Combined effects of probiotic fermentation and high-pressure extraction on the antioxidant, antimicrobial, and antimutagenic activities of deodeok (Codonopsis lanceolata).

This study was designed to evaluate the combined effects of probiotic fermentation and high-pressure extraction (HPE) on the functional properties of Codonopsis lanceolata. The ground C. lanceolata samples were anaerobically fermented with Lactobacillus acidophilus ADH, Bifidobacterium longum B6, Lactobacillus rhamnosus GG, or Lactobacillus paracasei at 37 degrees C for 10 days and subjected to 500 MPa at 50 degrees C for 30 min. The extraction yields of C. lanceolata samples were noticeably increased to 29-32% by HPE. The B. longum-fermented C. lanceolata samples extracted by high pressure (BLF-HPE) exhibited the highest antimicrobial activity (MIC < 14 mg/mL) against Listeria monocytogenes, Staphylococcus aureus, Shigella boydii, and Salmonella typhimurium. The nonfermented C. lanceolata samples extracted with high pressure (NF-HPE) had the highest total phenolic content (13.3 mg of GAE/g). The lowest effective concentrations (EC(50) and EC(0.5)) were 4.55 and 1.76 mg/mL, respectively, for NF-HPE extracts, indicating its highest antioxidant activity. The BLF-HPE and L. rhamnosus-fermented C. lanceolata samples extracted by high pressure (LRF-HPE) exhibited the highest antimutagenic activities in S. typhimurium TA 100, which were 82 and 83% inhibition, respectively. The use of probiotic fermentation and HPE can produce more biologically active compounds in C. lanceolata than the conventional solvent extraction method. The results provide pharmaceutically useful information for improving biological properties and an approach to drug discovery.

Lipid production in Porphyridium cruentum grown under different culture conditions.

Autotrophic growth of Porphyridium cruentum under 18:12 h and 12:12 h light:dark cycles showed the maximum cell concentration of 2.1 g-dry wt./L, whereas the specific growth rate, 0.042 (1/h), at 18:6 h is faster than that of 12:12 h, 0.031 (1/h), respectively. The highest lipid accumulation level, 19.3 (%, w/w), was achieved at 12:12 h cycle. Under dark cultivation condition with 10 g/L of glucose, the lipid accumulation in the cell was 10.9 (%, w/w), whereas the heterotrophic growth with glycerol as the carbon resource showed low level of cell concentration and lipid production, compared to that of glucose. The glucose was decided to be a suitable carbon resource for the heterotrophic growth of P. cruentum. The lipids from P. cruentum seemed be feasible for biodiesel production, because over 30% of the lipid was C16-C(18:1). The cultivation time and temperature were important factors to increase the maximum cell concentration. Extending the cultivation time helps maintain the maximum cell concentration, and higher lipid accumulation was achieved at 25 degrees C, compared to 35 degrees C. The fed-batch cultures showed that, under the light condition, the specific production rate was slightly decreased to 0.4% lipid/g-dry wt./day at the later stage, whereas, under the dark condition, the specific production rate was maintained to be a maximum value of 1.1% lipid/g-dry wt./day, even in the later stage of cultivation. The results indicate that the heterotrophic or 12:12 h cyclic mixotrophic growth of P. cruentum could be used for the production of biodiesel in long-term fed-batch cultivation of P. cruentum.