Fig. 2.

A diagram illustrating the free exchange of resources, the negative and the positive interactions between microalgae and bacteria facilitated through the free exchange of nutrients or signal molecules and quorum sensing. Where, the dissolved organic matter (DOM), the cell degrading product (CDP), tryptophan and thamin originated from the microalgae and then assimilated and act on bacteria, while indole acetic acid (IAA), vitamins, siderophores, acetate, lytic enzymes originated from bacteria then acted on microalgae, and the quorum sensing can be applied within bacteria or between bacteria and microalgae facilitating the interactions. The illustration depicted is based on [27,60].