Vacuum-soaking of wood chip shiitake (<Emphasis Type="Italic">Lentinula edodes</Emphasis>) logs to reduce soak time and log weight variability and to stimulate mushroom yield

Synthetic logs were vacuum-soaked or regular-soaked to determine the effects of soaking on yield and mushroom size, log weight variability and water distribution within the log. Yields (g/log) from substrates vacuum-soaked were higher by 26.7%, 18.6% and 35.8% (mean = 27.2%) for crops I, II and III, respectively, when compared with regular-soaked. However, mushroom size averaged only 11.2 g for vacuum-soaked logs vs 17 g for regular-soaked logs (51.8% larger for regular-soaked). The time required for vacuum-soaking logs was generally less than 3 min, compared with regular-soaking times ranging over 3-15 h. Water tended to accumulate more in the outside zone in the vacuum-soaked logs, compared with regular-soaked logs. Mean moisture contents for crops I and II for outside, middle and interior zones of vacuum-soaked logs were 66%, 47.5% and 42.2%, respectively, while regular-soaked logs for the same zones were 62.4%, 52.1% and 50.9%, respectively. Vacuum-soaked log weights had lower standard deviations than weights for regular-soaked logs in four out of six soaks, indicating a more uniform soaking process.     

Forest farming of shiitake mushrooms: An integrated evaluation of management practices

Two outdoor shiitake (Lentinula edodes) cultivation experiments, established in Missouri USA in 1999 and 2000, produced mushrooms in 2000–2005. We examined shiitake production in response to substrate species, inoculum form, inoculum strain, and inoculation timing, using total mushroom weight per log as the primary response variable with log characteristics as covariates. The significantly greater mushroom weight produced by sugar maple logs compared with white or northern red oak was attributable to the higher proportion of undiscolored wood volume in the maple logs, rather than to bark thickness or log diameter. The “wide temperature range” shiitake strain produced significantly greater yield compared with the “warm” or “cold” weather strains. Both the wide-range and warm-weather strains were stimulated to fruit by significant rain events, while the cold-weather strain was responsive to temperature. Inoculation with sawdust spawn gave significantly greater yield than colonized wooden dowels or pre-packaged “thimble” plug inoculum. The second and third full years following inoculation were the most productive.     

The influence of spawn type and strain on yield, size and mushroom solids content of Agaricus bisporus produced on non-composted and spent mushroom compost

Two crops of Agaricus bisporus (J. Lange) Imbach were grown on mixtures of non-composted substrate (NCS)/spent mushroom compost (SMC) or pasteurized Phase II compost (control). NCS consisted of oak sawdust (28% oven dry wt), millet (29%), rye (8%), peat (8%), ground alfalfa (4%), ground soybean (4%), wheat bran (9%), and CaCO3 (10%). Substrates included 25/75 NCS/SMC, 50/50 NCS/SMC, and 75/25 NCS/SMC, NCS and Phase II compost. Spawn types and strains were evaluated for their effects on yield, biological efficiency (BE), size and mushroom solids content. Spawn types included millet, casing inoculum (CI), 50/50 CI/millet, or NCS while mushroom strains were of the brown or hybrid off-white variety (U1 type). Mushroom yields and BEs on substrate mixtures of NCS and SMC were comparable to non-supplemented Phase II compost. The highest yield (12.8 kg/m2) and BE (70.9%) were produced on a substrate mixture of 50/50 NCS/SMC and spawn type NCS. Mushroom solids content (7.1%) was highest from the brown strain produced on a 50/50 mixture of NCS/SMC.     

Forest farming of shiitake mushrooms: Aspects of forced fruiting

Three outdoor shiitake (Lentinula edodes (Berk.) Pegler) cultivation experiments were established during 2002–2004 at the University of Missouri Horticulture and Agroforestry Research Center, in central Missouri. Over three complete years following a year of spawn run, we examined shiitake mushroom production in response to the temperature of forcing water, inoculum strain, substrate host species and physical orientation of the log during fruiting. Forcing compressed the period of most productive fruiting to the two years following spawn run. Further, chilled forcing water, 10–12 °C, significantly enhanced yield, particularly when ambient air temperatures were favorable for the selected mushroom strain. The temperature of water available for force-fruiting shiitake logs depends on geographic location (latitude) and source (i.e., farm pond vs. spring or well water). Prospective growers should be aware of this effect when designing their management and business plans.     

