Applying microbial organic fertilizer (MOF) effectively improves soil tilth and microbial diversity. However, there were few studies about the changes incurred in the physicochemical properties and bacterial diversity in the farmland of North China at a large-scale following MOF application. This study aimed to investigate the soil physicochemical properties and bacterial community following MOF application. A total of 910 t MOF was used on 173 hectares of degraded soil, and the results indicated increased nutrients in the top plough layer. Compared to controls, the treated samples had significant higher organic matter, total nitrogen, available phosphorus, potassium, and hydrolyzed nitrogen (p < 0.05). Furthermore, MOF application also induced a slight increase in the soil bacterial richness, but a significant decrease in the evenness was observed, where Firmicutes, Actinobacteria, and Bacteroidetes were enriched in the treated group, with Bacillus and Arthrobacter being the dominant genera, accounting for 0.291 and 0.136, respectively. Similarly, an increase in the proportion of Pseudomonas and Psychrobacillus was also observed at up to 0.038 and 0.034, respectively. The MOF treatment improved complex carbon metabolism and nitrogen reduction functions, inhibiting nitrogen oxidation as represented by nitrification. Redundancy and correlation analyses showed that total nitrogen, available phosphorus, and pH were the main factors driving the soil microbial community. This study concluded that MOF application could improve the soil’s physicochemical properties and enhance the abundance and function of soil microbes, which is an effective method for improving the soil tilth and ecology of farmland in north China.

Antibiotic residues lead to the risk of resistance gene enrichment, which is the main reason why penicillin mycelial dreg (PMD) is defined as hazardous waste. Hydrothermal treatment (HT) is an effective method to treat penicillin mycelial dreg, but the degradation mechanism of penicillin is unclear. In the study, we researched the effects of pH (4–10) at 80–100 °C and metal ions (Mn²⁺, Fe²⁺, Cu²⁺, and Zn²⁺) at several concentrations on the HT of penicillin, identified the degradation products (DPs) under different conditions, and evaluated the antibacterial activity of hydrothermally treated samples. The results show that penicillin degradation kinetics highly consistent with pseudo-first-order model (R² = 0.9447–0.9999). The degradation rates (k) at pH = 4, 7, and 10 were 0.1603, 0.0039, and 0.0485 min⁻¹, indicating acidic conditions were more conducive to penicillin degradation. Among the four tested metal ions, Zn²⁺ had the most significant catalytic effect. Adding 5 mg·L⁻¹ Zn²⁺ caused 100% degradation rate at pH = 7 after HT for 60 min. Six degradation products (DPs) with low mass-to-charge (m/z ≤ 335) were detected under acidic condition. However, only two and three DPs were observed in the samples catalyzed by Zn²⁺ and alkali, respectively, and penilloic acid (m/z = 309) was the main DPs under these conditions. Furthermore, no antibacterial activity to Bacillus pumilus was detected in the medium with up to 50% addition of the treated samples under acidic condition. Even though acid, alkali, and some metal ions can improve the degradation ability of penicillin, it was found that the most effective way for removing its anti-bacterial activity was under the acidic condition. Therefore, resistance residue indicates the amount of additive in the process of resource utilization, and avoids the enrichment of resistance genes.

To develop a non-thermal method to replace steam autoclaving for white-rot fungi fermentation, Irpex lacteus spawn was inoculated in wheat straw (WSI) or ensiled WS (WSI) at varying ratios of 10%, 20%, 30%, 40%, and 50%, and incubated at 28 °C for 28 days to determine the effects of the ensiling and inoculation ratio on the colonization and degradation ability of Irpex lacteus in wheat straw (WS). The results demonstrate that ensiling effectively inhibited the growth of aerobic bacteria and molds, as well as other harmful microorganisms in WS, which created a favorable condition for the growth of I. lacteus. After the treatment of I. lacteus, the pH of EWSI decreased to below 5, while that of WSI, except for the feedstocks of WSI-50%, was around 7, indicating that I. lacteus colonized well in the ensiled WS because the substrates dominated by I. lacteus are generally acidic. Correspondingly, except for the molds in WSI-50% samples, the counts of other microorganisms in WSI, such as aerobic bacteria and molds, were significantly higher than those in EWSI (p < 0.05), indicating that contaminant microorganisms had a competitive advantage in non-ensiled substrates. Incubation with I. lacteus did not significantly affect the cellulose content of all samples. However, the NDS content of EWSI was significantly higher than that of WSI (p < 0.05), and the hemicellulose and lignin contents were significantly lower than the latter (p < 0.05), except for the NDS and hemicellulose contents of WSI-50% samples. Correlation analysis revealed a stronger negative correlation between NDS content and the contents of hemicellulose, cellulose, and lignin in EWSI, which could be caused by the destruction of lignin and hemicellulose and the conversion from structural carbohydrates to fungal polysaccharides or other compounds in NDS form. Even for WSI-50% samples, the sugar yield of WS treated with I. lacteus improved with an increasing inoculation ratio, but the ratio was not higher than that of the raw material. However, the sugar yield of EWSI increased by 51–80%, primarily owing to the degradation of lignin and hemicellulose. Above all, ensiling improves the colonization ability of I. lacteus in WS, which promotes the degradation of lignin and hemicellulose and the enzymic hydrolysis of cellulose, so combining ensiling and I. lacteus fermentation has promising potential in the pretreatment of WS.