New production process of the antifungal chaetoglobosin A using cornstalks

Chaetoglobosin A is an antibacterial compound produced by Chaetomium globosum, with potential application as a biopesticide and cancer treatment drug. The aim of this study was to evaluate the feasibility of utilizing cornstalks to produce chaetoglobosin A by C. globosum W7 in solid-batch fermentation and to determine an optimal method for purification of the products. The output of chaetoglobosin A from the cornstalks was 0.34 mg/g, and its content in the crude extract was 4.80%. Purification conditions were optimized to increase the content of chaetoglobosin A in the crude extract, including the extract solvent, temperature, and pH value. The optimum process conditions were found to be acetone as the extractant, under room temperature, and at a pH value of 13. Under these conditions, a production process of the antifungal chaetoglobosin A was established, and the content reached 19.17%. Through further verification, cornstalks could replace crops for the production of chaetoglobosin A using this new production process. Moreover, the purified products showed great inhibition against Rhizoctonia solani, with chaetoglobosin A confirmed as the main effective constituent (IC50 = 3.88 µg/mL). Collectively, these results demonstrate the feasibility of using cornstalks to synthesize chaetoglobosin A and that the production process established in this study was effective.(AU)

Endophytic fungus strain 28 isolated from Houttuynia cordata possesses wide-spectrum antifungal activity

The aim of this paper is to identify and investigate an endophytic fungus (strain 28) that was isolated from Houttuynia cordata Thunb, a famous and widely-used Traditional Chinese Medicine. Based on morphological methods and a phylogenetic analysis of ITS sequences, this strain was identified as Chaetomium globosum. An antifungal activity bioassay demonstrated that the crude ethyl acetate (EtOAc) extracts of strain 28 had a wide antifungal spectrum and strong antimicrobial activity, particularly against Exserohilum turcicum (Pass.) Leonard et Suggs, Botrytis cinerea persoon and Botrytis cinerea Pers. ex Fr. Furthermore, the fermentation conditions, extraction method and the heat stability of antifungal substances from strain 28 were also studied. The results showed that optimal antifungal activity can be obtained with the following parameters: using potato dextrose broth (PDB) as the base culture medium, fermentation for 48 d (initial pH: 7.5), followed by extraction with EtOAc. The extract was stable at temperatures up to 80 °C. This is the first report on the isolation of endophytic C. globosum from H. cordata to identify potential alternative biocontrol agents that could provide new opportunities for practical applications involving H. cordata.(AU)

Isolamento de Chaetomium spp. em lesões subcutâneas de um cão: relato de caso / Isolation of Chaetomium spp. on subcutaneous lesions of a dog: case report

Caracterizou-se clinicamente a infecção pelo Chaetomium spp. em um cão, e descreveu-se seu isolamento e identificação. Ao exame dermatológico foram observadas pápulas nas orelhas, no tronco lateral e nos membros pélvicos. Ao rompimento de uma dessas pápulas, fluiu um líquido serosanguinolento com consequente úlcera no local. Foi colhido material para isolamento micológico, por meio de raspado das pápulas da orelha e da cauda. O diagnóstico foi micose subcutânea por Chaetomium spp.(AU)

This work aimed to clinically characterize the infection by Chaetomium spp. in a dog, as well as describe its isolation and identification. Upon dermatological exam, papules on ears, lateral trunk and pelvic members were noticed. After the disruption of these papules there was serosanguineous secretion flowed by consequent ulcer in the region. Material for mycological isolation was picked, and a scraping of papules from ear and tail was done. The diagnosis was subcutaneous mycosis caused by Chaetomium spp.(AU)

Efeito de fungos contaminantes na produtividade de dois isolados de Agaricus blazei em duas formulações de composto / Effect of contaminant on the productivity of two Agaricus blazei isolates in two compost formulations

O efeito dos fungos contaminantes Trichoderma sp. e Chaetomium olivacearum foi avaliado no cultivo dos isolados ABL 99/30 e ABL 04/49 de A. blazei, em duas formulações de composto, à base de palhas de tyfton (Cynodom dactylon) e aveia (Avena sativa). O delineamento experimental foi em esquema fatorial 2 x 2 x 3, inteiramente casualizado, com 6 repetições cada. A unidade experimental constou de 12 ­ 12,5 kg de composto úmido. Nos tratamentos envolvendo o Trichoderma sp. e o C. olivacearum durante a inoculação do A. blazei, foram adicionados 150 g de inóculo de cada um destes fungos contaminantes no momento da inoculação do A. blazei. O experimento foi conduzido em câmara climatizada, com umidade relativa entre 75-90% e temperatura média de 28 ºC. De acordo com os resultados obtidos, verificou-se que as médias de produtividade do isolado ABL 99/30 de A. blazei foram superiores às do isolado ABL 04/49; os fungos contaminantes C. olivacearum e Trichoderma sp. influenciaram negativamente na produção do A. blazei e os diferentes compostos (à base de palha de tyfton e aveia) não influenciaram na produção de basidiomas.

The effect of the contaminant fungi Trichoderma sp. and Chaetomium olivacearum on the cultivation of the ABL 99/30 and ABL 04/49 isolates of A. blazei in two compost formulations made up with tyfton (Cynodom dactylon) and oat (Avena sativa) was evaluated. The experimental design was a totally randomized 2 x 2 x 3 factorial design with 6 repetitions. The experimental unit consisted of 12-12.5 kg of wet compost. During the spawning, 150 g of Trichoderma sp. and C. olivacearum were added to the compost. The experiment was carried out in a climatized room, with humidity between 75-90% and temperature of 28º C. The productivity averages of the ABL 99/30 isolate of A. blazei were higher than those of ABL 04/49 and Trichoderma sp. and C. olivacearum negatively influenced the production of A. blazei. The different composts (based on tyfton and oat straw) did not influence the production of basidiomata.