TY - JOUR
T1 - Synthesis and role of melanin for tolerating in vitro rumen digestion in Duddingtonia flagrans, a nematode-trapping fungus
AU - Freitas, Deivid França
AU - Vieira-Da-Motta, Olney
AU - Mathias, Luciana Da Silva
AU - Franco, Roberto Weider De Assis
AU - Gomes, Raphael Dos Santos
AU - Vieira, Ricardo Augusto Mendonça
AU - Rocha, Letícia Oliveira Da
AU - Olivares, Fabio Lopes
AU - Santos, Clóvis De Paula
N1 - Funding Information:
This work was supported by the Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do Rio de Janeiro [grant number E-26/110.040/2013]; The authors would like to thank Mayra Terra Freitas, Tiago Di Moura and Gustavo Lazzaro Rezende for proofreading the manuscript and the referees for their helpful suggestions. This study was funded by the Brazilian fostering agencies Funda??o Carlos Chagas Filho do Rio de Janeiro (FAPERJ) and Funda??o de Coordena??o de Pessoal de N?vel Superior (CAPES). The structural analyses were made possible by the use of the JEOL 1400 PLUS TEM multiuser equipment facility (FAPERJ grant number E-26/110.040/2013). FLO and RAMV are CNPq fellows, and RSG is a FAPERJ/CAPES post-doctoral fellow.
Publisher Copyright:
© 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
PY - 2019/10/2
Y1 - 2019/10/2
N2 - We describe the synthesis and a function of melanin in Duddingtonia flagrans, a nematode-trapping fungus. We tested various culture media treated with L-DOPA, glucose and tricyclazole on fungal growth and melanin distribution using infrared spectroscopy (IS), electron paramagnetic resonance (EPR) and transmission electron microscopy (TEM). In vitro rumen digestion was used to test the environmental stress and then to evaluate the capacity of this fungus to trap nematode larvae. The growth and melanization of the fungus after 21 days of incubation at 30°C were best in Sabouraud dextrose medium. IS indicated the presence of melanin in D. flagrans, with similar bands for commercial melanin used as a control, and assigned the values obtained by EPR (g of 2.0051 ± 0.0001) to the production of melanin by the fungus. TEM indicated that melanin was produced in melanosomes but was not totally inhibited by tricyclazole. Within the limits of experimental error, the predatory activity of fungus treated with tricyclazole was drastically affected after 27 h of in vitro anaerobic stress with rumen inoculum. The deposition of melanin particles on the fungal cell wall contributed to the maintenance of D. flagrans predatory abilities after in vitro anaerobic ruminal stress.
AB - We describe the synthesis and a function of melanin in Duddingtonia flagrans, a nematode-trapping fungus. We tested various culture media treated with L-DOPA, glucose and tricyclazole on fungal growth and melanin distribution using infrared spectroscopy (IS), electron paramagnetic resonance (EPR) and transmission electron microscopy (TEM). In vitro rumen digestion was used to test the environmental stress and then to evaluate the capacity of this fungus to trap nematode larvae. The growth and melanization of the fungus after 21 days of incubation at 30°C were best in Sabouraud dextrose medium. IS indicated the presence of melanin in D. flagrans, with similar bands for commercial melanin used as a control, and assigned the values obtained by EPR (g of 2.0051 ± 0.0001) to the production of melanin by the fungus. TEM indicated that melanin was produced in melanosomes but was not totally inhibited by tricyclazole. Within the limits of experimental error, the predatory activity of fungus treated with tricyclazole was drastically affected after 27 h of in vitro anaerobic stress with rumen inoculum. The deposition of melanin particles on the fungal cell wall contributed to the maintenance of D. flagrans predatory abilities after in vitro anaerobic ruminal stress.
KW - Duddingtonia flagrans
KW - L-DOPA
KW - melanin
KW - nematode-trapping fungi
KW - tricyclazole
UR - http://www.scopus.com/inward/record.url?scp=85067847055&partnerID=8YFLogxK
U2 - 10.1080/21501203.2019.1631896
DO - 10.1080/21501203.2019.1631896
M3 - Journal article
AN - SCOPUS:85067847055
SN - 2150-1203
VL - 10
SP - 229
EP - 242
JO - Mycology
JF - Mycology
IS - 4
ER -