Spawn Running Time Research Articles

Comparative studies on the cultivation, yield, and nutritive value of an edible mushroom, Pleurotus tuber-regium (Rumph. ex Fr.) Singer, grown under different agro waste substrates.

In the present study, Pleurotus tuber-regium (Rumph. ex Fr.) Singer collected from Keeriparai forest of Kanyakumari district, South India was cultivated using environmentally benign, low-cost agricultural waste residues (paddy straw, sugarcane bagasse, rice husk, and sawdust) as growth substrates. The main goal of this study was to assess the cultivation, yield, and nutritional value of P. tuber-regium fruiting bodies grown under different growth substrates. Spawn running time and time for primordia formation were found to be shorter in mushroom growing with paddy straw substrate compared to sawdust and sugarcane bagasse. A quick spawn run time was observed in paddy straw substrate (12 ± 1 day) followed by sugarcane bagasse (15 ± 1 day) and sawdust (23 ± 1 day). The primordia was well developed in the macrofungus grown with paddy straw substrate on 18 ± 1 day followed by sugarcane bagasse (22 ± 1 day) and sawdust (32 ± 1 day). Significantly higher yield of fruiting bodies with increased contents of protein and carbohydrate and low level of fat was obtained when P. tuber-regium was cultivated with paddy straw substrate. While, cultivation of P. tuber-regium in sawdust and sugarcane bagasse resulted in increased contents of K, Na, Ca, and Mg along with highest energy value. On the other hand, rice husk did not support the cultivation of this macrofungus. Therefore, it is of significant interest to initiate the commercial production of this macrofungus so as to fight against the problems of malnutrition found in few African and south Asian countries.

Production of oyster mushroom (Pleurotus ostreatus) from some waste lignocellulosic materials and FTIR characterization of structural changes

In this study, oyster (Pleurotus ostreatus) mushroom was cultivated from hazelnut branches (HB) (Corylus avellana L.), hazelnut husk (HH), wheat straw (WS), rice husk (RH) and spent coffee grounds (CG). Hazelnut branch waste was used for the first time in oyster mushroom cultivation. In the study, mushrooms were grown by preparing composts from 100 to 50% mixtures of each waste type. Yield, biological activity, spawn run time, total harvesting time and mushroom quality characteristics were determined from harvested mushroom caps. In addition, chemical analysis of lignocellulosic materials (extractive contents, holocellulose, α-cellulose, lignin and ash contents) were carried out as a result of mushroom production and their changes according to their initial amounts were examined. In addition, the changes in the structure of waste lignocellulosic materials were characterized by FTIR analysis. As a result of the study, 172 g/kg yield was found in wheat straw used as a control sample, while it was found as 255 g/kg in hazelnut branch pruning waste. The highest spawn run time (45 days) was determined in the compost prepared from the mixture of hazelnut husk and spent coffee ground wastes. This study showed that HB wastes can be used for the cultivation of oyster mushroom (P. ostreatus). After mushroom cultivation processes, holocelulose and α-cellulose content rates decreased while ash contents increased. FTIR spectroscopy indicated that significant changes occurred in the wavelengths regarding cellulose, hemicellulose and lignin components. Most significant changes occurred in 1735, 1625, 1510, 1322 and 1230 wavelengths.

Utilization of Agricultural and Forestry by-Products in Ganoderma lucidum (Curt.: Fr.) P. Karst. Production

