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Cavitation results in conditions of turbulence and liquid circulation in the reactor which can aid in eliminating mass transfer resistances. The present work illustrates the use of cavitation for intensification of biodiesel synthesis (esterification) reaction, which is mass transfer limited reaction considering the immiscible nature of the reactants, i.e., fatty acids and alcohol. Esterification of fatty acid (FA) odour cut (C(8)-C(10)) with methanol in the presence of concentrated H(2)SO(4) as a catalyst has been studied in hydrodynamic cavitation reactor as well as in the sonochemical reactor. The different reaction operating parameters such as molar ratio of acid to alcohol, catalyst quantity have been optimized under acoustic as well as hydrodynamic cavitating conditions in addition to the optimization of the geometry of the orifice plate in the case of hydrodynamic cavitation reactors. Few experiments have also been carried out with other acid (lower and higher)/methanol combination viz. caprylic acid and capric acids with methanol with an aim of investigating the efficacy of cavitation for giving the desired yields and also to quantify the degree of process intensification that can be achieved using the same. It has been observed that ambient operating conditions of temperature and pressure and reaction times of <3h, for all the different combinations of acid (lower and higher)/methanol studied in the present work, was sufficient for giving >90% conversion (mol%). This clearly establishes the efficacy of cavitation as an excellent way to achieve process intensification of the biodiesel synthesis process.

MacLeod, Patricia (University of Connecticut, Storrs) and Joseph P. Brown. Fatty acid composition of lipids from Streptococcus cremoris and Streptococcus lactis var. maltigenes. J. Bacteriol. 85:1056-1060. 1963.-A method for the extraction of lipids from bacterial cells, involving grinding in a ball mill, is described. Cells of Streptococcus lactis var. maltigenes and S. cremoris yielded 5.3 and 5.5%, respectively, of their dry cellular weights as lipid. The lipids of both organisms were separated into three fractions by thin-layer chromatography. Two of these fractions have been classified: one fraction containing phospho- and perhaps glycolipids and the other containing triglycerides. The unidentified fraction was probably either mono- or diglyceride in nature. The fatty acid composition of the total lipid as well as that of each of the separated lipid components from the two lactic strains were compared.

Huston, Charles K. (U.S. Army Biological Laboratories, Fort Detrick, Frederick, Md.), and Phillip W. Albro. Lipids of Sarcina lutea. I. Fatty acid composition of the extractable lipids. J. Bacteriol. 88:425-432. 1964.-The extractable lipids of Sarcina lutea were separated into several fractions by a combination of column and thin-layer chromatography. Qualitative and quantitative characterization of the fatty acid content of these lipid fractions was accomplished by means of gas-liquid chromatography and infrared analyses. Of the total extract, the lipids consisted of 2.1% free fatty acids, 51.0% glycerides, and 22.7% complex lipids; they had a fatty acid content with a complete spectrum of carbon numbers from C(8) to C(22). The fatty acids included a large component of branched-acids in addition to the normal straight-chain acids. The branched-acids, comprising 40% of the fatty acids analyzed, constituted a homologous series of iso-acids from C(12) to C(19). Two 18-carbon unsaturates were found cis-9-octadecenoate and cis-11-octadecenoate. A relatively high percentage (20.5%) of the extractable material from S. lutea was found to be hydrocarbon. This material was not further characterized.

Anacker, R. L. (National Institute of Allergy and Infectious Diseases, Rocky Mountain Laboratory, Hamilton, Mont.), R. A. Finkelstein, W. T. Haskins, M. Landy, K. C. Milner, E. Ribi, and P. W. Stashak. Origin and properties of naturally occurring hapten from Escherichia coli. J. Bacteriol. 88:1705-1720. 1964.-Haptens found in preparations of endotoxin and in fractions of disrupted cells, particularly one termed "native hapten," which appeared to be associated with the protoplasm of cells rather than with cell walls, have been further investigated with a view to establishing their origin and composition as well as their host-reactive properties. For this purpose, cells from a smooth strain of Escherichia coli O111:B4 were either extracted directly or disrupted and separated into cell-wall and protoplasmic fractions. Haptens were obtained by gel filtration of endotoxins, by trichloroacetic acid extraction of protoplasm, and by a mild acid hydrolysis of endotoxin. Several lines of evidence indicated that native hapten originated in the protoplasm rather than by autolysis or degradation of cell-wall endotoxin during procedures employed in disruption. In gel diffusion and quantitative precipitin tests, no hapten was identical with endotoxin, but native hapten was serologically the most complex of the haptens and precipitated the most antibody. Native and acid haptens, on a weight basis, fixed about 1% of the quantity of complement fixed by homologous endotoxin. Haptens did not stimulate the production of antibodies in mice or rabbits and did not elicit endotoxic host reactions. Chemically, native hapten differed from endotoxin and from acid hapten in that it lacked phosphorus, heptose, long-chain fatty acids, and 2-keto-3-deoxyoctonate. These substances did not appear to be determinants of antigenic specificity, but they may provide necessary bonds for assembling hapten-like units into fully antigenic and toxic macromolecules.