Evaluation of Physarum polycephalum plasmodial growth and lipid production using rice bran as a carbon source.

Hanh Tran,Erik Pollock,Steven Stephenson

doi:10.1186/s12896-015-0188-y

Hanh Tran, Erik Pollock + Show 1 more

Open Access

https://doi.org/10.1186/s12896-015-0188-y

Copy DOI

Abstract

BackgroundThe myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism.ResultsOptimization of medium components by response surface methodology showed that rice bran and yeast extract had significant influences on lipid and biomass production. The optimum medium consisted of 37.5 g/L rice bran, 0.79 g/L yeast extract and 12.5 g/L agar, and this yielded 7.5 g/L dry biomass and 0.9 g/L lipid after 5 days. The biomass and lipid production profiles revealed that these parameters increased over time and reached their maximum values (10.5 and 1.26 g/L, respectively) after 7 days. Physarum polycephalum growth decreased on the spent medium but using the latter increased total biomass and lipid concentrations to 14.3 and 1.72 g/L, respectively.ConclusionsAn effective method for inoculum preparation was developed for biomass and lipid production by P. polycephalum on a low-cost medium using rice bran as the main carbon source. These results also demonstrated the feasibility of scaling up and reusing the medium for additional biomass and lipid production.

Highlights

The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production
Glucose in nutrient agar was replaced with rice bran with the same concentration (5 g/L)
Material taken from the margin of an actively growing plasmodium on nutrient agar/agar is used as an inoculum [6, 7]

Summary

Introduction

The myxomycete Physarum polycephalum appears to have remarkable potential as a lipid source for biodiesel production. The present study evaluated the use of rice bran as a carbon source and determined the medium components for optimum growth and lipid production for this organism. Plant oil commonly has been used as a source of lipids for biodiesel production. Lipid production from a number of microorganisms, including algae, oleaginous yeasts and fungi, have been investigated as possible replacements of plant oil as a more sustainable approach to producing biodiesel, since microorganisms grow more rapidly and make much more efficient use of space. The raw material (oil/lipids) required for biodiesel production is responsible for about 60–75 % of the total cost of producing this type of fuel [1]. Is a member of the order Physarales of the class Myxomycetes, a group of fungus-like eukaryotic organisms commonly known as slime molds. Poulos and Thompson [4] found that P. polycephalum could undergo rapid growth and accumulate a considerable amount of lipids, and Tran et al [5] demonstrated that the lipids

Methods

Results

Conclusion