Enhanced Inactivation of &lt;i&gt;Bacillus subtilis&lt;/i&gt; Spores by Carbonation with Heating in the Presence of Monoglycerol-caprate

Soh

et al. 2018

FSTR

Self Cite

We investigated the effect of carbonation treatment with heating (CH) in the presence of glycerin fatty acid esters on Bacillus subtilis spores. The inactivation effect of CH was the highest in the presence of monoglycerol monocaprate (MC10). Monoglycerol monolaurate showed the highest bacteriostatic effect. The resistance of spores to CH with MC10 did not change with pre-heat activation. Freshly prepared spores from the surviving spores following CH with MC10 showed resistance similar to that of normal spores. The resistance of spores might be affected by the composition of the spore-forming medium. CH with MC10 enhanced adhesion of MC10 to spores and dipicolinic acid (DPA) release from spores, but did not induce DNA fragmentation. Inactivation of B. subtilis spores by CH with MC10 may be attributable to the impairment of physiological germination and/or decrease in heat resistance, which were induced by enhanced MC10 adhesion and the resultant DPA release.

Section: Discussionsupporting

confidence: 89%

“…DPA release also decreases the heat resistance of spores. We have shown that the heat resistance of B. subtilis spores was decreased to a greater extent by CH with MC10 than by CH alone (Noma et al, 2015). In addition, the inactivation effect of CH with MC10 was more notable at temperatures above 70℃ (Klangpetch et al, 2013).…”

Section: Discussionmentioning

confidence: 77%

Inactivation of Bacillus subtilis Spores by Carbonation with Glycerin Fatty Acid Esters

Hirokado

Soh

et al. 2018

FSTR

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“…These results indicate that the addition of MC10 most efficiently augmented the inactivation effect of CH against the spores of B. subtilis. We also reported that HT alone (80℃ and 0.1 MPa for 30 min) or pressurization alone (80℃ and 5 MPa for 30 min, pressurized by N 2 gas) in the presence or absence of MC10 induced no inactivation effects (Noma et al, 2015). These results showed that the inactivation effect in the presence of MC10 was demonstrated not only by heating or pressurization but by CH.…”

Section: Resultssupporting

confidence: 55%

“…4). In addition, we previously reported that CH in the presence of MC10 inhibited germination of B. subtilis spores (Noma et al, 2015). Therefore, we investigated the inactivation effect of ITWNI, CH at 80℃ and 5 MPa for 10 min, without incubation, followed by HT 2 at 90℃ for 5 min, in the presence of MC10 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Control of Bacillus subtilis Spores by Intermittent Treatment Using Heating after Carbonation in the Presence of Germinants and Bacteriostatic Agents

Tominaga

Igura

et al. 2018

FSTR

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We investigated the inactivation effect of intermittent treatments using carbonation under heating (CH) and second heating (HT), in the presence of germinants or monoglycerol caprate (MC10) on Bacillus subtilis spores. Intermittent treatments by CH, followed by incubation and a second HT, in the presence of germinants showed up to 2.6 log-order inactivation effects on spores. Compared with the effects of glycine, sodium benzoate, and potassium sorbate, MC10 increased the inactivation effect of CH. MC10 decreased the D value and activation energy for inactivation of the spores. Intermittent treatments with MC10, conducted by a CH, followed by HT, inactivated spores by 3.6 log-orders. CH with MC10 induced the release of dipicolinic acid (DPA) and increased the stainability of the spores by DAPI. This suggests that germinationlike phenomena, during CH, were included in the inactivation effects. Spores, which survived the intermittent treatment combined with MC10, did not proliferate in a liquid medium.

“…We have reported that CH induced germination of bacterial spores suspended in water without subsequent cultivation, as confirmed by the reduction in heat resistance, decrease in optical density, and increase in DAPI stainability (Noma et al, 2011). In addition, we also showed that combined treatment of CH and MC10 decreased the heat resistance of B. subtilis spores, as compared to CH alone (Noma et al, 2015).…”

Section: Introductionsupporting

confidence: 64%

Inactivation of Bacillus subtilis Spores by Heat Treatment after Carbonation in the Presence of Monoglycerol Fatty Acid Esters

Tominaga

Qiu-Yue

et al. 2017

FSTR

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The inactivation effect of carbonation under heating (CH) followed by heating (HT 2) in the presence of monoglycerol monocaprate (MC10) or monoglycerol monolaurate (MC12) on Bacillus subtilis spores was investigated. CH (80℃, 5 MPa, 10 min) followed by HT 2 (90℃, 10 min) induced an approximately 5 log order of inactivation in the presence of MC10 or MC12 at 0.05% (w/v). MC12 appeared to have a greater effect on increasing the inactivation effect of CH followed by HT 2 than MC10. Heating, pressurization, and pH downshift involved in CH may play important roles in the high inactivation effect of CH followed by HT 2. As indicated by increased DAPI stainability, CH in the presence of MC10 forced germination. The results show that heating after CH in the presence of MC10 and MC12 effectively inactivated B. subtilis spores under milder heating conditions than conventional autoclaving.