international Journal of Systematic Bacteriology (1 999), 49, 1 63 1-1 643 Printed in Great Britain Psychrophi Iic sulf ate-reducing bacteria isolated from permanently cold Arctic marine sediments : description of Desulfofrigus oceanense gen. nov., sp. nov., Desulfofrigus fragile sp. nov., Desulfofaba gelida gen. nov., sp. nov., Desulfotalea psychrophila gen. nov., sp. nov. and Desulfotalea arctica sp. nov. Christian Knobtauch, Kerstin Sahm and Bo B. Jcbrgensen Author for correspondence: Christian Knoblauch. Tel: +49 421 2028 653. Fax: +49 421 2028 690. e-mail :
[email protected] Max-PIa nc k-I nst it Ute for Five psychrophilic, Gram-negative, sulfate-reducing bacteria were isolated Mari ne M icro bio logy, from marine sediments off the coast of Svalbard. All isolates grew at the in Celsiusstr. 1, 28359 Bremen, Germany situ temperature of -1.7 "C. In batch cultures, strain PSv29l had the highest growth rate at 7 "C, strains ASV~~~and LSv54l had the highest growth rate at 10 "C, and strains LSv21Tand LS~514~had the highest growth rate at 18 "C. The new isolates used the most common fermentation products in marine sediments, such as acetate, propionate, butyrate, lactate and hydrogen, but only strain ASv26' was able to oxidize fatty acids completely to CO,. The new strains had growth optima at neutral pH and marine salt concentration, except for LSv54l which grew fastest with 1O/O NaCI. Sulfite and thiosulfate were used as electron acceptors by strains ASv26'. PSv29l and LSv54l, and all strains except PSv29' grew with Fe3+(ferric citrate) as electron acceptor. Chemotaxonomy based on cellular fatty acid patterns and menaquinones showed good agreement with the phylogeny based on 165 rRNA sequences.