Ground wheat straw as a substitute for portions of oak wood chips used in shiitake (Lentinula edodes) substrate formulae

Oak woodchips, used for production of shiitake Lentinula edodes (Berk) Pegler, are increasingly difficult to obtain due to dwindling supplies. We investigated the effect of adding ground wheat straw as a substitute for portions of oak woodchips in substrate formulae on mushroom yield and size. We also determined the effect of mushroom cropping on relative feed value (RFV) by chemical analysis of the substrate at spawning (AS) and after cropping (AC). Three formulae containing 0%, 8% and 16% ground wheat straw and 52%, 44% and 36% oak sawdust, respectively, were bulk pasteurized (111 degrees C for 20 min) in an autoclaving mixer, subjected to spawn run (21 d), browning (28 d) and a production cycle of three breaks (38 d). Mean (4 crops) mushroom yields were 11% higher when 8% wheat straw was used in the medium and 19% higher when 16% wheat straw was substituted for portions of oak sawdust. There were no significant differences in mushroom sizes between any of the treatments. Relative feed values of shiitake substrates AC increased more dramatically as more wheat straw was added to the formulae. Using mature alfalfa (full bloom) as a base value of 100%, RFVs for substrate AS were 98%, 92%, and 92% for 0%, 8% and 16% straw, respectively; RFVs AC were 118%, 120% and 133%, respectively. Substrate AC containing 16% straw had a RFV comparable to corn silage (well-eared). Fat contents of the substrates decreased by 50-62% AC, whereas potassium contents decreased by 40%. Use of ground wheat straw in synthetic medium would not only increase mushroom yield by up to 19%, but may help alleviate periodic shortages of oak sawdust. In addition, growers would avoid the added expense of aging the wheat straw (for 8-12 week) as is typically done for oak sawdust in the industry. This is the first report of RFVs for spent shiitake substrate (SSS) predicting its excellent potential for use as animal feed.     

Supplementation of first break mushroom compost with hydrolyzed protein, commercial supplements and crystalline amino acids

Three mushroom (Agaricus bisporus) crops (Crops 1, 2, 3) were grown to evaluate the effects of re-supplementing “spent” first break compost [mushroom compost (MC)] on mushroom yield. Mushrooms were produced for one break at the Mushroom Test Demonstration Facility, the casing layer was removed and the MC was re-supplemented with hydrolyzed protein, commercial supplements and crystalline amino acids and then re-cased at the Mushroom Research Center. Sixteen supplements, including five crystalline amino acids, one amino acid blend, one egg white and four hydrolyzed proteins, Micromax^® (a micronutrient containing nine minerals) and four commercial supplements were evaluated for their effect on mushroom yield and biological efficiency. In Crop 1, mushroom yields were stimulated (49–61%) when MC was re-supplemented with 3.6% (dry wt) Pro-Fam^® H200 FG hydrolyzed soy protein, Remo’s commercial supplement, l-isoleucine (ile), egg white protein, amino blend HLA-198 and hydrolyzed whey. Significant yield reductions were observed for MC re-supplemented with 3.6% l-tyrosine, dl-methionine or l-arginine compared to the non-supplemented control. In Crop 2, mushroom yield ranged from a high of 31.3 kg/m² on MC supplemented with 3.3% Remo’s + 0.3% ile (oven dry MC) to a low of 22.6 kg/m² on non-supplemented (control) MC (38.5% difference). In Crop 3, a response surface model was used in an attempt to optimize combinations of Remo’s commercial supplement, ile and Micromax. The response surface solution for optimal yield was 2.9% Remo’s, 0.16% ile and 0.4% Micromax. Because many of the products tested performed equally well but varied substantially in their amino acid profiles, A. bisporus appears adaptable to different supplements containing both balanced and unbalanced amino acid contents, especially those rich in the branched chain amino acids. Development and improvement of supplements designed specifically for MC may allow further increases in productivity. Double cropping would ultimately lower the cost of mushroom production by reducing labor, raw materials and time required to prepare fresh Phase II compost.     

