pH Influences the Distribution of Microbial Rock-Weathering Phenotypes in Weathered Shale Environments

Rock varnish is a darkly pigmented coating rich in manganese oxides. Though microbes inhabit varnish deposits, it is unclear whether they are involved in varnish formation. The fungal communities of rock varnish and adjacent rock sites with no visible varnish deposits were examined. Microcolonial fungi were identified at all sampling sites, and were associated with manganese oxides in patches of incipient varnish at non-varnish sites. Fungi were closely related to manganese-oxidizing genera and seventeen isolates oxidized manganese in culture, producing six distinct manganese-oxide morphologies. Our results indicate that microcolonial fungi may play a crucial role in rock varnish formation. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the free supplemental file.     

Succession of Fungi on Decaying Setaria glauca Beauv.: A Qualitative Analysis of the Mycoflora

The mycoflora recorded on the decaying shoots of Setaria glauca,from their early senescence onwards, has been analysed qualitatively.On the basis of time of appearance and sporing and durationperiods of fungi, three patterns of colonization have been recognized.The group I members, designated as primary colonists appearon shoots just after their senescence during August. This groupincludes six dematiaceous hyphomycetes and two sphaeropsidales.These are followed by group II members during the late rainyseason, and group III members that appear only for a short periodduring winter. The dominant forms of group II are, 15 dematiaceousand 3 tuberculariaceous hyphomycetes, 2 sphaeropsidales, and1 ascomycete, whereas those representing group III are, 27 dematiaceous,2 moniliaceous and I tuberculariaceous hyphomycetes, 5 sphaeropsidales,1 melanconiales, and 3 mycelia sterilia. These studies also showed that about 94 per cent of the totalmycoflora is constituted by the deuteromycetes of which 12 aresphaeropsidales, 1 melanconiales, 78 moniliales, and 3 myceliasterilia. The moniliales are represented by 3 species of moniliaceae,69 of dematiaceae, and 6 of tuberculariaceae. The phycomycetestage was absent, the three mucorales being discovered onlyby inoculation at an advanced stage of decay. The deuteromycetes,particularly dematiaceous hyphomycetes, have been found to playthe most important role in this phase of decomposition.     

Taxonomy and morphology of dematiaceous fungi isolated from nature

The Hughes system of classification was applied to the identification of dematiaceous fungi isolated from nature. The majority of the isolates encountered could be identified with this system using brightfield microscopy. However, phase contrast microscopy was needed to determine the mode of conidial ontogeny with some species of Phialophora, Exophiala and Wangiella. The identifications based upon phase contrast microscopy were confirmed using the scanning electron microscope (SEM). Scanning electron photomicrographs are presented for Bispora betulina, Cladosporium trichoides, Exophiala jeanselmei, Phialophora revens, P. verrucosa and Wangiella dermatitidis. SEM observations of W. dermatitidis support the present classification of this organism as proposed by other workers. It is suggested that the Hughes system of classification and phase contrast microscopy be used to facilitate identification of isolates of dematiaceous fungi encountered in the clinical laboratory.     

New sources of cytochalasins A and B from dematiaceous hyphomycetes

One hundred isolates of 27 species belonging to 13 genera of dematiaceous hyphomycetes were screened for production of cytochalasins A and B. Most of these isolates (94) were obtained from Assiut University Culture Collection, Botany Department, Faculty of Science, Assiut University, Egypt; three isolates from CBS, The Netherlands; two isolates from DSM, Germany; and one isolate from IMI, UK. The results revealed that 10 isolates of six species representing five genera of fungi produced cytochalasins A and/or B. These species are Alternaria chlamydospora, Cochliobolus spicifer, Diplococcum spicatum, Phoma herbarum, Phoma multipara and Setosphaeria rostrata. This is the first report for the production of cytochalasins A and/or B by these species of dematiaceous hyphomycetes.     

Selective medium for isolation of Fusarium species and dematiaceous hyphomycetes from cereals.

