scholarly journals Antimicrobial activity of lactic acid bacteria isolated from locally fermented cow milk products sold in Keffi, Nigeria on clinical bacteria

2021 ◽  
Vol 8 (2) ◽  
pp. 078-084
Author(s):  
MD Makut ◽  
NJ Emelogu ◽  
IK Ekeleme ◽  
JE Owuna ◽  
FU Alfa

Lactic acid bacteria (LAB) are renowned for the potential of producing antimicrobial compounds. This study focuses on isolation and antimicrobial effect of lactic acid bacteria isolated from locally fermented cow milk products (Nono, Kindirmo and Maishanu). The antimicrobial effect of the LAB isolates against clinical test isolates was also investigated. Fifty (50) samples each of Nono and Kindirmo, and twenty-five (25) of Maishanu were collected from cow milk products sellers in Keffi, Nasarawa State Nigeria. Standard microbiological methods were used for the isolation and identification of Lactic acid bacteria from fermented cow milk products. The percentage isolation rate of Lactobacillus species from Nono and Kindirmo showed that 52.0% were isolated from Nono and 58.0% from kindirmo. The highest percentage occurring Lactobacillus species from Nono was Lactobacillus plantarum (14.0%) and the highest percentage occurring Lactobacillus species from kindirmo was Lactobacillus delbrueckii (16.0%). The Lactobacillus species isolated were screened for antibacterial activity and it was observed that seven (7) were able to show inhibition zones. The antimicrobial effect of the LAB culture supernatant against clinical isolates of Staphylococcus aureus, Escherichia coli and Shigella dysenteriae was investigated using agar diffusion technique. The highest 22.00mm was observed by Lactobacillus delbrueckii and Lactobacillus delbrueckii against Shigella dysenteriae, while the least inhibition zone of 15.00mm was observed by Lactobacillus delbrueckii and Lactobacillus acidophilus against E. coli. In conclusion, the zones of inhibition observed in this research strongly suggest that various antimicrobial compounds (lactic acid, acetic acid, propionic acid and bacteriocins) produced during the fermentation process are potent in the control of growth of the test bacteria.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Yeshambel Taye ◽  
Tadesse Degu ◽  
Haben Fesseha ◽  
Mesfin Mathewos

Lactic acid bacteria (LAB) have long been consumed by people in several fermented foods such as dairy products. A study was conducted on lactating dairy cows to isolate and characterize LAB from dairy products found in and around Bahir-Dar city, North Western Ethiopia. Milk and milk products were randomly collected from dairy farms, milk vending shops, individual households, and supermarkets for bacteriological investigations. A total of sixteen samples were taken from different sources and cultured on different selective media: de Man, Rogosa, and Sharpe (MRS) agar for Lactobacillus spp.; M17 agar for Lactococcus spp.; Rogasa SL agar for Streptococci spp.; and MRS supplemented with cysteine (0.5%) for Bifidobacteria spp. Different laboratory techniques were implemented for LAB isolation and identification. A total of 41 bacterial isolates were grouped under five different genera of LAB and Bifidobacteria spp. were identified based on the growth morphology on the selective media, growth at a different temperature, gas production from glucose, carbohydrate fermentation, and other biochemical tests. LAB genera such as Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus, and Bifidobacterium spp. were isolated and identified from raw milk, cheese, and yogurt. Based on the current study, the majority of the LAB (24.38%) was isolated from cheese and yogurt. Among these, Lactobacillus, Lactococcus (21.94%), Streptococcus (19.51%), Leuconostoc (14.64%), Bifidobacteria (12.19%), and Pediococcus (7.31%) spp. were also identified from these products. Furthermore, based on the bacterial load count and different identification methodologies, our study revealed that Lactobacillus spp. were the dominant LAB isolated from milk and milk products. As a result, since there are few studies on the isolation and identification of lactic acid bacteria from dairy products in Ethiopia, more research studies are needed to complete the identification and characterization to species level and their possible role as probiotics.


2013 ◽  
Vol 62 (3) ◽  
pp. 331-334
Author(s):  
IWONA DROŻDŻ ◽  
MAŁGORZATA MAKAREWICZ ◽  
TADEUSZ TUSZYŃSKI

The aim of this study was to identify various bacteria isolated from grapes and their wines. Additionally we investigated the capacity of lactic acid bacteria for microbiological deacidification of wines produced in Poland. We have identified Oenococcus oeni, Lactobacillus acidophilus and Lactobacillus delbrueckii. During the microbial deacidification process, we observed decreases of total acidity and increases of volatile acidity, with statistically significant changes noted for O. oeni in Marechal Foch and Seyval Blanc, and for Lb. acidophilus in Frontenac. On the other hand, a statistically significant increase in pH was observed in Marechal Foch and Seyval Blanc following deacidification by O. oeni.


