scholarly journals Isolation and Identification of Dominant Bacteria from Raw Donkey Milk Produced in a Region of Morocco by QIIME 2 and Evaluation of Their Antibacterial Activity

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Reda Derdak ◽  
Javier Quinteiro ◽  
Souraya Sakoui ◽  
Boutaina Addoum ◽  
Jorge Rodríguez Castro ◽  
...  

Recently, the interest in donkey milk has increased considerably because it proved high nutritive and functional values of their ingredients. Its chemical composition is widely studied, but its microbiota, especially lactic acid bacteria, remains less studied. This study focuses on analyzing, isolating, and identifying lactic acid bacteria and evaluating their capacity to produce biomolecules with antibacterial activity. Among 44 strains identified, 43 are Gram-positive, and most are catalase-negative and cocci-shaped. Five strains were selected to evaluate their antibacterial activity against Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli. Different induction methods allowed to amplify the antibacterial effects against these pathogenic strains.

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Ekawati Purwijantiningsih

AbstractFermented milk products could be found on the marketplace in great quantities of brand and type. Fermented milk has potentials for functional food because it has health benefits for human body and acts as antimicrobial. However from all brands and types, the viability of lactic acid bacteria (LAB) and antibacterial activity is not surely known, especially in Yogyakarta. The aim of this study was to determine the viability of lactic acid bacteria and antibacterial effect to three enteric pathogenic bacteria. Tests were carried out on 18 samples of fermented milk from supermarkets in Yogyakarta. Base on LAB viability test, 12 samples fulfilled the concentration of probiotic bacteria, number of viable bacteria at least 108 CFU/ml. Antibacterial activity from 18 brands against Staphylococcus aureus, Escherichia coli and Salmonella sp. by using well diffusion method. Fermented milk products have different antibacterial activities. Brand R showed the maximum antibacterial effect against the pathogens. It was determined that the most sensitive pathogenic bacteria to milk fermented products were S. aureus, whereas the least sensitive pathogen was Salmonella sp.Keywords: Antibacterial, fermented milk, viability of lactic acid bacteriaAbstrakProduk susu fermentasi dapat ditemukan di pasaran dalam berbagai merk dan jenis. Susu fermentasi tersebut berpotensi sebagai pangan fungsional karena memiliki manfaat kesehatan bagi manusia dan berperan sebagai antimikrobia. Akan tetapi dari berbagai merk dan jenis yang ada belum diketahui secara pasti mengenai viabilitas bakteri asam laktat (BAL) dan aktivitas antibakterinya terutama yang beredar di wilayah Yogyakarta. Penelitian ini bertujuan mengetahui viabilitas BAL dan efek antibakteri terhadap tiga bakteri patogen enterik. Uji dilakukan pada 18 sampel susu fermentasi yang berasal dari supermaket di kota Yogyakarta. Berdasarkan uji viabilitas BAL, ada 12 sampel yang memenuhi standar konsentrasi bakteri probiotik,paling tidak mengandung 108 CFU/ml. Aktivitas antibakteri dari 18 merk diuji terhadap Staphylococcus aureus, Escherichia coli dan Salmonella sp. menggunakan metode difusi sumuran. Produk minuman susu fermentasi memiliki kemampuan antibakteri yang berbeda. Merk R menunjukkan efek antibakteri paling tinggi terhadap beberapa bakteri patogen. Bakteri patogen yang paling sensitif terhadap produk susu fermentasi adalah S. aureus, yang paling tidak sensitif adalah Salmonella sp.Kata kunci: Antibakteri, susu fermentasi, viabilitas BAL


2018 ◽  
Vol 16 (S1) ◽  
pp. S155-S163 ◽  
Author(s):  
S. Mehalaine ◽  
O. Belfadel ◽  
T. Menasria ◽  
A. Messaili

