Lactobacillus rhamnosus

This study examined the modulation of Escherichia coli growth by Lactobacillus rhamnosusinthe presence of polyethylene glycol (PEG), glycero-gelatin, and Theobroma. Growthkineticswere analysed using regression models of colony-forming unit counts over time. In monoculture, E. coli exhibited exponential growth (y = 6.6 + 0.21x, R² = 0.874). Co-culture with L. rhamnosussignificantly suppressed E. coli proliferation (y = 5.97 + 0.02x, R² = 0.324; p < 0.001). Theinclusion of glycero-gelatin moderately stabilized this inhibition (y = 5.93 + 0.03x, R² =0.462; p< 0.001), while PEG produced a synergistic effect, completely halting E. coli growth (y =4.46−0.003x, R² = 0.005; p < 0.001). In contrast, Theobroma reversed inhibition (y = 8.13 +0.17x, R² = 0.679; p = 0.436). These results indicate that physicochemical conditions strongly influenceprobiotic–pathogen interaction, with PEG amplifying inhibition, glycero-gelatin enhancingstability, and Theobroma antagonizing probiotic action against Escherichia coli.

This study evaluated the survival dynamics of Lactobacillus rhamnosus in isolation and in co culture with Escherichia coli underdifferent bases: glycerogelatin, polyethylene glycol (PEG),and Theobroma. In monoculture, L. rhamnosus exhibited steadygrowth (y = 4.27 + 0.24x; R² =0.891), establishing a stable baseline. Co-culture with E. coli in glycerogelatin led to pronounced suppression (y = 5.17 + 0.03x; R² = 0.203; P = 0.002), indicating severe stress and competitive inhibition. PEG similarly reducedviability (y = 5.51 + 0.1x; R² = 0.487; P = 0.015), suggesting limited protective capacity. In contrast, Theobroma mitigated antagonistic effects (y = 6.67 + 0.2x; R² = 0.829; P = 0.032), supporting partial growth recovery. These findings indicate that bases significantly modulate microbial competition, with Theobroma providing the most favorable environment for L. rhamnosus survival amidst E. coli interference