Surge ammonium uptake in macroalgae from a coral atoll

Raikar, Varsha; Wafar, M.V.M.

doi:10.1016/j.jembe.2006.08.002

Cited by 10 publications

(4 citation statements)

References 33 publications

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“…By contrast, the ammonium uptake rates of three seaweed species ( Ulva lactuca , Soliera robusta and Dictyota dichotoma ) showed no diurnal variation, i.e . the rates of ammonium uptake in the light were similar to the rates in the dark (Raikar & Wafar ). Surprisingly, the uptake of inorganic nitrogen in light versus darkness by seagrasses has been assessed only twice, for Zostera marina and Thalassia testudinum (Iizumi & Hattori ; Lee & Dunton ).…”

Section: Introductionsupporting

confidence: 72%

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Nitrogen uptake in light versus darkness of the seagrass Zostera noltei: integration with carbon metabolism

2016

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We conducted a study that shows that light and dark conditions do not affect the uptake rates of ammonium and nitrate by the seagrass Zostera noltei. This is an important advantage over some seaweed species in which these rates are severely reduced at night. In the light, the ammonium uptake rates were initially higher (15 and 20 lmolÁg À1 Áh À1 ) and stabilized at a rate of 5 lmolÁg À1 Áh À1 after 1 h, whereas in the dark the rates remained constant at a rate of 10 lmolÁg À1 Áh À1 over the first 180 min of incubation. The rates of nitrate uptake in the light were high within the first 120 min of incubation (7.2-11.1 lmolÁg À1 Áh À1 ) and decreased afterwards to lower values (0.8-3.9 lmolÁg À1 Áh À1 ), whereas in the dark the rates fluctuated around 0.0-11.1 lmolÁg À1 Áh À1 throughout the whole incubation time (7 h). The soluble sugar content of Z. noltei leaves increased significantly with both ammonium and nitrate incubations in the light, indicating the metabolic outcome of photosynthesis. In the dark, there was no significant variation in either the soluble sugar or in the starch content of leaves, rhizomes or roots in either the ammonium or nitrate incubations. However, the total starch content of plants decreased at night whereas the total soluble sugars increased, suggesting a process of starch catabolism to generate energy with the consequent production of smaller monosaccharide products. The starch content of rhizomes decreased significantly during the light incubations with nitrate but not with ammonium. These results suggest that carbohydrate mobilization is necessary for Z. noltei to account for extra energetic costs needed for the uptake and assimilation of nitrate. Furthermore, our results suggest that nitrate uptake, at least during the day, requires the mobilization of starch whereas the uptake of ammonium does not.

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Section: Introductionsupporting

confidence: 72%

“…This has been shown both for phytoplankton and seaweed species (Conway et al . ; Thomas & Harrison ; Pedersen ; Dy & Yap ; Raikar & Wafar ). Initial rapid accumulation of ammonium by the leaves of the seagrass Zostera marina has also been reported (Short & McRoy ).…”

Section: Discussionmentioning

confidence: 99%

Nitrogen uptake in light versus darkness of the seagrass Zostera noltei: integration with carbon metabolism

2016

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“…Glenn and Doty (1990) suggested that the absorption of nutrients during the fast flowing water among the plant canopy is higher for ammonium at a lower depth than for nitrate at the higher depth. The absorption of ammonium by seaweed is more important than nitrate (Dy and Yap, 2001;Raikar and Wafar, 2006). Similarly to DGR of K. alvarezii in first study, the second study with brown strain showed the interaction between strain and initial weight at the same depth which was highly significant (P<0.01).…”

Section: Daily Growth Ratementioning

confidence: 78%

Growth and Carrageenan from Kappaphycus alvarezii (Doty) at Different Depths and Their Possible Application in Other Locations

