Effects of bacterial communities on biofuel-producing microalgae: stimulation, inhibition and harvesting

Abstract

Despite the great interest in microalgae as a potential source of biofuel to substitute for fossil fuels, little information is available on the effects of bacterial symbionts in mass algal cultivation systems. The bacterial communities associated with microalgae are a crucial factor in the process of microalgal biomass and lipid production and may stimulate or inhibit growth of biofuel-producing microalgae. In addition, we discuss here the potential use of bacteria to harvest biofuel-producing microalgae. We propose that aggregation of microalgae by bacteria to achieve 490% reductions in volume followed by centrifugation could be an economic approach for harvesting of biofuel-producing microalgae. Our aims in this review are to promote understanding of the effects of bacterial communities on microalgae and draw attention to the importance of this topic in the microalgal biofuel field.

Seasonal Succession of Free-Living Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula

“…For example, some marine Flavobacteria, including Polaribacter , contain proteorhodopsin, a light-driven proton pump that can enhance growth in low-nutrient conditions, while Rhodobactaceae have been shown to carry out aerobic anoxygenic photosynthesis (Gonzalez et al, 2008; Kimura et al, 2011; Voget et al, 2015; Xing et al, 2015). Whether or not pre-summer changes in bacterial community composition are associated with bacterial feedbacks on phytoplankton growth is not known (Amin et al, 2012, 2015; Prieto et al, 2015; Wang et al, 2016). …”

“…However, there is increasing evidence that bacterial interactions with phytoplankton may influence the development of phytoplankton blooms themselves through bacterial production of key vitamins, chelating agents, or hormones that stimulate or impede phytoplankton growth (Amin et al, 2012, 2015; Prieto et al, 2015; Wang et al, 2016). Bacterial succession prior to the onset of phytoplankton blooms has been arguably under-studied (Moran, 2015; Needham and Fuhrman, 2016).…”

Phycospheric Native Bacteria Pelagibaca bermudensis and Stappia sp. Ameliorate Biomass Productivity of Tetraselmis striata (KCTC1432BP) in Co-cultivation System through Mutualistic Interaction

“…Microalgae have drawn extensive global attention for their possible application as third generation biodiesel production since some of them are rich in saturated and mono-unsaturated fatty acids (Green et al, 2015; Mitra et al, 2015; Patidar et al, 2016; Wang et al, 2016). In addition to generating huge biomass through low commercial nutrient inputs, it is essential to integrate feasible biofuel production with many allied products.…”

Removal of pharmaceuticals and personal care products from wastewater using algae-based technologies: a review

“…Algae also exude organic compounds such as carbohydrates and amino acids, which support the heterotrophic metabolism and provide substrates for the co-metabolism of organic contaminants (Battin et al 2016;Tran et al 2013). Bacteria in turn accelerate the regeneration of nutrients and trace elements, and release phytohormones to promote algae growth (Dang and Lovell 2016;Wang et al 2016a). Interactions between algae and bacteria can also be completive.…”

“…Competition for nutrients and spaces has been observed in many nutrient-limiting environments Rier and Stevenson 2002;Scott et al 2008), but may not be the case in wastewater. Algae can raise water pH, increase dissolved oxygen content during photosynthesis, and release inhibitory chemicals, which can be detrimental to certain bacteria, while bacteria can in turn affect algae by killing or lysing or by changing the microenvironment (Amin et al 2012;Subashchandrabose et al 2011;Wang et al 2016a). However, how microbial interactions affect the overall biodegradation ability of the consortia remains poorly understood.…”