Chitinolytic microorganisms for biological control of plant pathogens: A Comprehensive review and meta-analysis

Large-scale application of chemical pesticides and insecticides over the years have led to resistance to these chemicals, along with a reduction in crop yield, increase in production cost as well as adverse effects on the environment and human health. In this scenario, there is a need to implement some other techniques to prevent crop losses due to pests and other pathogens. Biological control seems to be a plausible approach to remedy this situation and practice sustainable agriculture through integrated pest management. A feasible way to control nematodes, insects and fungal pathogens can be through the use of chitinase-producing microorganisms. Chitin makes up the exoskeleton of insects, cell wall of fungi, and eggshells of nematodes. Chitinase-producing microorganisms can extensively damage and even kill the pathogens. Therefore, chitinolytic bacteria and fungi might be potential candidates for the biocontrol of numerous plant pathogens. In this review, we aim to discuss the available literature on chitin degrading microorganisms, chitinase enzymes and their importance in biological control. A meta-analysis has been performed with data from the last 2 decades to assess the efficacy of different microbial chitinases on biocontrol of pathogens and a forest plot was produced to conclude the variations among different studies performed so far.