Abstract:Fermentation industry, as an important part of biotechnology industry, covers a large proportion in industry in China. However, microorganisms face serious osmotic stress at the late fermentation stage as a result of the accumulation of microbial metabolites, neutralizers, and supplements, which seriously affects the growth of cells and the production of target product and thus results in low fermentation efficiency and low yield of target product. This paper aims to summarize and analyze cell structure, response pathways, genes, proteins, metabolism, and division of microorganisms in the presence of hyperosmotic stress, and to sum up potential measures against osmotic stress based on the characteristics of microorganisms and the current available techniques: strain improvement, addition of protective agent, improvement of neutralizers, removal of osmotic inhibitory factors, and membrane filtration technology. In summary, this study is expected to serve as a reference for raising the production in fermentation industry, saving energy, and reducing waste emission and cost.