Optimization and modeling of phenanthrene degradation by <Emphasis Type="Italic">Mycobacterium</Emphasis> sp. 6PY1 in a biphasic medium using response-surface methodology

In the present paper, the degradation of phenanthrene, a model polycyclic aromatic hydrocarbon compound, by the Mycobacterium strain 6PY1 was optimized in a biphasic culture medium. The optimization and modeling were performed using the design of experiments methodology. The temperature, the silicone oil/mineral salts medium volume ratio, and the initial cell concentration, were used as the central composite design parameters. In all experiments, the phenanthrene was degraded to undetectable levels. Response surface methodology was successfully employed to derive an empirical model describing the rate and time of degradation and to deduce the optimal degradation conditions. As a result of the optimization processes, the optimal responses for the degradation rate, the volumetric degradation rate, and the 90% degradation time were estimated to be 0.172 mg h⁻¹, 22 mg l⁻¹ h⁻¹, and 18 h, respectively.     

Enhanced Degradation of a Mixture of Polycyclic Aromatic Hydrocarbons by a Defined Microbial Consortium in a Two-Phase Partitioning Bioreactor

Biological treatment methods are effective at destroying polycyclic aromatic hydrocarbons (PAHs), and some of the highest rates of PAH degradation have been achieved using two-phase-partitioning bioreactors (TPPBs). TPPBs consist of a cell-containing aqueous phase and a biocompatible and immiscible organic phase that partitions toxic and/or recalcitrant substrates to the cells based on their metabolic demand and on maintaining the thermodynamic equilibrium of the system. In this study, the degradation of a 5-component mixture of high and low molecular weight PAHs by a defined microbial consortium of Sphingomonas aromaticivorans B0695 and Sphingomonas paucimobilis EPA505 in a TPPB was examined. The extremely low aqueous solubilities of the high molecular weight (HMW) PAHs significantly reduce their bioavailability to cells, not only in the environment, but in TPPBs as well. That is, in the two-phase system, the originally selected solvent, dodecane, was found to sequester the HMW PAHs from the cells in the aqueous phase due to the inherent high solubility of the hydrophobic compounds in this solvent. To circumvent this limitation, the initial PAH concentrations in dodecane were increased to sufficient levels in the aqueous phase to support degradation: LMW PAHs (naphthalene, phenanthrene) and fluoranthene were degraded completely in 8 h, while the HMW PAHs, pyrene and benzo[a]pyrene, were degraded by 64% and 11%, at rates of 42.9 mg l⁻¹ d⁻¹ and 7.5 mg l⁻¹ d⁻¹, respectively. Silicone oil has superior PAH partitioning abilities compared to dodecane for the HMW PAHs, and was used to improve the extent of degradation for the PAH mixture. Although silicone oil increased the bioavailability of the HMW PAHs and greater extents of biodegradation were observed, the rates of degradation were lower than that obtained in the TPPB employing dodecane.     

Adhesion to the hydrocarbon phase increases phenanthrene degradation by <Emphasis Type="Italic">Pseudomonas fluorescens</Emphasis> LP6a

Microbial adhesion is an important factor that can influence biodegradation of poorly water soluble hydrocarbons such as phenanthrene. This study examined how adhesion to an oil–water interface, as mediated by 1-dodecanol, enhanced phenanthrene biodegradation by Pseudomonas fluorescens LP6a. Phenanthrene was dissolved in heptamethylnonane and added to the aerobic aqueous growth medium to form a two phase mixture. 1-Dodecanol was non-toxic and furthermore could be biodegraded slowly by this strain. The alcohol promoted adhesion of the bacterial cells to the oil–water interface without significantly changing the interfacial or surface tension. Introducing 1-dodecanol at concentrations from 217 to 4,100 mg l⁻¹ increased phenanthrene biodegradation by about 30% after 120 h incubation. After 100 h incubation, cultures initially containing 120 or 160 mg l⁻¹ 1-dodecanol had mineralized >10% of the phenanthrene whereas those incubated without 1-dodecanol had mineralized only 4.5%. The production and accumulation of putative phenanthrene metabolites in the aqueous phase of cultures likewise increased in response to the addition of 1-dodecanol. The results suggest that enhanced adhesion of bacterial cells to the oil–water interface was the main factor responsible for enhanced biodegradation of phenanthrene to presumed polar metabolites and to CO₂.     

