*2.2.2 Lytic enzymes of the cell wall*

Some PGPR produce enzymes that are involved in the lysis of cell walls and neutralization of pathogens by interrupting a particular stage of development or the cell cycle [79], playing an important role in promoting plant growth by protecting them of biotic and abiotic stresses due to the suppression of these pathogens. Among the produced enzymes for this purpose are chitinases, dehydrogenases, β-glucanases, lipases, phosphatases, or proteases [59]. The cell wall of most fungi is formed by residues of β-1,4-N-acetyl-glucoseamine and chitin, so that the bacteria that produce β-1,3-glucanase and chitinase can control the growth of phytopathogen [43]. Furthermore, some PGPR are able to produce this kind of enzymes and protect the crops under abiotic stress like *Bacillus licheniformis* A2 that produces


#### **Table 4.**

*PGPR that produce antibiotics and their effects as biocontrol agents.*

chitinase and protects *A. hypogea* against *Fusarium oxysporum* f. sp. *cubense* under salinity conditions [84]. **Table 5** shows some examples of bacteria capable of producing these types of degrading enzymes.
