The farmland residual film pollution caused by traditional PE film has an adverse impact on crops and the environment. Polypropylene carbonate (PPC) film is a fully biodegradable film that can alleviate “white pollution”. In this study, the soil physicochemical properties and the composition and function of the soil community of FM (PPC film mulching) and CK (no film) treatments were determined to explore the effect of PPC film mulching on soil and the soil microbial community. Furthermore, the microorganisms at different time periods during the degradation of PPC mulch film were also analyzed. The results showed that film mulching increased soil pH but decreased the contents of EC and SOC, and there was no significant difference in the contents of AP and AK. The relative abundance of the phyla Acidobacteria was increased with film mulching, and the relative abundance of the genera MB_A2_108 also increased in the film mulched soil. Among the soil physicochemical properties, pH and SOC were the most important factors leading to changes in the composition of the bacterial and fungal communities. PPC film mulching had no significant effect on soil microbial community abundance and diversity. In addition, Pseudomonas, Flavobacterium, and Rhizobacter were dominant in the degradation of PPC film. Our research results provide a scientific theoretical basis for soil safety and the large-scale use of PPC biodegradable mulching films and a research foundation for the degradation of PPC plastics.
As one of the organic pollutants in industrial wastewater, phenol seriously threatens the environment and human health. Among various methods, microbial degradation of phenol possesses the advantages of nontoxicity and no secondary pollution. Therefore, search for microbial resources that can efficiently degrade phenol has become an important issue. In this study, a strain that could efficiently degrade phenol was isolated. The strain was identified as Bacillus cereus based on its morphology, physiological and biochemical features and 16S rRNA sequence analysis. The strain can completely degrade phenol up to 1,500 mg/L within 26 h (57.7 mg·L−1·h−1), under the optimum conditions, faster compared with the known degrading bacteria. The strain could efficiently remove phenol at a wide range of temperatures (22–37 °C) and pH (7–9), and Mn2+ and Zn2+ stress. Interestingly, this strain displayed the potential on microthermal environment, which could degrade 1,200 mg/L phenol within 36 h at 22 °C. Further, the strain had capacity that used a variety of aromatic compounds as the sole carbon source for growth. This study shows a useful biodegradation route on the wastewater treatment under high phenol concentration conditions, providing alternatives for environmental remediation.
Phenol is a serious pollutant to the environment, therefore, it is urgent to find a rapid and effective method for its removal. In this study, Bacillus cereus ZWB3 immobilized on a polyurethane (PUF) carrier was studied. The PUF-ZWB3 required only 20 h for the degradation of 1,500 mg L−1 of phenol, shortened by 8 h than the free bacteria. In addition, the PUF-ZWB3 could increase the degradation concentration of phenol from 1,500 to 2,000 mg L−1, and the complete degradation of 2,000 mg L−1 phenol only used 44 h. In addition, the PUF-ZWB3 showed much higher removal of phenol than the free bacteria at different pH values, salt concentrations, and heavy metal ions. Particularly, the PUF-ZWB3 could still completely remove phenol in a strongly alkaline environment, such as pH 10 and 11. In addition, the removal efficiency of phenol by PUF-ZWB3 was still 100% after 10 cycles. This study showed that the PUF immobilization system had great potential in the field of remediation of organic pollution.
The recent achievements concerning porous structures are reviewed for the applications in biomedical-related systems due to their potential in the culture, proliferation, adhesion, and differentiation of cells, inhibition and separation of bacteria.