Essential Science: New types of microbial life in the oceans

Posted Oct 3, 2016 by Tim Sandle
The seas and oceans of the world make up the majority of the surface and less is known about life in the oceans compared with the surface of the moon. New research has revealed the mysteries of oceanic microbial life.
DEP’s chemists use a liquid chromatography tandem mass spectrometer to measure algal toxins.
DEP’s chemists use a liquid chromatography tandem mass spectrometer to measure algal toxins.
Florida Department of Environmental Protection
There are several interesting new developments in relation to microbial life in the oceans and the information informs about the health of the oceans and other useful ecological information.
The first development is that mathematicians have discovered a key understanding about the constantly changing distribution of microbial species in the world’s oceans. This overturns the conventional approach to studying microorganisms. Instead of classifying bacteria in terms of their taxonomy, the researcher suggests classifying them based on their biochemical function.
Researchers Stilianos Louca, Laura Parfrey and Michael Doebeli have been especially busy in recent years. The British Columbia scientists have classified over 30,000 different microbial species found across Earth's oceans. However, instead of meticulously classifying each isolated by species type, they opted to classify the microbes by 'functional groups.' This included using descriptors like phototroph (organisms that use light for energy) or sulfide oxidizer (organisms that eat highly toxic sulfide).
The advantage of this approach is that is allowed the scientists to predict the distribution of microbial functional groups based on physical and chemical variables. These variable so included ocean depth and temperature.
While this approach has proven more accurate it has revealed the vastness of microbial life in the oceans and its unpredictability in terms of distribution. The researchers also found the oceans to be a battle ground, with bacteria being infected by viruses or bacteria engaging in 'chemical warfare' with each other, factors that further accounted for the versatility in microbial distribution.
The British Columbia University findings are published in the journal Science, with the research paper headed “Decoupling function and taxonomy in the global ocean microbiome.”
Related to this the same research team has developed a mathematical model that integrates environmental and molecular sequence information to explain how microbial networks in the oceans drive nutrient and energy cycling in marine ecosystems. This important work could improve researchers' and policy makers' ability to predict how the world's marine microbial communities respond to climate change. This would also allow meaningful studies to be made on fisheries, biodiversity and climate.
Understanding how microbial processes contribute to nutrient and energy cycles in the ocean is vital in a time of climate change. The new model allows for more accurate projections of microbial processes with potential feedback on climate change and ecosystem health to be made.
The model is outlined in the journal Proceedings of the National Academy of Sciences, in a paper titled “Integrating biogeochemistry with multiomic sequence information in a model oxygen minimum zone.”
A second, and related, development comes from Ohio State University. Here new research suggests there are triple the number of viruses in the oceans compared with those that were previously known. Interestingly, the discovery could influence carbon reduction efforts.
The extent of ocean viruses has come from the recent Tara Oceans Expedition and an earlier 2010 Malaspina expedition. Both expeditions took thousands of samples for chemical and microbial analysis.
The outcome expanded our understanding of the number of different viruses found in the oceans. With this researchers cataloged 15,222 genetically distinct viruses and proceeded to group them into 867 clusters that share similar properties.
The carbon reduction aspect comes from the fact that the oceans soak up around half of the generated carbon. The effect of this is to acidify the oceans. This places some ocean-dwellers, like shellfish, at risk. It is thought that understanding how viruses interact is critical to management efforts to protect marine life. This is because viruses infect bacteria, and some of these bacteria are responsible for producing oxygen. Where conditions favor high numbers of viruses, then viruses play a role in modulating greenhouse gas emissions from the oceans.
This article is part of Digital Journal's regular Essential Science columns. Each week we explore a topical and important scientific issue. Last week we looked at a why some mosquitoes elect to bite people and other prefer other animals. The week before we discussed a new type of bacteria that can cause an anthrax-like disease together with some cases from Africa.