scholarly journals Evaluation of bacteriocin-producing lactic acid bacteria strains isolated from “nem chua Thu Duc”

2021 ◽  
Vol 20 (02) ◽  
pp. 62-68
Author(s):  
Phuong T. Nguyen

This study aimed to select some lactic acid bacteria (LAB) strains to produce bacteriocin isolated from two different local brand names of nem chua Thu Duc, a Vietnamese traditional fermented meat product. Eight different LAB strains were isolated from products. However, only Pediococcus pentosaceus isolated from 72-h fermented “Ba Chin” products and Weissella paramesenteroides isolated from 120-h fermented “Diem” products were selectively screened for their bacteriocin production. The antimicrobial activity was detected by the agar diffusion method against Escherichia coli ATCC 25922, Salmonella enterica serovar Typhimurium ATCC 13076, Staphylococcus aureus ATCC 6538, and Bacillus cereus ATCC 25924 used as target strains. Bacteriocin of Pediococcus pentosaceus strain showed a high antibacterial ability with a sterile ring diameter that produces an average of 12.20 - 16.07 mm. Bacteriocin of Weissella paramesenteroides strain only showed inhibitory activity on the growth of indicator microorganisms with an average inhibitory ring diameter of 9.75 - 15.27 mm. In conclusion, it seems like both bacteriocin-producing P. pentosaceus and W. paramesenteroides give potential applications as a starter culture, bio-preservation and bio-safety control in fermented meat as well as other kinds of fermented foods.

Author(s):  
Sokvibol Chuob ◽  
Arunya Prommakool ◽  
Chuleeporn Chumnanka ◽  
Chintana Tayuan ◽  
Arpassorn Sirijariyawat ◽  
...  

Fish paste product is considered an important food in Cambodia. However, the status of antimicrobial susceptibility of microbes in this product are a concern. This study aimed to isolate lactic acid bacteria (LAB) from Cambodian fish paste and to investigate their resistant property of antibiotics. Fifteen LABs were isolated with cell forms of 14 as cocci and 1 as rods. Isolates of the bacteria were identified as Staphylococcus piscifermentans (14 strains) and Lactobacillus plantarum (1 strain). Using the disk diffusion method, the resistance was investigated of the 15 LAB isolate strains to eight clinically crucial antibiotics: penicillin (Pen), ampicillin (Amp), erythromycin (Ery), tetracycline (Tet), vancomycin (Van), streptomycin (Str), sulfamethoxazoletrimethoprim (Sul) and metronidazole (Met). It was found that all 15 LAB isolates were resistant to Met. One isolate strain was resistant to Pen, Amp, Tet, Str and Sul. Furthermore, 7 and 2 isolate strains were resistant to Tet and Van, respectively. All 15 isolate strains were sensitive to Str and Ery. The LAB isolate strains were sensitive to Pen, Amp, Sul (14 strains), Tet (6 strains) and Van (13 strains). These results showed that 14 of the LAB isolate strains were sensitive to 5 antibiotics (Pen, Amp, Ery, Str and Sul) and could be considered as strains for utilization as starter culture for fish fermentation. Additionally, these finding will be conduct to assess the antibiotic resistance incidences of LABs in Cambodian fermented foods.


2018 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Fathyah Hanum Pamungkaningtyas ◽  
Mariyatun Mariyatun ◽  
Rafli Zulfa Kamil ◽  
Ryan Haryo Setyawan ◽  
Pratama Nur Hasan ◽  
...  

Lactic acid bacteria have been isolated from several Indonesian indigenous fermented foods and screened for the potential strains as probiotic candidates. The aim of this study was to evaluate sensory properties and respondents’ preference of yogurt-like set and yogurt-like drink with various Indonesian indigenous probiotic strains produced by dairy industry. Indigenous probiotics of Lactobacillus plantarum MUT-7 and Lactobacillus plantarum DAD-13 were used to produce yogurt-like set and yogurt-like drink. Family perception toward yogurt-like drink was performed in Yogyakarta involving 100 family members. The yogurt-like products were also compared to yogurt containing commercial Lactobacilus bulgaricus and Streptococus thermophilus or commercial yogurt produced by dairy company. Several sensory evaluation toward sensory properties and panelist’s preference were performed in different cities.  The result showed that the indigenous probiotic L. plantarum DAD-13 and L. plantarum MUT-7 were potential to be used as a starter culture for the production of yogurt-like set and yogurt-like drink. The combination of indigenous probiotics and indigenous lactic acid bacteria S. thermophilus DAD-11 resulted in better sensory properties of yogurt set compared to combination of L. bulgaricus and S. thermophilus. 


