Abstract: Lead is a kind of heavy metal which is a cumulative toxicity to human/animal body, and may lead to visceral organs damage, and confusion on immunity and central nervous systems. With the development of industrial economy and the changes of human livelihood, pollution is almost unavoidable, and even worsened. So it is of grest importance to investigate the effective methods for secondary-control strategy against the pollution. In this paper,some specific, namely were screened out three microbes Saccharomyces cerevisiae(YWL05), Rhodospirillum and Lactobacillus bulgaricus as safety microbes by using in vitro simulation test. Then the screened microorganism, Saccharomyces cerevisiae, with its adsorption rate achieving 96%, and the anti- pollution action of the two parts of Saccharomyces cerevisiae, or the polysaccharide, and intracellular proteins, were assayed by in vitro simulation test. Results showed that the polysaccharide performs a significant lead affinity with the adsorption effect up to 111.04 mg/g. The investigations of this paper demonstrated that S.cerevisiae polysaccharide exerts a significant action to adsorb lead and is the main component of lead-adsorption of S.cerevisiae. This bio-activator is expected to become a perfect functional feed additive to offer a new possible means of secondary-control agent for anti-lead-pollution.

Key words: lead pollution, biologic activator, lead adsorption, S.cerevisiae polysaccharide