Bioactive Properties of Mushroom (Agaricus bisporus) Stipe Extracts

The antibacterial activity and total phenolic (TP) content of Agaricus bisporus stipes were assessed using solvent and water extracts to determine its bioactivity. Extraction methods included accelerated solvent extraction (ASE) and hot water followed by membrane concentration. Water extract from ASE had the highest TP of 1.08 gallic acid equivalents (GAE)/g dry weight (DW) followed by ethanol at 0.61 mg GAE/g DW and 0.11 mg GAE/g DW for acetone. Acetone extracts inhibited Escherichia coli and Staphylococcus aureus at less than 50%; ethanol inhibited E. coli at 61.9% and S. aureus at 56.6%; and ASE water inhibited E. coli at 78.6% and S. aureus at 65.4%. The TP content of membrane concentrated extract of mushroom was 17 mg GAE in 100 mL. Membrane concentrated water extracts had a higher percentage inhibition on S. aureus than E. coli. Overall, the results were promising for further application of mushroom stipe extracts as a functional food additive. Practical Applications Mushrooms are known for their health benefits and have been identified as a good source of nutrients. The highly perishable nature of mushrooms warrants further processing and preservation to minimize losses along the supply chain. This study explores the possibility of adding value to mushroom stipes, a by-product of the fresh mushroom industry. The extracts assessed indicate the antibacterial activity and phenolic content, and the potential of using these extracts as functional ingredients in the food industry. This study provides valuable information to the scientific community and to the industries developing novel ingredients to meet the market demand for natural food additives.

Bioactive Properties of Mushroom (Agaricus bisporus) Stipe Extracts

The antibacterial activity and total phenolic (TP) content of Agaricus bisporus stipes were assessed using solvent and water extracts to determine its bioactivity. Extraction methods included accelerated solvent extraction (ASE) and hot water followed by membrane concentration. Water extract from ASE had the highest TP of 1.08 gallic acid equivalents (GAE)/g dry weight (DW) followed by ethanol at 0.61 mg GAE/g DW and 0.11 mg GAE/g DW for acetone. Acetone extracts inhibited Escherichia coli and Staphylococcus aureus at less than 50%; ethanol inhibited E. coli at 61.9% and S. aureus at 56.6%; and ASE water inhibited E. coli at 78.6% and S. aureus at 65.4%. The TP content of membrane concentrated extract of mushroom was 17 mg GAE in 100 mL. Membrane concentrated water extracts had a higher percentage inhibition on S. aureus than E. coli. Overall, the results were promising for further application of mushroom stipe extracts as a functional food additive. Practical Applications Mushrooms are known for their health benefits and have been identified as a good source of nutrients. The highly perishable nature of mushrooms warrants further processing and preservation to minimize losses along the supply chain. This study explores the possibility of adding value to mushroom stipes, a by-product of the fresh mushroom industry. The extracts assessed indicate the antibacterial activity and phenolic content, and the potential of using these extracts as functional ingredients in the food industry. This study provides valuable information to the scientific community and to the industries developing novel ingredients to meet the market demand for natural food additives.

Oyster mushroom waste as manure in fish culture: a preliminary study

In an attempt to recycle the waste substrates of the oyster-mushroom crop, tanks were stocked with seed of Indian major carp Cirrhinus mrigala at the rate of 600,000/ha and waste substrate was applied at weekly interval at 0, 50, 100, 150, 200 and 250 g/tank. Oyster mushroom waste not only provided highly nutritive colonised detritus to the fish as direct feed, but also produced rich plankton in the tank. In waste treated tanks, production was better than in the control in 150, 200 and 250 g/tank treatment suggesting the possibility of fish-oyster mushroom integration.

Mushroom: An Oracular Sound Processor

Composers of digital music today have a bewildering variety of sound-processing tools and techniques at their disposal. At their best, these tools allow composers to hone a sound to perfection. However, they can also lead us into a routine which bypasses avenues of experimentation, simply because the known tools work so well and their sonic output is so attractive. An alternative strategy is oracular sound processing. An oracular sound processor creates a derived version of its input whose characteristics could not have been fully predicted, while affording the user little or no parametric control over the process.

Intoxication par les champignons [Mushroom poisoning].

Mushroom poisoning is a regular complaint for consultation in emergency facilities. These situations are usually benign and symptomatic treatment is sufficient. However, severe damage can occur, potentially life-threatening. We review the various syndromes associated with the toxins involved, their management and the major signs that are suggestive of serious injury and requiring hospitalization.

The significance of volatile antifungal metabolites produced by trichomerma harzianum biotype Th4, in green-mould disease of commercial mushroom crops /

The aggressive mushroom competitor, Trichoderma harzianum biotype Th4, produces volatile antifungal secondary metabolites both in culture and during the disease cycle in compost. Th4 cultures produced one such compound only when cultured in the presence of Agaricus bisporus mycelium or liquid medium made from compost colonised with A. bisporus. This compound has TLC and UVabsorption and characteristics indicating that it belongs to a class of pyrone antibiotics characterised from other T. harzianum biotypes. UV absorption spectra indicated this compound was not 6-pentyl-2H-pyran-one (6PAP), the volatile antifungal metabolite widely described in Th1. Furthermore, this compound was not produced by Th1 under any culture conditions. Mycelial growth of A. bisporus, Botrytis cinerea and Sclerotium cepivorum was inhibited in the presence of this compound through volatility , diffusion and direct application. This indicates that Th4 produces novel, volatile, antifungal metabolites in the presence of A. bisporus that are likely involved in green mould disease of mushroom crops.

