In PA-A fermentation, we are not getting the titer more than 2.6 g/L (at 100L scale) or increasing at a very slow rate. At 20L scale we are getting titer 4-5g/L but after 220h of fermentation. How to increase its productivity at 100L? We are doing Fed-Batch fermentation with Glucose feeding. Commercially many groups are following this strategy, first they grow the culture and get the cell mass with glucose feeding and then cut off the glucose (probably to shift the culture to stationery phase). PA-A will be biosynthesized during this phase.