Chapter 6
When the Vital Signs of Microbial Life Go
Cold, Does That Mean the Pulse Is Gone?
Microbial Life Persists at the Limits
of Cryoenvironments on Earth
Jacqueline Marie Goordial
Abstract Cryoenvironments on Earth represent a natural laboratory in which we
can observe the natural constraints to microbial activity and survival at low temperature. Microorganisms in sub-zero environments must contend with numerous
stressors, and though microorganisms are nearly ubiquitous on this planet, the
question of their activity under extremes of temperature is an open one. This essay
describes soils in University Valley, located in the McMurdo Dry Valleys of
Antarctica—a rare site in which microbial activity cannot be measured. Though
the signs of active life were absent, the region is by no means dead. Microbial life
persists in this valley, as in other cryoenvironments, and potentially on other
planetary bodies within our solar system.
6.1 Introduction: Microorganisms Are the Foundation
of Ecosystem Function in Cryoenvironments
What are the limits of microbial life? What are the most extreme conditions
(temperature, pH, pressure nutrient deprivation, etc.) that a microorganism can survive in? And what is the difference between merely surviving and thriving? These
questions have fascinated scientists for many years, ranging in fields from biology to
planetary science. This essay will focus on the nature of life at extremes of cold
temperature, in cryoenvironments. Cryoenvironments are generally defined as environments that exist either continuously or predominately at sub-zero temperatures.
They occur in polar and alpine regions and include visually stunning large-scale
features such as glaciers, sea ice, permanently ice-covered lakes and permafrost.
Studies from both cryoenvironments and laboratories on Earth have demonstrated
that microbial life is widespread in cold environments, can be metabolically active,
J. M. Goordial (*)
University of Guelph, Guelph, ON, Canada
e-mail: goordial@uoguelph.ca
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_6
115
When the Vital Signs of Microbial Life Go
Cold, Does That Mean the Pulse Is Gone?
Microbial Life Persists at the Limits
of Cryoenvironments on Earth
Jacqueline Marie Goordial
Abstract Cryoenvironments on Earth represent a natural laboratory in which we
can observe the natural constraints to microbial activity and survival at low temperature. Microorganisms in sub-zero environments must contend with numerous
stressors, and though microorganisms are nearly ubiquitous on this planet, the
question of their activity under extremes of temperature is an open one. This essay
describes soils in University Valley, located in the McMurdo Dry Valleys of
Antarctica—a rare site in which microbial activity cannot be measured. Though
the signs of active life were absent, the region is by no means dead. Microbial life
persists in this valley, as in other cryoenvironments, and potentially on other
planetary bodies within our solar system.
6.1 Introduction: Microorganisms Are the Foundation
of Ecosystem Function in Cryoenvironments
What are the limits of microbial life? What are the most extreme conditions
(temperature, pH, pressure nutrient deprivation, etc.) that a microorganism can survive in? And what is the difference between merely surviving and thriving? These
questions have fascinated scientists for many years, ranging in fields from biology to
planetary science. This essay will focus on the nature of life at extremes of cold
temperature, in cryoenvironments. Cryoenvironments are generally defined as environments that exist either continuously or predominately at sub-zero temperatures.
They occur in polar and alpine regions and include visually stunning large-scale
features such as glaciers, sea ice, permanently ice-covered lakes and permafrost.
Studies from both cryoenvironments and laboratories on Earth have demonstrated
that microbial life is widespread in cold environments, can be metabolically active,
J. M. Goordial (*)
University of Guelph, Guelph, ON, Canada
e-mail: goordial@uoguelph.ca
© Springer Nature Switzerland AG 2021
C. J. Hurst (ed.), Microbes: The Foundation Stone of the Biosphere, Advances in
Environmental Microbiology 8, https://doi.org/10.1007/978-3-030-63512-1_6
115