Environmental Stress Responses of Lactic Acid Bacteria

Abstract

Lactic acid bacteria (LAB) are often used to produce fermented foods. LAB usually grow in “moderate” environmental conditions and commonly encounter stress conditions like changes in pH, temperature, production, storage, and others (Kim NR, Jeong DW, Ko DS, Shim JH, Intl J Biol Macromol 99:594–599. https://doi.org/10.1016/j.ijbiomac.2017.03.009, 1997). These condition changes may lead to poor growth rate or even survival of the bacteria. Stress responses were of great importance for microorganism; they always continually change with temperature and osmotic pressure in the environments (Becker MR, Paster BJ, Leys EJ, Moeschberger ML, Kenyon SG, Galvin JL, Boches SK, Dewhirst FE, Griffen AL, J Clin Microbiol 40(3):1001–1009. https://doi.org/10.1128/jcm.40.3.1001-1009.2002, 2002). There are various kinds of stress factors, which include physical, chemical, or biological and others. LABs are exposed to these stresses during fermentation, for example, low temperature, high H₂O_2, and low pH (Kurz M, Saline Syst 4:6. https://doi.org/10.1186/1746-1448-4-6, 2008; Burokas A, Arboleya S, Moloney RD, Peterson VL, Murphy K, Clarke G, Stanton C, Dinan TG, Cryan JF, Biol Psychiat 82:472. https://doi.org/10.1016/j.biopsych.2016.12.031, 2017; Becker MR, Paster BJ, Leys EJ, Moeschberger ML, Kenyon SG, Galvin JL, Boches SK, Dewhirst FE, Griffen AL, J Clin Microbiol 40(3):1001–1009. https://doi.org/10.1128/jcm.40.3.1001-1009.2002, 2002). LABs have the stress-sensing systems to activate defenses, permitting the bacteria to acclimatize the harsh conditions or environmental changes. In LAB, DNA-repairing mechanisms can be also characterized as responding to oxidative stress and acid stress.