Major Fatty Acid Constituents Research Articles

Flavobacterium lacicola sp. nov., isolated from a freshwater lake.

A bacterial strain, designated IMCC25901T, was isolated from a freshwater lake, Soyang, in the Republic of Korea. The strain was Gram-stain-negative, aerobic, non-motile, orange-coloured and short rod-shaped. The 16S rRNA gene sequence analysis showed that strain IMCC25901T was most closely related to Flavobacterium yonginense HMD1001T (97.0 %) and formed a robust phylogenetic clade with other species of the genus Flavobacterium. Growth of strain IMCC25901T was observed at 10-30 °C (optimum, 20 °C), pH 6-8 (optimum, pH 7) and 0-1.0 % NaCl (optimum, 0 %). The DNA G+C content of strain IMCC25901T was 34.2 mol%. The major fatty acid constituents of the strain were anteiso-C15 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and iso-C15 : 0. Cells of strain IMCC25901T contained phosphatidylethanolamine, an unidentified phospholipid, two unidentified aminolipids and two unidentified lipids. The isoprenoid quinone detected in the strain was MK-6. On the basis of the taxonomic data obtained in this study, it was concluded that strain IMCC25901T represented a novel species in the genus Flavobacterium, for which the name Flavobacterium lacicola sp. nov. is proposed. The type strain of Flavobacterium lacicola is IMCC25901T (=KCTC 52571T=NBRC 112883T).

Deinococcus lacus sp. nov., a gamma radiation-resistant bacterium isolated from an artificial freshwater pond.

A Gram-stain-negative, pink-coloured, non-motile and gamma radiation-resistant bacterium, designated strain IMCC1711T, was isolated from a freshwater sample collected from an artificial pond (Inkyong Pond). The 16S rRNA gene sequence analysis showed that strain IMCC1711T was most closely related to Deinococcus piscis 3axT (94.2 %) and formed a robust phylogenetic clade with other species of the genus Deinococcus. Optimal growth of strain MCC1711T was observed at 25 °C and pH 7.0 without NaCl. Strain IMCC1711T exhibited high resistance to gamma radiation. The DNA G+C content of strain IMCC1711T was 59.1 mol% and MK-8 was the predominant isoprenoid quinone. Major fatty acid constituents of the strain were C17 : 1ω8c, C16 : 0, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and C15 : 1ω6c. The major polar lipids constituted phosphatidylethanolamine, one unidentified phosphoglycolipid and two unidentified glycolipids. On the basis of taxonomic data obtained in this study, it was concluded that strain IMCC1711T represented a novel species of the genus Deinococcus, for which the name Deinococcus lacus sp. nov. is proposed. The type strain of Deinococcus lacus is IMCC1711T (KCTC 52494T=KACC 18979T=NBRC 112440T).

Biodegradation of alkali lignin by a newly isolated Rhodococcus pyridinivorans CCZU-B16.

Based on the Prussian blue spectrophotometric method, one high-throughput screening strategy for screening lignin-degrading microorganisms was built on 24-well plate at room temperature. One high activity of alkali lignin-degrading strain Rhodococcus pyridinivorans CCZU-B16 was isolated from soil. After the optimization of biodegradation, 30.2% of alkali lignin (4g/L) was degraded under the nitrogen-limited condition (30/1 of C/N ratio; g/g) at 30°C for 72h. It was found that syringyl (S) units and guaiacyl (G) in lignin decreased after biodegradation. Moreover, the accumulated lipid in cells had a fatty acid profile rich in C16 and C18 with four major constituent fatty acids including palmitic acid (C16:0; 22.4%), palmitoleic acid (C16:1; 21.1%), stearic acid (C18:0; 16.2%), and oleic acid (C18:1; 23.1%). In conclusion, Rhodococcus pyridinivorans CCZU-B16 showed high potential application in future.

Flavobacterium chuncheonense sp. nov. and Flavobacterium luteum sp. nov., isolated from a freshwater lake.

