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Phenylalanine ammonia-lyase (PAL), the first enzyme of phenylpropanoid pathway, is always encoded by multigene families in plants. In this study, using genome-wide searches, 13 PALgenes in cucumber (CsPAL1–13) and 13 PALs in melon (Cm-PAL1–13) were identified. In the corresponding genomes, ten of these PALgenes were located in tandem in two clusters, while the others were widely dispersed in different chromosomes as a single copy. The protein sequences of CsPALs and CmPALs shared an overall high identity to each other. In our previous report, 12 PALgenes were identified in watermelon (ClPAL1–12). Thereby, a total of 38 cucurbit PALmembers were included. Here, a comprehensive comparison of PALgene families was performed among three cucurbit plants. The phylogenetic and syntenic analyses placed the cucurbit PALs as 11 CsPAL-CmPAL-ClPAL triples, of which ten triples were clustered into the dicot group, and the remaining one, CsPAL1-CmPAL8-ClPAL2, was grouped with gymnosperm PALs and might serve as an ancestor of cucurbit PALs. By comparing the syntenic relationships and gene structure of these PALgenes, the expansion of cucurbit PALfamilies might arise from a series of segmental and tandem duplications and intron insertion events. Furthermore, the expression profiling in different tissues suggested that different cucurbit PALs displayed divergent but overlapping expression profiles, and the CsPAL-CmPAL-ClPALorthologs showed correlative expression patterns among three cucurbit plants. Taken together, this study provided an extensive description on the evolution and expression of cucurbit PALgene families and might facilitate the further studies for elucidating the functions of PALs in cucurbit plants.

Treatment of actual coking wastewater considered to be difficult by traditional systems. The present study is related to treatment of actual coking wastewater through microaerobic EGSB reactor. The study showed the EGSB reactor could attain about 75% high COD removal. Increasing Vup could strength COD removal. Moreover, high sludge concentration and profound communal synergism existing within the dense granules were very important. As a result of the kinetic analysis of the EGSB reactor treating actual coking wastewater for COD removal using a modified Stover–Kincannon model, the maximum substrate utilization rate, vmax, half saturation constant, KS, inhibitor constant, KI, actual pollutant removal rate, , and the actual inhibition degree, KS /KI were determined as 2.65×10-3h-1, 39.57mg.L-1, 415.82mg.L-1, 6.7×10-5h-1.mg-1.L and 0.1(before increasing Vup), 7.34×10-3h-1, 19.53mg.L-1, 197.76mg.L-1, 3.7×10-4 h-1.mg-1.L and 0.1(after increasing Vup), and 9.35×10-3h-1, 6.38mg.L-1, 162.81mg.L-1, 1.47×10-3 h-1.mg-1.L and 0.04 (after increasing Vup and X), respectively. The inhibition of toxic contaminants in the actual coking wastewater would cause the decreasing of pollutant removal rate, however, enhancing and X (simultaneously optimizing sludge aggregate structure) could strengthen the performance effect.

To investigate the possibility of simultaneous high efficient removal of COD and NH3-N in the actual coking wastewater through micro-aerobic granular bio-film reactor, two-stage granular bio-film reactor system (EGSBI+ EGSBII) were continuously operated through two effluent recirculation ways for about 5 months: ERW1(24L.h-1 self-recirculation) and ERW2(15 L.h-1 self-recirculation +15 L.h-1 crossed recirculation). Compared with ERW1, through using ERW2, the two-stage EGSB reactor system could attain high COD and NH3-N removal efficiencies (86.7%-96.9% and 48.6%-80.4%) and low effluent NO2- and NO3- concentrations (0-25mg.L-1 and 7-71mg.L-1). Using ERW1, the two-stage EGSB reactor system melt with difficult of NO2- accumulation in the EGSBII (accompanied with low NH3-N removal of only 41.4%). Using ERW2, the difficult of accumulation in the EGSBII was solved and simultaneously high efficient removal of NH3-N and NO2- in the EGSBI was achieved.