2012 ◽  
Vol 79 (2) ◽  
pp. 201-208 ◽  
Author(s):  
Micaela Pescuma ◽  
Elvira M. Hébert ◽  
Elena Bru ◽  
Graciela Font de Valdez ◽  
Fernanda Mozzi

The high nutritional value of whey makes it an interesting substrate for the development of fermented foods. The aim of this work was to evaluate the growth and proteolytic activity of sixty-four strains of lactic acid bacteria in whey to further formulate a starter culture for the development of fermented whey-based beverages. Fermentations were performed at 37°C for 24 h in 10 and 16% (w/v) reconstituted whey powder. Cultivable populations, pH, and proteolytic activity (o-phthaldialdehyde test) were determined at 6 and 24 h incubation. Hydrolysis of whey proteins was analysed by Tricine SDS-PAGE. A principal component analysis (PCA) was applied to evaluate the behaviour of strains. Forty-six percent of the strains grew between 1 and 2 Δlog CFU/ml while 19% grew less than 0·9 Δlog CFU/ml in both reconstituted whey solutions. Regarding the proteolytic activity, most of the lactobacilli released amino acids and small peptides during the first 6 h incubation while streptococci consumed the amino acids initially present in whey to sustain growth. Whey proteins were degraded by the studied strains although to different extents. Special attention was paid to the main allergenic whey protein, β-lactoglobulin, which was degraded the most byLactobacillus acidophilusCRL 636 andLb. delbrueckiisubsp.bulgaricusCRL 656. The strain variability observed and the PCA applied in this study allowed selecting appropriate strains able to improve the nutritional characteristics (through amino group release and protein degradation) and storage (decrease in pH) of whey.


2021 ◽  
Author(s):  
Luciano Lopes Queiroz ◽  
Christian Hoffmann ◽  
Gustavo Augusto Lacorte ◽  
Bernadette Dora Gombossy de Melo Franco ◽  
Svetoslav Dimitrov Todorov

Boza is a traditional low-alcohol fermented beverage from the Balkan Peninsula, frequently explored as a functional food product. The product is rich in Lactic Acid Bacteria (LAB) and some of them can produce bacteriocins. In this study, a sample of Boza from Belogratchik, Bulgaria, was analyzed for the presence of bacteriocinogenic LAB, and after analyses by RAPD-PCR, three representative isolates were characterized by genomic analyses, using whole genome sequencing. Isolates identified as Pediococcus pentosaceus ST75BZ and Pediococcus pentosaceus ST87BZ contained operons encoding for bacteriocins pediocin PA-1 and penocin A, while isolate identified as P. acidilactici ST31BZ contained only the operon for pediocin PA-1 and a CRISPR/Cas system for protection against bacteriophage infection. The antimicrobial activity of bacteriocins produced by the three isolates was inhibited by treatment of the cell-free supernatants with proteolytic enzymes. The produced bacteriocins inhibited the growth of Listeria monocytogenes, Enterococcus spp. and some Lactobacillus spp., among other tested species. The levels of bacteriocin production varied from 3200 AU/ml to 12800 AU/ml recorded against L. monocytogenes 104, 637 and 711, measured at 24 h of incubation at 37oC. All bacteriocins remained active after incubation at pH 2.0 to 10.0. The activity mode of the studied bacteriocins was bactericidal, as determined against L. monocytogenes 104, 637 and 711. In addition, bactericidal activity was demonstrated using a cell leakage β-galactosidase assay, indicating a pore formation mechanism as a mode of action. The present study highlights the importance of combining metagenomic analyses and traditional microbiological approaches as way of characterizing microbial interactions in fermented foods.


