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Significance and Impact of the Study: A shortage of C4 hydrocarbon depending much on naptha-oil has become urgent problem due to rapid reduction of naphtha plants together with global energy revolution. Erythritol, obtained by fermentation, is a rare C4 polyol that can be converted to C4 hydrocarbons. Erythritol is considerably expensive than hydrocarbons, a reduction in cost is critical issue. To meet this, we proposed to utilize low-cost glycerol waste from bio-diesel fuel as a carbon source. Moniliella megachiliensis successfully converted glycerol waste to erythritol. This proposal is promising to obtain C4 hydrocarbon substitute, and concomitantly to dispose a large amount of glycerol waste discharged. AbstractThe number of naphtha plants is being reduced due to a worldwide shift in energy sources. Consequently, a shortage of chemical materials heavily dependent on naphtha-oil, especially C4 compounds such as butene and butane-diol, is an urgent issue in chemical manufacturing. Erythritol is a rare C4 compound produced by fermentation processes using glucose as the carbon source. Since erythritol is considerably more expensive than hydrocarbons derived from naphtha-oil, a reduction in its cost is critical. We found that Moniliella megachiliensis, a highly osmotolerant yeast strain, can utilize nonrefined glycerol waste derived from palm oil or beef tallow and convert it to erythritol. Cell growth on glycerol was almost the same as on glucose, and the cells could grow in up to 300 mg ml À1 glycerol. When 200 mg ml À1 nonrefined glycerol was supplied, the yield of erythritol from the glycerol was approx. 60%, which is slightly higher than that obtained using glucose. The cost of glycerol waste is considerably lower than that of glucose. Thus, the conversion of glycerol waste into valuable erythritol, proposed here, is attractive and promising from the viewpoint of ensuring a supply of C4 hydrocarbons and utilizing a waste natural resource.

The purpose of this study was to determine whether depletion of circulating neutrophils, using an antineutrophil monoclonal antibody (RP3), would attenuate ischemia/reperfusion injury in rat skeletal muscle. A 3- and 5-hr period of ischemia was induced unilaterally into the hindlimbs of rats; the isolated limbs were then reperfused for 24 hr after ischemia. The gastrocnemius muscle was then removed, and blood was taken simultaneously. The hematologic parameters were measured, muscle neutrophil sequestration was assessed by myeloperoxidase (MPO) activity, free radical production was evaluated by the tissue lipid peroxides (LPO) levels, muscle viability was assessed by tissue levels of adenosine triphosphate (ATP) and creatine phosphate (PCr) levels, and muscle wet/dry weights were determined. Treatment with RP3 selectively and sufficiently depleted the circulating neutrophil population, markedly reduced MPO, and significantly attenuated LPO and the tissue water content after both 3- and 5-hr of ischemia. After 3 hr of ischemia, ATP and PCr levels were significantly increased by neutrophil depletion; however, after 5 hr of ischemia, the same effect was not demonstrated. These results suggest that neutrophil depletion after 3 hr of ischemia restrains free radical production and edema formation, and also attenuates skeletal muscle ischemia reperfusion injury; however, after 5 hr of ischemia, ischemic damage was so severe, that neutrophil depletion did not reduce ischemia reperfusion injury.

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Two transketolase isogenes, MmTKL1 and MmTKL2, isolated from Moniliella megachiliensis were investigated for their roles in stress response and erythritol biosynthesis. The encoded proteins were highly homologous in amino acid sequence and domain structure. Two stress response elements (STREs) were found upstream of MmTKL1, while no STRE was found upstream of MmTKL2. In contrast, two Ap-1 elements were present upstream of MmTKL2, but none were detected upstream of MmTKL1. MmTKL2 partially complemented the aromatic amino acid auxotrophy of a Saccharomyces cerevisiae tkl1 deletion mutant, suggesting that at least one of the MmTKLs functioned as a transketolase in vivo. In response to short-term osmotic stress (20% glucose or 1.2 M NaCl) in Moniliella cells, MmTKL1 expression increased rapidly through the first 40 min before subsequently decreasing gradually, while MmTKL2 expression showed no significant change. In contrast, short-term oxidative stress (0.15 mM menadione) induced considerable increases in MmTKL2, while MmTKL1 expression remained low under the same conditions. Long-term osmotic stress (20% glucose) yielded increased expression of both genes starting at 12 h and continuing through 72 h. During either osmotic or oxidative stress, intracellular erythritol accumulation could clearly be correlated with the pattern of expression of either MmTKL1 or MmTKL2. These results strongly suggested that MmTKL1 is responsible primarily for the response to osmotic stress, while MmTKL2 is responsible primarily for the response to oxidative stress. Thus, we postulate that the two transketolase isoforms of M. megachiliensis play distinct and complementary roles in coordinating erythritol production in response to distinct environmental stresses.