Catalase Activity as a Biomarker for Mild-Stress-Induced Robustness in Bacillus weihenstephanensis

Abstract

Microorganisms are able to survive and grow in changing environments by activating stress adaptation mechanisms which may enhance bacterial robustness. Stress-induced enhanced robustness complicates the predictability of microbial inactivation. Using psychrotolerant Bacillus weihenstephanensis strain KBAB4 as a model, we investigated the impact of the culturing temperature on mild-oxidative-stress-induced (cross-)protection toward multiple stresses, including severe oxidative, heat, and acid stresses. Culturing at a refrigeration temperature (7°C) compared to the optimal growth temperature (30°C) affected both the robustness level of B. weihenstephanensis and the oxidative stress adaptive response. Scavengers of reactive oxygen species have a crucial role in adaptation to oxidative stresses, and this points to a possible predictive role in mild-oxidative-stress-induced robustness. Therefore, the catalase activity was determined upon mild oxidative stress treatment and was demonstrated to be significantly correlated with the robustness level of mild-stress-treated cells toward severe oxidative and heat stresses but not toward severe acid stress for cells grown at both refrigeration and optimal temperatures. The quantified correlations supported the predictive quality of catalase activity as a biomarker and also underlined that the predictive quality is stress specific. Biomarkers that are able to predict stress-induced enhanced robustness can be used to better understand stress adaptation mechanisms and might allow the design of effective combinations of hurdles to control microbial behavior.

Influence of Aeration Speed on Bacterial Colony Forming Unit (CFU) Formation Capacity

“…The comparative resistance might be due to the unique cellular survival mechanism imparted by Bacillus spp. [39,40,41,42,43].…”

Study of exogenous oxidative stress response in Escherichia coli, Pseudomonas spp., Bacillus spp., and Salmonella spp.

“…based on the available information about their survival mechanisms has yet to be undertaken (Christman et al, 1985;Inaoka et al, 1990;Farr and Kogoma, 1991;Givskov et al, 1994;Nitta et al, 2000;Sabra et al, 2002;Kabir et al, 2004;Passalacqua et al, 2006Passalacqua et al, , 2007Den Besten et al, 2009;Noor et al, 2009aNoor et al, , 2009bZuber, 2009;Pohl et al, 2011;Huillet et al, 2012;Murata et al, 2012;Den Besten et al, 2013;Nagamitsu et al, 2013). In relation to current studies on bacterial oxidative stress responses, the present study employed preliminary experiments to resolve the impact of increased concentration of the oxidant.…”

“…Stress responses among microbial populations against an array of environmental physicochemical stimuli including temperature, irradiation, pH, osmolyte/salt concentration, reactive oxygen species (ROS), redox state, toxic compounds, and nutrient depletion are well known (Türkel, 2000;Den Besten et al, 2009;Ju and Parales, 2010;Fuchs et al, 2011;Kivisaar, 2011;Parry et al, 2011;Deepika et al, 2012;Den Besten et al, 2013;Noor et al, 2013). The ability of bacteria to perceive and respond to these factors is imperative for their survival.…”

Latest developments in foodborne pathogen risk assessment

“…For instance, identification of pathways involved in pathogen stress adaptation patterns has been determined by comparative genome analysis in food [30]. More recently, differential gene expression analysis and genome-wide transcriptome analysis have been used to identify food-related stress resistance biomarkers [31][32][33][34].…”