1. Alexander M (2011) Introduction of soil microbiology, 2nd edn. Krieger, Melbourne
2. Altland JE (2006) Substrate pH, a tricky topic. Digger 50:42–47
3. Aly MM, Tork S, Al-Garni S, Nawar L (2012) Production of lipase from genetically improved Streptomyces exfoliates LP10 isolated from oil contaminated soil. Afr J Microbiol Res 5(29):1125–1137
4. Arshad M, Frankenberger WT (1993) Microbial production of plant growth regulators. In: Meeting FB (ed) Soil microbial ecology. Marcel Dekker, New York, pp 307–347
5. Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress tolerance. Environ Exp Bot 59:206–216