Effect of culture medium composition on the activity of extracellular lectins of Lentinus edodes

The time course of lectin production in culture liquid of the basidial fungus Lentinus edodes strain F-249 in different media under the conditions of submerged culture was studied. The activity of agglutinins depended on the ratio between carbon and nitrogen sources and pH of culture medium. The activity of lectin in culture medium was maximal when the fungus was grown in a medium containing L-arabinose as a source of carbon and L-asparagine as a source of nitrogen (C : N ratio, (9.5-12): 1)) on the day 15-18 of culturing at pH 8-9.     

Tolerance of tannin by the shiitake mushroom,Lentinus edodes

Summary Tannin at 1% (w/v) did not inhibit the growth ofLentinus edodes, but did inhibitPleuroius florida, P. sajor-caju, P. cystidosus, Agaricus bisporus andVolvariella volvacea. The inhibition was not due to its acidity.

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Tolérance de Lentinus edodes aux ajouts de tannin

Résumé Le tannin à la concentration de 1% (p/v) n'inhibe pas la croissance deLentinus edodes, mais inhibe celle dePleurotus florida, P. sajor-caju, P. cystidosus, Agaricus bisporus, etVolvariella volvacea. L'inhibition n'est pas due à son acidité.

     

Effect of freezing and thawing on cell membranes of Lentinus edodes,the shiitake mushroom

When cell membranes of Lentinus edodes mycelium were rapidly frozen at either 50 or 160°C/min, viability was lost and this correlated with rupture of the plasmalemma and residual membrane material and with alterations in the organelles. Although with slow cooling (1°C/min) 80% of the samples recovered viability, some cells still showed similar changes to those cooled rapidly, indicating that individual cells of the mycelium do not respond in the same way.     

Oral administration of levan polysaccharide reduces the alloxan-induced oxidative stress in rats

This study aimed to evaluate the effect of a polysaccharide named levan, which was produced by new isolated bacteria, on oxidative stress and hyperglycemia in alloxan-induced diabetic rats. Levan polysaccharide was given in drinking water for 60 days at a daily dose equivalent to 2%. The oral administration of levan in diabetic rats caused a decrease in glucose level in plasma and an increase of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities in both pancreas and liver. Furthermore, a protective action against hepatic and pancreatic toxicity in diabetic rats was clearly observed. Furthermore, a significant decrease in hepatic and pancreatic indices toxicity was observed, i.e., alkalines phosphatases (ALP), aspartate and lactate transaminases (AST and ALT), lactate deshydrogenases (LDH) activities and the thiobarbituric acid-reactive substances (TBARs). These beneficial effects of levan were confirmed by histological findings in hepatic and pancreatic tissues of diabetic rats. This study demonstrates for the first time that levan is efficient in inhibiting hyperglycemia and oxidative stress induced by diabetes and suggests that administration of levan may be helpful in the prevention of diabetic complications associated with oxidative stress.     

Composition and biological activity of submerged mycelium of the xylotrophic basidiomycete Lentinus edodes

The composition of submerged mycelium of Lentinus edodes, grown in laboratory fermenters, has been studied. The mycelium contained 23-24% proteins, 8-9% lipids, up to 1800 mg% phenolic substances, and a significant amount of inorganic substances, including calcium and iron. The fungus produced up to 5.0% intracellular and 3.5-4.0 g/l extracellular polysaccharides. The submerged mycelium stimulated the development of humoral immune response elicited by sheep red blood cells.     

Adaptation to oxidative stress and impact of chronic oxidative stress on immunity in heat-stressed broilers

1. Glutathione peroxidase activity and serum malondialdehyde of heat-stressed broilers were increased in the early period of heat exposure, and then these parameters decreased.

2. The lesion scores of bursa of Fabricius in heat-stressed broilers were increased and decreased in accordance with the activity of glutathione peroxidase and serum malondialdehyde.

3. High environmental temperature had not affected relative bursa of Fabricius weight and NDV-HI titer of heat-stressed broilers.

4. We concluded that heat-stressed broilers could adapt to oxidative stress, and environmental temperature set at 38±2 °C had not affected humoral immunity.