Two Gram-staining-negative, orange coloured, non-motile, rod-shaped bacterial strains, designated strains IMCC26013T and IMCC26026T, were isolated from a freshwater sample collected from Lake Soyang in Korea. The 16S rRNA gene-based phylogenetic analyses showed that both strains belonged to the genus Flavobacterium and that strains IMCC26013T and IMCC26026T were most closely related to Flavobacterium psychrophilum (96.5 %) and Flavobacterium myungsuense (97.7 %), respectively. DNA G+C contents of strains IMCC26013T and IMCC26026T were 37.8 and 33.7 mol%, respectively. DNA-DNA relatedness between strain IMCC26026T and F. myungsuense HMD1033T was 56.4 %, showing a novel species status of strain IMCC26026T. Major fatty acid constituents (>10 %) of strain IMCC26013T were iso-C15 : 1 G, C15 : 1 ω6c, C17 : 1 ω6c and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and those of strain IMCC26026T were iso-C15 : 0, anteiso-C15 : 0 and summed feature 3. Respiratory quinone detected in the two strains was MK-6. Both strains contained phosphatidylethanolamine as a major polar lipid. On the basis of these results, strains IMCC26013T and IMCC26026T were considered to represent novel species in the genus Flavobacterium, for which the names Flavobacterium chuncheonense (type strain IMCC26013T=KCTC 52573T=NBRC 112526T), and Flavobacterium luteum (type strain IMCC26026T=KCTC 52572T=NBRC 112527T) are proposed, respectively.

Predictive Skeletal Kinetic Model of Biodiesel Autoxidation

Gradual depletion of fossil fuels, growing environmental concerns, and global warming have shifted the focus to renewable liquid fuels, such as biodiesel. Biodiesel is reported to cause less emission and can be used in engines without much modification. Even though biodiesel fuels have promising combustion and emission characteristics for use in engines, their poor oxidation stability due to aging is an inhibiting factor for wider usage. In this paper, an autoxidation model for biodiesel fuels is proposed, considering their major fatty acid constituents. The proposed kinetic parameters are optimized using a genetic algorithm with the help of experimental data available in the literature. Temperature and fuel effects on the optimized rate parameters are studied. The proposed kinetics scheme is useful to predict the oxidation of fuel constituents with a fair degree of accuracy. The model also enables prediction of a useful engineering quantity, viz., induction period, to facilitate a priori evaluation of au...

Production of biodiesel from Amari (Amoora Wallichii King) tree seeds using optimum process parameters and its characterization

Amari (Amoora Wallichii King) is a forest based tree from Meliaceae family which is mainly used in making timber. Amari wood also possess some medicinal activity. In this article, biodiesel production from Amari tree seed oil (ATSO) was investigated. Oil content in the seed was 42.85%. Linoleic (32.938%) and oleic acids (23.007%) were the major fatty acid constituents in ATSO with 84.617% unsaturation. The free fatty acid (FFA) in ATSO was 16%, hence, a two stage acid base transesterification was done to produce biodiesel from ATSO. Effect of reaction time, temperature, methanol and catalyst concentrations on yields from the 1st stage acid pre-treatment and 2nd stage base transesterification was evaluated. Maximum 96% yield (vol.%) from the 1st stage occurred with 0.80% (v/v) H2SO4 at an oil methanol ratio of 4:1 after 3.5h of acid esterification. From the 2nd stage, highest biodiesel yield of 88.5% (vol.%) was obtained during base catalysed transesterification by adding 1% (w/v) NaOH and 30% (v/v) methanol with the acid pre-treated oil after 2.5h. Characterization of ATSO fatty acid methyl ester (FAME) was done and properties were compared with Amoora and Pithraj tree seed biodiesels from same Meliaceae family. Properties were found similar and most of them conformed to the ASTM D6751 and EN 14214 standards except water and sulphur contents with slight deviations.

Environmental alterations in biofuel generating molecules in Zilla spinosa.

