Our skin is the largest organ that covers our body against the external environment and it is in constant contact with microorganisms compared to our other organs. The bacterial infection does not develop easily on our skin due to many protective factors. However, bacterial infections occur when there is a deterioration in any of these protective mechanisms. Therapeutic plants and spices are widely used as antibacterial agents for dermatological use. In this study, it is aimed to prepare a microemulsion loaded with bioactive sumac extract and to test bioactivity of microalgae (Chlorella sp.) commonly used in cosmetic formulations by using an innovative approach. The microcomposites prepared by this method are expected to have a better effect on fat, bacteria and toxins on the surface of skin. Sumac fruit (Rhus coriaria), which is used as a spice, was extracted by using ethanol in Soxhlet apparatus. Algae-microcomposites were prepared with different amounts of sumac extract (1%, 2% and 3% (w/v). Excess of ethanolic extract of sumac fruit was mixed in 3 ml oleic acid for 72 hours at 37°C and and the insoluble fraction was removed by centrifugation. Tween 80 was added to the solution as a surfactant and PEG-400 was added as a co-surfactant at 2: 1 ratio into the solution. While the mixture was stirred at the medium intensity on the magnetic stirrer, pure water was added dropwise over solution until a homogenous clear solution was obtained. The bioactivity tests of the microcomposites were carried out using gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacteria which are generally found on the skin surface. Microcomposites containing 2 % and 3 % sumac extract showed bioactive properties by inhibiting the growth of S. aureus and E. coli bacteria.