6-BA对平菇和香菇菌丝体两种同工酶的影响

通过在平菇、香菇的马铃薯液体培养基中添加不同浓度的 6 BA(6 苄基腺嘌呤 ) ,应用聚丙烯酰胺凝胶垂直平板电泳技术 ,探讨了 6 BA对平菇、香菇菌丝体酯酶 (EST)和过氧化物酶 (PER) 2种同工酶的影响。结果显示 ,6 BA浓度在 5 g/L培养液和 15 g/L培养液时分别诱导出平菇、香菇菌丝体中各 1条新的酯酶同工酶带产生 ,不同的 6 BA浓度对平菇、香菇菌丝体其余的酯酶同工酶带强度也有影响 ;6 BA不能诱导平菇和香菇菌丝体中新的过氧化物酶同工酶产生 ,但在浓度为 15 g/L培养液时可使PER同工酶带增强 ;6 BA对平菇和香菇菌丝体中EST ,PER2种同工酶的Rf值没有影响。     

Effect of nutrient nitrogen and manganese on manganese peroxidase and laccase production by Lentinula (Lentinus) edodes

Abstract Lentinula (Lentinus) edodes , strain LS4, produces manganese-dependent peroxidase (MnP) and laccase, but not lignin peroxidase, when grown on a defined medium with glucose as sole carbon source. MnP production is suppressed by nitrogen whereas highest levels of laccase were observed when the fungus was grown under high nitrogen (26 mM) conditions. Both the titre and time of appearance of MnP were affected by the concentration of Mn in the culture medium with highest enzyme levels recorded in cultures supplemented with 1.1 ppm Mn. Purified MnP from L. edodes LS4 has an apparent M _r of 59000 and a p I of 5.6, and differs in several respects from a MnP isolated from L. edodes grown on a commercial wood substrate.     

Purification and Some Properties of Nucleases from Shii-take,Lentinus edodes

Three kinds of nuclease preparations, each of which having both endonuclease activity that formed 5′-mononucleotides and 3′-nucleotidase activity, were separated and partially purified from Shii-take, Lentinus edodes. Both enzyme activities of each preparation showed a similar thermostability and electrophoretic mobility on Polyacrylamide gel, and a competitive relationship was observed between RNA and 3′-AMP in their enzyme reactions. From these results, it is concluded that both enzyme activities of these three preparations reside in a single protein, respectively. They resemble one another in substrate specificity, cleavage pattern of RNA and thermostability, but are distinguishable from one another by molecular weight, electrophoretic mobility and optimum pH for degradation of RNA.     

Molecular species of cerebrosides in fruiting bodies of Lentinus edodes and their biological activity

Cerebroside fraction was obtained from fresh fruiting bodies of Lentinus edodes and separated into ten molecular species by reverse-phase high-performance liquid chromatography. The species were identified by GLC, GC-MS and NMR. Their component glycosides and sphingoids were uniformly glucose and (4E,8E)-9-methyl-4,8-sphingadienine, respectively. The component fatty acids were 2-hydroxy acids with the carbon chain length of 16, 15, 14, 18, 24, 17, 25, 26, 22 and 23 (from major to minor). The cerebrosides with the C14-18 fatty acids showed strong fruiting-inducing activity in Schizophyllum commune. Those with the C22 and C23 ones had one-eighth and one-sixteenth of the activity, respectively, and those with C24-26 had no detectable activity. 22 and 23 must be the carbon chain lengths of the component fatty acid of the sphingolipids critical for expression of biological activity.     

The activity of the HIV-1 IRES is stimulated by oxidative stress and controlled by a negative regulatory element

Initiation of translation of the full-length messenger RNA of HIV-1, which generates the viral structural proteins and enzymes, is cap-dependent but can also use an internal ribosome entry site (IRES) located in the 5' untranslated region. Our aim was to define, through a mutational analysis, regions of HIV-1 IRES that are important for its activity. A dual-luciferase reporter construct where the Renilla luciferase (Rluc) translation is cap-dependent while the firefly luciferase (Fluc) translation depends on HIV-1 IRES was used. The Fluc/Rluc ratio was measured in lysates of Jurkat T cells transfected with the dual-luciferase plasmid bearing either the wild-type or a mutated IRES. Deletions or mutations in three regions decreased the IRES activity but deletion or mutations of a stem-loop preceding the primer binding site increased the IRES activity. The wild-type IRES activity, but not that of an IRES with a mutated stem-loop, was increased when cells were treated with agents that induce oxidative stress. Such stress is known to be caused by HIV-1 infection and we propose that this stem-loop is involved in a switch that stimulates the IRES activity in cells infected with HIV-1, supporting the suggestion that the IRES activity is up-regulated in the course of HIV-1 replication cycle.     

超滤分离和鉴定三种香菇多糖

用热水从香菇子实体中浸提出香菇多糖,采用两种超滤陶瓷膜将粗多糖分级成三部分Le1,Le2和Le3。所有的这三种多糖都由两组分所组成,采用凝胶过滤色谱测定了多糖分子量,13CNMR和IR光谱测定显示多糖Le1为含α糖甙键的多糖,多糖Le3为含β糖甙键的多糖。采用气相色谱法测定了三种多糖的单糖组成,结果显示三种多糖都由葡糖糖,阿拉伯糖,木糖,甘露糖和半乳糖组成,Le1,Le2和Le3中阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖的摩尔比分别为0.15∶0.52∶1.00∶1.20∶7.20、0.21∶0.68∶1.00∶1.02∶11.56、0.29∶0.42∶1.00∶0.85∶16.20。三种多糖Le1,Le2和Le3的平均分子量分别为4.02×104、2.16×105和8.93×105。     

