## 4 Discussion
_Bacillus coagul_ and _Bacillus thermoamylovorans_ were dominant in the thermophilic stage of composting and had a greater capacity to degrade less biodegradable, complex organic compounds such as lignocellulosicoloses [61]. _Olivbacter oleidegradans_ was isolated from a biofilter clean-up facility on a hydrocarbon-contaminated site, whereas _Olivbacter composti_ sp. nov. was isolated from compost collected at a greenhouse (shih). At pilot-scale composting, the growth of _Halotalea_uc_, _Corynebacterium nuruki_, and _Lactobacillus acidipiscis_ was facilitated by the addition of the functional microbes. Previous reports have mentioned that _Sphingobacteriaceae_ and _Halotalea_ were dominant species in functional compost [62]. _Corynebacterium nuruki_ was isolated from an alcohol fermentation starter, which was a mixture of grains and various micro-organisms including mold, yeast, and bacteria (Shin). There was a significant dominance of members of the _Lactobacillus_ genus (_L. brevis_, _L. plantarum_, _L. oris_, and _L. jolonsoni_) and _Lactobacillus acidipiscis_ as a minor species [63]. It appeared that _Corynebacterium nuruki_ and _Lactobacillus acidipiscis_ originated from the rice bran used for composting materials in this study. Recent findings proved that _B. coagul_ might produce specific enzymes such as nitrile hydratase, endoinulinase, and alkaline lipase used for electrotransformation and fermentation for composting [64]. _Lactobacillus acidipiscis_ was reported as a compost bacterium to be linked with nitrogen metabolism and fermentation in compost [65]. PT-1 had a significantly higher TFC, whereas PT-1 and PT-2 demonstrated a higher level of TEAC compared to each control (Figure 7c,d). This indicated that inoculation with the functional microbes (SB-3, SB-4, and St-3) during the stabilization stage of the composting process can enhance the antioxidant components in pepper plants. DPPH and TPC showed much higher activity with the range of 60-70% of SCV and 700-1000 GAE mg/kg compared to the previous compost augmented with PGPB [66]. The high QE of PT-1 in the total flavonoid content and PT-1 and PT-2 in TEAC proved the dominance of antioxidant activity through the bioaugmented compost (Figure 7c,d). Flavonoids have hydroxyl groups that are functional in promoting free radical scavenging activity and ABTS chelation of metal ions, hence mediating antioxidant activities [67]. It was hypothesized that plant growth-promoting bacteria (PGPB) facilitate the production of non-enzymatic antioxidants and increase the availability of mineral nutrients. It was reported that PGPB also release/increase the availability of mineral elements such Cu, Fe, Mn, Zn, etc., to plants by chelation and acidification of soil [57]. Siderophore production may be a major feature of PGPB. It is essential for certain iron-sulfur complex enzymes and iron-containing proteinsand plays a major role in plant growth by participating in the synthesis of chlorophyll. Evidence also shows that beneficial microbes can enhance plants' tolerance to adverse environmental conditions [68]. For example, due to the application of a potassium-releasing strain of _Bacillus edaphicus_, enhanced plant growth and potassium uptake were reported under nutrient deficiency and heavy metal contamination in cotton and rapeseed [69]. Similarly, in this study, radish and pepper plants treated with the SB-3, SB-4, and St-3 cultures showed higher growth rates and increased antioxidant activity. The higher germination indices of TPP and TPF, and the higher growth rate of TPF indicated that treatment with SB-3, SB-4, and St-3 cultures was effective in stimulating radish growth in the presence of plant pathogens (_Pythium ultimum_ and _Fusarium oxysporum_ f. sp. _lactucae_) (Figure 8). Research showed that biological control agents including _S. sasae_ can produce hydrolytic enzymes, such as protease, glucanases, amylase, and chitinase, to destroy the components of the fungal cell wall, which is an important mechanism involved in the biocontrol of phytopathogenic fungi [70].