Abstract

Ultraviolet (UV) radiation generates cyclobutane pyrimidine dimer (CPD) photoproducts in the DNA of skin cells, causing photoaging and non-melanoma skin cancer. Photoproducts can be repaired by the CPD-photolyase enzyme. The main source of CPD-photolyase is the cyanobacterium Synechococcus sp, from which a protein extract containing the enzyme is obtained, encapsulated, and included in skincare products. Thus, this work focused on the production (induction and recovery) of CPD-photolyase from the cyanobacterium Synechococcus leopoliensis. For this, variation in culture light conditions and extraction by Aqueous Two-Phase System (ATPS) were evaluated. Results showed an increase in specific CPD-photolyase activity during the stationary growth phase. Induction of CDP-photolyase under high light intensity and UVA irradiation was obtained. During downstream bioprocessing, centrifugation harvesting method preserves the enzyme activity, whereas the autoflocculation decreases it drastically. ATPS was used for the first time in the extraction of CPD-photolyase, allowing a one-step extraction from the biomass. The best ATPS condition was 15% PEG1000/18% phosphate (pH 7.0), where CPD-photolyase was partitioned to the PEG phase using both protein extract and wet biomass. Moreover, this ATPS also extracted c-phycocyanin in the PEG phase, which has important bioactivity properties and could complement skincare products based on CPD-photolyase. Overall, this bioprocess was successfully able to produce a CPD-photolyase rich PEG solution with an activity yield of 27.5 +/- 2.6 mM g(-1) dry biomass, similar to 5.5 times higher than in the protein extract. This PEG solution can be used for further CPD-photolyase purification or directly for skincare product development.