Now days, production of fuels and petrochemicals from renewable lignocellulosic biomass is an indispensable issue to meet the growing energy demand. Meanwhile, the changes in the climate and soil topography influence the growth and development as well as canopy level of the lignocellulosic biomass. In this study, Zilla spinosa Turr (Zilla) plants with similar age and size were collected from three main sectors (upstream, midstream, and downstream) of Wadi Hagul during spring (April) and summer (July) seasons. Environmental stresses evoked reduction in the energy trapping pigments concomitant with increments in chlorophyll fluorescence in summer harvested plants particularly at downstream. Furthermore, the biofuels generating compounds including carbohydrate, lignin, and lipid making the plant biomasses are greatly affected by environmental conditions. Greater amount of lignin was estimated in summer harvested Z. spinosa shoots particularly at downstream. Moreover, the total oil content which is a promising source of biodiesel was considerably decreased during summer season particularly at downstream. The physical properties of the lipids major constituent fatty acid methyl esters determine the biofuel properties and contribute in the adaptation of plants against environmental stresses. Hence, the analysis of fatty acid profile showed significant modifications under combined drought and heat stress displayed in the summer season. The maximum increase in saturated fatty acid levels including tridecanoic acid (C13:0), pentadeanoic acid (C15:0), palmitic acid (C16:0), and stearic acid (C18:0) were estimated in spring harvested Z. spinosa aerial portions particularly at midstream. In spite of the reduction in the total oil content, a marked increase in the value of unsaturated to saturated fatty acids ratio and thereby the unsaturation index were achieved during the dry summer period. Henceforth, these seasonal and spatial variations in fatty acids profiles may contribute in the acclimatization of Z. spinosa plants to soil water scarcity associated with heat stress experienced during summer. In addition, the alterations in the fatty acid profiles may match biofuel requirements. In conclusion, the most adequate growing season (spring) will be decisive for achieving high lipid productivity associated with improved biofuel quality in terms of high saturated fatty acids percentage that improves its cetane number. However, the dry summer season enhanced the accumulation of greater amount of lignin that may enhance the biodiesel quantity.

Simultaneous Enzyme/Whole-Cell Biotransformation of Plant Oils into C9 Carboxylic Acids

Oxyfunctionalization of plant oils such as olive oil and soybean oil into C9 carboxylic acids (e.g., n-nonanoic acid and 9-hydroxynonanoic acid) was investigated. The biotransformation was composed of hydrolysis of plant oils by the Thermomyces lanuginosus lipase (TLL) and C9–C10 double-bond cleavage in unsaturated fatty acids by a serial reaction of a fatty acid double bond-hydratase of Stenotrophomonas maltophilia, an alcohol dehydrogenase of Micrococcus luteus, and a Baeyer–Villiger monooxygenase (BVMO) of Pseudomonas putida KT2440 expressed in Escherichia coli. The newly cloned oleate hydratase allowed one to produce 10-hydroxyoctadecanoic acid and 10-hydroxyoctadec-12-enoic acid at a high rate from oleic acid and linoleic acid, respectively, which are major fatty acid constituents of many plant oils. Furthermore, overexpression of a long chain fatty acid transporter FadL in the recombinant E. coli led to a significant increase of whole-cell biotransformation rates of oleic acid and linoleic acid into...

Comparative Studies on Egyptian and Libyan Roselle Seeds as a Source of Lipid and Protein

