Aims: To investigate the effect of pH regulation and nutrient concentration on cephalosporin C (CPC) production in solid-state fermentation (SSF), using sugarcane bagasse as inert support, impregnated with liquid medium.
Methods and results: Solid-state fermentation using different initial pH values, buffer and nutrient concentrations were performed. Results revealed pH as a key parameter in CPC SSF, as it hampered the antibiotic production not only above 7.8, but also under 6.4. Using initial pH lower than 6.8 and PB in the solid medium, it was possible to keep pH within the production range, increase the production period (from 1 to 3 days) and hence the CPC yield from 468 to 3200 microg gdm(-1) (g(-1) of dry matter).
Conclusion: Parameters that help to keep pH in adequate values for CPC production in SSF, such as initial pH, buffering system and nutrient concentration, can greatly increase the production time and CPC yields in this fermentation technique.
Significance and impact of the study: This is the first work on CPC production on impregnated support, and the only one revealing pH as a key parameter; it is also shown that high nutrient concentration can improve CPC yields in SSF as long as pH is kept under control.