Effects of spawn,supplement and phase II compost additions and time of re-casing second break compost on mushroom (Agaricus bisporus) yield and biological efficiency

Three cropping experiments (0710, 0803 and 0805) were conducted to determine the effect of adding spawn, various levels of delayed release nutrient, and phase II compost to 2nd break mushroom compost (2BkC) on mushroom yield and biological efficiency (BE). We also investigated the effect of delaying time of re-casing non-supplemented and supplemented 2BkC on mushroom yields and BEs. The addition of 14.6% spawn to nutrient-supplemented 2BkC (w.w./d.w) increased yield by 11.1% over the control (no spawn) but did not affect BE. The addition of delayed release supplements to 2BkC increased maximum yields by 29–54%, depending on the treatment. Substitution of 15% phase II compost in 2BkC (15/85) did not significantly affect mushroom yields. However, use of 15% phase II compost in 2BkC increased the response of the mixture to delayed release supplement. Yield response to increasing levels of supplement was greater in the 15/85 mixture compared to 100% 2BkC. Yields also increased as time of re-casing was delayed up to 10 days. Mushroom yields increased approximately 2.1% for each day re-casing was delayed. Overall yields were generally higher from commercial 2BkC compared to 2BkC originating from the Penn State Mushroom Research Center (MRC) probably due to nitrogen (N) content of the 2BkC. Nitrogen content in commercial 2BkC (Crop 0805) was 3% while N content in 2BkC from Crops 0710 and 0803 was 2.2% and 2.1%, respectively. By optimizing supplement levels and adding 15% phase II compost to commercial 2BkC, or by delaying casing by 5–10 days, it was possible to obtain BEs that were equivalent to supplemented phase II compost.     

Enhanced Yield of Shiitake by Saccharide Amendment of the Synthetic Substrate

Three experiments were performed to determine the effect of selected saccharides on mushroom yield and basidiome size of shiitake (Lentinula edodes) when grown on a synthetic substrate. Substrate formulations of sawdust, wheat bran, and millet were nonamended or amended with sucrose, fructose, or glucose. Addition of sucrose (0.6 to 1.2% [dry weight]) to the substrate stimulated mushroom yield by 11 to 20% or more. Addition of fructose at 1.2% and glucose at 0.6% resulted in similar yield increases. Most of the yield increase occurred on the first break. The substrate amended with 1.2% sucrose tended to have a more synchronous maturation for the second break resulting in fewer days when mushrooms were harvested.     

Heat treatment of wheat straw by immersion in hot water decreases mushroom yield in Pleurotus ostreatus

BackgroundThe oyster mushroom, Pleurotus ostreatus, is cultivated worldwide. It is one of the most appreciated mushrooms due to its high nutritional value. Immersion of the substrate in hot water is one of the most popular and worldwide treatment used for mushroom farmers. It is cheap and easy to implement.AimsTo compare the yields obtained during mushroom production of P. ostreatus using different pre-treatments (immersion in hot water, sterilization by steam and the use of fungicide) to determine if they influence mushroom crop.MethodsFour different treatments of substrate (wheat straw) were carried out: (i) immersion in hot water (IHW); (ii) steam sterilization; (iii) chemical; and (iv) untreated. The residual water from the IHW treatment was used to evaluate the mycelium growth and the production of P. ostreatus.ResultsCarbendazim treatment produced highest yields (BE: 106.93%) while IHW produced the lowest BE with 75.83%. Sugars, N, P, K and Ca were found in residual water of IHW treatment. The residual water increased the mycelium growth but did not increase yields.ConclusionsWe have proved that IHW treatment of substrate reduced yields at least 20% when compared with other straw treatments such as steam, chemical or untreated wheat straw. Nutrients like sugars, proteins and minerals were found in the residual water extract which is the resultant water where the immersion treatment is carried out. The loss of these nutrients would be the cause of yield decrease. Alternative methods to the use of IHW as treatment of the substrate should be considered to reduce economical loss.     