Proceeding from the fact that the seeds of Roselle plant are full of nutritional constituents, however in Egypt and Libya, they are often discarded as a by-product, this study aims to evaluate the nutritional composition of Roselle seeds grown in Egypt and Libya as a source of oil and protein besides making a comparison between whole chemical composition of Roselle seeds grown in both countries. Ground of whole Egyptian and Libyan Roselle seeds powder contained high amount of protein (31.02% ± 0.93% and 28.67% ± 0.45%), crude fat (21.6% ± 0.66% and 16.94% ± 0.86%) and total ash (6.89% ± 0.11% and 5.60% ± 0.10%), respectively. However, Egyptian seeds have moisture content, protein, crude fat and total ash higher than Libyan seeds. Crude oil from Egyptian seeds had high refractive index and iodine value in comparison with crude oil from Libyan seeds. There were no remarkable differences between both seeds in acidity percent, unsaponifiable matters percent and saponification value. Linoleic, oleic and palmitic acids were the major fatty acid constituents in Egyptian Roselle seeds. Meanwhile linolenic, linoleic, oleic, stearic, palmitoleic and palmitic acids were the major fatty acid constituents in Libyan Roselle seeds. Crude oil from Egyptian seeds had higher percent of unsaturated fatty acids than crude oil from Libyan seeds. Unsaponifiable matters constituents for extracted oil from Egyptian seeds were free from n-pentacosane (C25) and rich in n-hexacosane (C26). Oil from both seeds had the same content of Beta sito-sterol and stigma-sterol. Both seeds were rich in glutamic acid, aspartic acid, arginine and leucine. Libyan seeds were rich in essential amino acids in comparison with Egyptian seeds. Finally nutritional comparison of Roselle seeds variation depends on the variety, location and environmental conditions during cultivation. Roselle seeds are a good source for extraction of oil and protein. Protein from Roselle seeds could be used as a supplement material for poor food in lysine.

Flavobacterium spartansii sp. nov., a pathogen of fishes, and emended descriptions of Flavobacterium aquidurense and Flavobacterium araucananum

Two strains (T16(T) and S12) of a Gram-reaction-negative, rod-shaped, yellow-pigmented bacterium were recovered from kidneys of feral spawning adult Chinook salmon (Oncorhynchus tshawytscha) and the gills of captive-reared Chinook salmon fingerlings suffering a mortality episode, respectively. Polyphasic characterization revealed that these strains possessed gliding motility, contained a flexirubin-type pigment, proteolysed multiple substrates (i.e. gelatin, casein and elastin), and had a mean DNA G+C content of 35.6 mol%. Sequencing of the 16S rRNA gene demonstrated that strains T16(T) and S12 were nearly identical to one another (>99% similarity) and were placed within the genus Flavobacterium, with Flavobacterium aquidurense CCUG 59847(T) (98.3%), Flavobaterium araucananum CCUG 61031(T) (98.2%) and Flavobacterium frigidimaris (AB183888, 98.1%) being their closest relatives. Subsequent phylogenetic analyses using neighbour-joining, maximum-parsimony and Bayesian methodologies demonstrated that strains T16(T) and S12 formed a well-supported clade within the genus Flavobacterium that was distinct from other Flavobacterium species. The major fatty acid constituents of strains T16(T) and S12 were iso-C15 : 0, C16 : 1ω6c and/or C16 : 1ω7c, iso-C17 : 0 3-OH, and iso-C15 : 0 3-OH according to fatty acid methyl ester analysis. The mean level of DNA-DNA relatedness between strain T16(T) and F. aquidurense CCUG 59847(T) and F. araucananum CCUG 61031(T) was 23 and 29%, respectively. Thus, the data accumulated in this study support the suggestion that strains T16(T) and S12 represent a novel species of the genus Flavobacterium, for which the name Flavobacterium spartansii sp. nov. is proposed. The type strain is T16(T) ( = LMG 27337(T) = ATCC BAA-2541(T)). Emended descriptions of F. aquidurense and F. araucananum are also proposed.

Mushroom tyrosinase inhibitory activity and major fatty acid constituents of Amazonian native flora oils

In order to treat hyperpigmentation-related problems, there has been a global trend in developing cosmetics claiming to have skin-whitening properties, which act by inhibiting melanin biosynthesis. The objective of this work was to evaluate the in vitro mushroom tyrosinase inhibitory activity of five Amazonian native flora oils, and so to verify the possibility of their incorporation into cosmetic products. In addition, the fatty acid composition of the essential oils was determined by gas chromatography-flame ionisation detection in order to determine the main components of these oils. The tyrosinase inhibitory activity of the tested oils was found to be in the following order: açaí (IA50 = 66.08 µg mL-1) > tucumã > patauá > pracaxi > castanha do Brasil. This study suggests that açaí oil has great potential in the treatment of hyperpigmentation and other related disorders, due to its considerable tyrosinase inhibitory activity.

