MICROBIOLOGY TERMS AND DEFINITIONS FROM X

X-factor definition

• Substances from the heme fraction of blood hemoglobin. (Microbiology: An Introduction by Tortora, Funke, and Case)

X-ray definition

• The ionizing radiation that can be used to sterilize objects. (Alcamo’s Fundamentals of Microbiology)

Xenobiotic definition

• A synthetic compound not produced by organisms in nature. (Brock Biology of Microorganisms)
• Synthetic chemicals that are not readily degraded by microorganisms. (Microbiology: An Introduction by Tortora, Funke, and Case)

Xenodiagnosis definition

• A method of diagnosis based on exposing a parasite-free normal host to the parasite and then examining the host for parasites. (Microbiology: An Introduction by Tortora, Funke, and Case)

Xenograft definition

• A tissue graft between members of different species, such as between a pig and a human. (Alcamo’s Fundamentals of Microbiology)
• The transfer of a tissue or an organ from an animal of one species to a recipient of another species. (Foundation in Microbiology by Talaro and Chess)
• A tissue graft from another species. (Microbiology: An Introduction by Tortora, Funke, and Case)
• A tissue graft between animals of different species. (Prescott’s Microbiology)

Xerophile definition

• An organism adapted to growth at very low water potentials. (Brock Biology of Microorganisms)
• Microorganisms that grow best under low water activity (aw) conditions, and may not be able to grow at high aw values. (Prescott’s Microbiology)