The Secret Chemistry and Biology of the Sulfur Cycle
Title: The Secret Chemistry and Biology of the Sulfur Cycle
Speaker: Prof Spencer Williams, the University of Melbourne
Abstract: The biogeochemical sulfur cycle describes how sulfur transits through the mineral, atmospheric, hydrologic and biological compartments of our planet. Within the biological domain an estimated 10 billion tonnes of the sulfosugar sulfoquinovose (SQ) are formed annually, an amount commensurate with the amino acids cysteine and methionine. SQ is a significant biosulfur reservoir within photosynthetic tissues, and is broken down through the microbial pathways of sulfoglycolysis and sulfolysis. My group studies the chemistry, biochemistry, microbiology, and structural biology of SQ breakdown. In this talk I will describe the discovery of specialized glycosidases termed sulfoquinovosidases that release SQ from sulfolipids, a new pathway for SQ degradation that achieves the cleavage of the distinctive carbon-sulfur bond, and the development of synthetic tools that can be used to study and exploit the new enzymes and proteins that we have discovered. New knowledge of these pathways provides insights into the biogeochemical sulfur cycle and microbial ecology in our seas and soils.
Bio: Spencer Williams is a Professor of Chemistry at the University of Melbourne (2002-present). He received his PhD at the University of Western Australia (1998). He undertook postdoctoral training with Professor Stephen G Withers at the University of British Columbia, Canada (1998-2000), and with Professor Carolyn Bertozzi at the University of California, Berkeley (2001-2002). His research interests include carbohydrate chemistry and biochemistry; metabolic pathways for organosulfur metabolic currencies, and medicinal chemistry. He has authored over 200 journal articles and 13 patents, and a textbook, Carbohydrates: The Essential Molecules of Life. He is co-founder of several startup companies including Fibrotech, Certa, OccuRx and TianLi. He is the recipient of the Royal Society of Chemistry Horizon Prize for Chemical Biology (2024).
About Bertram Dillon Steele Lecture
![Bertram Dillon Steele](/files/1567/steele.jpg)
The Bertram Dillon Steele Lecture commemorates UQ’s founding Professor of Chemistry, Bertram Dillon Steele, one of the original four professors appointed to the University.
Professor Steele was also the first president of the University’s Professorial Board (now known as the Academic Board) and chaired the Royal Commission on Prickly Pear, once an environmental scourge in Queensland.
The lecture was founded in 1982 by the UQ Chemical Society within the then Department of Chemistry.
The lecture was not offered in 2020 and 2021 due to the COVID-19 pandemic. From 2022 it is offered every second year, alternating with the School's other chemistry public lecture, the T. G. H. Jones Memorial Lecture.
Read more about Professor Steele on our history page.