Effect of boiling on the physicochemical properties of Roselle seeds (Hibiscus sabdariffa L.) cultivated in Mali

Mali was shown. Proximate analysis indicated that boiled whole Roselle seeds (BWRS) are potential high protein source. Moreover, the results of lipid analysis indicated that the seeds were good source of unsaturated fatty acid (74.33%) with that of linoleic (35.55%), oleic (36.64%), palmitic (19.34%) and stearic acid (4.86%) being the major fatty acid constituents. The most predominant inorganic elements were found to be potassium, followed by magnesium and calcium. Aluminum and phosphorus were relatively low in both BWRS and un-boiled whole Roselle seeds (WRS). Roselle seeds exhibited various molecular weight distributions as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Scanning electron microscopic (SEM) analysis revealed that boiling had little influence on the physical particles size. In addition, Roselle seed powder meals maintained excellent protein, lipid and minerals compositions, following boiling with protein quality of powders prepared from whole and boiled seeds being similar.

English

Microbial lipid was produced by the soil isolated oleaginous yeast Torulaspora maleeae Y30 using glucose in flask-batch fermentation. At low concentration of nitrogen, maximum lipid production rate was observed; while high nitrogen concentration (0.4 g/l) resulted in high volumetric cell mass production rate (0.960 g/l d) and specific growth rate (0.266 d -1 ). The isolated yeast T. maleeae Y30 had maximum values of 0.382 g/l d, 0.507 g lipid/g cells, 3.06 g/l and 0.105 g/L d for volumetric lipid production rate, specific yield of lipid, lipid concentration and specific rate of lipid production, respectively when culture was performed in nitrogen-limiting medium supplemented with 90 g/l glucose and 0.2 g/l (NH 4)2SO 4. The Monod’s constant ( KS, g/l) and µmax (1/d) of 24.52 and 0.156, were obtained, respectively. The three major constituent fatty acids of the isolated yeast T. maleeae Y30 were palmitic acid, stearic acid and oleic acid that are comparable to vegetable oils, suggesting that, microbial lipid from these yeast can be used as potential feedstock for biodiesel production.

Comparison of nutrient composition in kernel of tenera and clonal materials of oil palm (Elaeis guineensis Jacq.)

Nutritive information about oil palm kernel is scarce, especially on the composition of sugars and water-soluble vitamins. This study aims to evaluate both tenera and clonal materials for their proximate composition, fatty acid profile, amino acid composition, sugar, mineral and water-soluble vitamin contents. The tenera material had a higher moisture, fat and fibre content as compared to the clonal material, whereas protein, carbohydrate and ash content were higher in the clonal material. The major fatty acid constituents in palm kernel oil were lauric acid, myristic acid and oleic acid. The palm kernel proteins were deficient in lysine and tryptophan but rich in glutamic acid, arginine and aspartic acid. Sucrose was the most abundant sugar in palm kernel. The mineral analysis of the samples showed high levels of potassium, phosphorus, magnesium, calcium and manganese, while niacin was the water-soluble vitamin present at the highest concentrations in palm kernel.

Lipid classes of in vitro cultivar of Pakistani citrus

The in vitro cultivar of citrus contained 18.0% lipids after 12weeks of germination of seed. The lipid was analyzed by GC procedure for its fatty acid composition. The oil contained seven major fatty acid constituents which were later identified by GC. The oil was further analyzed for its classes by means of thin layer chromatography and gas chromatography. The major portion of the lipid classes comprised of neutral lipids (93.9%) and polar lipids (6.1%). The identified neutral lipids comprised of hydrocarbon (1.4%), wax esters (1.5%), sterol esters (5.2%), triglycerides (52.3%), free fatty acids (1.3%), 1,3-diglycerides (6.0%), 1,2-diglycerides (5.0%), glycol (15.2%), sterols (6.0%), 2-monoglycerides (6.4%), 1-monoglycerides (5.3%) and the identified polar lipids comprised of phosphatidyl ethanolamine (1.8%) phosphatidyl choline (0.9%) lysophosphatidyl ethanolamine (1.8%) and phosphatidyl inositol (1.1%).

