Effect of Lithium on Growth Process of Environmental Microorganism by Microcalorimetry and SEM

Abstract

Bacillus thuringiensis (BT) was the typical environmental microorganism.To explore the environmental behavior of lithium, the growth metabolism of BT under Li+ was investigated by microcalorimetry. The power-time curve showed the growth metabolic power-time curve of BT was divided into the bacterial growth phase and sporulation process. Lithium at 0.1-12mmol L-1 revealed no obvious effect to the bacterial growth phase of BT . Li+ at 0.1-4mmol L-1 stimulated the sporulation production and Li+ at 12-16mmol L-1 inhibited that respectively. While the time for initiation to produce sporulation was not influenced. However, the time for initiation to produce sporulation was earlier than the control induced by 8 mmol L-1 of Li+. The interest turning point of microcalorimetric result was confirmed by the following SEM detection. Besides the proof on environmental behavior of lithium, present results may bring related information for BT spores biological engineering transformation.