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The diversity of ammonia-oxidizing bacteria (AOB) within the beta-subclass of Proteobacteria was investigated by genus- and family-specific real-time quantitative PCR (qPCR) assays on samples drawn from wastewater treatment systems. The 16S rRNA gene copy numbers ranged from 7.0 × 103 to 6.8 × 106, 1.1 × 107 to 1.8 × 107, and 2.9 × 105 to 1.5 × 107 copies/mL, respectively. Volumetric ammonium load (VAL) in the wastewater treatment systems calculated using the AOB numbers was in the range of 2.1-12.6 mM/d. Distribution patterns of eutrophic (i.e. Nitrosomonas europaea and Nitrosomonas nitrosa clusters) and oligotrophic (i.e. Nitrosomonas cryotolerans cluster) AOB groups were correlated with the VAL values. A high possibility of potential false-positive detection by family-specific qPCR assays was established by evaluating theoretical specificity in in silico and experimental investigations. The specificities of genusspecific qPCR assays were confirmed by amoA PCR, followed by cloning and sequencing. VAL must be the factor influencing the inclusion of AOB species. However, there was no significant correlation between the volatile suspended solid concentration representing chemical oxygen demand and N. europaea's community population, indicating that the degree of ammonia oxidation influenced the community cluster of Nitrosomonas relatively more. [ABSTRACT FROM AUTHOR]

A fermentative hydrogen-producing bacterium, Clostridium tyrobutyricum JM1, was isolated from a food waste treating process using 16S rRNA gene sequencing and amplified ribosomal DNA restriction analysis (ARDRA). A fixed-bed bioreactor packed with polyurethane foam as support matrix for the growth of the isolate was operated at different hydraulic retention time (HRT) to evaluate its performance for hydrogen production. The reactor achieved the maximal hydrogen production rate of 7.2l H2 l−1 d−1 at 2h HRT, where hydrogen content in biogas was 50.0%, and substrate conversion efficiency was 97.4%. The maximum hydrogen yield was 223ml (g-hexose)−1 with an influent glucose concentration of 5gl−1. Therefore, the immobilized reactor using C. tyrobutyricum JM1 was an effective and stable system for continuous hydrogen production. [Copyright &y& Elsevier]

Objectives: Since late preterm neonates are physiologically less mature than term neonates, the use of antenatal corticosteroids in the late preterm period has been recommended. The use of tocolytics can also be considered to gain valuable time for using antenatal corticosteroids in the late preterm period. In this study, we examined the efficacy of tocolytics on prolonging pregnancy in the late preterm period, by comparing women who received tocolytics with those who received none., Study Design: This retrospective cohort study included women who were admitted due to preterm labor after 34 weeks of gestation and delivered in the late preterm period. Primary outcome was time from admission to delivery (days). Secondary outcomes were the proportion of preterm births within 2 days, and within 7 days, completed cycles of antenatal corticosteroids, and the neonatal outcomes. Primary and secondary outcomes were compared according to the use of tocolytics. Propensity score matching was performed to create comparable groups. The maternal age, pre-pregnancy body mass index, nulliparity, history of preterm birth, hypertensive disease during pregnancy, gestational diabetes mellitus, history of preterm labor, gestational age at admission, cervical length, and the number of contractions were the baseline characteristics included in the propensity score., Results: Of 275 women, 44 women received tocolytics (tocolytics group) and 231 women did not (no tocolytics group). We matched 44 women who received tocolytics and 44 women who didn't. The tocolytics group was shown to exhibit a longer time from admission to delivery than the no tocolytics group, with a hazard ratio for tocolytics of 0.4 (95 % confidence interval, 0.2-0.6). In addition, the proportion of preterm births occurring within 2 days and 7 days were lower in those receiving tocolytics compared to those that didn't., Conclusion: In this propensity score matched-study, the use of tocolytics had a significant effect on pregnancy prolongation, which allows more time for use of corticosteroids in women with preterm labor after 34 weeks of gestation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The carbon metabolism of newly isolated Clostridium tyrobutyricum JM1 was investigated at varying initial glucose concentrations (27.8-333.6mM). Because an understanding of metabolic regulations was required to provide guidance for further effective metabolic design or optimization, in this case, maximizing hydrogen production, carbon material, and energy balances by C. tyrobutyricum JM1 were determined and applied in anaerobic glucose metabolism. The overall carbon distribution suggested that initial glucose concentrations had strong influence on the stoichiometric coefficients of products and the molar production of ATP on the formation of biomass. C. tyrobutyricum JM1 had a high capacity for hydrogen production at the initial glucose concentration of 222.4 mM with high concentrations of acetate and butyrate.

When synthetic wastewater containing Cr(VI) was placed in contact with the dead fungal biomass of Aspergillus niger, the Cr(VI) was completely removed from aqueous solution, whereas Cr(III), which was not initially present, appeared in aqueous solution. Desorption and X-ray photoelectron spectroscopy (XPS) studies showed that most of the Cr bound on the biomass was in trivalent form. These results indicated that the main mechanism of Cr(VI) removal was a redox reaction between Cr(VI) and the dead fungal biomass, which is quite different from previously reported mechanisms. The influences of contact time, pH, Cr(VI) concentration, biomass concentration and temperature on Cr(VI) removal were also evaluated. The Cr(VI) removal rate increased with a decrease in pH and with increases in Cr(VI) concentration, biomass concentration and temperature. Although removal kinetics was dependent on the experimental conditions, Cr(VI) was completely removed in the aqueous solution. In conclusion, a new mechanism of Cr(VI) removal by the dead fungal biomass has been proposed. From a practical viewpoint, this abundant and inexpensive dead fungal biomass has potential application in the conversion of toxic Cr(VI) into less toxic or nontoxic Cr(III).