2017 ◽  
Vol 10 (4) ◽  
pp. 309-318 ◽  
Author(s):  
P. Dawlal ◽  
C. Brabet ◽  
M.S. Thantsha ◽  
E.M. Buys

Maize, which contributes to a large portion of the African diet and serves as the base substrate for many fermented cereal products, has been reported to be contaminated with fumonisins. This study aimed to evaluate the in vitro ability of predominant lactic acid bacteria (LAB) in African traditional fermented maize based foods (ogi and mahewu) to bind fumonisin B1 (FB1) and B2 (FB2), as well as the stability of the complex at different pH and temperatures, in particular observed during ogi fermentation and under its storage conditions (time, temperature). The percentage of bound fumonisins was calculated after analysing the level of fumonisins not bound to LAB after a certain incubation time, by HPLC. The results revealed the ability of all tested LAB strains to bind both fumonisins, with binding efficiencies varying between strains and higher for FB2. Binding of fumonisins increased with a decrease in pH from 6 to 4 (observed during the ogi fermentation process) and from 4 to 2 (acidic pH in the stomach), and an increase in temperature (from 30 to 37 °C). The percentage of FB1 and FB2 bound to LAB at pH 4 decreased after 6 days of storage at 30 °C for all LAB strains, except for Lactobacillus plantarum (R1096) for which it increased. Lactobacillus species (L. plantarum and Lactobacillus delbrueckii) were the most efficient in binding FB1 and FB2, whereas Pediococcus sp. was less efficient. Therefore, the Lactobacillus strains tested in this study can be recommended as potential starter cultures for African traditional fermented maize based foods having detoxifying and probiotic properties.


Biomolecules ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 752 ◽  
Author(s):  
Ivan Kushkevych ◽  
Věra Kotrsová ◽  
Dani Dordević ◽  
Leona Buňková ◽  
Monika Vítězová ◽  
...  

The gut microbiota is a complex component of humans that depends on diet, host genome, and lifestyle. The background: The study purpose is to find relations between nutrition, intestinal lactic acid bacteria (LAB) from various environments (human, animal intestine, and yogurt) and sulfate-reducing microbial communities in the large intestine; to compare kinetic growth parameters of LAB; and to determine their sensitivity to different concentration of hydrogen sulfide produced by intestinal sulfate-reducing bacteria. Methods: Microbiological (isolation and identification), biochemical (electrophoresis), molecular biology methods (DNA isolation and PCR analysis), and statistical processing (average and standard error calculations) of the results were used. The results: The toxicity of hydrogen sulfide produced by sulfate-reducing bacteria, the survival of lactic acid bacteria, and minimal inhibitory concentrations (MIC) were determined. The measured hydrogen sulfide sensitivity values were the same for L. paracasei and L. reuteri (MIC > 1.1 mM). In addition, L. plantarum and L. fermentum showed also a similar sensitivity (MIC > 0.45 mM) but significantly (p < 0.05) lower than L. reuteri and L. paracasei (1.1 > 0.45 mM). L. paracasei and L. reuteri are more sensitive to hydrogen sulfide than L. fermentum and L. plantarum. L. pentosus was sensitive to the extremely low concentration of H2S (MIC > 0.15 mM). Conclusions: The Lactobacillus species were significantly sensitive to hydrogen sulfide, which is a final metabolite of intestinal sulfate-reducing bacteria. The results are definitely helpful for a better understanding of complicated interaction among intestinal microbiota and nutrition.


Author(s):  
Sevim Erdoğmuş ◽  
Uğur Erişmiş ◽  
Cevdet Uğuz

In this study, 30 lactic acid bacteria (LAB) were isolated from 20 different fermented meat products obtained from the Afyonkarahisar province (Turkey). Molecular identification of these isolates was performed by amplification of the 16S rDNA gene using the polymerase chain reaction (PCR) method. LAB isolated from 'sucuk' (spicy and fermented sausage) samples were identified as Enterococcus faecalis (2 isolates), Enterococcus durans (1 isolate), Lactobacillus sakei (3 isolates), Lactobacillus curvatus (2 isolates), Weissella viridescens (3 isolates), Weissella cibaria (2 isolates) and Weissella hellenica (1 isolate). LAB, isolated from salami samples, were identified as W. viridescens (1 isolate), E. durans (3 isolates), Leuconostoc mesenteroides (4 isolates), Carnobacterium maltaromaticum (1 isolate), Macrococcus caseolyticus (1 isolate). Also, LAB, isolated from sausages samples, were identified as E. faecalis (1 isolate), E. durans (4 isolates), Lactobacillus plantarum (1 isolate). Both agar spot and agar well diffusion assay methods were used to determine the antimicrobial activity of the LAB isolates. Isolates of LAB showed higher antimicrobial activity against Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Klebsiella pneumoniae NRRL B 4420, Pseudomonas aeruginosa ATCC 11778, Streptococcus faecalis NRRL B 14617 than against Escherichia coli ATCC 35218 and Bacillus subtilis NRS 744. Results showed that the LAB isolates produced antimicrobial substances that have a potential for different industrial and biotechnological uses.


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