2018 ◽  
Vol 21 ◽  
pp. 34-44 ◽  
Author(s):  
Digambar Kavitake ◽  
Sujatha Kandasamy ◽  
Palanisamy Bruntha Devi ◽  
Prathapkumar Halady Shetty

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Michael Ukwuru ◽  
Ome Kalu Achi ◽  
Uchechi Nnambuihe Ekwenye

Fermented foods are consumed by a very large population in Africa but the products have many drawbacks ranging from shelf life instability to contamination and toxicity. These foods therefore require an upgrade through improved fermentation processes. This work determined the phenotypic characteristics of the fermenting microorganisms and microbial ecological succession during fermentation of cassava and maize to determine the predominant fermenting microorganisms. Cassava roots and maize grains were fermented using the traditional method of processing them into fufu and ogi for 72 h and 48 h respectively. Samples were drawn every 12 h for analysis. Enumeration and characterization of lactic acid bacteria were carried out on MRS medium with subsequent microscopic examination, physiological, biochemical reaction tests and API 50 CH gallery. Yeast isolates were identified by their morphological characteristics. Thirteen lactic acid bacteria were isolated from the fermenting cassava and 6 from the fermenting maize. The Isolates were Gram positive and catalase negative. Lactobacillus plantarum, L. fermentum and L. pentusus predominated in both fermentations while Candida tropicalis, C. krusei and Saccharomyces cerevisae also predominated in both fermentations. Candida inconspicuo was found only in cassava fermentation. The results of this work revealed the microbial ecology of fermented cassava and maize which is a prerequisite to the understanding needed to develop a multifunctional starter culture for these fermentations for their upgrade. Keywords: Cassava, Maize, Fermentation, lactic acid bacteria, Yeasts.


2021 ◽  
Vol 6 (2) ◽  
pp. 273-283
Author(s):  
Siti Nur Azizah ◽  
Mikhania Christiningtyas Eryani ◽  
Azizah Azizah

Probiotics are microbes in fermented foods that have beneficial effects on health. Microbes that act as probiotics are lactic acid bacteria (LAB) that can produce metabolites such as lactic acid, hydrogen peroxide, and bacteriocins. This study aimed to obtain lactic acid bacterial isolates from tape and tempeh, and to test the potential of LAB as a probiotic candidate by activity test as an antidiarrhea and its resistance to gastric pH and bile salts. The fermentation products used as a source of LAB isolates are tempeh sumber mas merk, and yellow cassava tape, sari madu merk from Jember. The results of the first stage regarding the isolation of LAB using GYP media showed that there were 2 LAB isolates (TaJ.14 and TaJ.15) from the tape and 4 LAB isolates (TeJ.18, TeJ.22, TeJ.24, and TeJ.25) from tempeh. The results of the antidiarrheal test using the disc diffusion method (oxoid) showed that TaJ.14 and TaJ.15 isolates were able to inhibit Bacillus subtilis, Escherichia coli, and Shigella dysentriae, while TeJ.18, TeJ.22, TeJ.24, TeJ.25, and Lactobacillus casei (control) was only able to inhibit B. subtilis and E. coli. The results of LAB resistance to gastric pH showed that the TeJ.25 isolate had the highest percentage of pH 3 and 2.5 resistance (51.13 and 33.03%) compared to other isolates and controls. LAB resistance test results against bile salts (oxgal) showed that the TeJ.22 isolate had the highest percentage of resistance (75.10%) compared to other isolates although was still higher in control (75.99%).


2020 ◽  
Vol 13 (1) ◽  
pp. 118-130
Author(s):  
É. Laslo ◽  
É. György ◽  
Cs. D. András

Abstract Acidification in lactic-fermented foods is realized by lactic acid bacteria as an added starter culture or by autochthonous strains. These microbial strains possess different prominent features that define the technological, organoleptic, nutritional, and microbial safety aspects of the product. The bioprotective effect of the bacterial strains may be related to antagonistic properties against food spoilage and/or pathogenic strains. The aim of the present study is to determine the antimicrobial properties of three different food-grade lactic acid bacteria in order to use them as bioprotective cultures. Our findings show that the Lactobacillus pentosus, Enterococcus faecalis, and Pediococcus parvulus exerted a bacteriostatic effect on Escherichia coli and Bacillus cereus, whereas the Saccharomyces cerevisiae growth was not inhibited, which made them susceptible agent for co-culture systems.


