Diversity of facultatively anaerobic microscopic mycelial fungi in soils

The numbers of microscopic fungi isolated from soil samples after anaerobic incubation varied from tens to several hundreds of CFU per one gram of soil; a total of 30 species was found. This group is composed primarily of mitotic fungi of the ascomycete affinity belonging to the orders Hypocreales (Fusarium solani, F. oxysporum, Fusarium sp., Clonostachys grammicospora, C. rosea, Acremonium sp., Gliocladium penicilloides, Trichoderma aureoviride, T. harzianum, T. polysporum, T. viride, T. koningii, Lecanicillum lecanii, and Tolypocladium inflatum) and Eurotiales (Aspergillus terreus, A. niger, and Paecilomyces lilacimus), as well as to the phylum Zygomycota, to the order Mucorales (Actinomucor elegans, Absidia glauca, Mucor circinelloides, M. hiemalis, M. racemosus, Mucor sp., Rhizopus oryzae, Zygorrhynchus moelleri, Z. heterogamus, and Umbelopsis isabellina) and the order Mortierellales (Mortierella sp.). As much as 10–30% of the total amount of fungal mycelium remains viable for a long time (one month) under anaerobic conditions.     

Anaerobic growth ability and alcohol fermentation activity of microscopic fungi

The method proposed in this study was used to isolate fungi grown under anaerobic conditions and to reveal distinctions in their abundance and species composition in different habitats. The ability of micromycetes of different taxa to grow under anaerobic conditions and ensure alcohol fermentation was determined for a representative sample (344 strains belonging to more than 60 species). The group of fungi growing under anaerobic conditions included species with high, moderate, and low fermentation activity. The ability for anaerobic growth and fermentation depended on the taxonomic affiliation of fungi. In some cases, the expression of these characteristics depended on the habitat from which the strain was isolated. The maximum level of ethanol accumulation in culture liquid (1.2–4.7%) was detected for Absidia spinosa, Aspergillus sp. of group flavus, Aspergillus terreus, Acremonium sp., Mucor circinelloides, Mucor sp., Fusarium oxysporum, F. solani, F. sambucinum, Rhizopus arrhizus var. arrhizus, Trichoderma atroviride, and Trichoderma sp.     

Isolation, identification and antifungal susceptibility of lemon pathogenic and non pathogenic fungi

Numerous species of filamentous fungi were isolated from lemon on different plantations in the province of Tucuman, Argentina. The techniques suggested by the Subcommittee of Antifungal Susceptibility of the National Committee for Clinical Laboratory Standards, (USA) were adapted. The effect of three different concentrations of the fungicides imazalil, guazatine, SOPP and thiabendazole on the fungi Fusarium oxysporum, Fusarium moniliforme, Aspergillus niger, Aspergillus flavus, Aspergillus clavatus, Geotrichum candidum, Rhizopus sp, Penicillium sp, Penicillium digitatum and Mucor sp were studied. All the tested strains were resistant to thiabendazole. We assayed a mixture of SOPP (5%), guazatine (350 ppm) and imazalil (100 ppm), which showed a synergic effect on Rhizopus sp. Mucor sp was the only fungus resistant to the four fungicides tested as well as to the above mentioned mixture.     

云南省部分地区产菊粉酶霉菌的初步调查

从昆明,石林,西双版纳,思茅等地区的菊科植物根系上群,昆明,石林地区市售洋姜表土,洋姜提取液中污染菌及洋姜表面霉烂处,分离纯化产菊粉酶菌株,共获得105株霉菌,对以上菌株进行了初步鉴定,对产酶情况进行了初步的研究。发现分属于拟青霉属（Paecilomyces sp.),头孢霉属（Cephalosporium sp.),阜孢霉属（Papularia sp.),丝衣霉属（Byssochlamys sp.),指轮枝孢霉属（Stachylidium sp.)。刚毛菌属（Lacellina sp.)交链孢属（Alternaria sp.),地霉属（Geotrichun sp.)毛霉属（Mucor sp.),枝孢霉属（Claddosporium sp.),金孢霉属（Chrysosporium sp.),镰刀菌属（Fusarium sp.),根霉属（Rhizopus sp．）等13个避的霉菌,是国内未见报道的新的菊粉酶产生菌。     

