Microbial detoxification of Colletotrichum falcatum toxin

A study was conducted on the possible detoxification of phytotoxin produced by the sugarcane red-rot pathogen Colletotrichum falcatum Went by antagonistic fungal and bacterial strains. Eleven Pseudomonas fluorescens strains and two Trichoderma harzianum strains were grown on a medium containing the pathogen toxin. Later, the treated toxin was tested for its phytotoxic activity using symptom bioassay, electrolytic leakage and spectral analysis. In symptom bioassay, the phytotoxin incubated with P. fluorescens strains FP 7 and VPT 4 and T. harzianum strain T-5 did not exhibit any symptom on susceptible sugarcane leaves. These treatments caused reduction in electrolyte leakage compared to other treatments and untreated toxin. Also, spectral analysis showed varied spectral patterns by different treatments. The results revealed that certain strains of the biocontrol agents cause detoxification of the pathogen toxin, which is one of the major pathogenicity determinants of the red-rot pathogen.