SIMULTANEOUS PHOTOPRODUCTION OF HYDROGEN AND AMMONIA BY A NON-HETEROCYSTOUS CYANOBACTERIUM PLECTONEMA BORYANUM

[摘要] Filamentous, non-heterocystous diazotrophic cyanobacterium Plectonema boryanum simultaneously photoproduced hydrogen (0.30μmol mg-1 dry wth-1) and ammonium (8.2nmol mg-1 dry wth-1) under microaerobic (A:CO2, 96:4, v/v) conditions in the presence of 1mM sulfide. Nitrogen in the gas phase (A:CO2:N2, 72:4:24, v/v) enhanced the process more than two fold. A glutamine synthetase inhibitor, MSX, stimulated ammonium excretion and H2-production and pulses of MSX rather than a single dose favoured both the processes. A higher dose (15μM) in comparison to lower dose (5μM) of MSX, although it stimulated H2-evolution and NH4+-excretion, shortened the duration of both the processes. The stability of both the processes was prolonged in alginate-immobilized cyanobacterial cells besides enhancement in H2-evolution and NH4+-excretion. MSX was less toxic under immobilized state than the free cells.

[学科分类] 微生物学和免疫学