Antibacterial activity of Lactobacillus plantarum BS25, Pediococcus acidilactici S3 crude, and partially-purified cell-free supernatants against methicillinsusceptible and methicillin-resistant Staphylococcus aureus strains

Background@#The rising public health threat brought about by antibiotic resistance, such as of Staphylococcus aureus, opened doors of opportunities for natural products research to explore novel antimicrobial agents. @*Objective@#This study aimed to determine the antimicrobial activity of cell-free supernatants from Lactobacillus plantarum BS25 and Pediococcus acidilactici S3 against Staphylococcus aureus (ATCC# 25923) and methicillin-resistant S. aureus (ATCC# 33591). @*Methodology@#Cell-free supernatants (CFS) of Lactobacillus plantarum BS25 and Pediococcus acidilactici S3, isolated from fermented rice-fish mixture balao-balao and fermented spicy sausage longganisa, respectively, were tested against methicillin-susceptible (MSSA, ATCC 25923) and methicillin-resistant (MRSA, ATCC 33591) Staphylococcus aureus strains for antibacterial activity using the resazurin assay. @*Results@#Both BS25 and S3 CFS showed high activities against MSSA and partial inhibition against MRSA. Proteinaceous components of the CFS were extracted using ammonium sulfate precipitation with BS25 and S3 exhibited low activities against MSSA but partial inhibition was observed against MRSA. Other small molecules were extracted from the CFS through liquid-liquid extraction using ethyl acetate and tested in 100, 250, 500, 750, and 1000 ppm concentrations. The 1000-ppm concentrations of the BS25 and S3 ethyl acetate extracts achieved the highest antibacterial activity against MSSA and MRSA. @*Conclusion@#This study showed that the crude cell-free supernatants, ammonium sulfate precipitates, and ethyl acetate extracts of BS25 and S3 CFS exhibited potential in inhibiting Gram-positive MSSA and MRSA. However, the partially-purified samples require relatively high concentrations in order to produce significant inhibition activities and therefore require further purification.

Probiotic potential of lactic acid bacteria isolated from Vietnamese sour-fermented fish product

Aims@#To isolate and characterize the lactic acid bacteria (LAB) strains from the “mam chua ca ro” (sour fermented fish) in the South of Vietnam and investigate their potential anti-bacterial properties.@*Methodology and results@#Four LAB strains (MCR1, MCR2, MCR3 and MCR4) were isolated from the "mam chua ca ro" product and their anti-bacterial activity was determined using the spot assay and the paper disc diffusion method. The isolated LABs can inhibit Escherichia coli ATCC 25922, Staphyloccocus aureus ATCC 25923 and Vibrio parahaemolyticus BV016 and produce bacteriocin to control the growth of E. coli ATCC 25922 and S. aureus ATCC 25923, except V. parahaemolyticus. MCR2 was chosen to sequence 16S rRNA of Pediococcus acidilactic.@*Conclusion, significance and impact of study@#On the basis of their prominent anti-pathogenic bacteria activity, LAB strains isolated from Vietnamese sour-fermented fish products were verified as prospective probiotics.

Whole genome sequence of lactic acid bacterium Pediococcus acidilactici strain S1

Abstract Pediococcus acidilactici strain S1, a lactic acid-fermenting bacterium, was isolated from makgeolli-a Korean traditional fermented alcoholic beverage. Here we report the 1,980,172 bp (G + C content, 42%) genome sequence of Pediococcus acidilactici strain S1 with 1,525 protein-coding sequences (CDS), of which 47% could be assigned to recognized functional genes. The genome sequence of the strain S1 might provide insights into the genetic basis of the lactic acid bacterium with alcohol-tolerant.

Draft genome sequence of alcohol-tolerant bacteria Pediococcus acidilactici strain K3

Abstract Pediococcus acidilactici strain K3 is an alcohol-tolerant lactic acid bacterium isolated from nuruk, which is a traditional Korean fermentation starter for makgeolli brewing. Draft genome of this strain was approximately 1,991,399 bp (G+C content, 42.1%) with 1525 protein-coding sequences (CDS), of which 44% were assigned to recognized functional genes. This draft genome sequence data of the strain K3 will provide insights into the genetic basis of its alcohol-tolerance.