Partial Purification and Characterization of Bacteriocin-Like Inhibitory Substances Produced by Streptomyces sp. Isolated from the Gut of Chanos chanos

Abstract

Bacteriocin-like inhibitory substances (BLIS) have sparked great interest because of their promising use in food as natural antimicrobial agents. In this work, six Streptomyces isolates obtained from the gut of Chanos chanos demonstrated their ability to produce extracellular metabolites with inhibitory activity against Salmonella enterica serovar Typhimurium, Escherichia coli, Listeria monocytogenes, and Staphylococcus aureus. Exposure of the extracellular metabolites to proteolytic enzymes (i.e., proteinase-K, trypsin, and pepsin) revealed high sensitivity and confirmed their proteinaceous nature. The metabolites were stable at high temperatures (up to 100°C for 30 min) and a wide range of pH (pH 2.0–7.0). Fractionation of the crude BLIS by filtration yielded three fractions based on molecular weight: <3 kDa, 3–10 kDa, and >10 kDa. Analysis of the antibacterial activity of these fractions showed increased specific activity, especially in the fraction with a molecular weight (MW) of <3 kDa, relative to the crude sample. The fraction with MW < 3 kDa had minimum inhibitory and bactericidal concentrations in ranges 0.04–0.62 mg·mL−1 and 0.08–1.25 mg·mL−1, respectively. This fraction also showed better temperature and pH stability compared with crude BLIS. Brine shrimp toxicity assay revealed that this fraction has moderate toxicity with a 50% lethal concentration of 226.975 μg·mL−1 (i.e., moderate toxicity) to Artemia salina. Identification of the peptide sequences of this fraction by liquid chromatography–tandem mass spectrometry yielded 130 proteins with retention times of 15.21–19.57 min. Eleven proteins with MWs of 1345.66–2908.35 Da and composed of less than 30 amino acid residues with high hydrophobicity (15.34–26.22 kcal·mol−1) appeared to be responsible for the antibacterial activity of the fraction. This study revealed the potential application of BLIS from Streptomyces, especially BLIS SCA-8, as antibacterial agents.

Isolation, Characterization, and Effect on Biofilm Formation of Bacteriocin Produced by Lactococcus lactis F01 Isolated from Cyprinus carpio and Application for Biopreservation of Fish Sausage

“…However, the slight increase of the load 2 h after the introduction of the bacteriocin is due to the decrease of the bacteriocin concentration in the medium; this decrease can be linked to the action of the proteolytic enzymes synthesized by the strain or bacteriocin titration. Similar results have been obtained by [43][44][45].…”

Purification, HR-LC-ESI-MS-MS Identification, and Peptide Prediction of Bacteriocin-Like Inhibitory Substances Produced by Streptomyces sp. Isolated from Chanos chanos

“…Antibacterial activity and protein analysis showed that BLIS with MW <3 and 3-10 kDa were the most potent fractions because they had the highest BLIS-specific activity. Potential fractions also showed their sensitivity to proteolytic enzymes (proteinase-K, trypsin, and pepsin) [ 18 ]. The fraction was further fractionated by gel filtration chromatography to obtain semi-purified BLIS.…”

“…BLIS produced by six Streptomyces isolated from the gut of Chanos chanos: S. variabilis SCA5 (S5), S. variabilis SCA11 (S11), S. variabilis AIA10 (A10), S. labedae SCA8 (S8), S. globisporus AIA12 (A12) and S. misionensis AIA17 (A17) [15][16][17] with the method and culture conditions according to Kurnianto et al [18]. BLIS in freeze-dried form dissolved in distilled water.…”

Marine Actinobacteria a New Source of Antibacterial Metabolites to Treat Acne Vulgaris Disease—A Systematic Literature Review

“…This solvent is described as the ideal solvent for obtaining metabolites with antibacterial activity. This may be because it is possible that actinobacteria, especially streptomyces, produce semipolar antibacterial compounds so that they can be extracted by solvents with the same polarity as ethyl acetate, as mentioned in the study by Kurnianto et al [ 180 ]. Likewise, Satish et al evaluated the activity of extracts obtained from different solvents such as chloroform, butanol, and ethyl acetate against MRSA, finding that only the extracts obtained with the latter exhibited antibacterial activity [ 87 ].…”