Howardella ureilytica gen. nov., sp. nov., a Gram-positive, coccoid-shaped bacterium from a sheep rumen

An unidentified obligately anaerobic, fastidious, Gram-positive, non-motile, non-spore-forming, non-fermentative coccoid-shaped bacterium (designated strain GPC 589(T)) was isolated from the rumen fluid of a sheep. The major fatty acid constituents (>5 %) were C(16 : 0) (29.2 %), C(18 : 0) (40.7 %) and an unidentified compound (19.7 %) with an equivalent chain-length of 13.523. The G+C content of the DNA was 34 mol%. The organism was strongly ureolytic and generated ATP through the hydrolysis of urea. Comparative 16S rRNA gene sequence analysis demonstrated that strain GPC 589(T) was far removed, phylogenetically, from the ruminococci and related Gram-positive anaerobic cocci but exhibited a phylogenetic association with Clostridium rRNA cluster XIVa [as defined by Collins, M. D., Lawson, P. A., Willems, A., Cordoba, J. J., Fernandez-Garayzabal, J., Garcia, P., Cai, J., Hippe, H. & Farrow, J. A. E. (1994). Int J Syst Bacteriol 44, 812-826]. Sequence divergence values of 12.5 % or more were observed between strain GPC 589(T) and all other recognized species within this and related rRNA clostridial clusters. Phylogenetic analysis showed that strain GPC 589(T) represents a new genus within cluster XIVa. On the basis of both phylogenetic and phenotypic evidence, it is proposed that strain GPC 589(T) should be classified as representing a new genus and novel species, Howardella ureilytica gen. nov., sp. nov. The type strain is strain GPC 589(T) (=DSM 15118(T)=JCM 13267(T)).

High-density cultivation of oleaginous yeast Rhodosporidium toruloides Y4 in fed-batch culture

Microbial lipid production by the oleaginous yeast Rhorosporidium toruloides Y4 was studied using glucose as carbon source, in order to realize high-density cell culture. Batch cultures demonstrated that there was little inhibitory effect with a substrate concentration of up to 150 g l −1. Flask fed-batch cultures were run for 25 days and reached a dry biomass and cellular lipid content of 151.5 g l −1 and 48.0% (w/w), respectively. Using pilot-scale fed-batch cultures in a 15-l stirred-tank fermenter for 134 h resulted in dry biomass, lipid content and lipid productivity of 106.5 g l −1, 67.5% (w/w) and 0.54 g l −1 h −1, respectively. The fed-batch culture model used here featured initial nutrient-rich media and a pure carbon source with discontinuous feeding. Gas chromatography analysis revealed that lipids from R. toruloides Y4 contained mainly long-chain fatty acids with 16 and 18 carbon atoms. The four major constituent fatty acids were oleic acid, palmitic acid, stearic acid and linoleic acid. A slight increase in stearic acid production was found during the culture process. Based on these compositional data, microbial lipids from R. toruloides Y4 are a potential alternative oil resource for biodiesel production.

Anti-Aromatase Activity of Phytochemicals in White Button Mushrooms (Agaricus bisporus)

