Applied Biochemistry and Biotechnology

, Volume 148, Issue 1, pp 211–226

Selective Enrichment of a Methanol-Utilizing Consortium Using Pulp and Paper Mill Waste Streams

  • Gregory R. Mockos
  • William A. Smith
  • Frank J. Loge
  • David N. Thompson
Article

DOI: 10.1007/s12010-007-8028-8

Cite this article as:
Mockos, G.R., Smith, W.A., Loge, F.J. et al. Appl Biochem Biotechnol (2008) 148: 211. doi:10.1007/s12010-007-8028-8

Abstract

Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater. Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste-activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of 4 days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24-h feed/decant cycles ranged from 79 to 89%, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste-activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen-limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen-limited conditions. This indicates that selectively enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

Keywords

Foul condensateWaste-activated sludgePolyhydroxyalkanoatesPulp millNatural fiber reinforced thermoplastic composite

Copyright information

© Humana Press Inc. 2007

Authors and Affiliations

  • Gregory R. Mockos
    • 1
  • William A. Smith
    • 2
  • Frank J. Loge
    • 1
  • David N. Thompson
    • 2
  1. 1.Department of Civil and Environmental EngineeringUniversity of California at DavisDavisUSA
  2. 2.Biological Sciences DepartmentIdaho National LaboratoryIdaho FallsUSA