GC–MS investigates cheese made from human bacteria - - Chromatography Online
GC–MS investigates cheese made from human bacteria

The Column
Volume 10, Issue 2, pp. 6

Researcher Christina Agapakis from the University of California, Los Angeles, USA, has come up with an unusual way of making cheese by taking bacteria from various parts of the human body and analyzing the odour of each cheese produced using headspace gas chromatography–mass spectrometry (GC–MS).1

Agapakis’ interest was piqued by the similarities between cheese and human microdiversity. Many of the smells that are used to describe cheese originate from the human body. “Many of the stinkiest cheeses are hosts to species of bacteria closely related to the bacteria responsible for the characteristic smells of human armpits or feet,” Agapakis commented. Swabs were taken from the hands, feet, noses, and armpits of subjects and inoculated into fresh, pasteurized, organic, whole milk. The samples were incubated overnight at 37 °C and the curds strained and pressed to produce the cheese.

The team found that even though the same milk and the same processes were used to produce the cheeses, they differed in colour, texture, and odour as a result of the different bacteria that were cultured.

The team analyzed the bacteria in the cheese using 16S ribosomal RNA sequencing. Several different species of bacteria were identified in the cheese that had also been found in metagenomic sequencing of isolates from the human body. In particular, Proteus vulgaris, closely related to Proteus mirabilis (found on hands, feet, noses, and in armpits) is found on cheeses and is noted for its strong aroma; Enterococcus faecalis (found in armpits) is a lactic acid bacteria found in raw milk and cheese; and Hafnia alvei (found in armpits) is an enterobacteria common in cheese and is added as a secondary culture in artisanal cheeses for a cauliflower-like flavour.
Headspace GC–MS was performed to identify volatile organic compounds and characterize the odour of each cheese. Agapakis commented: “This is cheese not for eating but for smelling, and for thinking about our very personal connections to the microbial world.”

The cheeses have just been exhibited at the Science Gallery of Trinity College Dublin, Ireland.

1. http://agapakis.com/cheese.pdf


blog comments powered by Disqus
LCGC E-mail Newsletters
Global E-newsletters subscribe here:



Sample Prep Perspectives | Ronald E. Majors:

LCGC Columnist Ron Majors, established authority on new column technologies, keeps readers up-to-date with new sample preparation trends in all branches of chromatography and reviews developments in existing technology lines.

LATEST: The Role of Selectivity in Extractions: A Case Study

History of Chromatography | Industry Veterans:

With each installment of this column, a different industry veteran covers an aspect of the evolution and continued development of the science of chromatography, from its birth to its eventual growth into the high-powered industry we see today.

LATEST: Georges Guiochon: Separation Science Innovator

MS — The Practical Art| Kate Yu:
Kate Yu is the editor of 'MS-The Practical Art' bringing her expertise in the field of mass spectrometry and hyphenated techniques to the pages of LCGC. In this column she examines the mass spectrometric side of coupled liquid and gas-phase systems. Troubleshooting-style articles provide readers with invaluable advice for getting the most from their mass spectrometers.

LATEST: Mass Spectrometry for Natural Products Research: Challenges, Pitfalls, and Opportunities

LC Troubleshooting | John Dolan:

LC Troubleshooting sets about making HPLC methods easier to master. By covering the basics of liquid chromatography separations and instrumentation, John Dolan, Vice President of LC Resources and world renowned expert on HPLC, is able to highlight common problems and provide remedies for them.

LATEST: LC Method Scaling, Part I: Isocratic Separations

More LCGC Chromatography-Related Columnists>>

LCGC North America Editorial Advisory Board>>

LCGC Europe Editorial Advisory Board>>

LCGC Editorial Team Contacts>>

Source: The Column,
Click here