Past efforts by bee researchers to inventory the fungal diversity in bee colonies have revealed that almost all often present in the hive. In a recent study, researchers have discovered that this fungus is uniquely adapted to survive in bee colonies.
The western honey bee stores large amounts of food in the shape of bee bread, which is used as a very important food source for the hive. The abundant nutrients of this food source also make it a horny goal for microorganisms. However, bee bread is acidic with little moisture, and is infused with the antimicrobial chemical propolis.
Despite the inhospitable nature of bee bread, the microbiome within the hive incorporates many bacterial and fungal species which can be essential for bee food preparation, storage, and digestion.
“Most research on bee bread has focused on bacteria and it was assumed that fungi did not play a major role because the bacteria made it too inhospitable for them,” says Birenbaum (IGOH/). said Daniel Bush, a graduate student. GEGC/GNDP) Lab. “After speaking with a mycologist, I suspected this was not the case and set out to demonstrate that the fungus is capable of living successfully in bee bread.”
In the study, the researchers used three strains: one which was not present in honey bee hives, a strain that was isolated from hives in central Illinois, and a pathogenic strain from a honey bee colony with gallstones. There was an infection.
They first tested whether the strains showed any differences of their response to pH and temperature. The latter was observed because hives are characterised by higher year-round temperatures than the skin environment, which is a challenge for a lot of microbes. Although all strains were capable of grow at different temperature ranges, there was a marked difference in growth under different pH conditions. The strain isolated from the hive was capable of tolerate low pH, while the opposite two couldn’t.
Stress was also tested under different matric potentials, which indicate how much moisture is obtainable, and the response of propolis. “We found that the hive-derived strain was able to cope with extreme levels of environmental stress from colony-specific sources,” Bush said. “It was interesting that it could deal with propolis, which is believed to have fungicidal properties.”
To higher understand how the fungal species related to the hive were capable of adapt, the researchers also sequenced the strain and located that it had several genetic variations that made it tolerant of the tough conditions of the bee hive environment. Allowed.
“We think these are signs that the fungus has a level of adaptation that helps it live with bees,” Bush said. “We suspect that there are some mutual benefits for the two organisms, but we don't have enough evidence yet.”
The researchers now hope to check how the fungus reacts to different bee bread recipes during its life. They hope their work will make clear how fungicides routinely used to guard beehives affect these microbes.
The study was published in “Strains from Western honey bee bread () show adaptations to specific characteristics of the hive environment” and will be found at 10.1002/ece3.10918. This study was supported by the Agriculture and Food Research Initiative.