, PAUL KLAASSEN , IDA J.DER KLEI , MARTEN VEENHUIS and JAN A.KIEL _BMC Biotechnology_ 2008, 8:29doi:10.Published: 19 March 2008 ABSTRACT (PROVISIONAL) Background Beta-lactams like penicillin and cephalosporin are among the oldest known antibiotics used against bacterial infections.Penicillin is produced by the filamentous fungus Penicillium chrysogenum.Goal is to introduce the entire penicillin biosynthesis pathway into the methylotrophic yeast Hansenula polymorpha.Species have the advantage of being versatile, easy to handle and cultivate, and possess superior fermentation properties relative to filamentous fungi.Of the fundamental challenges is to produce functionally active enzyme in H. Results The P.PcbC gene encoding isopenicillin N synthase (IPNS) was successfully expressed in H.But the protein produced was unstable and inactive when the host was grown at its optimal growth temperature (37 degrees C).Produced IPNS protein levels were enhanced when the cultivation temperature was lowered to either 25 degrees C or 30 degrees C.IPNS produced at these lower cultivation temperatures was functionally active.Experiments demonstrated that, like in P.H.IPNS is located in the cytosol.Conclusions In P.The enzymes involved in penicillin production arepartmentalized in the cytosol and in microbodies.This study, we focus on the cytosolic enzyme IPNS.Show that high amounts of functionally active IPNS enzyme can be produced in the heterologous host during cultivation at 25 degrees C, the optimal growth temperature for P.This is a new step forward in the metabolic reprogramming of H.To produce penicillin.Read more Noninvasive quantitation of drug concentration in prostate and seminal vesicles: improvement and validation with desipramine and aspirin
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