Sir, Ali Doryab I want to design the bioreactor for production of different acids such as citric acid, I am planning to do it on small scale.

Check the Works of Lonsane TK at Mysore, or Mitchell DE at Curitiba, Paraná (Brazil) and also Saucedo-Castañeda G at México DF. They have published results on the design criteria for tray reactors.

The rule of thumb is simple: shallow (< 3 cm) and porous beds, made of cheap substrates such as wheat bran with 60% humidity.

The problem is loading and unloading many of those trays in a clean environment to prevent undesirable microbial infections.

Best industrial solution was developed by Biocon Ltd using mechatronic technology at Bangalore. The original patent is about to expire and can be copied readily pretty soon. They produced lovastatin pharmaceutical grade using A. terreus. Check the patents in  www.lens.org. Look for patent US_6197573_B1  The priority date is 1998. It will expire at 2018.

The best published work on citric acid by SSF was written by the late Tauro et al. (1975). They used sugar cane bagasse. There are very ancient reports on citric acid production by SSF since before the Second World War. However, no one has ever managed to scale-up citric acid production by SSF perhaps because of inherent mechanical limitation of loading and unloading and leaching large volumes of mash. You need to look for more expensive products in order to cope with scale-up problems. Biocon people produced lovastatin and mycophenolic acid and made a lot of money using SSF processes.

Check

Lakshminarayana, K., Chaudhary, K., Ethiraj, S., & Tauro, P. (1975). A solid state fermentation method for citric acid production using sugar cane bagasse. Biotechnology and Bioengineering, 17(2), 291-293.

I hope this advice is of some help to you.

Best wishes, Gustavo Viniegra ([email protected]).

I agree with all answers above .

Dear researcher

Bioreactors differ from conventional chemical reactors in that they support and control biological entities. As such, bioreactor systems must be designed to provide a higher degree of control over process upsets and contaminations,since the organisms are more sensitive and less stable than chemicals.

http://people.clarkson.edu/~wwilcox/Design/reactbio.pdf

Regards