Phenanthrene stimulates the degradation of pyrene and fluoranthene by <Emphasis Type="Italic">Burkholderia</Emphasis> sp. VUN10013

Pyrene and fluoranthene, when supplied as the sole carbon source, were not degraded by Burkholderia sp. VUN10013. However, when added in a mixture with phenanthrene, both pyrene and fluoranthene were degraded in liquid broth and soil. The amounts of pyrene and fluoranthene in liquid media (initial concentrations of 50 mg l⁻¹ each) decreased to 42.1% and 41.1%, respectively, after 21 days. The amounts of pyrene and fluoranthene in soil (initial concentrations of 75 mg kg⁻¹ dry soil each) decreased to 25.8% and 12.1%, respectively, after 60 days. None of the high molecular weight (HMW) polycylic aromatic hydrocarbons (PAHs) tested adversely affected phenanthrene degradation by this bacterial strain and the amount of phenanthrene decreased rapidly within 3 and 15 days of incubation in liquid broth and soil, respectively. Anthracene also stimulated the degradation of pyrene or fluoranthene by Burkholderia sp. VUN10013, but to a lesser extent than phenanthrene. The extent of anthracene degradation decreased in the presence of these HMW PAHs.     

Novel evidence of cytochrome P450-catalyzed oxidation of phenanthrene in <Emphasis Type="Italic">Phanerochaete chrysosporium</Emphasis> under ligninolytic conditions

The presence of cytochrome P450 and P450-mediated phenanthrene oxidation in the white rot fungus Phanerochaete chrysosporium under ligninolytic condition was first demonstrated in this study. The carbon monoxide difference spectra indicated induction of P450 (130 pmol mg⁻¹ in the microsomal fraction) by phenanthrene. The microsomal P450 degraded phenanthrene with a NADPH-dependent activity of 0.44 ± 0.02 min⁻¹. One of major detectable metabolites of phenanthrene in the ligninolytic cultures and microsomal fractions was identified as phenanthrene trans-9,10-dihydrodiol. Piperonyl butoxide, a P450 inhibitor which had no effect on manganese peroxidase activity, significantly inhibited phenanthrene degradation and the trans-9,10-dihydrodiol formation in both intact cultures and microsomal fractions. Furthermore, phenanthrene was also efficiently degraded by the extracellular fraction with high manganese peroxidase activity. These results indicate important roles of both manganese peroxidase and cytochrome P450 in phenanthrene metabolism by ligninolytic P. chrysosporium.     

Characterization of selected actinomycetes degrading polyaromatic hydrocarbons in liquid culture and spiked soil

Summary Five strains of the Rhodococcus and Gordonia genera were evaluated for their potential use in bioremediation of polycyclic aromatic hydrocarbons (PAH) with or without another substrate (co-substrate). Their ability to produce biosurfactants or to degrade phenanthrene when growing on glucose, hexadecane and rapeseed oil was tested in liquid medium at 30 °C. All strains showed biosurfactant activity. The highest reduction in surface tension was recorded in whole cultures of Rhodococcus sp. DSM 44126 (23.1%) and R. erythropolis DSM 1069 (21.1%) grown on hexadecane and Gordonia sp. APB (20.4%) and R. erythropolis TA57 (18.2%) grown on rapeseed oil. Cultures of Gordonia sp. APB and G. rubripertincta formed emulsions when grown on rapeseed oil. After 14 days of incubation, Rhodococcus sp. DSM 44126 degraded phenanthrene (initial concentration 100 μg ml⁻¹) as sole carbon source (79.4%) and in the presence of hexadecane (80.6%), rapeseed oil (96.8%) and glucose (below the limit of detection). The other strains degraded less than 20%, and then with a co-substrate only. Rhodococcus sp. DSM 44126 was selected and its performance evaluated in soil spiked with a mixture of PAH (200 mg kg⁻¹). The effect of the addition of 0, 0.1 and 1% rapeseed oil as co-substrate was also tested. Inoculation enhanced the degradation of phenanthrene (55.7% and 95.2% with 0.1% oil and without oil respectively) and of anthracene (29.2% with 0.1% oil). Approximately 96% of anthracene and 62% of benzo(a)pyrene disappeared from the soil (inoculated and control) after 14 days and anthraquinone was detected as a metabolite. Rhodococcus sp. DSM 44126 was identified as Rhodococcus wratislaviensis by 16S rRNA sequencing and was able to degrade anthracene as sole carbon source in liquid culture.     

