Impact of Microalgae-Bacteria Interactions on the Production of Algal Biomass and Associated Compounds

Abstract

A greater insight on the control of the interactions between microalgae and other microorganisms, particularly bacteria, should be useful for enhancing the efficiency of microalgal biomass production and associated valuable compounds. Little attention has been paid to the controlled utilization of microalgae-bacteria consortia. However, the studies of microalgal-bacterial interactions have revealed a significant impact of the mutualistic or parasitic relationships on algal growth. The algal growth, for instance, has been shown to be enhanced by growth promoting factors produced by bacteria, such as indole-3-acetic acid. Vitamin B12 produced by bacteria in algal cultures and bacterial siderophores are also known to be involved in promoting faster microalgal growth. More interestingly, enhancement in the intracellular levels of carbohydrates, lipids and pigments of microalgae coupled with algal growth stimulation has also been reported. In this sense, massive algal production might occur in the presence of bacteria, and microalgae-bacteria interactions can be beneficial to the massive production of microalgae and algal products. This manuscript reviews the recent knowledge on the impact of the microalgae-bacteria interactions on the production of microalgae and accumulation of valuable compounds, with an emphasis on algal species having application in aquaculture.

Tetraselmis suecica F&M‐M33 growth is influenced by its associated bacteria

“…Stimulation of algal growth by bacterial communities or bacterial isolates has also been widely reported (Suminto and Hirayama, 1997;Arora et al, 2012;Amin et al, 2015;Cho et al, 2015;Fuentes et al, 2016). This may occur through different mechanisms, among which nutrient regeneration, release of trace elements and vitamins (particularly vitamin B 12 ) or of stimulatory compounds, enrichment of CO 2 and consumption of excess O 2 , or scavenging of reactive oxygen species in the algal microenvironment (Mouget et al, 1995;Croft et al, 2005;H€ unken et al, 2008;Natrah et al, 2014;Cooper and Smith, 2015;Fuentes et al, 2016;Park et al, 2017).…”

“…This different behaviour may play an important role during the starvation of algal cultures, a condition often applied to favour the accumulation of storage products (oil/carbohydrate) for biofuel production Bondioli et al, 2012;Yao et al, 2012;Garnier et al, 2016). Bacteria, besides inhibiting algal growth due to competition for nutrients, may also release harmful compounds, such as algicidal molecules or exoenzymes (Amin et al, 2012;Natrah et al, 2014;Cooper and Smith, 2015;Fuentes et al, 2016;Ramanan et al, 2016).…”

Using agro-industrial wastes for the cultivation of microalgae and duckweeds: Contamination risks and biomass safety concerns

“…A question of particular interest regarding the growth of aquatic organisms in agro-industrial WaW is whether the various pathogens harboured by WaW may contaminate biomass and what are the mechanisms of contamination. There are numerous studies investigating the interaction of microalgae or duckweeds with bacteria (Fuentes et al, 2016;Underwood and Baker, 1991), viruses (Short, 2012) or protozoan grazers (Tillmann, 2004) and their symbiotic, antagonistic or parasitic relationships. However, there is insufficient direct evidence on whether microalgae or duckweeds might host human or animal pathogens.…”

Bacillus pumilus Marinos Inhibidores de la Fijación de Microalgas a Sustratos Artificiales

“…Se ha demostrado que hay bacterias promotoras del crecimiento microalgal y que viven en simbiosis con las microalgas, como por ejemplo producen ácido indol-3-acético y vitamina B12 que promueven el crecimiento microalgal. Además, mejora los niveles intracelulares de carbohidratos, lípidos y pigmentos de las microalgas (Fuentes et al, 2016). Futuras investigaciones deben hacerse para aclarar si el efecto inhibidor de las bacterias anti bioincrustantes como las encontradas en este trabajo, es sólo sobre la microalga o sobre el consorcio simbiótico afectando a las bacterias asociadas a las microalgas e indirectamente inhibiendo el crecimiento microalgal.…”