Mushrooms could be used as a potential means of producing natural antioxidants and antimicrobials. To obtain fungal biomass in submerged culture is an easy and rapid method. For this reason, biomasses of Pleurotus species which grown on liquid media were used to prepare hot water extracts and their antioxidant and antibacterial properties were determined. The highest total phenolic content was determined in P. ostreatus extract (9.14 mg.g-1 dry weight of extract) whereas Pleurotus sajor-caju gave highest reading of total flavonoid content (3.10 mg.g-1 dry weight of extract). In the scavenging effect of DPPH radical test, P. sajor-caju showed the highest activity potential (69.67%). Mycelia extracts from Pleurotus species showed the antibacterial activity against the Gram negative and Gram positive bacteria (plant and human pathogens). Based on the results obtained, each extract from the five species Pleurotus (P. florida, P. citrinopileatus, P. sajor-caju, P. ostreatus and P. eryngii) showed antioxidant and antibacterial properties, and could be used in the formulation of nutraceuticals. Furthermore, the results presented in this work demonstrated that extracts were capable of inhibiting the in vitro growth of Helicobacter pylori.

Abstract:Mushrooms produce a variety of bioactive antioxidant secondary metabolites including ectins, polysaccharides, pigments, phenolic compounds, sterols and terpenes. Extracellular and intracellular compounds produced by submerged liquid fermentation are important industrially and economically. Phanerochaete chrysosporium (PC) is the model white-rot fungus that easy cultivation on lignocellulose-containing substrates. PC can be used as a bioprotein source. Aims of this study were to determine the in vitro antioxidant, cytotoxic and genotoxic effects of hot water extract obtained from PC on human peripheral blood monunuclear cells (hPBMCs). Cytotoxicity was determined by lactate dehydrogenase (LDH) leakeage assay and neutral red (NR). Total antioxidant capacity (TAC) and total oxidant status (TOS) were detected to determine the oxidative damage. Genotoxicity was characterized by micronuclei and chromosome aberrations assays for specify DNA damage. PC (5-75 µg/ml) significantly increased antioxidant capacity and these doses did not cause any significant alterations to cytotoxicity on hPBMCs. The elavated doses of PC (5-250 µg/ml) did not cause increase in genotoxic. Whereas, 250 and 500 µg/ml doses of PC statistically increased TOS levels, NR uptake, LDH release, CA/cell frequency and MN formation however decreased TAC levels. This study is the first time on cytotoxicity, genotoxicity and oxidative damage of PC on hPBMCs. In conclusion, the consumption of PC can be safe for humans, but it has also exposure period and dose-dependent effects on inducing oxidative damage and toxicity on hPBMCs.

Four linear nonphenolic diarylheptanoids were synthesized and their antibacterial activities were studied. (S)-2-Me-CBS-catalysed reduction of alnustone with BH 3 .SMe 2 gave (R) (-)(4 E ,6 E)-1,7-diphenylhepta-4,6-dien-3-ol, a natural product. Reduction of alnustone with Na in t-BuOH at-15°C under NH 3 atm gave (E)-1,7-diphenylhept-5en-3-one as a Birch-type reduction product. t-BuOK catalysed condensation of benzalacetone with propionyl chloride gave (4 Z ,6 E)-5-hydroxy-1,7-diphenylhepta-4,6-dien-3-one, a natural product. (1 E ,4 Z ,6 E)-5-Hydroxy-4-phenethyl-1,7-diphenylhepta-1,4,6-trien-3-one, a curcuminoid, was synthesized starting from pentan-2,4-dione in 3 steps. The synthesized chemical compounds were applied against 2 gram-positive bacteria (Bacillus cereus and Arthrobacter agilis), 4 gram-negative bacteria (Pseudomonas aeruginosa, Xanthomonas campestris, Klebsiella oxytoca, and Helicobacter pylori), and 1 yeast (Candida albicans) by the disc diffusion method. All of the synthesized compound exhibited different degrees of antimicrobial activity at concentrations between 20-100 µg/disc against the test organisms.

In this study, alcohol extracts of Pleurotus sajor-caju and Pleurotus ostreatus which are edible mushroom species were obtained and their extract contents were determined by GC-MS. Antioxidant capacity of these alcohol extracts were determined with 2-2-diphenyl, 1-picrylhydrazyl (DPPH). Antimicrobial activities of alcohol extracts was determined on Klebsiella oxycota, Pseudomonas aeruginosa, Staphylococcus aureus, Corynobacterium diphtheria, Enterococcus faecalis, Escherichia coli, Serratia marcescens, Bacillus cereus and Bacillus thuringiensis bacteria, and Rhodotorula glutinis and Candida albicans yeasts. Moreover, this study indicated the anti-quorum sensing activity of the tested mushroom extracts against to Chromobacterium violaceum CV026. P. sajor-caju and P. ostreatus alcohol extract compositions were determined with GC-MS. According to GC-MS results, 20 different compounds were found in P. sajor-caju and P. ostreatus alcohol extract. Hexadecanoic acid, linoleic acid, octadecanoic acid, 2,3-dihydroxypropyl ester and palmitic acid were found in both mushroom extracts. Because they contain a high content of fatty acids, alcohols, aldehydes, ketones and terpenoids, these extracts can be used both as antimicrobial, anticancerogenic, antioxidant and antiaging agents or can be consumed as food supplements.

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Fungi, an important group with a wide variety of species, shows spectacular development with their unique cell structures. Fungi survive in many different ecosystems with their reproductive abilities and metabolic features. Thanks to wide temperature and pH tolerances, fungi develop on organic and inorganic materials in all ecosystems they are in and maintain the existence of ecosystems by taking part in many cycles. However, examples of pathogens are also available. They are a group of organisms that are environmentally important, such as saprophytes and mutualists, but are pathogens for animals, especially plants. Fungi basically have two different cell structures: yeast, and molds. But some fungi have both of these structures. Depending on the temperature of the environment they are in, they can be found in yeast or mold structures, and fungi with this feature are called dimorphic fungi. Whether it is yeast, mold, or dimorphic fungi, they use their enzymes with high activity to benefit from the nutrients in the environment. Fungi can be easily grown in natural and synthetic media. Yeast can reproduce rapidly with their single-celled structure, while molds and mushrooms are very successful with their hyphae structures.

As a result of climate change and the ozone layer spoilage, harmful rays of the sun such as UV reach the world more and harm agricultural production. To be protected from the harmful effects of UV, not only human beings, but all living organisms have developed different characteristics. In recent years, pigments with radiation absorbing and antioxidant properties have been used against UV damages. In this study, the effect of carotenoid pigments obtained from bacteria and fungi on the lettuce plant (Lettuce Yedikule 5701) was investigated due to its high antioxidant and UV protection properties. Pigment solutions partially purified from microorganisms were sprayed onto the plants. While an increase was detected in the amounts of hydrogen peroxide (H2O2) and lipid peroxidation (LPO) in the lettuce plant with the effect of UV, a decrease was observed in these parameters when applied with pigment solutions. With the same application, microbial pigments protected the plant against the harmful effects of UV by increasing the antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and the amount of chlorophyll. As a result of this study; It has been determined that microbial pigments, which can be obtained easily and with low costs, have protection properties against the harmful effects of UV and provide the plants with properties to resist the stress.