Amylase Enzyme Production in Bacteria Associated with Marine Macroalgae: Screening, Optimization and Biofilm Inhibitory Activity

Bacteria associated with marine macroalgae are considered a promising source for secondary metabolites and industrially significant enzymes. Amylases, which are commercially important enzymes mainly isolated from microorganisms, exhibit antibacterial, anti-inflammatory, anti-viral and antibiofilm activities. In this study, bacteria associated with the green macroalga Ulva fasciata were explored for amylase enzyme production, optimization and antibiofilm activity against marine biofilm-forming bacteria. A total of 12 amylase-producing bacterial strains were obtained from the alga. Among the strains, strain MD02 showed higher amylase activity (138.2 U mL−1) and strong biofilm inhibitory activity (89.5% inhibition). Molecular identification of strain MD02 showed similarity with Bacillus sp. The parameters influencing amylase production were initially tested using the traditional approach (one factor) followed by a two-level full factorial design and central composite design combined with response surface methodology. Results of statistical optimization showed a higher amylase yield (307.1 U mg−1) at pH 7.5, 0.75% inoculum and 0.7% glucose. This study advances our knowledge of the significance of Ulva-associated marine bacteria as a source of amylase enzymes and an effective biofilm control agent. Overall, this study highlights the potential significance of marine-algae-associated bacteria for enzyme production and demonstrates the feasibility of cost-effective amylase enzyme production using low-cost substrates.