## 3 Results
### Effect of Fortified Inoculation with L. brevis Lbr17 on the Fermentation Process  
In order to interpret the effect of fortified inoculation with Lbr17 on the fermentation process, we monitored the dynamics of biomass for total bacteria, total fungi, _Lactobacillus_, _Saccharomyces_, and _L. brevis_ throughout the fermentation process, as depicted in Figure 4. Additionally, we examined the concentration of the main volatile compounds after fermentation. Total bacteria: As displayed in Figure 4A, the change in total bacteria during the pre-fermentation period was similar between the fortified fermentation group (T group) and the control group (CK Group). However, after inoculation on the 25 th day, the total bacteria count in the fortified fermentation group (T group) increased significantly. Importantly, the increase in the total bacteria population was not attributed to changes in the number of _Lactobacillus_, as shown in Figure 4C. In addition to _Lactobacillus_, other bacteria involved in the fermentation process of fermented grains include _Pedicococcus_, _Streptomyces_, _Bacillus_, _Leuconstoc_, _Microbacteriumrium_, and _Corynebactinrium_[8]. Therefore, the rapid increase in bacterial count after inoculation on the 25 th day may be attributed to the reproduction of one or more of these bacteria. However, it is worth noting that this change in bacterial count did not have a noticeable impact on the pH and titratable acidity, suggesting that it would not lead to rancidity. Total fungi: As shown in Figure 4B, the copy number of total fungi exhibited a similar overall trend in both the fortified fermentation group (T group) and the control group (CK group). Initially, all of them showed a decrease on the first day, followed by an increase. This is likely due to the inoculation of the microbial community from _Daqu_ into the grain, leading to a decrease in the total fungal count as the fungi were not yet adapted to the new environment. Subsequently, as the fungi adapted to the environment, there was an increase in the copy number of the fungal population. However, there are differences between the two groups. In the fortified fermentation group (T group), the total number of fungi decreased sharply from the 15 th to the 21 st day, reaching its lowest value on the 21 st day, but subsequently recovered. This is possibly due to the accumulation of  
Figure 4: Microbial dynamics in fortified fermentation during fermentation. (**A**) Total bacteria; (**B**) total fungi; (**C**) _Lactobacillus_; (**D**) _Saccharomyces_; (**E**) _L. brevis_; CK: control group fermented with _Daqu_ as a starter; T inoculated group with _Daqu_ and strain Lbr17 for fortified fermentation. Values represent the means of three replicates with their standard error bars. acid produced by inoculated _L. brevis_, which leads to the death of fungi that cannot tolerate higher acidity. The recovery may be attributed to the reproduction of fungi that can tolerate higher acidity, filling the niche left by the dead fungi. Throughout the entire fermentation process, the total number of fungi in the fortified fermentation group (T group) was lower than that in the CK group. This indicates that the inoculated _L. brevis_ (Lbr17) had an inhibitory effect on the growth of fungi during the fermentation process. _Lactobacillus_: Figure 4C,E clearly demonstrate that the inoculation of _L. brevis_ has a significant impact on the number of _Lactobacillus_ during the fermentation process. During the initial 15 days, the fortified fermentation group (T group) exhibited a higher number of _L. brevis_ compared to the control group (CK group) due to the initial abundance of _L. brevis_. The relationship between _L. brevis_ and other _Lactobacillus_ exhibited mutually exclusive effects, whereas the extensive reproduction of _L. brevis_ hindered the growth of other _Lactobacillus_ strains. Beyond the 15-day mark, the total number of _L.