Evaluation of biocides for possible use in fuel tanks

Abstract

Biocides are the more worldwide used chemical compounds for the biodeterioration treatment, and they are
specific for different fuels. In this article it was evaluated the Biobor J.F. antimicrobial activity in vitro, the Liquid 1 and
six natural extracts (Quinidine trep, Quinidine, Colophony (2 mg/mL), VN (2.1 mg/mL), AR (2 mg/mL) and the extract
T2-CIIQ). Germs from the, Pseudomonas, Bacillus and Micrococcus and the fungus of the species Hormoconis resinae,
Aspergillus versicolor, Aspergillus niger and Alternaria alternate, isolated from contaminated fuels. The determination
of the minimum inhibitory concentration (MIC) was made by the radial diffusion method in monolayer of agarized atmosphere
and the minimum germicide concentration (MGC) and the minimum fungicide concentration (MFC) were
determined by the serial double dilutions method in culture with transfers to solid environment. The Biobor J.K. and
the Liquid I showed an inhibition microbial with the pure product. The germicide and fungicide activities were effective
only with the products which haven’t been diluted. The Quinidine treq and Quinidine extracts had a 12.5 μg/mL MIC for
both germs and fungus. The T2-CIIQ MIC has a value of 30 μg/mL coinciding with the MGC and the MFC. The Biobor J.F.
and the Liquid I showed an antimicrobial activity without dilute. The Quinidine and T2-CIIQ extracts offered germicide
and germistatic actions to low concentrations: 12.5 and 30 μg/mL respectively.