Synthesis of polyhydroxyalkanoates in pseudomonas putida using systems

Abstract

Pseudomonas putida is a versatile microorganism for Polyhydroxyalkanoates (PHA) production. Initially, studies were carried out with the production strain using six different carbon sources to assess the newlineproductivity levels of PHA. The carbon sources are categorized into newlinestructurally related substrates and structurally unrelated substrates. In newlinestructurally related fatty acids, P. putida accumulated PHA under octanoic newlineacid (30 %), lauric acid (35.4%), oleic acid (41.9%), and linoleic acid (45.2 newline%). In the case of structurally un-related substrates P. putida yielded PHA newlinewith glycerol (15.2 %) and glucose (14.8%). Structure of PHA was confirmed newlineby FTIR for all carbon sources. Further, PHA production in batch cultivation newlinemode was performed in 2 L bioreactor with following carbon sources. newlineMaximum productivity of PHA was observed using Linoleic acid (38 %) newlinefollowed by glycerol (16.9 %) and glucose (9.5 %) from the total biomass. newlineAbove, experimental results clearly showed that P. putida achieved the newlinemaximum PHA from linoleic acid, however, the usage of linoleic acid is newlinerelatively expensive in PHA production process. Next highest PHA productivity was achieved by P. putida when cultured with glycerol as a carbon source. As glycerol is a major by product of biodiesel industry, the utilization of glycerol could be an attractive carbon source for PHA production. However, the volumetric productivity of PHA from these substrates are challenging due to the requirement of higher nitrogen limitation, lower PHA yield and by product formation which newlineprevents the usage of these structurally non- related substrates newline newline