## 4 Discussion  
The composition of bacterial communities mainly consisted of Proteobacteria and Firmicutes across all treatments used (ranging from 56.30% in VC to 82.10% in ZM-w). Proteobacteria are primarily responsible for nitrogen fixation in soil [38], whereas Firmicutes have been identified as disease-suppressing microbes [39]. The presence of these two dominant bacterial phyla constitutes a significant part of the bacterial community in vermicompost [40], as was also recorded in the bacterial profile of the TM variant [41]. Integrated and biological methods are increasingly used in agriculture, replacing chemical-based solutions and sometimes proving more effective. Using natural sources from earthworms and their products through vermicomposting can offer natural alternatives to synthetic chemicals, like fertilizers and pesticides. These alternatives not only benefit plant cultivation, but also help combat various soil pathogenic fungi, such as _Rhizoctonia solani_, _Alternaria solani_, _Aspergillus niger_, _A. flavus_, _Fusarium oxysporum_, and _F. graminearum_[42]. Moreover, increasing the share of vermicompost has been shown to enhance the survival of bacteria used as biofertilizers, such as _Azotobacter chroococcum_, _Bacillus megaterium_, and _Rhizobium leguninosarum_[43]. The application of vermicompost biofortified with selected biological control agents (BCAs), i.e., _Trichoderma harzianum_, _Pseudomonas fluorescens_, and _Bacillus subtilis_, resulted in a lower incidence of disease symptoms, in addition to improving plant growth and yield [44]. Our results demonstrated a high abundance of genus _Bacillus_ (18.2% in VC and 16.4% in TM) (Table 1). It is worth bearing in mind that fungi of the genera _Trichoderma_ and _Pseudomonas_ have positive effects on the increasingly important threat in rapeseed cultivation, which is the fungus of the genus _Verticillium_[45]. Interestingly, in the ZM-w variant, there was a large number of bacteria from the order Rhizoles (52.2%), which shows a strong dependence on chitinases (Figure 4B), known for their ability to degrade fungal cell walls [46]. This might have ecological significance in its interactions with pathogenic fungi as biological control agents. Moreover, organic compounds resulting from the use of vermicompost can stimulate microbial activities and increase mineralizing and nitrifying enzymes [47], thus promoting nutrient turnover [48]. We previously showed that increased nitrogen levels encouraged the proliferation of aerobic spore-forming bacteria, which generate antibiotics useful as biocontrol agents. Moderate fertilizer levels led to the accumulation of nitrogen in bacterial biomass [49]. Additionally, the activities of symbiotic microbes, alongside gut enzymes like cellulase, protease, chitinase, and acid phosphatase, play crucial roles in converting ingested soil and organic matter into a valuable product rich in essential nutrients and active components of microbial biomass [50]. We also showed that higher frass rates increased the abundance of microorganisms supporting organic matter mineralization [27]. Symbiotic microbes living in the soil play key roles in the life, growth, and health of most plants. Some host plants can attract beneficial microorganisms through their roots, which helps them fight pathogens [51]. The use of vermicompost (VC) and mealworm frass (TM) resulted in the significantly highest values of red beet biomass in this research (Table 2, Figure 3). Both vermicompost and frass from mealworm feeding have properties that accelerate the decomposition of organic matter and increase the content of available nutrients for plants (N, P, and K). In addition to nitrogen and potassium, phosphorus is one of the key elements for the proper development of plants, especially at their initial stage. Unfortunately, this ingredient is often found in the soil in a form that is inaccessible to plants. This is due to its poor solubility in soil solution, low concentration, and low mobility.