Biologically Induced Deposition of Fine Suspended Particles by Filter-Feeding Bivalves in Land-Based Industrial Marine Aquaculture Wastewater

Industrial aquaculture wastewater contains large quantities of suspended particles that can be easily broken down physically. Introduction of macro-bio-filters, such as bivalve filter feeders, may offer the potential for treatment of fine suspended matter in industrial aquaculture wastewater. In this study, we employed two kinds of bivalve filter feeders, the Pacific oyster Crassostrea gigas and the blue mussel Mytilus galloprovincialis, to deposit suspended solids from marine fish aquaculture wastewater in flow-through systems. Results showed that the biodeposition rate of suspended particles by C. gigas (shell height: 8.67±0.99 cm) and M. galloprovincialis (shell height: 4.43±0.98 cm) was 77.84±7.77 and 6.37±0.67 mg ind⁻¹•d⁻¹, respectively. The total solid suspension (TSS) deposition rates of oyster and mussel treatments were 3.73±0.27 and 2.76±0.20 times higher than that of the control treatment without bivalves, respectively. The TSS deposition rates of bivalve treatments were significantly higher than the natural sedimentation rate of the control treatment (P<0.001). Furthermore, organic matter and C, N in the sediments of bivalve treatments were significantly lower than those in the sediments of the control (P<0.05). It was suggested that the filter feeders C. gigas and M. galloprovincialis had considerable potential to filter and accelerate the deposition of suspended particles from industrial aquaculture wastewater, and simultaneously yield value-added biological products.     

Cleavage of PrePL by Lon promotes growth and pathogenesis in Magnaporthe oryzae

ATP-dependent Lon proteases function in bacterial pathogenesis by regulating the expression of the Type III secretion system; however, little is known about how Lon proteases regulate fungal pathogenesis. We previously investigated Lon-binding proteins involved in fungal pathogenesis that interact with PrePL, the smallest Magnaporthe oryzae Lon-binding protein. Here, we show that Lon cleaves PrePL and produces Pc, an extracellular 11-kDa isoform with catalase and peroxidase activity. The ΔPrePL loss-of-function strain showed stronger sporulation and accelerated disease development, suggesting a temporally specific negative regulatory mechanism controlled by PrePL in disease progression. Neither the truncated Pc, nor the full-length PrePL missing the Lon cleavage site complemented the ΔPrePL phenotype, suggesting that full-length PrePL and Pc both function in fungal development. PrePL targeted to the mitochondria undergoes hydrolysis by Lon to produce Pc, which accumulates in the fungal apoplast. Importantly, recombinant Pc induced plant defence responses and cell death after being infiltrated into selected plant leaves, indicating that it functions as an avirulence factor. This work thus reveals a novel pathogenic factor in the fungal Lon-mediated pathway. Additionally, our results provide new insight into the functions of a full-length protein and its cleaved isoform in fungal pathogenesis.     

A Novel Mechanism for NF-κB-activation via IκB-aggregation: Implications for Hepatic Mallory-Denk-Body Induced Inflammation

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Highlights

• •Liver Mallory-Denk-Body inducers elicited an IκBα-loss and NF-κB-activation.
• •IκBα-loss was due to its sequestration into insoluble cytoplasmic aggregates.
• •Four proteomic approaches identified 10 IκBα-interacting/aggregating proteins.
• •Nup153/RanBP2-aggregation prevented IκBα nuclear entry for ending NF-κB-activation.

     

Engineering the Saccharomyces cerevisiae β-Oxidation Pathway to Increase Medium Chain Fatty Acid Production as Potential Biofuel

