I loved Samin Nosrat’s book and can’t wait to watch the Netflix series! Have you seen it? Makes me think about basic elements of honeybee nutrition. I hope that the new research on the bees’ diet leads the reader to reflect: What do we feed the bees to set them up for success?
About honeybee taste receptors
Animals as diverse as fruit fly and humans recognize five typical tastes: sweet, bitter, umami (amino acid), salty, and sour (acid). Umami taste is important for foragers to discern pollen from different plants, having diverse amino acid compositions. The study conducted by Sooho Lim and colleagues published in 2019 issue of Scientific Reports identifies for the first time taste receptor in honey bee that respond to amino acids.
Taste receptor in honey bee that respond to amino acids.
This umami receptor, AmGr10 (that stands for Apis mellifera Gustatory receptor 10), is located in honeybee proboscis. Lim and colleagues found that the receptor was dramatically potentiated by ribonucleotides such as GMP and IMP, flavor enhancers helping honeybees have the best taste for pollen amino acids. Should we rush to add GMP and IMP to your pollen patty? It could be as simple as adding a little yeast. Fungal gut communities of healthy worker bees are naturally dominated by yeast belonging to genus Saccharomyces, which naturally produce IMP and GMP and naturally fine-tune foragers’ taste receptors to appetizing amino acids.
Yeasts enhance honeybee taste, but the plants add more microbes to enhance flavor! Yeast and bacteria present in the microbiota of nectar produce volatile compounds and determine nectar attractiveness. Basically, fungicides can really mess with pollination and honeybee nutrition.
Fatty acids are the ultimate frontier in honeybee nutrition.
Besides amino acids and nectar, Fat (or lipids or oils) is an element of honeybee nutrition largely ignored by beekeepers and researchers until recently. In December at Louisiana Beekeepers Association, Texas A&M students Pierre Lau and Alexandria Payne presented “Optimizing Macronutrient Ratios in Honey Bee Pollen Substitutes and How We Can Apply This Information For Honey Bee Pathogen Defense”. Pierre Lau has previously studied why honeybees like salty water. He received 2019 ESA Student Award for his work on lipid nutritional requirements of honeybees. Pierre first studied honeybee preferences for pollen substitute having different protein-to-fat ratios, and found highest consumption of pollen substitute having 3:2 protein-to-fat ratio. However, pollen substitute having 2:3 protein-to-fat ratio remarkably increased survival of honeybees infected with deformed wing virus (DWV). In contrast to the infected honeybees with low fat in their pollen substitute, infected honeybees fed 2:3 protein-to-fat ratio had the same lifespan as the honeybees not infected with DWV.
More dietary fat helped honeybees survive DWV infection.
Latest research from the Moran lab identified Bifidobacterium as most equipped for polysaccharide digestion. An amazing thing that these gut microbes do is they convert dietary carbohydrates to fats. Specifically, microbes convert sugars and fiber to short-chain fatty acids (SCFAs). SCFAs are a major nutrient source. As an additional benefit, gut microbes also make lactic acid which protects the gut from disease-causing microbes.
Science bring about new understanding to the words of Hippocrates : “Let food be thy medicine and medicine be thy food“. Let your bees have microbes with their food.
In 2020, Bee Science News will continue to educate beekeepers about the advances, the basics, and the interconnectedness of it all.