Vitellogenin accumulation leads to reproductive senescence by impairing lysosomal function.

The maintenance of proteostasis is essential for cellular and organism healthspan. How proteostasis collapse influences reproductive span remains largely unclear. In Caenorhabditis elegans, excess accumulation of vitellogenins, the major components in yolk proteins, is crucial for the development of the embryo and occurs throughout the whole body during the aging process. Here, we show that vitellogenin accumulation leads to reproduction cessation. Excess vitellogenin is accumulated in the intestine and transported into the germline, impairing lysosomal activity in these tissues. The lysosomal function in the germline is required for reproductive span by maintaining oocyte quality. In contrast, autophagy and sperm depletion are not involved in vitellogenin accumulation-induced reproductive aging. Our findings provide insights into how proteome imbalance has an impact on reproductive aging and imply that improvement of lysosomal function is an effective approach for mid-life intervention for maintaining reproductive health in mammals.

Unveiling organic loading shock-resistant mechanism in a pilot-scale moving bed biofilm reactor-assisted dual-anaerobic-anoxic/oxic system for effective municipal wastewater treatment.

Microbial biomass and activity are frequently subjected to organic loading shock (OLS) from decentralized municipal wastewater. A hybrid moving bed biofilm reactor-assisted dual-anaerobic-anoxic/oxic system (D-A2MBBR) was established by integrating dual-anaerobic-anoxic/oxic with moving bed biofilm reactor to resist OLS for stable nutrients removal. The D-A2MBBR achieved 91.57% of chemical oxygen demand, 93.33% of ammonia-nitrogen, 80.20% of total nitrogen and 92.68% of total phosphorus removal, respectively, under the fluctuation of organic loading rate from 417.9 to 812.0 g COD m-3 d-1. The 16S rRNA gene sequencing revealed that Gemmobacter (7.28%) was identified as dominating anoxic denitrifying genus in oxic chamber, confirming the coexistence of aerobic and anaerobic/anoxic micro-environments. This circumstance boosted simultaneous nitrification-denitrification and phosphorus removal and the microbial community evolution inside the multilayer biocarrier-attached biofilms. In general, the D-A2MBBR was able to provide unique, cooperative and robust bacterial consortia to form a buffer against OLS, and ensuring effluent stability.

A conserved klo-1-mpk-1 pathway regulates autophagy and modulates longevity in Caenorhabditis elegans.

There are six different longevity models in Caenorhabditis elegans. Previous studies have identified several convergence points, such as hlh-30, daf-16, and klf-3, required for lifespan extension in these longevity models. However, it is not clear whether there other such convergence points. In this study, based on analysis of transcriptome data, we found that the expression of klo-1/klotho was elevated in several longevity models. klo-1 was required for lifespan extension in the glp-1(e2141) and isp-1(qm150) mutants. klo-1 extended the lifespan of glp-1(e2141) and isp-1(qm150) worms by activating extracellular-signal-regulated kinase (ERK). In addition, klo-1 and mpk-1 (the homologous gene encoding ERK) regulated autophagy in glp-1(e2141) mutants, suggesting that klo-1 regulates lifespan by activating autophagy.

Evaluation of an intermittent-aeration constructed wetland for removing residual organics and nutrients from secondary effluent: Performance and microbial analysis.

This study proposed a novel intermittent-aeration constructed wetland (CW) to resolve the vertical loss of oxygen in tertiary treatment. Compared to the non-aeration CW, the intermittent-aeration CW presented a better removal performance (90.8% chemical oxygen demand, 94.3% ammonia nitrogen, 91.5% total nitrogen and 94.1% total phosphorus) at a dissolved oxygen of 3 mg L-1 and hydraulic retention time of 2 days. It was mainly attributed to the higher abundance and greater diversity of bacterial community due to the oxygen supply. High-throughput sequencing indicated that high abundance of phyla Proteobacteria (35.34%) and Bacteroidetes (18.20%) in intermittent-aeration CW were responsible for simultaneous nitrogen and phosphorus removal. Besides, the dominant families Burkholderiaceae (11.16%), Microtrichales (6.88%) and Saprospiraceae (6.50%) were also detected, which was vital to hydrolyze and utilize complex organic matters. In general, oxygen supply upregulated the metabolism pathways of amino acid and carbohydrate, bringing a greater biodegradation potential for removing contaminants.