Fermentation-Based Biosynthesis of Polyunsaturated Fatty Acids by Endophytic Microorganisms of Portulaca oleracea

Abstract

As the human body is incapable of synthesizing polyunsaturated fatty acids (PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), they must be obtained from the diet. Heavy metal contamination of PUFA from fish oils and production limitations of PUFA-producing plants demand the investigation of alternative sources. PUFA produced from microbes has recently attracted great interest, due to the efficiency of synthesis and scalability, and hence could be an alternative source of PUFA. This research used a culture-dependent approach for enumerating microorganisms from distinct plant sections of the plant Portulaca oleracea. Cultures were isolated and evaluated for their potential for producing PUFA using the Bligh and Dyer technique and gas chromatography. This is the first time PUFA-producing microorganisms have been identified from the Portulaca oleracea. Four out of 31 endophytes isolated were found capable of synthesizing PUFAs. Of the selected isolates, RSMAB-1 and MD cultures produce 8.8 and 10.83 mg of PUFA, 3.2 and 2.63 mg of EPA, and 0.12 and 0.25 mg of DHA per 100 mg of fatty acids, respectively. These cultures were identified as Bacillus subtilis and Saccharomyces cerevisiae, respectively. The current primary source of PUFA has limited production capacity, making microorganisms an excellent option for PUFA synthesis. In the current investigation, it was determined that four cultures create distinct forms of PUFA. Two of the chosen cultures had the highest PUFA output. This work emphasizes the significance of screening endophytes from PUFA-producing plants for their capacity to produce PUFA.

KEYWORDS:

Endophytes, Portulaca oleracea, EPA, PUFA, Bacillus subtilis.