The spent medium after somatic embryo production has been analysed with respect to various enzymes, arabinogalactan protein and sandal oil. Apart from various hydrolases, a high level of peroxidase activity (32 200 U/ltre medium, with specific activity of 1.3417 U/μg protein) has been obtained. The peroxidase with an optimum activity at 50 °C was reasonably stable at 70 °C. The enzyme was active in the pH range 5–11, with an optimum at pH 6. The enzyme showed a Km of 10.91 mM and Vmax of 14.88 μM/min. Arabinogalactan protein (26–35 mg/l) has also been recovered from the extracellular medium. Sandal oil could not be detected by thin layer chromatography in the spent biomass or somatic embryos or the cell free medium, probably indicating its very low concentration.
Dr. Sanjay Pal, Das, S., and Dey, S., “Peroxidase and arabinogalactan protein as by-products during somatic embryo cultivation in air-lift bioreactor”, Process Biochemistry, vol. 38, pp. 1471–1477, 2003.