A hundred and twenty eight Bacillus circulans like isolates were collected from the soil or rhizosphere of plants grown in seven Egyptian governorates. All isolates were examined for enzymatic expression of amylase, pectinase, cellulase and phosphatase. The six most expressive isolates were subjected for further examination of chitinase production and then identified by Biologe identification system. Four isolates identified as Bacillus circulans were used as bio-accelerating mixture in composting of broad bean stalks, maize stalks and rice straw. The physical, chemical and microbiological changes during composting of the 3 wastes were compared under the application of variable combinations of biological, organic and inorganic accelerator. The quality of biological composted rice straw was evaluated as an organic amendment for potato and broccoli under organic farming condition. Evaluation comprised a comparison of the effects of biologically composted rice straw with the recommended dose of chicken manure and also those effects in relation to increase applied rates of the compost. Application of the biologically composted rice straw was always superior to that of chicken manure.