Effects of iron on fatty acid and astaxanthin accumulation in mixotrophic Chromochloris zofingiensis

The integration of oleaginous microalgae cultivation with high-value products is considered a low-cost approach for manufacturing algae-based biodiesel. The objective of this study was to investigate the potential of using Fe(II) to produce fatty acids and astaxanthin in mixotrophic Chromochloris zofingiensis. Fatty acid biosynthesis was less sensitive than astaxanthin formation to the changes in Fe²⁺ concentrations. However, the enhancement and inhibition of fatty acids formation were concomitant with an increase and a decrease in the production of astaxanthin, respectively. The highest contents of astaxanthin and total fatty acids were simultaneously obtained at 0.2 mM Fe²⁺ with the corresponding values of 2.2 mg g^?1 (i.e., 25.8 mg l^?1) and 41.8 % dry weight (i.e., 5 g l^?1).     

Evaluation of indigenous microalgal isolate Chlorella sp. FC2 IITG as a cell factory for biodiesel production and scale up in outdoor conditions

The present study reports evaluation of an indigenous microalgal isolate Chlorella sp. FC2 IITG as a potential candidate for biodiesel production. Characterization of the strain was performed under photoautotrophic, heterotrophic, and mixotrophic cultivation conditions. Further, an open-pond cultivation of the strain under outdoor conditions was demonstrated to evaluate growth performance and lipid productivity under fluctuating environmental parameters and in the presence of potential contaminants. The key findings were: (1) the difference in cultivation conditions resulted in significant variation in the biomass productivity (73–114 mg l^?1 day^?1) and total lipid productivity (35.02–50.42 mg l^?1 day^?1) of the strain; (2) nitrate and phosphate starvation were found to be the triggers for lipid accumulation in the cell mass; (3) open-pond cultivation of the strain under outdoor conditions resulted in biomass productivity of 44 mg l^?1 day^?1 and total lipid productivity of 10.7 mg l^?1 day^?1; (4) a maximum detectable bacterial contamination of 7 % of the total number of cells was recorded in an open-pond system; and (5) fatty acid profiling revealed abundance of palmitic acid (C16:0), oleic acid (C18:1) and linoleic acid (C18:2), which are considered to be the key elements for suitable quality biodiesel.     

Comparison of pigment and proximate compositions of <Emphasis Type="Italic">Tisochrysis lutea</Emphasis> in phototrophic and mixotrophic cultures

Pigment contents and proximate compositions are important traits to evaluate the nutritional value of microalgae. The environmental condition and nutrient availability in the culture medium are hypothesised to regulate algal colour, nutritional composition and production. This study aimed to compare the pigment and proximate compositions in Tisochrysis lutea under phototrophic and mixotrophic conditions in an attempt to improve algal product quality. Algae were grown in the phototrophic and mixotrophic conditions at 50 μmol photons m^?2 s^?1 for 12 h daily, but 50 mM glycerol was added as a carbon source in the mixotrophic culture. The pigment contents in algae significantly increased in the mixotrophic condition, and the contents of chlorophylls a and c and carotenoids increased nearly 60 % compared with those in the phototrophic condition. The contents of saturated and polyunsaturated fatty acids in algae were significantly higher while the content of monounsaturated fatty acids was significantly lower in the mixotrophic condition than those in the phototrophic condition. Although the contents of protein, lipid and carbohydrate in T. lutea were not different, their overall production was significantly enhanced in the mixotrophic condition compared to the phototrophic condition. This study indicates that mixotrophic culture promotes pigment and proximate production and the change of fatty acid profile in algae depends on the addition of organic carbon to the culture medium.     

