While the simple sugars present in nectar and honey may temporarily support a gut microbial community, elemental building blocks (nitrogen, phosphorous, and co-factors) from pollen protoplasm or royal jelly are necessary for microbial reproduction and persistence. The temporal and spatial availability of these nutrients will determine in part the microbial abundance and diversity throughout the hive and honey bee gut. Microbes adapted primarily to the social stomach may have limited or ephemeral access to pollen protoplasm. Evidence suggests that pollen digestion begins in the honey bee midgut, initiated in part by the transition from high to low osmotic pressure causing the pollen protoplasm to swell, a process demonstrated to rupture pollen grains in vitro (Kroon et al., 1974). However, ingested pollen is delayed while passing through the social stomach and piles up as a bulbous mass while being filtered through the proventriculus.

Colony microbial balance.pdf (298.70 kb)