Data-Mining Techniques: A New Approach to Identifying the Links among Hybrid Strains of Pleurotus with Culture Media

In this study, a data set of mycelial and cultural characteristics of hybrid strains of Pleurotus ostreatus and Pleurotus djamor were analyzed using three data-mining techniques: the K-medoids clustering algorithm, PCA biplot and the association rules algorithm. The characteristics evaluated were as follows: maximum velocity; lag phase; biomass; and exopolysaccharides content in the cultivation of 50 hybrid strains of Pleurotus ostreatus and 50 hybrid strains of Pleurotus djamor. Different mixtures of culture media were used to supplement Ecuadorian agricultural products. Data of the parameters obtained in the experimental methods were grouped into four clusters, obtaining a presentation of the hybrid strains of Pleurotus with a higher relation to each characteristic measured. Data-mining tools showed the hybrid strains cultivated on solid-culture media (M1 = malt extract agar and rice flour) and liquid-culture media (L1 = maltose, yeast extract and rice flour) presented the highest mycelial and cultural characteristics. These results are good indicators to improve the industrial production of edible fungi by using rice flour in the cultivation, contributing to the mushroom market and circular economy.

Efecto del pH y Sales Inorgánicas en la Degradación de Colorantes Industriales por Pleurotus Djamor

En la presente investigación se planteó el uso de la cepa Pd318 del hongo Pleurotus djamor como agente biorremediador, con el objetivo de evaluar su capacidad para degradar el colorante reactivo azul 19 (A19). Para ello se estudió la influencia que tienen cinco sales inorgánicas en el crecimiento y actividad lignolítica del hongo. Un cribado de sales inorgánicas en placa determinó que las sales CaCl2.2H2O y MnSO4.5H2O tienen mayor influencia en el desarrollo micelial y actividad lignolítica de la cepa. Ensayos de fermentación líquida (FEL) con diferentes combinaciones a distintas concentraciones de las sales de calcio y manganeso permitieron demostrar la capacidad de degradación del colorante azul 19 a los 7 días de fermentación líquida a temperatura ambiente y agitación constante. Los máximos porcentajes de degradación del colorante fueron obtenidos con las combinaciones A1B1 y A2B1 con 43,47% y 41,36%, respectivamente. Se observó que a un pH de 5 unidades se favorece la degradación del colorante. Los estudios en placa señalaron que la adición de sales de calcio y manganeso en 10 días de incubación favorecieron el desarrollo micelial y la actividad lignolítica de Pd318, mientras que en un sistema FEL de 7 días, únicamente la adición de manganeso influye favorablemente a la actividad lignolítica del hongo y en consecuencia a su capacidad de degradación de azul 19. Palabra clave: Colorante azul 19, degradación de colorantes, enzimas lignolíticas, Pleurotus djamor. Abstract In the present investigation, the use of the Pd318 strain of the Pleurotus djamor fungus as a bioremediation agent was proposed, with the aim of evaluating its ability to degrade reactive dye blue 19 (A19). For this, the influence of five inorganic salts on the growth and lignolytic activity of the fungus was studied. A plate screening of inorganic salts determined that the CaCl2.2H2O and MnSO4.5H2O salts have a greater influence on the mycelial development and lignolytic activity of the strain. Liquid fermentation tests (FEL) with different combinations at different concentrations of the calcium and manganese salts allowed to demonstrate the degradation capacity of the blue dye 19, after 7 days of liquid fermentation at room temperature and constant stirring, the maximum degradation percentages of the dye were obtained with the combinations A1B1 and A2B1 with 43.47% and 41.36% respectively. It was observed that at a pH of 5 units the degradation of the dye is favored. The plate studies indicated that the addition of calcium and manganese salts in 10 days of incubation, favored mycelial development and the lignolytic activity of Pd318, while in a 7 day FEL system, only the addition of manganese favorably influenced the lignolytic activity of the fungus and consequently its ability to break down blue 19. Keywords: Blue dye 19, dye degradation, lignolytic enzymes, Pleurotus djamor.

Utilização do bagaço de malte da indústria cervejeira como substrato para produção de pectinase por cogumelos / Utilization of beer spent grain from the brewing industry as substrate for mushroom pectinase production

O aumento da produção de cerveja promoveu, consequente, aumento na geração de resíduos, como o bagaço de malte, provenientes dessa atividade industrial, intensificando a necessidade de seu reaproveitamento. Uma alternativa para isso, é a utilização dos resíduos da indústria cervejeira como fonte de carbono no cultivo de macrofungos (cogumelos), visando a produção de biomoléculas, como enzimas, de importante interesse pelas indústrias. O objetivo desse estudo foi avaliar a produção de pectinase por duas espécies de basiomicetos, Pleurotus djamor e Hypsizygus ulmarius, a partir de cultivo submerso, tendo o bagaço de malte como fonte de carbono e aplicando um delineamento composto central rotacional para otimização das variáveis do processo: concentração de substrato, temperatura e agitação. Para a produção de pectinase por P. djamor, as variáveis que melhor influenciaram o processo foram concentração de bagaço de malte (30 g/L), temperatura (29°C) e agitação (75 rpm), quando obteve-se atividade enzimática de 2,544 U/mL. Já o cultivo de H. ulmarius para produção de pectinase, as variáveis que melhor influenciaram o processo foram concentração do bagaço de malte (30 g/L), temperatura (24°C) e agitação (150 rpm), quando foi verificada atividade enzimática de 2,367 U/mL. Ensaios de estabilidade térmica de pectinase obtidas a partir do cultivo submerso em bagaço de mate, de ambas espécies de basiodiomicetos, indicaram bom desempenho da enzima sob temperaturas mais altas (80°C). Estes resultados, sugerem portanto que o bagaço de mate é uma fonte de carbono interessante a ser aplicada no cultivo submerso de P. djamor e H. ulmarius visando a produção de pectinase .

