Fumihiko Hasumi

Regeneration of NADH and ketone hydrogenation by hydrogen with the combination of hydrogenase and alcohol dehydrogenase

The regeneration of nicotinamide-adenine dinucleotide (reduced form, NADH) by the reaction of NAD with hydrogen gas was carried out in the presence of the hydrogenase from Alcaligenes eutrophus. And the formations of alcohol, CO2, and 6-phospho-gluconate were observed by a combination of the above system and corresponding dehydrogenases. NADH was regenerated by hydrogen gas with the hydrogenase and recycled in these reactions.

Regeneration of NADH and ketone hydrogenation by hydrogen with the combination of hydrogenase and alcohol dehydrogenase. Scientific note.

The regeneration of nicotinamide-adenine dinucleotide (reduced form, NADH) by the reaction of NAD with hydrogen gas was carried out in the presence of the hydrogenase fromAlcaligenes eutrophus. And the formations of alcohol, CO2, and 6-phospho-gluconate were observed by a combination of the above system and corresponding dehydrogenases. NADH was regenerated by hydrogen gas with the hydrogenase and recycled in these reactions.

Synthesis of alanine and leucine by reductive amination of 2-oxoic acid with combination of hydrogenase and dehydrogenase.

Alanine synthesis by reductive amination of pyruvate was performed by the combination of NADH regeneration system and alanine dehydrogenase (AlaDH). The conversion of pyruvate to alanine was 99% after 1 h. Leucine synthesis was also carried out by the combination of NADH regeneration system and leucine dehydrogenase (LeuDH). The conversion of 4-methyl-2-oxovalerate to leucine was 60% after 1.5 h.

Synthesis of glutamate by reductive amination of 2-oxoglutarate with the combination of hydrogenase and glutamate dehydrogenase : scientific note

Glutamate synthesis by reductive amination of 2-oxoglutarate was performed by the combination of NADH regeneration system and glutamate dehydrogenase (GluDH). The conversion of 2-oxoglutamate to glutamate was 98% after 3 h, and the turnover number of NAD+was 17.

Hydrogenation of pyruvic acid by hydrogen with the combination of hydrogenase and lactate dehydrogenase

The regeneration of nicotinamide-adenine dinucleotide (reduced form NADH) by enzymatic systems is of great advantage in producing useful compounds for the simplification of certain systems, as reported previously [l-6]. In this study, hydrogenase from Akal~ms eutrophus was used for the regeneration of NADH from NAD+ with hydrogen gas as a reducing agent; hydrogenation of pyruvic acid was attempted by a combination of this system with lactate dehydrogenase, as shown in Scheme 1. The hydrogenase from Alcaligenes eutrophus was partly purified according to the literature [ 11. The activity (1 unit) of hydrogenase was to reduce 1 pmol of NAD’ for 1 min in the system containing hydrogenase and NADc (5.0X lop4 mol drn3) in 4.0 ml of a 5.0X 10e3 mol dmP3 phosphate buffer (pH 7.0) under 300 torr hydrogen pressure at 30 “C. Lactate dehydrogenase (LDH) from rabbit muscles was obtained from Sigma Co.

Biological heat generation by the cultivation ofAlternaria alternata in rice bran

Biological heat generation was observed whenAlternaria alternata was grown in rice bran. A temperature of more than 50°C was maintained for 25 d, and the maximum temperature was 56.5°C. After 30 d of cultivation, 55% of the energy of rice bran was liberated. The consumption rates of the lipids and sugar contained in rice bran increased with the increase of the maximum temperature during the cultivation ofA. alternata.

Prevention from Moth-Eating Damage by Respiration of Yeast Adsorbed by a Water-Absorbing Polymer.

With the objective to prevent moth-eating damage caused by insects, the system containing bakers yeast adsorbed by a water-absorbing polymer, Diawet US60, was prepared. The moth-eating damage caused by Attagenus unicolor japonicus was evaluated by use of a woolen cloth (2 cm2, 40 mg) with or without the system in 1 L glass vessel at 25 °C for 7 days. The moth-eating damage rates with and without the system were 3.3% and 54%, respectively, and the death rate of insect reached 100% with the system due to the respiration of yeasts.