Anaerobic biodegradation of pristane by a marine sedimentary bacterial and/or archaeal community

Pristane was incubated in anaerobic sediment slurries under conditions prom oting or limiting nitrate reduction. Pristane was efficiently degraded (85% after 6 months) by the mixed microbial community when nitrate reducing pro cesses were avoided. The biodegradation of pristane was accompanied by the abundant production of methane which indicated that methanogenic Archaea we re involved in the degradation of the substrate. Comparison of the biodegra dation rate of pristane with that of unsaturated isoprenoid alkenes indicat ed that, in Recent anoxic sediments, acyclic isoprenoid alkanes can also un dergo relatively rapid biotransformations and, therefore, can no longer be considered as recalcitrant biomarkers. (C) 2000 Elsevier Science Ltd. All r ights reserved.