Variations in the chemical composition of Costaria costata during harvest

In this study, variations in the chemical composition of Costaria costata collected during 3 months of the harvest period were analyzed. Moisture (4.94–10.50 %), ash (29.25–38.19 %), protein (9.77–18.15 %), lipid (0.60–2.21 %), crude fiber (4.45–5.68 %), alginate (22.49–29.13 %), fucoxanthin (0.07–0.32 mg g^?1), polyphenol (1.579–4.796 mg g^?1) were analyzed from dried alga. Six mineral elements were analyzed and the most abundant were calcium (6.64–11.56 mg g^?1) and magnesium (7.02–7.92 mg g^?1). Analysis of fatty acid composition indicated that the polyunsaturated fatty acids palmitoleic acid and linoleic acid were abundant in May and June, whereas the saturated fatty acid palmitic acid was abundant in July. Amino acid composition was also analyzed and the most abundant amino acids were aspartic acid, glutamic acid, glycine, and alanine. The ratio of mannuronic acid to guluronic acid of alginate was 2.57, 2.17, and 1.66 in May, June, and July, respectively. The gel strength of alginate was 1,449.0, 1,935.0, and 980.5 g cm^?1 in May, June, and July, respectively. The results of this study indicate that C. costata is an excellent resource that provides extensively applications in the industrial areas of chemicals, food, cosmetics, and pharmacy.     

Differential growth and biochemical composition of photoautotrophic and heterotrophic <Emphasis Type="Italic">Isochrysis maritima</Emphasis>: evaluation for use as aquaculture feed

The growth and biochemical composition of photoautotrophic and heterotrophic Isochrysis maritima in 50 L of Walne’s medium were compared. Heterotrophic I. maritima fed with 0.02 M glucose had a 4.6-fold higher maximum cell density (38.17 ± 0.23 × 10⁶ cells mL^?1) than photoautotrophic cells (8.29 ± 0.70 × 10⁶ cells mL^?1). The carbohydrate content was slightly higher in heterotrophic cells at all growth stages (mid-exponential, 40.8%; early stationary, 48.3%; and late stationary, 47.6%), but there was no significant effect on the protein content under either trophic condition. The total saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were higher under heterotrophic conditions than those under photoautotrophic conditions. However, because omega-3 PUFAs are the most essential element in feed nutrition, low results for eicosapentaenoic acid (EPA) (0.28 ± 0.06%) and docosahexaenoic acid (DHA) (3.22 ± 0.26%) in the heterotrophic cells compared to the photoautotrophic cells (EPA: 0.44 ± 0.11%; DHA: 8.58 ± 0.73%) plus a low omega-3/6 PUFAs ratio (heterotrophic: 0.16–0.47; photoautotrophic: 2.60–2.88) and high value of (SFA + MUFA)/PUFA (heterotrophic: 5.50–6.81; photoautotrophic: 2.64–3.60) showed that this species is not suitable for aquaculture feed when cultivated under heterotrophic conditions.     

Accumulation of rosmarinic, chlorogenic and caffeic acids in in vitro cultures of Eryngium planum L.

Eryngium planum L. cell and organ cultures were maintained on Murashige and Skoog media (MS), supplemented with exogenous hormones of different types and various concentrations for high biomass growth. The callus and cell suspension cultures were treated with increased sucrose concentration and/or elicited by methyl jasmonate for the enhancement of selected phenolic acids accumulation. Three phenolic acids, rosmarinic acid (RA), chlorogenic acid (CGA) and caffeic acid (CA), were detected by HPLC-DAD in those cultures. The sum of their content in the dry material was found to be higher in the shoot culture (3.95 mg g^?1), root culture (7.05 mg g^?1), callus (6.20 mg g^?1) and cell suspension (2.04 mg g^?1) than in the leaves (1.87 mg g^?1) and roots (0.76 mg g^?1) of intact plants. The major compound of in vitro cultures was always rosmarinic acid. The content of RA could be increased approximately threefold (16.24 mg g^?1) in the callus culture and approximately twofold (3.91 mg g^?1) in the cell suspension culture by elicitation with 100 μM methyl jasmonate (MeJA). The higher concentration of sucrose (S) in the medium (5, 6 %) led to over a twofold increase of CGA content in the callus culture (2.54 mg g^?1). The three mentioned phenolic acids have been found in E. planum undifferentiated and differentiated in vitro cultures for the first time.     

Lipid and total fatty acid productivity in photoautotrophic fresh water microalgae: screening studies towards biodiesel production

Microalgae are considered as a promising feedstock for biomass production. The selection of the most suitable species is based on several key parameters such as lipid and fatty acid productivity. In the present study, the growth of different microalgae strains was examined in freshwater media for photoautotrophs suited for large-scale applications to identify the most suitable medium for each species. In the optimal medium, Scenedesmus obliquus showed the highest biomass productivity measured as increase of cell dry weight (0.25 g cellu dry weight (CDW) L^?1 day^?1), while Botryococcus braunii showed the highest lipid and total fatty acid content (430 and 270 mg g^?1 CDW, respectively) among the tested species. Regarding lipid and total fatty acid productivity, S. obliquus was the most lipid and total fatty acid productive strain with 41 and 18 mg L^?1 day^?1 during the exponential phase, respectively. Additionally, the proportion of saturated and monounsaturated fatty acids increased with duration of the incubation in S. obliquus, while polyunsaturated fatty acids decreased. These results nominate S. obliquus as a promising microalga in order to serve as a feedstock for renewable energy production.     

