We demonstrated the feasibility of fedbatch operation using Clostridium acetobutylicum suspension culture as a biocatalyst for the continuous production of hydrogen. The optimum operating pH and temperature of the current cultivation system for hydrogen production were pH 6.0 and 37 degrees C, respectively. The volumetric loading of the bioreactor for hydrogen production can be as high as 650 m...

The histidine-containing phosphocarrier protein HPr is a central component of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), which transfers metabolic carbohydrates across the cell membrane in many bacterial species. In Gram-positive bacteria, phosphorylation of HPr at conserved serine 46 (P-Ser-HPr) plays several regulatory roles within the cell; the major regulatory effect of ...

Fenretinide [N-(4-hydroxyphenyl)retinamide (4-HPR)] is cytotoxic in many cancer cell types. Studies have shown that elevation of ceramide species plays a role in 4-HPR cytotoxicity. To determine 4-HPR activity in a multidrug-resistant cancer cell line as well as to study ceramide metabolism, MCF-7/AdrR cells (redesignated NCI/ADR-RES) were treated with 4-HPR and sphingolipids were analyzed. TLC...

The strictly anaerobic, Gram-positive bacterium, Thermoanaerobacterium aotearoense SCUT27, is capable of producing ethanol, hydrogen and lactic acid by directly fermenting glucan, xylan and various lignocellulosically derived sugars. By using non-metabolizable and metabolizable sugars as substrates, we found that cellobiose, galactose, arabinose and starch utilization was strongly inhibited by ...

HPr, a central component of the phosphoenolpyruvate-dependent phosphotransferase system, can exist in Escherichia coli in a phosphorylated (PHPr) and a nonphosphorylated form. We show that, beside the normal transfer of the phosphoryl group from PHPr to enzymes II and III, PHPr can phosphorylate other HPr molecules in an autocatalytic exchange reaction. The reaction is very fast but is inhibite...

14 This study investigates the mesophilic biohydrogen production from glucose using a strictly 15 anaerobic strain, Clostridium butyricum CWBI1009, immobilized in a trickling bed sequenced 16 batch reactor (TBSBR) packed with a Lantec HD Q-PAC ® packing material (132 ft2/ft3 specific 17 surface). The reactor was operated for 62 days. The main parameters measured here were 18 hydrogen compositio...

Hydrogen production by nitrogen-limited cultures of a thermophilic blue-green alga (cyanobacterium), Mastigocladus laminosus, was studied to develop the concept of a high-temperature biophotolysis system. Biophotolytic production of hydrogen by solar radiation was also demonstrated. Hydrogen consumption activity in these cultures was relatively high and is the present limiting factor on both th...

Childbearing and use of oral contraceptives are known to lower the risk of ovarian cancer, and it has been suggested that progesterone or progestin exposures play a role in these associations. The effects of progesterone may be mediated in part through the progesterone receptor, which exists in two functionally distinct protein isoforms, hPR-A and hPR-B. It is known that individuals carrying th...

The aim of this study was to investigate the interactions between cytokinin, sugar repression, and light in the senescence-related decline in photosynthetic enzymes of leaves. In transgenic tobacco (Nicotiana tabacum) plants that induce the production of cytokinin in senescing tissue, the age-dependent decline in NADH-dependent hydroxypyruvate reductase (HPR), ribulose-1,5-bisphosphate carboxyl...

Childbearing and use of oral contraceptives are known to lower the risk of ovarian cancer, and it has been suggested that progesterone or progestin exposures play a role in these associations. The effects of progesterone may be mediated in part through the progesterone receptor, which exists in two functionally distinct protein isoforms, hPR-A and hPR-B. It is known that individuals carrying th...