Biofilm at Metalworking Fluid Surface – Sump Wall Interface.

Biofilms Part 1 Recap

In my last What’s New article I wrote:

Biofilms can form on any surface that is in contact with water. In aqueous systems such as heat exchanger, potable water, firemain, containing water-miscible metalworking fluid, biofilms can coat >90 % of surfaces in contact with the fluid. In systems containing fuels, lubricants, or other fluids in which water is not normally miscible, biofilms…

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 &…