Utilization of light for the assimilation of organic matter in Chlorella sp. VJ79

Chlorella sp. strain VJ79 was isolated from a total heterotrophic count of a wastewater collector. It grows autotrophically, heterotrophically, and mixotrophically on a variety of organic substrates. Glucose and serine promote a mixotrophic growth from which the yield is higher than the sum of autotrophic and heterotrophic yields, but serine assimilation requires light. The interaction of glucose and light was studied in proliferating and nonproliferating cells by respirometry (IRGA and Warburg) and growth experiments. Glucose inhibits the photosynthetic CO(2) fixation ten-fold and modifies the pigmentary system as it does in heterotrophic cultures. Light inhibits glucose uptake and assimilation, but under mixotrophic conditions maximal utilization of glucose is obtained. Mutants defective in autotrophic growth were isolated by mutagenesis with nitrosoguanidine. They show a degenerated pigmentary system and a mixotrophic growth yield equal to that of the heterotrophic growth. The analysis of the mixotrophic system shows that light energy, dissipated during autotrophic growth, is used under mixotrophic conditions. From the increase in growth, the increase in photosynthetic efficiency can be calculated as ca. sixfold.     

Influence of organic compounds and light limitation on the growth rate of estuarine benthic diatoms

Ten species of benthic diatoms from the Eems-Dollard estuary were grown in axenic cultures under various combinations of irradiance and supply of organic substrates. Six species were capable of growth in the dark on yeast extract, casamino acids, or glucose. Four of these species grew best in the presence of glucose, whereas the growth of the other two species was supported only by yeast extract and casamino acids. The light limited growth rate of only those species that were also capable of heterotrophic growth in the dark was increased by organic substrates. The rate of this “mixed” growth together with the absence of a lag-phase upon change from autotrophic to heterotrophic conditions indicates the nutritional versatility of these diatom species. A positive relation between the organic matter content of the natural habitat and the heterotrophic capacities of the diatom species is suggested. All species with heterotrophic capacities were isolated from muddy sediments, whereas two species isolated from a sandflat seem to be obligately autotrophic. Also two species from muddy sediments apparently had no heterotrophic capacities. The cells of the six species with heterotrophic capacities differed from those of the four species without such capacities in their higher surface to volume ratio.     

Autotrophic and Heterotrophic Metabolism of Hydrogenomonas I. Growth Yields and Patterns Under Dual Substrate Conditions

Auxotrophic mutants of Hydrogenomonas eutropha and H. facilis requiring utilizable amino acids were employed to demonstrate the simultaneous utilization of H(2) and an organic substrate for growth. The ratio of the cell yields under dual substrate conditions compared to heterotrophic conditions indicated the relative contributions of the autotrophic and heterotrophic systems to the growth of the organism. Wildtype H. eutropha grown under simultaneous conditions exhibited a dicyclic growth pattern, the first cycle representing either heterotrophic or simultaneous growth and the second cycle representing autotrophic growth. The duration of the changeover period was either very short with no plateau or long with a plateau up to 8 hr, depending upon the organic substrate. The growth rate under simultaneous conditions with some organic substrates was faster than either the autotrophic or heterotrophic rate, but was not the sum of the two rates. The data suggest that, in the presence of both organic and inorganic substrates, heterotrophic metabolism functions normally but autotrophic metabolism is partially repressed.     

Glycollate production and excretion byAlcaligenes eutrophus

Autotrophic cultures of the facultative chemolithotrophAlcaligenes eutrophus have been found to excrete glycollate. This excretion was greatly stimulated by the incorporation of up to 20% (v/v) oxygen in the hydrogen used for gassing. The stimulatory effect of oxygen was prevented by the addition of 10% (v/v) CO₂ to the gassing mixture. Glycollate excretion only in the presence of oxygen was increased by the addition of 2-pyridyl-hydroxymethane sulphonic acid (HPMS), an inhibitor of glycollate oxidation, indicating that glycollate formation itself was stimulated by oxygen. No glycollate excretion by cultures grown heterotrophically on pyruvate was detected, either in the absence or presence of HPMS, under heterotrophic or autotrophic conditions.Extracts from autotrophic cells showed phosphoglycollate phosphatase and glycollate oxidoreductase activities, which were considerably lower in extracts prepared from pyruvate- or fructose-grown (heterotrophic) cells. The increase in activity of both enzymes upon cell transfer from heterotrophic to autotrophic growth was prevented by chloramphenicol and resembled the induction ofd0ribulose 1,5-diphosphate carboxylase under the same conditions.Abbreviations DTE dithioerythritol - EDTA ethylenediamine tetraacetate - HPMS 2-pyridyl-hydroxymethane sulphonie acid - RuDP d-ribulose 1,5-diphosphate     

