A genetic approach for microbial electrosynthesis system as biocommodities production platform.

Microbial electrosynthesis is a process that can produce biocommodities from the reduction of substrates with microbial catalysts and an external electron supply. This process is expected to become a new application of a cell factory for novel chemical production, wastewater treatment, and carbon capture and utilization. However, microbial electrosynthesis is still subject to several problems that need to be overcome for commercialization, so continuous development such as metabolic engineering is essential. The development of microbial electrosynthesis can open up new opportunities for sustainable biocommodities production platforms. This review provides significant information on the current state of MES development, focusing on extracellularly electron transfer and metabolic engineering.

Biological carbon monoxide conversion to acetate production by mixed culture.

To utilize waste CO for mixed culture gas fermentation, carbon sources (CO, CO2) and pH were optimized in the batch system to find out the center point and boundary of response surface method (RSM) for higher acetate (HAc) production (center points: 25% CO, 40% CO2, and pH 8). The concentrations of CO and CO2, and pH had significant effects on acetate production, but the pH was the most significant on the HAc production. The optimum condition for HAc production in the gas fermentation was 20.81% CO, 41.38% CO2, 37.81% N2, and pH 7.18. The continuous gas fermentation under the optimum condition obtained 1.66g/L of cell DW, 23.6g/L HAc, 3.11g/L propionate, and 3.42g/L ethanol.

Comparison of growth and pubertal progression in wild type female rats with different bedding types.

PURPOSE: Endocrine-disrupting chemicals interfere with the endocrine system and therefore affect growth and pubertal progression. The study aim was to compare the growth and pubertal progression in wild-type female rats with different bedding types. METHODS: Twenty 5-week-old female wild-type Sprague Dawley rats were randomly assigned to two groups with different bedding types: one group received wood shaving bedding, while a second group received corncob bedding. We determined crown-rump length and body weight as anthropometric measurements and assessed the serum growth hormone (GH) and estradiol levels. The gh1 mRNA expression levels were compared using quantitative real time transcription polymerase chain reaction. The estrous cycle was evaluated by vaginal smear. RESULTS: The anthropometric measurements were not significantly different between the two groups. The mean relative expression of the gh1 gene was lower in the corncob bedding group than that in the wood shaving group (P=0.768). Meanwhile serum GH and estradiol were increased in the wood shaving bedding group; however this difference was not statistically significant. The time to first estrus and the length of the estrous cycle were increased in the corncob bedding group; the proportion of normal estrous cycles was also decreased. These findings indicate irregularities in the estrous cycle. CONCLUSION: Endocrine-disrupting chemicals in corncob bedding might be associated with time to first estrus and length of the estrous cycle. Therefore, the type of bedding should be considered as a factor affecting pubertal progression in rodents.

Potentials of macroalgae as feedstocks for biorefinery.

Macroalgae, so-called seaweeds, have recently attracted attention as a possible feedstock for biorefinery. Since macroalgae contain various carbohydrates (which are distinctively different from those of terrestrial biomasses), thorough assessments of macroalgae-based refinery are essential to determine whether applying terrestrial-based technologies to macroalgae or developing completely new technologies is feasible. This comprehensive review was performed to show the potentials of macroalgae as biorefinery feedstocks. Their basic background information was introduced: taxonomical classification, habitat environment, and carbon reserve capacity. Their global production status showed that macroalgae can be mass-cultivated with currently available farming technology. Their various carbohydrate compositions implied that new microorganisms are needed to effectively saccharify macroalgal biomass. Up-to-date macroalgae conversion technologies for biochemicals and biofuels showed that molecular bioengineering would contribute to the success of macroalgae-based biorefinery. It was concluded that more research is required for the utilization of macroalgae as a new promising biomass for low-carbon economy.

The survivin suppressant YM155 potentiates chemosensitivity to gemcitabine in the human pancreatic cancer cell line MiaPaCa-2.

BACKGROUND: Survivin is a negative regulator of apoptosis. We evaluated the efficacy of YM155, a selective suppressant of survivin, in combination with gemcitabine in the pancreatic cancer cell line MiaPaCa-2. MATERIALS AND METHODS: Expression of survivin was demonstrated by immunoblotting. Cell cycle progression was determined by flow cytometric analysis. Cell viability was assayed using the trypan blue exclusion assay. RESULTS: Gemcitabine up-regulated survivin expression, whereas treatment with YM155 suppressed the expression of survivin. Concomitant treatment with YM155 enhanced chemosensitivity to gemcitabine, which was accompanied by a decrease in the expression of survivin. Knockdown of endogenous survivin via RNA interference also enhanced the sensitivity to gemcitabine. In addition, YM155 potentiated the antitumor effect of gemcitabine in xenograft tumors of MiaPaCa-2. CONCLUSION: YM155 potentiates chemosensitivity to gemcitabine in pancreatic cancer cells by suppressing the induction of survivin. Combination treatment with gemcitabine and YM155 may be a potential therapeutic strategy for the treatment of pancreatic cancer that warrants further clinical investigation.

Sudden failure of biological nitrogen and carbon removal in the full-scale pre-denitrification process treating cokes wastewater.

A full-scale pre-denitrification process treating cokes wastewater containing toxic compounds such as phenols, cyanides and thiocyanate has shown good performance in carbon and nitrogen removal. However, field operators have been having trouble with its instability without being able to identify the causes. To clarify the main cause of these sudden failures of the process, comprehensive studies were conducted on the pre-denitrification process using a lab-scale reactor system with real cokes wastewater. First, the shock loading effects of three major pollutants were investigated individually. As the loading amount of phenol increased to 600 mg/L, more COD, TOC and phenol itself were flowed into the aerobic reactor, but phenol itself did not inhibit nitrification and denitrification, owing to the effect of dilution and its rapid biodegradation. Higher loading of ammonia or thiocyanate slightly enhanced the removal efficiency of organic matter, but caused the final discharge concentration of total nitrogen to be above its legal limit of 60 mg-N/L. Meanwhile, continuous inflow of abnormal wastewater collected during unstable operation of the full-scale pre-denitrification process, caused a sudden failure of nitrogen removal in the lab-scale process, like the removal pattern of the full-scale one. This was discovered to be due to the lack of inorganic carbon in the aerobic reactor where autotrophic nitrification occurs.

Failed methotrexate treatment of cervical pregnancy. Predictive factors.

OBJECTIVE: To determine the risk factors when primary methotrexate treatment of cervical pregnancy fails. STUDY DESIGN: From January 1985 to December 1999, 32 women with cervical pregnancy were treated with methotrexate intramuscularly according to a repeated intramuscular injection protocol. For evaluation of the efficacy of therapy, pretreatment serum concentrations of human chorionic gonadotropin, size of the gestational mass, fetal cardiac activity and presence of fluid in the peritoneal cavity were measured. These findings were analyzed and compared in terms of success and failure by means of the chi 2 test, Fisher's exact test, receiver operating characteristic curve and Student's t test. RESULTS: There was no relation between the women's age, parity, size of the conceptus or presence of fluid in the peritoneal cavity to the efficacy of treatment. In a cervical pregnancy that presented with a serum human chorionic gonadotropin concentration of > or = 10,000 mIU/mL, fetal cardiac activity was associated with a higher failure rate of primary methotrexate treatment. CONCLUSION: In cervical pregnancies, a high serum human chorionic gonadotropin concentration and fetal cardiac activity were the most important factors associated with failure of treatment using methotrexate.