Mikio Sakakibara

Medicinal uses of the mushroom Cordyceps militaris: Current state and prospects

Cordyceps militaris is a potential harbour of bio-metabolites for herbal drugs and evidences are available about its applications for revitalization of various systems of the body from ancient times. Amongst all the species, C. militaris is considered as the oldest source of some useful chemical constituents. Besides their popular applications for tonic medicine by the all stairs of the community, the constituents of C. militaris are now used extensively in modern systems of medicine. The current survey records the mysterious potentials of C. militaris are boosting up the present herbal treatments, as well as gearing up the green pharmacy revolution, in order to create a friendly environment with reasonable safety. Evidence showed that the active principles of C. militaris are beneficial to act as pro-sexual, anti-inflammatory, anti-oxidant/anti-aging, anti-tumour/anti-cancer/anti-leukemic, anti-proliferative, anti-metastatic, immunomodulatory, anti-microbial, anti-bacterial, anti-viral, anti-fungal, anti-protozoal, insecticidal, larvicidal, anti-fibrotic, steroidogenic, hypoglacaemic, hypolipidaemic, anti-angiogenetic, anti-diabetic, anti-HIV, anti-malarial, anti-fatigue, neuroprotective, liver-protective, reno-protective as well as pneumo-protective, let alone their other synergistic activities, which let it be marketable in the western countries as over-the-counter medicine. A number of culture techniques for this mushroom have been noticed, for example, storage/stock culture, pre-culture, popular/indigenous culture (spawn culture, husked rice culture and saw dust culture) and, special/laboratory culture (shaking culture, submerged culture, surface liquid culture and continuous/repeated batch culture). The prospects for herbal biotechnology regarding drug discovery using C. militaris delivering what it has promised are high, as the technology is now extremely more powerful than before. This study chiefly highlights the medicinal uses of the mushroom C. militaris including its culture techniques, also aiming to draw sufficient attention of the researchers to the frontier research needs in this context.

Influence of ultrasound irradiation on hydrolysis of sucrose catalyzed by invertase

Abstract Invertase-catalyzed hydrolysis reaction by sucrose under mild ultrasound irradiation was carried out in a 400-cm 3 bioreactor with a polyethylene film bottom, and the effects of ultrasound on the hydrolysis were investigated under a wide range of biochemical and physical exposure conditions. The effects were measured as a function of pH values, sucrose concentrations, and sound intensities. From these experimental results, an enhancement of reaction rate was observed in the low concentration region of sucrose. It was also clarified that in the high-concentration region of sucrose, continuous wave ultrasound had some substantial effects for the activity of the enzyme-catalytic reaction.

Effect of reaction conditions on phenol removal by polymerization and precipitation using Coprinus cinereus peroxidase

The quantitative relationships between removal efficiency of phenol and reaction conditions were investigated using Coprinus cinereus peroxidase. The most effective ratio of hydrogen peroxide to phenol was nearly 1/1 (mol/mol) at an adequate enzyme dose. 12.2 U of the enzyme was needed to remove 1 mg of phenol when our peroxidase preparation was used. At an insufficient peroxidase dose, the optimum pH value was 9.0, and lowering the reaction temperature led to the improvement of removal efficiency. At an excess peroxidase dose, almost 100% removal of phenol was obtained over a wide range of pH (5-9) and temperature (0-60 degrees C). Despite the presence of culture medium components, it was shown that Coprinus cinereus peroxidase had the same phenol polymerization performance as horseradish peroxidase or Arthromyces ramosus peroxidase.

A new approach for improving cordycepin productivity in surface liquid culture of Cordyceps militaris using high-energy ion beam irradiation.

Aims:  To obtain a higher cordycepin production using Cordyceps militaris mutant obtained by a new mutagenesis technique called ‘ion beam’.

