Taxonomic and biological characterization and predatory activity of four nematophagous fungi isolates of Arthrobotrys species from Tapachula, Chiapas, Mexico

A batch of nematophagous fungi (NF), isolated from soil and animal faeces at Tapachula, Chiapas, Mexico, was identified through morphological methods and molecular tools. Additionally, the fungi were biologically characterised through their in vitro predatory capability against the free-living nematode Panagrellus redivivus. Molecular identification of nine isolates was achieved by amplifying the 18S, 5.8S and 28S regions using ITS5 and ITS4 oligonucleotides, followed by sequencing and aligning through BLAST. Only species of Arthrobotrys genus: A. oligospora, A. conoides, A. arthrobotryoides and A. musiformis were found. The in vitro bioassay revealed a large variability in the predatory capabilities of the different isolates. The isolate Z1-1-2 of A. arthrobotryoides showed the highest nematode reduction (NR) from 822.8 (+/- 169.5) to only 51.4 (+/- 35.2) = 93.7% NR; in contrast A. oligospora (isolate Z3-2-2) showed the lowest NR from 548.5 (+/- 66.6) to 234.2 (+/- 123.6) = 57.2% Genotyping analysis corroborated the morphological identification. The comparison of sequences with the NCBI sequences showed a close phylogenetic relationship. A phylogenetic tree was generated to compare its phylogenetic relationship with other strains reported in the NCBI. The NF isolated could be potential candidates for future studies on the biological control of nematodes.

Automated summary

A batch of nematophagous fungi isolated from soil and animal faeces in Tapachula, Mexico was identified and characterized for their predatory capability against Panagrellus redivivus. The study revealed the presence of Arthrobotrys species, with different isolates showing varying levels of nematode reduction. Molecular analysis supported the morphological identification and showed a close phylogenetic relationship with other strains.