Optimization of Ectoine Production by Marinococcus sp. Isolate using Defined Media: The Role of NaCl and L-Glutamate as Key Factors

Introduction: Ectoine, a compatible solute with exceptional protective properties against osmotic and environmental stress, has wide-ranging applications in cosmetics, pharmaceuticals, and agriculture. Its biosynthesis is primarily linked to halophilic and halotolerant microorganisms. Within this context, Marinococcus sp. has emerged as a promising candidate due to its natural adaptation to saline habitats. Despite its potential, systematic optimization of ectoine production in this genus remains underexplored. This study aimed to optimize ectoine production by Marinococcus sp. isolate, with a focus on the influence of NaCl and L-glutamate concentrations. Statistical approaches, Plackett Burman Design (PBD) for factor screening and Response Surface Methodology (RSM) for interaction and optimization, were employed to enhance production efficiency. Materials and Methods: A defined medium was formulated to test the effect of various nutritional and environmental factors. PBD was applied to identify critical variables influencing ectoine yield, while RSM further refined NaCl and L-glutamate concentrations. Quantification of ectoine was performed using UV–Visible spectroscopy and HPLC, and statistical validation was supported by a regression coefficient (R2) of 93.19%. Results: NaCl and L-glutamate were identified as the most influential factors, exhibiting a synergistic effect on ectoine biosynthesis. Optimal concentrations led to a significant increase in ectoine yield, while carbon sources contributed minimally, corroborating previous findings. Discussion: This study optimized ectoine production by Marinococcus sp., highlighting NaCl and L-Glutamate as key factors. Their synergistic effect significantly increased ectoine yield, while carbon sources had minimal impact. The high regression coefficient (93.19%) validated the optimization process, suggesting the potential for large-scale ectoine production in industrial applications. Conclusion: This study highlights the effectiveness of PBD and RSM in optimizing ectoine production and positions Marinococcus sp. as a cost-effective candidate for industrial-scale applications in pharmaceuticals, cosmetics, and agriculture.