scholarly journals Antihypertensive Peptide Activity in Dutch-Type Cheese Models Prepared with Different Additional Strains of Lactobacillus Genus Bacteria

2019 ◽  
Vol 9 (8) ◽  
pp. 1674 ◽  
Author(s):  
Monika Garbowska ◽  
Antoni Pluta ◽  
Anna Berthold-Pluta

The objective of this study was to determine the proteolytic activity of bacterial strains from the genus Lactobacillus and their capability in producing peptide inhibitors of angiotensin-converting enzyme (ACE) in cheese models prepared with their addition. After 5 weeks of ripening, all cheese models studied were characterized by a high ability of angiotensin convertase inhibition which exceeded 80%. The use of the adjunct bacterial cultures from the genus Lactobacillus contributed to lower IC50 values compared with the value determined for the control cheese model. The proteolytic activity of model cheeses varied in their increase through the period of ripening, with changes in values dependent on the adjunct lactic acid bacteria (LAB) strain used for cheesemaking. Starting from the first week of ripening, the lowest proteolytic activity was demonstrated for the control cheese models, whereas the highest activity throughout the ripening period was shown for the cheese models with the addition of Lb. rhamnosus 489.

2016 ◽  
Vol 88 (3) ◽  
pp. 507-516 ◽  
Author(s):  
Shiro Takeda ◽  
Hisashi Matsufuji ◽  
Koji Nakade ◽  
Shin-ichi Takenoyama ◽  
Abdulatef Ahhmed ◽  
...  

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 963
Author(s):  
Jon Kepa Izaguirre ◽  
Leire Barañano ◽  
Sonia Castañón ◽  
Itziar Alkorta ◽  
Luis M. Quirós ◽  
...  

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical and medical applications. In soybeans and in unfermented soy foods, isoflavones are normally present as glycosides. Isoflavone glycosides can be enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of isoflavones in humans requires the bioconversion of isoflavone glycosides to isoflavone aglycones through the activity of the enzyme β-glucosidase. The objective was to assess the capacity of 42 bacterial strains (belonging to Lactobacillus, Streptococcus and Enterococcus) to produce β-glucosidase activity. The strain that showed the highest β-glucosidase activity (Lactobacillus plantarum 128/2) was then used for the optimization of the bioconversion of genistin and daidzin present in commercial soymilk to their aglycone forms genistein and daidzein. The contribution of process parameters (temperature, inoculum size, time) to the efficiency of such bioactivation was tested. Lactobacillus plantarum 128/2 was able to completely bioactivate soymilk isoflavones under the following conditions: 25 °C temperature, 2% inoculum size and 48 h process time. These results confirm the suitability of lactic acid bacteria for the bioactivation of isoflavones present in soymilk and provide an interesting candidate (L. plantarum 182/2) for food industries to perform this transformation.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Shiara Ramdath ◽  
John Mellem ◽  
Londiwe Simphiwe Mbatha

Health issues involving inadequate treatment of diseases such as cancer and microbial infections continue to be the subject of much ongoing recent research. Biosynthesized silver nanoparticles (AgNPs) were characterized using Transmission Electron Microscopy (TEM), Zeta Sizer, Ultraviolet (UV), and Fourier Transform Infrared (FTIR) spectroscopy. Their antimicrobial activity was evaluated on selected Gram-positive and Gram-negative bacterial strains, using the disc diffusion and broth dilution assays. Cell viability profiles were evaluated using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and apoptosis studies on selected human noncancer and cancer cells. The biosynthesized AgNPs were evaluated to be spherical clusters, with sizes between 40 and 70 nm. The absorption peak at 423 nm and the presence of polyphenols confirmed the synthesis and stabilization of these tested AgNPs. The AgNPs showed a good stability of −23.9 ± 1.02 mV. Good antimicrobial activity (6.0–18.0 mm) was seen on all tested bacteria at a minimum inhibitory concentration (MIC) ranging from 5 to 16 μg/ml, with the highest activity seen against Gram-negative Escherichia coli (18 ± 0.5 mm), and the lowest activity was seen against Gram-positive Listeria monocytogenes (6.0 ± 0.4 mm) after treatment with the AgNPs. These NPs showed a concentration-dependent and cell-specific cytotoxicity with low IC50 values (41.7, 56.3, and 63.8 μg/ml). The NPs were well tolerated by tested cells as indicated by a more than 50% cell viability at the high dose tested and low apoptotic indices (<0.2). These findings indicated that these biosynthesized AgNPs showed great potential as effective antibacterial agents and anticancer drug delivery modalities.