To investigate the removal of thiocyanate () in the actual coking wastewater through granular bio-film reactor, two lab-scale granular bio-film reactors (EGSB reactor) (RA and RB) were continuously operated at three stages for about 16 months: anaerobic vs. micro-aerobic for EGSB reactor, varied influent concentrations and varied shock-loading (abrupt and gradual shock-loading) for micro-aerobic EGSB reactor. Compared with anaerobic operation condition, micro-aerobic operation conditions could distinctly strengthen average removal in the EGSB reactor treating actual coking wastewater (47.8% vs.5.3%). At micro-aerobic operation conditions (only with 2000-5000ml·min-1 air flow rate in the external aeration column), with 12h HRT and varied influent concentrations of 200-540mg·L-1, the EGSB reactor could always keep very high removal of 87.6%-94.1%. Microaerobic EGSB reactor had very strong ability of supporting load shock. During the whole operation stage of continuous loads shock (for about 60 days)(from 0.32kgSCN·m-3·d-1 to 1.08 kgSCN·m-3·d-1), removal ability showed a constantly increasing tendency. Micro-aerobic EGSB reactor was a simple and high effectively treatment strategy for the in the actual coking wastewater, and meanwhile high COD, ammonia, phenol and cyanide removal was also kept in the micro-aerobic EGSB reactor.

To strengthen the COD removal from actual coking wastewater, a lab-scale granular bio-film reactor was continuously operated at three stages for about 9 months: anaerobic vs. micro-aerobic (over 2 months), with and without supplement of bicarbonate (over 2 months), and with and without supplement of diatomite (about 4 months).Compared with anaerobic condition, the micro-aerobic operation could strengthen COD removal in the actual coking wastewater and increase COD removal efficiency from 21.4% to 36.4%. At micro-aerobic operation conditions, the supplement of 3g.Linfluent-1 bicarbonate could distinctly increase COD average removal efficiency from 32.9% to 65.3%, and the supplement of 6g·L-1·d-1 diatomite could significantly increase COD average removal efficiency from 33.1% to 78.1%. The supplement of bicarbonate or diatomite for the granular bio-film reactor must be an effective way for the treatment of actual coking wastewater.

Coupled anaerobicaerobic granular bio-film reactor was employed to acclimatize the granules when treating actual coking wastewater. Two oxygenation methods (i.e. A and B) were employed. For method A, dissolved O2 was supplied to the reactor A (RA) through a continuous oxygenation way of 800-15000mlmin-1. And for method B, dissolved O2 of 800-15000mlmin-1 (18-12 times at 20-60min intervals, 1 h each time) was supplied to the reactor B (RB). The experimental results showed that it took only about 6 months for granules acclimation using actual coking wastewater. With inorganic carbon (NaHCO3) addition, both oxygenation methods could run well when acclimatizing the granules. However, method A could have comparatively high and stable operation effect. And the continuous oxygenation way was more suitable for the acclimation of the granules when treating actual coking wastewater than the intermittent oxygenation way.

To accomplish rapidly the granulation process of digestion sludge for the treatment of actual coking wastewater and meanwhile achieve high COD, phenol, SCN- and CN- removal, the EGSB reactor was employed with two operation stages. StageI: Granular sludge was formed from digestion sludge using brewery wastewater as substrate in the anaerobic way (meanwhile adding little granules, which were 1/7 of the total biomass). StageII: Granular sludge was acclimatized with the actual coking wastewater through continuous micro-oxygenation way. The experimental results showed that the granular sludge could quickly form in 10d in the EGSB reactor seeded with digestion sludge and little loose granules. It took only about 6 months for the successful micro-aerobic acclimating of the granular sludge by the actual coking wastewater. The removal efficiencies of COD, phenol, SCN- and CN- were 72.9, 99.5, 95.7 and 97.5%, respectively, at 12.1h hydraulic retention time (HRT) and for 631-922, 12.8-37.7, 66.7-232.7 and 0.3-57.8mg.L-1 influent COD, phenol, SCN- and CN- concentration.

