The microorganisms available for testing in the laboratory are mainly in the following four categories, many of which are related to the mildew of the coating.

​The advantages of non-oxidizing bactericidal algaecides are:

Waterborne pigments are very sensitive to microbial attack. In general, all organic pigments can be used by a variety of bacteria to become a source of carbon and nitrogen for bacteria. In all pigment tests, yellow pigments are most susceptible to microbial degradation due to organic components.

Bronopol is a class of high-efficiency, broad-spectrum preservatives with the following distinct advantages: Bronopol at a concentration of ppm can effectively kill bacteria

Modern papermaking mostly uses vegetable fiber cooking and pulping or pulp paper as the main raw material pulping process. Mortar is mainly caused by microorganisms, including filamentous bacteria from water, algae and mold in the air, and a large number of bacteria in waste paper. At the same time, a large number of chemical additives added in paper production, such as: Glues, starches, dyes and fillers are rich in nutrients, which provide abundant food for these microorganisms. In addition, the papermaking process can provide temperature and environment suitable for microbial reproduction, and microorganisms can grow and multiply once they are intervened. When microorganisms grow, they often adhere to the surface of the object (pipes, pool walls, etc. of the slurry process) to form biofilms