Rapid and sensitive assay for free fatty acids using rhodamine 6G

Anderson, Mark M.; McCarty, Richard E.

doi:10.1016/0003-2697(72)90026-7

Cited by 54 publications

(10 citation statements)

References 11 publications

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“…The reaction medium was acidified with 0.13 N HC1 and extracted with toluene. The colorimetric procedures of Lamberet et al (1982) and of Anderson and McCarty (1972) were used for determination of the methyl ketone and fatty acid content of the organic layer .…”

Section: Methodsmentioning

confidence: 99%

A fed-batch technique for 2-heptanone production by spores of Penicillium roquefortii

Creuly

Larroche

Gros

1990

Appl Microbiol Biotechnol

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A fed-batch technique for the production of 2-heptanone from octanoic acid by Ca-alginate/Eudragit RL-entrapped spores of Penicillium roquefortii is presented. It involves the use of a pH-stat apparatus, the increase in pH arising due to the reaction being overcome by direct substrate addition. When the reaction is performed at pH 5.5, no true constant rate period can be achieved due to a gradual buffering of the medium connected with a decrease in the catalytic activity of the spores. At pH 6.5 the system exhibits high stability and the reaction rate remains constant for at least 300 h with a value of 0.975 m M / h and a substrate concentration close to 4 mM. The process used may be very useful in the study of long-term behaviour of biocatalysts when the medium is not renewed and when the reaction involves an ionic compound and a neutral one.

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Section: Methodsmentioning

confidence: 99%

A fed-batch technique for 2-heptanone production by spores of Penicillium roquefortii

Creuly

Larroche

Gros

1990

Appl Microbiol Biotechnol

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“…Liberated free fatty acid was extracted with 5 mL ether. The ether layer was evaporated to dryness and was assayed colorimetrically with Rhodamine 6G (12). One unit of lipase activity is defined as 1 µmol fatty acid liberated/min at 40°C.…”

Section: Microorganismsmentioning

confidence: 99%

Characterization of new yeast lipases

Hou

1997

J Americ Oil Chem Soc

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Previously, we used a simple, sensitive agar plate method to screen lipase activity from 1229 selected cultures, including 508 bacteria, 479 yeasts, 230 actinomycetes and 12 fungi, that covered many genera and species. About 25% of the cultures tested were lipase-positive. We also expanded our screening method to focus specifically on the pH dependence and thermostability of these lipase activities. In this report, we have characterized 25 yeast lipases, obtained from our screening program, on the basis of their positional specificity against triglycerides. Lipase was produced by growing cultures on nutrient medium in the presence of vegetable oil at 25°C for 4 d. Of the 25 new yeast lipases analyzed, 19 showed 1,3-positional specificity and 6 showed random specificity. No 2-positional specific lipases were found. Among those cultures with highest lipase activity are: Candida silvicola NRRL YB-2846 (random); Candida sp. 55 (random); Candida sp. 125 (random); Pichia americana NRRL Y-2156 (1,3-specific); P. muscicola NRRL Y-7005 (random); P. petersanii NRRL YB-3808 (1,3-specific); and Yarrowia lipolytica NRRL YB-423 (random). Characterization of Candida sp. strain 55 lipase on its substrate preference showed that this enzyme hydrolyzed soybean oil triglyceride species LLLn, LLL, LLO, and LLP more readily than LOO, LOP, OOO, LOS, and POO, where L = linoleic, Ln = linolenic, O = oleic, P = palmitic, and S = stearin. JAOCS 74, 1391-1394 (1997).

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“…Chl (4) and protein (26) were assayed spectrophotometrically. Fatty acids were estimated according to Anderson and McCarty (2). Electron transport was assayed at pH 8 (1).…”

Section: Methodsmentioning

confidence: 99%

“…The combined petroleum ether phases were washed three times with 3 ml of H20 to remove HCI. Aliquots of the petroleum ether phases were evaporated to dryness, and the fatty acid content was estimated (2).…”

Section: Methodsmentioning

confidence: 99%

Role of Galactolipids in Spinach Chloroplast Lamellar Membranes

Shaw¹,

Anderson²,

McCarty³

1976

Plant Physiol.

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A galactolipid lipase from primary bean (Phaseolus vulgaris) leaves has been used to partially deplete spinach chloroplast inner membranes of their galactolipids. Chloroplasts treated with the lipase in the absence of bovine serum albumin lost 91% of their monogalactosyl diglyceride, 83% of their digalactosyl diglyceride, all of their phosphatidyl choline, but none of their sulfolipid. Electron microscopy of thin sections revealed that the treated chloroplasts were greatly enlarged and lacked membrane stacking. Linolenic acid had similar effects on the structure of the chloroplasts. Chlorophyll, carotenoids, and coupling factor 1 remained bound to the treated membranes.To minimize the inhibition of phosphorylation and electron flow by fatty acids released by the lipase, bovine serum albumin (15-24 mg/ml) was added to the lipase incubation mixtures. Bovine serum albumin inhibited the extent, but not the initial rate, of fatty acid release by the lipase. Electron microscopy of chloroplasts treated with the lipase in the presence of bovine serum albumin showed that membrane stacking was partially maintained. Chloroplasts treated with lipase under these conditions retained about 30% of their monogalactosyl diglyceride, 50% of their digalactosyl diglyceride and phosphatidyl choline. The sulfolipid and phosphatidyl glycerol contents were unchanged. Electron flow through photosystems I and II with artificial electron donors and acceptors was not affected by lipase treatment in the presence of bovine serum albumin. In contrast, oxygen evolution and phosphorylation were partiadly inhibited. These reactions are also very sensitive to fatty acids and it is possible that the inhibition is the result of interaction of fatty acids with the membrane prior to their binding to bovine serum albumin.In view of the irreversible inactivation of electron flow and phosphorylation by fatty acids, it is difficult to assess the role of galactolipids in these processes when a specfic lipase is used to deplete the membrane.Galactosyl diglycerides are present in high concentrations in the photosynthetic membranes of higher plants and algae,

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Rapid and sensitive assay for free fatty acids using rhodamine 6G

Cited by 54 publications

References 11 publications

A fed-batch technique for 2-heptanone production by spores of Penicillium roquefortii

A fed-batch technique for 2-heptanone production by spores of Penicillium roquefortii

Characterization of new yeast lipases

Role of Galactolipids in Spinach Chloroplast Lamellar Membranes

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