Chitin Aims and Scope Topics in Geobiology Book Series Topics in Geobiology series treats geobiology – the broad discipline that covers the history of life on Earth. The series aims for high quality, scholarly volumes of original research as well as broad reviews. Recent volumes have showcased a v ariety of organisms including cephalopods, corals, and rodents. They discuss the biology of these organisms-their ecology, phylogeny, and mode of life – and in addition, their fossil record – their distribution in time and space. Other volumes are more theme based such as predator-prey relationships, skeletal mineralization, paleobiogeography, and approaches to high resolution stratigraphy, that cover a broad range of organisms. One theme that is at the heart of the series is the interplay between the history of life and the changing environment. This is treated in skeletal mineralization and how such skeletons record environmental signals and animal-sediment relationships in the marine environment. The series editors also welcome any comments or suggestions for future volumes. Series Editors Neil H. Landman, Chitin Formation and Diagenesis Neal S. Gupta Editor Editor Neal S. Gupta Indian Institute of Science Education and Research Mohali, India Preface There are several books on properties of chitin and associated biomolecules and their biochemical significance. However, the present volume, ‘Chitin: Formation and Diagenesis’ deals with a wide variety of biogeochemical and organic geo- chemical aspects of this vital macromolecule written by leading authors and experts in the field. Chapter 1 deals with chitin nanostructures in living organisms and observes that the occurrence of a chitin-producing system is an ancestral condition present in a number of phyla that supported many organisms during the Cambrian explosion. Current research in the chapter states that chitinous nanostructures are important in order to understand the roles of chitin in vivo, as well as to prepare materials for medical and veterinary applications. Chapter 2 focuses on chitin in the exoskeletons of arthropods. Arthropods use chitin and various proteins as basic materials of their cuticle which form the exoskeletons. The exoskeleton is composed of skeletal ele- ments with physical properties that are adapted to their function and the eco-phys- iological strains of the animal. These properties are achieved by forming elaborate microstructures that are organized in several hierarchical levels. Additionally, the properties are influenced by variations in the chemical composition of the cuticle, for instance by combining the organic material with inorganic nano-particles. Thus, there is an emphasis in the chapter right from ancient design to novel material science. Chapter 3 covers recent advances in pretreatment chemistry for AMS radiocarbon dating of insects, including isolation of polymeric chitin or chitin monomers. The uses of chitin dates, in particular the archaeological and palaeoen- vironmental applications, are also discussed. Problems with the radiocarbon dating of insects, including contamination, degradation, and the often observed offset between dates of insect remains and surrounding organic material, are addressed along with potential solutions. Chapter 4 discusses that stable isotope ratios in chi- tin are firmly imprinted during biopolymer biosynthesis and reflect dietary, meta- bolic, and environmental influences. Additionally, chemically preserved archeological chitin are isotopically compatible with modern chitin from compa- rable environments and new analytical stable isotope techniques with reduced sample size requirements open opportunities to utilize geologically preserved chitin in paleoenvironmental studies. Chapter 5 provides data that show intra- and inter- specimen D/H variation in modern water beetles that may relate to systematic v vi Preface variations in chitin biosynthesis during exoskeleton development. A discussion of existing hydrogen-isotope studies of chitin are presented, including recent advances in hydrogen-isotope analysis that can enhance sample throughput. Chapter 6 pro- vides data on mass spectral investigation of chitin using pyrolysis–GC–MS and 13 characteristic peaks using solid state C NMR and scanning transmission x-ray microscopy (STXM) coupled to C,N,O-XANES to facilitate identification of com- pounds and characteristic peaks for future studies. In Chapter 7 analysis of fossils using a range of mass spectrometric and spectroscopic methods have shown that preserved cuticles include significant amounts of aliphatic hydrocarbon component at times with an aromatic component that is very different to the composition of the cuticle of the living arthropod. Analysis of successively older fossil material reveals that this transformation to an aliphatic composition is gradual and perhaps time dependant. Taphonomic incubation experiments demonstrate that lipids such as fatty acids are incorporated into the decaying chitin protein exoskeleton as early as a few weeks contributing to the aliphatic component. This is supported by chemo- lytic analysis of fossils that reveal presence of fatty acyl moieties in the macromol- ecule. Chapter 8 introduces a unique hydrothermal experimental study by comparison of the products derived from maturation of different pre-treated plant and arthropod tissues demonstrates that solvent-extractable and hydrolysable lipids are precursors of the generated aliphatic macromolecular material. Thus, the experiments indicate that labile alkyl compounds can be a source of the insoluble aliphatic component of fossil organic matter in the absence of a resistant aliphatic precursor in the living organism. Mohali, India Neal S. Gupta Acknowledgements Even though I had the privilege and fortune to edit this volume on biogeochemical significance of chitin, several people need to be thanked, as without them it would have been impossible to assemble this. Each chapter has been carefully peer reviewed and I am grateful to the following people for it: Dr. Jennifer A. Tripp (University of Scranton), Dr. Shuhei Ono (MIT), Dr. Darren Gröcke (University of Durham), Dr. Weifu Guo (Carnegie Institution of Washington), Dr. Alok K. Gupta (University of Allahabad), Professor Roger Summons (MIT). Professor Derek Briggs (Yale University) is thanked for discussions regarding outlining the chapters and content of the volume. Dr. Neil Landman is thanked for useful comments from time to time and for correspondence in tracking the progress of the volume. Mrs. Judith Terpos is thanked for guiding me in the production of the volume. I also thank the host universities where I worked in order to compile the volume. They are Yale University, New Haven, CT, USA, MIT, Cambridge, MA, USA and the Carnegie Institution of Washington, Washington D.C., USA. I thank my father Professor Alok K. Gupta for the motivation to complete it in time and my wife Mrs. Mary Gupta for being very patient during the entire process. Mohali, India Neal S. Gupta vii Contents 1 Chitin Nanostructures in Living Organisms .......................................... 1 Riccardo A.A. Muzzarelli 2 Chitin in the Exoskeletons of Arthropoda: From Ancient Design to Novel Materials Science............................................. 35 H. Fabritius, C. Sachs, D. Raabe, S. Nikolov, M. Friák, and J. Neugebauer 3 Radiocarbon Dating of Chitin.................................................................. 61 Jennifer A. Tripp and Thomas F.G. Higham 4 Carbon, Nitrogen and Oxygen Stable Isotope Ratios in Chitin ........... 81 Arndt Schimmelmann 5 Hydrogen Isotopes in Beetle Chitin ......................................................... 105 Darren R. Gröcke, Maarten van Hardenbroek, Peter E. Sauer, and Scott A. Elias 6 Identifcation and Characterization of Chitin in Organisms ................ 117 Neal S. Gupta and George D. Cody 7 Fate of Chitinous Organisms in the Geosphere ...................................... 133 Neal S. Gupta and Roger E. Summons 8 Transformation of Chitinous Tissues in Elevated Presssure–Temperature Conditions: Additional Insights from Experiments on Plant Tissues ......................................................... 153 Neal S. Gupta Index ................................................................................................................. 169 ix