Performance test and analysis of tetracycline degradation using a Micro-Nano Bubble system.

Antibiotics and organic residues from Tetracycline (TC) and other pharmaceuticals administered to aquatic living organism have negative impacts on aquatic environment by killing-off non-target living organisms and developing antibiotic-resistant bacteria. In this study, Micro-Nano Bubble (MNB) system was used to remove TC residues. MNB system demonstrated good level of degradation efficiency, as resulted in experiment where in time of 100 min, the TC degraded at rate of 82.66% from its initial concentration of TC when the initial concentration was 1 mg/L. When the initial concentration was increased to 10 mg/L, MNB system degraded TC at 64.35% of their initial, this means MNB system demonstrated good level of efficiency for TC removal and indicated that it is more efficient in TC degradation under the conditions of low initial TC concentration and high availability of dissolved oxygen (DO). In the system as the temperature increased there was a significant decrease in DO saturation which was related to the TC complex structure that contain multiple function groups such as amino groups, hydroxyl and carboxyl which possess high strong affinity with oxygen that leads to their adsorption onto bubble surface. This study provides significant insights into the application of MNB system for the removal of organic residues within aquatic ecosystem and underscores the need for further exploration of MNB technology for environmental remediation.

Effects of Macroautophagy and Mitophagy on the Pathogenicity of Fusarium graminearum.

Fusarium graminearum is the main pathogen of Fusarium head blight (FHB), which causes huge economic losses every year. In this study, an attempt was made to control FHB from the point of view of the physiological behavior of the pathogen itself. Autophagic inhibitors and activators were used, and the pathogenicity-related indices of F. graminearum were measured. The results showed that under nitrogen-rich conditions, macroautophagy inhibition and activation greatly reduced the mycelium weight to 0.28 and 0.25 g/ml at 24 h, which were 17.82 and 24.77% lower than that of the control treatment, respectively. Mitophagy inhibition also significantly decreased the mycelium weight (P < 0.05). Conidial yield was found to be affected by factors related to autophagy occurrence. It was found that both autophagy inhibition and activation could reduce the conidiation of F. graminearum. The toxin contents in wheat medium of macroautophagy activation treatments were 0.678, 0.190, 0.402, and 0.195 µg/g when cultured for 8 and 24 h under 0% N and 100% N conditions, respectively, which were significantly higher than those of the control treatments (P < 0.05). The infection length was measured to characterize the infectivity of F. graminearum, and we found that the length was short under macroautophagy activation conditions. However, mitophagy did not seem to affect the infectivity of F. graminearum. In summary, the above results indicate that macroautophagy and mitophagy inhibition could reduce the pathogenicity of F. graminearum, which may provide a new perspective for management of plant fungal diseases.

The Odor Release Regularity of Livestock and Poultry Manure and the Screening of Deodorizing Strains.

Human living environments and health are seriously affected by the odor produced from fermentation of livestock and poultry manure. In order to reduce the odor pollution caused by livestock and poultry manure, efficient strains were screened and two methods were tried in this study. The orthogonal test design was used to analyze the gas produced by pig manure under different conditions of temperature, time, wheat straw doping amount and calcium carbonate doping amount. Then, according to ammonia, hydrogen sulfide and comprehensive odor removal effects, the high efficiency of deodorizing strains were screened. The results showed that pig manure produced the least odor when the temperature was 20 °C, added 0% calcium carbonate, 20% wheat straw and waited for 48 h. Three strains were screened to inhibit the odor production of pig manure: Paracoccus denitrificans, Bacillus licheniformis and Saccharomyces cerevisiae, showed that their highest removal rate of ammonia and hydrogen sulfide gas could reach 96.58% and 99.74% among them; while for three strains of end-control pig manure stench: Pichia kudriavzevii, P. denitrificans and Bacillus subtilis, the highest removal rate of ammonia and hydrogen sulfide gas reached 85.91% and 90.80% among them. This research provides bacteria resources as the high-efficiency deodorizing function for the source suppression and the end treatment of the odor gas of pig manure, which has high application value for the control of odor pollution.