In this study, fatty acid feedstock preparation and lactic acid production as integrated processes in mixed restau-rant food and bakery waste treatment were investigated. The treatment included the hydrolysis of waste using extracellular fungal enzymes in submerged fermentation. By hydrolysis, 0.27 g glucose, 4.7 mg free amino nitro-gen (FAN) and 1.9 mg phosphate were recoveredper gram dry wastematerial. After hydrolysis, a lipid-rich solid fraction,tobeusedasasourceoffattyacids,remained.Thenutrient-richhydrolysatewasusedasmediuminfed-batch cultures of the heterotrophic microalga Chlorella pyrenoidosa, which grew well at a rate of 1.4 day−1. In ordertoestablishacost-andwater-efficientprocess,hydrolysisandalgaecultivationwereperformedinrecycled culturesupernatant withoutany negative impacts on the fungal hydrolysisand growthofC.pyrenoidosa. The ex-traction of lipids from algal biomass and lipid-rich solids resulted in a saturated and unsaturated fatty acid-rich feedstock. Defatted waste derived solids and algal biomass were further tested successfully as nitrogen sources in lactic acid production using Bacillus coagulans. The outcomes of this study contribute to the establishment of a ‘green society’ by utilization of waste material in the production of chemicals, materials and fuels.