Mycotoxin degradation by microbial metabolites

Extracellular metabolites of Gliocladium roseum GRZ7 are able to destroy aflatoxin B1 and zearalenone (by 61.9 and 68%, respectively). The determined optimum pH and temperature confirm the enzymatic nature of these metabolites.

“MYCO SYNTHESIS OF SILVER NANOPARTICLES USING GLIOCLADIUM ROSEUM (CLONOSTACHYS ROSEA (LINK) SCHROERS, SAMUELS) AND ITS ANTIMICROBIAL EFFICACY AGAINST SELECTED PATHOGENS”

Objective: Antimicrobial efficacy of silver nanoparticles from Gliocladium roseum, culture filtrate (C. F.) and mycelial mat extract (M. E.) against selected pathogens. Methods: Culture filtrate (C. F.) and Mycelial mat extract (M. E.) of Gliocladium roseum were subjected to 10 Mm silver nitrate solution for the synthesis of silver nanoparticles. Formed silver nanoparticles were evaluated via UV-vis spectroscopy and the structural elucidation was done by FT-IR and TEM. Antimicrobial efficacy was tested against bacterial (Salmonella typhi and Klebsiella pneumonia) and fungal (Cladosporium cladosporioides and Alternaria alternata) pathogens. Different nanoparticle concentrations-50, 100, 150 and 200 µl were checked via disc diffusion method. Results: Gliocladium roseum (C. F. and M. E.) on interaction with silver nitrate solution effectively reduced metallic silver exhibiting a colour change from yellow to dark brown within 24 h due to the formation of silver nanoparticles. The UV-vis spectrum of C. F. and M. E. showed maximum absorption peaks at 350-400 nm and 400-450 nm respectively and FT-IR and TEM showed strong N-H bonding and spherical shaped silver nanoparticles with the size of 11-19 nm (C. F.) and 25-38 nm (M. E.). Antimicrobial analysis resulted in efficient inhibitory activity against Salmonella typhi, Klebsiella pneumonia and also showed moderate inhibitory activity against Alternaria alternata and Cladosporium cladopsorioides. Conclusion: The synthesis of silver nanoparticles from fungus Gliocladium roseum is simple, cheap, safe and eco-friendly thus emphasising on large scale scientific application.

Impact of Coherent Laser Irradiation on Germination and Mycoflora of Soybean Seeds—Innovative and Prospective Seed Quality Management

Laser irradiation is considered a new technology in agriculture; however, the success of irradiation depends on the selection of precise parameters for the light source and exposure. In this study, the impact of laser stimulation on germination and the occurrence of mycoflora in soybean seeds was assessed. The following factors were considered: (1) irradiation using blue and red coherent lights, (2) irradiation of seeds only (a), use of Bradyrhzobium japonicum vaccine only (b), and irradiation of the seeds plus the Bradyrhzobium japonicum vaccine (c). The germination index, seedling weight and seeds infected by fungus were determined. It was found that the laser treatment of seeds increased germination and seedling weight. Laser irradiation affected the abundance of species Phoma glomerata, Botrytis cinerea, Rhizopus nigricans and Gliocladium roseum. The use of blue laser (LB—514 nm) reduced the number of the non-pathogenic species, R. nigricans and G. roseum.

Extracellular enzymatic activities of 32 fungal species

Se investigó en 32 especies fúngicas, la producción de enzimas extracelulares y ms determinaciones cualitativas (amilasa, celulosa, caseinasa, fosfatasa, lipasa, pectinasa y ureasa). La detección de los enzimas en los cultivos fúngicos en agar varió ampliamente.En la mayoría de los cultivos fúngicos se detectaron: amilasas, ureasas, y fosfatasas. Las celulosas se pesquizaron particularmente en cultivo de Aspergillus flavus, A. fumigatus, Cladosporium cladosporioides Penicillium brevicompactum, Rhizopus stolonifer, Scopulariopsis flava y Trichothecium roseum. Penicillium digitatum y P.duclauxi fueron productores de caseinasa en un alto grado. La actividad lipolítica se detectó en cultivos con grasas sintéticas tweens 20, 40, 60, y 80 como sustrato para lipasa. Indicaron actividad lipolítico para estos sustratos A. flavus, Aureobasidium pullulans, C. cladosporioides, Gliocladium roseum, Mycothypha microspora, Microsporum gypseum, P. brevicompactum y Scopulariopsis brumptii. Productores de pectinasas fueron las cepas de A. flavus, C. cladosporioides y Fusarium oxysporum, P. brevicompoctum y Ulocladium atrum

Biocatalysis of ursolic acid by the fungus Gliocladium roseum CGMCC 3.3657 and resulting anti-HCV activity

Biocatalysis of ursolic acid (UA 1) by Gliocladium roseum CGMCC 3.3657 was investigated.

