D-amino acids enhanced biocide mitigation of field biofilm consortia in lab testsYingchao Li (speaker) Fazlollah Madani Sani Weizhen Cai Tingyue GuDepartment of Chemical and Biomolecular EngineeringInstitute for Corrosion and Multiphase TechnologyOhio UniversityAthens Ohio 45701 USAMicrobiologically influenced corrosion (MIC) is a major problem in the oil and gas industry as well as many other industries. Current treatment methods rely mostly on pigging and biocide dosing. Because field systems are not sterile microbes always bound back which means treatment needs to be repeated in cycles. The application of the same biocide will selectively promote resistant microbes. Overtime biocide dosage keeps escalating leading to cost increase and environmental concerns. We have previously demonstrated that some D-amino acids are biocide enhancers. They are hypothesized to replace the D-alanine terminus that exists in all bacterial cell walls. Under a biocide stress these D-amino acids can disperse recalcitrant biofilms such as theDesulfovibrio vulgaris biofilm on carbon steel coupons. It is well known that planktonic cells are much easier to treat than sessile cells. D-amino acids are naturally occurring. They occupy a significant fraction of amino acids in processed food because of heat conversion of L-amino acids to D-amino acids. Because they are used as signal molecules only relatively low concentrations are needed. They can be used to reduce biocide dosage while achieving better efficacy. This work presents new experimental data on D-amino acid enhancement of biocide treatment of field biofilm consortia in lab tests thus paving the way for field trials.