Production of red pigments byMonascus purpureus in solid-state culture

To maximize and sustain the productivity ofMonascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, 50%; pH, 6.0; inoculum size 1 x 10⁴ spore cells (grams of dry solid substrate)⁻¹; sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW (grams of initial dry substrate)⁻¹ and, 47.6 OD₅₀₀ (DCW grams)⁻¹ h⁻¹, respectively.     

Anaerobic utilization of phenanthrene by <Emphasis Type="Italic">Rhodopseudomonas palustris</Emphasis>

A phenanthrene-utilizing bacterium was anaerobically isolated and identified as Rhodopseudomonas palustris. It tolerated up to 100 mg phenanthrene l⁻¹ and degraded 50% of 50 mg phenanthrene l⁻¹ over 10 days. The presence of phenanthrene caused a prolonged lag phase (2–3 days) in cell growth and affected the photopigments biosynthesis, while DMSO (the solvent for phenanthrene) had no impact on cell growth. The cell surface hydrophobicity of the isolate was also increased.     

In vitro efficacy of <Emphasis Type="Italic">Hyptis suaveolens</Emphasis> L. (Poit.) essential oil on growth and morphogenesis of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="Italic">gladioli</Emphasis> (Massey) Snyder &; Hansen

Hyptis suaveolens L. (Poit.) essential oil was tested in vitro on the growth and morphogenesis of Fusarium oxysporum f.sp. gladioli (Massey) Snyder & Hansen, which causes Fusarium corm rot and yellows in various susceptible cultivars of gladiolus. The fungitoxicity of the oil was measured by percentage radial growth inhibition using the poisoned food technique (PF) and volatile activity assay (VA). The mycelial growth of the test fungus was completely inhibited at 0.998 and 0.748 μg ml⁻¹ concentration of oil in PF and VA, respectively. Essential oil was found to be fungicidal in nature at 1.247 and 0.998 μg ml⁻¹ concentration of oil in PF and VA, respectively. Determination of conidial germination in the presence of oil was also carried out and it was found that the oil exhibited 100% inhibition of conidial germination at 0.450 μg ml⁻¹ concentration. The effect of essential oil on the yield of mycelial weight was observed and it was found that at 0.873 μg ml⁻¹ concentration no mycelium was recorded and 100% inhibition was observed. The fungitoxicity of oil did not change even on exposure to 100°C temperature or to autoclaving, and the oil also retained its fungicidal nature even after storage of 24 months. The main changes observed under light microscopy after oil treatment were a decrease and loss of conidiation and anomalies in the hyphae such as a decrease in the diameter of hyphae and granulation of cytoplasm. The treatment of the oil also showed highly reduced cytoplasm in the hyphae, showing clear retraction of the cytoplasm from the hyphae and ultimately in some areas hyphae without cytoplasm were also found. GC-MS studies of the essential oil revealed that the oil consisted of 24 compounds with 1,8-cineole as major component accounting for 44.4% of the total constituents.     

Photolithotrophic cultivation of <Emphasis Type="Italic">Laminaria japonica</Emphasis> gametophyte cells in a silicone tubular membrane-aerated photobioreactor

Gametophyte cells of brown algae Laminaria japonica were employed both in a modified silicone tubular membrane-aerated photobioreactor (bubble-less cultivation mode) and a bubble-column photobioreactor (bubbling cultivation mode), to study different gas–liquid mixing modes on cell growth rate and cell physiological status. With an inoculum density of 50 mg DCW l⁻¹, in modified artificial Pacific seawater (APSW) medium at 13°C, light intensity of 60 μE m⁻² s⁻¹, light cycle of 16/8 h L/D, and aeration rate of 60 ml min⁻¹, the specific growth rates were 0.082 d⁻¹ for bubble-less mode and 0.070 d⁻¹ for bubbling mode with biomass, in the form of dry cell density, increasing 10.9 and 6.8 times, respectively, during the 36 days’ photolithotrophic cultivation. The specific oxygen evolution rate under bubble-less mode was 39.6% higher than under bubbling mode on the 18th day. The gametophyte cells grew in cell aggregates with clump sizes, at day 36, of 1.5 mm and 0.5 mm diameter under bubble-less and bubbling mode respectively and cell injury percentages of 5.1% and 21.1%, respectively. The silicone tubular membrane-aerated photobioreactor was better suited for the cultivation of fragile macroalgal gametophyte cells due to the absence of hydrodynamic shear stress caused by fluid turbulence and the presence of a bubble-less gas supply.     

