This study was aimed to design a novel edible coating based on Shirazi balangu seed mucilage (SBM) containing cell-free supernatant (CFS) of Levilactobacillus brevis G145 to improve the quality and shelf-life of lamb meat slices during cold storage. The CFS (1 and 2 %) was added to the SBM, and the obtained edible coating was used to coat the meat slices. The samples were stored at 4 °C for 1, 4, 7, and 10 days. In comparison to the control sample, the meat slices coated with SBM+2 %CFS had manifestly lower total viable count (6.62 vs. 13.10 log CFU/g), psychrotrophic count (3.47 vs. 8.80 log CFU/g), Escherichia coli count (0.80 vs. 1.54 log CFU/g), Staphylococcus aureus count (0.81 vs. 1.57 log CFU/g), fungi count (0.68 vs. 2.38 log CFU/g), pH (5.70 vs. 6.51), and peroxide value (4.89 vs. 10.80 meq O2/kg), and higher moisture content (70 vs. 60 %), hardness (67.80 vs. 57.60 N), and sensory properties by the end of storage period. The results of this study revealed that the SBM+CFS- based edible coating increased the shelf-life of lamb meat efficiently.