Lipid profile of Pleurotus sajor caju

The lipid profile of Pleurotus sajor caju was studied in relation to mycelial and sporophore growth and different cultural factors. The growth was characterised by lipid synthesis during mycelial growth and utilisation during sporophore growth. The degree of instauration increased during mycelial growth and decreased during sporophore formation. The fatty acid composition of mycelium and sporophore was similar, linoleic acid (C_18:2) being the most dominant acid in both. C:N ratio had a significant (P<0.05) positive effect on mycelial dry weight; however, per cent total lipids was similar. Non-polar lipids became more unsaturated as the temperature was raised from 10° to 25°C and pH from 3.0 to 6.0, but declined when the cultures were aerated. Mycelial dry weight increased significantly (P<0.05) when the liquid medium was supplemented with lipids. In general, fatty acids with carbon chain length C₁₆ and C₁₈ stimulated the growth of mycelium. Supplementation of solid substrate (cotton seed hulls) with safflower oil, soybean oil or rice bran significantly (P<0.05) increased the yield of sporophores. Total lipids and ratio of non-polar to polar lipids were not affected by lipid supplementation.     

Lipid metabolism of Pleurotus sajor caju

The biosynthesis of lipids in the mycelium and sporophore of Pleurotus sajor caju was studied. Whereas in the mycelium the biosynthesis of lipids was directly primarily towards storage (e.g. tri-acylglycerols), in the sporophore it was directed towards structural components (e.g. sterols). The incorporation of ¹⁴C precursors into non-polar and polar lipid fractions was generally similar for ¹⁴C acetate, ¹⁴C palmitate, ¹⁴C oleate and ¹⁴C linoleate in the case of mycelium and sporophore. It appears that linoleic acid was utilised as a source of acetate for lipid biosynthesis in the sporophore. A significantly higher incorporation of label was seen in sporophore sterol than in mycelial sterol. Malate dehydrogenase activity increased in the mycelium grown in the presence of lipids. Lipase of P. sajor caju was inducive. The growth of P. sajor caju was enhanced by increased lipid utilisation. The implications of these results on commercial cultivation of this fungus are discussed.     

Removal of chlorophenols from aquatic systems using the dried and dead fungus Pleurotus sajor caju

In this study, the potential use of the fungus Pleurotus sajor caju to remove phenols (i.e., phenol, o-chlorophenol, p-chlorophenol and 2,4,6-trichlorophenol) from aqueous solutions was evaluated. Biosorption of phenol or chlorophenols reached equilibrium in 4 h. The maximum adsorptions of phenol and chlorophenols onto the Pleurotus sajor caju were 0.95 mmol/g for phenol, 1.24 mmol/g for o-chlorophenol, 1.47 mmol/g for p-chlorophenol and 1.89 mmol/g for 2,4,6-trichlorophenol. The affinity order was as follows: 2,4,6-trichlorophenol> p-chlorophenol> o-chlorophenol>phenol. Phenol and chlorophenols bindings onto Pleurotus sajor caju were clearly pH dependent. The adsorption of phenol and chlorophenols increased with increasing pH. Desorption was achieved using methanol solution (30%, v/v). Pleurotus sajor caju biomass is suitable for reuse for more than five cycles without noticeable loss of adsorption capacity.     

Production and characterization of an exopolysaccharide from Rhizobium hedysari HCNT 1

Rhizobium hedysari strain HTCN 1 produces viscous fermentation broths due to the presence of exopolysaccharide (EPS) products. Production of these products has been studied by testing a wide range of C- and N-sources. The highest EPS yield (9.04 g/L) has been obtained after 7 days cultivation in shaken flask on mannitol and lysine. The isolated and purified EPS has been subjected to chemical identification by means of NMR and FTIR spectroscopies.     

Production and characterization of laccase from Pleurotus ferulae in submerged fermentation

Pleurotus ferulae is a mushroom typically found in arid steppe that is distributed widely in the Junggar Basin of Xinjiang, China. In this work, laccase production by P. ferulae JM30X was optimized in terms of medium composition and culture conditions. After optimization, the highest laccase activity obtained was 6,832.86 U/L. A single isozyme with a molecular weight of 66 kDa was observed by SDS-PAGE and native-PAGE. Optimum pH and temperature were 3.0 and 50–70 °C, respectively. The best laccase substrate was ABTS, for which the Michaelis-Menten constant (K _m) and catalytic efficiency (K _cat/K _m) value for P. ferulae laccase were 0.193 mM and 2.73?×?10⁶ (mM s)^?1, respectively. The activity of purified laccase was increased by more than four-fold by Cu²⁺, Mn²⁺ and Mg²⁺, while it was completely inhibited by Fe²⁺ and Fe³⁺. The production of laccase was influenced by the initial pH and K⁺ concentration, and the activity of purified laccase was enhanced by Cu²⁺, Mn²⁺ and Mg²⁺. This Pleurotus genus laccase from P. ferulae JM30X was analyzed by MS spectrum and the results are conducive to furthering our understanding of Pleurotus genus laccases.     