Comparative study on the mycelial growth and yield of Ganoderma lucidum (Curt.: Fr.) Karst. on different lignocellulosic wastes

The aim of this study was to examine the possibility of using wheat straw (WS), cottonseed meal (CSM), sunflower meal (SFM), soybean straw (SBS) and bean straw (BS) as basal substrates in Ganoderma lucidum cultivation instead of oak (OS) and poplar (PS) sawdusts. In the study, effects of different growing substrates on spawn running period, yield and biological efficiency (BE) of G. lucidum were determined. Moreover, possible correlations among productivity and lignocellulosic content of substrates were assessed. Average spawn run period varied between 14.2 and 18.2 d. Total yields of G. lucidum grown on different substrates ranged from 28.6 g/kg to 86.1 g/kg, while the corresponding values for BE varied between 8.9%–24.7%. The highest yield and BE was exhibited by the OS followed by PS substrate. CSM gave the lowest yield and BE. Spawn running time was found to be positively correlated to nitrogen content of the substrates (r² = 0.918) and negatively correlated to cellulose and hemicellulose content of substrate (r² = −0.927 and r² = −0.838, respectively). The total mushroom yield was correlated negatively to nitrogen content of the substrates (r² = −0.850) and positively correlated to C:N ratio (r²=0.915). Moreover, there is a strong positive correlation between mushroom yield and cellulose and lignin content of the substrates (r² = 0.794 and r²= 0.879). According to results, G. lucidum had a preference for substrates containing a high amount of cellulose and and lignin, and having a low amount of N and high cellulose:lignin ratio. Furthermore, SBS, WS and BS may be suggested as alternative basal substrates for cultivation of G. lucidum.     

Comparative study of mycelia growth and sporophore yield of Auricularia polytricha (Mont.) Sacc on selected palm oil wastes as fruiting substrate

The potential for using agricultural and industrial by-products as substrate for the production of the edible mushroom, Auricularia polytricha, was evaluated using several formulations of selected palm oil wastes mixed with sawdust and further supplemented with selected nitrogen sources. The best substrate formulations were sawdust (SD) mixed with oil palm frond (OPF; 90:10) added with 15 % spent grain (SG) and sawdust mixed with empty fruit bunch (EFB; 50:50) added with 10 % spent grain (SG) with mycelia growth rate of 8 mm/day and 7 mm/day respectively. These two substrate formulations were then subjected to different moisture content levels (65 %, 75 % and 85 %). Highest total fresh sporophore yield at 0.43 % was obtained on SD?+?OPF (90:10)?+?15 % SG at 85 % moisture content, followed closely by SD?+?EFB (50:50)?+?10 % SG with 0.40 % total yield, also at 85 % moisture content. Each of the substrate formulations at 85 % moisture content gave the highest biological efficiency (BE) at 288.9 % and 260.7 %, respectively. Both yield and biological efficiency of A. polytricha on these two formulations were almost three times higher when compared to sawdust substrate alone, thus proving the potential of these formulations to improve yield of this mushroom.     

Effects of nutrient supplements on biological efficiency, quality and crop cycle time of maitake (Grifola frondosa)

The effects of various combinations of wheat bran, rye and millet (at 20% and 30% of total dry substrate wt) on crop cycle time, biological efficiency (BE) and mushroom quality were evaluated for a commercially used isolate of Grifola frondosa (maitake). Supplements were combined with a basal ingredient of mixed oak (primarily red oak) sawdust, and the resulting mixture was pasteurized, cooled, inoculated and bagged with an autoclaving mixer. Times to mushroom primordial formation and mushroom harvest were recorded, and mushroom quality was rated on a scale of 1-4, where 1 was the highest quality and 4 was the lowest quality. The combinations of 10% wheat bran, 10% millet and 10% rye (BE 47.1%, quality 1.8 and crop cycle 12 weeks) and 10% wheat bran plus 20% rye (BE 44%, quality 1.7 and crop cycle 10 weeks) gave the most consistent yields and best basidiome quality over time.     

Comparative study on the growth and yield of<Emphasis Type="Italic"> Pleurotus ostreatus</Emphasis> mushroom on different lignocellulosic by-products

Eight lignocellulosic by-products were evaluated as substrates for cultivation of the oyster mushroom, Pleurotus ostreatus (Jacq. ex. fr) Kummer. The yields of mushroom on the different substrates were 183.1, 151.8, 111.5, 87.8, 49.5, 23.3, 13.0 and 0.0 g for composted sawdust of Triplochiton scleroxylon, rice straw, banana leaves, maize stover, corn husk, rice husk, fresh sawdust, and elephant grass, respectively. The biological efficiency (BE) followed the same pattern and ranged from 61.0% for composted sawdust to 0.0% for elephant grass. The yield of mushroom was positively correlated to cellulose (r ² =0.6), lignin (r ² =0.7) and fibre (r ² =0.7) contents of the substrates. Based on the yield and BE of the substrates tested, rice straw appeared to be the best alternate substrate for growing oyster mushrooms. Electronic Publication     

