Optimization of alginate lyase production using Enterobacter tabaci RAU2C isolated from marine environment by RSM and ANFIS modelling.

Alginate lyases are enzymes that hydrolyze alginate polysaccharides. Alginate lyase finds application as a biocatalyst in the production of biochemicals and biofuels and, as an agent in the control of alginate fouling. Furthermore, alginate lyases could be used as potential therapeutic agents for treating P. aeruginosa infections, notably in the treatment of cystic fibrosis by disruption of alginate biofilm and therefore enhancing the efficacy of anti-pseudomonal antibiotics. However, the commercial application of the enzyme is constrained due to high production costs and poor productivity. This issue could be addressed by employing high-yielding strains, optimizing the process parameters and media, and controlling systems. Marine microbes are known to produce alginate lyase for the utilization of seaweed alginate. In this perspective, different sponges and seaweeds were collected from Tuticorin, Gulf of Mannar, Tamilnadu, India, and primarily screened for alginate-degrading bacteria using Gram's Iodine method. Further screening of potential isolates was done by evaluation of alginate lyase activity using DNS assay. The potential marine bacterium was identified as Enterobacter tabaci RAU2C using biochemical tests followed by 16S rRNA sequencing. The initial pH for the production of alginate lyase was optimized. The Plackett–Burman design was used to screen nitrogen and mineral sources for the production of alginate lyase. Central Composite Design was formulated using Design Expert software for five variables to optimise the concentration of media components. Response Surface Methodology was used to estimate optimal concentrations, which were then confirmed by experiments. ANFIS modelling was established using MATLAB to further analyze and predict the composition of variables for enhancing enzyme activity. The optimized media constituents were found to be sodium alginate-5 g/l, peptone-15 g/l, ammonium sulfate-8 g/l, sodium chloride-30 g/l, and dipotassium hydrogen phosphate 4 g/l with an enzyme activity of 12.5 U/ml. Furthermore, the process parameters such as production time, inoculum volume, and age of the inoculum were also optimized for maximizing the alginate lyase production. [ABSTRACT FROM AUTHOR]