Evaluación in vitro de diez cepas de hongos nematófagos para el control de Meloidogyne exigua, Meloidogyne incognita y Radopholus similis

<p class="p1">El desarrollo de alternativas al uso de nematicidas, plaguicidas altamente tóxicos, es un tema de importancia en la actualidad. En esta línea ha habido un creciente reconocimiento de la efectividad del control biológico por medio de hongos nematófagos. Por tales razones, y con el fin de determinar la capacidad nematófaga de hongos que habían sido previamente aislados de fincas en la Región Huetar Norte, se establecieron ensayos <em>in vitro,</em> en los que se evaluó la mortalidad de individuos de <em>Radopholus similis</em>, <em>Meloidogyne incognita</em> y <em>M. exigua</em> expuestos a estos hongos. Según los criterios establecidos, las cepas de <em>Hypocrea virens</em> y <em>Penicillium janthinellum</em> no presentaron actividad nematicida contra ninguna de las especies de nematodos. <em>Monacrosporium megalosporum</em>, <em>Trichoderma spirale</em> y <em>T. asperellum</em> 2 presentaron actividad nematicida contra <em>R. similis</em> y <em>M. exigua.</em> Mientras que <em>Gliocladium roseum</em> y <em>Fusarium oxysporum</em> mostraron actividad únicamente en contra de <em>R. similis</em>. <em>T. asperellum</em> y <em>Gongronella butleri</em> también mostraron potencial de control en contra de <em>M. exigua</em>. Ninguna de las cepas cumple con lo establecido para considerarla con actividad nematicida contra juveniles de <em>M. incognita. </em>Además<em>, P. lilacinus</em> y <em>F. oxysporum</em> mostraron capacidad para parasitar huevos de las dos especies de <em>Meloidogyne </em>evaluadas. <em>T. asperellum</em> y <em>T. spirale </em>parasitaron huevos de <em>M. incognita,</em> mientras que <em>M. megalosporum</em> parasitó un 56% de los huevos de <em>M. exigua. </em>Estos resultados deben ser confirmados con pruebas en campo, estudiar posibles metabolitos producidos por estos hongos, evaluar la posibilidad de mejoramiento genético de los mismos y estudiar los genes involucrados en su capacidad para parasitar nematodos.</p>

Colletotrichum orbiculare on watermelon: Identification and in vitro inhibition by antagonistic fungi

Anthracnose caused by the fungus Colletotrichum orbiculare is one of the most significant diseases of Cucurbitaceae. In Serbia watermelon fruits with typical anthracnose lesions were collected during the year of 2015. Affected fruits showed sunken, dark brown to black lesions with orange conidial masses produced in black acervuli. In an attempt to identify the causal organism, small pieces of necrotic tissue were surface sterilized and placed on potato dextrose agar (PDA). Macroscopic and microscopic morphologicaly characteristics of three isolates were observed after growth on PDA for 7 days at 25 ?C under a 12 h light/dark cycle. Fungal colonies developed white, grey to black dense aerial mycelium. Conidia were hyaline, aseptate, straight and cylindrical to clavate, 9-12.5 ?m ? 4-5.5 ?m. Fungal isolates were also characterized by sequencing of the internal transcribed spacer (ITS) rDNA region using ITS1F/ITS4 primers and ?-tubuline 2 gene using T1/Bt2b primers. The nucleotide sequences were deposited in GenBank (ITS Acc. No. KT454386, KT454387 and KT454388; ?-tubuline 2 gene Acc. No. KT581236, KT581237 and KT581238). BLAST analysis of ITS and ?-tubuline 2 gene sequences showed that our isolates were 100% identical to other C. orbiculare in NCBI GenBank. Pathogenicity test was conducted on symptomless, detached watermelon fruits. All tested isolates caused anthracnose lesions on watermelon fruits after 10 days of incubation. Trichoderma harzianum (DSM 63059) and Gliocladium roseum (DSM 62726) were evaluated in vitro for their antagonistic potential against C. orbiculare. The results of this study identify T. harzianum and G. roseum as promising biological control agents (BCAs) for further testing against anthracnose disease on water?melon fruits.