[Study on the mechanism of the interaction between montmorillonite and bacterium].
OBJECTIVE
To investigate the mechanism of the interaction between montmorillonite and bacteria by studying the reactions of different charges of montmorillonites with bacteria.


METHODS
Bacteriostatic test: one loop of E. coli and Staphylococcus aureus at the concentration of 1 x 10(6).mL-1 was incubated to the plate culture medium containing different concentrations of montmorillonite, and incubated 24 h to observe the growth of bacteria. Bacterial adsorptive test: different amounts of montmorillonite were added into the artificially simulated intestinal solution (containing bacteria 1 x 10(7).mL-1). After the culture, the bacterial colonies were counted.


RESULTS
The results showed that montmorillonite per se showed no bacteriostatic or bactericidal effect, but after exchange with metal ion and functional groups which inhibits bacteria, then it showed these activities. Adsorption was the main way between montmorillonite and bacteria. The special way of fixing bacteria into the "carriage" of montmorillonite gel which carry this structure was its pharmacological basis of curing diarrhea. The adsorption effect was related to layer charge density of the montmorillonites.


CONCLUSIONS
Montmorillonite showed adsorption ability of bacteria with minus related to its layer charge, but has no bacteriostatic and bactericidal effect.
Hu
Xiu-rong
XR
Center of Analysis and Measurement, Pharmaceutical College, Zhejiang University, Hangzhou 310028, China.
Lu
Guang-lie
GL
Chen
Lin-shen
LS
Gu
Jian-ming
JM
Zhang
Yue
Y
D000327:Adsorption; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D001546:Bentonite / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D013211:Staphylococcus aureus / Q000187:drug effects*
D000897:Anti-Ulcer Agents; D001546:Bentonite