Elegbeleye, James AyokunleBuys, E.M. (Elna Maria)2021-11-302021-11-302022-01Elegbeleye, 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. 1-9.0023-643810.1016/j.lwt.2021.112487http://hdl.handle.net/2263/82908We 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.en© 2021 Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Thermophilic bacilliBiofilmsSpoilage potentialProteolysisLipolysisArticle