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1. Effects of external recirculation on a two‐stage mainstream anaerobic‐anammox treatment system

   https://doi.org/10.1002/wer.1019  

   Li, Xiaojin ; He, Zhen ( February 2019 , Water Environment Research)

   Nitritation‐anammox treatment can be a potentially energy‐ and resource‐efficient technology for treating mainstream wastewater. However, the issue of nitrate residue from anammox treatment remains to be addressed. Herein, external recirculation of the anammox effluent to a hybrid anaerobic reactor (HAR), which was also to provide a continuous flow with lowCOD/N for the nitritation‐anammox reactor, was employed to decrease the residue compounds. The recirculation ratio of 50% was observed to be the optimal to achieve the best overall performance with potential savings in energy demand. Specifically, in the operation scenario ofR = 50%, the highestCODremoval of ~90% by theHARwas achieved. Meanwhile, the lowestCOD/NH₄⁺‐N ratio of ~2.0 in theHAReffluent ensured the lowest observedNO₃⁻‐N/NH₄⁺‐N ratio of ~14% in the nitritation‐anammox reactor. These results have demonstrated the feasibility of applying external recirculation for nitrate residue removalviadenitrification in the anaerobic pretreatment stage.

   Nitritation‐anammox treatment is an attractive method for mainstream wastewater treatment.

   Nitrate residue from anammox processes contributes to total nitrogen in the final effluent.

   Recirculation of anammox effluent to an anaerobic reactor can decrease nitrate residue.

   A recirculation ratio of 50% results in a low COD/NH₄⁺ratio of 2 that benefits the subsequent anammox.

    

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2. Microbiomes and Planctomycete diversity in large-scale aquaria habitats

   https://doi.org/10.1371/journal.pone.0267881  

   Elbon, Claire E. ; LeCleir, Gary R. ; Tuttle, Matthew J. ; Jurgensen, Sophie K. ; Demas, Thomas G. ; Keller, Christian J. ; Stewart, Tina ; Buchan, Alison ( May 2022 , PLOS ONE)

   Senko, John M. (Ed.)

   In commercial large-scale aquaria, controlling levels of nitrogenous compounds is essential for macrofauna health. Naturally occurring bacteria are capable of transforming toxic nitrogen species into their more benign counterparts and play important roles in maintaining aquaria health. Nitrification, the microbially-mediated transformation of ammonium and nitrite to nitrate, is a common and encouraged process for management of both commercial and home aquaria. A potentially competing microbial process that transforms ammonium and nitrite to dinitrogen gas (anaerobic ammonium oxidation [anammox]) is mediated by some bacteria within the phylum Planctomycetes. Anammox has been harnessed for nitrogen removal during wastewater treatment, as the nitrogenous end product is released into the atmosphere rather than in aqueous discharge. Whether anammox bacteria could be similarly utilized in commercial aquaria is an open question. As a first step in assessing the viability of this practice, we (i) characterized microbial communities from water and sand filtration systems for four habitats at the Tennessee Aquarium and (ii) examined the abundance and anammox potential of Planctomycetes using culture-independent approaches. 16S rRNA gene amplicon sequencing revealed distinct, yet stable, microbial communities and the presence of Planctomycetes (~1–15% of library reads) in all sampled habitats. Preliminary metagenomic analyses identified the genetic potential for multiple complete nitrogen metabolism pathways. However, no known genes diagnostic for the anammox reaction were found in this survey. To better understand the diversity of this group of bacteria in these systems, a targeted Planctomycete-specific 16S rRNA gene-based PCR approach was used. This effort recovered amplicons that share <95% 16S rRNA gene sequence identity to previously characterized Planctomycetes, suggesting novel strains within this phylum reside within aquaria.

    

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3. Advanced age protects resistance arteries of mouse skeletal muscle from oxidative stress through attenuating apoptosis induced by hydrogen peroxide

   https://doi.org/10.1113/JP278255  

   Norton, Charles E. ; Sinkler, Shenghua Y. ; Jacobsen, Nicole L. ; Segal, Steven S. ( July 2019 , The Journal of Physiology)

   Vascular oxidative stress increases with advancing age.

   We hypothesized that resistance vessels develop resilience to oxidative stress to protect functional integrity and tested this hypothesis by exposing isolated pressurized superior epigastric arteries (SEAs) of old and young mice to H₂O₂.

   H₂O₂‐induced death was greater in smooth muscle cells (SMCs) than endothelial cells (ECs) and lower in SEAs from oldvs. young mice; the rise in vessel wall [Ca²⁺]_iinduced by H₂O₂was attenuated with ageing, as was the decline in noradrenergic vasoconstriction; genetic deletion of IL‐10 mimicked the effects of advanced age on cell survival.

   Inhibiting NO synthase or scavenging peroxynitrite reduced SMC death; endothelial denudation or inhibiting gap junctions increased SMC death; delocalization of cytochrome C activated caspases 9 and 3 to induce apoptosis.

   Vascular cells develop resilience to H₂O₂during ageing by preventing Ca²⁺overload and endothelial integrity promotes SMC survival.

