Selection of Schizochytrium limacinum mutants based on butanol tolerance

Background: Mutation breeding is one of the most important routes to achieving high docosahexaenoic acid (DHA) productivity using Schizochytrium. However, few selection strategies have been reported that aim to generate a high DHA content in Schizochytrium lipids. Results: First, culture temperature altered the butanol tolerance of Schizochytrium limacinum B4D1. Second, S. limacinum E8 was obtained by selecting mutants with high butanol tolerance. This mutant exhibited a 17.97% lower proportion of DHA than the parent strain S. limacinum B4D1. Third, a negative selection strategy was designed in which S. limacinum F6, a mutant with poor butanol tolerance, was obtained. The proportion of DHA in S. limacinum F6 was 11.22% higher than that of parent strain S. limacinum B4D1. Finally, the performances of S. limacinum B4D1, E8 and F6 were compared. These three strains had different fatty acid profiles, but there was no statistical difference in their biomasses and lipid yields. Conclusion: It was feasible to identified the relative DHA content of S. limacinum mutants based on their butanol tolerance.

Protective effect of eicosapentaenoic acid-docosahexaenoic acid and α–linolenic acid rich phytosterol ester on brain antioxidant status and brain lipid composition in hypercholesterolemic rats.

With a view to investigate the ameliorative effects of sitosterol esters against degenerative effects of hypercholesterolemia brain antioxidant enzyme assays, brain lipid profile, brain phospholipid compositional change and brain neurotransmitter concentrates (glutamic acid, asparctic acid, glycine) were measured in hypercholesterolemic rats. The results indicated that phytosterol esters have a role in countering hypercholesterolemia-related changes in the brain by decreasing the cholesterol levels, increasing the phospholipid levels and increasing the level of antioxidant enzymes. The results suggest that phytosterol esters may be of therapeutic significance and may offer new and effective options for the treatment of hypercholesterolemia-induced changes in the brain.

Correlation between the eicosapentaenoic acid, docosahexaenoic acid and the aggressive behavior in mice / 法医学杂志

OBJECTIVE@#To explore the correlation between the eicosapentaenoic acid(EPA), docosahexaenoic acid (DHA) and the aggressive behavior in mice.@*METHODS@#Seventy-two male Kunming mice were divided into control group, fish oil group, simvastatin group and aggressive reference group randomly. The control group, fish oil group and simvastatin group were given normal saline, fish oil and simvastatin by irrigation respectively for 3 months consecutively, each mouse was raised isolatedly. The latent period of assault, the frequencies of tail swing and assault, and the cumulative time of assault were recorded at the beginning and the end of the intervention. Finally, the EPA and DHA in brain were analyzed by gas chromatography-mass spectrometry (GC-MS). The aggressive reference group was raised without intervention and was evaluated as aggressive reference only.@*RESULTS@#(1) Before intervention, the latent period of assault, the frequencies of tail swing, the frequencies of assault, and the cumulative time of assault were not significantly different from each other group. After intervention, the differences were significant (P<0.05). (2) After the intervention, the content of EPA and DHA in mice brain was the most in the fish oil group, and the least in the simvastatin group. (3) The content of EPA was negatively related with the four indexes (P<0.05) before and after the intervention. The content of DHA was negatively related with the frequencies of tail swing and assault (P<0.05).@*CONCLUSION@#There is a correlation between the EPA, DHA and aggressive behavior in mice under stress.

Incorporacion de acidos grasos de aceite de calamar a lipoproteinas plasmaticas en ratas / Incorporation of squid oil fatty acids to plasma lipoproteins in rats

Se estudió la absorción e incorporación de ácidos grasos poliinsaturados de cadena larga de la serie n-3 (AGPI n-3) a lipoproteínas plasmáticas de ratas. Se suplementó la dieta de 2 grupos de 7 ratas durante 28 días con aceite de calamar (Ac) n=7 o con ácidos grasos libres de aceite de calamar (AGL) n=7. Ambos preparados tenían igual composición de ácidos grasos y 13,6% de elcosapentanoico, EPA 20:5 n-3 y 17.7% de docosahexaenoico, DHA 22:6 n-3. El grupo Ac ingirió 80 mg/día de AGPI n-3 el AGL 90 mg/día. Se verificó un similar incremento del EPA y DHA plasmáticos en ambos grupos (p < 0,01), descenso del ácido araquidónico, AA 20Ñ4 n-6 (Acp < y AGL p < 0,02) e incremento del linoleico, LA 18:2 n-6 (Ac p<0,01 y AGL p<0,02) y en menor grado del dihomogammalinolénico, DHGLA 20:3 N-6 (Ac p<0,05). Las modificaciones del AA, LA y DHGLA se deberían al efecto inhibidor de los AGPI n-3 sobre las d 6 y d 5 desaturasas, que produce disminución de la síntesis endógena de AA y acumulación de sus respectivos sustratos (LA y DHGLA). A pesar de que el aporte de DHA fue mayor que el de EPA el incremento porcentual del EPA fue mayor, lo que se debería a la retroconvensión del DHA. No se verificó modificación en los niveles de ácidos grasos no esteritificados, colesterol y triglicéridos plasmáticos ni en la seudocolinesterasa, alanino-amino-transferasa y aspartato-amino transferasa séricas. Se concluyó que la absorción intestinal de AGPI n-3 como AGL es equivalente a la de los aportados como triglicéridos