Microbial consortium in biological control: An explicit example of teamwork below ground

Abstract

Biocontrol strategy has been approved as the most acceptable and sustainable approach to moderate the crop
losses due to phytopathogens and pests. Though the screening of biocontrol agents (BCA) is done meticulously to
select the best among the lot, still a single strain proves inept to fight the numerous opponents present below ground,
around the plant system. Under natural conditions, microbes do live in harmony supporting two to several different
genera together utilizing the available nutrients and thereby creating a team of beneficial cluster acting against their
negative counterparts. This team of helpful microbes acting as a team to protect the plants from the pathogens is
termed as “consortia”. Though there exist certain parameters to be kept in mind before designing an effective
consortium against a particular target pathogen in a definite habitat of the host plant. Microbes tolerant to environmental
shock with longer shelf life and sustainability, possessing higher enzymatic activity with higher rate of metabolism
along with being non-pathogenic to the host plant should be preferred which should incur lower cost of mass
multiplication. Though the mechanisms of action remain the same as that for a single biocontrol agent, but in
consortium the synergism between the microbes is the most essential character that calls for the higher rate of success
in field, comprising different genera of BCA. The present review overviews the studies that have been carried out
reporting the successful effects of applying microbial consortia against different phytopathogens and pests along
with giving a brief account of the mechanisms undertaken by the BCAs to combat the same.