Utilization of pyrene and benzoate in Mycobacterium isolate KMS is regulated differentially by catabolic repression

Abstract

The soil isolate, Mycobacterium sp. strain KMS, utilizes an array of carbon compounds including the aromatics benzoate and pyrene as sole carbon sources. Growth on pyrene induced both chromosomal and plasmid nidA genes encoding pyrene ring‐hydroxylating dioxygenase α‐subunits for pyrene oxidation. Diauxic growth occurred when KMS was cultured with pyrene plus either acetate, succinate, fructose, or benzoate and nidA expression only was detected in the second slower log‐phase period. Potential cAMP‐CRP binding sites exist within the promoter region of both nidA genes indicating that cAMP‐CRP may be involved in catabolite repression of pyrene utilization. When cultured with benzoate plus either acetate, succinate, or fructose, there was no diauxic growth. Also there was no diauxic growth on fructose plus succinate or acetate. Expression of a benA gene, encoding a benzoate dioxygenase α‐subunit involved in the initiation of benzoate oxidation, was detected in log‐phase cells from the benzoate‐mixed substrate cultures at the same level as when the cells were cultured on benzoate alone. These findings suggested that catabolite repression of pyrene but not benzoate occurred in isolate KMS. These differences may help the microbe exploit the varied carbon sources available in the soil and rhizosphere environments.

Short-Term Rhizosphere Effect on Available Carbon Sources, Phenanthrene Degradation, and Active Microbiome in an Aged-Contaminated Industrial Soil

“…This lack of transcriptional induction also suggests that rhizodeposits did not trigger a massive carbon catabolite repression (CCR), which would expectedly yield lower transcription of PAH-RHD genes in planted soil. Purified sugars and root extracts have been shown to inhibit the degradation of aromatic compounds by CCR in several cultivated isolates (Keuth and Rehm, 1991 ; Dal et al, 2002 ; Kamath et al, 2004 ; Rentz et al, 2004 ; Rojo, 2010 ; Zhang and Anderson, 2013 ; Vandera et al, 2015 ). However, it has been suggested that CCR may be more significant when considering a single species of degrader rather than a diverse community (Martin et al, 2014 ).…”

Hierarchy of Carbon Source Utilization in Soil Bacteria: Hegemonic Preference for Benzoate in Complex Aromatic Compound Mixtures Degraded by Cupriavidus pinatubonensis Strain JMP134

“…Altogether, it seems clear that Bz is a distinctive preferred substrate for several soil bacteria. There are, of course, examples of simultaneous degradation in Bz-containing mixtures (14,44), including synergic interactions such as those described in Sagittula stellata E-37, a member of the Roseobacter lineage, where increased growth rates are found for Bz-4-Hb mixtures (45). There are several possible explanations for the preference for Bz over AC, none of them fully satisfactory.…”

A genuine mycobacterial thermophile: Mycobacterium hassiacum growth, survival and GpgS stability at near-pasteurization temperatures

“…Diauxic growth has been reported for the pyrene-degrading isolate Mycobacterium sp. KMS [43, 44] but this nutritional strategy is not used by the model mycobacteria M. smegmatis or M.…”