Self-generated electric field to suppress sludge production and fouling development in a membrane bioreactor for wastewater treatment.

Compared with conventional sludge reduction techniques, electric field assisted membrane bioreactor (MBR) is a cost-effective technology with low power consumption. In this study, spontaneous electric field without extra power supply was introduced into the MBR for wastewater treatment to complete the in situ sludge reduction and membrane fouling mitigation. A novel spontaneous electric field membrane bioreactor (SEF-MBR) equipped with Cu-nanowires (Cu-NWs) conductive microfiltration membrane as cathode was established by using baffles to form anaerobic and aerobic tanks.

The growth process of the cake layer and membrane fouling alleviation mechanism in a MBR assisted with the self-generated electric field.

The electric field assisted membrane bioreactor (MBR) is an effective technique to alleviate membrane fouling. In this study, the spontaneous electric field was introduced into the MBR to observe the growth process of cake layer on the membrane surface. The external resistance for spontaneous electric field MBR (S-50) and S-500 were 50 Ω and 500 Ω respectively.

A spontaneous electric field membrane bioreactor with the innovative Cu-nanowires conductive microfiltration membrane for membrane fouling mitigation and pollutant removal.

In this study, a spontaneous electric field membrane bioreactor (SEF-MBR), equipped with the innovative Cu-nanowires conductive microfiltration membrane, was developed to achieve membrane fouling mitigation and high-quality effluent. The membrane fouling was significantly mitigated due to the presence of spontaneous electric field that the intensity of the spontaneous electric field in the established SEF-MBR was up to 0.073 V/cm.

Key cytomembrane ABC transporters of Saccharomyces cerevisiae fail to improve the tolerance to D-limonene.

ATP-binding cassette transporters (ABC) are important detoxification proteins and were proposed to play important roles in monoterpene resistance in Saccharomyces cerevisiae. In this work, the transcriptional levels of typical ABC transporters of S. cerevisiae under 85 mg D-limonene/l were evaluated using real-time quantitative PCR.

Optimization of fumaric acid production by Rhizopus delemar based on the morphology formation.

The effects of temperature, agitation rate and medium composition, including concentrations of glucose, soybean peptone, and inorganic ions, on pellet formation and pellet diameter of Rhizopus delemar (Rhizopus oryzae) NRRL1526 during pre-culture were studied. Inorganic ions and soybean peptone had negative and positive effects on pellet formation, respectively. The initial glucose and soybean peptone concentrations directly affected pellet diameter.

Improvement of alcoholic fermentation by calcium ions under enological conditions involves the increment of plasma membrane H(+)-ATPase activity.

The effect of Ca(2+) on alcoholic fermentation and plasma membrane H(+)-ATPase activity of wine yeast under enological conditions were investigated in this study. The results showed that fermentation rate, cell growth and ethanol production were improved by 0.5 and 1.

Improvement of laccase production and its properties by low-energy ion implantation.

Low-energy ion implantation was employed to breed laccase producing strain Paecilomyces sp. WSH-L07 and a mutant S152 that exhibited an activity of more than three times over the wild strain was obtained. The optimum substrate of both the wild and mutant laccases was 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate), and followed by guaiacol with optimal pH at 3.

Enhancement of cell viability and alkaline polygalacturonate lyase production by sorbitol co-feeding with methanol in Pichia pastoris fermentation.

Alkaline polygalacturonate lyase (PGL) production by Pichia pastoris GS115 was used as a model to study the mechanism and strategy for enhancing heterologous protein production. In order to enhance cell viability and volumetric recombinant protein productivity, sorbitol, which had been confirmed to be a non-repressive carbon source, was added together with methanol during the induction phase. The resultant PGL activity was up to 1593 U mL(-1), which was enhanced 1.

[Overproduction of catalase by oxidative stress on Bacillus subtilis WSHDZ-01].

We studied the overproduction of catalase (CAT) by Bacillus sp.WSHDZ-01 by oxidative stress via the feeding of ethanol and the pulse addition of H2O2. By adding 2.

A newly isolated Paecilomyces sp. WSH-L07 for laccase production: isolation, identification, and production enhancement by complex inducement.

Laccase can catalyze the oxidation of a wide range of organic and inorganic substrates. In this study, an easily detectable method was employed for screening laccase-producing microorganisms by using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) as laccase-secretion indicator. A novel laccase-producing strain was isolated and identified as Paecilomyces sp.

Enhancement of alkaline polygalacturonate lyase production in recombinant Pichia pastoris according to the ratio of methanol to cell concentration.

Polygalacturonate lyase (PGL) production by Pichia pastoris GS115 was used as a model to study the mechanism and strategy for enhancing heterologous protein production. It was found that the ratio of methanol to cell concentration had a significant influence on PGL production. In this study, an advanced glycerol exponential feeding strategy was developed for biomass accumulation in cell growth phase, by which cell concentration reached 140 g L(-1) after 19 h glycerol feeding.

[High-level production of alkaline polygalacturonate lyase in recombinant Pichia pastoris].

