Meet the 2022 Marjory Stephenson Prize Winner, Professor Geoffrey Gadd

07 April 2022

Geoffrey M Gadd Marjory Stephenson Prize 2022 credit GM Gadd_ccexpress.jpeg

The Marjory Stephenson Prize is the principal prize of the Microbiology Society, awarded for an outstanding contribution of current importance in microbiology. 
Ahead of the Marjory Stephenson Lecture, Paz Aranega, ECM Forum Executive Committee Member, interviewed Professor Geoffrey Gadd to learn more about his career and how it feels to win a Microbiology Society prize.

For those of us that do not know a lot about geomicrobiology, can you briefly describe this field of research?

Geomicrobiology encompasses almost everything about microbiology and the environment and, in a general sense, refers to current and past activities of micro-organisms in environmental transformations that are related to geology. Such activities include cycling of elements, rock and mineral dissolution, mineral formation, soil formation and development. Geomicrobiology also includes what microbes have done in the past, which of course has led to the development and evolution of the biosphere, major changes in the Earth’s surface and the deposition of certain minerals. Transformations of organic and inorganic substances, e.g. rocks and minerals, are of key importance. Some geomicrobial activities can affect us negatively in areas like biodeterioration in the built environment but, in a beneficial sense, decomposition of organic pollutants and immobilisation or transformation of metals and radionuclides can be used in bioremediation. These processes are also relevant to metal bioleaching, biomining and biorecovery, and the development of new biometal and biomineral products, including those at the nanoscale. Several commercial bioleaching and bioremediation processes have been in operation for many years now. Without geomicrobiological processes, carried out by members of all the major groups of micro-organisms, the planet would not function because these activities influence ecosystem health and function, plant productivity and therefore human health.

You work in basic and also more applied research, what do you enjoy the most?

I have worked for a long time with microbial systems and there has always been a connection with the environment and environmental processes. Fungi have been the main experimental organisms, with other work on sulfate-reducing bacteria, cyanobacteria and microalgae. Several years ago, we realised that some of the processes by which organisms can change the chemical speciation of metals can be applied to pollution treatment and metal recovery so we had various industrial contracts as well as research grants exploring the fundamental scientific mechanisms behind metal—microbe interactions. Subsequently, I got more interested in how micro-organisms can make minerals, because this is an effective way to immobilise a metal, and it turned out that biomineralisation is widespread in the microbial world, with fungi rather neglected in this area. One reason why I am particularly interested in this is that many biominerals are crystalline and very beautiful, having different shapes, sizes and colours, which is aesthetically pleasing as well as interesting scientifically. We then found that many of the biominerals that are deposited are in the nanoscale size range which stimulated an interest in the properties of such nanoparticles and nanobiotechnology in recent years. It is always appealing to see the beautiful images of the crystals and nanoparticles obtained by my gifted research group.

What are you going to be talking about in your presentation?

The main focus of the lecture will be fungal biomineralisation. As fungi have a much simpler metabolism compared to prokaryotes, especially those inhabiting the subsurface, they have been underappreciated in terms of geochemical transformations. However, this has changed rapidly and we now know they have incredible importance in the biosphere and wherever you find fungi there are transformations of organics, metals and minerals and where these transformations occur biomineralization is an important feature. In the presentation, I will discuss the significance of fungal biomineralization in natural and synthetic environments, such as the built environment including cultural heritage (e.g. monuments and statues), and applications in bioremediation and biorecovery of valuable elements. I will also include fungal-produced nanozymes, which are inorganic materials with activities similar to enzymes, and their significance for the organism and the environment.

Do you have a favourite micro-organism?

I enjoy many micro-organisms, particularly those that make bright colours. When I was a student there were many puns about certain micro-organisms. Bacillus cereus was one which led to “Do B. cereus” being a common retort while Sue de Monas was a common signature on graffiti.   However, the organism that started me off and was fundamental to my career was Aureobasidium pullulans, which I isolated from toxic metal-loaded enrichment cultures during my PhD and thought I had discovered a new organism. Not so, it is everywhere in the environment, ubiquitous on and in plant leaves and surfaces, and is the most important spoilage organism of painted surfaces. Many of you will have it as black growth in your bathroom or toilet. It also produces a polysaccharide (pullulan) that is used industrially. This organism rescued my PhD, as it stimulated my interest in fungi growth and metal responses, the subject of my first few papers and my first research grant. Aspergillus niger, which is used industrially to make citric acid, is a more recent favourite because it can mediate very interesting metal and mineral transformations and has been the subject of many of our papers in recent years.

