Thermal Hydrolysis of Wastewater Sludge Followed by Fungal Fermentation for Organic Recovery and Hyphae Fiber Production

Wastewater sludge creates a difficult environmental problem for many large cities.This study developed a three-phase innovative strategy for sludge treatment and reduction,including thermal hydrolysis,fungal fermentation,and anaerobic digestion.Increasing the temperature during the treatment from 140 to 180℃ significantly improved the sludge reduction and organic release efficiencies(p<0.05,one-way analysis of variance(ANOVA)for the triplicate experiments at each temperature).After two cycles of thermal hydrolysis,the overall volatile solid reduction ratios of the sludge were 36.6%,47.7%,and 58.5%for treatment at 140,160,and 180℃,respectively,and the total organic carbon(TOC)conversion efficiency reached 28.0%,38.0%,and 45.1%,respectively.The highest concentrations of carbohydrates and proteins were obtained at 160℃ in sludge liquor,whereas the amount of humic substances significantly increased for the treatment at 180℃(p<0.05,one-way ANOVA for the triplicate experiments at each temperature)due to the Maillard reaction.Fungal fermentation of the hydrolyzed sludge liquor with Aspergillus niger converted the waste organics to valuable fiber materials.The biomass concentration of fungal hyphae reached 1.30 and 1.27 g·L^(-1) in the liquor of sludge treated at 140 and 160C,corresponding to organic conversion ratios of 24.6%and 24.0%,respectively.The fungal hyphae produced from the sludge liquor can be readily used for making papers or similar value-added fibrous products.The paper sheets made of hyphae fibers had a dense structure and strong strength with a tensile strength of 10.75 N·m·g^(-1).Combining fungal fermentation and anaerobic digestion,the overall organic utilization efficiency can exceed 75%for the liquor of sludge treated at 160℃.

Rapid assessment of acid phosphatase activity in the mycorrhizosphere and in arbuscular mycorrhizal fungal hyphae

A pot experiment has been carried out under controlled conditions to study the possibility of applying the technique of in vivo staining for acid phosphatase activity on the roots of mycorrhizal plants and arbuscular mycorrhizal hyphae. The pots had 5 compartments. The central root compartment was separated from the two adjacent hyphal compartments using nylon nets of 30 μm mesh, and the two hyphal compartments were separated from the two outermost compartments with 0.45 μm membranes. Red clover was grown in the root compartment and was either inoculated with the arbuscular mycorrhizal fungus (AMF) Glomus mosseae or uninoculated. Sodium phytate was applied to all compartments. The results show that AMF can increase acid phosphatase activity of clover roots. The plant roots acquired deep red 'mycorrhizal prints'. The external hyphae also had obvious 'hyphal prints' on the test papers, indicating the ability of mycorrhizal hyphae to release acid phosphatase.

Study of Candida Albicans Vaginitis Model in Kunming Mice

The model of vaginal candidiasis in Kunming mice was constructed in order to search for the optima construction conditions and provide an economic animal model of Candida albicans (C. albicans) vaginitis. Estrogen benzoate (E2) was given to mice at different concentrations ranging from 0.0 to 0.05 mg/mouse (4 levels) beginning 72 h prior to vaginal inoculation, then mice were in- oculated intravaginally with various concentrations of stationary-phase C. albicans blastoconidia (ATCC90028) (5 levels) in 20 μL of phosphate-buffered saline (PBS) in each E2 level. General state, scores of genital pathology, the hyphae and vaginal fungal burden (CFU) in vaginal lavage fluid, the hydrops rate of uterus and vaginal tissues for pathological section in mice were observed and ob- tained at day 2, 4, 7, 14 and 21 after inoculation. The results showed the infection rate in mice was related to the dosage of E2 and concentration of C. albicans blastoconidia. Additionally there was better cross-effect between the two treated factors. The infection rate was about 80% on the day 4, and could reach 100% on the day 7 until the end of experiment after inoculated intravaginally in groups of E2I3, E2 0.025 mg/mouse injected hypodermically and inoculated intravaginally with 5×104 C. albicans blastoconidia, and large amount of hyphae and blastoconidia could be observe in superfi- cial layer tissue and canal of vaginal by PAS. From the results in our experiment it was concluded that E2I3 was the optima construction condition in kunming mice.