Glycosphingolipids as a possible signature of microbial communities in activated sludge and the potential contribution of fungi to wastewater treatment under cold conditions

Seven strains of fungi were isolated from activated sludge and identified as Mucor sp., Geotrichum sp., Trichosporon sp., Candida sp., and Trichoderma sp. by 28S rDNA D2 region sequences analysis. The structures of the main ceramide monosaccharides (CMSs) from these fungi were identified as glucosylceramide (GlcCer) consisting of ceramide moieties of 9-methyl-octadeca-sphingadienine (9-Me d18:2), with 2-hydroxyhexadecanoate (h16:0) (Mucor sp. and Geotrichum sp.), 2-hydroxyoctadecanoate (h18:0) (Trichosporon sp. and Candida sp.), and 2-hydroxyoctadecenoate (h18:1) (Trichoderma sp.). Seasonal changes in glycosphingolipids in activated sludge suggest the possibility that microbial flora in activated sludge changes with the seasons, and that fungi adaptable to low temperatures dominate in the cold period, resulting in the maintenance of stable effluent quality. Mucor sp., Geotrichum sp., and Candida sp. satisfactorily reduced the BOD of synthetic sewage at 10 degrees C. These results indicate that fungi in activated sludge can contribute to wastewater treatment in cold conditions.     

几株农用拮抗链霉菌的初步研究

从山西蟒河自然保护区分离到5株链霉菌。琼脂移块法和发酵液扩散法试验表明,它们所产生的抗生素对棉花枯萎病菌(Fusarium oxysporum f.sp.vasinfectum)、棉花黄萎病菌(Verticillium dahliae)、棉花立枯病菌(Rhizoctonia solani)、水稻纹枯病菌(Pellicularia sasakii)、黄瓜枯萎病菌(Fusarium oxysporum f.sp.cucumerinum)等十多种植物病原真菌,对果蔬贮藏期间的病原真菌,如木霉(Trichodermasp.)、意大利青霉(Penicillium italicum)、根霉(Rhizopussp.)等都有明显的抑制作用。     

Fructose production from sucrose and high fructose syrup: A mycelial fungal system

Summary The use of Mucor sp. M105 and Fusarium sp. F5 in the production of fructose from sugarcane sucrose and high fructose syrup (HFS) was investigated. Although Mucor sp. could not utilize sucrose as the sole carbon and energy source for cell growth, Mucor sp. preferentially utilized glucose in a glucose:fructose (1:1) mixture during fermentation to ethanol. In contrast, Fusarium sp. utilized sucrose as sole carbon source by secretion of extracellular hydrolytic enzymes that degraded the disaccharide. In Fusarium sp., glucose formation in the medium was faster than fructose. Due to the low consumption rate of fructose, this substrate remained in the fermentation broth. The application of these biological systems for the production of fructose from either sucrose or HFS is discussed.     

Antimicrobial activity of certain essential oils against hindgut symbionts of the drywood termite Kalotermes flavicollis Fabr. and prevalent fungi on termite-infested wood

Abstract:  When the kalotermitid Kalotermes flavicollis Fabr. pseudergates exposed to Casuarina wood wafers treated separately with different concentrations (5, 15 and 30  μ l/2 g wood wafer) of the essential oils, their spirochaete and flagellate populations abnormally reduced in numbers and vigour. The lophomonadids Joenia sp. and Mesojoenia sp. were the most adversely affected flagellates followed by the polymastigid Foaina sp. and the trichomonadid Tricercomitus sp. The Taxodium distichum essential oil evidently appeared to have the greatest adverse effect on the flagellates (95–100% decline in numbers within 2–4 days) followed by the Eucalyptus citriodora (89–100%) and the Cupressus sempervirens oils (31–100%). While with the hindgut spirochaetes, the adverse effect seemed to be reversed where the E. citriodora essential oil had the greatest effect (54–100%) followed by C. sempervirens (46–100%) and T. distichum (8–100%) oils. Moreover, the essential oils were assayed for their antifungal activity, at 15, 20, 25, 30, and 50  μ l/1 ml acetone/15 ml Czapek-Dox medium, against isolates of four woodrotting fungi associated with Casuarina timber, Aspergillus sp., Penicillium sp., Fusarium sp. and Mucor sp. by a method based on inhibition of the fungus growth on agar plates. E. citriodora exhibited the most potent fungicidal activity against the tested four fungi, followed by T. distichum oil. While the C. sempervirens essential oil appeared to have the least significant antifungal property.     

