Phenotypic, genotypic, and resistome of mesophilic spore-forming bacteria isolated from pasteurized liquid whole egg

Author(s)

Chincha, Alexandra A. I. A. ; Marone, Marina P. ; Pia, Arthur K. R. ; Freire, Luisa ; Amorim-Neto, Dionisio P. ; Carazzolle, Marcelo F. ; Sant'Ana, Anderson S.

• Document type: Journal article
• Source: Food Research International; v. 184, p. 21-pg., 2024-03-25.

Abstract

The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (n = 200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86 %), followed by Brevibacillus (10 %) and Lysinibacillus (4 %). For the phenotypic characterization, isolates were subjected to various heat shocks, with the most significant reductions observed at 80 degrees C/30 min and 90 degrees C/10 min for isolates recovered from raw materials. On the other hand, the decrease was similar for isolates recovered from raw material and final product at 100 degrees C/5 min and 110 degrees C/5 min. Genotypic genes related to heat resistance (cdnL, spoVAD, dacB, clpC, dnaK, and yitF/Tn1546) were examined for genotypic characterization. The dnaK gene showed a positive correlation with the highest thermal condition tested (110 degrees C/ 5 min), while 100 degrees C/5 min had the highest number of positively correlated genes (clpC, cdnL, yitF/Tn1546, and spoVAD). Whole Genome Sequencing of four strains revealed genes related to sporulation, structure formation, initiation and regulation, stress response, and DNA repair in vegetative cells. The findings of this study indicate that these mesophilic aerobic spore-forming bacteria may adopt several strategies to persist through the process and reach the final product. As the inactivation of these microorganisms during egg processing is challenging, preventing raw materials contamination and their establishment in processing premises must be reinforced. (AU)

• FAPESP's process: 21/15224-8 - From the fields to therapeutic application: investigating the neuroprotective potential of lactic acid bacteria isolated during coffee (Coffea arabica) fermentation on Sporadic Parkinson's Disease
• Grantee: Dionisio Pedro Amorim Neto
• Support Opportunities: Scholarships in Brazil - Doctorate