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This study investigated the performance of anaerobic digestion systems using four types of fibrous biofilm carriers, a polypropylene, a polyester, a polyamide, and a polyurethane fiber material. The biogas and methane production, pH, chemical oxygen demand, total solids content, volatile solids content, residual coenzyme F 420 , and microbial community compositions were determined during the experimental runs. Furthermore, scanning electron microscopy was employed to identify the microbial consortium and examine their attachment onto the surface of the four fibrous biofilm carriers. The polypropylene fiber system maintained the highest biogas and methane production in the reactor, which was 44.80% and 49.84% higher than that noted in the control, respectively, during the entire anaerobic fermentation cycle. Meanwhile, the polypropylene fiber system exhibited the highest TS, VS, and COD removal efficiency. The results of high-throughput sequencing indicated that the dominant species in the polypropylene fiber system were Methanoregula and Methanobacterium., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

To investigate the phenotypic characteristics of the strain of the rabies virus CTNCEC25, the strain of the China rabies virus CTN-1 adapted to primary chicken embryo cells (CECs), Vero cells, and mouse neuroblastoma N2a cells was inoculated with CTNCEC25 and parental CTN-1 strains to explore the cytopathic effect (CPE) and growth kinetics of CTNCEC25 on cultured cells. To determine the pathogenicity of CTNCEC25, suckling mice, adult mice, guinea pigs and rabbits were inoculated with CTNCEC25 via the intracerebral route and their survival monitored every day. Furthermore, the CTNCEC25 strain was passed serially in CECs for 20 passages and then 3 passages in the brains of suckling mice to determine phenotypic stability. CTNCEC25 achieved similar growth kinetics in Vero cells and N2a cells compared with parental CTN-1, but CTNCEC25 replicated more efficiently in CECs than the CTN-1 strain with a titer 72 h after infection reaching 10(7.5-7.6) FFU/mL, which was significantly higher than the 10(5.8) FFU/mL achieved by its parental strain, CTN-1. Moreover, CTNCEC25 induced apparent CPE in Vero cells, CECs and N2a cells. Analyses of intracerebral inoculation demonstrated that CTNCEC25 was attenuated profoundly in adult mice and was completely apathogenic to guinea pigs and rabbits, though it caused death in suckling mice. The CTNCEC25 strain proliferated steadily after serial passage in CECs and the brains of suckling mice, and remained avirulent in adult mice. These results suggest that CTNCEC25 is a highly attenuated and genetically stable strain of the rabies virus. CTNCEC25 replicated stably and efficiently in cultured cells and achieved high titers, so it could be a promising and safe vaccine strain for rabies prevention in China.

During the startup of a full-scale anoxic/aerobic (A/O) biological treatment plant for acrylonitrile wastewater, the removal efficiencies of NH(3)-N and total Kjeldahl nitrogen (TKN) were 1.29 and 0.83% on day 30, respectively. The nitrification process was almost totally inhibited, which was mainly caused by the inhibitory effects of toxic compounds. To eliminate the inhibition, cultivating the bacteria that degrade toxic compounds with patience was applied into the second startup of the biological treatment plant. After 75 days of startup, the inhibitory effects of the toxic compounds on nitrification were eliminated. The treatment plant has been operated stably for more than 3 years. During the last 100 days, the influent concentrations of chemical oxygen demand (COD), NH(3)-N, TKN and total cyanide (TCN) were 831-2,164, 188-516, 306-542 and 1.17-9.57 mg L(-1) respectively, and the effluent concentrations were 257 ± 30.9, 3.30 ± 1.10, 31.6 ± 4.49 and 0.40 ± 0.10 mg L(-1) (n = 100), respectively. Four strains of cyanide-degrading bacteria which were able to grow with cyanide as the sole carbon and nitrogen source were isolated from the full-scale biological treatment plant. They were short and rod-shaped under scanning electron microscopy (SEM) and were identified as Brevundimonas sp., Rhizobium sp., Dietzia natronolimnaea and Microbacterium sp., respectively.

