scholarly journals Optimization of Bacterial Concentrate Media for Lactobacillus Sakei

2022 ◽  
Author(s):  
Nikiforova AP ◽  
Khazagaeva SN ◽  
Khamagaeva IS

Two strains of lactic acid bacteria were selected for the study (Lactobacillus sakei Lsk-45andLactobacillus sakeiDSM 20017). Bacterial media, based on rice and rice flour, were tested as an alternative to media based on whey. A comparison of the different types of media showed that there was better growth of the selected strains on themedium based on rice flour.Statistical analyses, including factorial experiments and response surface analyses, were used to optimizethe composition of the bacterial medium for Lactobacillus sakei propagation. Bacteriological peptone and rice flour were found to be good growth factors for Lactobacillus sakei.For Lactobacillus sakei Lsk-45,better growth was obtained with the use of 7.75-10 g/L of peptone and 57.5-75 g/L of rice flour. For Lactobacillus sakei DSM 20017, better growth was obtained with the use of 7-10 g/L of peptone and 40-75 g/L of rice flour. Keywords: starters, media, Lactobacillus sakei, fermentation,fish products, bacterial strains, lactic acid bacteria

2004 ◽  
Vol 67 (10) ◽  
pp. 2306-2309 ◽  
Author(s):  
RAQUEL HUERTA ◽  
R. JORDANO ◽  
L. M. MEDINA ◽  
CARMEN LÓPEZ

The population dynamic of constitutive biota on 84 samples belonging to two different types of French fermented dry sausages during the ripening process in a pilot-scale ripening chamber was investigated. Samples were analyzed in three steps of their production: fresh product, first drying stage, and finished product. In addition, 180 strains of lactic acid bacteria were identified using a miniaturized biochemical procedure of characterization. In general, the number of lactic acid bacteria that evolved during the ripening process of French dry sausages increased during the first days of the process after which the number of these organisms remained constant at approximately 8 log CFU/g. Lactobacillus sakei and Pediococcus pentosaceus, bacteria added as starter, were the dominant species. Pediococcus urinaeequi, Pediococcus acidilactici, and particularly Lactobacillus curvatus were also present. Finally, we have to take into account that the controlled conditions of the pilot plant generally contribute to the homogenization of the behavior of the starter biota.


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.


Author(s):  
Kang Wook Lee ◽  
Jae Min Shim ◽  
Dong Wook Kim ◽  
Zhuang Yao ◽  
Jeong A. Kim ◽  
...  

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):  
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.


2013 ◽  
Vol 31 (No. 4) ◽  
pp. 323-331 ◽  
Author(s):  
P. Khemariya ◽  
S. Singh ◽  
G. Nath ◽  
A.K. Gulati

Eight isolates of Lactococcus lactis subsp. lactis were isolated and identified by phenotypic and molecular characterisation out of 23 isolates of lactic acid bacteria (LAB) from different dairy and non-dairy sources. Out of eight strains, four were obtained from dairy and four from non-dairy sources. All eight strains of L. lactis subsp. lactis were able to produce zones of inhibition against the Lactobacillus acidophilus NCDC 015. The antimicrobial agent produced by the isolates inhibited the growth of a range of related lactic acid bacteria and certain Gram positive food-borne microorganisms. The antimicrobial agent, i.e. nisin, produced by the strains was confirmed by PCR amplification of nisin gene sequences of 174 bp size. Antibiotic susceptibility test to 21 different types of antibiotics was evaluated. All the isolates were resistant to fosfomycin, cefepime, amikacin, kanamycin, neomycin, nalidixic acid, pipemidic acid, norfloxacin, sulphadiazine, colistin, polymixin, teicoplanin, nystatin, and amphotericin B but susceptible to ampicillin, erythromycin, spiramycin, spectinomycin, ciprofloxacin, rifampicin, and trimethoprim.  


