Emericella qinqixianii, a new species from desert soil in China

Emericella qinqixianii, a new species isolated from desert soil from Sanchakou, Aksu, Qiemo, Yuli, Yutian, and the Taklimakan desert 100 km inland from Minfeng, Xinjiang Province, China, is described and illustrated. It is characterized by grayish yellow to olive brown, non-ostiolate ascomata surrounded by hyaline to pale yellowish brown hülle cells, membranaceous peridium, prototunicate asci, and violet-brown, lenticular ascospores with two equatorial crests, smooth convex surfaces, and long filiform appendages. It hasAspergillus anamorph with biseriate aspergilla.     

A new species of Gigaspora from desert soils of Rajasthan,India

A new species of the endogonaceous fungus Gigaspora, isolated from the Indian semi-arid region, is described. The fungus, named G. tuberculata, produces rusty-brown azygospores with septate subtending hypha. The azygospores bear warts all over the outer wall. The shape, size and general appearance of these spores resemble those of Scutellospora persica.Neeraj and A.K. Varma are with the Microbiology Unit, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067, India; K.G. Mukerji is with the Applied Mycology Laboratory, Botany Department, University of Delhi, Delhi 110 006, India. B.C. Sharma is with the Department of Textile Engineering, Indian Institute of Technology, New Delhi 110 016, India.     

Some interesting species of Emericella and Aspergillus from Egyptian desert soil

Emericella desertorum Samson et Mouchacca spec. nov. is described and illustrated. It differs from the other Emericella species by the large ascospores with low crests. An Aspergillus conidial state was not observed. Additional information on the morphology and physiology of Emericella fruticulosa (Raper et Fennell) Malloch et Cain and Aspergillus egyptiacus Moubasher et Moustafa is given. The osmophilic and halophilic properties occurring within the genus Aspergillus are discussed.     

Emericella omanensis,a new species from Oman soil

A new species ofEmericella isolated from forest soil in the Oman,E. omanensis, is described and illustrated. It differs from the other known species of the genus in having bivalvate ascospores with a tuberculate or verruculose convex wall. The new species is compared with the closely related speciesE. desertorum andE. echinulata.     

Emericella appendiculata, a new species from Chinese soil

Emericella appendiculata, a new species isolated from soil of the Pamire Plateau, is described and illustrated. It is characterized by grayish green non-ostiolate ascomata surrounded by a thick layer of hülle cells, membranaceous peridium, prototunicate asci, violet-brown, lenticular ascospores which are ornamented by two stellate equatorial crests, capitate convex surfaces, and long filiform appendages, and anAspergillus anamorph with biseriate conidiogenous cells.     

Isolation of zoosporogenous actinomycetes from desert soils

We have undertaken a study to estimate the species diversity of zoosporogenous actinomycetes that can be isolated from an arid environment. The study site encompassed an area of approximately 22 000 square kilometers of the Mojave Desert along the California-Nevada border. A series of 29 soil samples was collected along two intersecting transects of approximately 190 and 240 km which traversed a number of distinct ecosystems. A₀ horizon soils were collected from the rhizosphere of the predominant vegetation at each sampling site and screened for the target genera using selective isolation techniques: chemoattraction (xylose and -collidine) and baiting with hair. Following incubation of primary isolation plates for 28 days at 28°C, all colonies that exhibited filamentous growth, presence of sporangia and/or motile spores upon direct microscopic observation (450 and 1000×) were further characterized by fatty acid analysis (FAME). Most of the isolates fell into three broad clusters that roughly correlated with presumptive genus assignments. Individual isolates could be assigned to 226 FAME biotypes based on chromatographic similarity (85%). The dominant species (514/826 isolates) belong to a previously undescribed taxon that morphologically resemblesGeodermatophilus but possesses unique FAME profiles that include at least three novel lipids. The remainder of the isolates were species ofActinoplanes, indeterminate species or vagrant isolates ofStreptomyces.     

Four new species of Emericella from the Mediterranean region of Europe

Four new species of Emericella, E. discophora, E. filifera, E. olivicola and E. stella-maris, are proposed. Their new taxonomic status was determined applying a polyphasic taxonomic approach using phenotypic (morphology and extrolite profiles) and molecular (sequences of ITS, beta-tubulin and calmodulin genes) characters. Ascospores of E. stella-maris and E. olivicola have star-shape equatorial crests, those of E. filifera form long appendages that emerge radially from narrow stellate crests and those of E. discophora produce wide and entire, nonstellate equatorial crests. E. stella-maris originated from leaf litter in Tunisia and E. filifera from raisins in Argentina, and both of them also were found in hypersaline water of a saltern in Slovenia. E. olivicola was isolated from olives in Italy and E. discophora from soil in Spain. All listed species possess distinct extrolite profiles: E. stella-maris produced arugosin E, shamixanthone and the yet unelucidated metabolites glia 1-3; E. filifera produced shamixanthone and varitriols; E. discophora produced sterigmatocystin and versicolorins; E. olivicola produced numerous extrolites such as arugosin E, siderin, shamixanthone, sterigmatocystin, terrein, varitriols and aflatoxin B1, of which the latter was detected only in one of the two strains.     

