Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 31, 2011
Publication Date: December 1, 2011
Citation: Wells, J., Varel, V.H. 2011. Chapter 9: Symbiosis of plants, animals, and microbes. In: Pond, W. G., Bazer, F. W., Rollin, B. E. (ed). Animal Welfare in Animal Agriculture: Husbandry, Stewardship and Sustainability. New York: CRC Press. p. 185-203. Technical Abstract: A diversity of plants, animals and microbes on Earth abound due to evolution, climate, competition, and symbiosis. Single cell species such as microorganisms are assumed to have evolved initially. Over time, plants and animals established and flourished. As each new kingdom of life came about, the ecosystem on Earth became more complex and the bionic components became more interactive. Symbiosis, in a broad definition is, “the living together in an intimate association of two or more dissimilar organisms.” Symbiosis can result in a relationship in which both organisms benefit. Nitrogen fixation by legumes is a consequence of microbes that fix nitrogen and plants that supply simple carbons. Plants and fungi have established a cooperation in which the plant provides nutrients and the fungi provide alkaloids to deter predation and allow for greater drought tolerance. More generally, plants and herbivores have essentially co-evolved such that the action of herbivores on plants can lead to greater diversity and dispersion of seed. Complex cellulose degradation of plant material by herbivores is accomplished by specialized bacteria in gastrointestinal compartments that are optimally maintained by each host animal for bacterial growth. Within the mammalian digestive tract, commensal microorganisms can provide energy, amino acids, and vitamins for the host, and provide protection against parasitic microorganisms. This chapter focuses on environmental sustainability of the many symbiotic relationships among plants, animals, and microbes that enhance our global food production.