5-10 cm depth sample  aerobically incubated for 6 days with 1 mM testosterone R2
The 5-10 cm depth of sediment sample mixed with the estuary water (1:10;1 L) were incubated with 1mM testosterone in 1.2-L glass bottles sealed with a rubber stopper. The headspace (ca. 200 ml) consisted of gas (N2:CO2 = 4:1). This treatment was anaerobically incubated at 25˘XC with stirring at 160 rpm for eight days. Samples (10 ml) were withdrawn at 6 days and were stored at -80˘XC