Phenolics root products

To determine the effects of the constituents in the culture medium on phenolic (tannin) production in G. thunbergii hairy roots, two culture media were prepared one consisted of 1/2 MS major and minor elements (inorganic elements) and B5 vitamins (named as "1/2 MS vB5") and the other B5 major and minor elements and MS vitamins (B5 vMS). The hairy roots (ca 70 mg, fw) subcultured in 1/2 MS and B5 liquid media, respectively, were inoculated into four hormone-free liquid media (1/2 MS, B5, 1/2 MS vB5 and B5 vMS). After four week-culture in the dark at 25 C, the contents of 1, 2, 5, 6, 12 and 13 in these hairy roots were determined by HPLC (Table 5). 

In many plants, P deficiency also enhances production and root exudation of phenolic compounds (Fig. 5) (27,31,128-130). Increased bio.synthesis of pheno-... 

Isolated, crystallized and characterized. Pure commercial samples of each of the three phenols and p-benzoqulnone (VIII), the oxidation product of hydroqulnone (Included to evaluate the possible vivo oxidation of hydroqulnone), were tested In lettuce and leafy spurge root elongation tests and In leafy spurge cell cultures (Table II). 

Studies of pathogenic fungi suggested an explanation for the absence of inducer molecules in host root exudate. Quinones such as 2,6-DMBQ have been shown to be released by white rot fungi as terminal oxidation products of lignin model compounds (38). These findings substantiated previous reports (39-41) that laccases, phenol oxidases using 0 as the oxidant, are directly involved in... 

Other plants such as potatoes, cauliflower, cherries, and soybeans and several fungi may also be used as sources of peroxidase enzymes. Soybeans, in particular, may represent a valuable source of peroxidase because the enzyme is found in the seed coat, which is a waste product from soybean-based industries [90]. In this case, it may be possible to use the solid waste from the soybean industry to treat the wastewaters of various chemical industries. In fact, the direct use of raw soybean hulls to accomplish the removal of phenol and 2-chlorophenol has been demonstrated [105]. However, it should be noted that this type of approach would result in an increase in the amount of solid residues that must be disposed following treatment. Peroxidases extracted from tomato and water hyacinth plants were also used to polymerize phenolic substrates [106], Actual plant roots were also used for in vivo experiments of pollutant removal. The peroxidases studied accomplished good removal of the test substrate guaiacol and the plant roots precipitated the phenolic pollutants at the roots surface. It was suggested that plant roots be used as natural immobilized enzyme systems to remove phenolic compounds from aquatic systems and soils. The direct use of plant material as an enzyme source represents a very interesting alternative to the use of purified enzymes due to its potentially lower cost. However, further studies are needed to confirm the feasibility of such a process. 

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