scholarly journals Effect of Pasteurized Low Acidic Indigenous Beverages Produced in Northern Cameroon on Germination of Bacillus and Geobacillus Spores Species

Author(s):  
James Ronald Bayoï ◽  
François-Xavier Etoa

The present study aimed to investigate the influence of three commercially available traditional acidic beverages on spore germination. “Foléré”, red “té” and white “mpedli” sorghum beers have been produced at the laboratory scale assisted by experimented producers, and pH of samples were adjusted at 2.01, 2.63 and 2.8 respectively, then they were pasteurized. The samples produced were tested on four spore-forming bacteria (Bacillus cereus, Bacillus megapterium, Bacillus subtilis and Geobacillus stearothermophilus) and germination was assessed both on culture plate media and by loss of optical density (OD) methods. The results obtained showed that “foléré” at pH 2.01, and both indigenous sorghum red beer at pH 2.63 and white beer at pH 2.8 were effective on spore germination, and efficacy significantly increase (p < 0.05) with the incubation time. The presence of alcohol in the pasteurized white (2.43 %) and red (4.7 %) sorghum beers has significantly (p < 0.05) improved the anti-germinating activity compared to the non-alcoholic “foléré” beverage. The sensitivity of B. cereus and B. subtilis was positively and significantly correlated (r = 0.880; p < 0.01) likewise the sensitivity of B. megapterium and G. stearothermophilus (r = 0.725; p < 0.05), and the activity of traditional white and red sorghum beers was found to be very significant (p < 0.05) for each couple respectively. The loss of OD showed an inhibitory effect of indigenous beverages germination and exhibited a microcycle on all tested spore-forming bacteria. It was concluded that if the good hygiene and manufacturing practices were applied for production of indigenous beverages, they might easily be used as natural preservatives and for prevention of gastroenteritis induced by germination and outgrowth of spore-forming bacteria like B. cereus.

2021 ◽  
Vol 22 (7) ◽  
pp. 3793
Author(s):  
Sophie Blinker ◽  
Jocelyne Vreede ◽  
Peter Setlow ◽  
Stanley Brul

Bacillus subtilis forms dormant spores upon nutrient depletion. Germinant receptors (GRs) in spore’s inner membrane respond to ligands such as L-alanine, and trigger spore germination. In B. subtilis spores, GerA is the major GR, and has three subunits, GerAA, GerAB, and GerAC. L-Alanine activation of GerA requires all three subunits, but which binds L-alanine is unknown. To date, how GRs trigger germination is unknown, in particular due to lack of detailed structural information about B subunits. Using homology modelling with molecular dynamics (MD) simulations, we present structural predictions for the integral membrane protein GerAB. These predictions indicate that GerAB is an α-helical transmembrane protein containing a water channel. The MD simulations with free L-alanine show that alanine binds transiently to specific sites on GerAB. These results provide a starting point for unraveling the mechanism of L-alanine mediated signaling by GerAB, which may facilitate early events in spore germination.


Author(s):  
Yannong Luo ◽  
George Korza ◽  
Angela M. DeMarco ◽  
Oscar P. Kuipers ◽  
Yong‐qing Li ◽  
...  

2006 ◽  
Vol 189 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Venkata Ramana Vepachedu ◽  
Peter Setlow

ABSTRACT The release of dipicolinic acid (DPA) during the germination of Bacillus subtilis spores by the cationic surfactant dodecylamine exhibited a pH optimum of ∼9 and a temperature optimum of 60°C. DPA release during dodecylamine germination of B. subtilis spores with fourfold-elevated levels of the SpoVA proteins that have been suggested to be involved in the release of DPA during nutrient germination was about fourfold faster than DPA release during dodecylamine germination of wild-type spores and was inhibited by HgCl2. Spores carrying temperature-sensitive mutants in the spoVA operon were also temperature sensitive in DPA release during dodecylamine germination as well as in lysozyme germination of decoated spores. In addition to DPA, dodecylamine triggered the release of amounts of Ca2+ almost equivalent to those of DPA, and at least one other abundant spore small molecule, glutamic acid, was released in parallel with Ca2+ and DPA. These data indicate that (i) dodecylamine triggers spore germination by opening a channel in the inner membrane for Ca2+-DPA and other small molecules, (ii) this channel is composed at least in part of proteins, and (iii) SpoVA proteins are involved in the release of Ca2+-DPA and other small molecules during spore germination, perhaps by being a part of a channel in the spore's inner membrane.


2014 ◽  
Vol 83 (4) ◽  
pp. 281-294 ◽  
Author(s):  
Majid Kazzazi ◽  
Fahimeh Dehghanikhah ◽  
Hossein Madadi ◽  
Vahid Hossseininaveh

ABSTRACT Host plant resistance is an environmentally safe method used for reducing a pest population. Basically, when developing resistant cultivars one needs to study the biochemical characteristics of the digestive enzymes in the insect’s midgut. In this study, the activities of α- and β-glucosidase were determined from Leptinotarsa decemlineata midgut using p-nitrophenyl-α-Dglucopyranoside and p-nitrophenyl-β-D-glucopyranoside as substrates respectively. The results showed that the specific activity of α- and β-glucosidase from 4th instar larvae midguts of L. decemlineata were 5.14 and 5.48 Umg-1 protein respectively. The activity of α-glucosidase was optimal at pH 4, whereas the maximum activity of β-glucosidase in the midgut of L. decemlineata occurred at pH 4-5.5. Both enzymes were stable at pH 3-8 over an incubation time of 8 hours. The respective activities of α- and β-glucosidase were at their highest at 45 °C and 50 °C, but they were not stable at 50 °C during an incubation time of 8 days. Furthermore, our data showed that MgCl2, Tris and urea have a moderate but SDS a severe inhibitory effect on enzyme activity. Biochemical characterisation revealed one and three bands of α- and β-glucosidase activities in the midgut of L. decemlineata respectively.


2011 ◽  
Vol 1 ◽  
pp. 792-799 ◽  
Author(s):  
Kai Reineke ◽  
Isabel Doehner ◽  
Daniel Baier ◽  
Alexander Mathys ◽  
Dietrich Knorr

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