Out of six samples of wastewater produced in the dairy industry, taken in 2017 at various places of dairy operations, 86 bacterial strains showing decarboxylase activity were isolated. From the wastewater samples, the species of genera Staphylococcus, Lactococcus, Enterococcus, Microbacterium, Kocuria, Acinetobacter, Pseudomonas, Aeromonas, Klebsiella and Enterobacter were identified by the MALDI-TOF MS and biochemical methods. The in vitro produced quantity of eight biogenic amines (BAs) was detected by the HPLC/UV-Vis method. All the isolated bacteria were able to produce four to eight BAs. Tyramine, putrescine and cadaverine belonged to the most frequently produced BAs. Of the isolated bacteria, 41% were able to produce BAs in amounts >100 mg L-1. Therefore, wastewater embodies a potential vector of transmission of decarboxylase positive microorganisms, which should be taken into consideration in hazard analyses within foodstuff safety control. The parameters of this wastewater (contents of nitrites, nitrates, phosphates, and proteins) were also monitored.
- MeSH
- Acinetobacter MeSH
- Aeromonas MeSH
- Biogenic Amines chemistry MeSH
- Water Pollutants, Chemical chemistry isolation & purification MeSH
- Enterobacter MeSH
- Enterococcus MeSH
- Carboxy-Lyases chemistry MeSH
- Klebsiella MeSH
- Lactobacillus MeSH
- Lactococcus MeSH
- Microbacterium MeSH
- Water Microbiology MeSH
- Dairying * MeSH
- Wastewater analysis microbiology MeSH
- Pediococcus MeSH
- Pseudomonas MeSH
- Spectrophotometry, Ultraviolet MeSH
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization MeSH
- Staphylococcus MeSH
- Streptococcus MeSH
- Chromatography, High Pressure Liquid MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Pediococcus pentosaceus GS4 (MTCC 12683), a probiotic lactic acid bacterium (LAB), was found to produce bacteriocin in spent culture. Antibacterial and antagonistic potential of this bacteriocin against reference strains of Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 25619), and Listeria monocytogenes (ATCC 15313) was proven by double-layer and well diffusion methods wherein nisin and ampicillin were used as positive controls. Bacteriocin in supernatant was purified and analyzed by SDS-PAGE, RP-HPLC, and circular dichroism (CD). The physico-chemical properties of purified bacteriocin were characterized being treated at different temperatures (30 to 110 °C), pH (3.0 to 12.0), with different enzymes (α-amylase, pepsin, and lysozyme), and organic solvents (hexane, ethanol, methanol, and acetone) respectively. The molar mass of bacteriocin (named pediocin GS4) was determined as 9.57 kDa. The single peak appears at the retention time of 2.403 with area amounting to 25.02% with nisin as positive control in RP-HPLC. CD analysis reveals that the compound appears to have the helix ratio of 40.2% with no beta sheet. The antibacterial activity of pediocin GS4 was optimum at 50 °C and at pH 5.0 and 7.0. The pediocin GS4 was not denatured by the treatment of amylase and lysozyme but was not active in the presence of organic solvents. This novel bacteriocin thus m ay be useful in food and health care industry.
- MeSH
- Anti-Bacterial Agents chemistry isolation & purification pharmacology MeSH
- Bacteria drug effects MeSH
- Hydrolases metabolism MeSH
- Hydrogen-Ion Concentration MeSH
- Molecular Weight MeSH
- Nisin chemistry MeSH
- Pediocins chemistry isolation & purification pharmacology MeSH
- Pediococcus pentosaceus chemistry metabolism MeSH
- Probiotics * MeSH
- Solvents MeSH
- Protein Structure, Secondary MeSH
- Protein Stability MeSH
- Temperature MeSH
- Publication type
- Journal Article MeSH
Fungi are commonly involved in dairy product spoilage and the use of bioprotective cultures can be a complementary approach to reduce food waste and economic losses. In this study, the antifungal activity of 89 Lactobacillus and 23 Pediococcus spp. isolates against three spoilage species, e.g., Yarrowia lipolytica, Rhodotorula mucilaginosa and Penicillium brevicompactum, was first evaluated in milk agar. None of the tested pediococci showed antifungal activity while 3, 23 and 43 lactobacilli isolates showed strong antifungal activity or total inhibition against Y. lipolytica, R. mucilaginosa and P. brevicompactum, respectively. Then, the three most promising strains, Lactobacillus paracasei SYR90, Lactobacillus plantarum OVI9 and Lactobacillus rhamnosus BIOIII28 at initial concentrations of 105and 107CFU/ml were tested as bioprotective cultures against the same fungal targets in a yogurt model during a 5-week storage period at 10 °C. While limited effects were observed at 105CFU/ml inoculum level, L. paracasei SYR90 and L. rhamnosus BIOIII28 at 107CFU/ml respectively retarded the growth of R. mucilaginosa and P. brevicompactum as compared to a control without selected cultures. In contrast, growth of Y. lipolytica was only slightly affected. In conclusion, these selected strains may be good candidates for bioprotection of fermented dairy products.
- MeSH
- Antifungal Agents pharmacology MeSH
- Lactobacillus physiology MeSH
- Dairy Products microbiology MeSH
- Pediococcus physiology MeSH
- Penicillium growth & development MeSH
- Food Microbiology MeSH
- Probiotics MeSH
- Rhodotorula growth & development MeSH
- Yarrowia growth & development MeSH
- Publication type
- Journal Article MeSH
A large-scale screen of some 7,000 presumptive lactic acid bacteria (LAB), isolated from animal, human, or plant origin, identified 1,149 isolates with inhibitory activity against the food-spoilage mould Penicillium expansum. In excess of 500 LAB isolates were subsequently identified to produce a broad spectrum of activity against P. expansum, Penicillium digitatum, Penicillium notatum, Penicillium roqueforti, Rhizopus stolonifer, Fusarium culmorum, Aspergillus fumigatus and Rhodotorula mucilaginosa. Partial 16S rRNA sequencing of 94 broad spectrum isolates revealed that the majority of antifungal producers were strains of Lactobacillus plantarum. The remaining population was composed of Weissella confusa and Pediococcus pentosaceous isolates. Characterization of six selected broad-spectrum antifungal LAB isolates revealed that antifungal activity is maximal at a temperature of 30 °C, a pH of 4.0 and is stable across a variety of salt concentrations. The antifungal compound(s) was shown to be neither proteinaceous nor volatile in nature. P. pentosaceous 54 was shown to have protective properties against P. expansum spoilage when applied in pear, plum and grape models, therefore representing an excellent candidate for food-related applications.
- MeSH
- Antifungal Agents metabolism MeSH
- DNA, Bacterial chemistry genetics MeSH
- Fungi drug effects growth & development MeSH
- Hydrogen-Ion Concentration MeSH
- Food Preservation methods MeSH
- Lactobacillus plantarum classification genetics isolation & purification metabolism MeSH
- Microbial Interactions MeSH
- Fruit microbiology MeSH
- Pediococcus classification genetics isolation & purification metabolism MeSH
- Food Microbiology MeSH
- Pyrus microbiology MeSH
- DNA, Ribosomal chemistry genetics MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Prunus microbiology MeSH
- Temperature MeSH
- Vitis microbiology MeSH
- Weissella classification genetics isolation & purification metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