古银杏内生真菌的分离及其抑菌活性

采用组织分离法从古银杏健康组织中分离得到55株内生真菌, 其中28个分离菌株在PDA培养基上不产孢子, 占总分离菌株的50.9%, 其它菌株根据其在PDA培养基上的培养特征, 10株被鉴定为青霉、6株为曲霉、4株为交链孢霉、3株为简梗孢霉, 另外酵母、毛霉、小单头孢霉、镰孢霉各1株。考察内生真菌培养上清对7种受试指示菌的抑制作用, 共筛选得到23株至少对一种指示菌的生长有抑制作用的菌株, 其中11株为不产孢真菌, 占活性菌株的47.83%。对活性最强的一株菌进行形态学和分子生物学鉴定, 将其确定为Xyla     

Selective effects of three herbicides on the fungus flora of egyptian soil

2,4-D (2,4-dichlorophenoxyacetio acid) when applied to the soil at three doses (1.9, 7.6 and 15.2 mg per kg dry soil) had a stimulating effect on the total count of soil fungi and on several fungal species especially between 5 and 20 d after treatment. When the herbicide was incorporated in the agar medium it had a stimulating effect on the counts of total fungi, Aspergillus sp., A. niger, A.fumigatus and Fusarium app. at the low dose (6.3 ppm), but wag toxic at this dose toward Humicola grisea and Myrothecium verrucaria at the medium and high doses (25.2 and 50.4 ppm), it was toxic to the total count of fungi and to the majority of fungal species. VCS-438 [2-(3,4-dichlorophenyl)-4-methyl-l,2,4-oxadiazolidine-3,5-dione] was beneficial to the total count of fungi 2 and 5 d after soil treatment with the medium dose (8.0 mg per kg dry soil). Some fungal species could benefit from the low and the high doses (2.0 and 16.0 mg per kg dry soil) after these experimental periods. In the agar medium the counts of total fungi, Aspergillus sp., A. niger and A.fumigatus were almost significantly reduced by the three doses (6.8, 27.2 and 54.8 ppm). Planavin (4-methylsulphonyl-2,6-dinitro-N,N-dipropylaniline) was stimulating for the total count of fungi, Aspergillus, A.niger and A.ochraceus 2 and 5 d after treatment with the medium dose (8.0 mg per kg dry soil), and was also stimulating to Fusarium population at the medium dose after 2 d and at the high dose (16 mg per kg dry soil) after 20 d. In the agar medium Planavin at the low dose (6.8 ppm) was stimulating to A.terreus and inhibitory to A.nidulans and A.fumigatus. The medium and high doses (27.2 and 54.8 ppm) were generally toxic to the total count of fungi.     

Degradation of polycyclic aromatic hydrocarbons (2–7 rings) under microaerobic and very-low-oxygen conditions by soil fungi

Soil fungi were studied regarding their ability to degrade polycyclic aromatic hydrocarbons (PAHs) and produce ligninolytic enzymes under microaerobic and very-low-oxygen conditions. Several PAHs were used as substrates for soil fungi under microaerobic and very-low-oxygen conditions. Activities of lignin-peroxidase, manganese-peroxidase, and laccase were monitored over a 30-day period. PAH degradations were analyzed using C₁₈ reversed-phase HPLC. Low-molecular-weight PAHs (LMW-PAHs, 2–3 rings) were degraded most extensively by Aspergillus sp., Trichocladium canadense, and Fusarium oxysporum. When growing on high-molecular-weight PAHs (HMW-PAHS, 4–7 rings), the highest degradations were reached by T. canadense, Aspergillus sp., Verticillium sp., and Achremonium sp. In this study, these fungi revealed a great capability to degrade a broad range of PAHs under low-oxygen conditions. In addition, lignolytic enzyme activities were observed during fungal growth on these compounds. These results suggest fungi have the ability to bioremediate PAH-contaminated soils and that they use these compounds as carbon sources for growth.     