Arbuscular mycorrhizal symbiosis and ecosystem processes: Prospects for future research in tropical soils

Arbuscular mycorrhizal fungi (AMF) are more widely distributed and can associate with a wide range of plant species. AMF are keystone organisms that form an interface between soils and plant roots. They are also sensitive to environmental changes. AMF are important microbial symbioses for plants under conditions of P-limitation. The AMF are crucial for the functioning of terrestrial ecosystems as they form symbiotic interactions with plants. Mycorrhizal fungi are known to influence plant diversity patterns in a variety of ecosystems globally. AMF hyphae form an extensive network in the soil. The length is a common parameter used to quantifying fungal hyphae. The mycelial network of AM fungi extends into the soil volume and greatly increases the surface area for the uptake of immobile nutrients. Also, AM symbioses improve plants tolerance to drought and enhance plants’ tolerance of or resistance to root pathogens. Also, the networks of AM hyphae play a crucial role in the formation of stable soil aggregates and in the building up of a macroporous structure of soil that allows penetration of water and air and thereby prevents erosion. The functioning of AMF symbiosis is mediated by direct and indirect effects of biotic and abiotic factors of the surrounding rhizosphere, the community, and the ecosystem. AMF have great potential in the restoration of disturbed land and low fertility soil. However, despite the importance of AMF to terrestrial ecosystems, little is known about the effects of environmental changes on AMF abundance, activity and the impact of these changes on the ecosystem services. Therefore, it is important to gain a clearer understanding of the effects of environmental changes on the AM fungal species to guide conservation and restoration efforts.

Arbuscular Mycorrhizal Fungus Mediate Changes in Mycorrhizosphere Soil Aggregates

Many studies have shown that arbuscular mycorrhizal (AM) fungus has an important role in soil aggregate formation and stabilization. While most studies about the effects of AM fungus on soil aggregate have experimental set-ups in single pots or containers with two compartments, these studies cannot differentiate the effects of roots, mycorrhizal roots or hyphae. In this study we used containers with four compartments to split the roots and quantitatively compare the change of soil aggregate in the mycorrhizosphere soil, rhizosphere soil, hyphosphere soil and bulk soil. Our results demonstrate a significant positive correlation among hyphal length density, easily extractable glomalin (EEG) and aggregate mean weight diameter (MWD), geometric mean diameter (GMD) and percentage of soil macroaggregate with a diameter larger than 0.25 mm (R0.25). The GMD and MWD of R0.25 in the hyphal compartment were higher than those in the non-inoculated root compartment, but were lower than those in the mycorrhizal compartment. This suggests the mycorrhizal hyphae had a greater effect than the non-inoculated roots, but less of an effect than the mycorrhizal roots on the formation and stabilization of soil aggregate. The results reveal that plant roots, mycorrhizal roots and mycorrhizal hyphae contribute to aggregate stability in individual ways and that their effects are additive, creating a synergistic stabilizing effect.

Anatomical Studies on Compatibility and Incompatibility of Some Solanaceous Plant Species to Field Dodder (<i>Cuscuta campestris</i>Yuncker)

Four solanaceous plant species, namely hot pepper (Capsicum frutescensL.), potato (Solanum tuberosumL.), tobacco (Nicotiana tabacumL.) and tomato (Lycopersicon esculentumMiller) were anatomically screened for compatibility/incompatibility to field dodder (Cuscuta campestrisYuncker, Cuscutaceae). The development of field dodder haustorium within stem tissues of the studied solanaceous plants was found to depend on the latter’s response to the former’s penetration. In hot pepper and tobacco, which showed a positive response, the haustorium was well developed and its searching hyphae established connections with their vascular tissues. However, potato and tomato showed a negative response and acquired different defense mechanisms against the parasitism of field dodder. In both of them, the field dodder haustorium and/or its searching hyphae exhibited distorted appearance and failed to establish connection with their vascular tissues. Thus, the tested solanaceous plant species could be classified as either compatible (hot pepper and tobacco) or incompatible (potato and tomato) hosts to field dodder.

Glomalin Production and Infectivity of Arbuscular-Mycorrhizal Fungi in Response to Grassland Plant Diversity

Arbuscular-mycorrhizal fungi (AMF) are integral components of most terrestrial ecosystems, with complex interactions between plants and AMF. Our study assessed the impact of plant diversity of native grassland species on AMF infectivity and production of glomalin, an AMF hyphal glycoprotein that may play an important role in soil aggregation. The study was conducted over a 3-year period in field plots planted with 1, 2, 8, or 16 plant species. The mycorrhizal infection potential (MIP) of the plots was assayed in the greenhouse. Glomalin production and MIP were lowest in monocultures and were more closely correlated with plant diversity than with plant cover. Spore density was also greater in higher diversity plots. Lower AMF activity in monoculture plots may contribute to lower productivity and soil quality in plant monocultures. Immunoreactive glomalin levels varied seasonally, with higher levels in late summer than in late spring. Positive correlations were found between glomalin levels and spore density, and between MIP and spore density, but not between MIP and glomalin.