Investigation of mixotrophic,heterotrophic, and autotrophic growth of Chlorella vulgaris under agricultural waste medium

Growth of Chlorella vulgaris and its lipid production were investigated under autotrophic, heterotrophic, and mixotrophic conditions. Cheap agricultural waste molasses and corn steep liquor from industries were used as carbon and nitrogen sources, respectively. Chlorella vulgaris grew remarkably under this agricultural waste medium, which resulted in a reduction in the final cost of the biodiesel production. Maximum dry weight of 2.62 g L^?1 was obtained in mixotrophic growth with the highest lipid concentration of 0.86 g L^?1. These biomass and lipid concentrations were, respectively, 140% and 170% higher than autotrophic growth and 300% and 1200% higher than heterotrophic growth. In mixotrophic growth, independent or simultaneous occurrence of autotrophic and heterotrophic metabolisms was investigated. The growth of the microalgae was observed to take place first heterotrophically to a minimum substrate concentration with a little fraction in growth under autotrophic metabolism, and then the cells grew more autotrophically. It was found that mixotrophic growth was not a simple combination of heterotrophic and autotrophic growth.     

Mixotrophic Growth of Hydrogenomonas eutropha

Mixotrophic growth conditions were established by the addition of lactate to cultures of Hydrogenomonas eutropha growing autotrophically in a gaseous environment of H(2), O(2), and CO(2) (6:2:1). The specific growth rate of mixotrophic cultures was double that of the autotrophic cultures, and lactate disappearance paralleled growth. Growth yields in mixotrophic cultures were significantly greater than those in heterotrophic cultures for equal quantities of lactate consumed. The magnitude of the increase in yield was directly proportional to the absolute growth rate at the time of lactate addition to the starting autotrophic culture and to the time under mixotrophic conditions. The specific activities of hydrogenase and ribulose diphosphate carboxylase decreased during mixotrophic growth; the total activities increased somewhat. The results suggested that the complete autotrophic and heterotrophic physiologies functioned simultaneously under mixotrophic contions.     

Autotrophic and Heterotrophic Metabolism of Hydrogenomonas: Regulation of Autotrophic Growth by Organic Substrates

The effects of a number of organic substrates on the autotrophic metabolism of Hydrogenomonas eutropha were examined. Dual substrate (mixotrophic) cultivation in the presence of hydrogen plus either fructose or alanine allowed autotrophic growth to begin immediately after the exhaustion of the organic substrate. On the other hand, the presence of acetate, pyruvate, or glutamate caused a lengthy lag to occur before autotrophic growth commenced. With acetate or pyruvate this lag (plateau) in the dicyclic growth curve was due to the repression of ribulose diphosphate carboxylase (RDPC) synthesis during mixotrophic growth. During heterotrophic growth with glutamate, RDPC was partially repressed; however, during mixotrophic growth, RDPC activity was high. Thus the delay of autotrophic growth was not due to a repression of RDPC by glutamate. The data suggest that glutamate interferes with autotrophic metabolism by repressing the incorporation of inorganic nitrogen. The repression of these vital autotrophic functions by acetate, pyruvate, and glutamate occurred both in the presence and absence of hydrogen, i.e., during both heterotrophic and mixotrophic cultivation. The derepression of the affected systems during the plateau phase of the dicyclic growth curves was demonstrated. Carbon dioxide assimilation by whole cells agreed well with the RDPC activity of extracts from cells grown under similar conditions.     

