Abstract
Antimicrobial activity is defined as the ability to destroy or inhibit the
growth of microorganisms. Antimicrobial compounds are naturally occurring or
synthetic organic compounds having antimicrobial activity. Recently, scientists have
discovered many pharmaceutically active compounds that have antibacterial,
antifungal, antiviral and antiprotozoal activities in seaweeds. To thrive in various
environmental stresses, seaweed produces different metabolites such as polyphenols,
polysaccharides, proteins, fatty acids, and pigments. These bioactive compounds are
responsible for the antimicrobial activity exerted by seaweed. The antimicrobial
activity of seaweed is influenced by various factors, such as the type of seaweed extract
used, the target microorganisms, and the environmental conditions. The composition of
the bioactive compounds from seaweed may depend on the extraction method and the
solvent. It also depends on the seaweed sample, such as fresh or dried sample. Different
mechanisms are followed by seaweed extract to acquire antimicrobial activities.
Seaweed extracts exhibit various inhibition mechanisms, including disruption of the
cell membrane, inhibition of target microorganism enzymes, and prevention of
microorganism association with cellular receptors of the host cell. The location,
salinity, temperature, etc. of the marine environment may affect the chemical
composition of the bioactive compounds present in the seaweeds. The antimicrobial
activity of seaweed can be evaluated in both in vitro and in vivo assays. Antimicrobial
susceptibility tests and antimicrobial resistance tests are carried out by in vitro
methods. The antimicrobial activity of seaweed can be a promising source in many
applications, such as therapeutic applications, food industries, aquaculture, and
biofouling.