-associated biodiversity and function. Experimental sugar maple (Acer saccharum) logs were sampled, for DNA extraction, ten years after placement to determine the assembly of fungal community composition and its relationship to wood decay rates.Our findings suggest that the WIF community responded to gap disturbance by favoring species able to persist under more extreme microclimates caused by gaps. CWD addition under closed canopy tended to favor a different species assemblage from gap creation treatments and the control, where canopy was undisturbed and CWD was not added. This was presumably due to consistent microclimatic conditions and the abundance of CWD substrates for host specialists. Fungal OTU richness was significantly and inversely related to CWD decay rates, likely due to competition for resources. In contrast, fungal OTU composition was not significantly related to CWD decay rates, canopy openness or CWD addition amounts. Our study site represents a diverse fungal community in which complex interactions among wood-inhabiting organisms and abiotic factors are likely to slow CWD decomposition, which suggests that maintaining a biodiverse and microsite-rich ecosystem may enhance the capacity for C storage within temperate forests.     

Airborne fungal load in agricultural environment during threshing operations

The effect of threshing operations on the fungal spora of farm air, has been studied with the culture plate method. Air samples were taken before, during and after the threshing of paddy and wheat grains, at the end of the respective crop seasons. An immediate local increase in the airborne fungal load was observed during threshing operations. In case of wheat the high rise was due toAlternaria tenuissima, followed byDrechslera sp. andCladosporium herbarum. In Boro variety of paddy, the high count was contributed byAlternaria humicola andA. tenuissima, while in Aman variety,Helminthosporium oryzae was the dominant type followed byC. herbarum and unidentified yeasts.Aspergillus spp. were observed in significant numbers before the operation started; their occurrence was negligible during threshing. A considerable number of yeast was observed, particularly during threshing and after threshing operations.