   Advanced age is associated with elevated oxidative stress and can protect the endothelium from cell death induced by H₂O₂. Whether such protection occurs for intact vessels or differs between smooth muscle cell (SMC) and endothelial cell (EC) layers is unknown. We tested the hypothesis that ageing protects SMCs and ECs during acute exposure to H₂O₂(200 µm, 50 min). Mouse superior epigastric arteries (SEAs; diameter, ∼150 µm) were isolated and pressurized to 100 cmH₂O at 37˚C. For SEAs from young (4 months) mice, H₂O₂killed 57% of SMCs and 11% of ECs in malesvs. 8% and 2%, respectively, in females. Therefore, SEAs from males were studied to resolve the effect of ageing and experimental interventions. For old (24 months) mice, SMC death was reduced to 10% with diminished accumulation of [Ca²⁺]_iin the vessel wall during H₂O₂exposure. In young mice, genetic deletion of IL‐10 mimicked the protective effect of ageing on cell death and [Ca²⁺]_iaccumulation. Whereas endothelial denudation or gap junction inhibition (carbenoxolone; 100 µm) increased SMC death, inhibiting NO synthase (l‐NAME, 100 µm) or scavenging peroxynitrite (FeTPPS, 5 µm) reduced SMC death along with [Ca²⁺]_i. Despite NO toxicity via peroxynitrite formation, endothelial integrity protects SMCs. Caspase inhibition (Z‐VAD‐FMK, 50 µm) attenuated cell death with immunostaining for annexin V, cytochrome C, and caspases 3 and 9 pointing to induction of intrinsic apoptosis during H₂O₂exposure. We conclude that advanced age reduces Ca²⁺influx that triggers apoptosis, thereby promoting resilience of the vascular wall during oxidative stress.

    

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4. Discovery of mosquitocides from fungal extracts through a high-throughput cytotoxicity-screening approach

   https://doi.org/10.1186/s13071-021-05089-3  

   Jin, Liang ; Niu, Guodong ; Guan, Limei ; Ramelow, Julian ; Zhan, Zhigao ; Zhou, Xi ; Li, Jun ( December 2021 , Parasites & Vectors)

   Mosquitoes transmit a variety of diseases. Due to widespread insecticide resistance, new effective pesticides are urgently needed. Entomopathogenic fungi are widely utilized to control pest insects in agriculture. We hypothesized that certain fungal metabolites may be effective insecticides against mosquitoes.

   A high-throughput cytotoxicity-based screening approach was developed to search for insecticidal compounds in our newly established global fungal extract library. We first determined cell survival rates after adding various fungal extracts. Candidate insecticides were further analyzed using traditional larval and adult survival bioassays.

   Twelve ethyl acetate extracts from a total of 192 fungal extracts displayed > 85% inhibition of cabbage looper ovary cell proliferation. Ten of these 12 candidates were confirmed to be toxic toAnopheles gambiaeSua5B cell line, and six showed > 85% inhibition ofAnophelesmosquito cell growth. Further bioassays determined a LC₅₀, the lethal concentration that kills 50% of larval or adult mosquitoes, of 122 µg/mL and 1.7 µg/mosquito, respectively, after 24 h for extract 76F6 fromPenicillium toxicarium.

   We established a high-throughput MTT-based cytotoxicity screening approach for the discovery of new mosquitocides from fungal extracts. We discovered a candidate extract fromP. toxicariumthat exhibited high toxicity to mosquito larvae and adults, and thus were able to demonstrate the value of our recently developed approach. The active fungal extracts discovered here are ideal candidates for further development as mosquitocides.

    

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5. Antifeedant, contact toxicity and oviposition deterrent effects of phyllostine acetate and phyllostine isolated from the endophytic fungus Diaporthe miriciae against Plutella xylostella larvae

   https://doi.org/10.1002/ps.5673  

   Ratnaweera, Pamoda B. ; M Jayasundara, J. M. Nisansala ; Herath, H. H. M. Suseema D. ; Williams, David E. ; Rajapaksha, Sasini U. ; Nishantha, K. M. D. W. Prabath ; de Silva, E. Dilip ; Andersen, Raymond J. ( December 2019 , Pest Management Science)

   Larvae of the diamond back moth (DBM),Plutella xylostella, are destructive cabbage pests causing economic losses worldwide. Continuous application of synthetic pesticides to control this pest has resulted in environmental pollution and resistant pest strains. Thus, there is a crucial need to seek natural alternatives with minimal detrimental effects. This study was designed to investigate the antifeedant activities of endophytic fungi ofCyperus iriaand to determine the antifeedant, contact toxicity and oviposition deterrent activities of phyllostine acetate and phyllostine of the endophyticDiaporthe miriciaefungus.

   Two cyclohexeneoxidediones, phyllostine acetate (1) and phyllostine (2), isolated from an ethyl acetate extract ofD. miriciaeexhibited strong antifeedant, contact toxicity, and oviposition deterrent activities againstP. xylostella. Phyllostine acetate (1) and phyllostine (2) showed feeding deterrent indexes of 100% at 50 μg cm⁻²in the no‐choice leaf disc assay and 50% feeding deterrence (DC₅₀) values of 9 and 4.7 μg cm⁻²respectively. The median lethal concentration (LC₅₀) values of phyllostine acetate (1) and phyllostine (2) were 4.38 and 6.54 μg/larva in the contact toxicity assay. The oviposition deterrent indexes of the two compounds were 100% for phyllostine acetate (1) and 28.6% for phyllostine (2) at 50 μg cm⁻².

   Phyllostine acetate and phyllostine show promise as compounds for the control ofP. xylostella. This study encourages further investigation of endophytic fungi of the family Cyperacea, for the development of natural pest control agents in agriculture. © 2019 Society of Chemical Industry

    

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