Antifungal and antibacterial activities of Araucaria araucana (Mol.) K. Koch heartwood lignans

Five lignans (secoisolariciresinol, pinoresinol, eudesmin, lariciresinol, and lariciresinol-4-methyl ether) were isolated from an MeOH extract from Araucaria araucana (Mol.) K. Koch wood for the first time in this species and their structures determined with spectroscopic methods. The antimicrobial activities of these compounds were determined for the bacteria Citrobacter sp., Bacillus subtilis, Escherichia coli, Micrococcus luteus, Staphylococcus aureus, and Pseudomonas aeruginosa, and for the white rooting and staining fungi Mucor miehei, Paecilomyces variotii, Ceratocystis pilifera, Trametes versicolor, and Penicillium notatum, and in addition, the MeOH extract was evaluated against Aspergillus niger, Candida albicans, Fusarium moniliforme, F. sporotrichum and Trichophyton mentagrophytes. The most sensitive bacteria against pinoresinol were the Gram-positive. However, secoisolariciresinol exhibited a significant antifungal activity on fungi of white rooting and wood staining and this compound completely inhibited the mycelial growth of T. versicolor and C. pilifera at 300 and 400 microg per disc, respectively, whereas pinoresinol showed a moderate inhibitory activity. On the other hand, the MeOH extract had the highest activity against rooting and staining and pathogenic fungi as well as T. versicolor, Fusarium spp. and Trichophyton mentagrophytes, inhibiting completely the growth at 400 microg per disc.     

5种优势腐生真菌降解华山松针叶的酶活测定

【目的】分析腐生真菌降解华山松落针过程中各种酶活性变化与酶间关系,探索真菌对华山松落针的降解能力。【方法】通过形态学观察和转录间隔区ITS序列分析,鉴定分离自华山松凋落物的5种优势菌株。以此为供试菌株,华山松落针为底物,通过发酵纯培养方法,测定底物总有机物质(Total organic matter,TOM)质量损失率及在发酵过程中产生的内切葡聚糖酶(Endoglucanase,EG)、木聚糖酶(Xylanase,Xyl)、木质素过氧化物酶(Lignin peroxidase,Li P)、锰过氧化物酶(Manganese peroxidase,Mn P)和酸性磷酸酶(Acid phosphatase,AP)活性。【结果】5种菌株分别为Mucor sp.、Pestalotiopsis sp.、Allantophomopsis sp.、Phoma sp.和Hypocrea sp.。5种菌引起的针叶TOM质量损失率在6.63%-15.77%之间,Pestalotiopsis sp.具有最高的AP酶活性,且EG酶、Xyl酶和Li P酶3种酶活性较高。Allantophomopsis sp.的Li P酶活性最高,并具有很高的Mn P酶活。Hypocrea sp.分泌的EG酶、Xyl酶活性低,但能产生Li P酶且有较高的AP酶活。相关性分析表明菌株分泌的AP酶活性与TOM质量损失率负相关,EG酶、Xyl酶及AP酶3种酶之间存在协同作用,特别是EG与AP之间。【结论】5种腐生真菌对华山松针叶均有降解作用,降解能力:Pestalotiopsis sp.>Allantophomopsis sp.>Hypocrea sp.>Phoma sp.>Mucor sp.。酶活大小及酶协同作用共同影响针叶降解,Pestalotiopsis sp.、Allantophomopsis sp.和Hypocrea sp.能产生木质纤维素降解酶并能引起较高的质量损失率,因此这3株菌为木质纤维素降解真菌。     

Filamentous fungi preservation in distilled water.

