Open AccessCharacterization of Azotobacter vinelandii aggregation in submerged culture by digital image analysis
Author(s) -
Peña Carlos,
Reyes César,
LarraldeCorona Patricia,
Corkidi Gabriel,
Galindo Enrique
Publication year - 2002
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.1574-6968.2002.tb11047.x
Subject(s) - azotobacter vinelandii , laboratory flask , aeration , dilution , chemistry , mixing (physics) , azotobacter , chromatography , methylene blue , digital image analysis , biophysics , biological system , bacteria , biology , biochemistry , organic chemistry , nitrogenase , physics , genetics , quantum mechanics , nitrogen fixation , photocatalysis , computer science , nitrogen , computer vision , thermodynamics , catalysis
A simple and accurate method for determining the distribution of sizes of single cells and aggregates of Azotobacter vinelandii by image analysis has been developed. A staining procedure using methylene blue helps to enhance the contrast between aggregates and background without altering aggregate size distribution. Sample dilution affected the distribution of the population and therefore should be avoided. Mixing and aeration conditions during culture play an important role in the aggregation of A. vinelandii . Cells grown under mild mixing conditions (unbaffled flasks) presented a thick slime layer and formed aggregates of up to 35 μm of average equivalent diameter. In contrast, under strong agitation conditions (baffled flasks) practically no aggregates were formed throughout cultivation. The method described can be used for the characterization of aggregation of other microbial cultures.