Cultivation of the oyster mushroom (Pleurotus ostreatus) on lignocellulosic waste

The establishment of a small-scale production facility for Pleurotus ostreatus is described and environmental and yield data are presented. The average yield was c. 50% fresh weight mushroom/dry weight substrate when grown on 40% cocoa shell waste, 40% softwood sawdust, 19% oatmeal and 1% carboxymethyl cellulose. The mushroom fruited when daily temperatures ranged between 11 and 27°C.     

Hypocholesterolemic and antiatherogenic effect of oyster mushroom (Pleurotus ostreatus) in rabbits

The addition of 10% dried fruiting bodies of oyster mushroom (Pleurotus ostreatus) to the diet containing 1% of cholesterol reduced serum cholesterol levels by 65% and cholesterol content in liver, heart, long extensor muscle and aorta of male rabbits (Chinchilla) by 60, 47, 25 and 80%, respectively. The decrease in total serum cholesterol was affected primarily (by 70%) by reduced cholesterol content in very-low-density lipoproteins (VLDL) while the contribution of high density lipoproteins (HDL) cholesterol increased by a factor of 3. Oyster mushroom diet reduced by 60–70% the content of conjugated dienes in plasma, erythrocytes and liver, however, it did not affect significantly the activities of antioxidant enzymes. Oyster mushroom diet reduced significantly the incidence of atherosclerotic plaques as estimated by sudanophilia (absence of positive-reaction in 3 of 5 animals) as well as plaque size (26% vs. 2% of the area with positive reaction in control and oyster mushroom-treated animals, respectively). While all animals on control diet showed atherogenic changes in aorta, oyster mushroom diet prevented the development of these changes in three animals. Fatty streaks and fibromatous plaques were found in the remaining two animals from this group. Oyster mushroom prevented the formation of atheroma plaques (found in three cases from the control diet group) and reduced the incidence of segmental injury of coronary arteria and of focal fibrosis of myocardium. Oyster mushroom caused lower incidence of foam cells in all types of lesions.     

Hypocholesterolemic and antiatherogenic effect of oyster mushroom (Pleurotus ostreatus) in rabbits.

The addition of 10% dried fruiting bodies of oyster mushroom (Pleurotus ostreatus) to the diet containing 1% of cholesterol reduced serum cholesterol levels by 65% and cholesterol content in liver, heart, long extensor muscle and aorta of male rabbits (Chinchilla) by 60, 47, 25 and 80%, respectively. The decrease in total serum cholesterol was affected primarily (by 70%) by reduced cholesterol content in very-low-density lipoproteins (VLDL) while the contribution of high density lipoproteins (HDL) cholesterol increased by a factor of 3. Oyster mushroom diet reduced by 60-70% the content of conjugated dienes in plasma, erythrocytes and liver, however, it did not affect significantly the activities of antioxidant enzymes. Oyster mushroom diet reduced significantly the incidence of atherosclerotic plaques as estimated by sudanophilia (absence of positive-reaction in 3 of 5 animals) as well as plaque size (26% vs. 2% of the area with positive reaction in control and oyster mushroom-treated animals, respectively). While all animals on control diet showed atherogenic changes in aorta, oyster mushroom diet prevented the development of these changes in three animals. Fatty streaks and fibromatous plaques were found in the remaining two animals from this group. Oyster mushroom prevented the formation of atheroma plaques (found in three cases from the control diet group) and reduced the incidence of segmental injury of coronary arteria and of focal fibrosis of myocardium. Oyster mushroom caused lower incidence of foam cells in all types of lesions.     

Cultivation of Pleurotus ostreatus mushroom in peat

Pleurotus ostreatus (oyster mushroom) was cultivated in a peat moss based substrate. Acid-hydrolysed peat and non-hydrolysed peat were used in the preparation of the spawn and in the further stage of growing the mushroom fruiting bodies. For comparison, P. ostreatus was also cultivated on paper. Three harvests of mushrooms were obtained in 45 days. The highest total yield gave 10% conversion of peat substrate into mushroom biomass. The mushrooms had 36% crude protein content and all the essential amino acids were present.     

Effect of oyster mushroom (Pleurotus Ostreatus) and its ethanolic extract in diet on absorption and turnover of cholesterol in hypercholesterolemic rat

The effect of the diet containing 5% of powdered oyster mushroom (Pleurotus ostreatus) or an equivalent amount of mushroom ethanolic extract on cholesterol content in serum and liver, on its distribution in lipoproteins, absorption and turnover was studied in male Wistar rats (initial body weight about 70 g) fed a diet with 0.3% cholesterol. 12 weeks of feeding with whole oyster mushroom or mushroom extract reduced cholesterol level in serum by 52 and 33%, respectively. However, cholesterol content in liver was reduced only by whole oyster mushroom (by 20%). Diminished serum cholesterol level was mediated in 60% by reduction of cholesterol in very-low-density lipoproteins. Both whole oyster mushroom and mushroom extract increased the concentration of cholesterol in high-density lipoproteins. Consuming whole oyster mushroom decreased cholesterol absorption (estimated by dual-isotope plasma ratio method) by nearly 16% while no significant effect of mushroom extract could be demonstrated. Feeding the diet containing whole oyster mushroom or its extract reduced the half-times of decay curve of cholesterol-4-¹⁴C by 29 and 35%, respectively and reciprocally increased the fractional catabolic rate of plasma cholesterol.     

