Ultrasound-induced stress responses of Panax ginseng cells: Enzymatic browning and phenolics production

Jianyong Wu, Lidong Lin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

67 Citations (Scopus)

Abstract

The stress metabolic activities of Panax ginseng (P. ginseng) cells induced by low-energy ultrasound (US) were examined. P. ginseng cells in suspension cultures were exposed to 38.5 kHz US at two power levels (power density 13.7 and 61 mW/cm3) for 2 min. The US treatment caused rapid increase in the intracellular levels of polyphenol oxidase (PPO), peroxidase (PO), and phenylalanine ammonia lyase (PAL) and the production of polyphenols (PP) and phenolic compounds. The US-induced enzyme activities and phenolics production are part of plant stress responses to a mechanical stimulus. The much higher PPO activity and rate of PP production in the sonicated cultures are correlated to enzymatic browning, suggestive of physical damage and membrane permeabilization of the cells by US. The cells after sonication also showed decreased water content and cell volume, which may also be attributed to US-induced cell membrane permeabilization and water release. High-pressure shock and fluid shear stress arising from acoustic cavitation were regarded as the major causes of the responses. Nevertheless, the US exposure caused only temporary cell growth depression but no net loss of biomass yield of the culture.
Original languageEnglish
Pages (from-to)862-866
Number of pages5
JournalBiotechnology Progress
Volume18
Issue number4
DOIs
Publication statusPublished - 19 Aug 2002

ASJC Scopus subject areas

  • Biotechnology

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