The excretion of organic nitrogen by marine algae in batch and continuous culture

1972 ◽  
Vol 50 (12) ◽  
pp. 2605-2611 ◽  
Author(s):  
B. S. Newell ◽  
G. Dalpont ◽  
B. R. Grant
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Continuous Culture ◽  
Organic Material ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Marine Algae ◽  
Algal Species ◽  
Continuous Cultures

Production of varying amounts of dissolved organic nitrogen has been demonstrated in cultures of eight species of marine algae. The material appears to be polypeptide. Continuous culture experiments with two algal species showed that production of this organic material was not increased by stress in the form of changes in growth rate, light, carbon dioxide, or pH. It was increased when the continuous cultures were allowed to stagnate.

Effect of carbon dioxide on growth of Pseudomonas putida ATCC 11172 on asparagine, citrate, glucose, and lactate in batch and continuous culture

1985 ◽  
Vol 31 (9) ◽  
pp. 763-766 ◽  
Author(s):  
Göran Molin
Keyword(s):  
Carbon Dioxide ◽  
Growth Rate ◽  
Pseudomonas Putida ◽  
Continuous Culture ◽  
Specific Growth ◽  
Carbon Sources ◽  
Maximum Specific Growth Rate ◽  
The Other ◽  
Continuous Cultures ◽  
Batch Cultures

The growth of Pseudomonas putida ATCC 11172 on L-asparagine, citrate, D-glucose, and L-lactate was followed in air and in 40% CO2 + air, using batch and carbon-limited continuous cultures. Batch cultures in air utilized a mixture of the carbon sources simultaneously. However, a change to 40% CO2 favoured the utilization of glucose. The maximum specific growth rate (μmax) in air was about 0.3 h−1 on glucose and 0.6 h−1 on the other carbon sources. In CO2, the μmax for glucose was reduced by 16% compared with almost 60–70% for the others. An order of preference for the different carbon sources in continuous cultures was determined by comparing the dilution rates at which the different carbon sources started to appear in the effluent. Glucose was the first compound to appear as the dilution rate increased (lowest preference when grown in air). In 40% CO2, the μmax for glucose was slightly higher than the others and the recorded preference for glucose in continuous culture was equal to that for citrate but was somewhat lower than that of lactate and asparagine. D-Gluconate and glucono-δ-lactone were produced as a step in the utilization of glucose. The D-gluconate production was enhanced by CO2.

Growth response of four freshwater algal species to dissolved organic nitrogen of different concentration and complexity

2015 ◽  
Vol 60 (8) ◽  
pp. 1613-1621 ◽  
Author(s):  
Dorothea Fiedler ◽  
Daniel Graeber ◽  
Maria Badrian ◽  
Jan Köhler
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Growth Response ◽  
Algal Species

Anaerobic Semi-Continuous Culture Biodegradation of Dichlorophenols Containing an Ortho Chlorine

1987 ◽  
Vol 22 (3) ◽  
pp. 427-436 ◽  
Author(s):  
S.E. Hrudey ◽  
E. Knettig ◽  
P.M. Fedorak ◽  
S.A. Daignault
Keyword(s):  
Activated Carbon ◽  
Continuous Culture ◽  
Chlorine Atom ◽  
Degradation Process ◽  
Anaerobic Sludge ◽  
Continuous Cultures ◽  
Complete Mineralization

Abstract Rapid and preferential dechlorination of the ortho chlorine from 2,6-, 2,4- and 2,3- dichlorophenol substrates was observed in semi-continuous cultures inoculated with 50% unacclimated anaerobic sludge. The rate of further dechlorination depended on the position of the second chlorine atom. The dechlorination rates for the second chlorine ranked ortho > para > meta. Complete mineralization to methane was only observed in cultures fed 2,6-dichlorophenol. Addition of activated carbon to the anaerobic cultures showed some benefit to the degradation process.

Electro-Oxidation to Convert Dissolved Organic Nitrogen and Soluble Non-Reactive Phosphorus to More Readily Removable and Recoverable Forms

Chemosphere ◽  
2021 ◽  
pp. 130876
Author(s):  
Synthia P. Mallick ◽  
Donald R. Ryan ◽  
Kaushik Venkiteshwaran ◽  
Patrick J. McNamara ◽  
Brooke K. Mayer
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Electro Oxidation ◽  
Reactive Phosphorus

scholarly journals Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation

2013 ◽  
Vol 10 (11) ◽  
pp. 7609-7622 ◽  
Author(s):  
M. Alkhatib ◽  
P. A. del Giorgio ◽  
Y. Gelinas ◽  
M. F. Lehmann
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Bottom Water ◽  
Estuarine Sediments ◽  
Internal Source ◽  
Lawrence Estuary ◽  
Element Partitioning ◽  
Sediment Porewaters ◽  
St Lawrence Estuary

Abstract. The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m−2 d−1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m−2 d−1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5–6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

Sign in / Sign up

Export Citation Format

Share Document