Objective: To characterize the interaction of Lactobacillus plantaruni 337D UKM B-2627 strain, which has probiotic properties, with kaolinite and montmorillonite.
Methods: The methods of infrared spectroscopy, transmission electron microscopy, the adsorption-structural static volumetric method, microbiological and statistical methods were used.
Results: The characteristics of the porous space of clay mineral particles were practically did not change compared with initial samples during the interaction with L. plantarum 337D UKM B-2627 strain cells, pore size distribution had become wider due to the emergence of large diameter pores, reduced surface area, but the adsorption capacity and the layered structure of clay minerals preserved. For the first time the ef- fect of kaolinite and montmorillonite on growth of L. plantaruni 337D strain in vitro was studied. The greatest stimulating effect of clay minerals was observed within two hours of cultivation. The specific growth rate of L. plantaruni 337D strain was in 5.2 times higher when cultured in MRS medium with 4 % of kaolinite and 6 times more - in MRS medium with 1 % montmorillonite versus control. The presence in the medium of kaolinite or montmorillonite slowed the process of reducing pH during growth of the L. plantarum 337D strain, compared with the control. In the presence of montmorillonite pH decreased more slowly than in the presence of kaolinite. The difference between initial pH value of medium with 4 % kaolinite and after two h (ApH) was 10 times less in comparison with the control. At the same time, pH of the medium with 1 % or 4 % montmorillonite began to decrease after 4 hours of cultivation.
Conclusions: Different effect on the growth of L. plantarum 337D strain due to differences of physical and chemical characteristics of kaolinite and montmorillonite used in the study.