15 October 2012 Cryoprotection from lipoteichoic acid
Author Affiliations +
Abstract
Numerous chemical additives lower the freezing point of water, but life at sub-zero temperatures is sustained by a limited number of biological cryoprotectants. Antifreeze proteins in fish, plants, and insects provide protection to a few degrees below freezing. Microbes have been found to survive at even lower temperatures, and with a few exceptions, antifreeze proteins are missing. Survival has been attributed to external factors, such as the high salt concentration of brine veins and adhesion to particulates or ice crystal defects. We have discovered an endogenous cryoprotectant in the cell wall of bacteria, lipoteichoic acid biopolymers. Adding 1% LTA to bacteria cultures immediately prior to freezing provides 50% survival rate, similar to the results obtained with 1% glycerol. In the absence of an additive, bacterial survival is negligible as measured with the resazurin cell viability assay. The mode of action for LTA cryoprotection is unknown. With a molecular weight of 3-5 kDa, it is unlikely to enter the cell cytoplasm. Our observations suggest that teichoic acids could provide a shell of liquid water around biofilms and planktonic bacteria, removing the need for brine veins to prevent bacterial freezing.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Charles V. Rice, Charles V. Rice, Amy Middaugh, Amy Middaugh, Jason R. Wickham, Jason R. Wickham, Anthony Friedline, Anthony Friedline, Kieth J. Thomas, Kieth J. Thomas, Karen Johnson, Karen Johnson, Malcolm Zachariah, Malcolm Zachariah, Ravindranth Garimella, Ravindranth Garimella, } "Cryoprotection from lipoteichoic acid", Proc. SPIE 8521, Instruments, Methods, and Missions for Astrobiology XV, 85210I (15 October 2012); doi: 10.1117/12.970517; https://doi.org/10.1117/12.970517
PROCEEDINGS
9 PAGES


SHARE
Back to Top