The Effects of heavy metals and calcium chanal blockers on bacillus subtilis's growth, plasmid and amylase secretion

VI Summary In this study, B. subtilis was used, obtained from Nottingham University, Medical School in Microbiology Department and Ankara University, Agriculture Faculty, Food Engineering Department. It has been established that Nutrient Broth (NB) and Starch Beef (SB) are more convenient media in terms of the growth of the bacteria. The maximum activity time for a-amylase secretion was determined by the activity determination method. These results were confirmed by electrophoresis. Bacteria was interacted with various calcium canal blockers in the SB liquid medium. The effects of blockers on the bacterial growth, a-amylase production and bacterial plasmids were investigated. It has been established that bacterial growth and a-amylase secretion were inhibited by blockers. Calcium canal blockers had no effect on the a-amylase in in vitro. Bacteria was interacted with Diltiazem, a calcium canal blocker, along control experiment in the SB liquid medium in the presence of heavy metals, and their effects on bacterial growth, a-amylase production and bacterial plasmids were investigated. Bacterial growth and a-amylase secretion were inhibated by HgCİ2, but not by ZnCk. Diltiazem alone did not show any effect on the plasmid, however, both heavy metals caused plasmid amplification in the presence of Diltiazem. The protein synthesis was blocked by adding Chloramphenicol in the NB liquid medium at a certain period of the bacterial bacterial growth. The durations of a- amylase synthesis and of its maturation in terms of the enzyme activity on membrane and of the secreted enzyme activity were determined. The time for the excretion through membrane along ribosome following completed inhibition was measured as a 70-80 minutes. The effect of pH on the neutral protease activity was determined. The enzyme showed maximum activity at pH 7. It was observed that Zn2+, its prostetic group, was not removed during dialysis. The enzyme loses its activity because of the degeneration of its three dimensional structure at pH's deviated from optimal range.