Effect of heavy metals on nitrate assimilation in the eukaryotic microalga Chlamydomonas reinhardtii

Devriese, Maartje; Tsakaloudi, V.; Garbayo, Inés; Léon, Rosa; Vílchez, Carlos; Vigara, Javier

doi:10.1016/s0981-9428(01)01257-8

Cited by 51 publications

(34 citation statements)

References 20 publications

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“…Cell pellets were washed twice with 0.1 M Tris-HCl buffer (pH 8) and resuspended, and then were permeabilized by adding 50 ll toluene and shaking vigorously for 30 s. NiR activity was determined in 1 ml reaction mixture containing: 50 lmol Tris-HCl (pH 8), 30 lmol KNO 2 , 10 lmol methylviologen and 0.2 ml permeabilized cell suspension. The reaction was started by the addition of 30 lmol sodium dithionite freshly dissolved in 0.3 M NaHCO 3 solution (Devriese et al 2001). After 10 min incubation at 40°C, the reaction was stopped by vigorous shaking and the nitrite formed was determined as described above.…”

Section: Measurement Of Nitrite Reductase Activitymentioning

confidence: 99%

Nitrite utilization by Chaetoceros muelleri under elevated CO2 concentration

2007

World J Microbiol Biotechnol

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Chaetoceros muelleri (Lemn.) was cultured with nitrite (NO 2 -) or nitrate (NO 3 -) as the sole nitrogen source and aerated with air or with CO 2 -enriched air. Cells of C. muelleri excreted into the medium nitrite produced by reduction of nitrate when grown with 100 lM NaNO 3 as nitrogen source. Accordingly, NO 2 -concentration reached 10.4 lM after 95 h at the low CO 2 condition (aerated with air); while the maximum NO 2 -concentration was only around 2.0 lM at the high CO 2 condition (aerated with 5% CO 2 in air), furthermore, after 30 h it decreased to no more than 1.0 lM. NO 2 -was almost assimilated in 80 h when C. muelleri was cultured at the high CO 2 condition with 100 lM NaNO 2 as sole nitrogen source. At the high CO 2 condition, after 3 h the activity of nitrite reductase was as much as 50% higher than that at the low CO 2 condition. It was indicated that enriched CO 2 concentration could inhibit nitrite excretion and enhance nitrite assimilation by cells. Therefore, aeration with enriched CO 2 might be an effective way to control nitrite content in aquaculture systems.

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Section: Measurement Of Nitrite Reductase Activitymentioning

confidence: 99%

Nitrite utilization by Chaetoceros muelleri under elevated CO2 concentration

2007

World J Microbiol Biotechnol

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“…Singh & Yadav (1984) showed that Cd inhibited the uptake of phosphorus by phytoplankton. Awasthi & Rai (2005) examined the effects of Cd on nitrate uptake by Scenedesmus quadricauda and showed a 45% reduction in nitrate uptake in the presence of 2.3 Â 10 À6 M Cd, which corresponded to the LC 50 concentration; Devriese et al (2001) showed 75% inhibition of nitrate uptake in Chlamydomonas reinhardtii at concentrations exceeding 1.5 Â 10 À4 M, but no effect was observed below 10 À4 M Cd ions. Because both nitrogen and Cd are known to affect lipid synthesis, and Cd ions induce oxidative stress in microalgae (Pinto et al, 2003), different metabolic routes are likely to be affected with such combinations.…”

Section: Introductionmentioning

confidence: 99%

Effects of cadmium and nitrogen on lipid composition of Chlorella vulgaris (Trebouxiophyceae, Chlorophyta)

Chia

Lombardi

Melão

et al. 2013

European Journal of Phycology

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Investigations were carried out to evaluate lipid class and fatty acid composition of Chlorella vulgaris in relation to several combinations of cadmium (2 Â 10 -8 ; 10 À7 M Cd) and nitrogen (2.9 Â 10 À6 to 1.1 Â 10 À3 M N) concentrations. Triacylglycerols (TAG), acetone mobile polar lipids (AMPL) and phospholipids (PL) were the major lipid classes of C. vulgaris under all the tested conditions. TAG was the lipid class accumulated in the highest amount in N-limited C. vulgaris. The AMPL lipid class was lowest at the lowest N and highest Cd treatment. High proportions of saturated fatty acids (SAFA) and monounsaturated fatty acids (MUFA) in the total lipid extracts were recorded under N limitation in the presence of Cd. 16:1(n-11) was an exception among the MUFA as its levels decreased at low N. Total polyunsaturated FA (PUFA), !3 PUFA levels, and PUFA:SAFA ratios increased with increasing N concentrations, but when exposed to Cd, their levels were significantly reduced. Unlike the other PUFA, 18:2(n-6) increased with increasing N limitation. Significant negative relationships between TAG, MUFA and SAFA with N were recorded. Cd had a positive correlation with TAG, while N was with AMPL, PL and PUFA. In conclusion, a combination of N limitation and Cd stress significantly altered the lipid composition of C. vulgaris, and N limitation had the most significant overall effect on lipid class and fatty acid composition of the microalga.

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“…Moreover, such metal ions are important for other plant processes, e.g. Mn 2+ influences nitrogen assimilation through regulating the activity of glutamine synthase (Devriese et al, 2001) while Fe is important for optimal activities of the photosynthetic electron transfer chain (Kudo et al, 2000;Davey & Geider, 2001) and nitrate reductase (Kudo et al, 2000), and in improving the chlorophyll a: carotenoid ratio (Li et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

Effect of Seagrass Cover and Mineral Content on <i>Kappaphycus</i> and <i>Eucheuma</i> Productivity in Zanzibar

Mtolera

2004

West Ind. Oc. J Mar. Sci.

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Abstract-The productivity of two species of red algae, namely Eucheuma denticulatum (Burman) Collins et Harvey and Kappaphycus alvarezii (Doty) Doty was investigated at Paje and Uroa, two sites in Zanzibar differing in seagrass cover. The growth rate (GR) of E. denticulatum in Paje (low seagrass cover) was 20-75% lower than in Uroa (high seagrass cover), depending on season. Growth of K. alvarezii in Paje was compromised by Polysiphonia spp. epiphytism. Manganese, iron, copper and zinc contents of both E. denticulatum and K. alvarezii from Paje were 35-99% lower than in E. denticulatum from Uroa. Culturing of epiphyte-infested or healthy K. alvarezii in seawater fortified with the mentioned minerals improved daily GR by 10-200 %. The effect of Cu, Zn and Mn in K. alvarezii with epiphytic infestation and 'ice-ice' was positive only when Provasoli solution was added. The GR of E. denticulatum was virtually unchanged by the addition of minerals. It is suggested that Fe, Zn, and especially Mn may play an important role in conferring resistance to physical stress to the macroalgae, stress which eventually makes them more susceptible to epiphytism and/or a bacterial infection that is responsible for a disease condition known as 'ice-ice'. Ice-ice describes the texture and colour of the affected thalli. The possible role of seagrasses to the productivity of algae is also discussed.

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Effect of heavy metals on nitrate assimilation in the eukaryotic microalga Chlamydomonas reinhardtii

Cited by 51 publications

References 20 publications

Nitrite utilization by Chaetoceros muelleri under elevated CO2 concentration

Nitrite utilization by Chaetoceros muelleri under elevated CO2 concentration

Effects of cadmium and nitrogen on lipid composition of Chlorella vulgaris (Trebouxiophyceae, Chlorophyta)

Effect of Seagrass Cover and Mineral Content on <i>Kappaphycus</i> and <i>Eucheuma</i> Productivity in Zanzibar

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