A selective medium containing 2 micrograms of dichloran per ml, 200 micrograms of chloramphenicol per ml, and 1.5% bacteriological peptone was developed for the isolation of Fusarium species and dematiaceous hyphomycetes from cereals. The medium, designated DCPA, was shown to select against species of Aspergillus, Penicillium, Cladosporium, and mucoraceous fungi. DCPA was evaluated for use as an enumeration medium and compared satisfactorily with dichloran-rose bengal-chloramphenicol agar when both media were tested with a range of cereal samples. Fusarium species and dematiaceous hyphomycetes produced well-formed colonies with good conidial production on DCPA, permitting rapid identification of such isolates on this medium.     

Selective medium for isolation of Fusarium species and dematiaceous hyphomycetes from cereals

A selective medium containing 2 micrograms of dichloran per ml, 200 micrograms of chloramphenicol per ml, and 1.5% bacteriological peptone was developed for the isolation of Fusarium species and dematiaceous hyphomycetes from cereals. The medium, designated DCPA, was shown to select against species of Aspergillus, Penicillium, Cladosporium, and mucoraceous fungi. DCPA was evaluated for use as an enumeration medium and compared satisfactorily with dichloran-rose bengal-chloramphenicol agar when both media were tested with a range of cereal samples. Fusarium species and dematiaceous hyphomycetes produced well-formed colonies with good conidial production on DCPA, permitting rapid identification of such isolates on this medium.     

内蒙古大兴安岭地区土壤中的暗色丝孢真菌Ⅱ

从内蒙古大兴安岭地区,根据不同生境,采集混合土样48份。分离获得44个菌株,经鉴定分别隶属于暗色丝孢真菌18属27种,其中包括4个中国新记录种:外来漆斑霉Myrothecium advena、卡氏漆斑霉Myrothecium carmichaelii、橙色葡萄穗霉Stachybotrys aurantia和加拿大短梗蠕孢Trichocladium canadense。除对中国新记录种作了简要描述和绘图外,对23个国内已报道种亦作了分布和生境的引证。所有供研究标本(干制培养物)与活菌种均保存在山东农业大学植物病理学标本室(HSAUP)。     

Ecological study of the fungal populations of the acidic Tinto River in southwestern Spain

The characterization of the microbial ecology of the Tinto River, an extreme habitat with an extremely low pH and a high concentration of heavy metals, revealed an unexpected level of microbial richness. A variety of microbial eukaryotes was isolated, among them several fungal strains that were identified and their physiological characteristics studied. Ninety strains of yeast were isolated from the Tinto River. Fifty-two percent of them were capable of growth in vitro using medium amended with river water. They belong to 6 genera of basidiomycetes (Rhodotorula, Cryptococcus, Tremella, Holtermannia, Leucosporidium, and Mrakia) and 2 of ascomycetes (Candida and Williopsis). In addition, 349 strains of hyphomycetes belonging to 17 genera (most of them ascomycetes) were isolated and studied. Forty-four percent of the isolated filamentous fungi (154 strains) were capable of growing in vitro using medium amended with Tinto River water. Of this percentage, 19% (29 strains) belonged to the genus Penicillium (16 species) and 66% (102 strains) were included in the genera Scytalidium, Bahusakala, Phoma, and Heteroconium or showed dark sterile mycelia, which probably are of dematiaceous hyphomycetes. In addition, we characterized strains of the ascomycete genera Lecythophora and Acremonium and of the zygomycete genus Mortierella, all of them capable of growing in medium amended with river water. Statistical correlation of biological and physicochemical variables suggested a positive relationship between the dematiaceous hyphomycetes and the most extreme physicochemical conditions found in the Tinto River. Principal components analysis confirmed this relationship and also showed that the Acremonium and Lecythophora groups had environmental preferences similar to those of dematiaceous fungi. The spatial positions of the sampling sites were grouped in 2 main clusters: (i) sampling sites in the mine zone in which most of the dematiaceous, Acremonium, and Lecythophora strains were isolated and (ii) sites that were not in the mine zone and sampling station 5 from which were isolated mainly strains of fungi that were not capable of growing in the medium amended with river water and species of the Penicillium genus.     

