**2. Transformation of soybean oil to supramolecular structuresa biomediated process**

The present chapter covers the formation of various supramolecular structures from vegetable oils by microbial product mediated process. The experiments conducted in our laboratory revealed *in situ* transformation of vegetable oils to self-assembled different supramolecular structures viz., vesicle, stable vesicle, supramolecular capsules, colloidosomes, self-healing material, supramolecular rubber like material, organogels, sheet/ flims, bioadhesives, etc., mediated through microbial products. Three different experimental setups were run. In the first set of experiments, microbes were directly used for the transformation of vegetable oil to supramolecular structures. For the second set up, instead of microbes, microbial products were used. The third sets of experiments were executed without any microbes and microbial products but prior to exposure to the medium, the oil was heated at 100 C.

Soybean and sunflower oil are directly procured from the manufacturers and used as a source for triglycerides. Microbes used in the present study are from the varied sources; marine and clinical origin. Microbial products are also from media suppliers; HiMedia Laboratories Pvt. Ltd and MERCK Ltd. The media used for present study are (i) mineral medium comprises of 1 g NH4NO3; 2.55 g NaH2PO4; 0.5 g MgSO4·7H2O; 0.1 g CaCl2·H2O; 0.02 g MnSO4·H2O; 1 g Peptone; 0.5 g Glucose; Zobell marine broth containing 5g Peptic

Transformation of Soybean Oil to Various Self-Assembled Supramolecular Structures 285

Though, we couldn't observe the complete hydrolysis of oil with that of the lipase produced, however, the unhydrolyzed oil further solubilized by the released surface-active agents and interact with the already formed vesicles and helps in the assembly of vesicles. In addition, in the case of the chosen oils, the presence of lecithin increases the supramolecular selfassembly results with the increased gellation with multilamellar vesicles. The release of amino acids during the growth of the microorganism may also involved in the

Multilamellar stable vesicles with different shapes and size formation starts with the micelle formation in the zobell marine broth during the growth of marine *Bacillus* sp. Though internal component facilitates the bilayer formation it has been followed by transformation to multilayer and then thickening of oil. In the present study, the external physical agitation (200 rpm), accelerates the transformation of multilayer vesicles (microscopic) to stable macroscopic structures. The varied macroscopic morphological patterns and the stability observed (spherical to cylindrical shapes) might be due to the available interactions between the components of the medium. The cylindrical morphology observed in the present study may be due to the aggregation of micelles followed by transformation to multilamellar vesicles or the bilayer formation followed by aggregates rolled and transformed to rod like

According to Yan et al., (2009), bipolar nature of amphiphilic is mostly responsible for multilamellar vesicles. The hydrophobicity of released fatty acids mediates the close arrangement with biosurfactants molecule or it may be due to the non-ionic nature of biosurfactants leads to the layer-by-layer formation resulting with multilayer structures. Further, difference in the ratio of number of molecules in the monolayer or bilayers also decides the shape of the vesicles. The reasons for the different macroscopic structures generated could also be explained by (i) decrease in electrostatic interaction and other forces at the bifurcation time; (ii) presence of sensitive reaction diffusion system and (iii) presence of gravity or electric or magnetic fields; (iv) other factors responsible for the weak orientation and finally (v) mismatching of hydrophilic heads of biosurfactants. In addition, self-assembly formed in the experiments is neither uni-directional nor multi-directional, due to the continuous generation of biosurfactants, fatty acids, protein and carbohydrates resulting with assumed morphological features in the solutes. Jiang et al., (2006) reported macroscopic self-assembly of hyper-branched polyester by simple solvent volatilizing route and obtained multi-walled strucutres with millimeter in diameter and centimeters in length. They also found nature of the solvent ratio of the solution, temperature, and molecular concentrations are the parameters deciding the self-assembly of macroscopic structures. Nevertheless, the surface of the self-assembly obtained in the present study is uniform, nonsticky and flexible, emphasizes, formation of MLV initiated with the formation of unilayer by the components as explained above followed by multilayer formation by action of external agents like agitation and finally transformed to stable macroscopic structures. The less bound water (<3%) in the individual macro-structures may be due to the dehydration of head groups, results with the decrease in effective area per molecule at interface (Singh et al., 2009). Further, we observed, salts present in the medium, also responsible for the

**2.2 Transformation of soybean oil to multilamellar stable vesicles (MLSV)** 

transformation of vegetable oil to vesicles.

giant vesicle with concentric rings.

stability of macroscopic structures.

digest of animal tissues; 1g yeast extract; 0.1g ferric citrate; 19.45g sodium chloride; 8.8g magnesium chloride; 3.24g sodium sulphate; 1.80g calcium chloride; 0.55g potassium chloride; 0.16g sodium bicarbonate; 0.08g potassium bromide; 0.034g; strontium chloride; 0.022 boric acid; 0.004 sodium silicate; 0.0024g sodium fluorate; 0.0016g ammonium nitrate; 0.008g disodium phosphate.

The selective microorganisms; marine *Bacillus* sps and clinical strain *Candida albicans* are cultured in the selective medium with triglycerides at different volumes (0.5, 1.0, 1.5, 2.0, 2.5, 4, 6, 8 and 10% w/v) and at cell concentration of 1X 105 cells per ml and incubated for the period of 5-10 days under shaking/ agitation at 180-200 rpm. Followed by inoculation, observations on cell growth, pH profile, hydrolytic enzyme production, fatty acids and glycerol release, surface-active agent production, transformation of oil, micelle formation, nano vesicle to macrosize supramolecular structures were made. The descriptions on various supramolecular structures are briefly explained below:
