Metalworking fluid return sluice cover plate; underside, showing biofilm build-up.

What are biofilms?

ASTM1 defines biofilm as a noun: “microorganisms living in a self-organized community attached to surfaces, interfaces, or each other, embedded in a matrix of extracellular polymeric substances of microbial origin, while exhibiting altered phenotypes with respect to growth rate and gene transcription.” The ASTM definition adds: “Biofilms may be comprised of bacteria,…

Microbes do not care whether operators accept the science.

Can microbes degrade turbine oil and cause damage to turbine oil systems?

The short answer is yes.

In 2018, as part of an Energy Institute sponsored project, I invited more than 100 turbine system operators to complete a survey designed to assess biodeterioration risk awareness and operational measures (for example, condition monitoring practices) for reducing the risk. Concurrently, I sent a similar invitation to…

One of the more famous quotes from William Shakespeare’s play, Romeo and Juliet.

Language Matters

In this month’s article I’ll address the use of what I call unregistered microbicides.

Over the course of the past several decades, industry and regulators have taken increasingly jaundiced views of chemical substances variously known as antimicrobial pesticides, biocidal substances, biocides, biocidal products, and microbicides. What are these substances? The EU’s…

Sources of Variation. Homogeneity – the non-uniform distribution of microbes in the sample source (VSOURCE, where V = variability), the sample (VSAMPLE) and the specimen (VSPECIMEN) – contributes substantially to test result variability.

It’s Not the Method

A few years ago, a single set of fuel and fuel-associated water samples were used for two ASTM interlaboratory studies (ILS). You can read the details in the paper published in International Biodeterioration &…

Most commonly, quantitative recovery applies when a method consistently detects a substantial percentage of the intended analyte in a specimen. Read on to learn more.

Analytes and Parameters

In chemistry, an analyte is a substance or material being measured by an analytical method. In microbiology, the analyte is either microbial cells or molecules. A parameter is a property used to quantify an analyte. Direct counting – using either a microscope or a flow cytometer – is…