Abstract
Purpose Phenyl acetyl carbinol (PAC) is an intermediate for the synthesis of active pharmaceutical ingredients(ephedrine, pseudoephedrine, norephedrine etc.)which are used for the production of antiasthematics and decongestants. Chemical production of these APIsand extraction from plantis costly and cumbersome. Biosynthesis ofPACthrough condensation of benzaldehyde and acetaldehyde using PDC, amore effective method, is being used. These solvents can adversely inhibit PDC. Optimization of cointeraction of significant factors was done through Response surface methodology (RSM) in relatively short time.Method The effect of incubation time (8-18hrs), temperature (30-38oC), pH (4-10) and Inoculum size (4-10%,v/v)on PAC yield, sugar consumption and PDC activity was determined.PAC was quantifiedSpactrophotometerically and HPLC.All results and models were statistically analysed. PDC,produced in 5L flask using molasses as substrate, was exposed to 40mM benzaldehyde as whole cells, crude extract and partialy purified to determine its half life as residuel activity.Results PDC activity and PAC yield were 56.27 U/ml and 8.44 g/L, respectively. The yield of PAC(2.22 to 8.44g/L) was increased by 71% after process optimization through RSM with time (13hrs), temperature(33°C) and total sugar conc. (18%,v/v) as significant factors (p-values, 0.902, 0.260 and 0.247, respectively). Process design had Adj R2 0.562, R-Squared 0.770, Adeq Precision 4.888 with a uniformly distributed standard error.PDC used in the form of Pichia cecembences cells revealed higher stability towards benzaldehyde and temperature as compared to partially purified PDC.Whole cells and partially purified PDC showed half-lives of 240 and 72hrs at 4oC whereas, 33 and 28.5hrs at 25oC. PAC,purity though HPLC was 76.18%. Conclusions Time, temperature and sugar were significant factors as they increased the PAC biosynthesis.PDC from Pichia cecembences(crabtree negative;reported in other publication by same authors), as a whole cell and purified showed better half-lives at 4 and 25oC as compared to reported PDCs.Hence, it is a promising candidate for commercial production of PAC, as its PDC was stable at 4 and 25oC in presence of Benzaldehyde.