Control of the glutathione S-transferase and mas1' promoter-driven GUS activity in auxin heterotrophic and autotrophic tobacco calli by exogenous 2,4-d-induced ethylene

Auxin autotrophic and heterotrophic lines of tobacco calli may differ not only in their indoleacetic acid (IAA) synthetizing abilities and sensitivities to exogenous auxins, but also in their gene expression patterns. Auxin autotrophic callus tissues from the leaf protoplasts of transgenic Nicotiana tabacum SR1 plants involving mas1′::GUS gene fusion were generated and the growth of cultures was compared with that of the heterotrophic lines of the same transgenic tissues on MS medium containing different concentrations of IAA or 2,4‐d . The mas1′::GUS gene fusion expression was investigated, together with the glutathione S‐transferase activities (GST, EC 2.5.1.18) in auxin autotrophic and heterotrophic tobacco calli. Both the mas1′ promoter and GST gene promoters contain ocs or ocs‐like elements, responsible for both auxin and ethylene/wound inducibility. The mas1′ promoter exhibited a much higher expression activity in the heterotrophic cultures growing on IAA than in the autotrophic ones, but in contrast with the natural auxin, the mas1′::GUS activity decreased at elevated 2,4‐d concentrations in the heterotrophic tissues and increased with increasing 2,4‐d concentrations in the autotrophic lines. The induction of GST activity by different exogenous auxin concentrations was much higher in the autotrophic lines, especially in the case of 2,4‐d . Higher concentrations of external 2,4‐d resulted in increased ethylene production, which displayed different kinetics in the two types of calli. The ethylene‐inducing 2,4‐d concentrations increased the growth of the heterotrophic, but decreased that of the autotrophic lines. Blocking the ethylene receptors and hence the signal perception by 2,5‐norbornadiene (NBD) in the heterotrophic tissues increased the 2,4‐d ‐induced mas1′ promoter and GST activities, suggesting that the gaseous hormone counteracted the auxin response pathway. This was not found in the autotrophic tissues, where NBD decreased the mas1′‐driven GUS activity. The GST activities were slightly decreased, or almost independent of the action of ethylene. It is suggested that the cross‐talk between the auxin‐ and ethylene‐induced signal transduction pathways may differ in the auxin autotrophic and heterotrophic lines.     

Auxin autotrophic tobacco callus tissues resist oxidative stress: the importance of glutathione S-transferase and glutathione peroxidase activities in auxin heterotrophic and autotrophic calli

Auxin autotrophic and heterotrophic tobacco callus lines were grown on MS medium with or without 100 mmol/L NaCl and growth and some of the stress-related activities, such as GPX, SOD, CAT, GST, GSH-PX, as well as the concentration of ethylene and H2O2, were measured and compared with each other. The auxin autotrophic calli grew slower, however, on the NaCl-containing medium the growth rate was higher than that of the heterotrophic cultures after two weeks of culturing. The stress-related ethylene production was lower in the autotrophic cultures and, contrary to the heterotrophic tissues, its level did not change significantly upon NaCl treatment. The guaiacol peroxidase (GPX) activities were higher in the autotrophic tissues in all cell fractions regardless of the presence of NaCl. Treated with NaCl, the GPX activities elevated in the soluble and covalently-bound fractions in the heterotrophic calli, but were not further increased in the autotrophic line. SOD and CAT activities were higher in the heterotrophic tissues, and were increased further by 100 mmol/L NaCl treatment. The GST and GSH-PX activities were higher in the autotrophic line, which might explain their enhanced stress tolerance. In the autotrophic tissues, the elevated antioxidant activities led to reduced levels of H2O2 and malondialdehyde; under mild NaCl stress, these levels decreased further. The lower growth rate and the effective protection against NaCl stress-induced oxidative damage of the autotrophic line can be explained by the cell wall-bound peroxidase and GSH-PX activities in the auxin autotrophic tissues. Their maintained growth rate indicates that the autotropic cultures were more resistant to exogenous H2O2.     

The importance of autotrophic versus heterotrophic oxidation of atmospheric ammonium in forest ecosystems with acid soil

Abstract The role of autotrophic and heterotrophic nitrifying microorganisms in the oxidation of atmospheric ammonium in two acid and one calcareous location of a Dutch woodland area was investigated. In soil slurries nitrate formation was completely inhibited by acetylene, a specific inhibitor of autotrophic ammonium-oxidizing bacteria. A survey of nitrifiers in the forest soils showed that both autotrophic ammonium- and nitrite-oxidizing bacteria were present in high numbers and evidence was obtained that autotrophic bacteria are able to nitrify below pH 4. These results show that autotrophic nitrifying bacteria may account for most of the nitrification in the examined soils. To assess the contribution of heterotrophic nitrifiers, about 200 strains of heterotrophic bacteria and 21 morphologically distinct fungal strains were isolated from the acid soil locations and tested for their ability to nitrify. Only one Penicillium strain produced nitrate in test media, but its nitrate formation when added to acid soils was poor. These findings indicate that in the investigated soil heterotrophs are of minor importance in the oxidation of atmospheric ammonium.     