Production of exopolysaccharide from ethanol inAgrobacterium radiobacter

Agrobacterium radiobacter produces an extracellular polysaccharide from various carbon sources. The exopolysaccharide is produced from ethanol also in a minimal medium containing nitrate as the sole nitrogen source. On cultivation in a medium without CaCO₃ only a minute amount of ethanol is converted to the exopolysaccharide. Both ethanol and nitrate in higher concentrations inhibit the growth rate. In a medium with CaCO₃ the proportion of ethanol converted to the polysaccharide is about ten-fold higher and the inhibitory effect of ethanol and nitrate on the growth rate is analogous to that found in the medium without CaCO₃-Comparison of results of mass and electron balance with a kinetic model shows that the parameters obtained in cultivations with CaCO₃ are less reliable. The balances point to the possibility of formation of other extracellular products.     

Production,isolation and preliminary characterization of the exopolysaccharide of the cyanobacterium Spirulina platensis

Summary The soluble exocellular polysaccharide secreted by the filamentous cyanobacteria Spirulina platensis is a primary metabolite. It is formed by ten different types of monomer units including six neutral sugars (xylose, rhamnose, fucose, galactose, mannose and glucose in the proportions 1.3/0.3/0.7/2.7/traces/2), two unidentified sugars, two uronic acids and sulphate groups accounting for 40 % and 5 % respectively of the mass of the molecule. This polysaccharide displays a non Newtonian behaviour and a strong pseudoplastic characteristic that may originate in the polyelectrolytic property of the molecule.     

Production, purification and characterization of laccase from Pleurotus ostreatus grown on tomato pomace

A strain of Pleurotus ostreatus was grown in tomato pomace as sole carbon source for production of laccase. The culture of P. ostreatus revealed a peak of laccase activity (147 U/L of fermentation broth) on the 4th day of culture with a specific activity of 2.8 U/mg protein. Differential chromatographic behaviour of laccase was investigated on affinity chromatographic matrices containing either urea, acetamide, ethanolamine or IDA as affinity ligands. Laccase exhibited retention on such affinity matrices and it was purified on a Sepharose 6B—BDGE—urea column with final enzyme recoveries of about 60%, specific activity of 6.0 and 18.0 U/mg protein and purification factors in the range of 14–46. It was also possible to demonstrate that metal-free laccase did not adsorb to Sepharose 6B—BDGE—urea column which suggests that adsorption of native laccase on this affinity matrix was apparently due to the specific interaction of carbonyl groups available on the matrix with the active site Cu (II) ions of laccase. The kinetic parameters (V _max, K _m , K _cat, and K _cat/K _m ) of the purified enzyme for several substrates were determined as well as laccase stability and optimum pH and temperature of enzyme activity. This is the first report describing the production of laccase from P. ostreatus grown on tomato pomace and purification of this enzyme based on affinity matrix containing urea as affinity ligand.     

Production and characterization of monoclonal antibodies specific for Shewanella colwelliana exopolysaccharide.

Six monoclonal antibodies were produced to whole cells of Shewanella colwelliana (Aco1 to Aco6) and two (Aco22 to Aco23) to purified exopolysaccharide (EPS). Aco1, -4 to -6, -22, and -23 bound to both the cell surface and the purified EPS, while Aco2 and -3 bound to cells only. The EPS of S. colwelliana was antigenically unique from those of nine other species of marine bacteria that were tested. Mapping studies revealed that all of the EPS-specific monoclonal antibodies bound to the same epitope. This EPS epitope was sensitive to cleavage of ester bonds, but neither pyruvate, acetate, nor terminal nonreducing sugars were required for antigenicity. When S. colwelliana was grown on rich media, most of its EPS was loosely associated with the cell surface.     

