TABLE 1.

Summary of properties of vacuolate Beggiatoa and Thioploca spp.

Organism(s)	Filament width (μm)	Common sheath	Vacuole vol. (% of biovolume)	Evidence for vacuolea	Length of 16S ribosomal DNA sequence (bp)	References
Beggiatoa sp. (Monterey Canyon)	65–85	No	80	P/V	1,493	24; this study
Beggiatoa spp. (Guaymas Basin vents)	17–35	No	68–85	P/V, EM	None	29, 31
	32–50	No	83	P/V, EM	None
	88–140	No	92	P/V, EM	None
Thioploca ingrica	2–4.5	Yes	39–42b	EM	1,491	18, 19, 38
Thioploca chileae	12–20	Yes	89b	EM	550	20, 21, 38
Thioploca araucae	30–43	Yes	>80	EM	620	5, 20, 21, 38

^aP/V, protein biovolume ratios (31); EM, electron microscopy. 

^bCalculated from previously published electron micrographs of Thioploca ingrica (19) and T. chileae (21).