Volatile Metabolites Emission by In Vivo Microalgae—An Overlooked Opportunity?

Abstract

Fragrances and malodors are ubiquitous in the environment, arising from natural and artificial processes, by the generation of volatile organic compounds (VOCs). Although VOCs constitute only a fraction of the metabolites produced by an organism, the detection of VOCs has a broad range of civilian, industrial, military, medical, and national security applications. The VOC metabolic profile of an organism has been referred to as its ‘volatilome’ (or ‘volatome’) and the study of volatilome/volatome is characterized as ‘volatilomics’, a relatively new category in the ‘omics’ arena. There is considerable literature on VOCs extracted destructively from microalgae for applications such as food, natural products chemistry, and biofuels. VOC emissions from living (in vivo) microalgae too are being increasingly appreciated as potential real-time indicators of the organism’s state of health (SoH) along with their contributions to the environment and ecology. This review summarizes VOC emissions from in vivo microalgae; tools and techniques for the collection, storage, transport, detection, and pattern analysis of VOC emissions; linking certain VOCs to biosynthetic/metabolic pathways; and the role of VOCs in microalgae growth, infochemical activities, predator-prey interactions, and general SoH.

Phytochemical study of the headspace volatile organic compounds of fresh algae and seagrass from the Adriatic Sea (single point collection)

“…VOCs biogeneration by microalgae, their occurrence, behaviour, ecological implications and industrial applications were described in 2016 [ 8 ]. The volatile metabolites emission by in vivo microalgae were reviewed in 2017 [ 9 ]. Tricyclic sesquiterpenes from marine origin were systematically presented in 2017 [ 10 ].…”

Using chemical language to shape future marine health

“…; Fink ), and the volatile metabolomes (ie volatolomes; Achyuthan et al . ; Steinke et al . ) should be considered in future efforts to decipher the marine chemical language.…”

“…Moreover, current methodological approaches frequently overlook volatile organic compounds that are well suited for bridging diffusion-limited communication gaps in the phycosphere (Pohnert et al 2007). Gases are produced in response to numerous biological processes (Steinke et al 2002;Fink 2007), and the volatile metabolomes (ie volatolomes; Achyuthan et al 2017;Steinke et al 2018) should be considered in future efforts to decipher the marine chemical language.…”

Low Molecular Weight Volatile Organic Compounds Indicate Grazing by the Marine Rotifer Brachionus plicatilis on the Microalgae Microchloropsis salina

“…The breadth of VOCs in aquatic systems, and specifically marine systems, and their ecological roles, by comparison, are not as well understood. In the absence of an algal bloom, microalgae present a unique analytical challenge for VOC discovery due to low natural aquatic concentrations of algal cells, high-salinity growth conditions, and integrated growth and dependence of microalgae on other microbial systems [ 4 ]. Algal mass production systems provide an opportunity to study in vivo VOC production without being limited to the study of algal blooms.…”

“…Furthermore, these studies might inaccurately suggest VOCs generated by living or stressed algal cultures due to VOC generation and sampling methodologies that rely on centrifuging, heating, or otherwise agitating the algal cells to produce a detectable chemical signal. Very few studies have focused on in vivo headspace sampling of algal cultures and even fewer have assessed VOCs generated by algae in the presence of a biotic stressor (for a more comprehensive review of algal VOC sampling, production, analysis, see [ 4 ]). Our methods are more similar to the purge and trap methods in which cultures are sparged with a stripping gas and the volatiles are concentrated from the gas stream on a sorbent trap prior to elution and analysis.…”