Wenno

Syamsuddin

Jamal

2016

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This study aimed to evaluate the growth and yield of carrageenan from Kappaphycus alvarezii (Doty) cultured at different depths of water. The study lasted for 49 days, using two strains (green and brown), three initial weights (50, 100, 150 g), and five levels of depth (1, 2½, 4, 5½, 7 m). The results showed significant differences between growth rate and yield of carrageenan on the three treatments (P<0.01). The highest growth rate of both morphology types of green and brown occur on the same weight and depth i.e., at initial weight 100 g and depth 2½ m, respectively at 5.68 and 6.05%/day. The yield of carrageenan is likely to increase in depth with the highest value at a depth of 7 m, respectively 17.12% at green type and 14.63% at brown type. The results showed that reducing growth may increase the yield of carrageenan by the increasing of water depth. Based on these results, this study can be applied to another location as long as the quality of water allows farming activities.

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“…Glenn dan Doty (1990) mengemukakan bahwa penyerapan unsur hara saat air mengalir cepat di antara tallus lebih tinggi untuk amonium pada kedalaman rendah daripada untuk nitrat pada kedalaman yang tinggi. Penyerapan amonium oleh rumput laut lebih penting daripada penyerapan nitrat (Dy dan Yap, 2001;Raikar dan Wafar, 2006). Gambar 2 memperlihatkan laju pertumbuhan harian strain coklat yang lebih tinggi daripada strain hijau.…”

Section: Hasil Dan Pembahasanunclassified

BEBERAPA PARAMETER KIMIA YANG MEMPENGARUHI PERTUMBUHAN RUMPUT LAUT MERAH Kappaphycus alvarezii (DOTY) DI PERAIRAN LEBIH-DALAM

2014

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Abstrak : Secara konvesional, budi daya rumput laut memerlukan wilayah besar pada perairan dangkal, tetapi tidak semua air cocok untuk pembiakannya. Penelitian ini bertujuan untuk menguji pengaruh beberapa parameter kimia yang cocok untuk tumbuhnya ganggang merah Kappaphycus alvarezii di perairan laut dalam. Penelitian ini difasilitasi dengan beberapa rakit gantung yang ditempatkan secara diagonal, satu di bawah yang lain, pada kedalaman 100, 250, 400, 550 dan 700 cm. Pemotongan tunas dari strain hijau dan coklat digunakan sebagai bibit awal dengan berat 50, 100 dan 150 g. Semua tunas diikat pada tali nilon dengan diameter 1 mm yang sudah diatur pada tali dengan diameter 5 mm yang kemudian akan ditempatkan horizontal pada rakit gantung. Ruang antara dua tali panjang dan dua rumpun rumput laut diatur pada jarak 25 cm. Hasil penelitian menunjukkan bahwa sebagian besar dari laju pertumbuhan harian berkurang dengan meningkatnya kedalaman air. Rata-rata tertinggi dari laju pertumbuhan harian (DGR) dari kedua strain pada berat 100 g yaitu 5,28 ± 0,24% untuk hijau dan 5,45 ± 0,18% untuk cokelat. Analisis varians (ANOVA) dari DGR menunjukkan interaksi antara strain dan berat awal, antara strain dan kedalaman, dan antara berat awal dan kedalaman yang signifikan (P <0,01), namun antara strain, berat awal dan kedalaman tidak ada yang signifikan (P> 0,05). Zat kimia yang berhubungan dengan DGR berdasarkan analisis regresi multivariat yaitu salinitas, pH, amonium dan magnesium

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Surge ammonium uptake in macroalgae from a coral atoll

Cited by 10 publications

References 33 publications

Nitrogen uptake in light versus darkness of the seagrass Zostera noltei: integration with carbon metabolism

Nitrogen uptake in light versus darkness of the seagrass Zostera noltei: integration with carbon metabolism

Growth and Carrageenan from Kappaphycus alvarezii (Doty) at Different Depths and Their Possible Application in Other Locations

BEBERAPA PARAMETER KIMIA YANG MEMPENGARUHI PERTUMBUHAN RUMPUT LAUT MERAH Kappaphycus alvarezii (DOTY) DI PERAIRAN LEBIH-DALAM

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