Diversity among bacteria causing blotch disease on the commercial mushroom, agaricus bisporus /

A total of 251 bacterial isolates were isolated from blotched mushroom samples obtained from various mushroom farms in Canada. Out of 251 stored isolates, 170 isolates were tested for pathogenicity on Agaricus bisporus through mushroom rapid pitting test with three distinct pathotypes observed: dark brown, brovm and yellow/yellow-brown blotch. Phenotypic analysis of 83 isolates showed two distinct proteinase K resistant peptide profiles. Profile group A isolates exhibited peptides with masses of 45, 18, 16 and 14 kDa and fiirther biochemical tests identified them as Pseudomonasfluorescens III and V. Profile group B isolates lacked the 16-kDa peptide and the blotch causing bacterial isolates of this group was identified as Serratia liquefaciens and Cedecea davisae. Comparative genetic analysis using Amplified Fragment Length Polymorphism (AFLP) on 50 Pseudomonas sp. isolates (Group A) showed that various blotch symptoms were caused by isolates distributed throughout the Pseudomonas sp. clusters with the exception of the Pseudomonas tolaasii group and one non-pathogenic Pseudomonas fluorescens cluster. These results show that seven distinct Pseudomonas sp. genotypes (genetic clusters) have the ability to cause various symptoms of blotch and that AFLP can discriminate blotch causing from non-blotch causing Pseudomonasfluorescens. Therefore, a complex of diverse bacterial organisms causes bacterial blotch disease

An unusual postharvest spotting disease of the comercial mushroom, Agaricus bisporus, caused by a novel pathovar of Pseudomonas tolaasii

An unusual postharvest spotting disease of the commercial mushroom, Agaricus bisporus, which was observed on a commercial mushroom farm in Ontario, was found to be caused by a novel pathovar of Pseudomonas tolaasii. Isolations from the discoloured lesions, on the mushroom pilei, revealed the presence of several different bacterial and fungal genera. The most frequently isolated genus being Pseudomonas bacteria. The most frequently isolated fungal genus was Penicillium. Of the bacteria and fungi assayed for pathogenicity to mushrooms, only Pseudomonas tolaasii was able to reproduce the postharvest spotting symptom. This symptom was typically reproduced 1 to 7 days postharvest, when mushroom pilei were inoculated with 101 to 105 cfu. Of the fungi tested for pathogenicity only a Penicillium sp. and Verticillium fungicola were shown to be pathogenic, however, neither produced the postharvest spotting symptom. The Pseudomonas tolaasii strain isolated from the postharvest lesions differed from a type culture (Pseudomonas tolaasii ATCC 33618) in the symptoms it produced on Agaricus bisporus pilei under the same conditions and at the same inoculum concentration. It was therefore designated a pathovar. This strain also differed from the type culture in its cellular protein profile. Neither the type culture, nor the mushroom pathogen was found to contain plasmid DNA. The presence of plasmid DNA is therefore not responsible for the difference in pathogenicity between the two strains.

Studies on physicochemical and biological properties of protease inhibitor from edible mushroom Pleurotus floridanus

Protease inhibitors are found abundantly in numerous plants, animals and microorganisms, owing their significance to their application in the study of enzyme structures, reaction mechanisms and also their utilization in pharmacology and agriculture. They are (synthetic/natural) substances that act directly on proteases to lower the catalytic rate. Although most of these inhibitory proteins are directed against serine proteases, some target cysteine, aspartyl or metalloproteases (Bode and Huber, 1992). Protease inhibitors are essential for regulating the activity of their corresponding proteases and play key regulatory roles in many biological processes. Applications of protease inhibitors are intimately connected to the proteases they inhibit; an overview of proteases with the modes of regulation of their proteolytic activity is discussed

“Studies on extracellular enzyme production during growth of Pleurotus sp. on lignocellulosic agriwaste and the utilization of spent mushroom substrate”

Commercially, Pleurotus spp. of mushroom are cultivated in bags. After mushroom cultivation, spent substrate remains as residual material. Proper recycling of spent substrate is beneficial for our economy. Spent substrate can be utilized for various other value added purposes through the proper knowledge of its components. Composition of various components depends on the activity of extracellular enzymes in the spent substrate. The present study was conducted to know the enzyme profile of some major extracellular enzymes - cellulase, hemicellulase (xylanase), pectinase and ligninase (lignin peroxidase and laccase) and to estimate cellulose, hemicellulose, pectin and lignin in the substrate. The use of spent substrate as a source of fibre and ethanol, and in the biodegradation of phenol by Pleurotus spp. was also investigated