Bacteria; Pseudomonadota; Alphaproteobacteria; Rhodospirillales; Acetobacteraceae; Bombella
Description and Significance
Bombella apis is a rod-shaped, nonmotile, aerobic Gram-negative bacterium. Bombella apis can be found in the midgut of honey bees.
Bombella apis has a genome comprised of a single circular chromosome that is 2,086,308 bp long and contains 1,975 protein-coding genes. It has a GC content of 59.56%.
Cell Structure, Metabolism and Life Cycle
Bombella apis is an acetic acid bacterium that does oxidative fermentation. It acquires nitrogen from ammonia, carbon from glucose, and energy from sugars and amino acids. B. apis has also been found to thrive in 30% glucose solutions.
Their cells are non-motile, aerobic, and Gram-negative rods that are 1.0–2.5 µm in length and 0.5–0.6 µm wide.
Ecology and Pathogenesis
B. apis is found in the midgut of honey bees (Apis mellifera). It occupies well-defined niches within the hive: the queen, nurse pharyngeal glands, nurse crops, food stores, and royal jelly. It spreads as nurse bees feed other hive members.
Bombella apis has been sequenced and found to be closely associated with nectar, developing honey bee larvae, and honey bee queens.
Bombella apis has also been found to be able to protect themselves against bacteriophages.
B. apis has been shown to inhibit Aspergillus flavus and Beauveria bassiano. The mechanism hypothesized for this inhibition is a possible secreted polyketide. All the known strains have a type 1 polyketide sythase gene cluster, a feature common to many symbionts with antifungal activity. This mechanism has been shown to inhibit fungal growth in-vitro and in-vivo.
B. apis contributes to the environment because A. mellifera is responsible for 1/3 of American food consumed. They are an important pollinator that one survey found ~5% of worldwide flowering plant species depend on, and 51% of flowering plant species are at least sometimes pollinated by. Colony Collapse Disorder (CCD) is a major threat to A. mellifera that may lead to the extinction of the species. CCD is known to be contributed to by fungal infection, and artificial fungicides may also contribute to CCD. B. apis could be a possible counteragent in CCD by combatting fungal infections and partially reducing the need for artificial fungicidal chemicals.
- Bombella apis JCM 31623 is an obligate aerobe, mesophilic, Gram-negative Proteobacterium that forms circular colonies and was isolated from midgut of the honey bee in South Korea, BacDive. https://bacdive.dsmz.de/strain/140538. Accessed April 28, 2022
- Smith et al., Draft Genome Sequence of a Bombella apis Strain Isolated from Honey Bees, Microbiology Resource Announcements, Volume 8, Issue 47. https://journals.asm.org/doi/full/10.1128/MRA.01329-19 Accessed April 28, 2022
- Smith et al., Genomic Signatures of Honey Bee Association in an Acetic Acid Symbiont, Genome Biology and Evolution. https://pubmed.ncbi.nlm.nih.gov/32870981/ Accessed April 28, 2022
- Yun et al., Bombella apis sp. nov., an acetic acid bacterium isolated from the midgut of a honey bee, International Journal of Systematic and Evolutionary Microbiology, Vol. 67, Issue 7. https://www.semanticscholar.org/paper/Bombella-apis-sp.-nov.,-an-acetic-acid-bacterium-of-Yun-Lee/6bc7277be53f849c46d5ff573d8c510c4946936c
- Miller et al., A Bacterial Symbiont Protects Honey Bees from Fungal Disease, mBio, Volume 12, Issue 3. https://journals.asm.org/doi/full/10.1128/mBio.00503-21 Accessed 28 April 2022
- Food and Drug Administration, Helping Agriculture’s Helpful Honey Bees. https://www.fda.gov/animal-veterinary/animal-health-literacy/helping-agricultures-helpful-honey-bees Accessed April 28 2022
- Hung et al., The worldwide importance of honey bees as pollinators in natural habitats, The Royal Society, Volume 285, Issue 1870. https://royalsocietypublishing.org/doi/10.1098/rspb.2017.2140 Accessed April 28, 2022
- Pettis et al., Crop Pollination Exposes Honey Bees to Pesticides Which Alters Their Susceptibility to the Gut Pathogen Nosema ceranae, PLoS One. https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0070182&type=printable Accessed April 28, 2022
Page authored by Emily Taylor, Cullen Vincent, and Alexis Vo, students of Prof. Jay Lennon at IndianaUniversity.