Fig. 2

Antifungal activity of L.casei/pPG612.1-BLF in vitro. a C.albicans and L.casei/pPG612.1-BLF were incubated together on a two-layer agar dish at 37 °C for 48 h, C.albicans on the top SDA layer and L.casei/pPG612.1-BLF in the bottom MRS layer. Photos were taken every 12 h. b Twenty microliter of L.casei/pPG612.1-BLF (OD600 = 0.6, 5 × 10⁷–1 × 10⁸ cells/mL) was added into 200 ml of MRS medium with1.5% low melting agarose and mixed gently in the 37 °C water bath. Before cooling down, 20 ml of the mix was poured onto each culture dish (60 mm diameter) and allowed to solidify. Another 10 ml of SDA with 1.5% low melting agarose was poured on to the top of the MRS agar, and then allowed to solidify. Following that, 100 μL of C.albicans liquid containing about 100 cells was placed on the surface of the two-layer agar dish. Two-layer agar dishes containing L.casei/pPG612.1, L.casei and none L.casei were taken as negative controls, one-layer SDA dishes containing C.albicans alone (None MRS) were taken as blank controls. The CFUs of C.albicans incubated with L.casei/pPG612.1-BLF (53.67 ± 1.53CFUs) were fewer than that grown with L.casei/pPG612.1 (86.00 ± 2.64CFUs) and L.casei (87.67 ± 1.53CFUs) (P < 0.01), but there was no difference of CFUs between the latter two groups. Additionally, the CFUs of C.albicans without L.casei (None L.casei, 95.00 ± 3.61CFUs) and without MRS (None MRS, 98.33 ± 3.51 CFU) were more than those with L.casei/pPG612.1 or L.casei. (C) The average size of C.albicans CFUs with L.casei/pPG612.1-BLF (0.57 ± 0.18 mm) was smaller than that with L.casei/pPG612.1 (1.23 ± 0.15 mm) and L.casei (1.18 ± 0.03 mm) (P = 0.02). C.albicans CFUs on two-layer dishes without L.casei (None L.casei, 6.07 ± 0.21 mm) was flatter and bigger than that grown without MRS dishes (None MRS, 4.23 ± 0.10 mm) (P < 0.01)