山西土壤中的暗色丝孢真菌I

从山西省不同地区采集混合土壤样品45份,从中分离获得49个暗色丝孢菌分离物,经鉴定分属于27属中的36种.其中包括1个新种,草原链格孢Alternaria pratensis;1个中国新记录属,锥梗围瓶孢属Chaetopsina;5个中国新记录种:锥梗围瓶孢Chaetopsina fulva、长椭暗双孢Cordana oblongispora、短小腐质霉Humicola brevis、伦德伯格小粘束霉Leptographium lundbergii和亚简黑乌霉Memnoiella subsimplex;其余30个为中国已知种.除对新种进行拉丁文描述和图示外,对中国新记录种也作了简要描述和描绘,对30个国内已报道种则只作分布和生境的引证.所有研究过的标本(干制培养物)与活菌种均保存在山东农业大学植物病理学标本室(HSAUP).     

内蒙古高原土壤中的暗色丝孢菌

从内蒙古高原及河套地区不同生境中,采集混合土样52份。分离获得51个暗色丝孢菌菌株,经鉴定分隶于18属27种。其中包括1个新种,贺兰山小镰孢Fusariella helanshanensis和1个中国新记录种,葫芦细基格孢Ulocladium cucurbitae。除新种具拉丁文特征集要和图示、对中国新记录种作简要描述和绘图外,25个国内已报道种附有分布和生境的引证。所有供研究标本(干制培养物)与活菌种,均保存于山东农业大学植物病理学标本室(HSAUP)。     

青海柴达木盆地土壤中的暗色丝孢真菌Ｉ

从青海省柴达木盆地的不同生态类型地区,采集土样24份,从中分离获得暗色丝孢真菌分离物63个,经鉴定分属于14属中的25种。其中柴达木单格孢Monodictys qaidamensis和多变葡萄穂霉Stachybotrys variabilis为新种,其余为中国已报道种。文中对新种进行了拉丁文描述和图示,对23个国内已知种亦作了分布、生境、产地和海拔高度的引证。所有研究过的标本(干制培养物)与活菌种均保存在山东农业大学植物病理学标本室(HSAUP)。     

青海柴达木盆地土壤中的暗色丝孢真菌Ⅰ

从青海省柴达木盆地的不同生态类型地区,采集土样24份,从中分离获得暗色丝孢真菌分离物63个,经鉴定分属于14属中的25种.其中柴达木单格孢Monodictys qaidamensis和多变葡萄穗霉Stachybotrys variabilis为新种,其余为中国已报道种.文中对新种进行了拉丁文描述和图示,对23个国内己知种亦作了分布、生境、产地和海拔高度的引证.所有研究过的标本(干制培养物)与活菌种均保存在山东农业大学植物病理学标本室(HSAUP).     

Primo contributo alla conoscenza di alcuni ifali demaziacei del Sahara algerino

Abstract

First contribution to the knowledge of some dematiaceous hyphomycetes of algerian Sahara.—Nine dematiaceous hyphomycetes, found in the algerian Sahara, near the Ouarglà Oasis, are here described. Three are reported as new species and two as new records for the desertic provenance.     

Rapid preparation of PCR-amplifiable fungal DNA by benzyl bromide extraction

For isolation of fungal DNA for PCR amplification, we compared three DNA isolation methods: enzymatic cleavage and the use of benzyl chloride or benzyl bromide. Since benzyl bromide is more reactive, its use enabled us to readily isolate the total nucleic acids as a DNA template source from various fungi, including dematiaceous hyphomycetes, for RAPD analysis.     

藏北羌塘草原土壤中的暗色丝孢菌

作为对青藏高原土壤中暗色丝孢菌属、种多样性系统调研的一部分,笔者从采自藏北羌塘草原的20份土样中,分离获得21个暗色丝孢菌分离物,经鉴定分别属于11属中的15种,其中包括1个新种,西藏瓶霉Phialophora tibetensis和2个中国新记录种:蜜色瓶霉Phialophora melinii和暗色帚霉Scopulariopsis fusca,多数种为在此区域首次发现。对新种和中国新记录种进行了描述和图示,对其他12个中国已报道种亦作了分离地点和生境的引证。主模式和等模式标本(干制培养物)分别存放在山东农业大学植物病理学标本室(HSAUP)和中国科学院菌物标本馆(HMAS)。其余研究过的标本(干制培养物)与活菌种保存在HSAUP。     

大兴安岭地区土壤中的暗色丝孢菌Ⅰ

A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium fastidium, Exserohilum pedicellatum, Monodictys asperospora, Papulaspora brachiata, Scolecobasidium anelli, Scolecobasidium verruculosum and Ulocladium tuberculatum are new to China. The other 31 taxa which have been previously reported from China are also listed. Specimens (dried cultures) and living cultures of all fungi studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).     

