Response of mixed microbial culture to 2,6-dihydroxybenzoic acid and peptone mixture at low sludge age—effect of culture history

Abstract

The study evaluated the response of an enriched microbial culture on 2,6-dihydroxybenxoic acid (2,6-DHBA) and peptone mixture at low sludge age (theta(X)) under aerobic conditions. It emphasized the effect of culture history by comparing the response of the microbial culture sustained at identical conditions but at two different theta(X) of 2 and 10 days. The fate and impact of continuous 2,6-DHBA addition were evaluated by means of changes induced on the oxygen uptake rate profiles. The acute impact of 2,6-DHBA drastically changed with the culture history. It only inhibited the utilization of the readily biodegradable COD fraction but maintained the overall stoichiometry of substrate removal at a theta(X) of 2 days, while blocking microbial activity with only partial substrate utilization when the theta(X) was 10 days. After four days of continuous 2,6-DHBA feeding, the microbial culture was acclimated providing simultaneous removal for peptone and 2,6-DHBA. The acclimation period was apparently a function of the theta(X) and it was shorter than 10 days. Evaluation of the oxygen uptake rate profiles indicated that acclimation resulted in the development of a dual microbial community with the selective growth of another group of biomass equipped with the enzymatic tools for utilizing 2,6-DHBA as an organic carbon source.

Biodegradation kinetics of peptone and 2,6-dihydroxybenzoic acid by acclimated dual microbial culture

“…Furthermore, it can be easily adjusted to sustain the same characteristics throughout the experiments. Different phases of the study covered the following: (i) biodegradation kinetics of peptone mixture (Orhon et al, 2009a); (ii) the adverse impact of continuous 2,6-DHBA feeding on peptone mixture utilization and acclimation of the mixed culture to 2,6-DHBA (Orhon et al, 2009b) and the effect of sludge age on the impact of 2,6-DHBA (Katipoglu et al, 2010). The objective of the study was to assess the biodegradation kinetics of the peptone/2,6-DHBA mixture by an acclimated microbial culture.…”

Is the naphthalene sulfonate H-acid biodegradable in mixed microbial cultures under aerobic conditions?

“…A peptone-meat extract mixture, referred as peptone mixture in the text for simplicity was selected mainly because it is the standard organic carbon source for the ISO inhibition tests (ISO 8192, 2007) and it may be used with the same characteristics in the experiments. The biodegradation characteristics of the peptone mixture are well tested and documented in the literature and quite similar to those associated with domestic sewage (Insel et al, 2006;Katipoglu et al, 2010).…”

Fate and effect of xenobiotics on biodegradation processes: basis for respirometric appraisal

“…The reported study explored the fate and effect of H-acid using a similar respirometric analysis [20]. A peptone-meat extract mixture was used as the standard organic substrate, mainly because its biodegradation characteristics are well studied and are quite similar to those defining domestic sewage [21,22].…”