Open AccessInduction of increase in the heterocyst frequency of Anabaena sp. strain ATCC33047. Effect on ammonium photoproduction
Author(s) -
Ramos Juan L.,
Madueño Francisco
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01669.x
Subject(s) - heterocyst , nitrogenase , ammonium , molybdate , nitrogen fixation , strain (injury) , biology , nitrogen , ammonium molybdate , anabaena , biophysics , cyanobacteria , biochemistry , chemistry , inorganic chemistry , bacteria , anatomy , genetics , fertilizer , organic chemistry , agronomy
Several approaches have been followed to increase the nitrogenase level in filaments of Anabaena ATCC33047. In a nitrogen‐free medium lacking added molybdate and supplemented with 10 mM tungstate, growth was impaired as a result of decreased nitrogenase activity level. Under these conditions, the filaments exhibited nitrogen starvation symptoms and a high heterocyst frequency, with heterocysts being up to 28% of the total number of cells in the filaments, while a regular pattern of heterocyst distribution was maintained. Normal nitrogenase level and nitrogen status were recovered upon molybdate addition, with resumption of growth and decrease of the heterocyst frequency with time until reaching a value of about 10%. The yield of ammonium photoproduction from N 2 by filaments displaying different heterocyst frequencies and treated with l ‐methionine‐ d,l ‐sulfoximine (MSX) was determined. Maximal rates were obtained with filaments containing 16% of the cells differentiated as heterocysts. Results indicate that appropriate manipulation of the heterocyst frequency leads to an improvement in the efficiency of conversion of light energy into chemical energy through photoreduction of N 2 to ammonium.