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Highlights: [•] New concept for ammonium recovery from reject water. [•] Ammonium recovery could be combined with hydrogen production. [•] 57–79% of the total nitrogen in real reject water was recovered. [Copyright &y& Elsevier]

Abstract: In this study, a systemic analysis was initially performed to investigate the relationship between fermentation-related stress tolerances and ethanol yield. Based on the results obtained, two elite Saccharomyces cerevisiae strains, Z8 and Z15, with variant phenotypes were chosen to construct strains with improved multi-stress tolerance by genome shuffling in combination with optimized initial selection. After three rounds of genome shuffling, a shuffled strain, YZ1, which surpasses its parent strains in osmotic, heat, and acid tolerances, was obtained. Ethanol yields of YZ1 were 3.11%, 10.31%, and 10.55% higher than those of its parent strains under regular, increased heat, and high gravity fermentation conditions, respectively. YZ1 was applied to bioethanol production at an industrial scale. Results demonstrated that the variant phenotypes from available yeast strains could be used as parent stock for yeast breeding and that the genome shuffling approach is sufficiently powerful in combining suitable phenotypes in a single strain. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new strain of aerobic bacterium, Bacillus cereus JP12, could effectively degrade BDE-209. [•] The first report on the degradation of BDE-209 by Bacillus cereus. [•] A slight stimulating effect on BDE-209 removal under low levels of Cu2+ and Zn2+. [•] JP12 could effectively degrade BDE-209 under high concentrations of Cu2+ and Zn2+. [•] Metabolite identification and deduction of a possible BDE-209 degradation pathway. [ABSTRACT FROM AUTHOR]

In this study, the feasibility of application of anaerobic ammonium oxidation (anammox) to teat wastewater containing chromium was assessed. Anammox granule activity decreased with increasing Cr(VI) concentration and pre-exposure time in batch tests, and the 50% inhibition concentration of Cr(VI) on anammox biomass was 296.5 mg L −1 . Approximately 93.9% chromium was absorbed by loosely bound-extracellular polymeric substances and tightly bound-extracellular polymeric substances when less than 60 mg L −1 Cr(VI) was added. During long-term operation in up-flow anaerobic sludge blanket reactor, significant inhibitory effects anammox performance were observed for Cr(VI) concentrations up to 2 mg L −1 . The nitrogen removal rate (NRR) rapidly decreased to 1.49 ± 0.89 kg N m −3  d −1 , whereas the NRR was 11.37 ± 1.30 kg N m −3  d −1 in a control reactor. Compared with initial levels, specific anammox granule activity was 22%. The tolerance of the anammox process to Cr(VI) can be enhanced after a long-term adaptive phase. [ABSTRACT FROM AUTHOR]

The aim of this work was to develop a novel strategy for improving the vanillin tolerance and ethanol fermentation performances of Saccharomyces cerevisiae strains. Isogeneic diploid, triploid, and tetraploid S. cerevisiae strains were generated by genome duplication of haploid strain CEN.PK2-1C. Ploidy increments improved vanillin tolerance and diminished proliferation capability. Antimitotic drug methyl benzimidazol-2-ylcarbamate (MBC) was used to introduce chromosomal aberrations into the tetraploid S. cerevisiae strain. Interestingly, aneuploid mutants with DNA contents between triploid and tetraploid were more resistant to vanillin and showed faster ethanol fermentation rates than all euploid strains. The physiological characteristics of these mutants suggest that higher bioconversion capacities of vanillin and ergosterol contents might contribute to improved vanillin tolerance. This study demonstrates that genome duplication and MBC treatment is a powerful strategy to improve the vanillin tolerance of yeast strains. [ABSTRACT FROM AUTHOR]

Highlights: [•] Industrial yeast strains were engineered for more intercellular trehalose content. [•] The protective effect of trehalose depends on its content and the level of stress. [•] Trehalose accumulation is more important for VHG fermentation than regular one. [•] It had great potential for improving VHG performances of industrial yeast strains. [ABSTRACT FROM AUTHOR]

Abstract: The optimization, purification and characterization of bioflocculant produced by Paenibacillus elgii B69 were investigated. The bioflocculant was an exopolysaccharide composed of glucose, glucuronic acid, mannose and xylose. The maximum bioflocculant production was about 25.63g/L achieved with sucrose at 51.35g/L, peptone at 6.78g/L and yeast extract at 0.47g/L optimized by response-surface methodology. In addition, a series of experiments was performed to investigate the flocculation activities towards kaolin clay, dyeing pigment, heavy metal ion, and real wastewater and the result indicated the new bioflocculant had high activities towards all the tested pollutions. These results showed its great potential for water pretreatment used in industry. [Copyright &y& Elsevier]

Abstract: A challenge associated with the ethanol productivity under very-high-gravity (VHG) conditions, optimizing multi-traits (i.e. byproduct formation and stress tolerance) of industrial yeast strains, is overcome by a combination of metabolic engineering and genome shuffling. First, industrial strain Y12 was deleted with a glycerol exporter Fps1p and hetero-expressed with glyceraldehydes-3-phosphate dehydrogenase, resulting in the modified strain YFG12 with lower glycerol yield. Second, YFG12 was subjected to three rounds of drug resistance marker-aided genome shuffling to increase its ethanol tolerance, and the best shuffled strain TS5 was obtained. Compared with wild strain Y12, shuffled strain TS5 not only decreased glycerol formation by 14.8%, but also increased fermentation rate and ethanol yield by 3.7% and 7.6%, respectively. Moreover, the system of genetic modification and Cre/loxP in aid of three different drug-resistance markers presented in the study significantly improved breeding efficiency and will facilitate the application of breeding technologies in prototrophic industrial microorganisms. [Copyright &y& Elsevier]

Abstract: The contributions of loosely bound extracellular polymeric substances (LB–EPS), tightly bound EPS (TB–EPS), residual sludge (the sludge left after EPS extraction) and functional groups such as amine, carboxyl, phosphate and lipid on aerobic granules on biosorption of four different dyes (Reactive Brilliant Blue KN–R (KN–R), Congo Red (CR), Reactive Brilliant Red K–2G (RBR) and Malachite Green (MG)) were investigated. EPS may be responsible for biosorption of cationic dyes. However, residual sludge always made greater contribution than that of EPS. The biosorption mechanisms were dependent on the functional groups on aerobic granules and dyes’ chemical structures. The lipid and phosphate groups might be the main binding sites for KN–R biosorption. Amine, carboxyl, phosphate and lipid were all responsible for the binding of CR. The lipid fractions played an important role for RBR biosorption. For MG, the phosphate groups gave the largest contribution. [ABSTRACT FROM AUTHOR]