Cultivation of the Dible Mushroom Lentinula edodes (Shiitake) in Pasteurized Wheat Straw – Alternative Use of Georthermal Energy in Mexico

Five edible Lentinula edodes strains were evaluated. The mushrooms were cultivated on a wheat straw substrate that was previously pasteurized by immersion in water heated by residual geothermal vapor, which was also used to warm incubation and production rooms. Finely chopped wheat straw (Triticum aestivum L.) was pasteurized and then spawned with supplemented spawn capable of supplying nutrients and enriching the substrate, with the expectation of yield improvement. The samples were incubated for 60 days before the production started and thus, the mushrooms produced had pileus diameters ranging from 5 to 20 cm. The yields fluctuated from 6.2 to 13.9 % (fresh weight of mushrooms/fresh weight of substrate). Biological efficiency ranged from 24.8 to 55.6 % (fresh weight of mushrooms/dry weight of substrate), while the production rate reached varied from 0.19 to 0.55 % (biological efficiency/production time starting from inoculation). The cultivation system evaluated here offers the possibility of lowering production costs by cultivating the mushroom on easily obtainable substrate and shortening the culture cycle. The efficiency of this use of geothermal energy and supplemented spawn for shiitake mushroom cultivation on non‐sterilized substrates was proven.     

Recycling of spent shiitake substrate for production of the oyster mushroom,Pleurotus sajor-caju

Pleurotus sajor-caju was produced on a basal medium containing spent shiitake substrate plus 10% wheat bran and 10% millet. An analysis of the fibrous composition of the spent shiitake substrate revealed that 85% of the original hemicellulose, 44% of the original cellulose and 77% of the original lignin was not consumed during production of a full crop (78% biological efficiency) of shiitake (63-day harvest period). To produce P. sajor-caju, the spent shiitake substrate was ground, air dried, supplemented, pasteurized with live steam and spawned. Highest yields (79% biological efficiency) of P. sajor-caju were obtained by supplementing the spent shiitake basal medium with 12% soybean and 1% CaCO₃. Increases in percentage biological efficiency and mushroom size were positively correlated with increasing levels of CaCO₃ added to the basal medium.     

The commercial exploitation of the white rot fungus Lentinula edodes (shiitake)

The Japanese wood mushroom, Lentinula edodes, can be cultivated under UK climatic conditions using extensive cultivation systems adapted from traditional growing methods developed in Japan and Taiwan. As well as producing a desirable and high value food product, cultivation offers a viable alternative enterprise for farmers. The growing methods described could provide incentives for the management of broad-leaved woodland in Britain with consequent conservation benefits. Four different strains of Lentinula edodes were grown on oak logs under natural environmental conditions below the woodland canopy and fruited in polyethylene tunnels. Yields ranged from 0.5–0.9 kg wet weight shiitake per cordwood log per year over a three year fruiting period.     

Yield,size, and mushroom solids content of <Emphasis Type="Italic">Agaricus bisporus</Emphasis> produced on non-composted substrate and spent mushroom compost

Three crops of Agaricus bisporus were grown on non-composted substrate (NCS), spent mushroom compost (SMC), a 50/50 mixture of NSC/SMC, or pasteurized Phase II compost. NCS consisted of oak sawdust (28% oven dry wt), millet (29%), rye (8%), peat (8%), ground alfalfa (4%), ground soybean (4%), wheat bran (9%) and CaCO₃ (10%). Substrates were non-supplemented or supplemented with Target^® (a commercial delayed release nutrient for mushroom culture) or soybean meal at spawning or casing, or with Micromax^® (a mixture of nine micronutrients) at spawning. Mushroom yield (27.2 kg/m²) was greatest on a 50/50 mixture of NCS/SMC supplemented with 10% (dry wt) Target^® at casing. The same substrate supplemented with Target^® at spawning yielded 20.1 kg/m². By comparison, mushroom yield on Phase II compost supplemented at casing or at spawning with Target^® was 21.6 kg/m² and 20.6 kg/m², respectively. On NCS amended with 0.74% or 0.9% Micromax^® at spawning, yields increased by 51.8% (12.9 kg/m²) and 71.8% (14.6 kg/m²), respectively, over non-amended NCS (8.5 kg/m²). Conversely, mushroom yields were not affected when Micromax^® was added to a 50/50 mixture of NCS/SMC. Mushroom solids content was higher in mushrooms harvested from NCS amended with 0.74% Micromax^® (9.6%) compared to non-amended NCS (8.3%).     