White button mushrooms (Agaricus bisporous) are a potential breast cancer chemopreventive agent, as they suppress aromatase activity and estrogen biosynthesis. Therefore, we evaluated the activity of mushroom extracts in the estrogen receptor-positive/aromatase-positive MCF-7aro cell line in vitro and in vivo. Mushroom extract decreased testosterone-induced cell proliferation in MCF-7aro cells but had no effect on MCF-10A, a nontumorigenic cell line. Most potent mushroom chemicals are soluble in ethyl acetate. The major active compounds found in the ethyl acetate fraction are unsaturated fatty acids such as linoleic acid, linolenic acid, and conjugated linoleic acid. The interaction of linoleic acid and conjugated linoleic acid with aromatase mutants expressed in Chinese hamster ovary cells showed that these fatty acids inhibit aromatase with similar potency and that mutations at the active site regions affect its interaction with these two fatty acids. Whereas these results suggest that these two compounds bind to the active site of aromatase, the inhibition kinetic analysis indicates that they are noncompetitive inhibitors with respect to androstenedione. Because only conjugated linoleic acid was found to inhibit the testosterone-dependent proliferation of MCF-7aro cells, the physiologically relevant aromatase inhibitors in mushrooms are most likely conjugated linoleic acid and its derivatives. The in vivo action of mushroom chemicals was shown using nude mice injected with MCF-7aro cells. The studies showed that mushroom extract decreased both tumor cell proliferation and tumor weight with no effect on rate of apoptosis. Therefore, our studies illustrate the anticancer activity in vitro and in vivo of mushroom extract and its major fatty acid constituents.

Physical and chemical properties associated with food quality in sorghum

Samples of 13 genetically diverse sorghum [Sorghum bicolor (L.) Moench] accessions were analysed for physical properties and chemical composition. The food (injera) quality and the phenolic (condensed tannins) content of six sorghum samples were also determined. The accessions showed a wide variation in protein (7.99 to 17.8%), lipids (2.52 to 4.76%), starch (51.88 to 85%), and amylose (12.30 to 28.38%) content. Grain weight varied in a wide range, and endosperm texture varied from intermediate to completely starchy. Linoleic acid (18:2) and oleic acid (18:1) were the major fatty acid constituents of sorghum lipids. Only a few significant correlations were observed among the physical and chemical properties. Three of the six accessions used for sensory analysis, namely Ambajeettee, AL-70 and ETS 2752 were chosen for their desirable properties in injera making. The chemical and physical properties of the selected accessions were characterised by high protein content, low tannins, intermediate endosperm texture, and white seed colours. Red seeded sorghum and white seeded sorghum with pigmented testa were found to be less desired.

Characterization of triacylglycerols from overwintering prepupae of the alfalfa pollinator Megachile rotundata (Hymenoptera: Megachilidae).

Alfalfa leafcutting bees, Megachile rotundata (F.), overwinter as prepupae. The internal lipids were extracted from prepupae that had been wintered at 4 degrees C for 7 months. Megachile rotundata prepupae possessed copious quantities of internal lipids (20% of the fresh weight) that were extracted with CHCl3/methanol (2:1). Transmission electron microscopy revealed that lipids were stored within very large intracellular vacuoles. Separation by silica chromatography revealed that 88% of the internal lipids were triacylglycerols. Ester derivatives of fatty acids from triacylglycerol components were analyzed by gas chromatography-mass spectrometry and 15 fatty acid constituents were identified. The majority (76%) of the triacylglycerol fatty acids were unsaturated fatty acids. The major triacylglycerol fatty acid constituent (30%) was the C16 monounsaturated fatty acid, palmitoleic acid (16:1, hexadec-9-enoic acid), with substantial amounts of linolenic acid (18:3, octadec-9,12,15-trienoic acid, 15%), palmitic acid (16:0, hexadecanoic acid, 14%) and oleic acid (18:1, octadec-9-enoic acid, 13%). Palmitoleic acid as the major fatty acid of an insect is an unusual occurrence as well as the presence of the 16-carbon polyunsaturated fatty acids, 16:2 and 16:3. The major intact triacylglycerol components were separated and identified by high performance liquid chromatography-mass spectrometry. A complex mixture of approximately 40 triacylglycerol components were identified and major components included palmitoyl palmitoleoyl oleoyl glycerol, palmitoyl palmitoleoyl palmitoleoyl glycerol, myristoyl palmitoleoyl palmitoleoyl glycerol, myristoleoyl palmitoyl palmitoleoyl glycerol, and palmitoyl palmitoleoyl linolenoyl glycerol. The function of these internal lipids and their relevance to winter survival and post-wintering development of M. rotundata is discussed.