Some methods for keeping the fungal Culture Collection have been used. However, the choice of either one on the basis that must ensure the cultural genetic stability and its phenotipic characteristics. In this work the preservation method in distilled water recognized in the literature as a single, economic and certain method that guarantie the survival of fungus cultures for long periods was used. 26 strains of generus and species: Aspergillus niger, Aspergillus candidus, Fusarium sp., Fusarium moniliforme, Mucor griseocyanum, Syncephalastrum sp., Trichoderma sp., Trichoderma harzianum and Trichoderma koningii were preserved. Enough inoculum from well developed cultures (mainly spores and hyphae) poured in flasks with sterile distilled water warranted a 100% of survival of those microorganisms for two years. At the same time no apparent changes were observed in respect to morphology and macroscopic features.     

食真菌线虫与真菌的相互作用及其对土壤氮素矿化的影响

采用悉生培养微缩体系,探讨了食真菌线虫(燕麦真滑刃线虫)与两种真菌(真菌Ⅰ：外皮毛霉和真菌Ⅱ：丛梗孢科的一种)间的相互作用及其对土壤氮素矿化的影响．结果表明,燕麦真滑刃线虫在取食两种真菌时表现为在真菌Ⅱ上的生长优于真菌Ⅰ,两个处理的线虫数达到显著差异．食真菌线虫对真菌的取食活动促进了真菌的增殖：接种真菌Ⅱ加线虫处理中真菌Ⅱ的数量是仅接种真菌Ⅱ处理的2．5～3．5倍,增幅在整个培养期基本稳定;而接种真菌Ⅰ加线虫处理中真菌Ⅰ的数量在培养前期(10d)是仅接种真菌Ⅰ处理的1．1～2．0倍。之后增幅达5．0～5．7倍．线虫和真菌的生长及增殖基本保持同步．食真菌线虫与真菌的相互作用显著提高了土壤铵态氮和矿质态氮含量,促进了土壤氮的矿化,其中线虫与真菌Ⅰ的相互作用对提高矿质态氮含量的贡献显著大于线虫与真菌Ⅱ的相互作用。     

Diversity in antifungal activity of strains of <Emphasis Type="Italic">Chromobacterium violaceum</Emphasis> from the Brazilian Amazon

Chromobacterium violaceum is a free-living Gram-negative bacterium found in soil and aquatic habitats; abundantly present in the Brazilian Amazon, it is an important example of exploitable microbial diversity of the tropics. In this study, 24 strains from the Brazilian Amazon and ATCC 12472(T) were investigated for biocontrol potential of seven fungi pathogenic to soybean [Glycine max (L.) Merril] seed. Both cells and the supernatants of two Brazilian strains, 07-1 and 27-1, together with ATCC 12472(T) were strongly antagonistic to six out of the seven fungi. The antifungal activity of the Brazilian strains to Fusarium sp., Phomopsis sp. and Cercospora kikuchi was consistently stronger than that of ATCC 12472(T). In addition, the two Brazilian strains, but not ATCC 12472(T), were effective against Corynespora sp., and all three strains and their supernatants were equally effective against Aspergillus sp. and Colletotrichum sp. None of the strains had antifungal activity against Botroyodiplodia sp. Three potential mechanisms related to the antibiosis were investigated: violacein toxicity, cyanide production and chitinolytic activity; however, it was not possible to associate any of them with the antifungal activity. The results highlight the biotechnological potential still to be explored within the poorly characterized microbial biodiversity of the tropics.     

Armillaria mellea as a cause of oak decline in Hatam-baigh forest of Iran

A200 ha forest of "Hatam-baig" is located in Ardebil Province on the Northwest of Iran. Oak trees (Quercus macranthera Fisch & Mey) in this forest have been faced with declining and extinction since 1991, that has destructed about one third of the forest trees until now. This disorder was expressed in various symptoms including wilting, defoliation and decline. In order to identify factors causing decline, a study was managed from 1998 to 2001. Samples were taken from roots, trunks, crowns and soil beneath the canopy and were cultured on different culture media subsequently. Armillaria mellea (Vahl) P. Kumm., Phytophthora cryptogea Pethybr. & Laff., Dematophora sp., Pythium aphanidermatum (Edson) Fitzp. and Fusarium spp. were the most common isolated fungi. A. mellea appeared to be the essential causal agent of the decline according to the studies made on oak tress decline around the world and based on brown rot observed beneath mycelial fans in the cross section prepared from the trunk and characteristics of the isolated fungi. The fungus activity had been favored by physiological weakness and stresses in oak rootstocks caused by brown- tail moth (Euproctis chrysorhoea L.) and drought stress in infected trees. The biological species of this fungus was identified as Armillaria mellea, using hybridization tests and application of haploid test strains. The fungi such as Phytophthora sp., Pythium sp., and Dematophora sp. can not be infective in this forest due to being hydrophylous. In the southern part of the forest with remarked steepness, the severity of the decline appears to be more than that in the smoothly northern part. The decline of Q. macranthera is reported as matrix nova. The report of the isolated fungi from this oak species is also universally new.     

