# Marine Bioactives and Their Application in the Food Industry: A Review
## 2 Marine Sources of Bioactive Molecules
### Marine Bacteria  
Among marine microorganisms, many species of gram-negative and gram-positive bacteria, fungi, archaea, and cyanobacteria are considered to be EPS producers in the marine environment. When considering marine bacterial species, _Pseudoalteromonas_ sp., _Pseudoalteromonas_ sp., _Pseudoalteromonas_ sp., _Pseudoalteromonas_ sp., and _Vibrio_ sp. are the major heteropolysaccharide producers. Table 1 reports several gram-positive and gram-negative bacteria present in the marine environment and their functions. Bacterial EPSs are widely used in numerous fields, such as medicinal, food, and other industrial applications, including heavy metal removal and oil recovery [22]. Their properties, such as thickening, coagulation, adhesion, stabilization, and gelling, enhance their potential application in various sectors. Due to novel combinations of EPSs and their structurally diversified nature, they play a vital role in the pharmaceutical industry. For example, \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Bacteria Species** & **Strains Producing EPSs** & **Characteristics of Exopolysaccharide** & **Functions** & **References** \\ \hline \multirow{4}{*}{_Basellus_} & _Basellus_ B3-15, _Basellus_ B3-72, _Basellus licheniformis_, and _Basellus thermoantticus_ & Different types of EPSs, consisting of tetra saccharide repeating units or structurally different EPSs consisting of trisaccharide repeating unit with a mannopyranoside configuration_ & Antiviral and immunomodulatory & [15; 16; 18] \\ \cline{1-1} \cline{2-4}  & _Halomonas_ & _Halomonas_ sp. TG39 & Heterogenous polymer & Emulsifying activity & [19] \\ \cline{1-1} \cline{2-4}  & _Planococcus_ & _Planococcus_ & _Pianococcus_ & Contained carbohydrate, protein, uronic acid, and sulfate & Emulsifying activity & [20] \\ \cline{1-1} \cline{2-4}  & _Enterobacter_ & _Enterobacter cloace_ & Acid polysaccharide which contained high amount of uronic acid, fucose, and sulfate & Emulsifying activity & [19] \\ \cline{1-1} \cline{2-4}  & _Alteromonas_ & _Alteromonas_ sp. 1545 & Contained glucose, galactose, glutonic acid, galacturonic acid, and 4,6-0-(1-carboxyithidine)-galactose & Antiviral activity & [21] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Exopolysaccharides produced by different bacterial species. antitumor, antiviral, and immunostimulant activities in polysaccharides produced by marine Vibrio and Pseudomonas, _Bacillus_ licheniformis, and _Geobacillus thermodenitrificans_ produced EPSs, which are considered to be immunomodulatory agents [19]. In addition to their pharmaceutical applications, EPSs can be used as gelling agents and exhibit preferred thermal stability and clarity. Moreover, their participation in removing heavy metals also plays a vital role in marine microorganisms' EPSs when it comes to environmental pollution. EPSs produced by the marine bacterium _Zooglea_ sp. have been identified as adsorbents of metal ions such as chromium, lead, and iron in a solution resembling a natural environment and remove these types of pollutant and toxic elements [22; 23]. Nevertheless, the emulsification and surface-active properties of EPSs have attracted attention for bioremediation and oil recovery. Apart from the above bacterial species, lactic acid bacteria (LAB) also play a major role in producing EPSs and have a better potential to be applied in foods. Lactobacillus can produce diversified EPSs and are popular for their application in fermented food products as texturing agents. Their role in dairy products is explained in the literature to be due to their contribution to the consistency and rheology of fermented milk products. Besides, lactobacillus are well-known as bacteria that are generally recognized as safe (GRAS), which may help their application in food product development [23; 24]. On the other hand, marine actinobacteria are considered one of the emerging secondary metabolite producers among marine microorganisms, which have gained much industrial attention.