Demonstrating the In Situ Biodegradation Potential of Phenol Using Bio‐Sep^® Bio‐Traps^® and Stable Isotope Probing

Abstract

The effect of phenol concentration on phenol biodegradation at an industrial site in the south of Wales, United Kingdom, was investigated using standard Bio-Sep ® Bio-Traps ® and Bio-Traps ® coupled with stable isotope probing (SIP). Unlike many 13 C-amendments used in SIP studies (such as hydrocarbons) that physically and reversibly adsorb to the activated carbon component of the Bio-Sep ® beads, phenol is known to irreversibly chemisorb to activated carbon. Bio-Traps ® were deployed for 32 days in nine site groundwater monitoring wells representing a wide range of phenol concentrations. Bio-Traps ® amended with 13 C-phenol were deployed together with non-amended Bio-Traps ® in three wells. Quantitative polymerase chain reaction (qPCR) analysis of Bio-Traps ® post-deployment indicated an inhibitory effect of increasing phenol concentration on both total eubacteria and aerobic phenol-utilizing bacteria as represented by the concentration of phenol hydroxylase gene. Despite the chemisorption of phenol to the Bio-Sep ® beads, activated carbon stable isotope analysis showed incorporation of 13 C into biomass and dissolved inorganic carbon (DIC) in each SIP Bio-Trap ® indicating that chemisorbed amendments are bioavailable. However, there was a clear effect of phenol concentration on 13 C incorporation in both biomass and DIC confirming phenol inhibition. These results suggest that physical reductions of the phenol concentrations in some areas of the plume will be required before biodegradation of phenol can proceed at a reasonable rate. O

Two decades of warming increases diversity of a potentially lignolytic bacterial community

“…Instead, higher oxidative enzyme activity in the unamended beads may be due to their better suitability for fungal colonization. DeAngelis et al previously noted that fungi formed a smaller fraction of the eukaryotic community in lignin amended than unamended beads, and the small pores on the exterior of Bio-Sep beads have been reported to limit eukaryotic access (Williams et al, 2013 ). We observed that lignin amended beads are 44% denser than unamended beads, indicating that lignin amendment may have made it even more difficult for larger organisms to colonize the interior of the beads.…”

“…Bio-Sep beads are ~3–4 mm diameter porous spheres consisting of activated charcoal (25%) in a Nomex matrix (75%) (Williams et al, 2013 ). The beads are biochemically inert but are able to sorb nutrients.…”

“…Selected substrates can be attached to the surfaces of the beads by covalent bonding via a proprietary method that enables microbial access to substrates while preventing leaching. Bio-Sep beads have been used in aquatic systems (Anderson et al, 2003 ; Peacock et al, 2004 ; Sublette et al, 2006 ; Baldwin et al, 2008 ; Williams et al, 2013 ) as well as terrestrial systems (DeAngelis et al, 2011 ; Omotayo et al, 2011 ) to monitor microbial activity. Bead pouches used in this study consisted of 5 g (~20 ml) of Kraft lignin amended or unamended beads in an 8 cm diameter circular window screen mesh pouch (Phifer silver gray fiberglass screen, product 4788811608, approximately 1 mm mesh size) that was heat-sealed.…”

Molecular analysis of atrazine-degrading bacteria and catabolic genes in the water column and sediment of a created wetland in an agricultural/urban watershed

“…The beads were made of granular activated carbon compressed into size and shape of lentils (Sublette et al, 1996;Peacock et al, 2004;Williams et al, 2013). The technique is based on sorption of atrazine in aqueous solution on the beads followed by in-situ incubation to enrich for atrazine-degrading bacteria, possibly in the form of biofilm growth (Mehta et al, 2004;Peacock et al, 2004;Ghosh et al, 2009;Omotayo et al, 2011).…”

The Effect of an Adsorbent Matrix on Recovery of Microorganisms from Hydrocarbon-Contaminated Groundwater

“…This approach has been reported in several studies which have shown the efficacy of using solid support materials to sample microorganisms in subsurface environments that may be contributing to hydrocarbon metabolism [ 26 ]. Materials such as granular activated carbon [ 25 ] and Bio-Sep ® beads (comprised of activated charcoal in a polymer matrix, [ 27 ]) have been successfully used to sample microorganisms from hydrocarbon-contaminated groundwater environments for microbial community member identification [ 24 , 28 , 29 , 30 ]. Further, materials such as the Bio-Sep ® beads have been incorporated into commercially available Bio-Trap ® samplers (Microbial Insights, Knoxville, TN, USA).…”