Production of phosphatates by fungi isolated from desert soils

Twelve fungal cultures isolated from Indian desert soils belonging toAspergillus, Penicillium, Acrophialophora andAlternaria were found to produce both acid and alkaline phosphatases in liquid medium, their amounts varying from culture to culture. Maximum production of these enzymes was observed withA. niger. In general, acid phosphatase activity was much higher as compared to alkaline phosphatase. The optimum incubation period for the production of these enzymes was found to be 14 d and thereafter it started declining. There was a significant and positive correlation between biomass production and acid phosphatase activity but not with alkaline phosphatase.     

A new species of Poroconiochaeta from Russian soils

Poroconiochaeta tetraspora sp. nov., isolated from soil of Russia, is described and illustrated. The new taxon differs from P. discoidea in its four-spored asci (eight-spored in P. discoidea) and from P. punctulata in the pattern of ascospore ornamentation, which is conspicuously pitted in P. tetraspora (punctulate in the other species). The new combination Poroconiochaeta savoryi is proposed and discussed.     

A new species of Syspastospora from tropical soils

Syspastospora tropicalis sp. nov. isolated from soil samples from different tropical regions is described and illustrated. The fungus can be easily separated from the other species of the genus by its setose perithecial ascomata with a short papillate neck.     

农田土壤磷素淋溶及其预测

农田土壤磷的淋溶损失,不仅造成肥料利用率降低、农业生产成本上升,还能引起地下和地表水体富营养化。在综合大量中外文献的基础上,阐述了农田土壤磷素淋溶问题的提出、淋溶对水体富营养化的贡献、淋溶液中磷素的形态及其比例、影响土壤磷素淋溶的因子、淋溶机理、预测方法,并对农田土壤磷素淋溶及其预测作了展望。     

A new baseline of organic carbon stock in European agricultural soils using a modelling approach

Proposed European policy in the agricultural sector will place higher emphasis on soil organic carbon (SOC), both as an indicator of soil quality and as a means to offset CO₂ emissions through soil carbon (C) sequestration. Despite detailed national SOC data sets in several European Union (EU) Member States, a consistent C stock estimation at EU scale remains problematic. Data are often not directly comparable, different methods have been used to obtain values (e.g. sampling, laboratory analysis) and access may be restricted. Therefore, any evolution of EU policies on C accounting and sequestration may be constrained by a lack of an accurate SOC estimation and the availability of tools to carry out scenario analysis, especially for agricultural soils. In this context, a comprehensive model platform was established at a pan‐European scale (EU + Serbia, Bosnia and Herzegovina, Croatia, Montenegro, Albania, Former Yugoslav Republic of Macedonia and Norway) using the agro‐ecosystem SOC model CENTURY. Almost 164 000 combinations of soil‐climate‐land use were computed, including the main arable crops, orchards and pasture. The model was implemented with the main management practices (e.g. irrigation, mineral and organic fertilization, tillage) derived from official statistics. The model results were tested against inventories from the European Environment and Observation Network (EIONET) and approximately 20 000 soil samples from the 2009 LUCAS survey, a monitoring project aiming at producing the first coherent, comprehensive and harmonized top‐soil data set of the EU based on harmonized sampling and analytical methods. The CENTURY model estimation of the current 0–30 cm SOC stock of agricultural soils was 17.63 Gt; the model uncertainty estimation was below 36% in half of the NUTS2 regions considered. The model predicted an overall increase of this pool according to different climate‐emission scenarios up to 2100, with C loss in the south and east of the area (involving 30% of the whole simulated agricultural land) compensated by a gain in central and northern regions. Generally, higher soil respiration was offset by higher C input as a consequence of increased CO₂ atmospheric concentration and favourable crop growing conditions, especially in northern Europe. Considering the importance of SOC in future EU policies, this platform of simulation appears to be a very promising tool to orient future policymaking decisions.     

