Researching the smallest organisms in the ocean

Interview with prof. Lucas J. Stal (NIOZ and UvA), MaCuMBA coordinator

Can you explain to a wider audience, whose knowledge of marine microorganism may be limited, why a project like MaCuMBA is important?
Most people when they hear about microorganisms think of dirt, of illness, or at best they know that microorganisms make our beer, wine, yoghurt, cheese, antibiotics, etc. Few people realize that the total biomass of microorganisms on earth is many times higher than that of all other organisms together, including man. Few people know that the genetic diversity of microorganisms is overwhelmingly larger than that of all plants and animals together and that the number of species is unknown but must be in the many tens of millions.

Most people don’t care that only 10,000 species have been described. But they should! Mankind has used microorganisms for various applications (how many millions of lives have been saved due to the discovery of penicillin?); how many new applications (medicine, food, energy, clean-up of contaminants and xenobiotic compounds) are hidden among the perhaps 99.99% unknown microorganisms?
Perhaps more abstract tot most people is the fact that the world was microbial for 3,200 million years and that macroorganisms have been around only for the last 600 million years (and man for only 3 million years). How many people realize that the oxygen in our atmosphere originates from microorganisms and that half of the oxygen we breathe today is produced by microorganisms? Microorganisms rule this planet; they did 3.8 billion years ago and still do today. They are responsible for the functioning of all ecosystems on earth and form the basis of the food web. But our knowledge of these processes is very limited.

In what ways could research form MaCuMBA eventually benefit society?
We are facing unprecedented global changes, increase in temperature, acidification of the ocean, energy and food crises. In order to understand these processes, predict the consequences and search for solutions we need to substantially increase our knowledge of the unknown majority of microorganisms and their properties. Yet, we have no idea how to isolate, cultivate and describe this unknown majority, at least not at the rate and cost that is necessary to bring any application in reach within the next decades, when we will need them most.

MaCuMBA focusses on marine microorganisms. Why focus on the marine?
Well, 70% of the surface of this planet is covered by the ocean. If we take into account that the average depth of the ocean is 4 km, we are dealing by far with the largest continuous ecosystem on Earth. All together it is estimated that 10²⁹ microorganisms live in the ocean. That is a number with 29 zeros? As it is difficult to imagine such a large number we can say that in every milliliter of seawater live 1 million microorganisms and perhaps thousands of species.

Also, the sea is not homogeneous. It contains underwater salt lakes, volcanos, mounts, hot smokers and cold seeps and many more extreme environments in which many types of specialized microorganisms live. Also the abyssal deep sea with low temperatures, unimaginable high pressure and without light is an unexplored environment. The seafloor (from coastal intertidal sediments to the deep sea) is a habitat of undreamed of high numbers of microorganisms but is hardly ever explored.

The sea is full of higher organisms (mostly animals but also plants such as sea grasses), each carrying their own flora of microorganisms. We expect that we will find a wealth of new microorganisms. There is another reason why we focus on the sea. Freshwater is in ever limiting supply. If we want to use  microorganisms for biotechnological purposes we will have to grow them. It is an advantage that we can grow them in seawater rather than using dwindling freshwater resources.

In terms of the project itself, can you outline how the collaborative element between the partners will work?
The consortium members were chosen because of their expertise and because their skills are complementary to each other. Hence, we have groups that specialize in specific groups of organisms or environments. Other groups have access to ships (such as NIOZ) or have developed hardware that can be used for high-throughput cultivation of microorganisms. We have groups onboard that develop hardware. Some participants were invited because of their expertise in metagenomics. And bioinformatics because this knowledge is thought to be crucial to design the right culture conditions to aim at promising microorganisms or environments. NIOZ will use these techniques to isolate the key microorganisms from microbial mats and from marine plankton.

We have also experts on cell-to-cell communication. We aim at using these signal compounds to improve growth and isolation rates. These are several small and medium size companies and one industry partner in the consortium that are interested in applying our expected results and products. These consortium members are working with partners that screen new isolates and existing strains for application.

Finally, we have one professional culture collection on board. Together with numerous specialized culture collections available in the consortium, we will store the newly isolated microorganisms and make them available for the scientific community and for industry. NIOZ maintains a culture collection of marine cyanobacteria and microalgae.

As you can see, this is a large consortium. The aims and the products of this project are chosen in such a way that they can only be achieved by the joint action of several members of the consortium. At NIOZ the Departments of Marine Microbiology and of Biological Oceanography participate in the project. The work is concentrated in dedicated work packages that comprise well-defined tasks for which, in many cases, more than one consortium member is responsible. The collaboration will be further enhanced through frequent meetings between partners and the exchange of personnel.

From: MaCuMBA project news, issue 1

Photo's:
Professor Lucas Stal
Pediastrum
Phormidium
Spirulina