What would you say are the pros and cons of working in research?

In research you always have ups and downs, successes and failures, particularly earlier in your career when a rejected grant application can seem devastating!  The ultimate pro is that you are free to pursue any particular problem or phenomenon that you are interested in, providing you can get funding to support the work. I have been very lucky in that I have been able to support research I have been very interested in throughout my career, in a way that has given me the freedom to go in whatever direction I choose. PhD student projects are particularly valuable and some of our most original and best work has come from gifted PhD students on projects that are not highly prescriptive and allow change and pursuit of new directions. Another big pro is that the research can take you all over the world. I have been to fantastic places in many countries and have really good friends all over the world thanks to research.  For cons, the constant pursuit of funding, and the accompanying pressure by employers to obtain funding. Also, there is now too much teaching and research administration (and administrators) which can be inhibitory to research activity.

You have chosen to stay in the UK for your career, do you regret not having taken a position abroad?

I often think about this because, before I got my first position, I got offered a postdoc at the Rockefeller Institute in New York, US, where I think there were two Nobel Prize winners among the staff. I was also awarded a postdoc at University College Dublin, Ireland. However, I went to Dundee. I have had later offers in the UK and overseas, but I stayed loyal to my institution and have no regrets about not going abroad. I travel a lot anyway and have many international collaborations.

Do you think it is important to communicate your research to non-expert audiences?

Yes, I do. Some science is not straightforward to explain but my research is very easy because people can relate to it, and everyone wants a clean safe environment. For example, I work with microbes that can destroy or treat pollutants. I have had many good experiences explaining what I do to friends, general audiences, students and school children here and overseas.  It is important that scientists and experts communicate clearly and loudly, especially in view of the current torrents of fake news and misinformation.

You have authored more than 300 publications during your research career. Early career researchers often struggle to choose an appropriate journal to publish, having to balance many aspects such as ethics, potential visibility for the work and impact to secure jobs and funding. Do you have any advice?

When I was starting off, life seemed a bit simpler. You were a member of microbiology societies and you published in society journals. So, for example, I was a member of the SGM (Society for General Microbiology; now Microbiology Society) and tried to publish in the Journal of General Microbiology. Similarly, I published in journals of the British Mycological Society and in FEMS journals. You felt like these were proper journals, read by everyone, and that at least some of the income went back to the society and scientists. Before impact factors, you picked a journal based on its reputation for quality or a perceived high profile. Now, we have to put up with impact factors, citation indices, tweets and the like, and they might be important sometimes but not always. Many journals have artificially inflated IFs. There are many journals now that are just commercial enterprises and the income they make goes to the publishers and shareholders and nothing comes back to the science. Some predatory publishers are purely exploitative. So carefully look at journals and publishers, read articles about them, support societies if you can and ask advice from your more experienced older research-active colleagues. The main thing is to carry out research of high quality and quality publications will follow.

Marjory Stephenson was one of the first two women elected as a Fellow of the Royal Society, shortly after women started to be accepted as fellows. Many years later we still struggle with discrimination in science fields. What do you do to support diversity and inclusion in the microbiology community?

My career has always been international. I am an internationalist, I have many friends worldwide, and my research group has always been international which I believe is essential. I have mentored three women within microbiology (and other early career researchers) in an official capacity who have thrived and are now in senior positions in the UK, USA and Thailand respectively. Through my friendship with the late Nuzhat Ahmed, Head of Microbiology and Biotechnology at Karachi University, Pakistan, I had a succession of gifted women, PhD students from Pakistan, in my lab who have all been successful in securing permanent jobs in academia back home or elsewhere. I was able to provide an unrestricted environment where they could pursue their own ideas and I am very proud of that. Personal relationships are very important in scientific collaboration, to collaborate properly there needs to be trust and friendship.

How has being a member of the Microbiology Society supported your career?

I joined the Microbiology Society, then known as the Society for General Microbiology, during my PhD and have been involved with it in one way or another for most of my career and served on several committees and organised several conferences.  The Society had a small grant scheme where you had to write a short application and if successful you received a small amount of money (around £2000) to support your research. Most of my research is quite economical and these grants were extremely helpful. I have also spoken at many Society meetings over the years.

Image: GM Gadd.