136 research outputs found

    Complete autotrophic process for nitrogen removal from inkjet printing wastewater

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    Lab-scale results on the treatability of ammonium-rich wastewater from textile digital printing highlight the feasibility of an innovative biological process, based on purely autotrophic bacterial populations: ammonium oxidising bacteria (AOB) and anaerobic ammonium oxidisers (AAO). Activity of AOB has been measured through pH/DO-stat titration and that of AAO has been assessed through manometric tests, on raw mixed wastewater coming from textile-print factories (0.5 to 0-6 gN/L as ammonium nitrogen). AOB activity showed a reduction of 20-40% if compared with maximum activity on a synthetic medium. AAO activity tests showed a residual specific maximum anammox activity (SAA) of 0.1-0.4 gN2-N/gVSS/d, 40-60% of the control values obtained with synthetic wastewater. Activity tests confirmed treatability of the textile wastewater by AAO. Tests have been performed also on concentrated wastewater (2 to 3 gN/L as ammonium nitrogen) from the first rinsing bath. In this case, strong inhibition (between 80 and 100%) of anammox activity was observed. Careful operation of a continuous-flow completely mixed bioreactor can overcome this drawback, as pH and effluent ammonium concentration in the reactor are controlled

    Genetic mapping and identification of QTL for earliness in the globe artichoke / cultivated cardoon complex.

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    BACKGROUND: The Asteraceae species Cynara cardunculus (2n = 2x = 34) includes the two fully cross-compatible domesticated taxa globe artichoke (var. scolymus L.) and cultivated cardoon (var. altilis DC). As both are out-pollinators and suffer from marked inbreeding depression, linkage analysis has focussed on the use of a two way pseudo-test cross approach. RESULTS: A set of 172 microsatellite (SSR) loci derived from expressed sequence tag DNA sequence were integrated into the reference C. cardunculus genetic maps, based on segregation among the F(1) progeny of a cross between a globe artichoke and a cultivated cardoon. The resulting maps each detected 17 major linkage groups, corresponding to the species’ haploid chromosome number. A consensus map based on 66 co-dominant shared loci (64 SSRs and two SNPs) assembled 694 loci, with a mean inter-marker spacing of 2.5 cM. When the maps were used to elucidate the pattern of inheritance of head production earliness, a key commercial trait, seven regions were shown to harbour relevant quantitative trait loci (QTL). Together, these QTL accounted for up to 74% of the overall phenotypic variance. CONCLUSION: The newly developed consensus as well as the parental genetic maps can accelerate the process of tagging and eventually isolating the genes underlying earliness in both the domesticated C. cardunculus forms. The largest single effect mapped to the same linkage group in each parental maps, and explained about one half of the phenotypic variance, thus representing a good candidate for marker assisted selection
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