The present study was carried out to determine, for the first time, the chemical composition and antibacterial activity of essential oils derived from the aerial parts of three aromatic plants Thymus algeriensis Boiss & Reut, Rosmarinus officinalis L., and Salvia officinalis L. growing under semiarid conditions. The essential oils were chemically analyzed and identified by gas chromatography (GC) and GC/ mass spectrometry (GC/MS) and their antimicrobial activity was individually evaluated against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa using both agar disk diffusion and agar dilution methods. The major constituents of Thymus algeriensis essential oil were identified as camphor (13.62%), 1,8-cineol (6.00%), borneol (5.74%), viridiflorol (4.00%), and linalool (3.93%). For Rosmarinus officinalis essential oil, 48 compounds were characterized, of which the main constituents were camphor (17.09%), Z-β-ocimene (10.88%), isoborneol (9.68%), α-bisabolol (7.89%), and borneol (5.11%). While, Salvia officinalis essential oil was characterized by β-thujone (16.44%), followed by viridiflorol (10.93%), camphor (8.99%), 1,8-cineol (8.11%), trans-caryophyllene (5.85%), and α-humulene (4.69%) as the major components. Notably, results from antibacterial screening indicated that Thymus algeriensis and Salvia officinalis essential oils exhibited a strong inhibitory effect against both Escherichia coli and Staphylococcus aureus compared to Rosmarinus officinalis essential oil. Further, less activity was recorded against Pseudomonas aeruginosa for the three tested essential oils.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ida B. Christensen ◽  
Charlotte Vedel ◽  
Maja-Lisa Clausen ◽  
Søren Kjærulff ◽  
Tove Agner ◽  
...  

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by an epidermal barrier impairment, as well as a Th2/Th22-skewed immune response, both favoring skin colonization with Staphylococcus aureus. Colonization is strongly related to severity of the disease, and a reduction of S. aureus has been found to alleviate symptoms. Lactic acid bacteria (LAB) produce antimicrobial compounds such as organic acids and bacteriocins and are widely used as probiotics. The aim of this study was to isolate LAB and screen for antibacterial effect specifically toward S. aureus clonal complex type 1. A total of 680 LAB were isolated from fermented vegetables and swab samples from healthy volunteers (vaginal, stool and skin). Screening for antibacterial activity toward S. aureus, narrowed the field of isolates down to four LAB strains with high antibacterial activity. The activity varied according to the specific LAB strain and the origin of the strain. The results suggested different modes of action, including co-aggregation, expression of bacteriocins and production of specific organic acids. However, the ability to acidify the surroundings appeared as the main effect behind inhibition of S. aureus. Broth microdilution assays showed a significant reduction of S. aureus growth when using down to 10% cell free supernatant (CFS). Our results underline the use of specific living LAB or their CFS as potential future treatment strategies to reduce S. aureus colonization of AD skin.


Author(s):  
ROSALINA YULIANA AYEN ◽  
ENDANG KUSDIYANTINI ◽  
SRI PUJIYANTO

Objective: This research aimed to isolate, determine the characteristics of lactic acid bacteria (LAB) of Sui Wu’u from Bajawa, Nusa Tenggara Timur and identify LAB using 16S rRNA potential as antimicrobial activity against pathogenic bacteria. Methods: Sui Wu’u which has been stored for 6 months was obtained from Bajawa district, inoculated on de Man Rogosa-Sharpe Agar (Merck) + 0.5% CaCO3, purification of LAB, characterization of selected isolates, biochemical test, tolerance test for pH, viability to test temperature, and content NaCl, determination of antimicrobial action by the agar well disk diffusion method using antibiotic (Amoxicillin) as a control and as indicator bacteria (Staphylococcus aureus and Escherichia coli) and isolation of genomic 16S rRNA; molecular identification. Results: Based on research results obtained five isolates of LAB, Gram staining the LAB isolated from Sui Wu’u showed that the isolated bacteria (bacilli and coccus) are Gram-positive, catalase-negative and the isolates have tolerance of viability at temperatures of 10°C, 45°C, and 50°C and to salinitas of 4% and 6.5%. The inhibitory zone LAB isolates (2PKT) against E. coli bacteria (20 mm) and S. aureus (12 mm), and (2PKB) against E. coli bacteria (17 mm) and S. aureus (10 mm). The two selected isolates were identified as Lactobacillus fermentum strain HB bacteria with 100% identification value and 98.93% query cover and L. fermentum strain HT with 100% identification value and 99.23% query cover. Conclusion: L. fermentum from Sui Wu’u has antibacterial activity against Staphylococcus aureus and Escherichia coli.


