Version 1: The Relationship between microbial population adenosine triphosphate and quantitative polymerase chain reaction bioburdens in diesel fuel microcosms

Fluid samples drawn from the fuel, interface, and water phases of fuel over water microcosms were tested for cellular adenosine triphosphate concentration ([cATP]), and quantitative polymerase chain reaction (qPCR) bioburdens. Additionally, surface swab samples from steel corrosion coupon surfaces exposed to each of these three phases were collected and tested for total ATP concentration ([tATP]) and qPCR bioburdens. Relationships between ATP and qPCR bioburdens were examined. Correlation coefficients between the two variables were matrix dependent and ranged from negligible (|r| = 0.2) to strong (|r| = 0.7). When results were categorized into negligible, moderate and heavy bioburdens, parameter agreement was again matrix dependent and ranged from 11% to 89% – with qPCR-bioburden ratings typically being greater than ATP-bioburden ratings.