Supplementation of 2nd break mushroom compost with isoleucine, leucine, valine, phenylalanine, Fermenten® and SoyPlus®

Three mushroom (Agaricus bisporus) crops (Crops 1, 2, 3) were grown to evaluate the effects of re-supplementing “spent” mushroom compost (MC) with the crystalline amino acids isoleucine (ile), leucine (leu), valine (val) and phenylalanine (phe) singly or in combination with Fermenten^® or SoyPlus^® on mushroom yield. Fermenten^® is a rumen fermentation enhancer while SoyPlus^® is a commercial delayed release mushroom nutrient. The most important single amino acid found for stimulating mushroom yield from 2nd break MC was ile. Crystalline ile added to 2nd break MC at 3.6% (dry wt) increased mushroom yields by 28.3% and 68.7% (average 48.5%) in Crops 1 and 2, respectively, compared to the non-supplemented control. In Crop 3, the addition of 5% or 10% ile to Fermenten^® and SoyPlus^® (3.6% total combined dry wt) did not significantly improve mushroom yield over treatments containing Fermenten^® or SoyPlus^® (3.6% total dry wt) alone. However, mixtures of equal quantities of Fermenten^®, ile and val significantly increased yield over Fermenten^® alone. Use of ile and val as supplements to stimulate mushroom yield from 2nd break MC is not economically viable because these amino acids are not commercially available at feed grade prices.     

Characterization of vitamin B12 compounds in the fruiting bodies of shiitake mushroom (Lentinula edodes) and bed logs after fruiting of the mushroom

This study determined the vitamin B₁₂ content in commercially available dried fruiting bodies of shiitake mushroom, Lentinula edodes. The vitamin B₁₂ contents in dried donko-type fruiting bodies with closed caps (5.61 ± 3.90 μg/100 g dry weight), did not significantly differ from those of dried koushin-type fruiting bodies with open caps (4.23 ± 2.42 μg/100 g dry weight). The bed logs after fruiting of the mushroom also contained the vitamin B₁₂ levels similar to that in the dried shiitake fruiting bodies. To determine whether the dried shiitake fruiting bodies and their bed logs contained vitamin B₁₂ or other corrinoid compounds that are inactive in humans, we purified corrinoid compounds using an immunoaffinity column and identified vitamin B₁₂ using vitamin B₁₂-dependent Escherichia coli 215 bioautograms and liquid chromatography-electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) chromatograms. Dried shiitake fruiting bodies rarely contained an unnatural corrinoid vitamin B₁₂[c-lactone] that is inactive in humans. Given that shiitake mushroom lacks the ability to synthesize vitamin B₁₂ de novo, the vitamin B₁₂ found in dried shiitake fruiting bodies must have been derived from the bed logs.     

Adapting substrate formulas used for shiitake for production of brown Agaricus bisporus

A pasteurized, non-composted substrate (basal mixture) consisting of oak sawdust (28%), millet (29%), rye (8%), peat (8%), alfalfa meal (4%), soybean flour (4%), wheat bran (9%), and CaCO3 (10%) was adapted from shiitake culture to produce the common cultivated mushroom (brown; portabello), Agaricus bisporus. Percentage biological efficiency (ratio of fresh mushroom harvested/oven-dry substrate weight, %BE) ranged from a low of 30.1% (when wheat straw was substituted for sawdust) to 77.1% for the basal mixture. Special, high gas-exchange bags were required to optimize mycelial growth during spawn run. Our formula may allow specialty mushroom growers to produce portabello mushrooms on a modified, pasteurized (110 degrees C for 20 min) substrate commonly used for shiitake production without the added expense of compost preparation.