Extracts of oyster mushroom (Pleurotus ostreatus) grown on wheat ameliorate hepatotoxicity induced by carbon tetrachloride in rats

Pleurotus ostreatus (PO), which is also called the oyster mushroom, is the secondly most popular cultivated mushroom in the world and has been shown to display antioxidant activity. In this study, the hepatic protective effects of extracts of PO cultured in wheat (POW) on carbon tetrachloride (CCl₄)-induced liver injury in rats were evaluated by analyzing blood markers of liver injury. Sprague-Dawley rats were pretreated with POW extracts (0, 0.5, and 1.0 g/kg) orally for 14 days prior to the administration of CCl₄ for 3 days. Marked evaluation of alanine and aspartate aminotransferases, lactate dehydrogenase, alkaline phosphatase, and γ-glutamyltransferase were observed in the plasma from control rats after CCl₄ treatment. This increased liver injury markers were significantly reduced in a dose-dependent manner by pretreatment with the POW extract, suggesting that POW prevented acute liver damage in CCl₄-intoxicated rats by suppressing cellular leakage and loss of the functional integrity of cell membranes in the liver. POW extracts could also improve lipid profiles damaged caused by CCl₄ in liver through a reducing plasma triglyceride and total cholesterol and a recovering plasma HDL-cholesterol. These results suggest that the extracts of POW ameliorate hepatotoxicity induced by CCl₄ in the rat model.     

Effects of different agro-industrial waste as substrates on proximate composition,metals, and mineral contents of oyster mushroom (Pleurotus ostreatus)

The use of agro-industrial waste as substrates for mushroom cultivation is considered a promising management strategy for reducing and valorising these wastes, simultaneously reducing the cost of mushroom cultivation. In this study, oyster mushroom Pleurotus ostreatus were cultivated on twelve substrates composed of either tea waste, lime sawdust, alder sawdust, hornbeam sawdust/shaving, wheat stalk-straw, wheat bran or their composite to determine the proximate composition and accumulation of thirteen elements in their fruiting bodies. The proximate composition of P. ostreatus did not show a significant difference, regardless of the employed substrate. (one-way manova ; F_{(66, 107)} = 1.329, Wilk’s λ = 0.041, P > 0.05). However, their chemical element contents show a statistically significant difference (one-way manova ; F_{(132, 418)} = 32.163, Wilk’s λ = 0.000, P < 0.05). These results were supported by discriminant function and principal component analyses. The highest mean concentrations of six of twelve elements (i.e., Ca, Mg, Na, Zn, Cd and Cr) were recorded in P. ostreatus cultivated on the lime-sawdust substrate. Three health indices viz., estimated daily intake, target hazard quotient (THQ) and total THQ were applied to determine the risk to human health via the consumption of P. ostreatus, suggesting that they are safe for human consumption.     

Post-harvest physiology and storage of the white oyster mushroom Pleurotus flabellatus

Changes in the post-harvest storage of the mushroom Pleurotus jlabellatus at ambient temperature were studied. There was a decrease in respiratory rate and soluble carbohydrates along with loss in water content. With progress in period of storage, the fresh mushrooms showed an increase in the activities of 0-diphenoloxidases and proteases accompanied with decrease of total phenols and increase in free amino acids respectively. The degree of discoloration increased with the lapse of storage time.
Fresh mushrooms (200 g) packed in 25 μm thick polyethylene bags (16 × 25 cm) with one pin hole on either side stored up to a period of 24 hr at ambient temperature and up to a period of 6 days at 5 ± 2°C in the intact polyethylene bags.     

Influence of water and ethanol extracts of the oyster mushroom (Pleurotus ostreatus) on serum and liver lipids of the Syrian hamsters

Extracts from the dried and ground fungus were prepared with water and with 30%, 60% and 85% ethanol, and thickened in vacuum. The whole fungus and extracts were added to the hyperlipemizing diet in amounts equivalent to 3% of the whole fungus. After 6 weeks the whole fungus, its water as well as 30% and 60% ethanol extracts have significantly reduced the contents of cholesterol (C) and triacylglycerols (TG) in the serum. The C and TG contents of the liver were reduced by 34–48% (in the case of TG insignificantly when applying the water and 60% ethanol extracts). The 85% ethanol extracts reduced the C and TG levels in both serum and liver statistically insignificantly by 18–22%. The reduction of serum C by addition of the whole fungus and its water and 30% ethanol extract was decisively affected by the reduction in the C contents in the very low density fraction of lipoproteins.     

