The simultaneous utilization of kinetic analysis and flow cytometry in the assessment of Lactobacillus rhamnosus ATCC 7469 physiological states produced by increasing oxygen limitation levels and lactic acid accumulation

2013 ◽  
Vol 74 ◽  
pp. 54-59 ◽  
Author(s):  
Teresa Lopes da Silva ◽  
Susana Marques ◽  
Luis Alves ◽  
José Carlos Roseiro
Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1343
Author(s):  
Lihua Liu ◽  
Chenyi Zhang ◽  
Huimin Zhang ◽  
Guoqiang Qu ◽  
Chun Li ◽  
...  

Apple pomace, the main by-product in apple processing, is a cheap source of bioactive compounds that could be used in the food industry. However, the value of this by-product is still far from being fully realized. In this study, 11 strains of Lactobacillus strains were assayed for β-glucosidase activity, and only Lactobacillus rhamnosus L08 (L. rhamnosus L08) showed high cell-membrane associated β-glucosidase activity. We then evaluated the effects of fermentation of apple pomace using the selected strain, focusing on the biotransformation of polyphenols and antioxidant capacity. We found that L. rhamnosus L08 fermentation significantly reduced the contents of quercitrin and phlorizin in apple pomace, while increasing the contents of quercetin and phloretin. The contents of gallic acid, epicatechin acid, caffeic acid, and ferulic acid were also increased in apple pomace after fermentation. In addition, the antioxidant activities of apple pomace were enhanced during fermentation, based on the bioconversion of phenolic profiles. Our results demonstrate that lactic acid bacteria fermentation is a promising approach to enhance the bioactivity of phenolic compounds in apple pomace. Moreover, this study demonstrates that, as a valuable processing by-product with bioactive components, apple pomace can be used in the food industry to provide economic benefits.


2021 ◽  
Vol 9 (6) ◽  
pp. 1225
Author(s):  
Shanshan Zhao ◽  
Fengyuan Yang ◽  
Yuan Wang ◽  
Xiaomiao Fan ◽  
Changsong Feng ◽  
...  

The aim of this study was to gain deeper insights into the dynamics of fermentation parameters and the bacterial community during the ensiling of high-moisture alfalfa. A commercial lactic acid bacteria (YX) inoculant was used as an additive. After 15 and 30 days of ensiling, the control silage (CK) exhibited a high pH and a high concentration of ammoniacal nitrogen (NH3-N); Enterobacter and Hafnia-Obesumbacterium were the dominant genera. At 60 d, the pH value and the concentration of NH3-N in CK silage increased compared with 15 and 30 d, propionic acid and butyric acid (BA) were detected, and Garciella had the highest abundance in the bacterial community. Compared with CK silage, inoculation of YX significantly promoted lactic acid and acetic acid accumulation and reduced pH and BA formation, did not significantly reduce the concentration of NH3-N except at 60 d, and significantly promoted the abundance of Lactobacillus and decreased the abundance of Garciella and Anaerosporobacter, but did not significantly inhibit the growth of Enterobacter and Hafnia-Obesumbacterium. In conclusion, high-moisture alfalfa naturally ensiled is prone to rot. Adding YX can delay the process of silage spoilage by inhibiting the growth of undesirable microorganisms to a certain extent.


2005 ◽  
Vol 71 (10) ◽  
pp. 6008-6013 ◽  
Author(s):  
Domitille Fayol-Messaoudi ◽  
Cédric N. Berger ◽  
Marie-Hélène Coconnier-Polter ◽  
Vanessa Liévin-Le Moal ◽  
Alain L. Servin

ABSTRACT The mechanism(s) underlying the antibacterial activity of probiotic Lactobacillus strains appears to be multifactorial and includes lowering of the pH and the production of lactic acid and of antibacterial compounds, including bacteriocins and nonbacteriocin, non-lactic acid molecules. Addition of Dulbecco's modified Eagle's minimum essential medium to the incubating medium delays the killing activity of lactic acid. We found that the probiotic strains Lactobacillus johnsonii La1, Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029, L. casei DN-114 001, and L. rhamnosus GR1 induced a dramatic decrease in the viability of Salmonella enterica serovar Typhimurium SL1344 mainly attributable to non-lactic acid molecule(s) present in the cell-free culture supernatant (CFCS). These molecules were more active against serovar Typhimurium SL1344 in the exponential growth phase than in the stationary growth phase. We also showed that the production of the non-lactic acid substance(s) responsible for the killing activity was dependent on growth temperature and that both unstable and stable substances with killing activity were present in the CFCSs. We found that the complete inhibition of serovar Typhimurium SL1344 growth results from a pH-lowering effect.


2000 ◽  
Vol 27 (8) ◽  
pp. 619-625 ◽  
Author(s):  
Hassan Hajjaj ◽  
Philippe Blanc ◽  
Evelyne Groussac ◽  
Jean-Louis Uribelarrea ◽  
Gérard Goma ◽  
...  

1957 ◽  
Vol 10 (1) ◽  
pp. 51-55 ◽  
Author(s):  
J. Gordon Wells ◽  
Bruno Balke ◽  
Donald D. Van Fossan

Author(s):  
Petr Doležal ◽  
Dušan Kořínek ◽  
Jan Doležal ◽  
Václav Pyrochta

In the experiment was the effect of biological additive on the fermentation quality of crushed maize ears of two hybrids by comparing with the untreated control. The bacterial inoculant „A“ contained selected bacterial strains of Lactobacillus rhamnosus (NCIMB 30121) and Enterococcus faecium (NCIMB 30122). As effective substances of bacterial water–soluble inoculant „B“ were selected bacterial strains of Lactobacillus rhamnosus (NCIMB 30121), Lactobacillus plantarum (DSM 12836), Lactobacillus brevis (DSM 12835), Lactobacillus buchneri (DSM 12856), Pediococcus acidialactici (P. pentosaceus) (DSM 12834). The addition of inoculant „A“ in our experiment conditions increased statistically significantly (P<0.01) the pH value (4.09±0.01), resp. 4.02±0.02 in second trial with Pedro hybrid. The bacterial inoculant „B“ increased significantly (P<0.01) the contents of lactic acid (50.95±0.1.87 g/kg DM), acetic acid (18.61±0.34 g/kg DM), sum of acids (69.55±1.62 g/kg DM) and decreased (P<0.01) in the first trial the ethanol content (5.41±0.45 g/kg DM). The highest DM content (P<0.01) was in all experimental inoculated silages with additive „A“ (54.26±0.86%, and 53.56±0.54%, resp.). The bacterial inoculant „A“ increased significantly (P<0.01) in comparison with control silage in the second trial the content of lactic acid (34.66Ī2.81 g/kg DM), sum of acids (44.68±3.54 g/kg DM), the total acids content (32.87±2.88 g/kg DM), and ethanol content (17.33±0.79 g/kg DM). The inoculation positive effect was demonstrated in reduction of ethanol amount and of total acid production. The pH value of inoculated silages was not significantly lower than that in the control silage.


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