Marine microbiologist Henk Bolhuis investigates the greenish-brown, slimy layers that cover parts of the beach and the mudflats at low tide. ‘Those are microbial mats. They consist of a wickerwork of algae and bacteria that is sometimes so strong you can even pull it off the floor as a tight mat. Our fundamental research into these microbes has revealed that bacteria play a role in coastal protection. They are currently being investigated for their use in the development of saline agriculture.’
’We investigate cyanobacteria – blue-green algae – and diatoms, which are true algae. These are literally the mini solar panels and food factories of the mudflat and drive a rich community of hundreds of different species of bacteria. During the day, they use energy from sunlight to combine carbon dioxide with water to produce oxygen and sugars for growth and as a food reserve. They run on those sugars at night until the sun comes up again. This results in high biomass of microbes that form a rich food source for other lifeforms, such as shellfish.’
‘The excess sugars are excreted, as a result of which sand grains stick to each other. On the green beach of Schiermonnikoog, for example, you can see the consequences of that: the loose sand is held in place by the microbes, which provides plants with food and firm soil and resulted in a rich salt marsh vegetation. In that sense, microbes may form the basis for dune formation and natural coastal protection. Without these microbial mats, the sand would keep shifting.’
‘My primary interest lies in the fundamental biology of these ecosystems. In fact, we can compare the five millimetres of microbial mats with the complete ocean ecosystem. It contains similar physical features in terms of light and oxygen gradients and a similar food web containing producers, predators and decomposers.’
‘Furthermore, I can really enjoy the beauty of microbes. An example is when filmmaker and photographer Wim van Egmond joins our team to make time-lapses of the undulating movements of microbes in the mudflat. Sooner or later, this type of research will eventually result in practical applications. For example, in the EU project SIMBA, we will investigate over the next few years whether salt-tolerant bacteria in the soil could be key for making future farming more resilient to the intruding salinisation due to sea-level rise.’
Read more +Synthetic Microbial Ecology (Minimal Microbial Mats)
MAIL me for student projects in bioinformatics, extremophiles and marine microbial ecology.
1996 Fellowship from the Human frontier Science Programme Organization (HFSPO) for a post doctoral position at the Max Planck Institute for Biochemistry, Munich, Germany. Project; Structure function analysis of the sensory-rhodopsin I complex from Halobacterium salinarum.
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Students working on coastal microbial mats at Schiermonnikoog, the Netherlands
Haloquadratum walsbyi (Strain HBSQ001) the enigmatic square hyperhalophilic Archaeon
DNA laboratory in Brunei
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