Biocontrol, plant growth-promoting, and bioremediation potential of <i>Aeromonas veronii</i> CMF from the gut of <i>Chrysomya megacephala</i>

Gut system of chitinivorous insect <i>Chrysomya megacephala</i> was purposefully targeted to find unexplored microbial resources based on the rationale of their usual food habits. A phytobeneficial bacterial strain <i>Aeromonas veronii</i> CMF was successfully isolated and characterized up to genomic approaches. The gut isolate <i>A. veronii</i> CMF is a non-pathogenic strain, as proven by the negative results from the hemolysis and DNase tests. Antifungal enzyme production by the CMF exhibited 22.14 ± 2.12, 16.09 ± 0.476, and 1.89 ± 0.46 U/mL chitinase, protease, and β-1,3-glucanase production, respectively. Further, <i>in vitro</i> and <i>in vivo</i> studies also elucidate the effective utilization of such gut bacterial attributes against as many as nine plant pathogenic fungi, demonstrating plant growth-promoting (PGP) and root-colonizing activities with <i>Cicer arietinum</i> and <i>Oryza sativa</i> IR36, as well as heavy metal(loid)s (HMs) resistance, removal, and bioaccumulation potential. Hence, the current study revealed the potential of the gut symbiont CMF to respond against both the biotic and abiotic stresses with PGP attributes for sustainable agriculture.IMPORTANCEGut symbiont <i>A. veronii</i> CMF, with integrated antifungal (chitinase, protease, and β-1,3-glucanase activity), plant growth-promoting (including plant root colonizing potential), and bioremediational attributes can be harnessed as a biotechnological tool for sustainable agriculture and human welfare by fulfilling several sustainable developmental goals. On the basis of such multidimensional gut symbiotic attributes which are validated through genomic-phenotypic observations during this study, it can be suggested that this gut symbiont can perform the host beneficial attributes in the plant rhizosphere, i.e., the "plant gut system" and consequently act as "plant gut symbionts."