Optimization of agro-residues as substrates for Pleurotus pulmonarius production

Comparative analyses of Pleurotus pulmonarius mitochondrial genomes reveal two major lineages of mini oyster mushroom cultivars

Pleurotus pulmonarius, commonly known as the mini oyster mushroom, is highly esteemed for its crisp texture and umami flavor. Limited genetic diversity among P. pulmonarius cultivars raises concerns regarding its sustainable industrial production. To delve into the maternal genetic diversity of the principal P. pulmonarius cultivars, 36 cultivars and five wild isolates were subjected to de novo sequencing and assembly to generate high-quality mitogenome sequences. The P. pulmonarius mitogenomes had lengths ranging from 69,096 to 72,905 base pairs. The mitogenome sizes of P. pulmonarius and those of other mushroom species in the Pleurotus genus showed a significant positive correlation with the counts of LAGLIDAG and GIY-YIG homing endonucleases encoded by intronic open reading frames. A comparison of gene arrangements revealed an inversion of a fragment containing atp9-nad3-nad2 between P. pulmonarius and P. ostreatus. The mitogenomes of P. pulmonarius were clustered into three distinct clades, two of which were crowded with commercial cultivars. Clade I, all of which possess an inserted dpo gene, shared a maternal origin linked to an ancestral cultivar from Taiwan. Primers were designed to target the dpo gene, potentially safeguarding intellectual property rights. The wild isolates in Clade III exhibited more divergent mitogenomes, rendering them valuable for breeding.

Understanding the drying mechanism of straw substrate culture block: Physicochemical properties, pore structure, and drying optimization

As a new type of agricultural waste block substrate utilization, the initial wet base state of the substrate culture block needs to be dried. Therefore, studying the drying mechanism of substrate culture block is critical. In this study, the substrate culture block in a dry state was taken as the research object. Based on physical and chemical properties, the internal section of the substrate culture block was characterized by scanning electron microscopy and the pore condition of the particles was quantified. The results showed that the internal pore structure was uniform and favorable for plant root growth. Based on the pore structure, pore channel modeling was constructed to investigate the distribution of the internal multiphase medium and to distinguish between channels and pore-blind channels. The applicability of the modeling was verified and discussed. By measuring the drying rate of the substrate culture block and classifying its drying stages as fast speed, constant speed, and slow speed, it is clarified that the forms of moisture existence are bound-state water and free-state water, and the moisture migration is prioritized as surface adsorption water, interparticle water, particle attached water, and capillary water. Innovate a method to quantify the change of pore space in the drying process by pore coefficient ratio to evaluate the drying quality. The results show that when the pore coefficient ratio is about 40 %, its moisture content is 20 %∼30 %, and the drying effect is best at this time. The physical drying test further confirmed the correctness of the conclusion of the drying stage division and water loss law. This study can provide a theoretical reference for the modeling study of the pore structure of the block matrix and the exploration of its drying mechanism.

Application of Miscanthus substrates in the cultivation of Ganoderma lingzhi

Ganoderma lingzhi is a traditional Chinese medicine that has been used to improve health and longevity for thousands of years. It is usually cultivated on hardwood log- or sawdust-based formulations. Conversely, in this study, we used Miscanthus sacchariflorus (MSF), M. floridulus, and M. sinensis (MSS), fast-growing perennial grasses widely distributed in China, for G. lingzhi cultivation. Mycelial growth rate, activities of lignin-degrading enzymes on colonized mushroom substrates, and expression levels of CAZymes and laccase genes based on different substrates were analyzed. Total triterpenoids, sterols, and polysaccharides content of fruiting bodies obtained from different substrates were investigated. The activities of laccase and manganese peroxidase in mycelia increased in the MSF- and MSS-based formulations compared with that in the sawdust-based formulation. The results of mycelial growth- and cultivation-related experiments showed that the Miscanthus substrates could be used as the substrates for cultivating G. lingzhi. The content of active ingredients, namely triterpenoids, sterols, and polysaccharides, in fruiting bodies cultivated on the Miscanthus substrates did not decrease compared with those in substrate obtained from the sawdust-based formulation. Therefore, the present study provides alternative substrates for the cultivation of G. lingzhi, and a reference for better utilization of inexpensive substrate in future.

