**6. Future perspectives**

The industrial production of androstenedione is challenging and economically important.

Therefore upcoming research in this field will be focused on:


Although there are a number of strains reported to have the biotransformation ability, yet the efficacy of these strains does not match the industrial applicability. Hence the need of the hour is to look for organisms having the capacity of transforming phytosterols to AD with high efficiency. Strategies can be applied for screening microorganisms having the ability to produce natural compounds like biosurfactants which increase the availability of complex substrates. Such organisms might play a role in substrate solubility of phytosterol thus minimizing the need of additional compounds.

Process optimization involves various parameters such as substrate inhibition, product inhibition, activities of biocatalysts, etc. To date, to the best of our knowledge, these parameters have not been addressed in the available literature. These parameters may result in the low yield of AD. Once addressed, these parameters might open a vast area of research. The mechanism of phytosterol biotransformation by various organisms has been reported but the enlisted parameters have not been paid attention to. All the aspects of the process need to be considered so as to develop an industrially applicable process for biotransformation of phytosterols.
