Effects of some heavy metals (Zn, Cu, Mn, Al, Li) on growth of Bacillus thuringiensis var Israelensis

Factors affecting the organisms outside from their natural environment are known as stress factors. These factors affect all parts of the ecosystem differently. Microorganisms are frequently exposed to these factors in their life cycle because they are a very important component of the ecosystem. Besides, the adaptation mechanisms which developed against stress factors constitute one of the remarkable issues related to this living group. Bacteria have a very important place in biotechnological studies because of these properties. Biotechnological studies shed light on studies that are closely related to the future, such as agriculture, the food industry, medicine and the environment. In this study, the bacteria Bacillus thuringiensis var. israelensis (Bti) an effective entomopathogen, isoleted from the soil were used. It was aimed to calculate the likelihood of maintaining the effectiveness of Bti against the amount of chemical waste (0.01 M, 0.05 M, 0.1 M, 0.5 M) in the soil. Sports and vegetative cell viability of the Bti strain were determined by colony counts at 12, 24 and 48 hours with bacterial treatments of certain concentrations of heavy metals such as manganese, iron, aluminum, zinc and lithium. Protein weights were calculated by SDS PAGE at indicated periods of the bacterial solutions exposed to stres with different chemistries at 24 and 48 hours. Likewise, phase-contrast microscope views were examined for each chemical for each hour period at 24 and 48 hours. Lithium activity in the obtained findings has found that Bti maintains its spore and vegetative cell viability at all concentrations, after 0.01 M, manganese and aluminium activity are losing one's viability, causing the copper and zinc bacteria to lose their full vitality. Keywords: Bacillus thuringiensis var. israelensis, heavy metal, bakterial stress, biotechnology, SDS PAGE, spore viability, lithium, zinc