EFFICIENCY OF GROWTH AND NUTRIENT UPTAKE FROM WASTEWATER BY HETEROTROPHIC,AUTOTROPHIC, AND MIXOTROPHIC CULTIVATION OF CHLORELLA VULGARIS IMMOBILIZED WITH AZOSPIRILLUM BRASILENSE1

Heterotrophic growth of microalgae presents significant economic advantages over the more common autotrophic cultivation. The efficiency of growth and nitrogen, phosphorus, and glucose uptake from synthetic wastewater was compared under heterotrophic, autotrophic, and mixotrophic regimes of Chlorella vulgaris Beij. immobilized in alginate beads, either alone or with the bacterium Azospirillum brasilense. Heterotrophic cultivation of C. vulgaris growing alone was superior to autotrophic cultivation. The added bacteria enhanced growth only under autotrophic and mixotrophic cultivations. Uptake of ammonium by the culture, yield of cells per ammonium unit, and total volumetric productivity of the culture were the highest under heterotrophic conditions when the microalga grew without the bacterium. Uptake of phosphate was higher under autotrophic conditions and similar under the other two regimes. Positive influence of the addition of A. brasilense was found only when light was supplied (autotrophic and mixotrophic), where affinity to phosphate and yield per phosphate unit were the highest under heterotrophic conditions. The pH of the culture was significantly reduced in all regimes where glucose was consumed, similarly in heterotrophic and mixotrophic cultures. It was concluded that the heterotrophic regime, using glucose, is superior to autotrophic and mixotrophic regimes for the uptake of ammonium and phosphate. Addition of A. brasilense positively affects the nutrient uptake only in the two regimes supplied with light.     

Reproductive success of the rotifer Brachionus calyciflorus feeding on ciliates and flagellates of different trophic modes

SUMMARY 1. The nutritional value of the bacterivorous ciliate Tetrahymena pyriformis and the algivorous ciliate Coleps sp., as well as the heterotrophic flagellate Chilomonas paramecium and the autotrophic flagellate Cryptomonas ovata , were investigated in population growth experiments using the rotifer B. calyciflorus . The two ciliates, both flagellates, which were of similar size, shape and mobility, were each offered as a sole diet and as a supplement to the alga Monoraphidium minutum , known to support reproduction of B. calyciflorus .
2. To further test nutritional differences between the prey organisms, prey selection experiments were conducted in which B. calyciflorus was able to select between the bacterivorous and algivorous ciliate, and between the heterotrophic and autotrophic flagellate.
3. The results demonstrated that both ciliates and the heterotrophic flagellate were not sufficient to support reproduction of B. calyciflorus when offered as a sole diet. They were, however, a good supplement to algal prey (except for the bacterivorous ciliate T. pyriformis ). In the prey selection experiments, B. calyciflorus positively selected for the algivorous Coleps sp. and the autotrophic C. ovata.
4. Overall, ciliates and heterotrophic flagellates may enhance survival of B. calyciflorus , but reproduction of the rotifer is likely to rely on algal prey. Both higher population growth of B. calyciflorus when fed the algivorous Coleps and the autotrophic Cryptomonas, along with their positive selection, give evidence for prey specific differences in nutrition, with algivorous or autotrophic prey species tending to be of higher nutritional value.     

Changes in the pelagic microbial food web due to artificial eutrophication

The effect of nutrient enrichment on the structure and carbon flow in the pelagic microbial food web was studied in mesocosm experiments using seawater from the northern Baltic Sea. The experiments included food webs of at least four trophic levels; (1) phytoplankton–bacteria, (2) flagellates, (3) ciliates and (4) mesozooplankton. In the enriched treatments high autotrophic growth rates were observed, followed by increased heterotrophic production. The largest growth increase was due to heterotrophic bacteria, indicating that the heterotrophic microbial food web was promoted. This was further supported by increased growth of heterotrophic flagellates and ciliates in the high nutrient treatments. The phytoplankton peak in the middle of the experiments was mainly due to an autotrophic nanoflagellate, Pyramimonas sp. At the end of the experiment, the proportion of heterotrophic organisms was higher in the nutrient enriched than in the nutrient-poor treatment, indicating increased predation control of primary producers. The proportion of potentially mixotrophic plankton, prymnesiophyceans, chrysophyceans and dinophyceans, were significantly higher in the nutrient-poor treatment. Furthermore, the results indicated that the food web efficiency, defined as mesozooplankton production per basal production (primary production + bacterial production − sedimentation), decreased with increasing nutrient status, possibly due to increasing loss processes in the food web. This could be explained by promotion of the heterotrophic microbial food web, causing more trophic levels and respiration steps in the food web.     

