Since ancient times, humans have used animal skin in their daily lives to create shelters and clothing. They have also developed special techniques to preserve animal hides for a long time after slaughter, such as salting and cooling. Skin is an ideal environment for microorganisms to inhabit due to its temperature and moisture content. According to our knowledge, many factors, including pH, temperature, salt concentration, nutrition, etc., influence bacterial growth. Therefore, many bacteria can thrive in a wide range of NaCl concentrations, from 1% to 20%, and are classified accordingly. Despite the high concentration of NaCl in the soak liquor used in the preparation of leather, numerous bacterial species can readily grow and produce lipolytic and proteolytic enzymes as a form of metabolic activity. Lipolytic and proteolytic enzymes have negative effects on leather and leather products, including spotting, disagreeable odor, discoloration of the resultant leather, and consequentially significant economic losses. To overcome this obstacle, a variety of preventative measures have been implemented, including salting, the use of antibiotics, plant extracts (essential oils), and, more recently, electric currents.