Plasmid incidence in bacteria from agricultural and industrial soils

Heavy metal contents of agricultural and industrial soils were determined by atomic absorption spectrophotometry. The analysis of the samples collected from two different locations revealed significantly high levels of Fe, Zn, Cu, Cr and Ni. Certain microbiological parameters (total aerobic heterotrophs, asymbiotic N₂-fixers, total Actinomycetes and fungi) were also monitored from these soils. A total of 70 bacterial isolates from agricultural and industrial soils were examined for plasmid DNA content and resistance to the antibiotics amoxycillin, cloxacillin, chloramphenicol, doxycycline methicillin, nalidixic acid, and tetracycline. Minimum inhibitory concentrations (MICs) of Cu, Cr, Pb, Cd, Hg, Zn, and Ni for each isolate were also determined. Resistance was most frequent to methicillin (48.5%), cloxacillin (45.7%), and nalidixic acid (40%) for all isolates of bacteria. The highest MICs observed were 100 g/ml for mercury, 800 g/ml for Ni and 1600 g/ml for other metals. The incidences of metal resistance and MICs of metals for bacteria from industrial soil were significantly different to those of agricultural soil. On a percentage basis, 91.4% of the total bacterial isolates from industrial soil were found to harbour plasmids whereas 40% of the isolates from agricultural soil contained plasmids.     

Thermotolerant and thermophilic actinomycetes from soils of Mongolia desert steppe zone

In the actinomycete complexes of Mongolian desert soils, thermotolerant and thermophilic actinomycetes were found in high abundance, exceeding that of the mesophilic forms. Among the thermotolerant members of the order Actinomycetales, Streptomyces, Micromonospora, Actinomadura, and Streptosporangium species were most widespread in desert soils. Experiments with soil microcosms demonstrated that thermophilic actinomycetes in desert soils grew, developed, and formed mycelia of the length comparable to that of the mesophilic forms of actinomycetes. Molecular biological investigation of the samples of desert steppe soils by denaturing gradient gel electrophoresis (DGGE) and fluorescent in situ hybridization (FISH) revealed members of the phylum Actinobacteria. FISH analysis revealed that the biomass of the metabolically active mycelial actinobacteria in the prokaryotic community of Mongolian desert soils exceeded that of the unicellular Actinobacteria.     

Environmental controls on nitric oxide emission from northern Chihuahuan desert soils

A survey of nitric oxide (NO) emission from Chihuahuan desert soils found mean NO fluxes <0.1 ng NO-N cm^–2h^–1 during the dry season. These fluxes were at thelower end of the range reported for temperate grassland and woodlandecosystems. NO fluxes from wet or watered soils were higher(0.1–35 ng NO-N cm^–2 h^–1).Watering of black grama grassland soils produced an initial pulse of 12ng cm^–2 h^–1 (12-h after 1-cm watering)with high fluxes sustained over 4 days with repeated watering. Initialpulses from shrubland soils were lower (maximum 5 ngcm^–2 h^–1), and fluxes declined withrepeated watering. Repeated watering of creosotebush soils depleted thesoil NH ₄ ⁺ pool, and NO emissions weredirectly related to soil NH ₄ ⁺ concentrationsat the end of the experiment. In watered andNH ₄ ⁺ -fertilized creosotebush soils, NO fluxeswere positively related to potential net nitrification rates.NH ₄ ⁺ -fertilization boosted the initial NOpulse 15 times in the shrubland and 5 times in black grama grasslandrelative to watered controls. These experimental results point towardgreater substrate limitation in shrublands. In this desert basin, NOemission averaged 0.12 kg N ha^–1 y^–1in untreated soil and 0.76 kg N ha^–1y^–1 in watered soil. We multiplied these averages bythe distribution of grassland and shrubland vegetation within a58,600-ha area of the Jornada del Muerto basin to estimate regionallosses of 0.15–0.38 kg NO-N ha^–1y^–1 for this area of the Chihuahuan desert.     

A new species from tropical soils,Eupenicillium tropicum

Forty-three strains of Eupenicillium tropicum sp. nov. were isolated from soils collected in India, Costa Rica and Galapagos, Ecuador. The species is characterized by biverticillate penicilli, slightly rough, subglobose to ovate conidia, brownish cleistothecia that become brown-gray with age, and ascospores with two equatorial flanges and slightly roughened valves. All strains produced a large number of indole alkaloids, and many types of unknown secondary metabolites with characteristic chromophores were produced by a majority of strains. Eupenicillium tropicum is morphologically most similar to E. shearii, but based on ITS-LSU sequences, is most closely related to Penicillium citrinum, P. sartoryi and P. westlingii. Eupenicillium shearii strains consistently produce paxillin, paspalinine and shearinins, while the latter three penicillia all produce citrinin consistently.