2014 ◽  
Vol 1 (1) ◽  
pp. 27
Author(s):  
Elok Zubaidah ◽  
Erryana Martati ◽  
Ampu Marojahan Resmanto

This research was aimed to study the influence of rice bran and skim milk fermentation media on the growth of lactic acid bacteria and their ability in fermenting complex carbohydrates into short chain fatty acids (SCFA). Indigenous lactic acid bacteria (LAB) were isolated from rice bran and commercial probiotic separately and used for fermenting rice bran and skim milk media. Randomized block design was used with 2 factors i.e. fermenting media type and LAB type. The results showed that fermenting rice bran gave significant effect on the LAB growth, indicated by total LAB cell count, total acid concentration, pH and antibacterial activity. The best treatment was J2-B with total LAB count 1.01 ´ 1010 cfu/mL, total acid 1.14%, pH 3.88 and clear zone diameters against Staphylococcus aureus 13.04 mm, Listeria monocytogenes 12.88 mm, Escherichia coli 12.83 mm and Salmonella typhi 12.53 mm. LAB fermenting rice bran for 48 hours produced lactic acid and SCFA. The highest concentrations of lactic acid (122.1313 mM), acetic acid (10.503 mM), and butyric acid (1.56 mM) were produced by fermentation using LAB J2, L. acidophilus, and L. casei isolate, respectively; whereas the highest propionic acid concentration (6,07 mM) was produced by control fermentation.Keywords: Probiotic, indigenous isolate, rice bran, SCFA, skimmed milk ABSTRAKPeneltian ini bertujuan untuk mengetahui pengaruh dedak dan skim milk sebagai media fermentasi bakteri asam laktat, dan kemampuannya mengubah sumber karbon komplek dedak menjadi asam lemak rantai pendek (short chain fatty acids, SCFA). Bakteri asam laktat lokal diisolasi dari dedak dan probiotik. Desain percobaan adalah acak kelompok dengan 2 faktor, yaitu jenis media fermentasi dan jenis bakteri asam laktat. Hasil penelitian menunjukkan bahwa media fermentasi dengan menggunakan dedak menunjukkan pengaruh yang signifikan terhadap pertumbuhan bakteri yang ditunjukkan dari total sel bakteri asam laktat, total asam yang dihasilkan, pH dan aktivitas antibakteri. Fermentasi dengan menggunakan isolat J2-B menghasilkan total bakteri asam laktat 1,01 ´ 1010 cfu/mL, total asam 1,14%, pH 3,88 dan zona hambatan dengan bakteri uji Staphylococcus aureus 13,04 mm, Listeria monocytogenes 12,88 mm, Escherichia coli 12,83 mm dan Salmonella typhi 12,53 mm. Proses fermentasi bakteri asam laktat menggunakan media dedak selama 48 jam mampu menghasilkan asam laktat dan SCFA. Konsentrasi tertinggi asam laktat (122,13 mM), asam asetat (10,50 mM), dan asam butirat (1,56 mM) masing-masing dihasilkan oleh fermentasi menggunakan BAL J2, isolat L. acidophilus, dan isolat L. casei; sedangkan konsentrasi tertinggi asam propionat (6,07 mM) dihasilkan oleh fermentasi kontrol.Kata kunci: Probiotik, isolat lokal, dedak, SCFA, susu skim


Author(s):  
Ni Made Sri Dwijastuti ◽  
I Nengah Sujaya ◽  
Ni Nengah Dwi Fatmawati

This study aimed to isolate and identify lactic acid bacteria (LAB) that could produce bacteriocins from urutan. Urutan is a Balinese sausage that is traditionally produced and naturally fermented. Urutans used in this study were obtained from several traders in the Baturiti, Mengwi, and Tegallalang region, Bali. More than 300 LAB colonies were isolated and underwent inhibition test against the growth of the indicator bacteria. Crude bacteriocins from two isolates, namely J2 and J6, showed inhibition zones against the growth of Lactobacillus plantarum E12.1 and Escherichia coli ATCC 8739. The J6 isolate also inhibited the growth of Enterococcus faecalis ATCC 29212. Both J2 and J6 were gram-positive, bacilli shaped, and showed negative catalase test. Based on the results of the 16S rDNA gene amplification, the two isolates were identified as Lactobacillus plantarum. Keywords: Lactic Acid Bacteria, Bacteriocin, Lactobacillus plantarum, Urutan


