Honeybees provide many services to enhance the ecosystem; perhaps their most well-known service is providing honey rich in unique nutrients. However, there is another task that some may overlook, even though it is pivotal in supporting life on Earth; that is pollination, which is the transfer of pollen grains. During this process, the DNA carried within pollen grains is transferred from the stamen (the male part of the flower) to the pistil (the female part of the flower), helping to complete the process of reproduction.
Pollen grains are usually microscopic and measured in micrometers. However, it turned out that they offer a previously unknown benefit: protecting honeybees from diseases by producing antimicrobial compounds capable of inhibiting pathogens that affect honeybees as well as plants. This is what a study published in the journal "Frontiers in Microbiology" in 30 September 2025 found.
How Are Antimicrobial Compounds Secreted?
At the microscopic level, there is another world that the naked eye cannot percieve. These microorganisms—including the beneficial microbes and various pathogens—that inhabit that microscopic world need food sources in order to grow, survive, and complete their normal lifecycle. Meanwhile, a fierce competition for resources takes place among these species. It is here that microbes begin secreting secondary antimicrobial substances that inhibit the growth of or kill other microbial species in the medium. Consequently, the microbes that secreted these substances secure the available resources, allowing them to grow and flourish.
From this perspective, the researchers considered that pollen might contain a source of antimicrobial agents that helps immunize honeybees against pathogens. They worked to prove or disprove that hypothesis.
A Hidden Source of Medicine!
Between April and June 2021, the researchers collected pollen from ten plant species as well as pollen stores from honeybee hive. Next came the isolation step, during which they focused on isolating antinobacteria; they are the source of nearly two-thirds of the antibiotics used today. In fact, they succeeded in isolating 16 strains from the plant samples and 18 strains from the pollen stores within the honeybee hive.
After identifying the strains, researchers discovered that 72% of them belong to a genus of symbiotic bacteria called Streptomyces, which is known for producing antimicrobial substances. The researchers tested the effectiveness of the bacteria in inhibiting pathogens, noting that the isolated strains demonstrated efficacy against two types of honeybee pathogens and three types of agricultural crop pathogens.
When honeybees collect pollen containing that actinomycete bacteria, which secrete antimicrobials and store it in their cells, forming a natural defense system, which helps protect bee colonies against lurking diseases. The study results indicated that the richer the surrounding environment is in diverse plant species, the greater the likelihood of a wider variety of microbes in the pollen; thus, increasing the type of antimicrobials available to the hive, which means stronger immunity for the honeybee hive.
References
jcu.edu.au
frontiersin.org
ourworldindata.org
pmc.ncbi.nlm.nih.gov
Cover image by Magnific