Antimicrobial, Antioxidant, Cytotoxicity and DNA Protective Properties of the Pink Oyster Mushroom, Pleurotus djamor (Agaricomycetes)

In this study, pink oyster mushroom Pleurotus djamor was cultivated using wheat straw (WS), quinoa stalk (QS), and their mixtures (WS-QS (1:1)) as substrate and evaluated in terms of antimicrobial, antioxidant, cytotoxicity, and DNA protective effects. Gram-positive and Gram-negative pathogen bacteria (Bacillus subtilis, Proteus vulgaris, Streptococcus mutans, Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli), dermatophyte (Trichophyton sp.) and yeast (Candida tropicalis) were used in the study. It was found to be very active against all bacteria (except S. mutans and S. typhi), and dermatophyte when compared to the control groups (8.7-33.3 mm), but low against C. tropicalis. It was seen that the best total antioxidant assay (TAS) value was 2.05 mmol/L on WS-QS (1:1). Depend on, it was determined that the total oxidant assay (TOS) value (5.26 μmol/L) in the same compost was lower than the others, and also the scavenging effect of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) was higher on WS at 25 mg/mL (84.20%). The methanol extract on WS at a concentration of 400 μg/mL, significantly reduced the percentage of viability in the human breast cancer (MDA-MB-231) cell line (2.2%). The methanol extracts on WS and QS medium were found to inhibit DNA damage induced by UV radiation and H2O2 at a concentration of 25 mg/mL. These results showed that pink oyster mushroom has benefits such as antimicrobial, antioxidant, cytotoxic, and DNA protective effects.

The yield, nutritional value, umami components and mineral contents of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes

This study was carried out to evaluate the yields and quality of the first-flush and second-flush Pleurotus pulmonarius mushrooms grown on three forestry wastes (pine, poplar, and honeysuckle rattan). The biological efficiency (BE) of the substrates varied from 61.89% to 81.01%. The total protein content, gamma-aminobutyric acid (GABA) content and equivalent umami concentration (EUC) values of the mushrooms were greatly influenced by the flush number and the substrate, however, the total sugar content and ergosterol content of the mushrooms were not significantly affected. The first-flush mushrooms that were grown on the pine sawdust-based substrate had the highest protein content, and the first-flush mushrooms that were grown on the honeysuckle rattan sawdust-based substrate had the highest GABA content and EUC values. All the mushroom samples accumulated Cu but excluded Ca, Mn, Pb, Cr, and Cd, and the concentrations of Mg, Fe, and Mn are species and flush number dependent.

Edible mushroom industry in China: current state and perspectives

China is one of the largest producers and exporters of wild edible fungi in the world. Cultivation mushroom production value ranks within the top five after grain, vegetable, fruit, and edible oil plantation, greater than sugar, cotton, and tobacco business. More than 40 new varieties of high market value mushrooms from our group were highlighted in this article. Mushroom cultivations have a high impact on China's poverty alleviation program, with earnings at least ten times higher than rice and corn. The products were exported to 137 countries and regions, mainly to Japan, South Korea, ASEAN, the USA, and the European Union, among these, Japan is the biggest import market for cultivated mushrooms from China. Rapid development in the market and an increased demand for edible fungi generally enhance the economy of domestic edible fungi. We are the leading research group in logical farm design that is HACCP-certified to reduce the cost of investment for agriculture, thus broadening the consumption market of edible mushrooms and forming a demand-oriented leading industry for the promotion of human health. The enterprise needs to re-examine the operation plan and the strategic thinking to improve the fundamental drivers based on the available resources of the locality. Mushrooms growing intergrate with upgraded technologies and equipment to become smart agriculture which have smart production and intelligent factories. The purpose of suitable products will not change: delicious, nutritious, healthy, and modern. KEY POINTS: • Cultivation mushroom production value ranks within the top five after grain, vegetable, fruit, and edible oil plantation, greater than sugar, cotton, and tobacco business. • Mushroom cultivations have a high impact on China's poverty alleviation program, with earnings at least ten times higher than rice and corn. • The development of transportation and industrialization of mushrooms facilitate the modernization of mushroom industry in China.

