Open AccessAlgal growth enhancement by bacteria: Is consumption of photosynthetic oxygen involved?
Author(s) -
Mouget JeanLuc,
Dakhama Azzeddine,
Lavoie Marc C.,
Noüe Joël
Publication year - 1995
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.1995.tb00159.x
Subject(s) - photosynthesis , biology , chlorella , oxygen , oxygen tension , bacterial growth , bacteria , algae , chlorella vulgaris , scenedesmus , botany , chemistry , genetics , organic chemistry
Pseudomonas diminuta and P. vesicularis , two obligate aerobes isolated from laboratory algal cultures, stimulated the growth of the green microalgae Scenedesmus bicellularis and Chlorella sp., without releasing any growth promoting substance. An intimate contact between both microorganisms was necessary for significant algal growth enhancement. The possibility of algal growth stimulation by bacterial attenuation of photosynthetic oxygen tension was indirectly examined by simulating the effect of bacteria through a physical removal of oxygen (air suction). Vacuum‐treated cultures showed an increase in growth rate and photosynthetic activity as compared to the control, a result which cannot be explained by differences in CO 2 /HCO 3 − pump activity. In the presence of P. diminuta , the photosynthetic activity of S. bicellularis was more strongly stimulated under a limited concentration of inorganic carbon. It is suggested that, apart from a CO 2 supply, aerobic bacteria can promote algal growth by reducing the photosynthetic oxygen tension within the microenvironment of the algal cells, thereby creating more favorable conditions for optimal photosynthetic algal growth.