ectothiorhodospiraceae ectothiorhodospiraceae the ectothiorhodospiraceae are a family of purple sulfur bacteria, distinguished by producing sulfur globules outside of their cells. the cells are rod-shaped, vibrioid, or spirilla, and they are able to move using flagella. in general, they are marine and prefer anaerobic conditions. ectothiorhodospiraceae are a vibrio bacteria that require salty living conditions to survive and grow: classifying them as slightly halophilic. like all purple sulfur bacteria, they are capable of photosynthesis. to complete this energy process, sulfur compounds are used as electron donors for carbon fixation in the pentose phosphate pathway. this elemental sulfur accumulates outside of the cells. ectothiorhodospiraceae scientific classification domain: bacteria phylum: pseudomonadota class: gammaproteobacteria order: chromatiales family: ectothiorhodospiraceae genera acidihalobacter cárdenas et al. 2015 alkalilimnicola corrig. yakimov et al. 2001 "alkalispirillum" rijkenberg et al. 2001 aquisalimonas márquez et al. 2007 arhodomonas adkins et al. 1993 ectothiorhodosinus gorlenko et al. 2007 ectothiorhodospira pelsh 1936 (approved lists 1980) "ca. endonucleariibacter" corrig. dirren et al. 2014 halofilum xia et al. 2017 halorhodospira imhoff and süling 1997 inmirania slobodkina et al. 2016 "maricoccus" li et al. 2013 methylohalomonas sorokin et al. 2007 methylonatrum sorokin et al. 2007 natronocella sorokin et al. 2007 natronospira sorokin et al. 2017 nitrococcus watson and waterbury 1971 (approved lists 1980) oceanococcus li et al. 2014 "ca. ovatusbacter" dirren and posch 2016 spiribacter león et al. 2014 thioalbus park et al. 2011 thioalkalivibrio corrig. sorokin et al. 2001 thiogranum mori et al. 2015 thiohalomonas sorokin et al. 2007 thiohalospira sorokin et al. 2008 thiorhodospira bryantseva et al. 1999 ectothiorhodospiraceae mobilis table of characteristics test type test characteristics colony characteristics size 0.7-1.0μm morphological character shape short spiral/ bent rod gram - physiological character motility + nacl optimum % 2-3 ph optimum 7.6-8.0 acid produced from hydrogen + sulfide + lactate +/- acetate + malate + succinate + ethanol - propanol - note: + = positive, - = negative