Heat Treatment of Reishi Medicinal Mushroom (Ganoderma lingzhi) Basidiocarp Enhanced Its β-glucan Solubility, Antioxidant Capacity and Lactogenic Properties

The effect of heat treatment on dried fruiting bodies of Reishi medicinal mushroom (Ganoderma lingzhi) is investigated. Control and samples treated for 20 min at temperatures of 70, 120, 150 and 180 °C were subjected for their free radical scavenging capacity, different glucans and total phenolic content determination. The growth rate of Escherichia coli and Lactobacillus casei supplemented with control and heat-treated samples is also investigated. The roasted mushroom samples at 150 °C and 180 °C showed the highest level of β-glucan (37.82%) and free radical scavenging capacity on 2,2-diphenyl-1-picrylhidrazyl (DPPH•) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS•+). The content of total phenolics (TPC) was also influenced by heat treatment and significantly higher TPC values were recorded in samples treated at 120 °C and 150 °C. The presence of reducing sugars was only detected after heat treatment at 150 °C (0.23%) and at 180 °C (0.57%). The heat treatments at 120, 150 and 180 °C, significantly attenuated the number of colony-forming units (CFU) of pathogenic E. coli, in a linear relationship with an elevated temperature. The supplementation of heat-treated Reishi mushroom at 120 °C resulted in the highest growth rate of probiotic L. casei. The obtained results in this study revealed the significant effect of short-term heat treatment by enhancing the antioxidant capacity, β-glucan solubility and prebiotic property of the dried basidiocarp of Reishi mushroom.

Differences in Antioxidants, Polyphenols, Protein Digestibility and Nutritional Profile between Ganoderma lingzhi from Industrial Crops in Asia and Ganoderma lucidum from Cultivation and Iberian Origin

Carpophores of Ganoderma lingzhi (GZ) from industrial crops in China were analysed and compared with carpophores of three Iberian strains of cultivated Ganoderma lucidum (GL) (Aveiro, Madrid, Palencia) previously genetically characterized. The genetic determination of all the fungi in the study coincided with the identification provided by the companies and entities that supplied the samples. Cultivation time ranged between 107 and 141 days. The analysis of total phenol content showed to be 56.8% higher for GL from Palencia than for GZ. Intraspecific variation was a maximum of 56% from GL. The content of antioxidants, both intraspecific and interspecific, was found to be strain-dependent with a maximum variation of 78.5%. The nutritional analysis shows that there are differences in dietary fiber, protein, ash and sodium content between GL and GZ. In fatty acids analysis, only trans fatty acids showed significant differences, being higher in GL. Protein profile and digestibility of GZ and GL-Madrid mushroom proteins were evaluated by digestion with simulated gastric fluid and were different. The two species were perfectly differentiated according to their protein profile. These results should be considered for nutritional and industrial applications.

Microbial communities and soil chemical features associated with commercial production of the medicinal mushroom Ganoderma lingzhi in soil

Crop production, including mushroom farming, may cause significant changes to the underlying substrates which in turn, can influence crop quality and quantity during subsequent years. Here in this study, we analyzed the production of the medicinal mushroom Ganoderma lingzhi and the associated soil microbial communities and soil chemical features over 24 months from April 2015 to April 2017. This Basidiomycete mushroom, known as Lingzhi in China, is commonly found on dead trees and wood logs in temperate and subtropical forests. Its economic and medicinal importance have propelled the development of a diversity of cultivation methods. The dominant method uses wood logs as the main substrate, which after colonization by Lingzhi mycelia, are buried in the soil to induce fruiting. The soil microbial communities over the 24 months were analyzed using the Illumina HiSeq platform targeting a portion of the bacterial 16S rRNA gene and the fungal internal transcribed spacer 1 (ITS1). Overall, a significant reduction of Lingzhi yield was observed over our experimentation period. Interestingly, temporal changes in soil microbial compositions were detected during the 24 months, with the fungal community showing more changes than that of bacteria in terms of both species richness and the relative abundance of several dominant species after each fruiting. The soil chemical features also showed significant changes, with decreasing soil nitrogen and phosphorus concentrations and increasing soil pH and iron content after each fruiting. We discuss the implications of our results in sustainable Lingzhi production in soil.

Biodegradation of 1,1,1-Trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) by Mixed Cultures of White-Rot Fungus Ganoderma lingzhi and Bacterium Pseudomonas aeruginosa

This study investigated the biodegradation of 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) by mixed cultures white-rot fungus Ganoderma lingzhi BMC 9057 and bacteria Pseudomonas aeruginosa. Cultures bacteria P. aeruginosa with various volumes 1, 3, 5, 7, and 10 ml (1 ml ≈ 1.53 x 109 bacteria cells/ml cultures) was added into 10 ml G. lingzhi cultures for degrading DDT. After 7 d incubation, DDT was degraded about 100% with addition of 5, 7, and 10 ml of P. aeruginosa culture into G. lingzhi. Two metabolites; 1,1-dichloro-2,2-bis (4-chlorophenyl) ethane (DDD) and 1-chloro,2-2-bis (4-chlorophenyl) ethylene (DDMU) were detected from mixed cultures G. lingzhi and P. aeruginosa as metabolite products of DDT. This research indicated that mixed cultures of whiterot fungus G. lingzhi and P. aeruginosa could be used to degrade DDT.