Culture medium influence on growth,fatty acid,and pigment composition of <Emphasis Type="Italic">Choricystis minor</Emphasis> var. <Emphasis Type="Italic">minor</Emphasis>: a suitable microalga for biodiesel production

The purposes of this study were to assess the influence of culture medium on biomass production, fatty acid, and pigment composition of Choricystis minor var. minor and to evaluate the use of this microalga as a source of fatty raw material for biodiesel production. Cultures of C. minor var. minor were grown using WC (Wright’s cryptophyte) and BBM (Bold’s Basal medium) media. BBM medium produced more biomass (984.3 mg L^?1) compared to the WC medium (525.7 mg L^?1). Despite this result, WC medium produced a higher methyl ester yield for biodiesel production than the BBM medium (170.0 and 90.2 mg g^?1 of biomass, respectively). The average percentage of fatty acids obtained using the WC medium (17.0 %) was similar to soybean (18.0 %) and with similar biomass fatty acid profile. However, for pigment production, carotenoids and chlorophyll concentrations were twice as high when using the BBM medium.     

Effects of carbon source and light intensity on the growth and total lipid production of three microalgae under different culture conditions

We attempted to enhance the growth and total lipid production of three microalgal species, Isochrysis galbana LB987, Nannochloropsis oculata CCAP849/1, and Dunaliella salina, which are capable of accumulating high content of lipid in cells. Low nitrogen concentration under photoautotrophic conditions stimulated total lipid production, but a decreasing total lipid content and an increasing biomass were observed with increasing nitrogen concentration. Among the different carbon sources tested for heterotrophic cultivation, glucose improved the growth of all three strains. The optimal glucose concentration for growth of I. galbana LB987 and N. oculata CCAP849/1 was 0.02 M, and that of D. salina was 0.05 M. Enhanced growth occurred when they were cultivated under heterotrophic or mixotrophic conditions compared with photoautotrophic conditions. Meanwhile, high total lipid accumulation in cells occurred when they were cultivated under photoautotrophic or mixotrophic conditions. During mixotrophic cultivation, biomass production was not affected significantly by light intensity; however, both chlorophyll concentration and total lipid content increased dramatically with increasing light intensity up to 150 µmol/m²/s. The amount and composition ratio of saturated and unsaturated fatty acids in cells were different from each other depending on both species and light intensity. The highest accumulation of total fatty acid (C16–C18) among the three strains was found from cells of N. oculata CCAP849/1, which indicates that this species can be used as a source for production of biodiesel.     

Effects of additional Mg2+ on the growth,lipid production,and fatty acid composition of Monoraphidium sp. FXY-10 under different culture conditions

The effects of supplementing the culture medium with Mg²⁺ on the growth, lipid production, and fatty acid composition of Monoraphidium sp. FXY-10 were studied under photoautotrophic, heterotrophic, and mixotrophic conditions. Under the photoautotrophic condition, microalgae supplemented with 100 μM Mg²⁺ grew significantly better than the control group and exhibited a secondary growth state. The final cell density was 1.25-fold higher than that of the control group (2.98 g L^?1), and the peak lipid content reached 59.8 % (control group 52.3 %). Culture under the heterotrophic condition did not significantly increase the growth rate, but the experimental group (100 μM Mg²⁺ supplementation) achieved a 37.03 % lipid content compared to 28.47 % by the control group. The lipid productivity of the experimental group (100 μM Mg²⁺ supplementation) was higher, reaching 65.93 mg L^?1 day^?1 compared with 56.10 mg L^?1 day^?1 for the group without additional Mg²⁺. Under the mixotrophic condition, the experimental group achieved a final density of 3.10 g L^?1, which was higher than that of the control group (2.98 g L^?1). There was also no variation in fatty acid composition between the experimental group and the control group. Under the heterotrophic and mixotrophic conditions, the experimental group produced more than 50% saturated fatty and mono-unsaturated fatty acids, and the degree of unsaturation was <137. This result was relatively lower than that of the control.     

