title: Wastewater sludge as a potential raw material for antagonistic fungus (Trichoderma sp.): role of pre-treatment and solids concentration.
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.
authors.affiliation: INRS-ETE, Université du Québec, 490, Rue de la Couronne, Québec, Canada G1K 9A9.
authors.forename: Mausam
authors.initials: M
authors.lastname: Verma
authors.forename: Satinder K
authors.initials: SK
authors.lastname: Brar
authors.forename: R D
authors.initials: RD
authors.lastname: Tyagi
authors.forename: J R
authors.initials: JR
authors.lastname: Valéro
authors.forename: R Y
authors.initials: RY
authors.lastname: Surampalli
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D015169:Colony Count, Microbial; D003247:Conservation of Natural Resources; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007814:Larva; D007915:Lepidoptera; D010447:Peptide Hydrolases / Q000378:metabolism; D010572:Pest Control, Biological; D012722:Sewage / Q000009:adverse effects / Q000032:analysis / Q000382:microbiology*; D014242:Trichoderma / Q000254:growth & development / Q000378:metabolism* / Q000472:pathogenicity*; D014865:Waste Disposal, Fluid / Q000379:methods
chemical_list: D012722:Sewage; D010447:Peptide Hydrolases