Production and isolation of chitosan by submerged and solid-state fermentation from Lentinus edodes

A method for the laboratory-scale production and isolation of chitosan (polyglucosamine) by liquid and solidstate fermentation from Lentinus edodes was developed. The yields of isolated chitosan were 120 mg/L of fermentation medium under liquid fermentation conditions and 6.18 g/kg of fermentation medium under solid-state fermentation conditions. The latter method, which gives up to 50 times yields than other chitosan production methods from fungi, provides a new flexible and easily scaledup procedure for the production of low acetylation degree chitosan. (c) 1996 John Wiley & Sons, Inc.     

Effect of Triphala on oxidative stress and on cell-mediated immune response against noise stress in rats

Stress is one of the basic factors in the etiology of number of diseases. The present study was aimed to investigate the effect of Triphala (Terminalia chebula, Terminalia belerica and Emblica officinalis) on noise-stress induced alterations in the antioxidant status and on the cell-mediated immune response in Wistar strain male albino rats. Noise-stress employed in this study was 100 dB for 4 h/d/15 days and Triphala was used at a dose of 1 g/kg/b.w/48 days. Eight different groups of rats namely, non-immunized: control, Triphala, noise-stress, Triphala with noise-stress, and corresponding immunized groups were used. Sheep red blood cells (5×10⁹ cells/ml) were used to immunize the animals. Biochemical indicators of oxidative stress namely lipid peroxidation, antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), ascorbic acid in plasma and tissues (thymus and spleen) and SOD, GPx and corticosterone level in plasma were estimated. Cell-mediated immune response namely foot pad thickness (FPT) and leukocyte migration inhibition (LMI) test were performed only in immunized groups. Results showed that noise-stress significantly increased the lipid peroxidation and corticosterone level with concomitant depletion of antioxidants in plasma and tissues of both non-immunized and immunized rats. Noise-stress significantly suppressed the cell-mediated immune response by decreased FPT with an enhanced LMI test. The supplementation with Triphala prevents the noise-stress induced changes in the antioxidant as well as cell-mediated immune response in rats. This study concludes that Triphala restores the noise-stress induced changes may be due to its antioxidant properties.     

Effect of the Composition of Culture Media on the Laccase Production of Lentinus edodes Strains

The effect of charge, ion radii and concentration of cations and fermentation time on the laccase production of four Lentinus edodes strains was determined using 28 different fermentation media and 60 days of fermentation time. Samples were taken every 10 days and the laccase activity was determined by visible spectrophotometry. Principal component analysis (PCA) was used for the assessment of similarities and dissimilarities between the laccase activities of the samples. As PCA is not suitable for the separation of the strength (potency) and selectivity of the effect of various factors (composition of cultures, fermentation ime, Lentinus edodes strains) on the laccase production, they were separated by the spectral mapping technique (SPM). The dimensionality of the matrices of PC loadings and variables and the selectivity maps were reduced to two by the non‐linear mapping technique. The results of PCA and SPM were compared by calculating linear relationships among the potency values and the corresponding coordinates of PCA and SPM maps. It was established that neither the type of the cations nor their concentration in the fermentation media had a significant effect on the laccase production. It was found that the type of the Lentinus edodes strains and the fermentation time exerts a considerable effect both on the strength and on the selectivity of the laccase production. It was further proven that the results of PCA and SPM were considerably different. Therefore, their simultaneous application in future quantitative structure activity relationship (QSAR) studies is highly recommended.     

Effect of lignin-derived phenolic monomers on the growth of the edible mushrooms Lentinus edodes,Pleurotus sajor-caju and Volvariella volvacea

Pleurotus sajor-caju was generally more tolerant to lignin-related phenolic monomers and tannin derivatives than Lentinus edodes and the straw mushroom, Volvariella volvacea. Several phenols, at up to 5 mM, enhanced mycelial growth of P. sajor-caju. No clear pattern was evident when the effects of phenols and tannins on the growth of V. volvacea and L. edodes were compared, but the lower concentrations of 4-hydroxybenzaldehyde and vanillin which were tested were markedly more toxic to the straw mushroom. The distribution of phenolic monomers and tannin derivatives in the agricultural wastes used for mushroom cultivation may be an important growth determinant. However, the differences in the growth inhibition profiles of L. edodes, P. sajor-caju and V. volvacea suggest that, alone, the effect of these compounds on fungal growth is unlikely to account for the varying abilities of the three mushroom species to grow and fruit on a particular lignocellulosic substrate.     