Biomass and oil content of Chlorella sp., Haematococcus sp., Nannochloris sp. and Scenedesmus sp. under mixotrophic growth conditions in the presence of technical glycerol

The growth of algae strains Chlorella sp., Haematococcus sp., Nannochloris sp. and Scenedesmus sp. under mixotrophic conditions in the presence of different concentrations of technical glycerol was investigated with the aim of increasing biomass growth and algae oil content. The highest concentration of lipid obtained in media with 5 g L^?1 glycerol for Chlorella sp., Scenedesmus sp., Nannochloris sp. and Haematococcus sp. was 17.77, 22.34, 27.55 and 34.22 % larger than during the autotrophic growth of these species. Increases in triacylglycerols of up to ten times was observed for Scenedesmus sp. under mixotrophic conditions (using 10 g L^?1 glycerol), whereas an increase of 2.28 times was found for Haematococcus sp. The content of saturated fatty acids of Scenedesmus, Chlorella, Haematococcus and Nannochloris was 67.11, 34.63, 23.39 and 24.23 %, and the amount of unsaturated fatty acids was 32.9, 65.06, 79.61 and 75.78 % of total fatty acids, respectively. Growth on technical glycerol of these strains with light produced higher biomass concentrations and lipid content compared with autotrophic growth. The fatty acid content of oils from these species suggests their potential use as biodiesel feedstock.     

Influence of an intermittent food supply on energy storage by the subpolar deposit feeder Yoldia hyperborea (Bivalvia: Nuculanidae)

Food supply for deposit feeders varies from highly seasonal phytodetritus to a steady source of older organic matter, resulting in contrasting patterns of nutrient uptake and storage. To identify patterns in energy storage and feeding behaviour driven by different food conditions for the circumpolar deposit-feeding protobranch bivalve Yoldia hyperborea, we measured variations in cytological (digestive cell height) and biochemical (lipid class, fatty acid, glycogen, and protein content) components during controlled experiments. Three treatments with organisms in sediment with high refractory organic matter (12 % OM) were exposed to different feeding regimes resembling (a) the annual spring bloom settlement, (b) low food availability during winter, and (c) sporadic resuspension events. Yoldia exposed to a diatom-supplemented diet showed significantly higher mean values for digestive cell height (28.44 μm), glycogen (30.4 mg g^?1 dry mass, DM), diatom-specific fatty acids, and total lipid (TL) levels (14.4 mg g^?1 DM), but lower protein concentrations, than in non-supplemented treatments (digestive cell height 20.34 μm; glycogen 9.23 mg g^?1 DM; TL 6.7 mg g^?1 DM). All analyses showed no effect of resuspension events; thus, it was unlikely that resuspension improved sediment nutritional value. In the absence of recently deposited diatoms, Y. hyperborea did not increase nutrient storage, suggesting that significant amounts of older refractory OM are not used for growth or reproduction. The rapid storage of nutrients derived from diatoms demonstrates the role of seasonal episodic events of settling algae in the nutrition of subpolar Y. hyperborea and in the transfer of energy from the water column to the benthos.     

Optimization of growth and fatty acid composition of a unicellular marine picoplankton,Nannochloropsis sp., with enriched carbon sources

A unicellular marine picoplankton, Nannochloropsis sp., was grown under CO₂-enriched photoautotrophic or/and acetate-added mixotrophic conditions. Photoautotrophic conditions with enriched CO₂ of 2800 l CO₂ l^–1 and aeration gave the highest biomass yield (634 mg dry wt l^–1), the highest total lipid content (9% of dry wt), total fatty acids (64 mg g^–1 dry wt), polyunsaturated fatty acids (35% total fatty acids) and eicosapentaenoic acid (EPA, 20:53) (16 mg g^–1 dry wt or 25% of total fatty acids). Mixotrophic cultures gave a greater protein content but less carbohydrates. Adding sodium acetate (2 mM) decreased the amounts of the total fatty acids and EPA. Elevation of CO₂ in photoautotrophic culture thus enhances growth and raises the production of EPA in Nannochloropsis sp.     

