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

The degradation of mono- and dichlorobenzoates was followed in soil suspens ions. 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 highl y accelerated. The presence in the soil suspensions of other chlorobenzoate s (CBs) together with 4CB affected the degradation rate of the latter compo und: 2CB and 2,6-dichlorobenzoic acid (2,6-DCB) retarded the degradative pr ocess, while 3,4- or 2,3-dichlorobenzoic acids (3,4-, 2,3-DCB) totally inhi bited 4CB degradation. The potential mechanisms involved in these interacti ons are discussed. (C) 1999 Federation of European Microbiological Societie s. Published by Elsevier Science B.V, All rights reserved.