Electrodialytic separation of levulinic acid catalytically synthesized from woody biomass for use in microbial conversion.

Levulinic acid (LA) is produced by the catalytic conversion of a variety of woody biomass. To investigate the potential use of desalting electrodialysis (ED) for LA purification, electrodialytic separation of levulinate from both reagent and cedar-derived LA solution (40-160 g L-1 ) was demonstrated. When using reagent LA solution with pH5.0-6.0, the recovery rates of levulinate ranged from 68 to 99%, and the energy consumption for recovery of 1 kg of levulinate ranged from 0.18 to 0.27 kWh kg-1 . With cedar-derived LA solution (pH6.0), good agreement in levulinate recovery (88-99%), and energy consumption (0.18-0.22 kWh kg-1 ) were observed in comparison to the reagent LA solutions, although a longer operation time was required due to some impurities. The application of desalting ED was favorable for promoting microbial utilization of cedar-derived LA. From 0.5 mol L-1 of the ED-concentrated sodium levulinate solution, 95.6% of levulinate was recovered as LA calcium salt dihydrate by crystallization. This is the first report on ED application for LA recovery using more than 20 g L-1 LA solutions (40-160 g L-1 ). © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:448-453, 2017.

Draft Genome Sequence of Burkholderia stabilis LA20W, a Trehalose Producer That Uses Levulinic Acid as a Substrate.

Burkholderia stabilis LA20W produces trehalose using levulinic acid (LA) as a substrate. Here, we report the 7.97-Mb draft genome sequence of B. stabilis LA20W, which will be useful in investigations of the enzymes involved in LA metabolism and the mechanism of LA-induced trehalose production.

Cerebral blood flow and oxygen metabolism in patients with progressive dementia and amyotrophic lateral sclerosis.

We examined regional cerebral blood flow (rCBF) and oxygen metabolism (rCMRO2) in 10 patients with progressive dementia and amyotrophic lateral sclerosis (DALS), in 21 patients with classical amyotrophic lateral sclerosis without dementia (ALS), and in 17 controls. The mean rCBF and rCMRO2, especially in the anterior cerebral hemispheres, decreased significantly in patients with DALS. Patients with only ALS showed very mild changes in rCBF and rCMRO2 which were not significant except for the reductions in the sensorimotor area. Some rCBF and rCMRO2 values in ALS showed a significant correlation with some neurological signs indicating upper motor neuron involvement. These data suggest that hypoperfusion and oxygen hypometabolism in the anterior cerebral hemispheres have an etiological relationship with the deterioration of intellect in patients with progressive dementia and ALS. The metabolic and perfusional changes in the cerebral cortex of ALS patients are likely to depend on upper motor neuron involvement, but they are not confined to the neurons of the corticospinal tract.

Treatment of vascular dementia.

We report positron emission tomography (PET) findings of our patients with vascular dementia, asymptomatic cerebral infarction, and chronic cerebral circulatory insufficiency. According to the PET studies, it was suggested that frontal lobe hypoperfusion and hypometabolism play important roles in dementia caused by cerebral infarctions. It was also suggested that patients with subjective complaints associated with asymptomatic strokes and patients with chronic cerebral circulatory insufficiency already exhibited decreased cerebral circulation. Since therapeutic approaches to vascular dementia after its development are limited, active control of risk factors and prevention of recurrent stroke during the developmental process of vascular dementia are important. We review recent situations in prevention and treatment of vascular dementia.