ABSTRACT
Based on previous bioinformational analysis results, two Aspergillus niger lipase (ANL) mutants, ANL-Ser84Gly and ANL-Asp99Pro were constructed to screen ANL mutants with oil-water interface independence. ANL-Ser84Gly still displayed a pronounced interfacial activation, while ANL-Asp99Pro displayed no interfacial activation. The specific activity of ANL-Ser84Gly towards p-nitrophenyl palmitate (-myristate, -laurate and -decanoate) decreased by 29.8% (53.1, 60.1 and 77.1, respectively) than that of ANL, while the specific activity of ANL-Asp99Pro towards p-nitrophenyl palmitate increased by 2.2-fold. The mutation in the hinge region at both sides of the lid domain also destabilized various secondary structure factors of ANL-S84G and ANL-D99P, which resulted in a substantial decrease in thermostability. The achievement to construct oil-water interface-independent ANL mutants would help to further understand lipase interfacial activation mechanism.
Subject(s)
Aspergillus niger , Genetics , Base Sequence , Enzyme Stability , Fungal Proteins , Genetics , Metabolism , Lipase , Genetics , Metabolism , Molecular Sequence Data , Mutant Proteins , Genetics , Oils , Substrate Specificity , WaterABSTRACT
Object To study the amount and properties of glycopeptide of Ganoderma lucidum (Leyss ex Fr ) Kaist. cultivated with grass (GLPG) and wood log (GLPW) ; to investigate the feasibility of substitution of grass for wood log to cultivate G lucidum Methods Glycopeptides were extracted and isolated from the fruit body of G lucidum followed by dialysis; the monosaccharid constituent and relative molecular weight of polysaccharides were examined by GC and gel filtration; structure of glycopeptide was determined by IR, 1H NMR and 13 C NMR Results Relative molecular weights of GLPW and GLPG glycopeptides were (Mw) 5 13?10 5 and 5 85?10 5, (M?) 6 21?10 5 and 6 96?10 5, respectively; the glucosidic bonds of both glycopeptides were ? type; both glycopeptides consist 16 amino acids and Rha, Xyl, Fru, Gal and Glc (there was trace amount of Man in GLPW) Conclusion There are less physical and chemical difference between GLPG and GLPW The purification rate of GLPG is 2 8 times to GLPW
ABSTRACT
The main nutrient compositions of dry Porphyra haitanensis cultivated in Lianjiang,Fujian Province were analyzed: the total amino acids content was 35.48%. The scores of amino acids were 71 for Ile and 80 for Leu. Crude fatty acids was as low as 0. 5%,in which EPA took 24.8%. Minerals in Porphyra haitanensis were abundant. The content of Ca、Fe、 Zn、Mg were 3. 63、0. 56、0. 095 and 3. 29mg?g～-1. The results indicated that Porphyra haitanensis is a kind of health food with high nutrition.
ABSTRACT
Objective: 1.To analyze the nutritional composition and evaluation of the nutritional value of Mortierella isabelina powder. 2.To investigate the effects of Mortierella isabelina powder on prevention and regulation of hyperlipidemia in rats. Methods: 1. Mycelium powder was analyzed for proteins, lipids polysaccharides, fibre, ash, vitamin E, amino acids, fatty acids and minerals. 2. Mycelium powder was used to feed rats in different dosages together with high lipid diet for 10 days. 3. Mycelium powder was used to feed hyperlipidemic rats in different dosages for 30 days. Results: (1) There were about 20% of proteins and more than 50% of lipids in the mycelium. Further examination found that the mycelium contained rich essential amino acids and unsaturated fatty acids. The mycelium also contained vitamin E and useful minerals such as K, Ca, P, Fe, Zn and Mn. (2) 0.6 or 1.2 g/(kg?d) dosage of mycelium powder could prevent the rise of serum lipids. (3) When the mycelium powder was used to feed hyperlipidemic rats, the serum cholesterol, triglyceride, LDL C and VLDL C of the rats could be reduced, meanwhile HDL C could be increased. Conclusion: The results indicated that Mortierella isabelina powder has potential nutritional value and can be used to regulate the blood lipids in hyperlipidemic rats.