TY - JOUR
T1 - [68] Cultures of Azospirillum
AU - Albrecht, S. L.
AU - Okon, Y.
PY - 1980/1/1
Y1 - 1980/1/1
N2 - This chapter discusses the studies focusing on cultures of Spirillum lipoferum (Azospirillum). The recent isolation of the N2-fixing bacterium Azospirillum has initiated numerous investigations of this organism. Azospirillum can fix N2 either as a free-living organism or in association with plant roots. This chapter illustrates various applications for Azospirillum cultures and the growth conditions recommended for each specific case. Cells to be used as inoculum in the laboratory or field can be grown under aerobic conditions in NH4Cl-supplemented media or under nitrogen-limiting conditions, respectively. These convenient conditions give the fastest growth rate. Cultures of this type are also useful for producing cells for cytochrome investigations, enzyme extractions, or physiological studies. Growth under microaerophilic conditions on an N‑free semisolid agar is suggested for the isolation of the organism and for studying the substrates and growth conditions for N2 fixation. This method may also be used to prepare small quantities of N2-fixing cells. The cells can be centrifuged down to a pellet and the semisolid agar easily decanted. It is possible to provide large quantities of N2-fixing cells for studies of cell-free nitrogenase when the organism is grown in liquid culture, with N2 as the sole nitrogen source and at a constant optimal pO2.
AB - This chapter discusses the studies focusing on cultures of Spirillum lipoferum (Azospirillum). The recent isolation of the N2-fixing bacterium Azospirillum has initiated numerous investigations of this organism. Azospirillum can fix N2 either as a free-living organism or in association with plant roots. This chapter illustrates various applications for Azospirillum cultures and the growth conditions recommended for each specific case. Cells to be used as inoculum in the laboratory or field can be grown under aerobic conditions in NH4Cl-supplemented media or under nitrogen-limiting conditions, respectively. These convenient conditions give the fastest growth rate. Cultures of this type are also useful for producing cells for cytochrome investigations, enzyme extractions, or physiological studies. Growth under microaerophilic conditions on an N‑free semisolid agar is suggested for the isolation of the organism and for studying the substrates and growth conditions for N2 fixation. This method may also be used to prepare small quantities of N2-fixing cells. The cells can be centrifuged down to a pellet and the semisolid agar easily decanted. It is possible to provide large quantities of N2-fixing cells for studies of cell-free nitrogenase when the organism is grown in liquid culture, with N2 as the sole nitrogen source and at a constant optimal pO2.
UR - http://www.scopus.com/inward/record.url?scp=77957005938&partnerID=8YFLogxK
U2 - 10.1016/S0076-6879(80)69070-3
DO - 10.1016/S0076-6879(80)69070-3
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AN - SCOPUS:77957005938
SN - 0076-6879
VL - 69
SP - 739
EP - 749
JO - Methods in Enzymology
JF - Methods in Enzymology
IS - C
ER -