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关键词： Cow manure   Anaerobic digestion   Volatile fatty acids   Membrane bioreactor  

摘要： Cow manure (CM) generation in large volumes has for long been considered a waste management challenge. However, the organic content of CM signals opportunities for the production of value-added bioproducts such as volatile fatty acids (VFAs) through anaerobic digestion (AD). However, a robust VFAs fermentation process requires effective methane formation inhibition and enhance VFAs recovery. In this study, thermal pretreatment was applied to inhibit methanogens for enhanced VFAs production and an immersed membrane bioreactor (iMBR) for in situ recovery of VFAs in a semi-continuous AD. Maximal VFAs yield of 0.41 g VFAs/g volatile solids (VS) was obtained from thermally-treated CM without inoculum addition. The CM was further fed to the iMBR operating at organic loading rates of 0.8-4.7 gVS/L.d. The VFAs concentration increased to 6.93 g/L by rising substrate loading to 4.7 g VS/L.d. The applied iMBR set-up was successfully used for stable long-term (114 days) VFAs production and recovery.

关键词： Reactive blue 40   Response surface methodology   Mixture design   FTIR   UV-visible  

摘要： The textile dyeing and printing industries has led to extensive environmental pollution and severely threatens ecosystems. The best microbial species for such application was selected among the isolated bacterial populations by conducting CI Reactive Blue 40 (CI RB 40) batch degradation studies with the bacterial-algal-probiotic strains. In this study, three suitable species (Pseudomonas putida, Chlorella and Lactobacillus plantarum) were applied to degrade and detoxify CI RB 40, a reactive diazo dye in Real Textile Wastewater, used in textile dyeing industry worldwide. Process parameters were optimized using Response Surface Methodology and under the optimum conditions (e.g., inoculum size of 10%), temperature of 35 150 ppm, and time of 6 days). The maximum COD and color removal efficiencies, when tested with 1000 ppm of dye using batch reactors were found to be 89% and 99%, respectively. Our results showed also that bacteria had a high decolorization capacity. The regression analysis revealed a good match of the experimental data to the second-order polynomial with a high coefficient of determination (R2). UV-Visible and FTIR spectroscopy analysis confirmed the biodegradation of CI RB 40. Finally, toxicity of CIRB 40 before and after biodegradation was studied and the detoxification of CIRB 40 dye solution after biodegradation process was confirmed.

关键词： Denitrification   Micro-electrolysis   Nitrate removal   PPC@FeC bioreactor  

摘要： In the current research, a novel bioreactor composed of porous polymer carriers and iron-carbon (PPC@FeC) was established through bacterial immobilized technology. The influence of key factors was studied on the nitrate removal performance of the PPC@FeC bioreactor. The experimental results showed that the highest removal rate of nitrate (7.33 mg L-1 h(-1)) can be obtained with short hydraulic retention times (HRT = 2.0 h) and low carbon-to-nitrogen ratio (C/N = 2.0). The results of high-throughput sequencing revealed that Zoogloea sp. L2 was the dominant strain in bioreactor responsible for nitrate removal. Moreover, the SEM and XRD analyses elucidated that Fe2O3 was the final product produced by the interaction of FeC and strain L2. These findings showed that the PPC@FeC bioreactor successfully combined micro-electrolysis and biological denitrification, which exhibited great potential in removing nitrate effectively from wastewater under low C/N ratio and short HRT conditions.

关键词： Azo dye   Bacteria immobilization   Degradation metabolites   Shewanella indica strain   Textile wastewater treatment  

摘要： Decolorization and removal of contaminants in textile wastewater are essential for pollution control. This study investigated the potential application of a halophilic and halotolerant Shewanella indica (S. indica) strain as immobilized biofilm in two attached growth bioreactors with moving bed bioreactor carrier and polyurethane porous gel carrier, respectively. Under optimized operation conditions, both bioreactors had high tolerance for Reactive Black 5 (RB5) concentration fluctuation and could decolorize RB5 effectively and stably (97% on average) for over 6 months. The decolorization of RB5 in bioreactors was mainly due to microbially mediated cleavage of the azo dye, though adsorption by biofilm and carrier (contribution of different carriers varied) also contributed to the process. However, the azo dye was barely mineralized, and the toxicity remained after decolorization. Overall, this study demonstrated the viability and sustainability of the bioreactors incubated with S. indica in decolorizing RB5. Nevertheless, further technologies need to be explored to detoxify the degradation metabolites.

