Effect of different lignocellulosic wastes on Hericium americanum yield and nutritional characteristics.

BACKGROUND: The aim of this study was to investigate the possibility of using cottonseed hulls (CSH) and olive press cake (OPC) as new supplement materials for substrate preparation in Hericium americanum cultivation. Some chemical properties of the substrates prepared by mixtures of oak sawdust (OS) with wheat bran (WB), CSH and OPC in different ratios were determined. In addition, the effect of mixtures of OS:CSH and OS:OPC on spawn run time, yield and biological efficiency (BE), average mushroom weight and nutrition content of the fruiting body were compared with the control substrate (8OS:2WB). RESULTS: The yield, BE and average mushroom weight of substrates containing CSH and OPC were higher than the control substrate and increased with an increase in the rate of CSH and OPC in the mixtures. Hericium americanum showed (on a dry weight basis) 8.5-23.7% protein, 9.9-21.2 g kg-1 P, 26.6-35.8 g kg-1 K, 0.63 - 1.33 g kg-1 Mg, 0.19 - 0.23 g kg-1 Ca, 1.34-1.78 g kg-1 Na, 49.5-72.2 mg kg-1 Fe, 6.22-10.11 mg kg-1 Mn, 32.8-82.8 mg kg-1 Zn and 8.6-11.2 mg kg-1 Cu on different growing substrates. The nutritional value of mushrooms was greatly affected by the growing media. CONCLUSION: The results revealed that CSH and OPC could be used as new supplement materials for substrate preparation in H. americanum cultivation. © 2016 Society of Chemical Industry.

Improvement of fruiting body production in Cordyceps militaris by molecular assessment.

Cordyceps militaris is a heterothallic ascomycetous fungus that has been cultivated as a medicinal mushroom. This study was conducted to improve fruiting body production by PCR assessment. Based on single-ascospore isolates selected from wild and cultivated populations, the conserved sequences of α-BOX in MAT1-1 and HMG-BOX in MAT1-2 were used as markers for the detection of mating types by PCR. PCR results indicated that the ratio of mating types is consistent with a theoretical ratio of 1:1 (MAT1-1:MAT1-2) in wild (66:70) and cultivated (71:60) populations. Cross-mating between the opposite mating types produced over fivefold more well-developed fruiting bodies than self- or cross-mating between strains within the same mating type. This study may serve as a valuable reference for artificial culturing of C. militaris and other edible and medicinal mushrooms and may be useful to develop an efficient process for the selection, domestication, and management of strains for industrial-scale production.

Anaerobically digested food waste in compost for Agaricus bisporus and Agaricus subrufescens and its effect on mushroom productivity.

BACKGROUND: Source-separated food waste is increasingly being treated by means of hygienisation followed by anaerobic digestion. The fibrous digester residue (digestate) is a potential mushroom substrate, while heat from the biogas can provide steam for the cultivation process. Using bag experiments the present study explored digestate as a full substitute for chicken manure conventionally used in mushroom composts. RESULTS: After mixing, a rapid temperature development in the compost was stimulated by a small amount of chicken manure, as aerobic microbial seeding. Mechanical elimination of lumps was essential for full mycelial colonisation. Three straw digestate composts had Agaricus bisporus mushroom yields above 370 g kg⁻¹ substrate. The optimal compost water content was 600 g kg⁻¹ at inoculation, and high digestate content (up to 500 g kg⁻¹ by dry weight) did not affect yield for this species. High yields of A. subrufescens (200 g kg⁻¹) were related to drier composts of lower digestate content (more straw) and lower pH values at inoculation. CONCLUSION: Digestate successfully substituted chicken manure in straw composts without affecting mushroom yields for both species. There were no clear differences between straw digestate and control composts in terms of mushroom dry matter, size, nitrogen or ash content.

Mercury in European Blushers, Amanita rubescens, mushrooms and topsoils: bioconcentration potential and intake assessment.

Total mercury content has been determined in fruiting bodies of European Blushers and topsoils collected from 11 sites across Poland in 2006-2008. Mercury analysis was carried out using a validated analytical method and cold-vapour atomic absorption (CV-AAS). The European Blusher effectively accumulated mercury in fruiting bodies. The mean values of total mercury in caps of European Blushers from background (uncontaminated) areas were from 0.22 to 1.0 (0.067-3.2) and in stipes from 0.16 to 0.65 (0.071-2.7) µg/g dry weight. In topsoil beneath to fruiting bodies, the median Hg concentration at 10 sites in Northern Poland varied between 0.030 and 0.072 (0.0096-0.19) µg/g dw, and in one site in Southern Poland was 0.20 (0.079-0.34) µg/g dw. Data on Hg in European Blushers from different countries were reviewed. The mean concentrations of total Hg in caps of European Blushers from two "pristine" sites in northern part of Poland were ∼1.0 µg/g dw. A meal made with 300-500 g of fresh caps of European Blushers collected at such sites (assuming 90% water content in caps) can result in Hg intake of 0.0003-0.0005 mg Hg/kg bm (assuming a 60 kg bm), which is a dose equipotent to a new provisional tolerable weekly intake (PTWI) value set for inorganic Hg.

Influence of calcium and silicon supplementation into Pleurotus ostreatus substrates on quality of fresh and canned mushrooms.

Supplements of gypsum (calcium source), pumice (silicon source) and pumice sulfate (silicon and calcium source) into substrates for oyster mushrooms (Pleurotus ostreatus) were searched for their effects on production as well as qualities of fresh and canned mushrooms. The addition of pumice up to 30% had no effect on total yield, size distribution and cap diameters. The supplementation of gypsum at 10% decreased the total yield; and although gypsum at 5% did not affect total yield, the treatment increased the proportion of large-sized caps. High content (>10%) of pumice sulfate resulted in the lower yield. Calcium and silicon contents in the fruit bodies were not influenced by supplementations. The centrifugal drip loss values and solid content of fresh mushrooms, and the percentage of weight gained and firmness of canned mushrooms, cultivated in substrates supplemented with gypsum, pumice and pumice sulfate were significantly (p≤0.05) higher than those of the control. Scanning electron micrographs revealed the more compacted hyphae of mushroom stalks supplemented with silicon and/or calcium after heat treatment, compared to the control. Supplementation of P. ostreatus substrates with 20% pumice was the most practical treatment because it showed no effect on yield and the most cost-effective.

Cultivation and bioactivity assessment of Grifola frondosa fruiting bodies on olive oil press cakes substrates.

Grifola frondosa, a medicinal and edible mushroom, was cultivated on substrates composed of olive oil press cakes with different supplements. Crude extracts were prepared from mature fruiting bodies and tested for their capacity to stimulate splenocyte proliferation. Two wild-growing fruiting bodies were extracted for comparison. Olive oil press cakes reduced the mushroom yield, and the best biological efficiency was obtained on substrates supplemented with wheat bran and without olive oil press cakes. All extracts were capable of inducing splenocyte proliferation and were half as effective as the positive control (6.0 microg/mL phytohaemagglutinin). No correlation between substrate composition and bioactivity could be established. Extracts from wild-growing G. frondosa were superior to cultivated ones in respect to biological activity.