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Agricultural activities produce large quantities of organic byproducts and waste rich in lignocellulosic materials, which are not sufficiently utilized. In this study, alternative agricultural waste products, namely, spent mushroom substrate (SMS) from the cultivation of edible Pleurotus ostreatus mushrooms and the roots of leafy vegetables from hydroponic cultivation (HRL), were evaluated for their potential to be used as substrates for the cultivation of Pleurotus citrinopileatus and their effects on the quality, the nutritional value, the chemical properties (lipid, protein, carbohydrate, ash, fatty acid and carbohydrate composition) and the bioactive content (total phenolic compounds and antioxidant activity) of produced mushrooms. SMS and HRL (in different ratios with and without additives) and wheat straw with additives (WS—control) were used. During incubation, the linear growth rate of the mycelium (Kr, mm/day) was measured and used for screening. Mushroom cultivation took place in bags, where several characteristics were examined: earliness (duration between the day of substrate inoculation and the day of first harvest) and biological efficiency (B.E. %, the ratio of the weight of fresh mushrooms produced per dry weight of the substrate × 100). Furthermore, this study aimed to investigate the effect of the protein extract (PE) and carbohydrate extract (CE) of P. citrinopileatus after in vitro digestion (fraction less than 3kDa: PE-DP-3; digestate fraction: CE-D, respectively) on the expression of antioxidant-related genes in the THP-1 cell line. The results showed that mushrooms grown on SMS 50%-HRL 40% had the fastest growth (6.1 mm/d) and the highest protein and lipid contents (34.7% d.w.; 5.1% d.w.). The highest B.E. (73.5%), total carbohydrate (65.7%) and total phenolic compound (60.2 mg GAE/g d.w.) values were recorded on the control substrate. Antioxidant activity was observed in all extracts; the total flavonoid content was low in the samples, and the maximum total triterpene value was detected in SMS 80%-HRL 20% (9.8 mg UA/g d.w.). In all mushrooms, linoleic acid (C18:2) was the main fatty acid (above 60%), and fructose was the dominant individual saccharide. In the investigation of the regulation pathway, NFE2L2 gene expression was upregulated only in the SMS 60%-HRL 40% intervention during incubation with CE-D samples. Additionally, the transcription levels of antioxidant-related genes, SOD1, CAT, HMOX1 and GSR, were increased in the SMS 60–30% intervention. Compared to WS, the alternative substrates are observed to trigger a pathway concerning CE that may resist oxidative stress. This study supports the utilization of agricultural byproducts through sustainable and environmentally friendly practices while simultaneously producing high-value-added products such as mushrooms. Therefore, alternative substrates, particularly those containing HRL, could serve as natural sources of antioxidant potential. [ABSTRACT FROM AUTHOR]

In the present review-article several aspects dealing with the biotechnological production of three major sugar-alcohols, viz. erythritol, mannitol and arabitol, are developed. Emphasis is given on the extra-cellular production of these sugar-alcohols by species of the yeast cell factory Yarrowia lipolytica and/or their intra-cellular accumulation in genera/species (mostly Agaricus and Pleurotus) of edible and medicinal mushrooms. Indications concerning the presence of soluble sugars inside the fungal mycelia and fruit-bodies of various types of mushrooms are also added. Initially, general information concerning the mentioned sugar-alcohols as well as others that are produced by biotechnological means, their roles, and their functionalities, are presented. The biochemistry of the synthesis of erythritol, mannitol and arabitol in the yeast cells and fungal mycelia when the main carbon sources employed in the Industrial Biotechnology (viz. glucose/fructose, lignocellulosic compounds/xylose, hydrophobic materials, glycerol) are used is presented and critically discussed. Given that the yeast Y. lipolytica is a major candidate that has been/is implicated in the production of the mentioned sugar-alcohols together with other compounds that are synthesized through similar metabolic pathways (viz. microbial lipids and citric acid, produced as the mentioned polyols during the imbalanced growth phase and after carbon-excess and nitrogen-limited conditions) various considerations concerning the biotechnological potential of this yeast species with emphasis of the production of sugar-alcohols are developed and assessed. Finally, presentations concerning the production of sugar-alcohols and other soluble sugars through the cultivation of various types of edible/medicinal mushrooms in several types of fermentation configurations are critically assessed. [Display omitted] • State-of-the-art presentations of sugar-alcohols production by Yarrowia lipolytica. • State-of-the-art presentations of sugar-alcohols production by edible and medicinal mushrooms. [ABSTRACT FROM AUTHOR]