关键词： Aged refuse   Chemical oxygen demand and color removal   Filled bioreactor   Material from landfill   Sugar industry wastewater  

摘要： The serious pollution problem that exists nowadays in aquatic environments has been caused, mainly, by intensive industrial activity. For this reason, this article presents the results obtained in the treatability tests of sugar mill wastewater, using an aged refuse filled bioreactor, (o = 0.2 m,h = 3.0 m, of PVC), which was fed under four hydraulic loads (50, 100, 150 and 200 L/m(3) day), each of them for a period of 8 weeks. The efficiency of the system was evaluated by the removal of the chemical oxygen demand (COD) and color. The average values in the influent were 2473 +/- 437 mg/L for COD and 1048 +/- 287 Pt-Co for color. The highest COD removal (98.8%) was achieved with a hydraulic load of 100 L/m(3) day, generating an effluent with an average value of 26.8 mg COD/L. In the case of color, a removal of 84.2% was achieved. The results obtained show the evaluated system as an efficient, novel and friendly alternative in its operation, with minimum sludge and odors generation in the treatment of wastewater generated in the cane sugar extraction process.

关键词： Low rank coal   Bioreactor   DBT   BDS   Rhodococcus sp   ATCC55309  

摘要： Combustion of coal create many harmful gases which effect on human health as well as on environment. The sulfur in coal limits its own use, and bio-desulfurization (BDS) shows enormous development potential and the prospects for the application of coal desulfurization. Present study highlights the bioprocess strategies for reduction of sulfur content from coal before combustion. The bioprocess involved the use of Airlift Bioreactor along withRhodococcus sp. ATCC55309 as biocatalyst. Different nutritional and operational parameters involved to promote sulfur reduction at maximum level. The parameters were investigated are different carbon source, temperature, pH, Agitation speed, and pulp density. The impact of these parameters shows that sulfur removal can be enhanced though optimized conditions. The amount of total sulfur and organic sulfur present in coal were reduced by 33 +/- 1.7% and 71 +/- 1.5%, respectively, compared to untreated coal at controlled condition of various parameters are 20% (w/v) pulp density, 30 degrees C, 170 rpm, glucose as carbon source and pH 7. Whereas organic sulfur degrades from coal usingRhodococcus sp. ATCC55309 about 0.36 mM DBT (Di-benzothiophene) within 8 days via 4S-pathway. The maximum conversion of DBT compound into 2-HBP(2-hydroxybiphenyl) by utilizing 30 degrees C, 170 rpm, 20 pulp density and glucose as carbon source.

关键词： Biodiesel waste   Energy recovery   Industrial landfill   Methane yield  

摘要： Anaerobic co-digestion from industrial waste landfill (IWL) leachate and glycerin was evaluated in a continuous anaerobic bioreactor with fixed-structured bed (ABFSB) under mesophilic conditions (30 +/- 1 degrees C). The ABFSB reactor had a useful volume of 4.77 L. The support medium consisted of polyurethane (PU) foam arranged in an orderly manner. The substrate used corresponded to a mixture of 95% IWL leachate and 5% glycerin (v/v) and the inoculum consisted of flocculent anaerobic sludge. The ABFSB reactor was operated in two phases the 1st phase (between the 49th and the 439th days of operation): started after the inoculum adaptation and the effect of the increase in the organic loading rate (OLR) was evaluated (2;3.5;7.1 and 11.6 gCOD L-1 d(-1));the 2nd phase (between the 440th and 471st days of operation): the effect of the reduction in alkalinity supplementation via sodium bicarbonate (NaHCO3) was evaluated (0.56;0.42;0.28;0.14 gNaHCO(3) gCOD(influent)(-1) and non-supplementation). The OLR of 7.1 gCOD L-1 d(-1) was the condition that presented the best results in the 1st phase for the parameters: maximum methane flow rate (MFR) (7.61 LNCH4 d(-1)), methane yield (MY) (0.30 LNCH4 gCOD(removed)(-1) ), volumetric methane production rate (VMPR) (2.79 LNCH4 L-1 d(-1)), COD removal efficiencies (ERTCOD) and soluble COD (ERSCOD) higher than 90%. In the 2nd phase, the reactor was operated with an OLR of 7.1 gCOD L-1 d(-1) and a hydraulic retention time (HRT) of 35.22 h and CODinfluent of 10.68 g L-1. The minimum alkalinity supplementation required was 0.28 gNaHCO(3)gCOD(influent)(-1), a condition in which the reactor showed stability and satisfactory performance for the parameters: MFR (9.48 LNCH4 d(-1)), MY (0.33 LNCH4 gCOD(removed)(-1) ) and VMPR (3.18 LNCH4 L-1 d(-1)). It was concluded that the ABFSB reactor proved to be stable in the IWL leachate co-digestion and glycerin, when the alkalinity supplementation, effectively necessary, was met. (c) 2020 Elsevier Ltd.

