Antibacterial and antimycobacterial activity of white shrimp (Litopenaeus vannamei) exoskeleton and cephalothorax by-products extracts: fatty acids profile of the active hexanic shrimp cephalothorax extract

The objective of this study was to evaluate the antibacterial and antimycobacterial potential of the by-products of white shrimp (Litopenaeus vannamei). Sonora, México is the second shrimp producer state. The following extracts were obtained: exoskeleton hexanic, methanolic and acqueous extracts (ExHex, ExMe, ExAc); and cephalothorax hexanic, acetonic and methanolic extracts (CeHex, CeAce, CeMe). Antibacterial effect was determined by the broth microdilution method against Gram-positive bacteria: Enterococcus faecalis American Type Culture Collection (ATCC) 51299, Staphylococcus aureus ATCC 25293, and Staphylococcus epidermidis; Gram-negative bacteria: Escherichia coli ATCC 25922, Klebsiella pneumoniae, Pseudomonas aeruginosa ATCC 10145, and Salmonella typhimurium; and Mycobacterium bovis bacillus Calmette-Guérin (M. bovis BCG) Danish strain. CeHex resulted active against all Gram-positive and Gram-negative bacteria (MIC50= 400 ug mL-1) and against M. bovis BCG (MIC100= 250 ug mL-1). Gas chromatography (GC) of CeHex identified oleic, linoleic, palmitic, stearic, behenic, palmitoleic and linolenic fatty acids. The strong antibacterial activity of CeHex and the identification of its main chemical constituents justify further studies on the clinical applications of this marine by-product.