Studies revealing bioremediation potential of the strain Burkholderia sp. GB-01 for abamectin contaminated soils

Burkholderia sp. GB-01 strain was used to study different factors affecting its growth for inoculum production and then evaluated for abamectin degradation in soil for optimization under various conditions. The efficiency of abamectin degradation in soil by strain GB-01 was seen to be dependent on soil pH, temperature, initial abamectin concentration, and inoculum size along with inoculation frequency. Induction studies showed that abamectin depletion was faster when degrading cells were induced by pre-exposure to abamectin. Experiments performed with varying concentrations (2–160 mg Kg⁻¹) of abamectin-spiked soils showed that strain GB-01 could effectively degrade abamectin over the range of 2–40 mg Kg⁻¹. The doses used were higher than the recommended dose for an agricultural application of abamectin, taking in account the over-use or spill situations. A cell density of approximately 10⁸ viable cells g⁻¹ dry weight of soil was found to be suitable for bioremediation over a temperature range of 30–35°C and soil pH 7.5–8.5. This is the first report on bacterial degradation of abamectin in soil by a Burkholderia species, and our results indicated that this bacterium may be useful for efficient removal of abamectin from contaminated soils.     

Degradation of polycyclic aromatic hydrocarbons in soil by a two-step sequential treatment

The objectives of this work were to isolate the microorganisms responsible for a previously observed degradation of polycyclic aromatic hydrocarbons (PAH) in soil and to test a method for cleaning a PAH-contaminated soil. An efficient PAH degrader was isolated from an agricultural soil and designated as Mycobacterium LP1. In liquid culture, it degraded phenanthrene (58%), pyrene (24%), anthracene (21%) and benzo(a)pyrene (10%) present in mixture (initial concentration 50 μg ml⁻¹ each) and phenanthrene (92%) and pyrene (94%) as sole carbon sources after 14 days of incubation at 30°C. In soil, Mycobacterium LP1 mineralised ¹⁴C-phenanthrene (45%) and ¹⁴C-pyrene (65%) after 10 days. The good ability of this Mycobacterium was combined with the benzo(a)pyrene oxidation effect obtained by 1% w/w rapeseed oil in a sequential treatment of a PAH-spiked soil (total PAH concentration 200 mg kg⁻¹). The first step was incubation with the bacterium for 12 days and the second step was the addition of the rapeseed oil after this time and a further incubation of 22 days. Phenanthrene (99%), pyrene (95%) and anthracene (99%) were mainly degraded in the first 12 days and a total of 85% of benzo(a)pyrene was transformed during the whole process. The feasibility of the method is discussed.     

Biomass production of<Emphasis Type="Italic">Anoectochilus formosanus</Emphasis> hayata in a bioreactor system

We investigated the factors that affect biomass production fromAnoectochilus formosanus in a bioreactor system. Those factors included inoculum size, initial sucrose concentration, media supplements, photosynthetic photon flux density (PPFD), and cuIturing methods. An inoculum size of 8 g L⁻¹ was most suitable for shoot proliferation; biomass accumulation was optimized when the medium was supplemented with 3% sucrose compared with sucrose-free media or those containing concentrations of 6% or 9%. This accumulation also was enhanced under a PPFD of 50 μmol m² s⁻¹. Likewise, the addition of coconut water (50 mL L⁻¹) plus activated charcoal (0.5 mg L⁻¹) to our Hyponex medium proved most beneficial. Comparative studies among three bioreactor systems — continuous immersion, raft (net), and temporary immersion (the ebb and flood system) — revealed that shoot proliferation and biomass accumulation were more efficient when culturing was performed under continuous immersion.     