Ultrasound-enhanced lactose hydrolysis in milk fermentation with Lactobacillus bulgaricus

The effects of ultrasonic irradiation during milk fermentation have been investigated in terms of the cell viability, β-galactosidase activity, the pH value of the culture medium, the degree of lactose hydrolysis and glucose content. The results showed that the ultrasonic irradiation caused the intracellular β-galactosidase to be released from the lactic acid bacteria cells. The released β-galactosidase showed a higher lactose hydrolysis activity than that in the cells. The β-galactosidase that was released to the medium has been more effectively used in pH-controlled fermentation. The results also showed that the continuous sonication caused the cell viability to decrease, but the viable cell count was again increased with static incubation after sonication. High degrees of lactose hydrolysis and high cell viabilities were obtained with the combination of pH-controlled sonicated fermentation and static incubation.

Ethanol production by repeated batch culture using yeast cells immobilized within porous cellulose carriers.

Ethanol was efficiently produced for 20 d by repeated batch culture using yeast cells immobilized in porous cellulose carriers. The physical structure of the carrier beads, which had small pores distributed on the outer surface and relatively large pores distributed in the interior, was found to be effective for cell immobilization. The effects of chemical modifications to the basic cellulose carrier on cell immobilization and ethanol production were also examined in repeated batch cultures. The chemical modifications had little effect on either cell immobilization or ethanol production.

Removal of bisphenol A by polymerization and precipitation method using Coprinus cinereus peroxidase

Bisphenol A was efficiently removed by the polymerization and precipitation method using Coprinus cinereus peroxidase. The removal efficiency was optimal between pH 9–10 and at 40 °C with a molar ratio of H2O2 to bisphenol A of about 2. To remove 100 mg bisphenol A l−1, peroxidase was required 5 U ml−1 at pH 7 and 25 °C and 3 U ml−1 at pH 10 and 40 °C.

Electrochemical reduction of immobilized NADP+ on a polymer modified electrode with a co-polymerized mediator

An electrode chemically modified by the amino group (Polyaminoaniline, PAA) was prepared and the immobilization of the co-polymerized viologen (Alg-V) and of NADP+ on the electrode, was investigated. NADP+ can not be reduced electrocatalytically on the viologen immobilized PAA-modified electrode. On the other hand, a cathodic peak in the cyclic voltammogram of the NADP+ immobilized PAA-modified electrode appeared at −1.2 V vs. SCE. corresponding to the reduction wave of free NADP+ on the electrode. The anodic wave of NADP dimer was not observed in the presence of Alg-V and ferredoxin NADP+ reductase (FRD). A conjugated reaction, coupling the electrochemical regeneration of NADPH on the electrode and a glutathione reductase reaction was performed using Alg-V, FRD, and oxidized form of glutathione. The conjugated redox reaction was successful with the NADP+ immobilized PAA-modified electrode. Under given conditions, the conversion ratio of reduced glutathione (GSH) from oxidized glutathione (GSSG) reached 100% after 2.0 h of incubation at 37°C and the concentration of GSH accumulated in the reaction mixture was 1.0 mM.

Citric Acid Production by Aspergillus niger Immobilised on Porous Cellulose Beads

Citric acid production using immobilised Aspergillus niger was studied. For the immobilisation, Viscopearl (porous cellulose beads) was used as the carrier. The immobilised ratio of the biomass to the carrier was controlled by changing the preculture periods. It significantly affected the production rate, the yield and the maximum concentration of citric acid. The optimum value of the preculture periods was 3 days in relation to the citric acid production. The initial sugar concentration also affected the citric acid production, and the optimum value was 100 g dm−3. Furthermore, the repeated batch culture was carried out using the immobilised biomass at several batch intervals. The optimum values of the batch interval were 6 days for the citric acid productivity and 8 days for the most cost effective process.

Effect of enzyme impurities on phenol removal by the method of polymerization and precipitation catalyzed by Coprinus cinereus peroxidase

Abstract. The removal of phenol by peroxidase-catalyzed polymerization was examined using the Coprinus cinereus peroxidases at different levels of impurity with respect to contamination. The phenol removal efficiency was improved by lowering the peroxidase purity. Acidic and high molecular weight proteins present as impurities in the peroxidase solution had some positive effect on the phenol-polymerizing reaction. The residual enzyme activity, either only in the solution or both in the solution and on the precipitate during the polymerizing reaction, was measured. The results indicate that the main effect of impurities in the peroxidase solution was the suppression of the adsorption of peroxidase molecules on the polymerized precipitate.