Within-species and temperature-related variation in the growth and natural products of the red alga Asparagopsis taxiformis

How to select algal strains as source of natural products for industrial-scale exploitation?

The red a l g a l genus Asparagopsis (Bonnemaisoniaceae) is a significant resource for bioactive natural products. However, prior to domestication for commercial production, we need to understand the potential variation in growth and concentration of natural products between isolates of Asparagopsis and, beyond that, how these traits are affected by environmental conditions. Ten isolates of Asparagopsis taxiformis were collected from tropical and warm-temperate regions in Queensland, Australia, and identified by molecular barcoding of the mitochondrial intergenic spacer (cox2–3 spacer). The isolates were cultured at three temperatures ranging from the minimum of the warm temperate region to the maximum of the tropical region. Growth rates and the concentration of natural products varied between the region of origin, between isolates within region and between temperatures. Growth differed by up to 50% between isolates, whereas the concentration of natural products differed more than tenfold. Growth rates were highest at the minimum temperature of 20.2°C, irrespective of region of origin, and were lowest at the maximum temperature of 28.1°C. Natural products were threefold higher in tropical isolates, and this variation was not correlated to growth. Consequently, targeting isolates with high concentrations of natural products should be the primary strategy for the domestication Asparagopsis for biotechnology applications. Read the full paper here!

Our SOUL Evolution paper on the front cover

Our recent paper "Evolution of the SOUL Heme-Binding Protein Superfamily Across Eukarya" by Antonio Emidio Fortunato, Paolo Sordino and Nikos Andreakis has appeared on the front cover of the June 2016, Volume 82, Issue 6 of the Journal of Molecular Evolution. Well done!

Evolution of the SOUL Heme-Binding Protein Superfamily Across Eukarya



SOUL homologs constitute a heme-binding protein superfamily putatively involved in heme and tetrapyrrole metabolisms associated with a number of physiological processes. Despite their omnipresence across the tree of life and the biochemical characterization of many SOUL members, their functional role and the evolutionary events leading to such remarkable protein repertoire still remain cryptic. To explore SOUL evolution, we apply a computational phylogenetic approach, including a relevant number of SOUL homologs, to identify paralog forms and reconstruct their genealogy across the tree of life and within species. In animal lineages, multiple gene duplication or loss events and paralog functional specializations underlie SOUL evolution from the dawn of ancestral echinoderm and mollusc SOUL forms. In photosynthetic organisms, SOUL evolution is linked to the endosymbiosis events leading to plastid acquisition in eukaryotes. Derivative features, such as the F2L peptide and BH3 domain, evolved in vertebrates and provided innovative functionality to support immune response and apoptosis. The evolution of elements such as the N-terminal protein domain DUF2358, the His42 residue, or the tetrapyrrole heme-binding site is modern, and their functional implications still unresolved. This study represents the first indepth analysis of SOUL protein evolution and provides novel insights in the understanding of their obscure physiological role. Reed full paper here!