The aim of the study was to evaluate the use of some local agricultural and forestry by-products as Ganoderma lucidum growing subsrate. In the study, 8 different growing media prepared by mixing agricultural and forestry wastes such as oak sawdust (OS), poplar sawdust (PS), wheat straw (WS), wood chips (WCH), green almond hulls (AH) and green walnut hulls (GWH) alone or in different proportions, were used for G. lucidum cultivation and the effects of these substrates on spawn run time (SRT), days to pinhead initiation (DPI), days to the first harvest (DFH), yield (g/kg) and biological efficiency (BE%) were investigated. The results demonstrated that spawn run time (SRT) of G. lucidum was shorter in PS and WS:GWH12.5 (19.7 days and 20.8 days) as compared to other substrates and mixtures (22.2-28.5 days). The pinheads emerged in substrates between 43th- 49th days and the fruiting bodies were collected between 80.3 -93.5 days after the spawning. Total fresh mushroom yield and BE(%) varied from 71.39 to 110.10 g/kg of substrate and from 21.0% to 31.46, respectively. Moreover, PS substrate produced fruitbody also earlier compared with the other investigated substrates. The study revealed that although higher total yields were obtained by sawdust substrates, considering the difficulty of finding sawdust in some areas, WS and the mixture of WS and GHW (87.5:12.5%) could be also successfully used inof G. lucidum production.

Yenilebilir mantar (Pleurotus ostreatus) için tahılsız misel geliştirilmesi: D-optimal karışım tasarımı yaklaşımı

Objective: The objective of this study was to develop a non-grain spawn formulation for Pleurotus ostreatus with the D-optimal mixture design approach. The developed spawn was compared with the traditionally used grain spawn in terms of spawn running time and biological efficiency. Material and Methods: Non-grain spawn was produced in 25 different formulations using wheat bran, poplar sawdust, perlite, CaCO3, CaSO4 components. In addition, oat spawn containing 1% CaSO4 and 0.5% CaCO3 from cereals was used as the control group. Spawn running times and the biological efficiencies of the samples were determined. Results: The optimum mixing ratios for wheat bran, poplar sawdust, perlite, CaCO3, and CaSO4 used in the formulation of non-grain spawn production were determined as 11.44%, 28.87%, 50.74%, 5.89%, and 3.07%, respectively. The spawn running time of the improved non-grain spawn produced according to the above formulation was shortened by 20.16% as compared to the grain-derived spawn. This shows that the non-grain as one of the two different spawn production methods is technologically superior. Conclusion: In the leading countries in mushroom production, new technologies and formulations are being developed day by day to shorten the spawn running time and increase biological efficiency and mushroom yield. It is thought that this study will contribute to the development of spawn technology, which is an essential input in mushroom cultivation.

Cultivation of Oyster Mushroom (Pleurotus ostreatus) from Agro-waste and Dry Leaf Litter in used Plastic Bottles: Community Waste Management Model targeting Stubble and Dry leaf burning

In recent years, solid waste management has developed from early approaches of burning or dumping to reuse, recycle, regain, and retain various alternative technologies. The present study aims at developing an effective community waste management model with a solution to multiple issues. It aims to provide an alternative to widespread stubble burning, burning dry leaf litter and promoting plastic reuse. The present novel technology involved the cultivation of Oyster Mushroom (Pleurotus ostreatus) in used plastic bottles to convert agricultural and urban waste into a highly nutritional end product. In this direction, the effect of different wheat straw and dry leaves’ ratios was assessed on the spawn run time, primordial formation, final harvesting time, mean yield per plastic bottle, and the % biological efficiency per gram of the substrate. Both the combinations of L30:WS70 and L50:WS50 represented ideal options for using the two waste substrates to cultivate the mushroom species. This model will help recycle agro-waste and serve as an effective method of generating nutritious food for fighting food security while decreasing the plastic load and trash thrown for disposal.

Use of sugar mill wastewater for Agaricus bisporus cultivation: prediction models for trace metal uptake and health risk assessment.