Vast quantities of side streams produced worldwide by the agricultural and food industry present an environmental challenge and an opportunity for waste upcycling in the frame of the circular bioeconomy. Fungi are capable of transforming lignocellulosic residues and wastes into a variety of added-value compounds with applications in functional food products, pharmaceuticals, chemicals, enzymes, proteins, and the emerging sector of nutraceuticals. The liquid state culture of fungi is an efficient and potentially scalable and reproducible biotechnological tool that allows the optimized production of fungal metabolites. Particularly, the utilization of agro-industrial by-products, residues, and wastes as a substrate for the liquid culture of macrofungi is suggested as an attainable solution in the management of these streams, contributing to climate change mitigation. This review presents recently published literature in the field of liquid state cultures of macrofungi using agro-industrial side streams, the different substrates, methods, and factors affecting their growth and metabolite production, as well as their applications, focusing on the variety of natural valuable compounds produced. [ABSTRACT FROM AUTHOR]

Five Agaricus bisporus commercial strains (S100, A15, F56, F40 and F62) were evaluated as regards their colonization rates, yields, quality characters and storability. Concerning their colonization performance, the mycelial growth rates examined in “race tubes” on sterile compost, as well as earliness in fructification did not differ significantly. Significantly lower was the yield of strain S100 compared to the yield of strains F62 and F56, which presented the greatest cumulative biological efficiency values. However, mushroom number and average weight presented negative relation. For the storage and quality study, mushrooms at the “closed-cap” stage packaged in 500-g plastic containers were stored for 5 days at 2C and 5 days at 18C (shelf life). The respiration behavior of the five strains was similar with the mass loss not exceeding 15% during storage at 2C and 40–50% at the end of the shelf life. Also, no differences in the whiteness and texture change were detected and a correlation between the period of pileus diameter increase and the respiration rate was found. According to their color and texture quality assessment, mushrooms deriving from the first four strains may be considered well acceptable at the end of the shelf life, whereas these from strain F62 just saleable. [ABSTRACT FROM AUTHOR]

Lentinula edodes mushrooms were produced by solid-state fermentation, using as substrates different mixtures of wheat straw (WS), corn-cobs (CC), and oak-wood sawdust (OS). Studies were conducted for evaluating their bio-transformation efficiency with respect to substrate colonization, time of sporophore production, biological efficiency, and mushroom nitrogen content, as well as basidiocarp number and size. First, the potential of residue-substrates to support early fructification was evaluated in glass-tubes. The mushrooms appeared 50–60 days after inoculation, with WS and CC promoting earlier sporophore initiation than did OS. A second experiment, where L. Edodes mushrooms were cultivated in ‘bag-logs’, revealed high productivity on CC and high mushroom protein content on OS-based substrates. However, WS appeared to promote early fructification and mushroom quality. Finally, mushroom production characteristics in tubes and bags were correlated with nitrogen content and C/N ratio of substrates. Early fructification was positively related to nitrogen content. Substrate mixtures with lower C/N ratio favoured earlier sporophore induction. [Copyright &y& Elsevier]

Dissipation of the fungicides famoxadone and trifloxystrobin in basidiocarps of Agaricus bisporus was studied in mushroom growing rooms. The mushroom samples taken at all three consecutive production flushes following single or split applications of the fungicides were extracted with solvents and the residues were determined by using a gas chromatograph equipped with an electron capture detector (GC-ECD). Recoveries from the fortified control samples ranged from 87 to 105%. Following drench applications at 0.1–1 g/m 2 of culture bed area, the highest famoxadone residue determined in basidiocarps was 0.1447 mg/kg. Analysis of trifloxystrobin revealed a quantitative relationship between the application rate (0.8–1.8 g/m 2 ) and the residue levels of both the parent compound and its acid metabolite. The maximal combined residues of trifloxystrobin and its metabolite were 0.1313 mg/kg. Short- and long-term dietary risk assessment for both fungicides was carried out using consumption data from World Health Organization and the UK Pesticide Safety Directorate's Ten Consumer Model. The potential acute and chronic residue intakes via mushroom consumption were below toxicologically significant indicators. [ABSTRACT FROM AUTHOR]

Spent mushroom substrate (SMS) of Pleurotus ostreatus was supplemented with wheat bran and soybean flour and used as substrate for a new cultivation cycle of the oyster mushrooms Pleurotus ostreatus and Pleurotus pulmonarius. The bioconversion efficiency of mushrooms produced over substrate (BE%) used and the chemical composition of sporophores were evaluated. The concentration of mycelial mass, crude exopolysaccharide content and laccase enzyme activity were also determined at the supplemented SMS before inoculation, at 50% and 100% of colonization stages in the new cultivation and in the final re-utilized SMS. The laccase enzyme was extracted to examine SMS potential for the dephenolization of olive mill and winery wastewaters. Results showed that both Pleurotus species exhibited BE over 185%, demonstrating this bioprocess could represent a promising strategy to convert SMS into nutritional food. Data also indicate the strong positive impact that SMS could have in the solid wastes' management and agribusiness enhancement. [ABSTRACT FROM AUTHOR]