Comparison of various carbohydrates for hydrogen production in microbial electrolysis cells

The direct production of hydrogen from various carbohydrates of lignocellulosic biomass is examined by using single-chamber membrane-free microbial electrolysis cells. The mixed microbial culture was enriched with 20 mmol L−1 2-chloroethane sulphonate and 10 mmol L−1 sodium acetate as a carbon source. Hydrogen was produced from all carbon sources used, including monosaccharides (glucose, galactose, mannose, xylose and arabinose) and disaccharides (maltose, saccharose and cellobiose). Hydrogen gas (18 mL) was produced using 3.33 mmol L−1 maltose and 20 mL of hydrogen was produced using cellobiose after 14 d of operation. Methane was not produced under any of the tested conditions. The effects of sugar concentration were also examined. Hydrogen production rates varied from 0.01 m3 d−1 m−3 to 0.09 m3 d−1 m−3. The maximum hydrogen yield ranged from 14% to 111%. Our results suggested that carbohydrates, such as maltose and cellobiose, are suitable carbon sources for hydrogen production, when methanogens are suppressed

Combination of selenium and three naturally occurring antioxidants administration protects D-galactosamine-induced liver injury in rats

D-Galactosamine (D-GaIN) is a highly selective hepatotoxin that causes liver injury similar to human viral hepatitis via depletion of uridine nucleotides, which subsequently diminishes synthesis of RNA and proteins. The aim of this study was to investigate the role of selenium, ascorbic acid, beta-carotene, and alpha-tocopherol on D-GaIN-induced liver injury of rats by morphological and immunohistochemical means. In this study, Sprague-Dawley female rats were divided into four groups. Group I consists of rats injected physiologic saline solution intraperitoneally. Group II consists of rats given selenium (0.2 mg/kg per day), ascorbic acid (100 mg/kg per day), beta-carotene (15 mg/kg per day), and alpha-tocopherol (100 mg/kg per day) for 3 days via gavage method. Group III consists of the single dose of D-GaIN (500 mg/kg)-injected animals. Group IV are the D-GaIN-injected animals given the same antioxidant combination. In situ terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick-end labeling (TUNEL) assay was applied to determine apoptosis for paraffin sections of the liver samples. Moreover, caspase-3 and proliferating cell nuclear antigen antibody were applied for paraffin sections. In the group given D-GaIN, apoptotic cells with TUNEL assays and caspase-3 activity, which are liver injury markers induced by D-GaIN, the hepatocyte proliferation with cell proliferation assay increased. However, selenium and other three antioxidants combination clearly suppressed an increase in apoptotic cells with TUNEL assay and caspase-3 activity. In addition, it suppressed D-GaIN-induced cell proliferation in the liver. As a result, these results indicate that selenium and three naturally occurring antioxidants shows a protective effect against liver injury induced by D-GaIN. These results suggest that supplementation with the combination of selenium, ascorbic acid, beta-carotene, and alpha-tocopherol may help prevent the development of liver injury

Efficacy of single-chamber microbial fuel cells for removal of cadmium and zinc with simultaneous electricity production

Simultaneous high power generation (3.6 W/m2) and high Cd (90%) and Zn (97%) removal efficiencies were demonstrated in a single chamber air-cathode microbial fuel cell (MFC). The maximum tolerable concentrations (MTCs) were estimated as 200 μM for Cd and 400 μM for Zn. Increasing the concentrations of Cd to 300 μM and Zn to 500 μM resulted in voltage drops by 71 and 74%, respectively. Feeding the MFCs with incrementally increased Cd and Zn concentrations resulted in much slower reduction in voltage output. Biosorption and sulfides precipitation are the major mechanisms for the heavy metal removal in the MFCs.US National Science Foundation (CBET 0955124)

Protective effects of antioxidant combination against D-galactosamine-induced kidney injury in rats

The protective effects of an antioxidant combination in kidney injury induced by the injection of D-galactosamine (D-GaIN) were examined in the present study. Sprague Dawley female rats were used and divided into four groups as follows: (1) animals injected physiological saline solution, intraperitoneally, (2) animals treated with the combination of ascorbic acid (100 mg kg(-1) day(-1)), beta-carotene (15 mg kg(-1) day(-1)), alpha-tocopherol (100 mg kg(-1) day(-1)), and sodium selenate (0.2 mg kg(-1) day(-1)) for three days orally, (3) rats injected D-GaIN (500 mg kg(-1)) intraperitoneally as a single dose, and (4) animals treated with the antioxidant combination for three days, then injected D-GaIN. The tissue and blood samples of animals were collected for morphological and biochemical evaluations. Histopathological injury in kidney tissues was observed together with a significant increase in tissue lipid peroxidation (LPO) level, myeloperoxidase (MPO), lactate dehydrogenase, catalase and Superoxide dismutase (SOD) activities, and serum creatinine and urea levels, and a significant decrease in glutathione level and glutathione peroxidase activity in D-GAIN injected rats. However, a decrease in the degenerative changes was detected in the kidney tissue of D-GaIN+antioxidant group, and biochemical results showed reversed effects. In conclusion, it seems reasonable to conclude that the treatment of the antioxidant combination has a protective effect on D-GaIN-induced kidney injury of rats. Copyright (C) 2010 John Wiley & Sons, Ltd

Bioelectricity generation using human neuronal-like cells in single chamber biofuel cells

Bioelectricity production was achieved using human neuronal-like cells called SH-SY5Y cell line in single-chamber air-cathode fuel cells. Dulbecco's Modified Eagle's medium was used as the carbon source. SH-SY5Y cells grown on carbon cloth were used as anode in the experiments. The voltage was 96 mV using 980 Ω external resistance. Voltage levels decreased when the medium was replaced with medium containing 4.5 g L−1 of glucose. Maximum power density, current density and Coulombic efficiency were measured as 12 mW m−2, 0.013 mA cm−2 and 15%, respectively. Anode biofilm was examined using a multipotentiostat, and cyclic voltammetry results showed redox activity. The output of the fuel cell was connected to a circuit to power LEDs, by using the circuit as a voltage-controlled current source. The results demonstrated for the first time that human neuronal-like cells can generate bioelectricity in a fuel cell to power LEDs