Degradation of chlorobenzoates in soil suspensions by indigenous populations and a specialized organism: interactions between growth and non-growth substrates

Abstract

The degradation of mono- and dichlorobenzoates was followed in soil suspensions. The indigenous microflora of the soil used was able to degrade only 4-chlorobenzoic acid (4CB) and 2-chlorobenzoic acid (2CB) either added alone or present in a mixture. When the soil was inoculated with an Alcaligenes denitrificans CB strain capable of degrading 4CB, 4CB degradation was highly accelerated. The presence in the soil suspensions of other chlorobenzoates (CBs) together with 4CB affected the degradation rate of the latter compound: 2CB and 2,6-dichlorobenzoic acid (2,6-DCB) retarded the degradative process, while 3,4- or 2,3-dichlorobenzoic acids (3,4-, 2,3-DCB) totally inhibited 4CB degradation. The potential mechanisms involved in these interactions are discussed.