Mixed-culture method oxidization

None of the pure cultures that produced HFBT have been shown to further metabolize this compound. Bohonos et al. (46) found two further oxidation products, 3-hydroxybenzothiophene and 2,3-dihydrobenzothiophene-2,3-dione in aerobic mixed cultures co-metabolizing dibenzothiophene. Recently, Mormile and Atlas (61) inoculated portions of the filter-sterilized supernatant from a dibenzothiophene-degrading culture with soil and sediment samples and observed the loss of HFBT using a spectroscopic method. Under their aerobic growth conditions, they also observed the release of carbon dioxide from these cultures indicating that these products of dibenzothiophene degradation can be further oxidized. In addition, they observed carbon dioxide production from dibenzothiophene-sulfoxide. 

C has been used as a tracer in the study of the degradation of [1-13C]-acenaphthene both in pure cultures that were degrading naphthalene and phenanthrene by cometabolism, and in a mixed culture that was enriched with creosote (Selifonov et al. 1998). The degradation pathway that is initiated by benzylic monooxygenation could be determined by isolation of intermediate metabolites, and the method proved applicable to the situation where only limited biotransformation of the substrates takes place by partial oxidation. 

In one bio-oxidation process, low-grade gold ore is mixed with a brew of bacteria in huge, stirred reactors. A newer process places open piles of gold ore on an impermeable base. Bacterial cultures and the fertilizers needed to nurture them are poured onto the gold ore. In both methods, T. ferrooxidans treats the gold sulfides at a lower cost and with an efficiency of recovery increased from 70 to 95 percent. 

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