Compression properties of the fruit body of king oyster mushroom Pleurotus eryngii

To investigate the textural properties of edible fungi, raw and boiled cubic samples cut from stipe of the king oyster mushroom Pleurotus eryngii were compressed from various directions by different type utensils, and their deformed tissue structures were examined. Differences in the loads between compress directions were observed by the homogenous compression. A significant difference between the loads of the boiled upper (~10 N) and lower (~12 N) portions of stipe by intrusive compression from parallel to the growth direction was found. In the scanning electron microscopy (SEM) images, the arrangement of fibrous spawn in the lower‐portion tissue was characterised by curl‐like formations. The fibre also appeared tangled in irregular arrangements. The results of this study indicate that the firmness of mushroom tissue was produced by the complex attributes, which were the mechanical strength and physicochemical bindings of the fibre, and that the fibre arrangement and/or formation of the tissue.     

The fate of Cry1Ac Bt toxin during oyster mushroom (Pleurotus ostreatus) cultivation on transgenic Bt cottonseed hulls

BACKGROUND: In China, mushrooms are often cultivated on cottonseed hulls, and spent substrates from their cultivation are used as cattle feed. As the area planted to Bacillus thuringiensis (Bt) cotton in China increases, hulls from transgenic Bt cottonseed are being increasingly used as a substrate for edible mushroom cultivation. The objective of this research was to determine whether Bt toxin was transmitted to mushrooms cultivated on transgenic Bt cottonseed hulls or retained in the spent substrate. RESULTS: Bt toxin was still present in transgenic Bt cottonseed hulls after chemical (carbendazol) treatment but not after heat (100 °C) treatment before mushroom fungus inoculation. When mushroom was cultivated on carbendazol‐treated substrates, Bt toxin level in the substrates fell below the detection limit (1.5 ng Cry1Ac per g fresh weight) in 15 days. CONCLUSION: Bt toxin was not transmitted to mushrooms during cultivation on transgenic Bt cottonseed hulls. Copyright © 2007 Society of Chemical Industry     

In vitro antioxidative and antimutagenic activities of oak mushroom (Lentinus edodes) and king oyster mushroom (Pleurotus eryngii) byproducts

The in vitro antioxidative and antimutagenic activities of ethanolic extracts from oak mushroom (Lentinus edodes) and king oyster mushroom (Pleurotus eryngii) byproducts were investigated. The antioxidant capacity of the extracts was assessed by determining the ferricyanide reducing power, scavenging activity on nitrite, DPPH radical, superoxide anions and hydroxyl radicals, ferrous ion chelating ability, and inhibitory effect on linoleic acid peroxidation and xanthine oxidase. The antimutagenic activity, on the other hand, was based on the suppression of mitomycin C-induced mutagenesis in Escherichia coli cells. Both the mushroom extracts showed strong antioxidative and antimutagenic effects at higher concentrations. In general, extracts from the oak mushroom byproduct had greater antioxidative and antimutagenic abilities than that of the king oyster extract. Results of this study demonstrate that the mushroom byproducts possess strong antioxidant capacity in vitro and may be useful as a functional biomaterial in the preparation of health-promoting food products and animal feeds.     

In vitro antioxidant and anticancer activities of ethanolic extract of selenium-enriched green tea

Selenium-enriched green tea is now being increasingly produced in China and is well known as a bioactive beverage, due to its high content of active components. In this study, the antioxidant and anticancer activities of an ethanolic extract and an aqueous extract of Se-enriched green tea were investigated. The results indicated that the ethanolic extract possessed significantly higher antioxidant activity than the aqueous extract and the positive control α-tocopherol, by both α,α-diphenyl-β-picrylhydrazyl (DPPH) radical-scavenging and ferric thiocyanate (FTC) assays. The ethanolic extract inhibited the proliferation of human cervical adenocarcinoma HeLa cell and possessed a significantly higher antitumour activity than the aqueous extract and the positive control 5-fluorouracil (5-FU), in the dose range of 62.5–250 μg/ml. Moreover, the ethanolic extract could significantly inhibit the growth of lung carcinoma A549 and hepatoma HepG2 in a concentration-dependent manner, with IC₅₀ values of 278.6 μg/ml and 431.6 μg/ml, respectively. Selenium, tea polyphenols and polyphenols constituents, especially epigallocatechin gallate (EGCG), were significantly higher in the ethanolic extract than in the aqueous extract, which were possibly responsible for the higher antioxidant and antitumour activities of the ethanolic extract.