Synergized subcritical-ultrasound-assisted aqueous two-phase extraction,purification, and characterization of Lentinus edodes polysaccharides

The effect of a synergized two-step subcritical water extraction (SWE) and simultaneous multi-frequency ultrasound-assisted alcohol/salt aqueous two-phase extraction (MFu-AATPE) on the yield, physicochemical, structural characteristics, and antioxidant activities of Lentinus edodes polysaccharides (LEPs) was investigated. Crude LEP extracted under subcritical extraction (31.14%) was purified using dual and triple frequency ultrasound-assisted aqueous two-phase systems giving a yield of 94.57% and 97% respectively. Compared with the dual-frequency sonication (20/40 kHz), the triple frequency sonication (20/40/60 kHz) gave maximum yield and improved the desalination rate by 33.6%. Congo red analysis revealed triple helix structures. Gas Chromatography analysis showed the existence of mannose, glucose, arabinose, xylose, and galactose whilst spectral similarities were observed through Fourier Transform Infrared Spectroscopy. The average molecular weight (M_w) was 83.6170 Da, 2384 Da and 2387 Da for control, dual and triple frequency samples respectively. Ultrasound treated polysaccharides displayed stronger antioxidant activities against the 2.2-diphenyl;-1 picrylhydrazyl (DPPH), 2, 2ʹ-azino-bis 3-ethylbenzothiazoline-6 sulfonic acid (ABTS) and hydroxyl radicals, thus demonstrating their potency in reducing oxidation. However, the microstructure of the triple frequency treated sample was altered compared to the dual-frequency sample. Therefore, this study demonstrated the efficacy of SWE in crude LEPs extraction and illustrated MFu-AATPE as an efficient technique that selectively isolates polysaccharides and enhances extraction efficiencies.     

Effect of aerobic exercise intervention on DDT degradation and oxidative stress in rats

Dichlorodiphenyltrichloroethane (DDT) reportedly causes extensively acute or chronic effects to human health. Exercise can generate positive stress. We evaluated the effect of aerobic exercise on DDT degradation and oxidative stress.Main methods: Male Wistar rats were randomly assigned into control (C), DDT without exercise training (D), and DDT plus exercise training (DE) groups. The rats were treated as follows: DDT exposure to D and DE groups at the first 2 weeks; aerobic exercise treatment only to the DE group from the 1st day until the rats are killed. DDT levels in excrements, muscle, liver, serum, and hearts were analyzed. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) levels were determined. Aerobic exercise accelerated the degradation of DDT primarily to DDE due to better oxygen availability and aerobic condition and promoted the degradation of DDT. Cumulative oxidative damage of DDT and exercise led to significant decrease of SOD level. Exercise resulted in consistent increase in SOD activity. Aerobic exercise enhanced activities of CAT and GSH-Px and promoted MDA scavenging. Results suggested that exercise can accelerate adaptive responses to oxidative stress and activate antioxidant enzymes activities. Exercise can also facilitate the reduction of DDT-induced oxidative damage and promoted DDT degradation. This study strongly implicated the positive effect of exercise training on DDT-induced liver oxidative stress.     

Effect of methanol-induced oxidative stress on the neuroimmune system of experimental rats

It is well known that the nervous system has increased susceptibility to methanol intoxication. The present study reveals the effect of methanol intoxication on antioxidant status, lipid peroxidation and DNA integrity in hypothalamic-pituitary-adrenal (HPA) axis organs and spleen. Non-specific and specific immune functions were analyzed. In addition, open field behavior, plasma corticosterone level and blood methanol level were estimated. Male Wistar albino rats were intoxicated with methanol (2.37 g/kg b.wt., i.p.) for 1 day, 15 and 30 days. Administration of methanol showed significant increase in enzymatic (superoxide dismutase, catalase, glutathione peroxidase), non-enzymatic (reduced glutathione and Vitamin C) antioxidants and lipid peroxidation (LPO) in hypothalamus and adrenal gland of day 1 group. However, decrease in enzymatic and non-enzymatic antioxidants with concomitant increase in LPO level were observed in 15 and 30 days groups. Plasma corticosterone level was significantly increased in day 1 and 15 days groups whereas, 30 days methanol intoxication group showed considerable decrease in corticosterone level compared with control animals. Cell-mediated immune response of footpad thickness was significantly decreased with an increased leukocyte migration inhibition. Humoral immune response of antibody titers was elevated in methanol-intoxicated groups. Neutrophil functions, adherence and phagocytic index (PI) were found to be significantly decreases. Furthermore, significant increase in the avidity index and nitro blue tetrozolium reduction was observed in the methanol exposed animals. Day 1 methanol exposed group showed increased PI compared to the control ones. Methanol exposure for 30 days showed an increased DNA fragmentation in the hypothalamus, adrenal glands, and spleen. In conclusion, exposure to methanol-induced oxidative stress disturbs the HPA-axis function altering the level of corticosterone, which lead to varied non-specific and specific immune response in experimental rats.