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Sludge anaerobic digestion promoted by enzymes has the advantages of mild reaction, high efficiency and environmental protection etc. However, the difficulty of recovery and poor catalytic stability seriously restrict its application. Enzyme immobilization is the key to solve the above problems. A new type of polyvinyl alcohol(PVA) carrier was prepared by Noria and polyethylenimide(PEI) co-deposition. The effect of lysozyme immobilized with Noria-PEI modified PVA carriers on the efficiency of sludge anaerobic fermentation for VFAs production was studied. The results showed that immobilized lysozyme could enhance sludge fermentation to promote SCOD, and SCOD reached the highest concentration of 2 892.4 mg/L within 36 h, which was 3.4 times higher than in the blank(day 6). VFAs concentration peaked at 2 130.8 mg/L on day 4, mainly comprised of acetic acid and propionic acid, accounting for 61.8%-80.7%. The average particle size and specific surface area of sludge in the immobilized enzyme system were 42.957 μm and 0.413 m2/g, indicating that immobilized enzyme enhanced the hydrolysis of granular sludge. Microbial community analysis showed that the hydrolytic acid-producing phyla of Firmicutes, Proteobacteria and Bacteroides accounted for high proportion in the immobilized enzyme system. At the genus level, Macellibacteroides, Petrimona, Lactobacillu, and Clostridium_sensu_stricto_1 were the main genera, which revealed the mechanism of enhanced VFAs production by the immobilized enzyme at microscopic level.

The offshore completion fluid has the characteristics of complex composition and high salinity. In order to solve the severe corrosion of underground pipelines causing by completion fluid. In this paper，a polyamide chitosan（PACS） was synthesized from the natural polysaccharide chitosan，and its corrosion inhibition performance on carbon steel was investigated. The results of weight loss corrosion experiments showed that after adding 2 000 mg/L polyamide chitosan to the completion fluid at 80 ℃，the corrosion rate of carbon steel decreased from 3.852 to 0.072 mm/a，and the corrosion inhibition percentage was 98.13%. In addition，electrochemical tests（potentiodynamic polarization and Nyquist curve） also showed that when the concentration of PACS reached 2 000 mg/L，the corrosion inhibition percentages was more than 90%. PACS shows good corrosion inhibition properties of carbon steel.

To tune the complexation and solvent extraction performance of the ligands with a 1,10-phenanthroline core for trivalent actinides (An3+) and lanthanides (Ln3+), we synthesized two new asymmetric tetradentate ligands with pyrazole and amide groups, i.e., L1 (N,N-diethyl-9-(5-ethyl-1H-pyrazol-3-yl)-1,10-phenanthroline-2-carboxamide) and its analogue L2 with longer alkyl chains (N,N-dihexyl). The complexation of the ligands with Ln3+ was confirmed by 1H NMR titration and X-ray crystallography, and stability constants were measured in methanol by spectrophotometric titration. The asymmetric ligands exhibited an improved performance in terms of selective solvent extraction of Am3+ over Eu3+ in strongly acidic solutions compared to their symmetric analogues. The improved selectivity of the asymmetric ligands was interpreted theoretically by density functional theory simulations. This study implies that combining different functional groups to construct asymmetric ligands may be an efficient way to tune ligand performance with regard to An3+ separation from Ln3+. [ABSTRACT FROM AUTHOR]

Background The blue catfish is of great value in aquaculture and recreational fisheries. The F1 hybrids of female channel catfish (Ictalurus punctatus) × male blue catfish (Ictalurusfurcatus) have been the primary driver of US catfish production in recent years because of superior growth, survival, and carcass yield. The channel–blue hybrid also provides an excellent model to investigate molecular mechanisms of environment-dependent heterosis. However, transcriptome and methylome studies suffered from low alignment rates to the channel catfish genome due to divergence, and the genome resources for blue catfish are not publicly available. Results The blue catfish genome assembly is 841.86 Mbp in length with excellent continuity (8.6 Mbp contig N50, 28.2 Mbp scaffold N50) and completeness (98.6% Eukaryota and 97.0% Actinopterygii BUSCO). A total of 30,971 protein-coding genes were predicted, of which 21,781 were supported by RNA sequencing evidence. Phylogenomic analyses revealed that it diverged from channel catfish approximately 9 million years ago with 15.7 million fixed nucleotide differences. The within-species single-nucleotide polymorphism (SNP) density is 0.32% between the most aquaculturally important blue catfish strains (D&B and Rio Grande). Gene family analysis discovered significant expansion of immune-related families in the blue catfish lineage, which may contribute to disease resistance in blue catfish. Conclusions We reported the first high-quality, chromosome-level assembly of the blue catfish genome, which provides the necessary genomic tool kit for transcriptome and methylome analysis, SNP discovery and marker-assisted selection, gene editing and genome engineering, and reproductive enhancement of the blue catfish and hybrid catfish. [ABSTRACT FROM AUTHOR]

A lab-scale fluidized bed bioreactor with high-density polyethylene as biofilm carrier media was operated to study partial nitrification (PN) performance with high ammonia concentrations. The system was run at nitrogen loading rates (NLRs) from 1.2 to 4.8 kg N/(m3 d) with empty bed contact time of 2.0 and 2.7 h and four different influent ammonia concentrations of 100, 200, 300 and 400 mg/L. Dissolved oxygen concentration and temperature were maintained around 1.3 mg/L and 35°C, respectively. Stable PN was successfully achieved during the whole period with low effluent NO3-N concentration at less than 15 mg/L, due to effective suppression of nitrite-oxidizing bacteria activity at high concentrations of free ammonia (5.3-27.3 mg N/L) and low alkalinity-to-ammonia ratio. At the NLR of 3.6 kg N/(m3 d), NH4-N conversion and NO2-N accumulation ratios were 57.8% and 53.9%, respectively, which could be further used in the anaerobic ammonium oxidation process (ANAMMOX) as the effluent NO2-N/NH4-N ratio was 1.27. [ABSTRACT FROM AUTHOR]