This study explored the sustainable use of treated sugar mill wastewater (SMW) to cultivate the White button (Agaricus bisporus J.E. Lange) mushroom and the attendant risk of trace metals accumulated in the fruiting bodies. The wheat straw substrate was loaded with a normal water supply and different doses of SMW to enhance its moisture and nutrient contents. The impact of the SMW amendment on A. bisporus yield, biological efficiency, and spawn-running time was assessed. Furthermore, the substrate properties (pH, organic matter, total nitrogen, total phosphorus, etc.) based prediction models for trace metal uptake by A. bisporus fruiting bodies were developed using multiple linear regression (MLR) and artificial neural network (ANN) approaches. The results showed that maximum A. bisporus yield (158.42 ± 8.74 g/kg fresh substrate), biological efficiency (105.61 ± 3.97%), and minimum time of spawn-running (15 days) were observed in 75% SMW enrichment. For the prediction of Cd, Cu, Cr, Fe, Mn, and Zn trace metal uptake, the ANN models showed better performance in terms of R2 (> 0.995), root means square error (RMSE < 0.075), model efficiency (ME > 0.99), and model normalized bias (MNB < 0.009), as compared with those of MLR models with R2 (0.972), RMSE (< 0.441), ME (> 0.96), and MNB (< 0.034), respectively. On the other hand, the target hazard quotient (THQ) showed no significant health risk associated with the consumption of trace metal-contaminated A. bisporus in both adult and child groups. Thus, the findings of this study present a novel, safe, and sustainable method of A. bisporus cultivation along with treated agro-based wastewater management.

The use of phenolic-rich agricultural wastes for Hericium erinaceus and Lentinula edodes cultivation and its effect on yield performance

Objective: This research investigated that the use of four selected agro-waste materials rich in phenolic content on cultivation of Hericium erinaceus and Lentinula edodes mushrooms. Material and Methods: For this purpose, these wastes were comparatively evaluated regarding their suitability for mycelial growth, yield and biological efficiency (BE), of these mushroom species. The oak sawdust (OS) basal medium was mixed with 20% grape pomace (GP), green walnut hull (GWH), olive press cake (OPC), and tea waste (TW) for the production of these species in factorial experiments based on a completely randomised design with ten replications. Results: For both H. erinaceus and L. edodes, the shortest spawn running time (22.4 and 45.4 days, respectively) and the highest yield (225.0 g kg-1 and 282.9 g kg-1, respectively) were found using GP. The BE of H. erinaceus and L. edodes were varied between 15.2-64.3% and 36.0-70.7% , respectively. Conclusion: GP, TW and OPC were seen as promising alternative substrates for the cultivation of these species. Moreover, for the effective utilisation and profitable disposal of green walnut hulls, further research is needed. to test their performance for the cultivation of other mushroom species.

Isolation of bacteria at different points of Pleurotus ostreatus cultivation and their influence in mycelial growth

Pleurotus ostreatus is one of the most cultivated edible mushrooms worldwide and few approaches have been done to analyze bacterial influence during its cultivation. Therefore, bacteria from commercial spawn, mycelial-colonized straw and fruiting bodies from healthy productive samples were counted, isolated and tested for their mycelial growth promoting ability. Bacterial cell numbers at different steps of the process showed low bacterial cell numbers in spawn and in fruiting bodies inner tissue compared to the high concentration in mycelial-colonized straw. The majority of the 38 isolates belonged to phyla Firmicutes and Actinobacteria were identified as Bacillus, Paenibacillus and Micromonospora species. Similarly, 16S rRNA gene bacterial clones obtained from mycelial biomass DNA samples showed bacterial presence of various genera including Bacillus and Paenibacillus.In the mycelial growth promoting ability tests, 30 isolates negatively affected mycelial growth, two isolates showed no effect on mycelial growth, and six isolates promoted mycelial growth. Moreover, mycelial thickness was influenced in different ways by the bacterial growth. In general, nearly all isolates growth-preventing were isolated from healthy spawn and mycelial-colonized straw, whereas fruiting bodies were the best source for isolation of mycelial growth-promoting bacteria. Characterization of bacterial isolates revealed that growth-preventing isolates exhibited various enzymatic activities in comparison with positive influencing bacteria that exhibited none or weak enzymatic activities. In addition, the influence of volatile compounds being present in the headspace of bi-plate co-cultures on P. ostreatus mycelial growth was demonstrated.The effect of isolates, that promoted mycelial growth in co-cultivation, to reduce P. ostreatus spawn running time, was evaluated on sterilized rye seeds. Results showed that not all mycelial promoted isolates were able to significantly promote P. ostreatus colonization. However, isolate M46F identified as Micromonospora lupini significantly reduce spawn running time. This is one of few studies to estimate cultivable bacteria from healthy samples of P. ostreatus cultivation, to evaluate a bacterial effect on mycelial growth, to show that fruiting bodies are a good source for mycelia growth-promoting isolates, and the first to report a shorter P. ostreatus spawn running time due to bacterial inoculation.

