The Potential of Wood Vinegar to Replace Antimicrobials Used in Animal Husbandry-A Review.

The indiscriminate use of antimicrobials in animal husbandry can result in various types of environmental contamination. Part of the dose of these products is excreted, still active, in the animals' feces and urine. These excreta are widely used as organic fertilizers, which results in contamination with antimicrobial molecules. The impacts can occur in several compartments, such as soil, groundwater, and surface watercourses. Also, contamination by antimicrobials fed or administrated to pigs, chickens, and cattle can reach the meat, milk, and other animal products, which calls into question the sustainability of using these products as part of eco-friendly practices. Therefore, a search for alternative natural products is required to replace the conventional antimicrobials currently used in animal husbandry, aiming to mitigate environmental contamination. We thus carried out a review addressing this issue, highlighting wood vinegar (WV), also known as pyroligneous acid, as an alternative antimicrobial with good potential to replace conventional products. In this regard, many studies have demonstrated that WV is a promising product. WV is a nontoxic additive widely employed in the food industry to impart a smoked flavor to foods. Studies have shown that, depending on the WV concentration, good results can be achieved using it as an antimicrobial against pathogenic bacteria and fungi and a valuable growth promoter for poultry and pigs.

Antimicrobial activity and chemical profile of wood vinegar from eucalyptus (Eucalyptus urophylla x Eucalyptus grandis - clone I144) and bamboo (Bambusa vulgaris).

Microbial resistance to drugs is a public health problem; therefore, there is a search for alternatives to replace conventional products with natural agents. One of the potential antimicrobial agents is wood vinegar derived from the carbonization of lignocellulosic raw materials. The objectives of the present work were to evaluate the antibacterial and antifungal action of two kinds of wood vinegar (WV), one of Eucalyptus urograndis wood and another of Bambusa vulgaris biomass, and determine their chemical profile. The antimicrobial effect was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella enteritidis, Escherichia coli, Streptococcus agalactiae, and Candida albicans. The minimum inhibitory concentration and the minimum bactericidal and fungicidal concentrations were determined. Micrographs of the microorganisms before and after exposure to both kinds of wood vinegar were obtained by scanning electron microscopy. The chemical profile of the eucalyptus and bamboo vinegar was carried out by gas chromatography and mass spectrometry (GC/MS). Both types of WV presented significant antimicrobial activity, with the bamboo one having a higher efficiency. Both studied pyroligneous extracts seem promising for developing natural antimicrobials due to their efficiency against pathogens. GC/MS analyses demonstrated that the chemical profiles of both kinds of WV were similar but with some significant differences. The major component of the eucalyptus vinegar was furfural (17.2%), while the bamboo WV was phenol (15.3%). Several compounds in both WVs have proven antimicrobial activity, such as acetic acid, furfural, phenol, cresols, guaiacol, and xylenols. Together, they are the major in the chemical composition of the organic fraction of both WVs. Bamboo vinegar had a more expressive content of organic acids. Micrographs of microorganisms taken after exposure to both kinds of wood vinegar displayed several cell modifications. The potential of both types of wood vinegar as a basis for natural antimicrobial products seems feasible due to their proven effect on inhibiting the microorganisms' growth assessed in this experiment.

Use of a product based on wood vinegar of Eucalyptus clone I144 used in the control of bovine mastitis.

Bovine mastitis is one of the most frequent diseases in dairy cattle worldwide. The use of antiseptics in milking, if properly used, can lead to a reduction in potentially pathogenic microorganisms and their transmission between herds. Several medicinal plants have antiseptic potential, including eucalyptus (Eucalyptus spp.). Therefore, the objective of this study was to evaluate the effectiveness of wood vinegar from Eucalyptus urograndis clone GG I144 (EU) as an antiseptic in vitro and in vivo; in addition, to its cytotoxicity and antimicrobial resistance. Fifteen bovines were used, lactating females 3-6 years of age and divided into three groups of five animals each. The wood vinegar was placed in the teats of the animal for 28 days and collections of cellular debris were performed every 7 days. At the Veterinary Microbiology Laboratory (LAMIV) of UFERSA, the samples were processed and serial dilution was performed in Petri plates with plate count agar (PCA) at 37 °C. Cytotoxicity was verified based on morphological alterations and metabolic activity. Morphological changes were not observed in all cells incubated with 1 % pyroligneous extract. The in vitro data demonstrated antimicrobial activity against S. aureus, S. agalactiae, Salmonella, E. coli and P. aeruginosa. The bacteria of the genus Staphylococcus and Corynebacterium were resistant to penicillin (PEN), rifampicin (RIF), nitrofurantoin (NIT), erythromycin (ERI), and ciprofloxacin (CIP). The extract was used in vivo in the post-dipping of dairy cows, which reduced the microbiological load present in the mammary glands from 4.74 to 2.54 CFU, indicating its future use as an antiseptic.