Mixotrophic and Autotrophic Growth of Thiobacillus acidophilus on Glucose and Thiosulfate

Mixotrophic growth of the facultatively autotrophic acidophile Thiobacillus acidophilus on mixtures of glucose and thiosulfate or tetrathionate was studied in substrate-limited chemostat cultures. Growth yields in mixotrophic cultures were higher than the sum of the heterotrophic and autotrophic growth yields. Pulse experiments with thiosulfate indicated that tetrathionate is an intermediate during thiosulfate oxidation by cell suspensions of T. acidophilus. From mixotrophic growth studies, the energetic value of thiosulfate and tetrathionate redox equivalents was estimated to be 50% of that of redox equivalents derived from glucose oxidation. Ribulose 1,5-bisphosphate carboxylase (RuBPCase) activities in cell extracts and rates of sulfur compound oxidation by cell suspensions increased with increasing thiosulfate/glucose ratios in the influent medium of the mixotrophic cultures. Significant RuBPCase and sulfur compound-oxidizing activities were detected in heterotrophically grown T. acidophilus. Polyhedral inclusion bodies (carboxysomes) could be observed at low frequencies in thin sections of cells grown in heterotrophic, glucose-limited chemostat cultures. Highest RuBPCase activities and carboxysome abundancy were observed in cells from autotrophic, CO₂-limited chemostat cultures. The maximum growth rate at which thiosulfate was still completely oxidized was increased when glucose was utilized simultaneously. This, together with the fact that even during heterotrophic growth the organism exhibited significant activities of enzymes involved in autotrophic metabolism, indicates that T. acidophilus is well adapted to a mixotrophic lifestyle. In this respect, T. acidophilus may have a competitive advantage over autotrophic acidophiles with respect to the sulfur compound oxidation in environments in which organic compounds are present.     

Depression of hydrogenase during limitation of electron donors and derepression of ribulosebisphosphate carboxylase during carbon limitation of Alcaligenes eutrophus

Alcaligenes eutrophus did not form the key enzymes of autotrophic metabolism, the soluble and particulate hydrogenases and ribulosebisphosphate carboxylase (RuBPC), during heterotrophic growth on succinate in batch cultures. During succinate-limited growth in a chemostat, high activities of both hydrogenases were observed. With decreasing dilution rate (D) the steady-state hydrogenase activity (H) followed first-order kinetics, expressed as follows: H = Hmax .e-alpha.D. An identical correlation was observed when autotrophic growth in a chemostat was limited by molecular hydrogen. During autotrophic growth under oxygen or carbon dioxide limitation, the activity if the soluble hydrogenase was low. These data suggested that hydrogenase formation depended on the availability of reducing equivalents to the cells. RuBPC activities were not correlated with the hydrogenase activities. During succinate-limited growth, RuBPC appeared at intermediate activities. During autotrophic growth in a carbon dioxide-limited chemostat, RuBPC was highly derepressed. RuBPC activity was not detected in cells that suffered from energy limitation with a surplus of carbon, as in a heterotrophic oxygen-limited chemostat, nor was it detected in cells limited in carbon and energy, as in the case of complete exhaustion of a heterotrophic substrate. From these data I concluded that RuBPC formation in A. eutrophus depends on two conditions, namely, carbon starvation and an excess of reducing equivalents.     