Substrate sterilization with thiophanate-methyl and its biodegradation to carbendazim in oyster mushroom (Pleurotus ostreatus var. florida).

Residue analysis to detect thiophanate-methyl and its primary metabolite (carbendazim) during oyster mushroom (Pleurotus ostreatus var. florida) cultivation was done for two consecutive years 2017 and 2018. Wheat straw substrate was chemically treated with different treatments of thiophate-methyl, viz, thiophanate-methyl 30 ppm + formalin 500 ppm (T1), thiophanate-methyl 40 ppm + formalin 500 ppm (T2), thiophanate-methyl 50 ppm + formalin 500 ppm (T3), thiophanate-methyl 60 ppm + formalin 500 ppm (T4), and formalin 500 ppm (T5 as control and recommended concentration), and utilized for cultivation of oyster mushroom. Treatments T3 and T4 exhibited significant difference in pH levels during both the trials. Minimum spawn run, pinhead formation, and fruit body formation time were recorded in treatments T3 and T4. Significantly higher biological efficiency (%) was recorded in treatments T3 and T4 as compared with all other treatments. No incidence of competitor molds was recorded in T3 and T4. Pesticide residue analysis for detection of thiophanate-methyl and its metabolite (carbendazim) was done in the fruit body produced in T3 and T4 treatments using liquid chromatography with tandem mass spectrometry method. No residue of thiophanate-methyl and carbendazim was detected at 50 ppm concentration of thiophanate-methyl during both the trials. However, in trial II, residue of carbendazim (5.39 μg/kg) was detected at 60 ppm. Based on the findings of the trials I and II, T3 (thiophanate-methyl 50 ppm + formalin 500 ppm) may be utilized for substrate sterilization for oyster mushroom cultivation and Pleurotus ostreatus var. florida could be recognized as microorganism which could play a role in degradation of thiophanate-methyl.

Lignocellulosic and proximate based compositional changes in substrates during cultivation of Hericium erinaceus mushroom

The study was carried out to investigate the potential of several kinds of forestry (oak sawdust (OS), poplar sawdust (PS)) and agricultural byproducts (common vessel straw (CV), wheat straw (WS), safflower wastes (SW) and bean straw (BS)) as growing substrate for Hericium erinaceus cultivation, but also assessing the chemical and lignocellulosic changes occurred in the growing substrates during H. erinaceus cultivation process to understand the needs of the fungus. Moreover, the proximate and lignocellulosic composition of H. erinaceus spent mushroom substrate were presented in the study. Among substrates, CV appeared to promote earliness by presenting shorter cropping periods (29 d), whereas maximum yields (115.8 g/kg and 37.3% BE) and heavier basidiomata (54.1 g) were produced by OS substrates. Spawn running time was correlated positively with carbon to nitrogen ratio (C:N) and lignin content of substrates ( r2 = 0.946), while BEs was positively correlated with lignin content ( r2 = 0.846) and inversely correlated to cellulose/ lignin ratio ( r2=–0.955). The moisture, N, ash, lignocellulosic content of all the substrates were changed greatly during H. erinaceus cultivation, but their rates of change varied at different growing stages. The findings indicate that the shortened spawn run period was correlated with the loss of substrate hemicellulose and high lignin concentration in conjunction to their low cellulose/lignin ratio applies a positive effect on yield and BEs of H.erinaceus.