Purification and partial characterization of a fibrinolytic enzyme from the fruiting body of the medicinal and edible mushroom Pleurotus ferulae

A fibrinolytic metalloprotease with in vitro fibrinolytic effects was purified from the edible mushroom Pleurotus ferulae using several chromatography steps including anion and ion exchange, gel filtration, and fast protein liquid chromatography columns. The molecular mass of the enzyme was estimated to be 20.0?kDa, as determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fibrin zymography. The protease was active at 50°C, and pH 4.0, 5.0, and 8.0. The fibrinolytic activity of the enzyme was inhibited by ethyleneglycol-bis-(2-aminoethyl)-N,N,N′,N′ tetraacetic acid and strongly inhibited by two metal ions, Cu and Mg. In vitro assays evaluating fibrinolytic activity on a fibrin plate, fibrin turbidity, and thrombolytic activity on fibrin clots using human fibrinogen and human thrombin revealed that the enzyme could hydrolyze fibrin polymers directly and inhibit the formation of fibrin clots. In activated partial thromboplastin time (APTT) and prothrombin time assays, the enzyme strongly prolonged the APTT, which detects an activity of intrinsic and common pathways. The enzyme showed strong in vivo protective effect against mortality/paralysis from epinephrine plus collagen-induced acute thromboembolism in in vivo model. Our findings suggest that the enzyme may have a potential for treatment and prevention of thrombosis-relative diseases.     

Biochemical characterization of the exopolysaccharide purified from Laetiporus sulphureus mycelia

The extracellular polysaccharide (EPS) was isolated from mycelial cultures of Laetiporus sulphureus var. miniatus and purified by DEAE cellulose and Sephadex G-50 column chromatography. The purified EPS (EPS-2-1) was composed of only glucose units and its molecular mass was 6.95 kDa. The chemical structure of EPS-2-1 consisted of a main chain containing (1-->4)-Glcp units with branches at the C-6 position of the chain carrying -Glcp-(1-->4)-linked residues. The effect of purified EPS on immunomodulatory genes and proteins of the Bcl-2 family was observed using cultured U937 human leukemia cells. Of note, the levels of Bax and Bad proteins treated with the EPS (4 mg/ml) were approximately 23- and 18-times higher than those in non-treated cells, respectively. These results may suggest that the EPS purified from the mushroom L. sulphureus is associated with the activation of immunomodulatory mediators, Bax and Bad proteins.     

Extraction and characterization of an exopolysaccharide from a marine bacterium

International Microbiology - The marine bacterial exopolysaccharides (EPS) have transfigured the biotech sector with their myriad applications and prospects. This work was carried out to...     

Production and partial characterization of dehairing protease from Bacillus cereus MCM B-326

Bacillus cereus MCM B-326, isolated from buffalo hide, produced an extracellular protease. Maximum protease production occurred (126.87+/-1.32 U ml(-1)) in starch soybean meal medium of pH 9.0, at 30 degrees C, under shake culture condition, with 2.8 x 10(8) cells ml(-1) as initial inoculum density, at 36 h. Ammonium sulphate precipitate of the enzyme was stable over a temperature range of 25-65 degrees C and pH 6-12, with maximum activity at 55 degrees C and pH 9.0. The enzyme required Ca(2+) ions for its production but not for activity and/or stability. The partially purified enzyme exhibited multiple proteases of molecular weight 45 kDa and 36 kDa. The enzyme could be effectively used to remove hair from buffalo hide indicating its potential in leather processing industry.     

Production of bacteriocin by Bacteriodes fragilis and partial characterization

The ability of Bacteroides fragilis strains, isolated from various sources, to produce bacteriocin was evaluated. All strains isolated from intestinal infections were producers in high levels and less susceptible to the others. Strains from other origins were found to produce bacteriocin at a medium level and they were variably susceptible. Some properties of one bacteriocin produced by the Bact. fragilis 079298-3 strain were analysed, providing evidence of its protein nature, with stability over a wide range of pH and retained inhibitory activity after heating. This variability seems to suggest that bacteriocin typing is a good method for this species.     

