Lactic acid bacteria-enclosing poly(epsilon-caprolactone) microcapsules as soil bioamendment.

Free plant growth-promoting bacteria in soil bioamendments (SBA) are easily outnumbered by competitors and predators in agricultural soils. Microencapsulation of the bacteria is an effective technique that provides a suitable microenvironment for their survival. In this study, we attempted to prepare poly(epsilon-caprolactone) (PCL) microcapsules enclosing lactic acid bacteria (LAB), a plant growth-promoting bacteria, using the solvent-evaporation method via water-in-oil-in-water (W/O/W) emulsion. Three preparation parameters in the emulsion system were optimized based on the lactic acid production activity of the encapsulated LAB. A sodium alginate aqueous solution suspending the bacteria, a dichloromethane solution with dissolved PCL, and a poly(vinyl alcohol) aqueous solution were used as the inner aqueous phase (W(i)), the oil phase (O), and the outer aqueous phase (W(o)), respectively. Suitable volume ratio of W(i) to O, concentration of sodium alginate in W(i), and the molecular weight of PCL in O were 0.1, 1.0%, and 40 kDa, respectively. The lactic acid production activity of the microcapsules prepared under the optimized conditions was approximately nine times higher than that of commercial SBA. Application to soil demonstrated that the microcapsules are effective in the removal of the root-knot nematodes.

Hot-compressed-water decomposed products from bamboo manifest a selective cytotoxicity against acute lymphoblastic leukemia cells.

We examined the effect of hot-compressed-water (HCW) extracted and fractionated bamboo products (named as fractions A and B) on the viability of human cultured cell lines, derived from leukemia patients and human peripheral blood lymphocytes, obtained from normal adults. Fraction A was composed of xylose, xylooligosaccharides and water-soluble lignin, determined by high-performance anion exchange chromatography and spectrophotometry. Fraction B was composed of glucose and celooligosaccharides. It was found that Fraction B expressed a negligible cytotoxic effect against leukemia cells, while Fraction A reduced markedly (in a dose-dependent manner) the viability of leukemia cell lines, derived from acute lymphoblastic leukemia (ALL)--Jurkat and MOLT-4. Fraction A did not influence the viability of leukemia cells, derived from myelogenous leukemia (ML-2) or lymphoma (SupT-1), as well as the viability of normal lymphocytes. Furthermore, microscopic examination of ALL-derived cells treated with Fraction A showed typical apoptotic morphological changes such as a condensation of nucleus and membrane blebing, as well as phosphatidylserine (PSer) exposure on the cell surface. The effect of decomposed products of commercially available xylan against ALL-derived Jurkat cells was significantly lower than that of Fraction A. These results suggest that the cytotoxic effect of Fraction A may be attributed to apoptosis, induced by xylooligosaccharides and it is specific for ALL-derived cells. We speculate that the water-soluble lignin is an important factor, potentiating the cytotoxic effect of xylan in HCW-extracts from bamboo.

Removal of nitrate-nitrogen from drinking water using bamboo powder charcoal.

The adsorption effectiveness of bamboo powder charcoal (BPC); made from the residual of Moso bamboo manufacturing; in removing nitrate-nitrogen from water has been investigated. Commercial activated carbon (CAC) was also used to compare the effectiveness of adsorption in removal of nitrate-nitrogen. The adsorption effectiveness of BPC was higher than that of CAC; regardless of the concentration of nitrate-nitrogen; in the range of 0-10 mg/l. The effect of temperature on adsorption by BPC and CAC in the range of 10-20 degrees C was also investigated. From the results, it was found that the temperature dependency of the adsorption effectiveness of BPC was weaker than that of CAC. This fact indicates that BPC can be an attractive option for the in situ treatment by adsorption of nitrate-nitrogen-contaminated underground and surface water.