Comparative Study on the in vitro Antibacterial Efficacy of Aqueous and Methanolic Extracts of Quercus infectoria Gall`s Against Cellulosimicrobium cellulans

Biodegradation of biodiesel-oil by Cellulosimicrobium sp. Isolated from Colombian Caribbean soils

Biodiesel is considered to be a natural substitute for fossil fuel. The comparatively low toxicity of biodiesel and its susceptibility to microbial biodegradation could reduce its environmental impact. Currently, biodiesel is sold previously mixed with petroleum-based hydrocarbons. The aim of this work was to measure the biodegradation potential of commercially available biodiesel, using bacterial strains (BBCOL-001, BBCOL-002, and BBCOL-003) isolated from a tropical forest soils in the Colombian Caribbean. According to nucleotide sequencing of the gene encoding for 16S rRNA, the strains belong to members of the genus Cellulosimicrobium. GC-MS analysis showed that biodiesel-oil alkanes were degraded by an average of 81.5% with optical density reaching 0.2-0.3 in minimal salt media at 37°C for 5 days. Individual diesel-oil alkanes were degraded by the strains at rates between 64.9% to 100%. The increase in bacterial biomass confirmed the use of the substrates by the microorganisms, suggesting these hydrocarbons are a carbon source. Changes in the biochemical behaviour of the strains suggested their capacity to adapt to environmental conditions might be an important resource for bioremediation.

Application of Quercus infectoria extract as a natural antimicrobial agent for chicken egg decontamination

Egg contamination with microbial pathogens is an enduring worldwide concern. Natural products are frequently recommended as ideal alternatives to substitute synthetic and chemical antimicrobials. Oak galls (Quercus infectoria) are aberrant growths on oak trees that have many medicinal and pharmaceutical applications. Q. infectoria extract (QIE) antimicrobial action was assessed against many microbial species, and used for eggshell decontamination. QIE antimicrobial activity was evidenced against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium and Candida albicans, using different assay methods. Disinfection of eggshell microbial contamination, by immersion in 1% QIE solution, sharply reduced total colony count, yeasts and molds, Enterobacteriaceae. E. coli and S. aureus were completely inhibited after 60min of immersion in QIE. QIE biochemical analysis revealed elevated contents of phenolic and flavonoid compounds. The captured micrographs of S. aureus cells treated with QIE showed strong alterations in cell morphology; cells were entirely lysed and ruptured after 6h of treatment. QIE can be recommended as an effective and natural disinfectant for decontaminating eggshells from pathogenic microorganisms.