Control of rice blast disease caused by Magnaporthe oryzae by application of antifungal nanomaterials from Emericella nidulans

Metabolites of Emericella nidulans (EN) were separated by chromatographic methods from crude hexane included emericellin and sterigmatocystin, while crude ethyl acetate found demethylsterigmatocystin. These metabolites proved to be antagonistic to Magnaporthe oryzae, the causal agent of rice blast. Crude extracts and nano-particles derived from EN inhibited M. oryzae. The ethyl acetate crude extract derived inhibited M. oryzae with an effective dose (ED₅₀) of 66 μg/mL. The nanoparticles showed better inhibition of M. oryzae than crude extracts at low concentrations. Nanoparticles, namely from crude ethyl acetate, crude methanol and crude hexane of EN were active against M. oryzae with ED₅₀ of 4.2 μg/mL, 4.5 μg/mL, 8.9 μg/mL, respectively. It detected sakuranetin (rate of flow value is 0.09) in nano-EN treated rice leaves. These nanoparticles inhibited M. oryzae and acted as a new elicitor to induce immunity.

Aflatoxins: Food Safety, Human Health Hazards and Their Prevention

Aflatoxins (AFTs) are group of secondary metabolites produced by filamentous fungi such as Aspergillus flavus, A. parasiticus, A. nomius, and Emericella nidulans. AFTs contaminate foods, feeds, other raw ingredients used to produce them and that pose a significant threat to human health. These toxins designated as aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2), aflatoxin M1 (AFM1) and aflatoxin M2 (AFM2) are hydroxylated metabolites form of AFB1 and AFB2 are known as difuranocoumarin compounds. Naturally, these AFs have carcinogenic, teratogenic and mutagenic effects and caused several metabolic disorders such as aflatoxicosis in domestic animals and humans worldwide. For the increasing in cancer incidences these risk factors are liable. AFB1 is 1000 times more potent hepatocarcinogen found in food then benzo (α) pyrene carcinogen. This chapter offers contamination sources, effects and their controlling approaches to confirm the food safety.

Siderophores of fungi from Lipa clay loam soil, Philippines

This research was conducted to isolate culturable soil-borne fungi from Lipa clay loam soil and identify the types of siderophores they produce. The frequency of fungal isolates was likewise compared across the soil strata. Soil samples were plated on Rose Bengal Agar (RBA) and incubated for five days. Morpho-culturally unique isolates were transferred in Potato Dextrose Agar (PDA) slants and identified using taxonomic keys and by ITS sequencing. Siderophores of each species were then characterized through colorimetric methods. Twenty-nine species of fungi were identified. Six isolates were Basidiomycetes, 1 Zygomycetes and 22 Ascomycetes. Among ascomycetes, two were teleomorphs: Chaetomium globosum Kunze and Emericella nidulans (Eidam) Vuillemin. Isolates were then characterized in terms of their ability to produce siderophores. Majority produced hydroxamate type of siderophores while only Aspergillus tamarii Kita produced all three types of siderophores. Six other species failed to produce any of the three types. Isolates may further be studied for their metal remediating capacity and other biological activities.

In-Vitro and In-Silico Characterization of Xylose Reductase from Emericella nidulans

Background: Lignocellulosic residues generated by various anthropogenic activities can be a potential raw material for many commercial products such as biofuels, organic acids and nutraceuticals including xylitol. Xylitol is a low-calorie nutritive sweetener for diabetic patients. Microbial production of xylitol can be helpful in overcoming the drawbacks of traditional chemical production process and lowring cost of production. Objective: Designing efficient production process needs the characterization of required enzyme/s. Hence current work was focused on in-vitro and in-silico characterization of xylose reductase from Emericella nidulans. Methods: Xylose reductase from one of the hyper-producer isolates, Emericella nidulans Xlt-11 was used for in-vitro characterization. For in-silico characterization, XR sequence (Accession No: Q5BGA7) was used. Results: Xylose reductase from various microorganisms has been studied but the quest for better enzymes, their stability at higher temperature and pH still continues. Xylose reductase from Emericella nidulans Xlt-11 was found NADH dependent and utilizes xylose as its sole substrate for xylitol production. In comparison to whole cells, enzyme exhibited higher enzyme activity at lower cofactor concentration and could tolerate higher substrate concentration. Thermal deactivation profile showed that whole cell catalysts were more stable than enzyme at higher temperature. In-silico analysis of XR sequence from Emericella nidulans (Accession No: Q5BGA7) suggested that the structure was dominated by random coiling. Enzyme sequences have conserved active site with net negative charge and PI value in acidic pH range. Conclusion: Current investigation supported the enzyme’s specific application i.e. bioconversion of xylose to xylitol due to its higher selectivity. In-silico analysis may provide significant structural and physiological information for modifications and improved stability.

Hongos termofilos en nidos de pajaros

Mediante el estudio del material empleado en la construcción de 77 nidos de pájaros silvestres, se aporta información referente .a hongos termófílicos y termotolerantes de Chile.Los resultados se analizaron considerando las siguientes variables: tipo de material empleado por estas aves, especie de pájaro e influencia de las condiciones climáticas, todo esto en relación con algunos aspectos ecológicos. 'En los cultivos de los materiales usados en la construcción de los nidos y subdividido en 4 tipos: (I) Hierbas, hojas, semillas, raicillas; (II) Hierbas, pelos, plumas; (III) Hierba, barro y (IV) Hierba, barro y excrementos: los tipos I, II y III, presentaron la mayor variedad de especies y la mayor cantidad de aislamientos. El número de colonias fúngicas según los períodos estacionales (primavera-verano y otoño-invierno}, no ofreció variaciones significativas.Las especies que experimentaron fluctuaciones, de cierta magnitud fueron: Rhizomucor miehei (Cooney y Emerson) Schipper, Rhizomucor pusillus (Lindt) Schipper, y Malbranchea sulfurea (Miehe) Sigler y Carmichael, que primaron en otoño-invierno.Las especies dominantes en ambos periodos y en orden decreciente fupon: Aspergillus fumigatus Fres., Rhizomucor pusillus (Lindt)Shipper, Thermomyces lanuginosus Tsiklinsky, Rhizomucor miehei (Cooney y Emerson) Schipper, Malbranchea sulfúrea (Miehe) Sigler y Carmichael y Emericella nidulans var. nidulans (Eidam) Vuillemin.La especie más frecuente en todos los nidos fue Aspergillus fumigatus Fres., con una presencia de un 98,7%.Se comenta la posición taxonómica y la .importancia en patología de algunos de los géneros aislados.La especie más significativa a pesar de su escasa presencia, fue Dactylomyces thermophilus Sopp, del cual no poseemos antecedentes que se haya registrado en el hemisferio Sur, ni en Chile.

Biodegradation of Anthracene Compound by Two Species of Filamentous Fungi

Isolation and identification fungi of Emericella nidulans and Aspergillus flavus from a pinkish and yellowish artificial clay, by using potato dextrose agar (PDA). Results revealed that E. nidulans was the best for degrading anthracene (92.3%) with maximum biomass production (3.7gm/l), compared to A. flavus with the rate of degradation (89%) and biomass production of (1.2gm/l), when methylene blue was used as redox indicator after incubating in a shaker incubator 120rpm at 30Co for 8days. Results indicated that E. nidulans has a high ability of anthracene degradation with the rate of (84%), while A. flavus showed the lower level with (77%) by using HPLC.