In order to increase the production of alkaline polygalacturonate lyase (PGL) by recombinant Pichia pastoris GS115, the effect of cell and methanol concentration on the PGL production was carefully investigated by single factor experiment. The optimum conditions were listed as follows: the cell concentration 122 g/L, the methanol concentration 20 g/L, and the ratio of methanol and cell concentration 0.16-0.

[Response of bacillus sp. F26 to different reactive oxygen species stress characterized by antioxidative enzymes synthesis].

The oxidative response of Bacillus sp F26 to different forms of reactive oxygen species (ROS) stress including H2O2, O2- * and OH * were investigated by using diverse generating source of ROS, which were characterized by synthesis of antioxidative enzymes. It was shown that the responses of cells to oxidative stress are largely dependent on species, mode (instantaneous and continual) and intensity of stress. Higher synthesis rate of catalase (CAT) is crucial for Bacillus sp F26 to resist H2O2 stress.

Scavenging of free radicals in gas-phase mainstream cigarette smoke by immobilized catalase at filter level.

Catalase is well known as capable of inducing the decomposition of H(2)O(2). In this study, a kind of immobilized catalase (entrapped in cross-linked chitosan beads) was dispersed in conventional acetate filter as an antioxidant additive. Quantitative estimation of the free radicals in mainstream cigarette smoke (MCS) was performed to address the effect of this modified filter.

A new photon kinetic-measurement based on the kinetics of electron-hole pairs in photodegradation of textile wastewater using the UV-H2O2FS-TiO2 process.

Actual textile wastewater and synthesized wastewater containing various textile dyes were photocatalytic degraded by the UV-H2O2FS-TiO2 process in an annular-flow photocatalytic reactor. In this process, a photon kinetic-measure was adopted to obtain constant rates of dyes decomposition. It was theorized that, by illumination at different UV frequencies, the electrons within the semiconductor were excited from the valence band to the conduction band, yielding the formation of electron-hole pairs which are the pre-requisites for photocatalysis.

Production of polyvinyl alcohol-degrading enzyme with Janthinobacterium sp. and its application in cotton fabric desizing.

A strain capable of using polyvinyl alcohol (PVA) as sole carbon source was isolated from soil samples of a textile factory. The 16S rDNA sequence analysis cell morphology, physiology and biochemistry showed that it belonged to Janthinobacterium sp. This is the first report to show that the screened Janthinobacterium sp.

Enhanced cutinase production with Thermobifida fusca by two-stage pH control strategy.

A mutant of Thermobifida fusca ATCC 27730 was used for cutinase production. Acetate was the most suitable carbon source for cell growth and cutinase production compared with others. The pH was one of the most important factors affecting cutinase yield and productivity.

Study and improvement of the conditions for production of a novel alkali stable catalase.

Catalase (CAT) is an enzyme capable of catalyzing the conversion of H(2)O(2) to O(2) and H(2)O. It has recently acquired interest due to its attractive potential application in the textile industries. In a previous study, a bacterium with slight halophilic and alkaliphilic characteristics, Bacillus sp.

Order of photocatalytic degradation as ranked by critical photonic times (CPTs) indicates the composition of organic dye mixtures: selectivity of hydroxyl radicals.

A simple critical photonic time (CPT) ranking method for the simultaneous determination of known organic dyes in the industrial wastewater of different concentrations was developed. A kinetic-measure, CPT theory, was developed to discriminate between the dyes in the textile effluent solution. The CPTs were calculated and ranked 1-4 from the smallest to the largest.

Simultaneous nitrification and denitrification in an aerobic reactor with granular sludge originating from an upflow anaerobic sludge bed reactor.

Anaerobic granular sludge, obtained from an upflow anaerobic sludge bed reactor at a brewery waste treatment station, was cultured for 3 months under aeration conditions until the diameter of sludge was in the range 1.8 to 2.6 mm.

Biodegradation of petroleum hydrocarbons by two Pseudomonas aeruginosa strains with different uptake modes.

The uptake modes of alkanes by two strains (Pseudomonas aeruginosa S and Pseudomonas aeruginosa Y) were compared in this article. It was found that the strain of P. aeruginosa S showed low cell surface hydrophobicity and the surface tension of the broth decreased when the strain was cultivated on alkanes.

Adaptive response of Bacillus sp. F26 to hydrogen peroxide and menadione.

The adaptive and cross-protection responses to oxidants were investigated in Bacillus sp. F26. The cells were treated with sublethal concentrations of either H(2)O(2) or menadione (a superoxide-generating agent) to induce an adaptive response.

Enhanced catalase synthesis by a novel combined system of photocatalytic reactor and fermentor.

A novel combined system of a photocatalytic reactor, with UV and titanium dioxide as photocatalyst, and a fermentor with Bacillus sp. F26 as catalase producer was developed. Production of catalase was enhanced by 14% to 18.

Influence of biosurfactants produced by Candida antarctica on surface properties of microorganism and biodegradation of n-alkanes.

The objective of this study was to investigate the influence of the biosurfactant BS-UC on surface properties of microbial cells and biodegradation of petroleum hydrocarbons. The biosurfactant BS-UC was produced by Candida antarctica from n-undecane as the substrate. It was found that the addition of BS-UC influenced positively the emulsification and the biodegradation of a variety of n-alkanes substrates.