thermotolerant

Thermotolerant describes the ability of an organism, cell, enzyme, or material to withstand, survive, or remain functional at elevated temperatures that would be inhibitory or lethal to typical counterparts. In microbiology, thermotolerant bacteria and yeasts can grow at temperatures ranging from 40 °C to 60 °C, a range that distinguishes them from strictly mesophilic species but falls below the optimal growth temperatures of true thermophiles (> 70 °C). Common thermotolerant microbes include certain strains of *Escherichia coli*, *Saccharomyces cerevisiae*, and *Lactobacillus* spp., which are exploited in food processing, biofuel production, and bioremediation where higher temperatures improve reaction rates and reduce contamination risk.

In plant biology, thermotolerance refers to the capacity of crops and wild species to maintain photosynthetic activity, reproductive development, and cellular integrity during heat stress. Mechanisms involve heat‑shock protein synthesis, membrane lipid remodeling, and activation of antioxidant pathways. Breeding and genetic engineering aim to enhance thermotolerance to mitigate yield losses under climate change scenarios.

Industrial applications leverage thermotolerant enzymes, such as amylases, proteases, and cellulases, that retain activity at temperatures of 50 °C–70 °C, enabling more efficient catalysis, reduced cooling costs, and lower risk of microbial spoilage. These enzymes are often sourced from thermotolerant microorganisms or engineered to improve stability.

Thermotolerance is quantified through growth rate measurements, survival assays, or activity retention under controlled temperature regimes. Understanding the genetic and biochemical bases of thermotolerance informs strategies for developing resilient crops, robust bioprocesses, and durable biomaterials in a warming world.