The authors investigated airborne bacterial and fungal communities and their associations with sugar compounds at a typical rural site, Dingxing County, in the North China Plain. Their community structure, source, diural variation, possible factors, and contribution to sugar compounds were addressed in this manuscript. The results are conducive to deepening the understanding of bioaerosol and those potential influence on the enhanced sugar compounds at nighttime. This is a valuable piece of work also with a reasonable overall structure. I recommend that it can be accepted for Minor Revision.

Minor

1. For the SourceTracker, soils, plant leaves and seawater were selected as the source tracking reference databases. But the sources of bacterial community were mostly unresolved.(about 98.9%). I wondered whether the database was precise or not? Is there any seawater around the sampling site? Did the nearby river water contributed more to the bacterial community?
2. It seems that the environmental factors did not explain adequate variance of bacterial community also by the RDA analysis. The cumulative explanatory variableof RDA1 and RDA2 axis were lower than 60%, hence did the RDA analysis have statistical significance or more factors should be included.
3. The results showed that nighttime fungal spore emitted more OC than that in daytime (p < 0.01, Fig 5b), however daytime samples were more affected by OC than the nighttime samples based on the redundancy analysis (Fig 4b). How to evaluate the different phenomenon?

The authors investigated the association of sugar molecules and the microbial community at taxonomic levels in atmospheric aerosols and found that sugar compounds exhibited significant associations with fungal community structure than bacterial community structure. And this strong associations between fungal community and sugar compounds in rural aerosols may due to the entire fungal community rather than specific fungal taxa. Overall, this study was well-designed, interesting and complete. The results observed could add substantially to the literature, provide a reference for further studies exploring the contribution of bioaerosols to organic carbon in atmospheric aerosols and build links between airborne microorganisms and aerosol chemistry. I would suggest the publication of this manuscript after addressing the following comments.

1. Since the samples were collected in the summer of 2020 (7−13 August). Did the high temperature affect the association of sugar molecules and the microbial community at taxonomic levels in atmospheric aerosols?

2. Why the authors chose the TSP samples? If the authors wanted to investigate the contribution of bioaerosols to organic carbon in atmospheric aerosols, it’s better to collect PM_2.5 or PM₁₀ samples.

3. The microbial community may be affected by air quality parameters such as PM_2.5, PM₁₀, NO₂, O₃, SO₂ and CO. The sugar compounds may be also affected by these pollution factors. I suggest the authors add some analysis about these parameters (also the air temperature).

4. The authors used the filters to collect the sugar samples. Did the author test the recovery efficiencies of these sugar compounds from the filter?