Mycelial Growth of Pleurotus Spp in Se-Enriched Culture Media

Selenium (Se) is an essential element to human. However, this element can be in low content in soil of some regions. Se deficiency may cause Keshan disease, thyroid dysfunction and osteoarthritis. The Se-enriched cereals are an interesting way to prevent these diseases. But, recent studies have shown that Se-enriched mushrooms are a better Se source. This occurs due to the high capacity of the fungi to absorb and transform the inorganic Se to organic forms, which are more bioavailable. Pleurotus ostreatus and Pleurotus eryngii are mushrooms species worldwide consumed and able to Se bioaccumulate. However, depending on the level of this element, it can be toxic for the fungus. Here we showed that the presence of the Se in culture medium decreases fungal growth rate, hyphae diameter and septum distance and causes alteration in color of colony. A garlic strong smell was directly proportional to Se level. P. eryngii was more tolerant to Se than P. ostreatus. So, it is important to screen this element level for Se-enriched mushroom production.

Calcium Signaling during Reproduction and Biotrophic Fungal Interactions in Plants

Many recent studies have indicated that cellular communications during plant reproduction, fungal invasion, and defense involve identical or similar molecular players and mechanisms. Indeed, pollen tube invasion and sperm release shares many common features with infection of plant tissue by fungi and oomycetes, as a tip-growing intruder needs to communicate with the receptive cells to gain access into a cell and tissue. Depending on the comPatibility between cells, interactions may result in defense, inva- sion, growth support, or cell death. Plant cells stimulated by both pollen tubes and fungal hyphae secrete, for example, small cysteine-rich proteins and receptor-like kinases are activated leading to intracellular signaling events such as the production of reactive oxygen species （ROS） and the generation of calcium （Ca^2＋） transients. The ubiquitous and versatile second messenger Ca^2＋ thereafter plays a central and crucial role in modulating numerous downstream signaling processes. In stimulated cells, it elicits both fast and slow cellular responses depending on the shape, frequency, amplitude, and duration of the Ca^2＋ transients. The various Ca^2＋ signatures are transduced into cellular information via a battery of Ca^2＋-binding proteins. In this review, we focus on Ca^2＋ signaling and discuss its occurrence during plant reproduction and interactions of plant cells with biotrophic filamentous microbes. The participation of Ca^2＋ in ROS signaling pathways is also discussed.

Taxonomy of Pseudolagarobasidium(Polyporales,Basidiomycota)

Pseudolagarobasidium(Polyporales,Basidiomycota)is a small,monophyletic genus of crustose,wood-inhabiting fungi with spines and a saprobic,endophytic,or parasitic habit.Seven species are accepted in the genus including two new species,P.belizense from Belize and P.pusillum from Australia.Sequence analysis of the internal transcribed spacer of the ribosomal RNA gene places P.belizense in a monophyletic clade with P.acaciicola and an undescribed foliar endophyte.New combinations proposed include P.modestum for Irpex modestus Berk.,P.pronum for Hydnum pronum Berk.&Broome which is an earlier name for P.calcareum,and P.venustum for Radulodon venustus Hjortstam&Ryvarden.Irpex colliculosum Berk.&Broome from Sri Lanka is conspecific with P.subvinosum.Two species,Sistotrema ochroleucum and Radulum concentricum are not accepted in Pseudolagarobasidium.Pseudolagarobasidium is compared with Radulodon and similar genera.A key to the species of Pseudolagarobasidium is provided.

Artificial Shiro formation of Tricholoma matsutake

One type of soil collected from Maoer-shan in Heilongjiang Province,China was selected to induce hyphal growth of Tricholoma matsutake by a soil screening ex-periment.It was confirmed that hyphal growth of all the tested T.matsutake isolates was significantly stimulated in soil by supplemented with 0.5%~2.0%olive oil.The ag-gregation of hyphae and soil resembled natural Shiro.The biomass of hyphae in the soil increases with increasing olive oil concentrations.Moreover,seedlings of Pinus den-siflora grew well in the soil containing 0.5%~1.0%olive oil and were also successfully infected by T.matsutake isolate A in the soil containing 1.0%olive oil.This study estab-lished a culture system of artificial Shiro formation and also provided a premise for formulation of culture substratum for fruit body formation of T.matsutake.