关键词： Adventitious root   Bioactive compounds   Bioreactor culture   FT-IR   Root biomass  

摘要： Key message The optimum condition for bioreactor culture of Polygonum multiflorum is full-strength MS medium supplemented with 2 mg center dot L-1 IBA and 5% sucrose after 4 weeks of culture. FT-IR analysis can rapidly discriminate among root samples based on total metabolite equivalence. Bioreactor cultures have been used for biomass production and bioactive compounds accumulation in adventitious root cultures of medicinal plants. In this study, we evaluated the effects of different auxin types [indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA)] and concentrations (0.5, 1.0, 2.0 and 4.0 mg center dot L-1), Murashige and Skoog (MS) medium salt strength (0.25, 0.5, 0.75, 1.0, 1.5 and 2X), and sucrose concentrations (0, 1.5, 3, 5, 7 and 10%) on Polygonum multiflorum Thunb. adventitious root cultures in a 3-L balloon-type bubble bioreactor (BTBB). IBA (1, 2, and 4 mg center dot L-1) was more effective than NAA in promoting root growth. Additionally, low MS salt strength (0.25 and 0.5X MS) increased the accumulation of total phenolics and flavonoids but reduced biomass accumulation. Four weeks of culture in full-strength MS medium supplemented with 2 mg center dot L-1 IBA and 5% sucrose resulted in the highest root biomass [98.46 g center dot L-1 fresh weight (FW);13.46 g center dot L-1 dry weight (DW)] and bioactive compounds accumulation (total phenolics compounds, 53.08 mg center dot g(-1) DW;total flavonoids, 25.10 mg center dot g(-1) DW). To determine whether metabolic fingerprinting of whole-cell extracts could be used to compare metabolic equivalence of P. multiflorum root samples, we treated adventitious roots with different culture conditions, and analyzed the treated adventitious roots and natural roots by Fourier transform infrared (FT-IR) spectroscopy. The results showed that the metabolic pattern of adventitious root samples was similar under different culture conditions;however, these samples could be discriminated from each other in pilot-sca

关键词： Ureaplasma   Ureaplasma parvum   Growth   Culture   Bioreactor  

摘要： Ureaplasma species, including Ureaplasma parvum and Ureaplasma urealyticum, are challenging to culture and maintain. Here, we describe a novel bioreactor for growing high-titer liquid Ureaplasma cultures in a stable manner.

关键词： Pichia pastoris   Heterologous protein production   Signal sequence   Translocation   Secretion   Alpha-factor  

摘要： Pichia pastoris (Komagataella spp.) has become one of the most important host organisms for production of heterologous proteins of biotechnological interest, many of them extracellular. The protein secretion pathway has been recognized as a limiting process in which many roadblocks have been pinpointed. Recently, we have identified a bottleneck at the ER translocation level. In earlier exploratory studies, this limitation could be largely overcome by using an improved chimeric secretion signal to drive proteins through the co-translational trans location pathway. Here, we have further tested at bioreactor scale the improved secretion signal consisting of the pre-Ost1 signal sequence, which drives proteins through co-translational translocation, followed by the pro region from the secretion signal of the Saccharomyces cerevisiae alpha-factor mating pheromone. For comparison, the commonly used full-length alpha-factor secretion signal, which drives proteins through post-translational trans location, was tested. These two secretion signals were fused to three different model proteins: the tetrameric red fluorescent protein E2-Crimson, which can be used to visualize roadblocks in the secretory pathway;the lipase 2 from Bacillus thermocatenulatus (BTL2);and the Rhizopus oryzae lipase (ROL). All strains were tested in batch cultivation to study the different growth parameters obtained. The strains carrying the improved secretion signal showed increased final production of the proteins of interest. Interestingly, they were able to grow at significantly higher maximum specific growth rates than their counterparts carrying the conventional secretion signal. These results were corroborated in a 5 L fed-batch cultivation, where the final product concentration and volumetric productivity were also shown to be improved.