With the great extension of the human lifespan in recent times, many aging diseases have inevitably followed. Dementia is one of the most-commom neurodegenerative aging diseases, in which inflammation-related Alzheimer’s disease (AD) is the most prevalent cause of dementia. Amyloid accumulation in the brain, which occurs before any clinical presentations, might be the first and key step in the development of AD. However, many clinical trials have attempted to remove amyloid from brains of AD patients, but none has so far been successful. Negatively charged plasmon-activated water (PAW) is created by resonantly illuminated gold (Au) nanoparticles (NPs), which reduce the hydrogen-bonded (HB) structure of water. PAW was found to possess anti-oxidative and anti-inflammatory effects. Herein, we report on an innovative strategy to retard the progression of AD by the daily consumption of PAW instead of normal deionized (DI) water. APPswe/PS1dE9 transgenic mice were treated with PAW or DI water from the age of 5 months for the next 9 months. Encouragingly, compared to DI water-treated mice, mice treated with PAW presented better memory performance on a test of novel object recognition and had a significantly lower amyloid burden according to 18F-florbetapir amyloid-PET and phosphorylated (p)-tau burden according to Western blotting and immunohistochemistry measurements. There were no obvious side effects in PAW-treated mice. Collectively, our findings support that PAW was able to reduce the amyloid and p-tau burden and improve memory in an AD mouse model. However, the protein levels of molecules involved in amyloid metabolism and oligomeric amyloid did not change. We propose that the effects of PAW of reducing the amyloid burden and improving memory function cannot be attributed to synthesis/degradation of amyloid-βprotein but probably in preventing aggregation of amyloid-β proteins or other mechanisms, including anti-inflammation. Further applications of PAW in clinical trials to prevent the progression of AD are being designed.

Although bacteria with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity have been used to mitigate biotic and abiotic stresses in crops, it is not well known whether the ACC deaminase gene (acdS) in Pseudomonas azotoformans is related to the alleviation of salt stress by the bacterium. This study aimed to evaluate the effects of acdS in P. azotoformans strain CHB 1107 on the nutrient uptake and growth of tomato plants under salt stress. The acdS mutant (CHB 1107 M) of P. azotoformans CHB 1107 was obtained through bacterial conjugation. Wild-type (CHB 1107 WT) and CHB 1107 M were used to inoculate tomato plants grown in a soil or solution with an electrical conductivity of 6 dS/m adjusted by NaCl. CHB 1107 M completely lost the ability to produce ACC deaminase, whereas the complementation of acdS in CHB 1107 M preserved its ACC deaminase activity. CHB 1107 WT significantly reduced the production of ethylene and proline by tomato plants under salt stress, increasing the shoot and root dry weights of tomato plants compared with the noninoculated control and CHB 1107 M. In addition, tomato plants inoculated with CHB 1107 M showed a significant reduction in K (27.5%), Ca (23.0%), and Mn uptake (17.5%) compared with those inoculated with CHB 1107 WT. In contrast, CHB 1107 WT significantly reduced Na uptake by tomato plants in comparison to CHB 1107 M in saline soil conditions. In addition, the inoculation of tomato plants with CHB 1107 WT resulted in a higher K/Na ratio than in those inoculated with CHB 1107 M and the noninoculated control. These findings suggest that acdS in P. azotoformans is associated with the amelioration of salinity stress in tomato. Plant transformation with acdS and the field application of P. azotoformans may be used as potential management tools for crops under salt stress.

Trehalose is a nonreducing disaccharide and has a wide range of applications in food and biorelated industry. This sugar can be synthesized from maltose in one step by trehalose synthase. In this study, we attempted to overproduce trehalose synthase from Picrophilus torridus (PTTS), a thermoacidophilic archaea, in Escherichia coli . However, overproduction of PTTS was hampered when the T7 promoter-driven PTTS gene (PT7-PTTS) on a multicopy plasmid was employed in E. coli . The factors limiting PTTS production were identified in a systematic way, including the codon bias, plasmid instability, a redundant gene copy, a high basal level of PTTS, and metabolic burden resulting from the mutlicopy plasmid DNA and antibiotics. To overcome these difficulties, an E. coli strain was developed with insertion of PT7-PTTS into the chromosome and enhanced expression of genomic argU tRNA and ileX tRNA genes. Without the selective pressure, the constructed producer strain was able to produce a stable and high-level production of recombinant PTTS. Overall, we proposed a simple and effective method to address the issue that is most commonly raised in overproduction of heterologous proteins by E. coli .

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The overuse of chemical fertilizers deteriorates soil quality, and the application of organic amendments has been proposed as an alternative to mineral fertilizers. This study aimed to investigate the effects of organic amendment types on soil properties, the soil microbiome, and tomato growth. Tomato seedlings were grown in soils applied with ten fertilizer treatments, including a no fertilization control, a chemical fertilization control, and eight organic amendment treatments. Compared with the chemical fertilization treatment, the application of manure compost significantly increased the shoot dry weight of tomato plants. In addition, manure compost and tea seed meal remarkably increased soil organic matter (SOM) in comparison with the no fertilization and chemical fertilization treatments. Moreover, manure compost significantly increased soil-exchangeable K and Mg. The application of neem cake and manure compost significantly increased both bacterial diversity and richness. The relative abundance of Lysinibacillus was significantly positively related to the shoot and total dry weights of tomato plants, and its relative abundance was positively influenced by SOM and soil-exchangeable K. Overall, the manure compost used in this study can increase SOM, soil-exchangeable K and Mg, and the relative abundance of Lysinibacillus, consequently promoting tomato growth.