大兴安岭地区土壤中的暗色丝孢菌Ⅰ

A total of 50 isolates of soil dematiaceous hyphomycetes belonging to 39 species in 18 genera were found from the area of Dahingganling Mountain Range. Among them, Monodictys arxanensis is a new species. Chrysosporium fastidium, Exserohilum pedicellatum, Monodictys asperospora, Papulaspora brachiata, Scolecobasidium anelli, Scolecobasidium verruculosum and Ulocladium tuberculatum are new to China. The other 31 taxa which have been previously reported from China are also listed. Specimens (dried cultures) and living cultures of all fungi studied have been deposited in the Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).     

Desert breath—How fog promotes a novel type of soil biocenosis,forming the coastal Atacama Desert’s living skin

The Atacama Desert is the driest non‐polar desert on Earth, presenting precarious conditions for biological activity. In the arid coastal belt, life is restricted to areas with fog events that cause almost daily wet–dry cycles. In such an area, we discovered a hitherto unknown and unique ground covering biocenosis dominated by lichens, fungi, and algae attached to grit‐sized (~6 mm) quartz and granitoid stones. Comparable biocenosis forming a kind of a layer on top of soil and rock surfaces in general is summarized as cryptogamic ground covers (CGC) in literature. In contrast to known CGC from arid environments to which frequent cyclic wetting events are lethal, in the Atacama Desert every fog event is answered by photosynthetic activity of the soil community and thus considered as the desert's breath. Photosynthesis of the new CGC type is activated by the lowest amount of water known for such a community worldwide thus enabling the unique biocenosis to fulfill a variety of ecosystem services. In a considerable portion of the coastal Atacama Desert, it protects the soil from sporadically occurring splash erosion and contributes to the accumulation of soil carbon and nitrogen as well as soil formation through bio‐weathering. The structure and function of the new CGC type are discussed, and we suggest the name grit–crust. We conclude that this type of CGC can be expected in all non‐polar fog deserts of the world and may resemble the cryptogam communities that shaped ancient Earth. It may thus represent a relevant player in current and ancient biogeochemical cycling.     

黄河源头地区土壤中的暗色丝孢真菌Ⅰ

从黄河源头下游8县区采集的24份土壤样品中分离得到19属34种暗色丝孢真菌,其中长孢齿梗孢Scolecobasidium longisporum和戈壁维罗纳霉Veronaea gobica为两个新种,芦竹节菱孢Arthrinium arundinis为一个新组合名称,并对灰色瓶霉Phialophora cinerescens进行了补充描述。对该地区31个中国已知种亦作了标本引证。所研究真菌的干制培养物及活菌种保存在山东农业大学植物病理学标本室(HSAUP)。     

Amino Acid Analyses of Desert Varnish from the Sonoran and Mojave Deserts

There has long been a debate as to whether desert varnish deposits are microbially mediated or are deposited by inorganic processes. Several researchers have cultured bacteria from the surface of desert varnish suggesting that bacteria are intimately associated with varnish coatings and may play a role in their formation. To test this hypothesis, we have collected scrapings of desert varnish from the Sonoran Desert in Arizona and the Mojave Desert in California and analyzed them for amino acids. Thirteen amino acids were found in desert varnish indicating a biogenic component of these varnishes. Two protein amino acids that were not detected in any of the varnishes are cysteine and tryptophan. Two nonprotein amino acids,β-alanine andγ-amino butyric acid, were found. These are known to be formed by enzymatic decarboxylation, thereby indicating possible organismal activity in varnish. Some D -enantiomers of the amino acids were also found. In addition to small amounts of the D -enantiomer of aspartic acid, which is rapidly formed by racemization and was present in most samples, D -alanine and D -glutamic acid were found. These latter two amino acids are components of the peptidoglycan cell wall material of bacteria. L -lysine was also detected, but not diaminopimelic acid. The combination of L -lysine, D -alanine, and D -glutamic acid is characteristic of the peptidoglycan from Gram-positive bacteria. Although the presence of these biomarkers does not prove that Gram-positive bacteria produce the coatings, finding them is consistent with the hypothesis that they may play a role in desert varnish formation.