Polynucleobacter necessarius Heckmann and Schmidt 1987 emend. Hahn et al. 2016 Polynucleobacter necessarius necessarius (Heckmann and Schmidt 1987) Hahn et al. 2009 Hahn M.W. Schmidt J. Pitt A. Taipale S.J. Lang E. Reclassification of four Polynucleobacter necessarius strains as Polynucleobacter asymbioticus comb. nov., Polynucleobacter duraquae sp. nov., Polynucleobacter yangtzensis sp. nov., and Polynucleobacter sinensis sp. nov., and emended description of the species Polynucleobacter necessarius 2016 66 8 2883 2892 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijsem.0.001073 27064460 Springer N. Amann R. Ludwig W. Schleifer K.H. Schmidt H. Polynucleobacter necessarius, an obligate bacterial endosymbiont of the hypotrichous ciliate Euplotes aediculatus, is a member of the beta-subclass of Proteobacteria 1996 135 333 336 FEMS Microbiology Letters FEMS Microbiol Lett 0378-1097 1574-6968 8595875 Vannini C. Pockl M. Petroni G. Wu Q.L. Lang E. Stackebrandt E. Schrallhammer M. Richardson P.M. Hahn M.W. Endosymbiosis in statu nascendi: close phylogenetic relationship between obligately endosymbiotic and obligately free-living Polynucleobacter strains (Betaproteobacteria) 2007 9 347 359 Environmental Microbiology Environ Microbiol 1462-2912 1462-2920 10.1111/j.1462-2920.2006.01144.x 17222133 Hahn M.W. Lang E. Brandt U. Wu Q.L. Scheuerl T. Emended description of the genus Polynucleobacter and the species Polynucleobacter necessarius and proposal of two subspecies, P. necessarius subsp. necessarius subsp. nov. and P. necessarius subsp. asymbioticus subsp. nov. 2009 59 8 2002 2009 International Journal of Systematic and Evolutionary Microbiology Int J Syst Evol Microbiol 1466-5026 1466-5034 10.1099/ijs.0.005801-0 19567561 Heckmann K. Schmidt H.J. Polynucleobacter necessarius gen. nov., sp. nov., an obligately endosymbiontic bacterium living in the cytoplasm of Euplotes aediculatus. 1987 37 4 456 457 International Journal of Systematic Bacteriology Int J Syst Bacteriol 0020-7713 10.1099/00207713-37-4-456 The strain harboured by E. aediculatus str. ATCC 30859 differed in four positions from the previously determined sequence, X93019. The strain was also available from the Heckmann culture collection, University of Munster, Germany.