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.

Compositional changes in lignocellulosic content of some agro-wastes during the production cycle of shiitake mushroom

The study assessed the changes in digestibility of some agricultural wastes such as chickpea straw (CPS), corn stalk (CS), alfalfa hay (AH) and sunflower head residue (SFH) during the spawn running period and fruitbody production of Lentinula edodes (Berk.) Pegler (shiitake) to better understand the nutritional needs of this mushroom species. In addition, the effects of these wastes on some productivity features of shiitake cultivated under laboratory conditions were evaluated. Oak awdust (OS) was used as a control substrate. The substrates were analyzed for nitrogen (N), cellulose, hemicellulose and lignin content at three different growth stages. Morever, the effect of agro-wastes on spawn run time, time to first primordia initiation, time to first harvest, yield, biological efficiency (BE) and average mushroom weight were evaluated during the cultivation cycle. Among the five substrates, the SFH exhibited maximum productivity, followed by CPS (233.7 g/kg and 228.1 g/kg, respectively). No correlation was found between the shiitake yield and the N or lignocellulosic content of the growing substrates. On the other hand, the shiitake consumed hemicellulose during the spawn running period, whereas the consumption of cellulose and lignin occured during the pinheading and fruiting formation stages. The hemicellulose, cellulose and lignin contents in the spent substrate were 36.5–51.9%, 5.3–27.0% and 24.0–36.8% lower, respectively, than in the initial substrates, while the N content in the mushroom substrate was increased by 10.3% (CS)−97.1% (OS) after shiitake cultivation. In conclusion, shiitake mushrooms had a preference for substrates containing a moderate amount of N, hemicellulose and lignin, and having a low cellulose:lignin ratio. Morever, the chemical composition of the growing substrates changed during the life cycle of the mushroom and the protein content increased with time, while the amount of lignocellulosic content in the substrates was reduced, making it more digestible.

Adopting stick spawn reduced the spawn running time and improved mushroom yield and biological efficiency of Pleurotus eryngii

Pleurotus eryngii is a commercially important edible mushroom cultivated widely in Asia, Europe, and North America. We developed a new type of solid spawn (stick spawn) to cultivate P. eryngii. Adopting stick spawn in P. eryngii cultivation reduced spawn running time and improved the yield and biological efficiency (BE). The spawn running time of artificial logs inoculated with stick spawn was only 29.9 days, whereas that of the artificial logs inoculated with sawdust spawn was 53.2 days. The use of stick spawn reduced the spawn running time by 23.3 days (43.8%) compared with the use of sawdust spawn. In addition, adopting stick spawn increased the mushroom yield by 11.5% compared with the use of sawdust spawn. In conclusion, the use of stick spawn resulted in shorter spawn running time and higher mushroom yield and BE.

