Soil obtained from a beech forest formed significant amounts of acetat
e when incubated in a bicarbonate-buffered, mineral salt solution unde
r anaerobic conditions at both 5 and 20-degrees-C (21 and 38 g of acet
ate per kg [dry weight] of soil, respectively). At 20-degrees-C, follo
wing an 18-day lag period, rates of 0.07 mmol of acetate synthesized p
er g (dry weight) of soil per day were observed. Acetate was not subje
ct to immediate turnover; methane and hydrogen were not formed during
the time intervals (5-degrees-C, 335 days; 20-degrees-C, 95 days) eval
uated. The synthesis of acetate from endogenous materials was coincide
nt with acetogenic potentials, i.e., the capacity to catalyze the H-2-
dependent synthesis of acetate. Hydrogen consumption was not directed
towards the synthesis of methane. Collectively, these results suggest
that acetogenesis may be an underlying microbial activity of this fore
st soil.