几种药用植物内生真菌抗真菌活性的初步研究

从三尖杉,南方红豆杉及香榧中分离出172株内生真菌,对其进行抗菌活性检测,结果表明共90株内生真菌对一种或多种植物病原真菌,如红色面孢霉（Neurospora sp.）,木霉(Trichoderma sp.）,镰刀菌（Fusarium sp.）等有抑制作用,来自三尖杉、南方红豆杉和香榧的抗菌活性菌株比例分别为40％,54.2%及57.1%。其中平板抑菌圈直径大于15mm的高抗菌株有35株。按Ainsworth等鉴定系统和方法进行鉴定,具有抗菌活性的内生真菌主要分布于心青霉属、镰孢菌属等18个属中。     

In vitro suppression of fungi caused by combinations of apparently non-antagonistic soil bacteria

We hypothesized that apparently non-antagonistic soil bacteria may contribute to suppression of fungi during competitive interactions with other bacteria. Four soil bacteria (Brevundimonas sp., Luteibacter sp., Pedobacter sp. and Pseudomonas sp.) that exhibited little or no visible antifungal activity on different agar media were prescribed. Single and mixed strains of these species were tested for antagonism on a nutrient-poor agar medium against the plant pathogenic fungi Fusarium culmorum and Rhizoctonia solani and the saprotrophic fungus Trichoderma harzianum. Single bacterial strains caused little to moderate growth reduction of fungi (quantified as ergosterol), most probably due to nutrient withdrawal from the media. Growth reduction of fungi by the bacterial mixture was much stronger than that by the single strains. This appeared to be mostly due to competitive interactions between the Pseudomonas and Pedobacter strains. We argue that cohabitation of these strains triggered antibiotic production via interspecific interactions and that the growth reduction of fungi was a side-effect caused by the sensitivity of the fungi to bacterial secondary metabolites. Induction of gliding behavior in the Pedobacter strain by other strains was also observed. Our results indicate that apparently non-antagonistic soil bacteria may be important contributors to soil suppressiveness and fungistasis when in a community context.     

Mycobiota associated with larval mines of Thrypticus truncatus and T. sagittatus (Diptera, Dolichopodidae) on waterhyacinth, Eichhornia crassipes, in Argentina

Thrypticus truncatus is a candidate agent for biocontrol of waterhyacinth; the larvae of this diptera mine in the petioles and feed on the phloem in the vascular bundles. The mycobiota associated with T. truncatus and T. sagittatus mines was investigated during two surveys undertaken in the spring and autumn in the Delta of the Paraná River, Argentina. Isolations were made from the mines and larval feeding points, as well as from the larvae, following dissection of the petioles, and plated onto agar. Young and upper parts of the petioles without Thrypticus mines were used as controls. Twenty eight fungal species were isolated from the mines. Pestalotiopsis guepinii, Mucor attenuatus, Phoma tropica, Achlya americana, Fusarium avenaceum, Cladosporium cladosporioides, Clonostachys rosea, Epicoccum purpurascens, Plectosporium tabacinum, Alternaria alternata, and Acremonium sp. were the most common fungi associated with mines and feeding points. Cladosporium cladosporioides, Cytospora sp., Mucor attenuatus, and Phoma tropica were associated with the larval body. The list of fungi in mines was compared with bibliographic information to determine if the species are known pathogens on waterhyacinth or other plant species. This is the first study on mycobiota associated with T. truncatus and T. sagittatus mines in waterhyacinth petioles in Argentina.