Accumulation of hydroxybenzoic acids and other biologically active phenolic acids in shoot and callus cultures of Aronia melanocarpa (Michx.) Elliott (black chokeberry)

Phenolic acids are plant metabolites important in phytotherapy and also in cosmetology. In this study, proliferating shoot and callus cultures of Aronia melanocarpa were established and maintained on Linsmaier and Skoog (L-S) medium containing different levels of α-naphthaleneacetic acid (NAA) and 6-benzyladenine (BA), ranging from 0.1 to 3.0 mg l^?1. Methanolic extracts from the biomass of these cultures and from the fruits of soil-grown plants were used to determine the amounts of free phenolic acids and cinnamic acid using the high-performance liquid chromatography (HPLC) method. Out of a total of twelve analyzed compounds, all of the extracts contained four of them: caffeic acid, p-hydroxybenzoic acid, syringic acid, and vanillic acid. Moreover, shoot extracts also contained salicylic acid (o-hydroxybenzoic acid), while callus extracts contained p-coumaric acid. On the other hand, fruit extracts also contained both salicylic acid and p-coumaric acid. The total amount of the analyzed compounds in extracts from both shoot and callus cultures depended on the L-S medium used, and varied between 103.05 and 150.95 mg 100 g^?1 dry weight (DW), and between 50.23 and 81.56 mg 100 g^?1 DW, respectively. Both types of culture contained higher levels of phenolic acids than the fruit extracts (32.43 mg 100 g^?1 DW). In shoot cultures, p-hydroxybenzoic acid and salicylic acid were the predominant metabolites (reaching 55.14 and 78.25 mg 100 g^?1 DW, respectively), while in callus cultures, p-hydroxybenzoic acid (25.60 mg 100 g^?1 DW) and syringic acid (41.20 mg 100 g^?1 DW) were the main compounds. In fruit extracts, salicylic acid (15.60 mg 100 g^?1 DW) and p-hydroxybenzoic acid (5.29 mg 100 g^?1 DW) were predominant.     

Feeding elicitors and precursors enhance colchicine accumulation in morphogenic cultures of <Emphasis Type="Italic">Gloriosa superba</Emphasis> L.

Morphogenic cultures of Gloriosa superba were initiated on Murashige and Skoog’s medium fortified with 2 mg L^?1 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5 mg L^?1 naphthaleneacetic acid (NAA), 4% sucrose and 0.1% activated charcoal. To enhance the content of the alkaloid colchicine, morphogenic cultures were treated with different concentrations of abiotic elicitors like signalling compounds, metals, biotic elicitors, precursors and a combination of elicitors. Signalling molecules like acetyl salicylic acid (ASA) and sodium nitroprusside improved the production of colchicine. Abiotic elicitors have markedly (p?≤?0.05 or ≤?0.01) enhanced the colchicine content either at lower or higher concentrations. Among the metals, the highest amount of 11.67 mg of colchicine g^?1 dry wt was noticed at 60 mM rubidium chloride, followed by 60 mM NaCl (11.18 mg g^?1). Contrarily, in the presence of biotic elicitors such as Fusarium oxysporum, Alternaria solani, and Saccharomyces cerevisiae, colchicine content ranged only between 2 and 5.32 mg g^?1, but Bacillus subtilis repressed it. Among the aromatic amino acids, phenylalanine at 500 mg L^?1 influenced the highest accumulation of 19.48 mg g^?1 dry tissue, followed by tryptophan (12.47 mg g^?1), and tyrosine (9.87 mg g^?1), a direct precursor of colchicine biosynthesis, while intact tubers and leaves contained 4.65 and 4.16 mg of colchicine g^?1 dry tissue respectively. A combination of 10 µM AlCl₃ and 50 µM salicylic acid (SA) registered 17.34 mg g^?1 followed by 16.24 mg g^?1 tissue in presence of 1 µM HgCl₂ and 50 µM SA. The results suggest that the elicitor-stimulated colchicine accumulation was a stress response and can be exploited further for commercial production.     