Production and optimization of thermophilic alkaline protease in solid-state fermentation by <Emphasis Type="Italic">Streptomyces</Emphasis> sp. CN902

The purpose of the present research is to study the production of thermophilic alkaline protease by a local isolate, Streptomyces sp. CN902, under solid state fermentation (SSF). Optimum SSF parameters for enzyme production have been determined. Various locally available agro-industrial residues have been screened individually or as mixtures for alkaline protease production in SSF. The combination of wheat bran (WB) with chopped date stones (CDS) (5:5) proved to be an efficient mixture for protease production as it gave the highest enzyme activity (90.50 U g⁻¹) when compared to individual WB (74.50 U g⁻¹) or CDS (69.50 U g⁻¹) substrates. This mixed solid substrate was used for the production of protease from Streptomyces sp. CN902 under SSF. Maximal protease production (220.50 U g⁻¹) was obtained with an initial moisture content of 60%, an inoculum level of 1 × 10⁸ (spore g⁻¹ substrate) when incubated at 45°C for 5 days. Supplementation of WB and CDS mixtures with yeast extract as a nitrogen source further increased protease production to 245.50 U g⁻¹ under SSF. Our data demonstrated the usefulness of solid-state fermentation in the production of alkaline protease using WB and CDS mixtures as substrate. Moreover, this approach offered significant benefits due to abundant agro-industrial substrate availability and cheaper cost.     

Studies on the production of nigerloxin using agro-industrial residues by solid-state fermentation

Nigerloxin, a new and potent lipoxygenase inhibitor, was discovered in our laboratory through solid-state fermentation of wheat bran by Aspergillus niger V. Teigh (MTCC-5166). The aim of this study is to investigate the possibility of using different agro-industrial residues as nutritional supplements along with wheat bran to enhance the production of nigerloxin. Nigerloxin produced by SSF was quantified spectrophotometrically at 292 nm. The results indicate that the inhibitor production was influenced by the type of solid substrate supplemented, moisture content, pH and size of the inoculum. Individually optimized supplements were tested in different combinations to determine their effects on nigerloxin production. A twofold increase in the production of nigerloxin (4.9 ± 0.3 mg gds⁻¹) was achieved by supplementing wheat bran with 10% w/w sweet lemon peel and 5% v/w methanol at optimized process parameters, that is, an initial moisture content of 65% v/w and incubation period of 6 days with an initial inoculum size of 2 ml (8 × 10⁵ spores gds⁻¹). Nigerloxin production was stable between pH of 4 and 5.     

Concentration dependent growth/non-growth linked kinetics of endosulfan biodegradation by <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>

The rates of biodegradation of endosulfan by P. aeruginosa were determined with different initial endosulfan concentrations (10, 50, 100, 150, 200 and 250 mg l⁻¹) and different growth linked kinetic models were fitted at these concentrations. At 10 mg endosulfan l⁻¹, Monod no growth model was well fitted. Monod with growth model described the biodegradation pattern at an initial concentration of 50, 100 and 150 mg endosulfan l⁻¹. Significant increases of P. aeruginosa MN2B14 density in broth culture during incubation further support this result. Conversely, zero order kinetic model was well fitted into the biodegradation data if initial endosulfan concentration was ≥200 mg endosulfan l⁻¹. The kinetics of endosulfan biodegradation by P. aeruginosa MN2B14 in liquid broth was highly dependent upon its initial concentration. The results of this study could be employed for predicting the persistence of endosulfan in water environment containing P. aeruginosa as an endosulfan degrading bacterium.     

Enhanced fructooligosaccharides and inulinase production by a <Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">phaseoli</Emphasis> KM 24 mutant

Xanthomonas campestris pv phaseoli produced an extracellular endoinulinase (9.24 ± 0.03 U mL⁻¹) in an optimized medium comprising of 3% sucrose and 2.5% tryptone. X. campestris pv. phaseoli was further subjected to ethylmethanesulfonate mutagenesis and the resulting mutant, X. campestris pv. phaseoli KM 24 demonstrated inulinase production of 22.09 ± 0.03 U mL⁻¹ after 18 h, which was 2.4-fold higher than that of the wild type. Inulinase production by this mutant was scaled up using sucrose as a carbon source in a 5-L fermenter yielding maximum volumetric (21,865 U L⁻¹ h⁻¹) and specific (119,025 U g⁻¹ h⁻¹) productivities of inulinase after 18 h with an inulinase/invertase ratio of 2.6. A maximum FOS production of 11.9 g L⁻¹ h⁻¹ and specific productivity of 72 g g⁻¹ h⁻¹ FOS from inulin were observed in a fermenter, when the mutant was grown on medium containing 3% inulin and 2.5% tryptone. The detection of mono- and oligosaccharides in inulin hydrolysates by TLC analysis indicated the presence of an endoinulinase. This mutant has potential for large-scale production of inulinase and fructooligosaccharides.     

