Wastewater sludge as a potential raw material for antagonistic fungus (Trichoderma sp.): role of pre-treatment and solids concentration

Water Res. 2005 Sep;39(15):3587-96. doi: 10.1016/j.watres.2005.07.001.

Abstract

Feasibility of production of antagonistic Trichoderma sp. conidial spores using wastewater sludge as a raw material employing different suspended solids concentration (10-50 g/l) was investigated in shake flasks. Maximum conidial spore count obtained for raw sludge was 1.98 x 10(4) CFU/ml, which was enhanced by sludge pre-treatments (alkaline and thermal alkaline). Conidial spore count ranging from 1.3 x 10(6) to 2.8 x 10(7) CFU/ml was observed for alkaline and thermal alkaline treated sludges. Optimal suspended solids concentration was 30 g/l (10(7) CFU/ml) whereas, lower (<20 g/l) and higher (>30 g/l) solids concentration were less efficient. Thermal alkaline pre-treated sludge showed diauxic growth due to multiplicity of sludge biodegradability. A simple, modified CFU filtration technique was also developed for fungal spore assessment in sludge. Bioassay of fermented sludge against spruce budworm larvae showed entomotoxicity (15036 SBU/microl), on par with Bacillus thuringiensis biopesticides. This study successfully demonstrated potential of wastewater sludge as a raw material for production of value added product, aiding in sludge management and proliferation of eco-friendly and economical biocontrol agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodegradation, Environmental
  • Colony Count, Microbial
  • Conservation of Natural Resources
  • Hot Temperature
  • Hydrogen-Ion Concentration
  • Larva
  • Lepidoptera*
  • Peptide Hydrolases / metabolism
  • Pest Control, Biological*
  • Sewage / adverse effects
  • Sewage / analysis
  • Sewage / microbiology*
  • Trichoderma / growth & development
  • Trichoderma / metabolism*
  • Trichoderma / pathogenicity*
  • Waste Disposal, Fluid / methods

Substances

  • Sewage
  • Peptide Hydrolases