Treatment of actual domestic wastewater at ambient temperature, even low temperature is considered to be difficult by traditional systems. The present study is related to treatment of actual domestic wastewater in an EGSB reactor. The study showed the effectiveness of biological treatment of actual domestic wastewater involving appropriate microorganism and granules in an EGSB reactor. At 26℃, the reactor was operated at 18.7kg COD.m−3.d−1 of average organic loading and 83% high COD removal efficiency, and even at the highest loading rate of 57.12kgCOD.m−3.d−1, the COD removal efficiency still could attain to 68%. Varied influent flow need to supply varied optimal and thus to ensure the optimal removal effect. Low temperature would cause pollutant removal rate decrease. However, enhancing could optimize the contact of sludge and wastewater and thus strengthen the performance effect. Modified Stover–Kincannon model was applied to data obtained from experimental studies in EGSB reactor. Treatment efficiencies of the reactor were investigated at different hydraulic retention times (0.5-1.3h) and different operation temperature (15℃, 26℃). The modified Stover–Kincannon model was best fitted to the EGSB reactor, and the substrate utilization rate( ), saturation constant value( ), and actual pollutant removal rate( ) were found to be , , and for 26℃, , , and for 15℃( before increasing ), and , , and for 15℃(after increasing ). Low temperature could cause decrease and thus cause distinct decreasing of COD removal efficiency. However, increasing could increase and accordingly increase COD removal efficiency.

To determine the operation parameters of the expanded granular sludge bed (EGSB) reactor treating actual domestic wastewater at ambient temperature of 15-26℃, the effects of influent flow, HRT, recycle ratio,Vup and temperature on the performance of the EGSB reactor were investigated in this paper. The results indicated that when treating actual domestic wastewater, the EGSB reactor could support high influent flow and low HRT. For 9L.h-1, 11L.h-1, 15L.h-1, 24L.h-1 influent flow, with the optimal recycle ratios of 1.6-2.5, 1.2-1.6, 0.4-0.8, 0.0, the COD removal efficiencies could attain to 86-90%, 88-89%, 83%, 83%, respectively. For lower influent flow, higher Vup could slightly increase COD removal, but accordingly higher recycle ratio need to supply. Meanwhile, for higher influent flow, higher Vup will damage the granular characteristic and thus cause the decreasing of COD removal, and thus for the EGSB reactor treating actual domestic wastewater, 2.7-3.0m.h-1 optimal Vup should be employed. The EGSB reactor could work well at ambient temperature of 15℃-26℃. The optimal influent flow and Vup were 15-24L.h-1 and 3.0m.h-1. High average OLR of 18.6kgCOD.m-3.d-1 and high average COD removal efficiencies of above 81.4% could achieve, and only very low recycle ratio of 0.0 to 0.4 need employ.

Abstract: A novel cDNA of phospholipid hydroperoxide glutathione peroxidase (PHGPx), which encodes a functional protein capable of complementing the yeast PHGHX-deletion mutant, was recently discovered in radish (Raphanus sativus) and designated as RsPHGPx [Yang X-D, Li W-J, Liu J-Y (2005) Biochim Biophys Acta 1728:199–205]. Sequence alignment suggested that RsPHGPx contains a targeting peptide required for transport to mitochondria, but the experimental evidence for the exact intracellular distribution of RsPHGPx remains to be elucidated. To uncover the cellular localization of plant PHGPx, we first investigated RsPHGPx’s intracellular distribution. Western blot analysis of subcellular fractions using the RsPHGPx antiserum clearly indicated the distribution of RsPHGPx in the radish mitochondrial fraction. Furthermore, a construct expressing the RsPHGPx precursor tagged with green fluorescent protein was introduced into tobacco and yeast cells, and the fusion protein was transported into both mitochondria, indicating that RsPHGPx was indeed localized in mitochondria. To explore the biochemical functions of this enzyme, we tested the enzymatic activity of the recombinant RsPHGPx protein. It displayed GSH-dependent peroxidase activity and exhibited the largest affinity to and the highest catalytic efficiency on phosphatidylcholine hydroperoxide, suggesting that phospholipid hydroperoxide is probably the optimum substrate for RsPHGPx. Furthermore, RsPHGPx showed a much higher V max value, by two orders of magnitude, than those of all other known plant PHGPxs. Taken together, these results showed evidence for the first time of mitochondrial localization and higher activity of PHGPx in plants and provided a framework for continued studies on the physiological functions of RsPHGPx.