Theoretical predictions for how temperature affects the dynamics of interacting herbivores and plants

Concern about climate change has spurred experimental tests of how warming affects species' abundance and performance. As this body of research grows, interpretation and extrapolation to other species and systems have been limited by a lack of theory. To address the need for theory for how warming affects species interactions, we used consumer-prey models and the metabolic theory of ecology to develop quantitative predictions for how systematic differences between the temperature dependence of heterotrophic and autotrophic population growth lead to temperature-dependent herbivory. We found that herbivore and plant abundances change with temperature in proportion to the ratio of autotrophic to heterotrophic metabolic temperature dependences. This result is consistent across five different formulations of consumer-prey models and over varying resource supply rates. Two models predict that temperature-dependent herbivory causes primary producer abundance to be independent of temperature. This finding contradicts simpler extensions of metabolic theory to abundance that ignore trophic interactions, and is consistent with patterns in terrestrial ecosystems. When applied to experimental data, the model explained 77% and 66% of the variation in phytoplankton and zooplankton abundances, respectively. We suggest that metabolic theory provides a foundation for understanding the effects of temperature change on multitrophic ecological communities.     

Nutritional diversity of symbiotic ascidians in a Fijian seagrass meadow

In a coastal lagoon of Dravuni Island, Fiji, at least six species of compound ascidians, some of them harboringProchloron as symbiotic algae, were found in aSyringodium-dominated seagrass meadow. Based on their heterotrophic (filrer feeding rates) and autotrophic (photosynthetic) activities, carbon gain of the ascidians was categorized into two groups: (i) supported by heterotrophic metabolism; and (ii) supported by both heterotrophic and autotrophic metabolisms.Didemnum molle, Lissoclinum bistratum andLissolinum voeltzkowi belong to the latter group, and the relative contribution of the autotrophic process was a significant portion of their carbon gain (52–74%). These symbiotic ascidians were found in light microhabitats, while the heterotrophic species occupied shady environments rich in suspended organic materials, such as the sheath surface of the seagrass.     

Glycollate production and excretion by Alcaligenes eutrophus.

Autotrophic cultures of the facultative chemolithotroph Alcaligenes eutrophus have been found to excrete glycollate. This excretion was greatly stimulated by the incorporation of up to 20% (v/v) oxygen in the hydrogen used for gassing. The stimulatory effect of oxygen was prevented by the addition of 10% (v/v) CO2 to the gassing mixture. Glycollate excretion only in the presence of oxygen was increased by the addition of 2-pyridyl-hydroxymethane sulphonic acid (HPMS), an inhibitor of glycollate oxidation, indicating that glycollate formation itself was stimulated by oxygen. No glycollate excretion by cultures grown heterotrophically on pyruvate was detected, either in the absence or presence of HPMS, under heterotrophic or autotrophic cells showed phosphoglycollate phosphatase and glycollate oxidoreductase activities, which were considerably lower in extracts prepared from pyruvate- or fructose-grown (heterotrophic) cells. The increase in activity of both enzymes upon cell transfer from heterotrophic to autotrophic growth was prevented by chloramphenicol and resembled the induction of D-ribulose 1,5-diphosphate carboxylase under the same conditions.     

厌氧条件下小球藻细胞的异养转化和乳酸发酵(简报)

某些藻类植物,如小球藻——一种单细胞绿藻,不但能利用无机碳源通过光合作用进行自养生长,还能利用有机碳源转化为异养生长,这种转化又是可逆的。迄今为止,对于人工控制下藻细胞向异养转化的代谢和调控机理尚不清楚。本文通过分析小球藻细胞异养转化过程对氧气的依赖性,进一步研究它们在厌氧条件下的生长和乳酸发酵特征,探讨可异养转化的单细胞藻类(作为特殊的实验生物系统)在发酵工程和细胞工程领域里应用的可能性。     

Isolation, culture and characterization of a new strain of Euglena gracilis

A new strain of Euglena gracilis Klebs has been isolated from a highly polluted river; it was named MAT. Strain growth in different culture media was evaluated under heterotrophic and autotrophic conditions. Total lipid, sugar, protein and chlorophyll a production were studied. Results obtained for MAT were compared with data obtained for a UTEX Culture Collection strain. Likewise, cells from both strains were bleached using streptomycin, and grown in the same media used for green samples. Both MAT and UTEX showed clear differences in their biochemical composition and growth rate depending on the media used. They also exhibited different growth patterns. E. gracilis medium proved to be the best culture environment for both strains either in autotrophic or heterotrophic conditions. Results show that basal contents of lipids, sugars, proteins and chlorophyll a vary depending on the strain, and thus values obtained for one strain do not apply to another. Moreover, strain origin may have an influence on the mechanisms of adaptation or defense developed by each sample.