A biochemistry student at George Mason University in Fairfax, Virginia, has been analyzing proteins in honey. Since proteins (for example, pollen grains, shown above) make up only about 0.1-0.5% (one to five parts per thousand) of the volume of a typical honey sample, the scientist developed a ground-breaking system to poke through all that honey and look at the teeny bit of protein that’s there. In the process, she and her colleagues developed a new way to identify the types of pollen and other proteins lurking in raw natural honey.
Effectively examining protein in honey has been a long-term goal for palynologists, the folks who study pollen. Their task is to identify pollen in honey in order to determine floral source. Let’s say that you are a honey packer and you need to confirm that some honey for sale by a commercial beekeeper is mostly buckwheat, for example, and not badly burnt foul-tasting bakers’ grade honey. (Really, the two are hard to tell apart!) You would send the sample to a palynologist. She would whirl the honey sample in a centrifuge to concentrate the solids, then cook the material in acids to expose the unique exine patterns of the pollen grains. Next, the palynologist mounts the grains on a gridded microscope slide and counts the number of clover, jujube, and buckwheat pollen grains. The last step requires the most experience – you sit immobile on a lab stool for hours, listening to classic Norwegian heavy metal band Miksha blasting in your ear buds, counting pollen dust that only a few dozen people on Earth can recognize. This service costs about $200.
So, here’s the breakthrough. Rocio Cornero, left, originally from Mar del Plata, Argentina, used “multifunctional core-shell nanoparticles, which are a concentration method based on an affinity bait covalently bound to a polymer nanoparticle. When applied to a protein solution, the nanoparticles rapidly capture, concentrate and preserve solution-phase analytes, which can be then measured with standard analytical methods.” I kick myself that I hadn’t thought of this first!
That’s still the easy part. It gives you a little bottle of solution-phase analytes. How do you analyze the analytes? You simply set up “tandem mass spectrometry using a Thermo Fusion Orbitrap mass spectrometer”. Now we are getting somewhere. Tandem, of course means ‘two’ – like the tandem axles on your bee truck. The first mass spectrometer (MS) of this tandem setup separates the peptides (mostly pollen parts) by weight, then spits them into the second MS, which actually identifies the fragments. “Ah-ha!” you say. “Exactly how does it identify the fragments?” Well, not through a microscope in a palynologist’s lab. This new system is automated. However, you’ll need a reference guide that looks up and identifies the flying peptide chips. Rocio Cornero explains, “[we use] proteomic databases including Apis mellifera, geographically consistent plants, bee pathogens such as deformed wing virus, Varroa destructor, and Nosema ceranae, and plant pathogens. In order to ensure the specificity of the identified peptides, we applied a bioinformatics pipeline to compare peptide sequences to the entire RefSeq non-redundant database.” So, you need an instantaneous information delivery system (let’s call it a computer) and the entire non-redundant RefSeq, or peptide database. You’ll have to build your own RefSeq, or go to a a local RefSeq-builder. If there’s one nearby. I’d build my own.
If you were brave enough to read the previous paragraph, you noticed that the peptides (small protein-like molecules) that are identified include parts of bees’ knees, mites, and plant pathogens – all found in the original honey sample along with the pollen. (Should we tell our honey customers?) The pollen bits can identify floral sources that might have sourced the honey, but the honey sample also contains other peptides that can indicate which diseases your bees – and surrounding plants – are carrying! Now, I’m getting excited.
So, congratulations to Rocio Cornero and her mentors – Drs. Alessandra Luchini and Lance Liotta – at George Mason. This new method might be transformative. (See the abstract here.) Rocio Cornero hopes that the entire system will be available in a few years for beekeepers as an instantaneous, portable tool. The benefits could include identifying organic pesticides, bee diseases, pathogens, and pollen from flowers that made the beekeepers’ honey.
Rocio says that her father, a beekeeper, was her inspiration. He passed away this year in Argentina. Among the test honey which proved her system will work were two samples from her father’s bees – the last honey he ever produced.