Antagonistic potential of a psychrotrophic fungus: Trichoderma velutinum ACR-P1

Trichoderma is a well explored genus for plethora of bioactivities due to their cosmopolitan existence, diverse metabolomics, reproductive and competitive efficacies. Mycoparasitism and antibiotics production seems to be the probable mechanisms underlying their use as biocontrol agents. The aim of this study is to investigate the antagonistic potential of a new psychrotrophic fungus Trichoderma velutinum ACR-P1 as a promising biocontrol agent against destructive phytopathogens with probable underlying mechanisms. Antagonistic potential of T. velutinum ACR-P1 against the important phytopathogens, that is, Fusarium oxysporum, Verticillium dahliae, Alternaria alternata and Colletotrichum capsici was demonstrated by the in vitro dual culturing experiments. Also, probable mechanism underlying antagonism was studied by investigating enzymatic cell wall hydrolytic potential of the strain and potential for production of secondary metabolites i.e. non-ribosomal peptides (NRPs). The putative strain ACR-P1 showed immense potential of inhibiting the growth of all the four test phytopathogens and its capability of producing cell wall degrading enzymes (CWDE) i.e. chitinase, cellulase and protease utilizing colloidal chitin, carboxymethyl cellulose and milk protein respectively as sole source of carbon and energy as illustrated by growth and agar well diffusion assays. Also, metabolic profiling firstly revealed the production of two groups of the NRPs by T. velutinum ACR-P1 as reported in our earlier study on the strain (Sharma et al., 2016). Mycoparasitism supported by NRPs and CWDEs substantiate their use as biocontrol agents. The psychrotrophic strain is endowed with immense potential to be included as a new candidate in the list of biocontrol agents (BCA). The potential antagonism against the important destructive phytopathogens signifies T. velutinum ACR-P1 as a BCA and can be exploited in fields to get rid of devastating impacts of these phytopathogens on the crops.