scholarly journals Extracellular Proteolytic Activity and Amino Acid Production by Lactic Acid Bacteria Isolated from Malaysian Foods

2019 ◽  
Vol 20 (7) ◽  
pp. 1777 ◽  
Author(s):  
Cui Jin Toe ◽  
Hooi Ling Foo ◽  
Teck Chwen Loh ◽  
Rosfarizan Mohamad ◽  
Raha Abdul Rahim ◽  
...  

Amino acids (AAs) are vital elements for growth, reproduction, and maintenance of organisms. Current technology uses genetically engineered microorganisms for AAs production, which has urged the search for a safer food-grade AA producer strain. The extracellular proteolytic activities of lactic acid bacteria (LAB) can be a vital tool to hydrolyze extracellular protein molecules into free AAs, thereby exhibiting great potential for functional AA production. In this study, eight LAB isolated from Malaysian foods were determined for their extracellular proteolytic activities and their capability of producing AAs. All studied LAB exhibited versatile extracellular proteolytic activities from acidic to alkaline pH conditions. In comparison, Pediococcus pentosaceus UP-2 exhibited the highest ability to produce 15 AAs extracellularly, including aspartate, lysine, methionine, threonine, isoleucine, glutamate, proline, alanine, valine, leucine, tryptophan, tyrosine, serine, glycine, and cystine, followed by Pediococcus pentosaceus UL-2, Pediococcus acidilactici UB-6, and Pediococcus acidilactici UP-1 with 11 to 12 different AAs production detected extracellularly. Pediococcus pentosaceus UL-6 demonstrated the highest increment of proline production at 24 h of incubation. However, Pediococcus acidilactici UL-3 and Lactobacillus plantarum I-UL4 exhibited the greatest requirement for AA. The results of this study showed that different LAB possess different extracellular proteolytic activities and potentials as extracellular AA producers.

1991 ◽  
Vol 54 (5) ◽  
pp. 349-353 ◽  
Author(s):  
AMECHI OKEREKE ◽  
THOMAS J. MONTVILLE

Twenty-three strains of lactic acid bacteria were tested by deferred antagonism methods for bacteriocin-like activity against types A and B spores from 11 proteolytic and nonproteolytic Clostridium botulinum strains. Pediococcus pentosaceus ATCC 43200, Pediococcus pentosaceus ATCC 43201, Lactococcus lactis subsp. lactis ATCC 11454, Lactobacillus acidophilus N2, Lactobacillus plantarum Lb75, Lactobacillus plantarum Lb592, and Lactobacillus plantarum BN exhibited bacteriocin-like inhibition of all C. botulinum strains tested. By excluding inhibition due to hydrogen peroxide, acid, and lytic phage and confirming their proteinaceous nature, the inhibitors were confirmed as bacteriocins. The minimum inhibitory cell concentrations (MICC) required to produce 1 mm radius inhibition zones were determined by direct antagonism testing. Only strains 43200, 43201, 11454, and N2 were inhibitory when cultured simultaneously with the botulinal spores. The MICCs of strains antagonistic to C. botulinum spores by simultaneous testing ranged between 1.6 × 105and 4.7 × 107CFU/ml. Based on the MICCs, P. pentosaceus 43200 was most inhibitory to C. botulinum.


2017 ◽  
Vol 4 (2) ◽  
pp. 263
Author(s):  
Ida Ayu Ketut Ariningsih ◽  
Yan Ramona ◽  
Nyoman Semadi Antara

Candidacies in female reproductive tract are mainly caused by Candida albicans. This infection often causes serious problems, particularly on their reproductive tract (genital part). Until recently, control of this infection has relied on the use of antibiotics. However due to numerous bad side effects of antibiotics, lactic acid bacteria have been proposed as an alternative method to control the growth of Candida albicans. Therefore, this research was aimed to isolate, screen, and characterize lactic acid bacterial isolates (LAB) antagonistic against Candida albicans (the causative agent of candidacies infection in reproductive tract of human). LABs were isolated from various fermented foods, such as tape ketan and kimchi. Isolation of LABs was conducted by applying dilution and spread plate method on MRS agar medium supplemented with BCP indicator to distinguish LABs from non acid-producing bacteria. Colonies with indication to produce acid were screened for antagonistic activity against C. albicans on MRS agar and followed by characterization of those isolates (Gram stain, catalase production test, oxydase production, gas production test, resistance test to low pH conditions and to high level of NaDC (sodium deoxicolic), and test for ability to convert colic acid (CA) into deoxicolic acid (DCA)). The results showed that 46 LAB isolates were successfully isolated from samples of tape ketan and kimchi. Among those, 7 isolates showed antagonistic activity against C. albicans in in vitro tests. All these 7 candidates were also found to be resistance to low pH conditions (up to pH 2) and to high level of NaDC (up to 0.6 mM). Four most potential isolates were further testes for ability to convert colic acid into deoxycolic acid and none showed positive result, indicating that they all showed initial potential and safe for future human probiotic development (especially to be used to treat patients infected by C. albicans).


