# Farmed Insect Frass as a Future Organic Fertilizer
## 3 Results and Discussion
### Changes in the Bacteriobime Community and Relationships with the Analyzed Parameters
[57], the abundance of Acidobacteria in soil rich in organic matter was significantly correlated with a decreasing pH and cation exchange capacity. In the current study, three genera of the phylum Acidobacteria maintained their dominant status, and Ca. Solibacter increased its dominance when the soil pH decreased over two months. The exact roles of Ca. Solibacter and Ca. Koribacter remain unknown, but the dominant status of these genera could be used as a bioindicator to identify substrates that do not support microbial development. High abundance of these bacterial genera could compromise the total biological activity of soil, nutrient cycling, and symbiotic interactions between plants and other microbial groups. The genus _Dokdonella_ exhibited different dominance patterns, increasing in urea treatments and becoming dominant in U400. _Rhodanobacter_ spp., initially dominant, became rare in F50-F200, U100, and U200, and subdominant in U50 and U400, remaining dominant only in F400. _Flavsibilbacter_ spp., initially subdominant, decreased in F200 and F400. _Pseudolabrys_ spp. increased after urea and frass applications. _Lysobacter_ spp. and _Granulicella_ spp. showed varied dominance patterns near the threshold, with _Granulicella_ spp. having lower proportions in all treatments. _Rhodoplanes_ spp. remained consistent, except in F400. _Chitinophaga_ spp. increased with urea. _Methylocystis_ spp. and _Devosia_ spp. showed minor dominance pattern variations, rising after the application of F200. Other genera had a relatively low share of the total population, with a single subdominant taxon. A high proportion of _Dokdonella_ spp. and _Rhodanobacter_ spp., of the family Rhodanobacteraceae, in particular after the application of the highest N rates, indicates that they depend on the availability of oxidized N compounds. Both genera reduce nitrates and are well adapted to environments with a low pH (in particular, _Rhodanobacter_) [58; 59; 60]. The order Rhizolates dominated in all analyzed samples, with a high proportion of the genus _Bradyrhizobium_, which was more prevalent in the rhizosphere than in the soil. Rhizobacteria enter symbiotic relationships with legume plants by forming root nodules that enable atmospheric N fixation. _Bradyrhizobium_ bacteria are root symbionts, ubiquitous in the soil and legumes, which have also been found on the surface of sugar beet roots. Research has shown that both diazotrophic and non-diazotrophic _Bradyrhizobium_ strains can colonize the root zone of both leguminous and non-leguminous plants. The group of free-living _Bradyrhizobium_ spp. includes both diazotrophs and strains incapable of N fixation, most of which are capable of denitrification, H\({}_{2}\) uptake, photosynthesis, and carbon fixation [61; 62; 63; 64]. It appears that the above properties can be used to regulate nutrient availability in the rhizosphere, and to modify unfavorable environmental conditions within the root zone. Figure 2: _Cont._  
_Nitrospira_ spp. were subdominant in the treatment supplied with the highest urea rate. This genus contains a complete set of _amo_ and _hao_ genes required for the oxidation of both NO\({}_{2}\)\({}^{-}\) and NH\({}_{4}\)\({}^{+}\) to NO\({}_{3}\)\({}^{-}\), as well as complete ammonia oxidation. The increase in nitrate N levels could also be attributed to increased counts of denitfriying and nitrate assimilation bacteria, such as _Optituts_ spp. [65; 66]. _Rhodoplanes_ and _Pseudolabrys_ are also interesting genera of photosynthetic bacteria, which are plant symbionts and participate in carbon and N cycles. Most photosynthetic bacteria effectively fix molecular N, but _Rhodoplanes_ spp. can also utilize N from the decomposition of urea. These bacteria rely on various substrates as carbon sources and readily utilize organic acids [67]. In the present study, the total abundance of _Rhodoplanes_ and _Pseudolabrys_ increased after urea application. The absence of a light period during peat incubation probably triggered heterotrophic metabolism.