Revalorization of Pleurotus djamor Fungus Culture: Fungus-Derived Carbons for Supercapacitor Application

Currently, there is increasing interest and effort directed to developing sustainable processes, including in waste management and energy production and storage, among others. In this research, corn cobs were used as a substrate for the cultivation of Pleurotus djamor, a suitable feedstock for the management of these agricultural residues. Revalorization of this fungus, as an environmentally friendly carbon precursor, was executed by taking advantage of the intrinsic characteristics of the fungus, such as its porosity. Obtaining fungus-derived porous carbons was achieved by hydrothermal activation with KOH and subsequent pyrolysis at 600, 800, and 1000 °C in an argon atmosphere. The morphologies of the fungal biomass and fungus-derived carbons both exhibited, on their surfaces, certain amorphous similarities in their pores, indicating that the porous base matrix of the fungus was maintained despite carbonization. From all fungus-derived carbons, PD1000 exhibited the largest superficial area, with 612 m2g−1 and a pore size between 3 and 4 nm recorded. Electrochemical performance was evaluated in a three-electrode cell, and capacitance was calculated by cyclic voltammetry; a capacitance of 60 F g−1 for PD1000 was recorded. Other results suggested that PD1000 had a fast ion-diffusion transfer rate and high electronic conductivity. Ultimately, Pleurotus djamor biomass is a suitable feedstock for obtaining carbon in a sustainable way, and it features a defined intrinsic structure for potential energy storage applications, such as electrodes in supercapacitors.

Application of Fungus Enzymes in Spent Mushroom Composts from Edible Mushroom Cultivation for Phthalate Removal

Spent mushroom composts (SMCs) are waste products of mushroom cultivation. The handling of large amounts of SMCs has become an important environmental issue. Phthalates are plasticizers which are widely distributed in the environment and urban wastewater, and cannot be effectively removed by conventional wastewater treatment methods. In this study, SMCs are tested for their ability to remove phthalates, including benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), and diethyl phthalate (DEP). Batch experiments reveal that BBP, DBP, and DEP can be degraded by the SMC enzyme extracts of four edible mushrooms: Pleurotus eryngii, Pleurotus djamor, Pleurotus ostreatus, and Auricularia polytricha. Potential fungus enzymes associated with BBP, DBP, and DEP degradation in SMCs (i.e., esterases, oxygenases, and oxidases/dehydrogenases) are uncovered by metaproteomic analysis using mass spectrometry. Bioreactor experiments indicate that the direct application of SMCs can remove BBP, DBP, and DEP from wastewater, through adsorption and biodegradation. The results of this study extend the application of white-rot fungi without laccases (e.g., Auricularia sp.) for the removal of organic pollutants which are not degraded by laccases. The application of SMCs for phthalate removal can be developed into a mycoremediation-based green and sustainable technology.

Application of K-Means Clustering Algorithm to Commercial Parameters of Pleurotus spp. Cultivated on Representative Agricultural Wastes from Province of Guayas

Data of the commercial parameters of Pleurotus ostreatus and Pleurotus djamor were analyzed using the data mining technique: K-means clustering algorithm. The parameters evaluated were: biological efficiency, crop yield ratio, productivity rate, nutritional composition, antioxidant and antimicrobial activities in the production of fruit bodies of 50 strains of Pleurotus ostreatus and 50 strains of Pleurotus djamor, cultivated on the most representative agricultural wastes from the province of Guayas: 80% sugarcane bagasse and 20% wheat straw (M1), and 60% wheat straw and 40% sugarcane bagasse (M2). The database of the parameters obtained in experimental procedures was grouped into three clusters, providing a visualization of the strains with a higher relation to each parameter (vector) measured.

Biological efficiency and nutritional composition of Pleurotus djamor cultivated on bagasse of Agave salmiana

The objective of the present study was to use molecular techniques to identify a wild mushroom isolated from A. salmiana, and then evaluate its biological efficiency, production rate, and nutritional and morphological characteristics when grown on A. salmiana bagasse with various concentrations of urea as a source of nitrogen. Two types of inoculum were employed: in grain (WG) and pellet (WP) form. The substrate was supplemented with total nitrogen concentrations (TN) of 0.77, 0.95, 1.14, 1.32, and 1.5% to evaluate its effect on the biological efficiency (BE), production rate (PR), and morphological and nutritional characteristics of the fruiting bodies. The molecular analysis of the ITS region permitted the amplification of a product of 750 pb. The mushroom was identified as Pleurotus djamor. After supplementing the substrate with urea, a BE of 70% was obtained in the sample inoculated with WG at 1.32% TN. Observations found that the TN concentration of 1.5% produced malformations in the fruiting bodies. The analysis of the sporocarps indicated a raw protein content (RP) of 15–26% and that the mushroom’s nutritional composition changed according to the inoculum utilized and the percentage of nitrogen in the substrate. This is the first report on the isolation of P. djamor on A. salmiana as an atypical substrate, and so represents an opportunity for further study and commercialization. To its chemical composition and high availability, A. salmiana bagasse is a suitable alternative substrate for cultivating edible mushrooms, specifically P. djamor.