ABSTRACT
Light Weight Aggregates (LWA) (expanded clay particles Liapor R 1-4 mm, Liapor GmbH Germany) were impregnated twice under vacuum with a calcium lactate-(80 g/liter), yeast extract-(1 g/liter) solution, followed by a final impregnation step with a bacterial spore suspension. After each impregnation treatment, expanded clay particles were dried in an oven for 5 days at 37ºC. The impregnated expanded clay particles obtained contained 6% (by weight) calcium lactate and 1.7 * 105 bacterial spores g−1 particles.
