Introducing Steve Pointing

by Steve Pointing

I am extremely happy to announce that I will be taking up a new position as Assistant Professor in DEB from September 2001. Some of you already know me and are familiar with my research and teaching - you can skip this page! This article is really intended to introduce myself to any staff, students and affiliates of DEB who do not know me yet.

My first inspiration to become a biologist came from following the heavily accented adventures of Jacques Yves Cousteau on TV as a kid. I read The Silent World, learned to SCUBA dive and thought of becoming a marine biologist. I was, however; lured to what many might consider ‘the dark side’ as an undergraduate - I became fascinated by enzymology, and finally graduated with a major in biochemistry!

As a postgraduate, I found that microorganisms had the most interesting biochemistry, and that working on them had the added bonus of not requiring me to kill any ‘real’ animals. Ultimately I managed to include a bit of everything biological that I loved into my PhD – the marine environment, enzymology and microorganisms!

My current research interests are varied, although they all adhere to a common theme of microbial ecophysiology - the study of physiological adaptations of organisms to habitat or environment. I am particularly interested in the catabolism of lignin in aquatic environments. Lignin is the Earth’s second-most abundant biological polymer with annual production estimated at over 20 x 10¹² kg. It is the component of wood and grasses that confers decay resistance, so it is extremely difficult to break down. This abundance and resistance to decay make lignin breakdown a rate-limiting step to carbon cycling within many environments. My PhD student, Ms Vivienne Bucher, is currently researching the relative lignin-degrading ability of freshwater and marine microorganisms at the molecular and physiological level. I also have a project in collaboration with the Department of Biochemistry at HKU investigating transcriptional control of the enzymes involved in this process in response to nutrient and pollution stress. One fortuitous spin-off from these studies has been the discovery that the enzymes involved are highly non-specific – that is they can degrade a number of compounds with chemical structures similar to lignin, and these include priority-listed organic pollutants such as PCB and PAH. Another of my postgraduate students, Ms Sin Kai Wai, is currently researching the possibility of using lignin-degrading microorganisms in pollution control.

Fig.1 Structural similarities between a lignin monomer (coumarly alcohol), a PAH (phenanthrene) and a PCB (tetrachlorobiphenyl)

I have also been developing an interest in the ecophysiology of extremophiles, which are organisms living under particular stresses of water, chemical and/or energy source availability. I am particularly interested in microorganisms capable of living in volcanically influenced habitats. I have visited the volcanoes, sulphur-mats, hot-springs and solfatara of the Phillippines and Hawaii over the last year and intend to begin a research programme in this field during 2002.

I am an experienced teacher, having taught at undergraduate level for 5 years. I hope to draw upon my research interests to introduce new and interesting topics to my teaching at DEB that will appeal to students. I am particularly keen to include molecular and physiological aspects of microbial ecology, with particular reference to environmental stress. Any of you interested in reading more about my interests may want to check out: S.B. Pointing (2001) Exploiting the Versatile Ligninolytic System of White-rot Fungi, In: Bio-Exploitation of Filamentous Fungi (ISBN 962-85677-2-1) and J. Postgate (1996) The Outer Reaches of Life (ISBN 0-521-55873-5).

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