Purification and characterisation of an alkaliphilic esterase from a culinary medicinal mushroom, Sparassis crispa

Medicinal, nutritional, and nutraceutical potential of Sparassis crispa s. lat.: a review

Sparassis crispa is an edible mushroom exhibiting a wide range of medicinal properties. It is recognized for therapeutic value because of the high β-glucan content in the basidiomes. The broad range of its reported curative effects include anti-tumour, anti-cancer, immune-enhancing, hematopoietic, anti-angiogenic, anti-inflammatory, anti-diabetic, wound-healing, antioxidant, anti-coagulant, and anti-hypertensive properties. However, most of the studies are conducted on immunomodulatory and anticancer activities. Besides this, it also exhibits anti-microbial properties due to the presence of sparassol. Technology is now available for the cultivation of S. crispa on coniferous sawdust. This review is an attempt to focus on its distribution, taxonomy, chemical composition, medicinal properties, potential applications, and artificial cultivation.

GC-MS based metabolomics study of fermented stipe of Sparassis crispa

GC-MS coupled with multivariate statistical analysis was performed to understand metabolites difference between pileus and stipe of Sparassis crispa (cauliflower mushroom). Metabolic changes of S. crispa after fermentation by different microorganisms were also investigated. PCA score plot showed a clear separation between pileus and stipe of S. crispa regardless of fermentation. However, OPLS-DA score plot showed clear separation among fermented S. crispa samples according to microbial strain used, indicating that both pileus and stipe fermented with the same strain showed similar pattern of metabolites. Fructose, lactic acid, citric acid, malic acid, and phosphoric acid were metabolites that contributed to the discrimination of fermented S. crispa samples. Results of this study provide novel insights into intrinsic characteristics of stipe of S. crispa which is cheaper than pileus as ingredient for alternative functional food.

Feruloyl esterase from the edible mushroom Panus giganteus: a potential dietary supplement

A novel 61 kDa feruloyl esterase (FAE) was purified to homogeneity from freshly collected fruiting bodies of Panus giganteus. The isolation procedure involved chromatography on the ion exchangers DEAE-cellulose and Q-Sepharose, followed by size exclusion chromatography on Superdex 75, which produced a purified enzyme with a high specific activity (170.0 U/mg) which was 130-fold higher than that of crude extract. The purified FAE exhibited activity toward synthetic methyl esters and short-chain fatty acid nitrophenyl esters. The Km and Vmax for this enzyme on methyl ferulate were 0.36 mM and 18.97 U/mg proteins, respectively. FAE activity was attained at a maximum at pH 4 and 40 °C, respectively. The FAE activity was inhibited by metal ions to various degrees. The purified FAE could bring about the release of ferulic acid from wheat bran and corn bran under the action of the single purified FAE, and the amount released from wheat bran rose to 51.9% (of the total amount) by the synergistic action of xylanase.

A feruloyl esterase (FAE) characterized by relatively high thermostability from the edible mushroom Russula virescens

A monomeric feruloyl esterase (FAE) with a molecular mass of 62 kDa was acquired from fresh fruiting bodies of the edible mushroom Russula virescens. The isolation procedure involved ion exchange chromatography on CM-cellulose, Q-Sepharose, and SP-Sepharose and finally fast protein liquid chromatography-gel filtration on Superdex 75. Two amino acid sequences were obtained after tryptic digestion, and they both showed some homology with the esterase of some fungi. Maximal activity was observed at pH 5.0 and at 50 °C. The enzyme displayed relatively high thermostability as evidenced by over 70 % residual activity at 70 °C and about 34 % residual activity at 80 °C. The K m and V max for this enzyme on methyl ferulate were 0.19 mM and 1.65 U/mg proteins, respectively. The purified FAE prefers methyl ferulate over methyl caffeate and is least active on methyl p-coumarate. The FAE activity was not significantly affected by the presence of cations such as Mn(2+), Ca(2+), Cd(2+), Zn(2+), Mg(2+), Cu(2+), and K(+) ions but inhibited by Al(3+), Hg(2+), Fe(2+), and Pb(2+) ions at a tested concentration of 2. 5 mM.

Purification and characterization of a highly thermostable esterase from the actinobacterium Geodermatophilus obscurus strain G20

Intracellular thermostable esterase produced by the extremophilic Geodermatophilus obscurus G20 was purified to homogeneity by a heat treatment, followed by an anion-exchange chromatography, and then characterized. The molecular weight of the purified enzyme determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was shown to be approximatively 55 kDa. The enzyme showed an optimal activity between pH 8.0 and 9.0 and was stable in the pH range 7.0-10.0. Moreover, it is highly thermostable, with a residual activity greater than 90% after incubation at 80 °C for more than 10 h. The enzyme showed preference for esters of p -nitrophenol with short chain fatty acid. When the p -nitrophenyl acetate (C2) was used as substrate, the Michaelis-Menten constant (K(m) ) and maximum velocity for the reaction (V(max) ) of esterase were 400 μM and 2500 U/mg protein, respectively. The effect of phenylmethanesulphonyl fluoride (PMSF), a serine-specific inhibitor, on the enzyme activity suggested that the thermostable esterase belong to the serine hydrolase group. Because of its high thermostability, activity at alkaline pH, tolerance to methanol and various metal ions and specificity for short chain fatty acids, this enzyme showed high potential for use in biocatalysis. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).