Heterologous expression of pediocin PA-1 in Pichia pastoris: cloning, expression, characterization, and application in pork bologna preservation.

OBJECTIVE: Pediocin PA-1, an antimicrobial peptide derived from Pediococcus acidilactici PAC1.0, has a potential application as a food preservative thanks to its strong inhibitory activity against the foodborne pathogen L. monocytogenes. This study aimed to produce Pediocin PA-1 from the yeast P. pastoris and evaluate its characteristics. METHODS: Gene encoding Pediocin PA-1 was integrated into P. pastoris X33 genome to establish the strain X33::ped, which could produce and secrete this peptide into culture medium. The antimicrobial activity of Pediocin PA-1 was examined using agar diffusion assay. The stability of pediocin PA-1 was determined based on its remaining antibacterial activity after exposure to proteases and extreme pH and temperatures. The potential use of this bacteriocin in food preservation was demonstrated using the L. monocytogenes infected pork bologna. The anticancer activity of Pediocin PA-1 was also investigated on some cancer cells using MTT assay. RESULTS: We established the yeast P. pastoris X33::ped capable of producing pediocin PA-1 with antimicrobial activity against L. monocytogenes and some other harmful bacteria. Pediocin PA-1 was stable at 100˚C and resistant against pH 1-12 for 1 h, but susceptible to trypsin, α-chymotrypsin, and proteinase K. This peptide could reduce the number of L. monocytogenes in pork bologna by 3.59 log CFU/g after 7 days of storage at 4˚C. Finally, Pediocin PA-1 (25 µg/ml) inhibited the proliferation of A549 and Hela cancer cells. CONCLUSION: We succeeded in producing active Pediocin PA-1 from P. pastoris and demonstrated its potential use in food preservation and pharmaceutical industry.

Orange juice containing Pediococcus acidilactici CE51 modulates the intestinal microbiota and reduces induced inflammation in a murine model of colitis.

The management of inflammatory bowel diseases has been widely investigated, especially ulcerative colitis. Thus, studies with the application of new probiotic products are needed in the prevention/treatment of these clinical conditions. The objective of this work was to evaluate the effects of probiotic orange juice containing Pediococcus acidilactici CE51 in a murine model of colitis. 45 male Swiss lineage mice were used, divided into five groups (n = 9): control, colitis, colitis + probiotic (probiotic orange juice containing CE51), colitis + placebo (orange juice) and colitis + sulfasalazine (10 mg/kg/Weight). The induction of colitis was performed with dextran sodium sulfate (3%). The treatment time was 5 and 15 days after induction. Histopathological analysis, serum measurements of TNF-α and C-reactive protein and metagenomic analysis of feces were performed after euthanasia. Probiotic treatment reduced inflammation in the small intestine, large intestine and spleen. The probiotic did not alter the serum dosages of TNF-α and C-reactive protein. Their use maintained the quantitative ratio of the phylum Firmicutes/Bacteroidetes and increased Lactobacillus helveticus with 15 days of treatment (p < 0.05). The probiotic orange juice containing P. acidilactici CE51 positively modulated the gut microbiota composition and attenuated the inflammation induced in colitis.

Co-culturing fructophilic lactic acid bacteria and yeast enhanced sugar metabolism and aroma formation during cocoa beans fermentation.

Glucose and fructose are the main fermentable sugars in cocoa pulp. During fermentation, glucose is consumed within 48-72 h and fructose only after 120 h, mainly associated with the preferential use of glucose by microorganisms. In the first stage of this study, the complete genome sequence of a lactic acid bacterium with high fructose consumption capacity (Lactobacillus plantarum LPBF35) was reported. The notable genomic features of L. plantarum LPBF35 were the presence of alcohol/acetaldehyde dehydrogenase gene and improved PTS system, confirming its classification as a "facultatively" fructophilic bacterium. Subsequently, this bacterium was introduced into cocoa fermentation process in single and mixed cultures with Pediococcus acidilactici LPBF66 or Pichia fermentans YC5.2. Community composition by Illumina-based amplicon sequencing and viable counts indicated suppression of wild microflora in all treatments. At the beginning of the fermentation processes, cocoa pulp consisted of approximately 73.09 mg/g glucose and 73.64 mg/g fructose. The L. plantarum LPBF35 + P. fermentans YC5.2 process showed the lowest levels of residual sugars after 72 h of fermentation (7.89 and 4.23 mg/g, for fructose and glucose, respectively), followed by L. plantarum LPBF35 + Ped. acidilactici LPBF66 (8.85 and 6.42 mg/g, for fructose and glucose, respectively), single L. plantarum LPBF35 treatment (4.15 and 10.15 mg/g, for fructose and glucose, respectively), and spontaneous process (22.25 and 14.60 mg/g, for fructose and glucose, respectively). The positive interaction between L. plantarum LPBF35 and P. fermentans YC5.2 resulted in an improved formation of primary (ethanol, lactic acid, and acetic acid) and secondary (2-methyl-1-butanol, isoamyl acetate, and ethyl acetate) metabolites during fermentation. The primary metabolites accumulated significantly in cocoa beans fermented by P. fermentans YC5.2 + L. plantarum LPBF35, causing important reactions of color development and key flavor molecules formation. The results of this study suggest that fructophilic lactic acid bacteria and yeast is a microbial consortium that could improve sugar metabolism and aroma formation during cocoa beans fermentation.

