Enhanced Production of Astaxanthin and Zeaxanthin by Paracoccus Sp. LL1 Through Random Mutagenesis.

Astaxanthin, a high-value carotenoid with potent antioxidant and anti-inflammatory activities, is increasingly in demand in various industries. This study reports the successful enhancement of astaxanthin and zeaxanthin production in Paracoccus sp. LL1 through random mutagenesis using ethyl methanesulfonate (EMS). To induce genetic diversity, EMS mutagenesis was employed, followed by the selection of mutants that exhibited increased carotenoid production. The top-performing mutants showed a significant 2.76-fold increase in astaxanthin and a 10.14-fold increase in zeaxanthin compared to the wild-type strain when treated with the optimal EMS concentration of 0.5%. The effects of initial glucose concentration and inoculum size on astaxanthin and zeaxanthin production were evaluated, and production was higher when glucose was 2% and inoculum size was 10%. Our findings demonstrate the potential of Paracoccus sp. LL1 as a promising alternative to traditional astaxanthin-producing organisms, such as Haematococcus pluvialis, offering advantages including faster growth, simpler cultivation requirements, and genetic tractability. This approach not only enhances carotenoid production but also highlights the novelty of using Paracoccus sp. LL1, a less-explored strain, for high-yield production of both astaxanthin and zeaxanthin. These results suggest that Paracoccus sp. LL1 could serve as an efficient platform for industrial-scale carotenoid production through metabolic engineering and random mutagenesis, providing a viable alternative to current production systems.