Thermobiology

Notwithstanding widespread studies and even several biological journals devoted to temperature, it is difficult to perceive a field of thermobiology as such. Interest in the effects of temperature of biological systems is fragmented into specific thermal ranges and often connected with particular applications: subzero cryobiology and preservation of cells and tissues or survival of poikilotherms, para-zero cryobiology and preservation of whole organs and survival of whole animals, intermediate ranges and physiological adaption and regulation, high temperatures and use of heat for killing cancer cells, very high temperatures and limits of biological structure. Yet it has not always been so, and there are good reasons why it need not remain so. General and comparative physiologists such as W.J. Crozier, H. Precht, J. Belehradek, F. Johnson, C.L. Prosser, and others have sought throughout this century to lay foundations for unified approaches to temperature in biological systems.Recent findings also serve to suggest principles and processes that span the range of temperatures of biological interest. Microviscosity of membranes is an issue originally of interest to low temperature biologists but with relevance to limiting high temperatures; conversely for protein structure. Certain "heat shock proteins" now appear to be responses to generalized stress, including low temperature.Inevitably, the chapters of this book reflect the "zonal" character of thermobiology: two chapters (by Storey and Raymond) deal with protection against subfreezing temperatures; three (Hazel, membrane structure, Dietrich, microtubular structure, and Kruuv, cell growth) deal with the effects of and modulation to cool-to-moderate superfreezing temperatures, one (Willis) with modulation (of membrane ion transport) to moderate-to-high temperatures and two (Li, heat shock proteins and Lepock, proteins in general) with stressfully high temperatures. Explicit in each of these chapters, however, are principles and issues that transcend the parochialism of the temperature range under consideration.

Effects of temperature on the state of water in the living cell; Heat effects on proteins and enzymes; Effects of elevated temperatures on DNA and on some polynucleotides: denaturation, renaturation and cleavage of glycosidic and phosphate ester bonds; The effect of heat on membranes and membrane constituents; Temperature effects on micro-organisms; The effect of temperature on the relation between animal viruses and their hosts; Heat responses of higher plants; Insects and temperature; The heat responses of invertebrates (exclusive of insects); Responses of vertebrate poikilotherms to temperature; Resistance to cold in mammals; Resistance to heat in man and other homeothermic animals; Medical applications of thermobiology; Thermal energy as a factor in the biology of soils; Thermal energy as a factor in the biology of the polar regions.

Effects of temperature on the state of water in the living cell; Heat effects on proteins and enzymes; Effects of elevated temperatures on DNA and on some polynucleotides: denaturation, renaturation and cleavage of glycosidic and phosphate ester bonds; The effect of heat on membranes and membrane constituents; Temperature effects on micro-organisms; The effect of temperature on the relation between animal viruses and their hosts; Heat responses of higher plants; Insects and temperature; The heat responses of invertebrates (exclusive of insects); Responses of vertebrate poikilotherms to temperature; Resistance to cold in mammals; Resistance to heat in man and other homeothermic animals; Medical applications of thermobiology; Thermal energy as a factor in the biology of soils; Thermal energy as a factor in the biology of the polar regions.

As a result of developments in biotechnology, bioengineering, and related sciences, processing of bio-materials and bioproducts has become an area of strategic importance. Written in a textbook style, this book attempts to bring together both the theory and practice of thermal processing of bio-materials. After giving the basic information on material properties, the authors describe the principal techniques such as freezing, chilling, membrane concentration, evaporation, drying, and sterilization. New methods of drying based on the authors' research experiences are presented to a great extent. Much attention is paid to quality interactions, including degradation of thermo and xerolabile bio- products. Given the strong effect of temperature on micro-organisms, a separate chapter is dedicated to thermobacteriology.