Fatty acid-derived biofuels and biochemicals can be produced in microbes using β-oxidation pathway engineering. In this study, the β-oxidation pathway of Saccharomyces cerevisiae was engineered to accumulate a higher ratio of medium chain fatty acids (MCFAs) when cells were grown on fatty acid-rich feedstock. For this purpose, the haploid deletion strain Δpox1 was obtained, in which the sole acyl-CoA oxidase encoded by POX1 was deleted. Next, the POX2 gene from Yarrowia lipolytica, which encodes an acyl-CoA oxidase with a preference for long chain acyl-CoAs, was expressed in the Δpox1 strain. The resulting Δpox1 [pox2+] strain exhibited a growth defect because the β-oxidation pathway was blocked in peroxisomes. To unblock the β-oxidation pathway, the gene CROT, which encodes carnitine O-octanoyltransferase, was expressed in the Δpox1 [pox2+] strain to transport the accumulated medium chain acyl-coAs out of the peroxisomes. The obtained Δpox1 [pox2+, crot+] strain grew at a normal rate. The effect of these genetic modifications on fatty acid accumulation and profile was investigated when the strains were grown on oleic acids-containing medium. It was determined that the engineered strains Δpox1 [pox2+] and Δpox1 [pox2+, crot+] had increased fatty acid accumulation and an increased ratio of MCFAs. Compared to the wild-type (WT) strain, the total fatty acid production of the strains Δpox1 [pox2+] and Δpox1 [pox2+, crot+] were increased 29.5% and 15.6%, respectively. The intracellular level of MCFAs in Δpox1 [pox2+] and Δpox1 [pox2+, crot+] increased 2.26- and 1.87-fold compared to the WT strain, respectively. In addition, MCFAs in the culture medium increased 3.29-fold and 3.34-fold compared to the WT strain. These results suggested that fatty acids with an increased MCFAs ratio accumulate in the engineered strains with a modified β-oxidation pathway. Our approach exhibits great potential for transforming low value fatty acid-rich feedstock into high value fatty acid-derived products.     

View on donated life: Construction of philosophical ethics on human organ donation

With the emergence of organ donation and donation technology, the previous indivisibility of the human body becomes divisible, and different human organs form a new life subject. With reference to specific case studies in China, a new life, consisting of donated organs from different bodies by donation, can be called “donated life.” Donated life is a win-win action between altruism and egoism, that is, to save the lives of others and to regenerate the organs of donors or their relatives. Due to the emergence of this kind of life, traditional social ethics theories based on the marriage-related family find it difficult to difficult to explain the new realities. Thus, new thinking about social ethics is necessary.     

A novel prognostic signature of immune‐related genes for patients with colorectal cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers with an estimated 1.8 million new cases worldwide and associated with high mortality rates of 881 000 CRC‐related deaths in 2018. Screening programs and new therapies have only marginally improved the survival of CRC patients. Immune‐related genes (IRGs) have attracted attention in recent years as therapeutic targets. The aim of this study was to identify an immune‐related prognostic signature for CRC. To this end, we combined gene expression and clinical data from the CRC data sets of The Cancer Genome Atlas (TCGA) into an integrated immune landscape profile. We identified a total of 476 IRGs that were differentially expressed in CRC vs normal tissues, of which 18 were survival related according to univariate Cox analysis. Stepwise multivariate Cox proportional hazards analysis established an immune‐related prognostic signature consisting of SLC10A2, FGF2, CCL28, NDRG1, ESM1, UCN, UTS2 and TRDC. The predictive ability of this signature for 3‐ and 5‐year overall survival was determined using receiver operating characteristics (ROC), and the respective areas under the curve (AUC) were 79.2% and 76.6%. The signature showed moderate predictive accuracy in the validation and GSE38832 data sets as well. Furthermore, the 8‐IRG signature correlated significantly with tumour stage, invasion, lymph node metastasis and distant metastasis by univariate Cox analysis, and was established an independent prognostic factor by multivariate Cox regression analysis for CRC. Gene set enrichment analysis (GSEA) revealed a relationship between the IRG prognostic signature and various biological pathways. Focal adhesions and ECM‐receptor interactions were positively correlated with the risk scores, while cytosolic DNA sensing and metabolism‐related pathways were negatively correlated. Finally, the bioinformatics results were validated by real‐time RT?qPCR. In conclusion, we identified and validated a novel, immune‐related prognostic signature for patients with CRC, and this signature reflects the dysregulated tumour immune microenvironment and has a potential for better CRC patient management.