CULTIVATION POSSIBILITY OF GOLDEN OYSTER MUSHROOM (PLEUROTUS CITRINOPILEATUS) UNDER THE EGYPTIAN CONDITIONS

Among higher fungi, Pleurotus is well acknowledged as an economically important genus. This may be attributed to its world-wide distribution, its broad adaptability to various conditions. Pleurotus citrinopileatus has a very attractive yellow color, good culinary properties, and has highly appreciated commercial potentials in many countries. This Pleurotus type was newly introduced to Egypt from China. This investigation was carried out to determine the cultivation possibility of this new mushroom type under the domestic conditions using the cheap available agro-wastes throughout three consecutive seasons. Rice straw, wheat straw and sawdust were used as base substrates for growing media formula. Growing parameters such as spawn run (incubation time), pinheads initiation, fruit bodies development (maturation) time, yield and biological efficiency (BE%) were studied. Main chemical constituents of the P.citrinopileatus were estimated. The yielded fruit bodies were dried either by sun or oven and drying data was recorded. Spawn run time ranged from (18-28), (18- 30), (16- 26) days for first, second and third season, respectively .Fruit bodies development (maturation) were 6-8 days for all tested media. The total fresh yield ranged from 137- 393 g/ kg wet media with BE% of 38-115% for all media through the tested three seasons. The mixture of rice straw and wheat straw media gave the highest yield, while the sawdust media produced the lowest one. P.citrinopileatus fruit bodies contained 85.90- 87.37% moisture content, 22.84 – 26.01% crude protein, 2.59 – 3.23% crude fat, 7.76 – 9.06% ash and 63.77 – 65.58% total carbohydrates on dry weight basis. The fruit bodies required 35- 55 hrs. for sun drying, while they took 9 – 14 hrs for oven dehydration. Control and sulfured samples dried either by sun or oven showed superior values for rehydration ratio and sensory characteristics. According to the obtained data it could be recommended that P. citrinopileatus cultivation could be spread and encourged using the available materials in Egypt.

Effect of different grain spawns and substrate sterilization methods on yield of oyster mushroom in Botswana.

The effect of three different grain spawns and two substrate sterilization methods on the spawn quality and yield of a hybrid of Pleurotus ostreatus x P. florida (Po x Pf) was studied on maize cobs supplemented with 20% wheat bran and 2% gram flour in a low technological mushroom house at Botswana College of Agriculture, Sebele. Sorghum grains proved to be better mycelium carriers (5.25, 7 days, 12 days and 75.4%) over wheat (2.45, 17 days, 16 days and 53.55%) and barley grains (3.46, 14 days, 13 days and 55.24%) in terms of mycelium growth vigor, colonization time, spawn running time of the substrate and yield of the oyster mushroom. Hot water treatment and steaming of substrate significantly reduced substrate contamination and improved mushroom yield as compared to the untreated control. Mushrooms grown on steamed substrates had significantly higher yield (BE: 69.4%) than those grown on substrates treated with hot water (BE: 53.3%).

Cultivation of oyster mushroom (Pleurotus spp.) on palm oil mesocarp fibre

Oyster mushroom is a popular mushroom due to its nutritional, medicinal and potential commercial value. In Malaysia, the fungus is currently cultivated on sawdust and rice husk. In this study, the efficiency of cultivating oyster mushroom was assessed using palm oil mesocarp fibre as a substrate. The experiment consisted of four samples; sample A (composed of 100% mesocarp fibre), sample B (composed of 88% fiber,10% rice bran and 2% lime), sample C (composed of 85% fiber,10% rice bran and 5% lime), and sample D (composed of 50% fibre, 10% rice bran, 38% sawdust and 2% lime). Different spawn running time was determined and fruiting bodies were also observed. Results indicate that samples B, C, and D fruiting bodies were higher and better than that in sample A, thus establishing that palm oil fibre served as a good substrate for the cultivation of Pleurotus spp. A further study on the protein composition of oyster mushroom (Pleurotus spp.) is however suggested.

Effect of environmental factors on the yield of selected mushroom species growing in two different agro ecological zones of Pakistan

Mushrooms are a rich source of protein and vitamins as human food. In view of the growing importance of mushroom in Pakistan, a research study was initiated with the objective to examine the suitability of Oyster mushroom cultivation and to compare the growth and yield of Oyster mushroom in two different areas (Peshawar and Swat, North-West region of Pakistan) with different ecological conditions. Spawn running time, number of crops, stalk height, stalk diameter, cap size, fresh weight, number of production days, and the interval in days between the time of bag opening and the time of starting fruiting bodies formation were among the important parameters investigated in the current study. Stalk height, stalk diameter, cap size and fresh weight of mushrooms were found higher in Peshawar region as compared to those growing in Swat region. On the other side, the spawn running time, formation of fruiting bodies and the number of productions were higher in Swat region as compared to the mushroom under study in Peshawar region. Mild winter temperatures of Peshawar region, and low summer temperatures in Swat, were found most suitable for growth and yield of Pleurotus ostreatus.

