What samples are most useful for microbiological testing?

Earlier this week a colleague asked me to prepare a short piece about collecting samples from fuel systems when the intention was to perform microbiological tests. My initial response was to refer her to ASTM Practice D7463 Manual Sampling of Liquid Fuels, Associated Materials and Fuel System Components for Microbiological Testing and my recently published chapter on sampling in ASTM Manual 1, 9th Edition. My colleague responded…

In the June issue of Lubes’n’Greases, Jack Goodhue wrote a an article about the Zen concept – shoshin – beginner’s mind.  Normally a fan of Jack’s Your Business column, I was surprised by how far off the mark he was in his understanding of shoshin.  I wrote a letter to the editor to express my concerns, and a condensed version of my letter was published in this month’s issue. I believe that when used appropriately, shoshin is of tremendous value to business…

In May 2018, ASTM Subcommittee E34.50 on Health and Safety Standards for Metal Working Fluids commissioned a new Task Force (TF) to develop a new Standard Guide for Evaluating Water Miscible Metalworking Fluid Foaming Tendency. Justin Mykietyn, of Munzing, is chairing the TF and the work is being completed under ASTM Work Item 64558. The details are explained in an article that appeared in the August 2019 issue of Lubes’n’Greases magazine, pages 30 to 32. To learn more about the challenges…

What Does “Viable But Not Culturable” Mean and Why Should I Care?

In microbiology, the term used to describe microbes that appear to be healthy and active by test methods other than culturing is viable but not culturable – VNBC. Since the term first came into vogue in the 1980s, it has always reminded me of the Monty Python skit in which the customer – played by John Cleese – and the shop owner – played by Michael Palin – debate whether the parrot that Mr. Cleese had just bought…

Diesel fuel biodeterioration is not affected by the fuel’s sulfur content.

There is a broadly embraced misperception about the relationship between diesel fuel’s sulfur content and its toxicity to microorganisms. This misperception is driven by two logical flaws.

Logical argument #1:

There has been an increase in the number of microbially contaminated fuel systems since the use of ultra-low-sulfur diesel (ULSD) became mandatory.

Therefore, microbial contamination in low…