Abstract

There is increasing recognition of the need to reduce our reliance on fossil carbon for fuels and materials, whilst at the same time mitigating the consequences of the waste generated as a result of domestic, agricultural and industrial activities. Plants and algae, as photosynthetic organisms, offer considerable potential as means to generate everything from bulk feedstocks to platform chemicals and high value products, using solar energy as the main input. Microalgae in particular are an underexploited resource for sustainable production of a range of novel products. In addition, incorporation of microalgal cultivation into different processes in a modular fashion enables valorisation of waste streams – a concept that we have termed Circular Photosynthesis. I will discuss the reasons why microalgae are a rich source of vitamin B12 , an essential organic micronutrient synthesised only by bacteria, and how it is possible for algae to obtain B12 in mutualistic co-culture with bacteria. We are exploiting this in efforts to produce food and feed with enhanced nutritional profiles. In addition, I will illustrate how we have been working with colleagues in developing countries to introduce Circular Photosynthesis approaches so that they can be deployed widely at local scale, supporting innovation and enterprise, and reducing waste.