2017 ◽  
Vol 26 (1) ◽  
pp. 173-179 ◽  
Author(s):  
Suree Nanasombat ◽  
Patcharee Treebavonkusol ◽  
Sunisa Kittisrisopit ◽  
Thitirut Jaichalad ◽  
Saranya Phunpruch ◽  
...  

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.


2019 ◽  
Vol 34 (2) ◽  
pp. 83-90
Author(s):  
Farzana Ehetasum Hossain ◽  
Sharmin Akther ◽  
Atqiya Fahmida Tajalli

A significant limitation to flourish poultry industry in Bangladesh is the emergence of multidrug resistance pathogenic bacteria like Salmonella spp. due to uncontrolled use of antibiotics for disease treatment. An alternative to antibiotics could be the application of probiotics. About 120 cloacal-swabs from poultry birds were investigated, seventy two (72) isolates of Salmonella spp. and twenty two (22) isolates of lactic acid bacteria (out of 50)were identified respectively by cultural, morphological and biochemical tests presumptively. Antibiotic sensitivity test of Salmonella spp. was performed, followed by Kirby-Bauer disc-diffusion assay with six antibiotic groups. All those isolates of Salmonella spp. were found to be highly resistant to â-lactam, cephalosporin, tetracycline and macrolide, highly sensitive to carbapenem and moderately sensitive to aminoglycosides. Then Salmonella spp. were used as a target for the prospective probiotic bacteria which were screened based on antimicrobial activity against those multidrug resistance Salmonella spp. In antagonism assay such as disc diffusion and one-streak method, it was revealed that five lactic acid bacteria showed antimicrobial activity against Salmonella spp. Further, lactic acid bacteria were characterized based on their tolerance ability to pH and NaCl, antibiotic susceptibility test. The tolerance range of Lactic acid bacteria was about pH (3.5-9.5), NaCl (4-8) % and also resistant to antibiotics groups like B lactam, aminoglycosides, and quinolone. Then 16S rDNA gene sequence analysis was performed for molecular identification of potential probiotic bacteria. One representative isolate was identified as phylogenetically closed relative to Pediococcus acidilactici. This study was able to demonstrate that Pediococcus acidilactici as anindigenous probiotic candidate to inhibit the growth of isolated multidrug resistant Salmonella spp. in poultry. The potent probiotic candidate Pediococcus sp. could be used to counter bacterial diseases in poultry, thereby it could ensure food safety in the poultry industries of Bangladesh. Bangladesh J Microbiol, Volume 34 Number 2 December 2017, pp 83-90


1984 ◽  
Vol 47 (5) ◽  
pp. 354-358 ◽  
Author(s):  
M. RACCACH ◽  
E. C. HENNINGSEN

Growth of Yersinia enterocolitica 0:3 and 0:8 (103 CFU/g) in cured meat at 35°C was controlled (inhibition of 3.9 to 4.0 log10 CFU/g) by each one of the lactic acid bacteria (LAB) Pediococcus pentosaceus, Pediococcus acidilactici and Lactobacillus plantarum. The pH of the meat was reduced by LAB to 4.9 to 5.1. At 27°C, growth of Y. enterocolitica 0:3 and 0:8 (103 CFU/g) in cured meat was almost totally controlled with or without LAB. This inhibition of growth was observed with populations of Y. enterocolitica up to 106 CFU/g of meat. In plain meat (devoid of any additive) at 27°C, LAB inhibited (by 1.9 to 2.7 log10 CFU/g) the growth of Y. enterocolitica 0:3 and 0:8 (103 CFU/g). No change in pH of the meat was observed. Sodium chloride (3.0%) and sodium nitrite (156 mg/kg) were also observed to play an important role in the inhibition (2.3 to 3.6 log10 CFU/g) of growth of Y. enterocolitica 0:3 and 0:8. Sodium nitrite (156 mg/kg), at a concentration about 200 times lower than that of sodium chloride (3.0%), was as efficient an inhibitor to Y. enterocolitica as sodium chloride. Dextrose was slightly inhibitory to Y. enterocolitica 0:3 only. Spices, garlic powder and white pepper did not control the growth of either serotype of Y. enterocolitica. A temperature of 27°C in combination with either curing salts or LAB played an important role in controlling the growth of Y. enterocolitica in meat thus contributing to the safety of the product.


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