Methyl Stearate

Statistical optimization for lipase production from solid waste of vegetable oil industry.[Pubmed:29424632]

Prep Biochem Biotechnol. 2018 Apr 21;48(4):321-326.

The production of biofuel using thermostable bacterial lipase from hot spring bacteria out of low-cost agricultural residue olive oil cake is reported in the present paper. Using a lipase enzyme from Bacillus licheniformis, a 66.5% yield of methyl esters was obtained. Optimum parameters were determined, with maximum production of lipase at a pH of 8.2, temperature 50.8 degrees C, moisture content of 55.7%, and biosurfactant content of 1.693 mg. The contour plots and 3D surface responses depict the significant interaction of pH and moisture content with biosurfactant during lipase production. Chromatographic analysis of the lipase transesterification product was methyl esters, from kitchen waste oil under optimized conditions, generated methyl palmitate, Methyl Stearate, methyl oleate, and methyl linoleate.

Demonstration of bioprocess factors optimization for enhanced mono-rhamnolipid production by a marine Pseudomonas guguanensis.[Pubmed:29208557]

Int J Biol Macromol. 2018 Mar;108:531-540.

We identified that Pseudomonas guguanensis produced macromolecular mono-rhamnolipid (1264.52Da) upon sensing n-hexadecane/diesel/kerosene from its surroundings. Permutation experiments were done to improve the laboratory-scale mono-rhamnolipid production (ie, a three-fold increase) using RSM validation. Consequently, maximal mono-rhamnolipids production [40-50mg/L] and emulsification abilities [65-70%] were encountered on day 8 using vegetable oil, peptone+yeast extract. EI24 values for the rhamnolipids were found to be 78+/-1.75% at 12.5mg/mL. Production and secretion of rhamnolipids were accompanied by aggregation of cells at day 6 as pictured in SEM. Pure monorhamnolipids of P. guguanensis was found to lower the surface tension of water to 32.98+/-0.3mN/m than the crude and CFSs of P. aeruginosa indicating efficient activity. Utilization and subsequent removal of hexadecane was 77.2% and the breakdown products were fatty acids [decanoic, hexadecanoic, octadecanoic acids and Methyl Stearates] as signified in Head-space GC-MS. The breakdown products of hexadecane are also present in the synthesized rhamnolipids suggesting their biosynthetic role. Rapid degradation of hexadecane, diesel and kerosene by this emulsifier combined with non-pathogenic trait of P. guguanensis identifies this organism as a viable option to remove n-alkanes from aquatic environments.

Phosphatidylinositol 4,5-bisphosphate, cholesterol, and fatty acids modulate the calcium-activated chloride channel TMEM16A (ANO1).[Pubmed:29277655]

Biochim Biophys Acta Mol Cell Biol Lipids. 2018 Mar;1863(3):299-312.

The TMEM16A-mediated Ca(2+)-activated Cl(-) current drives several important physiological functions. Membrane lipids regulate ion channels and transporters but their influence on members of the TMEM16 family is poorly understood. Here we have studied the regulation of TMEM16A by phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), cholesterol, and fatty acids using patch clamp, biochemistry and fluorescence microscopy. We found that depletion of membrane PI(4,5)P2 causes a decline in TMEM16A current that is independent of cytoskeleton, but is partially prevented by removing intracellular Ca(2+). On the other hand, supplying PI(4,5)P2 to inside-out patches attenuated channel rundown and/or partially rescued activity after channel rundown. Also, depletion (with methyl-beta-cyclodextrin M-betaCD) or restoration (with M-betaCD+cholesterol) of membrane cholesterol slows down the current decay observed after reduction of PI(4,5)P2. Neither depletion nor restoration of cholesterol change PI(4,5)P2 content. However, M-betaCD alone transiently increases TMEM16A activity and dampens rundown whereas M-betaCD+cholesterol increases channel rundown. Thus, PI(4,5)P2 is required for TMEM16A function while cholesterol directly and indirectly via a PI(4,5)P2-independent mechanism regulate channel function. Stearic, arachidonic, oleic, docosahexaenoic, and eicosapentaenoic fatty acids as well as Methyl Stearate inhibit TMEM16A in a dose- and voltage-dependent manner. Phosphatidylserine, a phospholipid whose hydrocarbon tails contain stearic and oleic acids also inhibits TMEM16A. Finally, we show that TMEM16A remains in the plasma membrane after treatment with M-betaCD, M-betaCD+cholesterol, oleic, or docosahexaenoic acids. Thus, we propose that lipids and fatty acids regulate TMEM16A channels through a membrane-delimited protein-lipid interaction.

Thermally Reversible Fluorans: Synthesis, Thermochromic Properties and Real Time Application.[Pubmed:29442831]

J Nanosci Nanotechnol. 2018 May 1;18(5):3299-3305.

In the present study, two fluoran molecules (TH1 and TH2) have been synthesized, and their reversible thermochromic properties have been investigated. This work demonstrates the thermochromic reversibility of the fluoran. Furthermore, the three-component mixtures that comprising fluorans (TH1/TH2), bisphenol-A (color developer), and Methyl Stearate a low melting solvent were used to examine the thermochromic behavior with sturdy heating and cooling rates and the thermochromic properties of the fluorans were detailed using UV-Vis, reflectance and FT-IR spectroscopic techniques. Finally, test strip similar to pH paper and acrylic fiber a versatile material used as thermal indicators also been successfully made from these two fluoran derivatives.