[New filamentous photosynthesizing green bacteria with gas vacuoles]

The plankton of the stratified Karelian lakes was found to contain new large filamentous photosynthetic green bacteria with gas vacuoles; their vertical distribution in the lakes was studied, and also the ultrathin structure, the type of pigment (bacteriochlorophyll d), and the physiology. The bacteria have been classified as a new genus Chloronema nov. gen. within the family Chloroflexaceae, with two new species C. spiroideum nov. sp. and C. giganteum nov. sp.