Kinetics of production and characterization of the fucose-containing exopolysaccharide from Enterobacter A47

A fucose-containing exopolysaccharide (EPS) was produced by the bacterium Enterobacter A47 using glycerol byproduct from the biodiesel industry. The analysis of kinetic data suggested a partially growth associated EPS synthesis model. Although the EPS was composed of fucose, galactose and glucose at all cultivation stages, their relative proportion has varied considerably during the run. At the beginning (24h), glucose was the main component (82.4 wt.%), being fucose and galactose minor components (5.0 wt.% and 10.9 wt.%, respectively), while at the end (96 h) it was composed of 26.0 wt.% fucose, 28.9 wt.% galactose and 43.7 wt.% glucose. The acyl groups content and composition have also changed, reaching their maximum content (19.2wt.%) at the end of the run. Moreover, the molecular weight has increased linearly during the run (from 8×10(5) to 5×10(6)). The changes observed in EPS composition and molecular weight have also had an impact upon the polymer's intrinsic viscosity, as shown by its linear increase from 3.95 to 10.72 dL g(-1). The results suggest that the culture might have synthesized at least two distinct EPS, with different sugar composition and average molecular weight, which predominated at different cultivation stages.     

Purification and chemical characterization of an exopolysaccharide isolated from Capnocytophaga ochracea

Purification and chemical characterization of an immunosuppressive exopolysaccharide from Capnocytophaga ochracea strain 25 are described. This polysaccharide was extracted from spent culture medium by cold ethanol precipitation. Purification was accomplished by trichloroacetic acid and pronase treatments in combination with diethylaminoethyl-Sepharose and concanavalin A-Sepharose chromatography. Purity of the exopolysaccharide was ascertained by polyacrylamide gel electrophoresis using periodic acid--Schiff staining. The exopolysaccharide was free of protein, nucleic acid, and lipopolysaccharide, but contained large amounts of mannose with lesser quantities of glucose, galactose, glucuronic acid, and glucosamine.     

刺芹侧耳芳基醇氧化酶的分离纯化及其酶学性质

分离纯化刺芹侧耳Pleurotus eryngii芳基醇氧化酶,并探究其酶学性质。通过硫酸铵盐沉、DEAE-Sepharose Fast Flow弱阴离子交换层析、Sephacryl S-200 High Resolution凝胶过滤层析和Source 15Q强阴离子交换层析,得到纯化的单一酶。经肽指纹图谱鉴定,确定其为芳基醇氧化酶,酶活回收率25.5%,纯化倍数38.2。结合SDS-PAGE和IEF-PAGE分析,确定其分子量和等电点分别为70kDa和4.2。以藜芦醇为底物,该酶最适反应pH为6.0,最适反应温度为70℃,金属离子Zn²⁺、Fe²⁺和Cu²⁺对芳基醇氧化酶的活性抑制作用明显,K_m和V_max分别为0.921mmol/L和80U/mg。     

Production and molecular characterization of somatic hybrids between Pleurotus florida and Lentinula edodes

Nine inter-generic somatic hybrids named as pfle were produced through PEG-mediated protoplast fusion between Pleurotus florida and Lentinula edodes using double selection method. Hybridity of the newly developed strains was established on the basis of colony morphology, mycelial growth, hyphal traits, fruit-body productivity and inter single sequence repeat (ISSR) marker profiling. Hybrid population was assessed with different phenotypic variables by one-way analysis of variance. Principal component matrices were analyzed for the six phenotypic variables in scatter plot showing maximum positive correlation between each variable for all strains examined. Six ISSR primers generated 66 reproducible fragments with 98.48 % polymorphism. The dendrogram thus created based on unweighted pair-group method with mathematic averages method of clustering and Euclidean distance which exhibited three major groups between the parents and pfle hybrids. Though P. florida parent remained in one group but it showed different degrees of genetic distance with all the hybrid lines belonging to the other two groups while L. edodes was most distantly related to all the hybrid lines. L. edodes specific sequence-rich ISSR amplicon was recorded in all the hybrid lines and in L. edodes but not in P. florida. All the fruit body generating pfle hybrid lines could produce basidiocarp on paddy straw in sub-tropical climate and showed phenotypic resemblance to the P. florida parent.     

Production and partial characterization of elastase of Bacillus subtilis isolated from the cervices of human females

Conditions are described for the production of extracellular elastase by Bacillus subtilis. The yield of enzyme was maximum in shake-cultures grown in Syncase medium at 37 degrees C and was stable in culture supernatants. The enzyme, purified by ammonium sulphate precipitation and Sephadex G-75 gel filtration, showed a molecular weight of 25,000 and activity between pH 6.0 and 9.5, with an optimum of 9.0 in Tris-maleate buffer. Elastinolytic activity was maximum in glycine-NaOH buffer and minimum in phosphate buffer. Enzyme activity was adversely affected by temperature greater than or equal to 40 degrees C.