European Scientific Journal June 2019 edition Vol.15, No.18 ISSN: 1857 – 7881 (Print) e - ISSN 1857- 7431 1 Investigation of Bacillus pumilus and Staphylococcus haemolyticus adhesion on 304L Stainless Steel in Atmospheric Simulated Medium Amal El Aabedy, Saad Koraichi Ibnsouda, Omar El Farricha, Laboratory of Microbial Biotechnology, Faculty of Sciences and Technology, University Sidi Mohamed Ben Abdellah, Fez, Morocco Doi: 10.19044/esj.2019.v15n18p1 URL:http://dx.doi.org/10.19044/esj.2019.v15n18p1 Abstract The bacteria adhesion on materials surface is the first step to formation of biofilm that could lead to biocorrosion. This study aimed to investigate the correlation between bacteria adhesion and the physicochemical properties of both materials and bacteria in atmospheric simulated medium. The material used in this study is 304L stainless steel and Bacillus pumilus and Staphylococcus haemolyticus bacteria strains. The hydrophobicity, electron donor and electron receptor properties were determined by contact angle measurements. In addition, the bacteria capacity of adhesion was followed by using a scanning electron microscope. The contact angle measurements finding showed that both bacteria have hydrophilic surfaces qualitatively and qualitatively. Otherwise, the stainless steel has revealed a hydrophobic character qualitatively and quantitatively. Moreover, the scanning electron microscope displayed the high speed of adhesion of the studied bacteria. The contact angle measurements could be used as a mean to prevent biocorrosion caused by bacteria adhesion. Keywords: Adhesion, stainless steel, atmospheric simulated medium, biocorrosion Introduction Microbiologically Influenced Corrosion (MIC) or biocorrosion is an electrochemical phenomenon in which microorganisms adhere to the surfaces of metals or other materials. This adhesion can induce or accelerate corrosion reactions of these materials through the interfacial interaction with the metabolic activities of these microorganisms (Javaherdashti, 2016). This process of biocorrosion could be able to initiate, facilitate or accelerate