Ultrasound Attenuation Improves Some Surface Properties of the Probiotic Strain Lacticaseibacillus casei ATCC 393

Abstract

Ultrasound attenuation has been recently proposed as a tool to modulate probiotic metabolism. The study aimed to characterize the response of the probiotic Lacticaseibacillus casei ATCC 393 to sonication. Two ultrasound treatments were tested (57 W, duty cycle 50%, 6 or 8 min). Attenuation was assessed as a pH decrease in MRS broth after 6 and 24 h of incubation at 37 °C. Cultivability was evaluated by plate count immediately after sonication and by growth index on overnight cultures. Surface changes were determined by auto-aggregation, hydrophobicity, biofilm production tests, and by membrane damages. The 6 min treatment induced a temporary attenuation, while a prolongated exposure to sonic waves caused major attenuation effects (ΔpH 0.97 after 24 h). Both sonication treatments affected probiotic cultivability with a significant (p < 0.05) reduction of plate counts and an alteration of the growth index. Although auto-aggregation was negatively affected upon sonication, the hydrophobicity and biofilm production were improved with no significant differences (p > 0.05) between the sonicated samples. Moreover, sonicated L. casei ATCC 393 resulted in increased membrane permeability. These results suggest that ultrasound technology can be successfully used to modulate the L. casei ATCC 393 fermentative metabolism and to improve its surface properties.

Ultrasound can increase biofilm formation by Lactiplantibacillus plantarum and Bifidobacterium spp.

“…This effect on hydrophobicity could be the reason beyond the action on Bifidobacteria , as in the past an increased cell surface hydrohobicity of Limosilactibacillus reuteri and Propionibacteria was found by authors after US treatments ( Racioppo et al, 2017 ; Bevilacqua et al, 2019b ). This effect on hydrophobicity was also reported for Lacticaseibacillus casei ATCC 393 ( Giordano and Mauriello, 2023 ), also coupled with an increased membrane permeability.…”

“…Autoaggregation is a desirable property since it results in increased adhesion of microbial cells to the intestinal mucosa, providing advantages in colonization of the gastrointestinal tract ( García-Cayuela et al, 2014 ; Trunk et al, 2018 ), as well as in the ability to survive in harsh environments. However, this effect on auto-aggregation is controversial and conflicting results have been found in the literature, as stressed by Giordano and Mauriello (2023) .…”

“…High-intensity US could damage membranes causing viability loss and release of cellular components, while low-intensity US could stimulate bacterial metabolism ( Bevilacqua et al, 2019a ). First, this dual effect was reviewed by Erriu et al (2014) for microbial biofilms, while recent studies have shown the positive effect of US on biofilm stability of Acidipropionibacterium jensenii , Propionibacterium freudenreichi ( Bevilacqua et al, 2019b ), Limosilactobacillus reuteri ( Racioppo et al, 2017 ), and Lacticaseibacillus casei ( Giordano and Mauriello, 2023 ).…”

Transcriptomic analysis reveals differential gene expression patterns of Lacticaseibacillus casei ATCC 393 in response to ultrasound stress

“…In our previous study also performed on Lc. casei ATCC 393 [36] , we showed that 6 and 8 min of sonication induced a transient and a prolonged attenuation effect, respectively. The critical evaluation of the data collected in the previous and current studies allow us to have a deeper understanding of effects of ultrasound on this probiotic strain at metabolic level.…”

Effect of Ultrasound Application at Different Duration on Probiotic and Antioxidant Properties of S. boulardii

“…(Speranza vd., 2020) ultrases işleminin S. cerevisiae'nın farklı suşlarının agregasyon özelliğini farklı düzeylerde etkilediğini ve bazı suşlar için bizim çalışmamızda da olduğu gibi agregasyon özelliğini arttırdığını bildirmiştir. Bununla birlikte (Giordano & Mauriello, 2023) ultrases işleminin Lacticaseibacillus casei'nin agregasyon özelliği üzerinde negatif bir etkisinin olduğunu ve dolayısıyla agregasyon yüzdesini azalttığını bildirmişlerdir. Elde edilen bulgular ve literatür verileri ultrases işleminin mikroorganizmaların agregasyon özelliğini farklı düzeylerde etkileyebileceğini göstermekte ve sonuçlar suş bazında değişiklik gösterebilmektedir.…”