Why work on Algae
Algae are an extremely diverse category of unrelated photosynthetic organisms and include the most prolific primary biomass producers on the planet. They represent promising biofactories for the production of commercially important nutrients (including vitamins A, C and E and polyunsaturated fatty acids) and industrially important chemicals (including astaxanthin and polyphenols). Various algae make complex natural product toxins, including some of the most poisonous small molecules known and enormous cyclic polyethers, compounds not found in bacteria and fungi. The few genomes available suggest there is a great, unexplored potential encoded by these algae. Algae also form complex symbiotic relationships with certain bacteria, exchanging fixed carbon for vitamins, with important implications in water-ways management and aquaculture. There is some evidence for species-specific interactions between bacteria and algae, but the chemical ecology of these cross-kingdom microbiomes remains unclear.
What are Euglena
Euglena are a class of eukaryotic microalgae that are found commonly in fresh water throughout the world, and are responsible for forming green scum on nutrient rich ponds and puddles. They show characteristics of both plants and animals, while in evolutionary terms are most closely related to the protozoan parasites Trypanosoma and Leishmania. Euglena are able to grow using both photosynthesis and by absorbing nutrients from the surroundings and have enormous metabolic capacity, able to make many vitamins, nutrients and bioactive carbohydrates, and are being explored for their uses as both nutritional additives and biofuels. The unique metabolism of Euglena has led to them being used in the Eu:CROPIS biological life support systems for growing plants in different levels of gravity on Mars and the Moon.
Importantly, only 40% of the sequences in the transcriptome could be annotated, suggesting there is a huge untapped capability in this organism that is completely unknown that can be expected to give rise to new and unpredictable biology and chemistry.
The complexity of the algal genome and their novel genes means genome guided natural product research is not a plausible route to discovering new algal natural products. Rather than emulating bacterial and fungal genomics approaches, we are using new chemoinformatic methods to directly look for novel natural products in microalgae. The key enabling technology for this research is mass-spectrometry based molecular networking, which allows the computational analysis of complex cell extracts. This is operated through the GNPS pipeline, which rapidly links similar metabolites based on both mass and fragmentation patterns. This technique also identifies known compounds, helping to identify new molecules and avoid rediscovery. This is particularly good for high throughput comparisons of multiple extracts to identify unique and unknown compounds, and we have previously used it to analyse 146 bacterial species form a range of growth media and for environmental samples. This technique allows us to select samples that contain the most interesting and novel compounds for further work.