Effect of elicitation and precursor feeding on accumulation of 20-hydroxyecdysone in <Emphasis Type="Italic">Achyranthes aspera</Emphasis> Linn. cell suspension cultures

20-Hydroxyecdysone is one of the most common ecdysteroids in plants with potential therapeutic applications. In this study, cell suspension cultures of Achyranthes aspera were raised in shake flasks to investigate the production of 20-hydroxyecdysone. The quantification and characterization of 20-hydroxyecdysone in the cultures were done by High performance liquid chromatography (HPLC) and Liquid Chromatography-quadrupole time-of- flight mass spectrometry (LC-Q-TOF) analyses. For raising the suspension, calli initiated from in vitro grown leaf explants were cultured in liquid Murashige and Skoog (MS) medium augmented with combinations of 2, 4-dichlorophenoxyacetic acid (1 mg L^?1) and α-naphthaleneacetic acid (1 mg L^?1). Maximum growth index of the cell suspension was 9.9, which was achieved during 20th day of culture (final phase of exponential growth). At this stage, the biomass accumulated was 1.09 ± 0.09 g dry weight (DW) and the 20-hydroxyecdysone concentration was 0.24 mg g^?1 DW. Eliciting the cultures with 0.6 mM Methyl jasmonate for 6 days; enhanced the production of 20-hydroxyecdysone production to 0.35 mg g^?1 DW. By augmenting the cultures with the precursors namely cholesterol (10 mg L^?1) and 7-dehydrocholesterol (10 mg L^?1), production of 20-hydroxyecdysone was boosted to 0.31 mg g^?1 DW and 0.28 mg g^?1 DW respectively.     

Pilot-scale supercritical carbon dioxide extractions for the recovery of triacylglycerols from microalgae: a practical tool for algal biofuels research

We describe the preliminary extractions from a pilot-scale supercritical carbon dioxide (SC-CO₂) extractor for the isolation of algal lipids suitable for small-scale conversion to liquid hydrocarbon fuels. Flowable oils were recovered from SC-CO₂ extractions of lyophilized Nannochloropsis granulata. The extracted oils were determined to be composed primarily of triacylglycerols (TAG) by liquid chromatography–mass spectrometry analysis. Gravimetric lipid yield was increased significantly from 15.56 to 28.45 mg g^?1 ash-free dry weight (AFDW) with an increase in temperature from 50°C to 70°C, at 35 MPa over 270 min. Varying pressure had no significant effect on lipid yield. Liquid chromatography–mass spectrometry analysis of the SC-SO₂ extracts indicated that the TAG profile remained constant regardless of extraction pressure, and analysis of fatty acid methyl esters (FAME) revealed a uniform profile throughout all extraction conditions. Our optimized gravimetric lipid yields from N. granulata (28.45 mg g^?1 AFDW) were approximately half of the yields obtained by Soxhlet extraction with hexane (57.53 mg g^?1 AFDW); however, the FAME yields were similar regardless of extraction technique (18.23 mg FAME g^?1 and 17.35 mg FAME g^?1 AFDW from SC-CO₂ extraction and hexane extraction, respectively). Further extractions with Botryococcus braunii indicated that fatty acid extraction by SC-CO₂ was as efficient as hexane extraction. These results highlight the suitability of SC-CO₂ for large-scale oil extraction of microalgae for biofuel or biojet analyses due to its selectivity for TAG extraction.     

Scale-up of adventitious root cultures of Echinacea angustifolia in a pilot-scale bioreactor for the production of biomass and caffeic acid derivatives

In an attempt to scale-up of adventitious root cultures of Echinacea angustifolia for the production of biomass and caffeic acid derivatives, i.e. echinacoside, chlorogenic acid, cichoric acid, caftaric acid, and cynarin, the effects of Murashige and Skoog (MS) medium dilutions, and initial sucrose concentrations were investigated in a 5-L airlift bioreactor. In addition, the kinetics of adventitious root growth and accumulation of secondary metabolites were also studied. The greatest root dry weight (6.50 g L^?l) and accumulation of total phenolics [22.06 mg g^?1 DW (dry weight)], total flavonoids (5.77 mg g^?1 DW) and total caffeic acid derivatives (10.63 mg g^?1 DW) were obtained at quarter-strength MS medium. Of the various gradients of sucrose tested, 5 % sucrose supplementation was regarded as an optimal concentration for enhancing productivity of biomass and bioactive compounds. Neither higher salt strength (3/4–2 MS) nor sucrose concentrations (7 and 9 %) showed promotive effect on root growth and metabolite production. The kinetic studies revealed that 4 weeks of culture period is the optimal time to achieve highest productivity of metabolites. Based on these results, a large-scale (20 L) and a pilot-scale (500 L) adventitious root culture system was established. In the pilot-scale bioreactor, adventitious roots were elicitor-treated with 100 μM methyl jasmonate (MJ) on day 28. After 1 week of elicitation, 1.75 kg dry root biomass was harvested containing 60.41 mg g^?1 DW of total phenolics, 16.45 mg g^?1 DW of total flavonoids, and 33.44 mg g^?1 DW of total caffeic acid derivatives. Among the caffeic acid derivatives, the accumulation of echinacoside (the major bioactive compound) in MJ-treated adventitious roots grown in the 500-L bioreactor was the highest (12.3 mg g^?1 DW), which is approximately threefold more than the non-MJ-treated roots cultured in 5- and 20-L bioreactors.     