2018 ◽  
Vol 6 (2) ◽  
pp. 500-508
Author(s):  
Julie Ann A. Arcales ◽  
Garner Algo L.Alolod

Isolation and characterization of bacteria in food products are important to determine and distinguish the beneficial or harmful effects of microbiota in certain samples. Lactic acid bacteria in food products had long been associated to good factors as food preservatives and with added fermentation metabolites. This study isolated and characterized lactic acid bacteria from burong bangus. The culture and purification process of bacteria isolation resulted to 4 strains of lactic acid bacteria namely Enterococcus faecalis, Tetragenococcus muriaticus, Lactobacillus delbrueckii subp. delbrueckii and Carnobacterium divergens. High enzymatic activity were observed with E. faecalis particularly on lipase and protease assay. While C. divergens have no enzymatic activity against lipase, protease, amylase and cellulase. The antimicrobial property of L. delbrueckii is only susceptible to amoxicillin unlike the other three bacteria isolates. No antagonistic activity were observed with the four bacterial strains against Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The result of this study showed promising benefits to the industry especially in developing countries like the Philippines because population are not yet so aware of this organisms and the benefits that can be derived through their consumption.


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.


Author(s):  
Roseline Eleojo Kwasi ◽  
Iyanuoluwa Gladys Aremu ◽  
Qudus Olamide Dosunmu ◽  
Funmilola A. Ayeni

Background: Ogi constitutes a rich source of lactic acid bacteria (LAB) with associated health benefits to humans through antimicrobial activities. However, the high viability of LAB in Ogi and its supernatant (Omidun) is essential. Aims: This study was carried out to assess the viability of LAB in various forms of modified and natural Ogi and the antimicrobial properties of Omidun against diarrhoeagenic E coli. Methods and Material: The viability of LAB was assessed in fermented Ogi slurry and Omidun for one month and also freeze-dried Ogi with and without added bacterial strains for two months. A further 10 days viability study of modified Omidun, refrigerated Omidun, and normal Ogi was performed. The antimicrobial effects of modified Omidun against five selected strains of diarrhoeagenic E. coli (DEC) were evaluated by the co-culture method. Results: Both drying methods significantly affected carotenoids and phenolic compounds. The Ogi slurry had viable LAB only for 10 days after which, there was a succession of fungi and yeast. Omidun showed 2 log10cfu/ml reduction of LAB count each week and the freeze-dried Ogi showed progressive reduction in viability. Refrigerated Omidun has little viable LAB, while higher viability was seen in modified Omidun (≥2 log cfu/ml) than normal Omidun. Modified Omidun intervention led to 2-4 log reduction in diarrhoeagenic E. coli strains and total inactivation of shigella-toxin producing E. coli H66D strain in co-culture. Conclusions: The consumption of Ogi should be within 10 days of milling using modified Omidun. There are practical potentials of consumption of Omidun in destroying E. coli strains implicated in diarrhea. Keywords: Ogi, Omidun, lactic acid bacteria, diarrhoeagenic Escherichia coli strains, Viability.


2011 ◽  
Vol 74 (4) ◽  
pp. 631-635 ◽  
Author(s):  
VASILIKI A. BLANA ◽  
AGAPI I. DOULGERAKI ◽  
GEORGE-JOHN E. NYCHAS

Fifteen fingerprints (assigned to Leuconostoc spp., Leuconostoc mesenteroides, Weissella viridescens, Leuconostoc citreum, and Lactobacillus sakei) of 89 lactic acid bacteria (LAB) isolated from minced beef stored under modified atmospheres at various temperatures were screened for their ability to exhibit autoinducer-2 (AI-2)–like activity under certain growth conditions. Cell-free meat extracts (CFME) were collected at the same time as the LAB isolates and tested for the presence of AI-2–like molecules. All bioassays were conducted using the Vibrio harveyi BAA-1117 (sensor 1−, sensor 2+) biosensor strain. The possible inhibitory effect of meat extracts on the activity of the biosensor strain was also evaluated. AI-2–like activity was observed for Leuconostoc spp. isolates, but none of the L. sakei strains produced detectable AI-2–like activity. The AI-2–like activity was evident mainly associated with the Leuconostoc sp. B 233 strain, which was the dominant isolate recovered from storage at 10 and 15°C and at the initial and middle stages of storage at chill temperatures (0 and 5°C). The tested CFME samples displayed low AI-2–like activity and inhibited AI-2 activity regardless of the indigenous bacterial populations. The LAB isolated during meat spoilage exhibited AI-2–like activity, whereas the LAB strains retrieved depended on storage time and temperature. The production of AI-2–like molecules may affect the dominance of different bacterial strains during storage. The results provide a basis for further research concerning the effect of storage temperature on the expression of genes encoding AI-2 activity and on the diversity of the ephemeral bacterial population.


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