Evaluation of enrichments of sulfate reducing bacteria from pristine hydrothermal vents sediments as potential inoculum for reducing trichloroethylene

The evaluation of enrichments from pristine hydrothermal vents sediments on its capability of reducing trichloroethylene (TCE) under sulfate reducing conditions with lactate and volatile fatty acids (VFAs) as substrates was performed. Effect of the possible TCE biodegradation intermediates cis and trans 1,2 dichloroethenes on sulfate reduction (SR) was also evaluated. The influence of cyanocobalamin (CNB₁₂) and riboflavin (RF) on the SR and biodegradation of TCE was also determined. Sediments from the vents were incubated at 37°C and supplemented with 4 g l⁻¹ SO₄ ²⁻, lactate or VFAs and amended in the corresponding treatments with either CNB₁₂ or RF in separated experiments. A percentage of TCE removal of 86 (150 μmol l⁻¹ initial concentration) was attained coupled to 48% sulfate depletion with lactate as substrate. Up to 93% removal of TCE (300 μmol l⁻¹ initial concentration) and 40% of sulfate was reached for VFAs as electron donor. A combination of lactate and CNB₁₂ yielded the best SR. The overall results suggest a syntrophic association in this microbial community in which sulfate reducers, dehalogenating, and probably halorespiring bacteria may be interacting and taking advantage of the fermentation of substrates differently, but without interruption of SR in spite of the fact that TCE was always present. It was also clear that sulfate reduction must be established in the cultures before any degradation can occur. The microbial community present in these hydrothermal vents sediments could be a new source of inoculum for bioreactors designed for dechlorination purposes.     

Improved biodesulfurization of hydrodesulfurized diesel oil using Rhodococcus erythropolis and Gordonia sp.

Substituted benzothiophenes (BTs) and dibenzothiophenes (DBTs) remain in diesel oil following conventional desulfurization by hydrodesulfurization. A mixture of washed cells (13.6 g dry cell wt l⁻¹) of Rhodococcus erythropolis DS-3 and Gordonia sp. C-6 were employed to desulfurize hydrodesulfurized diesel oil; its sulfur content was reduced from 1.26 g l⁻¹ to 180 mg l⁻¹, approx 86% (w/w) of the total sulfur was removed from diesel oil after three cycles of biodesulfurization. The average desulfurization rate was 0.22 mg sulfur (g dry cell wt)⁻¹ h⁻¹. A bacterial mixture is therefore efficient for the practical biodesulfurization of diesel oil.     

Bioreactor application on adventitious root culture of <Emphasis Type="Italic">Astragalus membranaceus</Emphasis>

Astragalus membranaceus is one of the most widely used traditional medicinal herbs in China, but the time required to generate a useful product in the field production is long. The growth of adventitious root cultures was compared between cultures grown in solid, liquid, or a 5-L balloon-type bubble bioreactor. The maximum growth ratio (final dry weight/initial dry weight) was determined for adventitious roots grown in the bioreactor. Studies carried out to optimize biomass production of adventitious roots compared adventitious root growth from various inoculum root lengths, inoculum densities, and aeration volume in the bioreactors. The maximum growth ratio occurred in treatments with a 1.5-cm inoculum root length, with 30 g (fresh weight) of inoculum per bioreactor or with an aeration volume of 0.1 vvm (air volume/culture medium volume per min). The polysaccharide, saponin, and flavonoid content of roots from bioreactor-grown cultures were compared to roots from field-grown plants grown for 1 and 3 yr. Total polysaccharide content of adventitious roots in the bioreactor (30.0 mg g⁻¹ dry weight (DW)) was higher than the roots of 1-yr-old (13.8 mg g⁻¹ DW) and 3-yr-old (21.1 mg g⁻¹ DW) plants in the field. Total saponin (3.4 mg g⁻¹ DW) and flavonoid (6.4 mg g⁻¹ DW) contents were nearly identical to 3-yr-old roots and higher than that of 1-yr-old roots under field cultivation.