Potential spoilage of extended shelf-life (ESL) milk by Bacillus subtilis and Bacillus velezensis
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Date
Authors
Elegbeleye, James Ayokunle
Buys, E.M. (Elna Maria)
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
We aim to quantify and compare biofilm-induced proteolysis and lipolysis of Bacillus subtilis and Bacillus velezensis with that of the planktonic cells. Planktonic and biofilm cells were enumerated in a flow cytometer after incubation. The concentrations of proteolytic and lipolytic enzymes produced by the submerged biofilm and planktonic cells of the isolates were quantified. There were significant differences (P < 0.05) in the log counts of cells within the biofilms as well as concentrations of enzymes within biofilms and planktonic cells in UHT milk. The enumerated cells ranged from 5.6 log CFU/cm 2 for B168 to 7.4 log CFU/cm 2 for B48, respectively while the highest means of proteolysis and lipolysis were observed in B48 (1034 ρL/CFU) and B50 (34.5ρL/CFU± 0.44) respectively. The result of this study indicated that the spoilage potential for both biofilms and planktonic culture are strain-dependent. The implication to the industry is that weak biofilm formers have better spoilage potential than the strong biofilm formers in spore forming bacilli.
Description
Keywords
Thermophilic bacilli, Biofilms, Spoilage potential, Proteolysis, Lipolysis
Sustainable Development Goals
Citation
Elegbeleye, J.A. & Buys, E.M. 2022, 'Potential spoilage of extended shelf-life (ESL) milk by Bacillus subtilis and Bacillus velezensis', LWT, vol. 153, art. 112487, pp. 1-9.