Author(s):  
Selin Kalkan ◽  
Elçin Taş ◽  
Zerrin Erginkaya ◽  
Emel Ünal Turhan

In this study, it was investigated that the inhibition effect of some lactic acid bacteria (Lactobacillus acidophilus NCC68, Lactobacillus casei Shirota, Lactobacillus rhamnosus (Ezal, commercial starter cultures)) which possessed with probiotic characteristics, against Bacillus cereus, Salmonella Enteritidis, Escherichia coli, Escherichia coli 0157:H7 ATCC 35150 and Staphylococcus aureus ATCC 25923. Besides, the inhibitory effect of probiotic cultures which used with meat and meat product additives that garlic extract over the antagonistic effects of sensitive pathogens were investigated in vitro. Consequently, the whole of lactic acid bacteria and garlic extract which were used in this study, showed inhibition effects against all selected pathogenic bacteria. Staphylococcus aureus ATCC 25923 was determined as the most sensitive pathogenic bacteria while Bacillus cereus was the most resistant bacteria against lactic acid bacteria and garlic extract. There was a distinctive increase in inhibition effects were observed by used of a combination with lactic acid bacteria and garlic extract.


Author(s):  
Gislaine Aurelie Kemegne ◽  
Aurore Vanessa Nana Ngahmi ◽  
Abraham Nkoue Tong ◽  
Sylvain Leroy Sado Kamdem ◽  
Jean Justin Essia Ngang

Aims: The aim of this study was to assess the in vitro antibacterial activity of selected antibiotics and essential oils alone or in combination, on selected presumptive probiotic lactic acid bacteria. Study Design: Experimental studies. Place and Duration of Study: Department of Microbiology of the University of Yaounde I between August 2017 and December 2017 (5 months). Methodology: The chemical composition of five essential oils was determined by gas chromatography coupled with Solid-phase micro extraction. Then the sensitivity of four lactic acid bacteria to the essential oils and four antibiotics was assessed by the well diffusion and macrodilution method. Subsequently, two essential oils active on these bacteria and broad spectrum antibiotics were combined according to the central composite design plan. Results: In general, the chemical composition of essential oils is very diverse, with the example of carvacrol found only in Origanum compactum at 53.24% and thymol in Thymus vulgaris at 56.19% and in Origanum compactum at 15.28%. The antibacterial activity shows that the majority of antibiotics used are active on the bacteria in the study compared to the essential oils where two were active (Origanum compactum and Cymbopogon winterianus). The evaluation of the combinations of essential oils and antibiotics in terms of kinetics has given us three cases: the first case is the one with no acidity or no growth at all; the second is the one where growth is normal; the third where growth is delayed with a more pronounced latency phase. Conclusion: This study suggest that the effect of essential oils and medicinal plant used alone or in combination to antibiotics on the gut microbiota have to be evaluated for validation as well as their toxicity activities before using them for human therapy.


2014 ◽  
Vol 66 (3) ◽  
pp. 940-948 ◽  
Author(s):  
L.B. Acurcio ◽  
M.R. Souza ◽  
A.C. Nunes ◽  
D.L.S. Oliveira ◽  
S.H.C. Sandes ◽  
...  

Lactic acid bacteria species were molecularly identified in milk from Lacaune, Santa Inês and crossbred sheep breeds and their in vitro probiotic potential was evaluated. The species identified were Enterococcus faecium (56.25%), E. durans (31.25%) and E. casseliflavus (12.5%). No other lactic acid bacteria species, such as lactobacilli, was identified. Most of the isolated enterococci were resistant to gastric pH (2.0) and to 0.3% oxgall. All tested enterococci were resistant to ceftazidime, oxacillin and streptomycin and sensible to clindamycin, erythromycin and penicillin. The resistance to ciprofloxacin, gentamicin, tetracycline and vancomycin varied among tested species. All tested enterococci strongly inhibited (P<0.05) Escherichia coli and Listeria monocytogenes, moderately inhibited E. faecalis and Staphylococcus aureus and did not inhibit Pseudomonas aeruginosa, Salmonella enterica var. Typhimurium and also one E. durans sample isolated from sheep milk. Four samples of E. faecium, one of E. durans and one of E. casseliflavus presented the best probiotic potential.


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