24-Epibrassinolide alleviates salt-induced inhibition of productivity by increasing nutrients and compatible solutes accumulation and enhancing antioxidant system in wheat (Triticum aestivum L.)

Two wheat (Triticum aestivum L.) cultivars, Sids 1 and Giza 168, were grown under non-saline or saline conditions (4.7 and 9.4 dS m^?1) and were sprayed with 0.00, 0.05 and 0.10 mg l^?1 24-epibrassinolide (EBL). Salt stress markedly decreased plant productivity and N, P, and K uptake, particularly in Giza 168. A follow-up treatment with 0.1 mg l^?1 EBL detoxified the stress generated by salinity and considerably improved the above parameters, especially in Sids 1. Organic solutes (soluble sugars, free amino acids, proline and glycinebetaine), antioxidative enzymes (superoxide dismutase, peroxidase, catalase and glutathione reductase), antioxidant molecules (glutathione and ascorbate) and Ca and Mg levels were increased under saline condition, and these increases proved to be more significant in salt-stressed plants sprayed with EBL, particularly at 0.1 mg l^?1 EBL with Sids 1. Sodium concentration, lipid peroxidation, hydrogen peroxide content and electrolyte leakage were increased under salt stress and significantly decreased when 0.1 mg l^?1 EBL was sprayed. Clearly, EBL alleviates salt-induced inhibition of productivity by altering the physiological and biochemical properties of the plant.     

Production of biologically active phenolic acids in Aronia melanocarpa (Michx.) Elliott in vitro cultures cultivated on different variants of the Murashige and Skoog medium

Phenolic acids, both benzoic and cinnamic acid derivatives, are plant metabolites with high therapeutic and cosmetic values. Methanolic extracts from the biomass of shoot and callus cultures of Aronia melanocarpa growing on seven variants of the Murashige and Skoog (MS) medium with different concentrations of plant growth regulators, BA and NAA, ranging from 0.1 to 3.0 mg l^?1, were examined for the production of free phenolic acids and cinnamic acid using the high-performance liquid chromatography (HPLC) method. The extracts from the shoot and callus cultures were confirmed to contain five of the twelve compounds tested for: caffeic, p-coumaric, p-hydroxybenzoic, syringic and vanillic acids. The shoot extracts contained additionally salicylic acid. Both the total amounts and the amounts of individual compounds in either the shoot or callus extracts were dependent on the concentration of cytokinin and auxin in the MS medium variants. The total amounts in the shoot and callus cultures were in the range from 93.52 to 217.00 mg 100 g^?1 DW and from 47.11 to 83.83 mg 100 g^?1 DW, respectively. The amounts of individual compounds showed wide variation, from 1.31 to 91.86 mg 100 g^?1 DW in the shoot extracts, and from 2.58 to 40.16 mg 100 g^?1 DW in the callus extracts. Salicylic acid (max. 91.86 mg 100 g^?1 DW), p-coumaric acid (max. 62.39 mg 100 g^?1 DW) and p-hydroxybenzoic acid (max. 50.66 mg 100 g^?1 DW) dominated in the shoot extracts, while syringic acid (max. 40.16 mg 100 g^?1 DW) and p-hydroxybenzoic acid (max. 23.59 mg 100 g^?1 DW) were the main metabolites in the callus extracts. This is the first report on the quantitative analysis of benzoic and cinnamic acid derivatives in shoot and callus cultures of A. melanocarpa growing on MS-based media with different concentrations of selected plant growth regulators—BA and NAA. The obtained maximum amounts of some metabolites are of interest from a practical perspective.