The role of physical support in secondary metabolite production by Streptomyces species.

Microbial secondary metabolites are widely applied in many fields as medicines, pesticides, food additives, etc. To produce these compounds, several fermentation methods exist from lab-scale to industrial manufacturing, all of them having different advantages and drawbacks. In this comprehensive review, four types of cultivation techniques - conventional immobilisation, solid-state fermentation and relatively novel methods as microparticle enhanced cultivation and membrane gradostat reactor - have been described. This paper focuses on the importance of physical support both in terms of presence and its impact on the observed microbial processes. The above mentioned methods are described and compared to each other on the basis of the research results of the genus Streptomyces. They were chosen specifically due to their sensitivity to cultivation conditions and their determining position in secondary metabolite production. As a consequence, they are appropriate for observing the role of physical support. Finding a universally applicable technique was not...