Proceedings of the 1986 International Congress on Renewable Energy Sources. Ammonia photoproduction by immobilized Azolla Caroliniana. International Congress on Renewable Energy Sources [18-23 Mayo 1986, Madrid].

Consejo Superior de Investigaciones Científicas.
Terol, S., ed. Vincenzini, M. ... [et al.].

1987

V.1
1113
CIENA

84-00-6673-1

The photosynthetic N2-fixing symbiosis between the water fern Azolla and the cyanobacterium Anabaena was essayed to verify the potential of the system as photobiological producer of extracellular ammonia from water and N2. The photoproduction of ammonia was induced by treating Azolla with the glutamine synthetase innibitor L-methionine-DL-sulfoximine (MSX). Free and agar-entrapped fronds of Azolla caroliniana were tested and the amount of ammonia released was compared to the nitrogen fixing capacity of a growing culture (control) kept under the same experimental conditions except that MSX treatment was omitted. The experiments were run outdoor under natural conditions of temperature and light intensity. Agar-entrapped, MXS-treated Azolla fronds retained their NH4+- producing activity longer than the free ones. Their daily rate of ammonia photoproduction was 8.1 mg NH + (g dry weight)-1. This value represented over 60. ABSTRACT. of the nitrogen fixing capacity of the control. About 30. INTRODUCTION. of the ammonia produced was released during the night. The NH4+- producing activity of the agar-entrapped Azolla caroliniana lasted nine days; afterwards ammonia production ceased owing to the complete degradation of the Azolla pigments induced by the MSX-dependent nitrogen starvation. These deleterious effects of the inhibitor seem to be not reversible in Azolla and may be alleviated only by avoiding a complete inhibition of glutamine synthetase. This was accomplished by a lighter treatment of Azolla with MSX but in this case, desides a lower ammonia production, growth was also observed. MATERIALS AND METHODS. RESULTS AND DISCUSSION. REFERENCES.

Presenta ilus., tbls. y gráfs.

GENERAL; BIOMASA; AMONIACO; FOTOPRODUCCION; ENERGIA SOLAR; CONVERSION DE LA ENERGIA; EXPERIMENTOS;