Mushroom Quality Related with Various Substrates' Bioaccumulation and Translocation of Heavy Metals

Mushrooms are popular due to the nutrition contents in the fruit bodies and are relatively easy to cultivate. Mushrooms from the white-rot fungi group can be cultivated on agricultural biomass such as sawdust, paddy straw, wheat straw, oil palm frond, oil palm empty fruit bunches, oil palm bark, corn silage, corn cobs, banana leaves, coconut husk, pineapple peel, pineapple leaves, cotton stalk, sugarcane bagasse and various other agricultural biomass. Mushrooms are exceptional decomposers that play important roles in the food web to balance the ecosystems. They can uptake various minerals, including essential and non-essential minerals provided by the substrates. However, the agricultural biomass used for mushroom cultivation is sometimes polluted by heavy metals because of the increased anthropogenic activities occurring in line with urbanisation. Due to their role in mycoremediation, the mushrooms also absorb pollutants from the substrates into their fruit bodies. This article reviews the sources of agricultural biomass for mushroom cultivation that could track how the environmental heavy metals are accumulated and translocated into mushroom fruit bodies. This review also discusses the possible health risks from prolonged uptakes of heavy metal-contaminated mushrooms to highlight the importance of early contaminants’ detection for food security.

The yield and quality of Pleurotus abieticola grown on nematode-infected Pinus massoniana chips

In this study, we investigated the use of nematode-infected Pinus massoniana chips (NPC) as the main ingredient in Pleurotus abieticola substrate. The effects of different substrate formulas on nutritional parameters, including total sugars, polysaccharides, proteins, lipids, amino acids, and fatty acids were assessed. The results indicated that NPC was suitable for P. abieticola cultivation. However, the addition of certain amounts of corncobs (CC) and cottonseed hulks (CH) improved the yield. Substrate T5 (45% NPC, 6% CC, and 27% CH) had the greatest yield (121.38 g per bag), 34.56% greater than the yield of the control (78% poplar chips), which was 79.43 g per bag. Across the 11 substrate formulas tested, the total sugar, polysaccharide, crude protein, and crude lipid contents were 16.60-28.90%, 2.71-3.73%, 36.49-45.42%, and 1.03-4.34%, respectively. On all substrates, the fruiting bodies contained 17 amino acids, primarily glutamine (2.42-4.11%), followed by proline (2.56-3.73%), leucine (2.09-3.19%), phenylalanine (1.56-2.61%), and glycine (1.76-2.55%). The fruiting bodies contained 12 fatty acids, of which linoleic acid was the most abundant (82.36%-84.03%), followed by palmitic acid (6.42%-6.89%) and oleic acid (5.50%-7.34%). The fatty acid content was closely associated with the NPC content, which might indicate that NPC promoted fatty acid accumulation. Thus, NPC represents a new substrate suitable for P. abieticola cultivation.

Bioactivity assessment of exopolysaccharides produced by Pleurotus pulmonarius in submerged culture with different agro-waste residues

Pleurotus spp. are white-rot fungi that utilize different agro-wastes to produce useful biologically active compounds. In this study, exopolysaccharides (EPS) were produced by Pleurotus pulmonarius in submerged culture supplemented with different agro-wastes. Functional groups in EPS were revealed using Fourier Transform-Infrared (FT-IR) spectroscopy. Antimicrobial activity of EPS was tested against microorganisms using agar well diffusion. Scavenging potentials of EPS was tested against 1, 1- diphenyl-2-picryhydrazyl (DPPH), hydroxyl (OH), iron (Fe2+) and nitric oxide (NO) radicals. In vitro prebiotic activity of EPS was carried out. The highest yield (5.60 g/L) of EPS was produced by P. pulmonarius in submerged culture supplemented with groundnut shell (20.0 g/L). The functional groups in EPS were hydroxyl (-OH), methyl (-CH3), ketone (-RCOH) and carbonyl group (-C=O). EPS displayed zones of inhibition (5.00-14.00 mm) against tested microorganisms. Scavenging activity of EPS ranged from 65.70-81.80% against DPPH. EPS supported the growth of Lactobacillus delbrueckii and Streptococcus thermophiles with values ranged from 3.04 × 104-3.40 × 104 cfu/ml and 2.50 × 104-2.81 × 104 cfu/ml, respectively. Submerged culture of P. pulmonarius with addition of agro-wastes enhanced yield of EPS. The EPS exhibited bio-functional properties like antimicrobial, antioxidant and prebiotic activities. Hence, agrowastes can be recycled in submerged fermentation with fungi to produce promising biomaterials for biopharmaceutical applications.