2016 ◽  
Vol 33 (No. 5) ◽  
pp. 458-463 ◽  
Author(s):  
M. Magala ◽  
Z. Kohajdová ◽  
J. Karovičová ◽  
M. Greifová ◽  
J. Hojerová

We investigated the suitability of rice flour for fermented beverage production using various strains of lactic acid bacteria. Fermentation led to a decrease in pH from 5.04&ndash;5.17 to 3.74&ndash;4.35. At the same time, total acidity increased (1.28&ndash;2.59&nbsp;g/l) due to lactic acid (0.59&ndash;2.76 g/l) and acetic acid (0.11&ndash;0.30 g/l) production. Fermentation of rice beverages also caused a gradual decrease in glucose and fructose concentration. Lactic acid bacteria proliferated in the first phases of fermentation, and cell counts reached a maximum after 12 h. The highest growth rate (v<sub>LAB</sub> = 0.44 Log<sub>10</sub> CFU/ml/h) was observed in a sample with the culture of Lactobacillus brevis CCM 1815. Viscosity of beverages decreased significantly after 24&nbsp;h of fermentation. The highest values of sensory parameters were observed in a monoculture of Lactobacillus plantarum CCM 7039 and in a sample with a mixed culture of Lactobacillus plantarum CCM 7039 and Bifidobacterium longum CCM 4990.


2020 ◽  
Vol 87 (1) ◽  
Author(s):  
Yuanting Zhu ◽  
Jinxin Liu ◽  
Julian M. Lopez ◽  
David A. Mills

ABSTRACT Prebiotics are increasingly examined for their ability to modulate the neonate gut microbiota of livestock, and products such as inulin are commonly added to milk replacer used in calving. However, the ability of specific members of the bovine neonate microbiota to respond to inulin remains to be determined, particularly among indigenous lactobacilli and bifidobacteria, beneficial genera commonly enriched by inulin. Screening of Bifidobacterium and Lactobacillus isolates obtained from fresh feces of dairy calves revealed that lactobacilli had a higher prevalence of inulin fermentation capacity (58%) than bifidobacteria (17%). Several Ligilactobacillus agilis (synonym Lactobacillus agilis) isolates exhibited vigorous growth on, and complete degradation of, inulin; however, the phenotype was strain specific. The most vigorous inulin-fermenting strain, L. agilis YZ050, readily degraded long-chain inulin not consumed by bifidobacterial isolates. Comparative genomic analysis of both L. agilis fermenter and nonfermenter strains indicated that strain YZ050 encodes an inulinase homolog, previously linked to extracellular degradation of long-chain inulin in Lacticaseibacillus paracasei, that was strongly induced during growth on inulin. Inulin catabolism by YZ050 also generates extracellular fructose, which can cross-feed other non-inulin-fermenting lactic acid bacteria isolated from the same bovine feces. The presence of specific inulin-responsive bacterial strains within calf gut microbiome provides a mechanistic rationale for enrichment of specific lactobacilli and creates a foundation for future synbiotic applications in dairy calves aimed at improving health in early life. IMPORTANCE The gut microbiome plays an important role in animal health and is increasingly recognized as a target for diet-based manipulation. Inulin is a common prebiotic routinely added to animal feeds; however, the mechanism of inulin consumption by specific beneficial taxa in livestock is ill defined. In this study, we examined Lactobacillus and Bifidobacterium isolates from calves fed inulin-containing milk replacer and characterized specific strains that robustly consume long-chain inulin. In particular, novel Ligilactobacillus agilis strain YZ050 consumed inulin via an extracellular fructosidase, resulting in complete consumption of all long-chain inulin. Inulin catabolism resulted in temporal release of extracellular fructose, which can promote growth of other non-inulin-consuming strains of lactic acid bacteria. This work provides the mechanistic insight needed to purposely modulate the calf gut microbiome via the establishment of networks of beneficial microbes linked to specific prebiotics.


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