Hazelnut husk as a substrate for the cultivation of shiitake mushroom ( Lentinula edodes)

The possibility of using hazelnut husk (HH) as a new basal ingredient for substrate preparation in Lentinula edodes cultivation was investigated. Some chemical properties of the substrates prepared by HH alone and its mixtures with wheat straw (WS), beech wood-chip (BWC) and wheat bran (WB) in different ratios were compared, and their effects on spawn run time, days to first harvest (earliness), yield and biological efficiency (BE) were determined. The N content of the substrate prepared from HH alone was very high (0.82%), and thus the C:N ratio of substrates decreased with an increase in the rate of HH in the mixtures. Yield and BE in the HH alone substrate was considerably low compared with the controls (80BWC:10WS:10M and 60BWC:20WS:20WB), and decreased with an increase in the rate of HH in the mixtures. However, when the HH content in the mixtures was kept below 50%, the yield was relatively high (50HH:50WS and 50HH:50BWC). Even when the HH content increased to 75% in the mixture, the comparable yield and BE to the controls could be obtained by adding 10% of WB as nutrients (75HH:15WS:10WB and 75HH:15BWC:10WB). The results revealed that HH could be used as a new basal ingredient for substrate preparation in L. edodes cultivation.

Note. Production of shiitake mushroom (Lentinus edodes) on lignocellulosic residues / Nota. Cultivo del hongo shiitake (Lentinus edodes) en residuos lignocelulósicos

Fungi, namely white-rot fungi, growing on lignocellulosic substrates such as wood and straw secrete a mixture of hydrolytic and oxidative enzymes that depolymerize the substrate components. Biocon version of lignocellulosic agro-residues through mushroom cultivation offers the potential for con verting these residues into protein-rich palatable food, reducing the environmental impact of the wastes. The growth of four strains of the mushroom Lentinus edodes (Berk.) Sing. in four different substrates was studied. The mushrooms were cultivated in particulate sawdust substrates enclosed in autoclavable plastic bags. This 'space bag' production of biomass offers foreshortened production cycles. The fructification phase occurred during 10 days after a spawn-run time of 90 days compared with 18 months to two years for traditional methods. Mushroom production depended on strain, varying from 12.5% to 15.0%. Biological efficiency comprised between 42.3% and 59.5%. The fruiting bodies were analyzed to determine their nutritional value. They had high contents of protein and total carbohydrates but low contents of lipids and nucleic acids. L. edodes has low fiber content com pared with other species. Cellulose degradation was similar for all the strains which had produced carpophores. Lignin degradation comprised between 40.7% and 59.10%.

Effect of water potential on fruit body formation ofLentinula edodes in sawdust-based substrate

The influence of substrate water potential (ψ) on the growth and fruiting of three genotypes of shiitake (Lentinula edodes) was investigated. A slight reduction ofψ (−0.5MPa) stimulated mycelial and colony growth on liquid, agar, and sawdust-based substrates.L. edodes has been found to grow well at aψ around −0.5 MPa, which corresponds to a moisture content around 55%. A small decrease inψ at the final vegetative growth phase had positive effects on flush quantity. The substrateψ was significantly affected by the interaction between genotypes and spawn run time. Theψ of well-colonized mature substrate was −0.7MPa before and −4.OMPa after the fruiting. Theψ rose again to −0.7MPa during rapid absorbance of water by soaking, and this rise was repeated during the second and third flushes. It is suggested that the water-holding capacity of a substrate is related to culture maturity. Excellent water-providing capacity (higherψ) is expected in the substrate of well-matured cultures with a high density of mycelial colonization.