Fermentation and aerobic stability of rehydrated corn grain silage treated with different doses of Lactobacillus buchneri or a combination of Lactobacillus plantarum and Pediococcus acidilactici.

We investigated the effects of different types and doses of inoculants for ensiling rehydrated corn grain. Shelled corn was finely ground and rehydrated to 35% moisture. Treatments were as follows: (1) control (no additives); (2) Lactobacillus plantarum and Pediococcus acidilactici (LPPA) at a theoretical application rate of 1 × 105 cfu/g; (3) LPPA at 5 × 105 cfu/g; (4) LPPA at 1 × 106 cfu/g; (5) Lactobacillus buchneri (LB) at 1 × 105 cfu/g; (6) LB at 5 × 105 cfu/g; and (7) LB at 1 × 106 cfu/g. We detected no effect of inoculant dose. Gas losses were greater in silages treated with LB compared with control and LPPA silages. Treating silages with LB reduced the concentrations of lactic acid and ethanol and increased silage pH and concentrations of acetic acid, propionic acid, and 1,2-propanediol. At silo opening, silages treated with LB had higher counts of lactic acid bacteria but lower yeast counts than the control silage. Aerobic stability was greater for silages treated with LB and lower for silages treated with LPPA compared with the control. The LB reduced dry matter (DM) losses during aerobic exposure, whereas LPPA increased them. Prolamin content was lower in silages treated with LB compared with the control, resulting in greater ruminal in situ DM degradability. Inoculating LB to a dose of 1 × 105 cfu/g increased aerobic stability and ruminal in situ DM degradability of rehydrated corn grain silage. The addition of LPPA did not alter the fermentation process and worsened the aerobic stability of rehydrated corn grain silage. Further studies are warranted to confirm these conclusions in other corn hybrids, inoculants, and their combinations.

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.

Whole genome sequence of lactic acid bacterium Pediococcus acidilactici strain S1.

Pediococcus acidilactici strain S1, a lactic acid-fermenting bacterium, was isolated from makgeolli-a Korean traditional fermented alcoholic beverage. Here we report the 1,980,172bp (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.

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

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 1,991,399bp (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.

Partial Characterization of Bacteriocin Produced by Halotolerant Pediococcus acidilactici Strain QC38 Isolated from Traditional Cotija Cheese.

During a screening of lactic acid bacteria producing bacteriocin from Cotija cheese, the strain QC38 was isolated. Based on the 16S rRNA gene nucleotide sequencing (516 pb accession no KJ210322) and phylogenetic analysis, the isolate was identified as Pediococcus acidilactici. Neutralized cell-free supernatant was tested for antimicrobial activity against 17 Gram-negative and Gram-positive pathogens. Growth inhibition was achieved against Listeria monocytogenes (supplier or indication or source), Staphylococcus aureus, Vibrio vulnificus, Vibrio cholerae O1 Ogawa, Vibrio cholerae NO 01 and Salmonella enterica subsp. Enterica serovar Typhimurium. Bacteriocin-like substance, after heating at 121°C for 15 min it remained stable and its antimicrobial activity was observed at pH ranging from 1.0 to 10.0 but inactivated by α-chymotrypsin and proteinase K. Strain QC38 was able to grow in 1-9% NaCl concentration. The plate overlay assay showed an approximate size of bacteriocin-like substance between 3.4 and 6.5 kDa. P. acidilactici QC38 harboured a plasmid that contains a gene for a pediocin (PA-1).