GAC/O3 (ozonation in the presence of granular activated carbon) combined with enhanced coagulation was employed to process biotreated textile wastewater for possible reuse. The doses of ozone, GAC and coagulant were the variables studied for optimization. The effects of different treatment processes on effluent organic matter (EfOM) characteristics, including biodegradability, hydrophobic and hydrophilic nature, and apparent molecular weight (AMW) distribution were also investigated. Compared with ozonation, GAC/O3 not only presented a higher pre-oxidation efficiency, but also improved the treatability of hydrophobic and high molecular weight compounds by enhanced coagulation. After treatment by GAC/O3 pre-oxidation (0.6 mg O3 x mg(-1) COD and 20 g x L(-1) GAC) and enhanced coagulation (25 mg x L(-1) Al3+ at pH 5.5), the removal efficiencies of chemical oxygen demand (COD), dissolved organic carbon (DOC) and colour were higher than those for coagulation alone by 17.3%, 12.0% and 25.6%, respectively. Residual organic matter consisted mainly of hydrophobic acids and hydrophilic compounds of AMW < 1 kDa, which were colourless and of limited biological availability. The combination of GAC/O3 and enhanced coagulation was proved to be a simple and effective treatment strategy for removing EfOM from biotreated textile wastewater.

Objective: To identify the relationship between salicylate 5-hydroxylase activity and the degradation rate of phenanthrene by moderately halophilic Martelella sp. AD-3, and to investigate their enzymatic characteristics., Methods: The products resulted from degradation of salicylic acid using the crude enzyme produced by AD-3 was analyzed using HPLC analysis, and salicylate 5-hydroxylase activities at different conditions was calculated according to the change of NADH absorbance at 340 nm., Results: The salicylate 5-hydroxylase activity was higher during log-phase and early stationary phase of AD-3, and the enzyme activity was in consistent with phenanthrene degradation rate. The enzyme production was induced by phenanthrene and salicylic acid. The highest enzyme activity, 132.8 nmol/(min x mg), from strain AD-3 was obtained under the phenanthrene concentration of 200 mg/L, 3% salinity and a pH of 9.0. The optimum conditions for degradation of salicylic acid using this enzyme were 30 degrees C , pH 7.5, and salinity 3%. The V(max) and K(m) for the enzyme were 200 nmol/(min x mg) and 8.7 micromol/L, respectively., Conclusion: The salicylate 5-hydroxylase was produced in the degradation of phenanthrene in AD-3. The enzyme activity was related to phenanthrene degradation rate.

The association between community functional shift and dynamics of genomic DNA composition can be used to identify functionally relevant populations as indicator organisms for systems monitoring. In this work, fingerprinting-based community DNA hybridization was used to monitor community structural dynamics and identify genomic fragments whose abundance shifts were concomitant to changes in COD removal capacity in a reactor. A laboratory-scale anaerobic-anoxic-oxic fixed biofilm system treating coking wastewater was operated with (LR mode) or without effluent recirculation (LNR mode). The contribution to total chemical oxygen demand (COD) removal by the anoxic reactor increased from 4% in LNR mode to 26% in LR mode. Long primer RAPD (randomly amplified polymorphic DNA) community fingerprints of the anoxic reactor also changed most significantly from the one similar to the anaerobic reactor to one similar to the oxic reactor. DNA hybridization revealed one signature band of 2.1 kb shared by the anoxic and oxic reactors in LR, but not LNR mode. Clone library profiling of this band resulted in one predominant 2.1-kb genomic fragment (B3) with no homologous sequences in GenBank. Real-time polymerase chain reaction indicated that copy numbers of B3 in the anoxic reactor under LR mode were 69 times higher than that under LNR mode, concomitant to a significant increase in COD removal capacity in this reactor. The different patterns of distribution of B3 in the laboratory system and a comparable malfunctioning industrial system demonstrated the potential of this genomic fragment as physical markers in systems monitoring. In addition, this genomic fragment may allow sequence-guided isolation of the host microbe.