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Lactic acid bacteria (LAB) have attracted increasing interest recently as cell factories for the production of proteins as well as a carrier of proteins that are of interest for food and therapeutic applications. In this present study, we exploit a lactobacillal food-grade expression system derived from the pSIP expression vectors using the <i>alr</i> (alanine racemase) gene as the selection marker for the expression and cell-surface display of a chitosanase in <i>Lactobacillus plantarum</i> using two truncated forms of a LP × TG anchor. CsnA, a chitosanase from <i>Bacillus subtilis</i> 168 (ATCC23857), was fused to two different truncated forms (short-S and long-L anchors) of an LP × TG anchor derived from Lp_1229, a key-protein for mannose-specific adhesion in <i>L. plantarum</i> WCFS1. The expression and cell-surface display efficiency driven by the food-grade <i>alr</i>-based system were compared with those obtained from the <i>erm-</i>based pSIP system in terms of enzyme activities and their localisation on <i>L. plantarum</i> cells. The localization of the protein on the bacterial cell surface was confirmed by flow cytometry and immunofluorescence microscopy. The highest enzymatic activity of CsnA-displaying cells was obtained from the strain carrying the <i>alr</i>-based expression plasmid with short cell wall anchor S. However, the attachment of chitosanase on <i>L. plantarum</i> cells via the long anchor L was shown to be more stable compared with the short anchor after several repeated reaction cycles. CsnA displayed on <i>L. plantarum</i> cells is catalytically active and can convert chitosan into chito-oligosaccharides, of which chitobiose and chitotriose are the main products.