Commercial formulation amendment transiently affects the microbial composition but not the biogas production of a full scale methanogenic UASB reactor.

The treatment of dairy wastewater in methanogenic reactors cause several problems due to their high lipid content. One strategy to overcome these problems is the use of commercial formulations. Here we studied the effect of adding a commercial formulation, designed to improve fat degradation, on both the microbial community composition and reactor performance. Samples from two full-scale Up-flow Anaerobic Sludge Blanket (UASB) reactors in parallel arrangement were analysed. The commercial product was added to one of the reactors while the other was used as control. The amendment increased significantly the fat removal but an accumulation of volatile fatty acids was detected. Nevertheless, no significant differences were observed in the total Chemical Oxygen Demand (COD) removal and biogas production between reactors. A significant change in the bacterial community was not detected by 16S rRNA gene Terminal Restriction Fragment Length Polymorphism (T-RFLP) analysis probably due to the limitation of the technique. A strong change in the composition of the phylum Firmicutes was detected with 16S rRNA gene amplicon sequencing; however, it didn't persist during the whole operation period. The relative abundance of minor Operational Taxonomic Units (OTUs) with sequences related to syntrophic bacteria increased with the amendment. Although a better hydrolytic capacity was obtained when adding the commercial product, the overall process did not improve and no increase in biogas production was detected. Alternative strategies could be applied to avoid the accumulation of intermediary products and improve biogas production as intermittent addition of the commercial product or batch operation of reactors.

Preliminary analysis of Chloroflexi populations in full-scale UASB methanogenic reactors.

AIMS: The phylum Chloroflexi is frequently found in high abundance in methanogenic reactors, but their role is still unclear as most of them remain uncultured and understudied. Hence, a detailed analysis was performed in samples from five up-flow anaerobic sludge blanket (UASB) full-scale reactors fed different industrial wastewaters. METHODS AND RESULTS: Quantitative PCR show that the phylum Chloroflexi was abundant in all UASB methanogenic reactors, with higher abundance in the reactors operated for a long period of time, which presented granular biomass. Both terminal restriction fragment length polymorphism and 16S rRNA gene amplicon sequencing revealed diverse Chloroflexi populations apparently determined by the different inocula. According to the phylogenetic analysis, the sequences from the dominant Chloroflexi were positioned in branches where no sequences of the cultured representative strains were placed. Fluorescent in situ hybridization analysis performed in two of the reactors showed filamentous morphology of the hybridizing cells. CONCLUSIONS: While members of the Anaerolineae class within phylum Chloroflexi were predominant, their diversity is still poorly described in anaerobic reactors. Due to their filamentous morphology, Chloroflexi may have a key role in the granulation in methanogenic UASB reactors. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results bring new insights about the diversity, stability, dynamics and abundance of this phylum in full-scale UASB reactors which aid in understanding their function within the reactor biomass. However, new methodological approaches and analysis of bulking biomass are needed to completely unravel their role in these reactors. Combining all this knowledge with reactor operational parameters will allow to understand their participation in granulation and bulking episodes and design strategies to prevent Chloroflexi overgrowth.

Antineutrophil cytoplasmic antibodies in inflammatory bowel disease: clinical role and review of the literature.

PURPOSE: Perinuclear antineutrophil cytoplasmic antibodies have been found consistently in patients with ulcerative colitis; however, their pathogenetic and clinical role is still uncertain. In this study we tested the prevalence of perinuclear antineutrophil cytoplasmic antibodies in a large population of patients with ulcerative colitis and Crohn's disease, with particular attention to the possible correlation with clinical features. METHODS: Perinuclear antineutrophil cytoplasmic antibody reactivity was investigated with indirect immunofluorescence in 279 patients with ulcerative colitis, 110 patients with Crohn's disease, and 252 unrelated healthy subjects. RESULTS: Perinuclear antineutrophil cytoplasmic antibodies were found in 84 of 279 patients with ulcerative colitis (30 percent), 10 of 110 patients with Crohn's disease (9 percent), and 2 of 252 healthy subjects (<1 percent; P < 0.001), respectively. Perinuclear antineutrophil cytoplasmic antibodies were significantly more frequent in patients with ulcerative colitis with higher relapse rate (43 vs. 27 percent; P < 0.002), and patients with Crohn's disease with colitis (27 vs. 2.5 percent; P < 0.0003). Perinuclear antineutrophil cytoplasmic antibodies were also significantly less frequent in patients with ulcerative colitis in remission (18 vs. 34 percent; P < 0.0025). CONCLUSIONS: In this study we confirm the relative specificity of perinuclear antineutrophil cytoplasmic antibodies, either for ulcerative colitis or for Crohn's disease involving the colon. Perinuclear antineutrophil cytoplasmic antibodies were more frequently found in patients with ulcerative colitis with a more aggressive clinical behavior; however, their presence had a limited value in identifying homogeneous subgroups of patients in our population.

Genetic analysis in Italian families with inflammatory bowel disease supports linkage to the IBD1 locus--a GISC study.

Epidemiological studies suggest that inherited factors influence susceptibility to inflammatory bowel disease (IBD), and some candidate loci have been described. In order to verify whether the same loci are responsible for predisposition to IBD in our population, we carried out a linkage study in a series of 58 Italian families with Crohn's disease (CD) and ulcerative colitis (UC). HLA-DQ alleles, motilin gene, and 34 microsatellites flanking the previously described loci on chromosomes 3, 6, 7, 12 and 16 were analysed by non-parametric linkage analysis in 16 and 23 families with CD and UC, respectively, and in 19 families where CD and UC coexisted. Non parametric analysis using GENEHUNTER yielded maximum NPL scores for marker D16S408 in all IBD families combined (2.71, P = 0.003), for marker D16S419 in CD (1.97, P = 0.026) and for marker D16S514 in UC families (2.44, P = 0.007). These markers map in the previously described IBD1 region. No significant linkage was found for markers of chromosomes 3, 6, 7 and 12. The present study performed in a Southern European population provides additional support for the conclusion with the IBD1 locus has a clear role in the genetic susceptibility to IBD.