2020 ◽  
Author(s):  
◽  
Mellisa Nokulunga Jula

Cereal fermented products are popular in developing countries, especially in Asia and Africa, because of their unique taste and fulfilment. Throughout the years, they have played a vital part in bringing up infants as part of their weaning foods and contributing to the daily diet of many households. Food fortification and supplementation of cereal grains with inexpensive readily available legumes, which have higher protein content compared to cereals may lead to a potential decrease in protein-energy malnutrition. Underutilised and indigenous crops such as Bambara groundnut can be in incorporated into the fermentation of cereal fermented foods, such as injera. In this study, injera was prepared by substituting only 9% and 12% Bambara groundnut flour and comparing them with the traditionally fermented original control, which is injera made from only tef flour. The first part of the study was to identify and characterise the lactic acid bacteria (LAB) and yeast involved in the spontaneous fermentation of traditional tef-injera and the newly developed injera fortified with Bambara groundnut (which contains 12% Bambara groundnuts) at different fermentation intervals of 0, 24, 48, and 72 hour. A total of 70 LAB isolates and 30 yeast isolates were identified from both fermentations using rep-PCR fingerprinting followed by sequencing the 16S rRNA gene and the D1/D2 region of the 26S rRNA gene. Weissella confusa, Lc. lactis and Lb. curvatus predominated in both fermentations at different intervals of the fermentation. The second part of the study investigated the effectiveness of the isolated LAB starter cultures on the production of injera and injera fortified with Bambara groundnut after which their physicochemical properties were evaluated. There was a significant increase (p<0.05) in titratable acidity and a significant decrease in pH to below four within 24 hours; recorded for samples inoculated with LAB starter cultures when compared to samples fermented without inoculation. The third and fourth parts of the study investigated the proximate composition and storage stability of the injera samples. Injera fortified with 12% Bambara groundnut + LAB culture had a significantly high (p<0.05) protein of 23.21%, the lowest protein content being Tef injera at 7.35%. The protein digestibility of Tef injera increased with the addition of Bambara groundnut and LAB starter culture. The digestibility of protein increased from 40% for Tef injera to 80% for injera fortified with 12% Bambara flour + LAB culture. There was no significant increase (p >0.05) in the amino acid content after the addition of Bambara flour + LAB cultures; the amino acid concentrations were slightly lower than the standard concentration recommended by the Food and Agricultural Organisation/World Health Organisation for adults. Injera samples fortified with Bambara groundnut flour and inoculated with lactic acid starter cultures were stable with microbial counts ranging from 4.42 log cfu/g to 4.68 log cfu/g for TPC at 4 ̊C, yeast and mould, coliforms and aerobic spore formers were not detected in all the samples from day 0 to day three upon storage. Higher counts had been perceived at room temperature ranging from 4.60 log cfu/g to 7.53 log cfu/g for moulds and 4.90 log cfu/g to 9.26 cfu/g for TPC; coliforms were detected in one tef injera only ranging from 4.48 log cfu/g to 6.16 log cfu/g and no detection of aerobic spore formers in all samples. Refrigeration temperatures effectively maintained the microbiological quality of injera for three days. The nutritional quality, distinctively the protein content increased with the addition of Bambara groundnut flour and through the use of lactic acid bacteria as a starter culture This will potentially pave the way for the commercialisation of injera in the industry with the use of LAB starter culture to ensure a fast and continuous supply of fresh injera that is in high demand.


Author(s):  
I. H. Abdulkarim ◽  
S. S. D. Mohammed ◽  
A. A. Orukotan

Bacteriocin genes are biosynthetic genes which encodes proteins involved in bacteriocin regulation, self-immunity, transport and modification. This research was aimed at identifying the gene for the synthesis of bacteriocin. Four strains of lactic acid bacteria previously isolated from fermented foods (Nono (N2), Ogi (O3), Dawadawa (D1 and D3) and Wara (W3) were identified using molecular technique and used to produce bacteriocin. The bacteriocin activity was assayed against some test bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella sp and methicillin resistant Staphylococcus aureus) using agar well diffusion method and the bacteriocin genes were identified using BAGEL3. The LAB identified were Lactobacillus fermentum O3, Leuconostoc mesenteroides N2, Weissella cibaria D1 and 2 strains of Lactobacillus plantarum D3 and W3. The entire identified LAB was able to produce bacteriocin. The antimicrobial activity showed varied inhibitory effects of the bacteriocins on the test bacteria. Bacteriocin from isolate O3 showed the highest inhibition zone 16mm on S. aureus. The identified gene for these bacteriocins were plnJK gene for Lactobacillus plantarum str WCFS1 and strain LZ95 (W3 and D3), entA gene for Lactobacillus fermentum str 3872 (O3) and ppnC7 gene for Leuconostoc mesenteroides str SRA3 (N2) with the interaction of other peptides were responsible for bacteriocin production.


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