Effect of cultivation conditions on ligninolytic enzyme production by Ganoderma carnosum

Ganoderma carnosum has been found in Europe only, at coniferous trees and it is difficult to distinguish it morphologically from G. lucidum. Since G. carnosum has not been studied biochemically yet, the aim of this study was to analyse its ability to produce Mn-dependent peroxidase (MnP), versatile peroxidase (VP) and laccase (Lac) under conditions of solid-state fermentation of selected plant raw materials as carbon sources, in the presence of different nitrogen concentrations in the medium. Wheat straw, corn stem, oak and grapevine sawdust were the analysed plant raw materials. Nitrogen source in synthetic medium was NH4NO3 and its concentrations were: 10mM N and 20 mM N. Enzyme activity was determined spectrophotometrically, using ABTS and phenol red, as the substrates for Lac and Mn-oxidizing peroxidases, respectively. Maximum level of MnP activity (56.82 U/l) was obtained in the medium with wheat straw and nitrogen concentration of 10 mM. Best carbon source for VP production was grapevine sawdust at nitrogen concentration of 10 mM (80.80 U/l). The obtained Lac activity was very low in the medium with wheat straw (1.80 U/l), while it was not detected in the presence of other three analyzed plant raw materials. Maximum of total protein content (0.06 mgml-1) was noted in the medium where oak sawdust was carbon source and nitrogen concentration was 20 mM.Vrste roda Ganoderma su producenti mnogih biološki aktivnih supstanci pa su objekti proučavanja mnogih medicinskih i farmaceutskih studija. U novije vreme se sve više pažnje poklanja upoznavanju njihovog ligninolitičkog enzimskog sistema, u cilju uspešne primene u različitim biotehnološkim procesima. Za razliku od G. lucidum, čiji je ligninolitički sistem intenzivno proučavan, ostale vrste ovog roda su retko bile objekti istraživanja. G. carnosum se teško morfološki razlikuje od G. lucidum. i još uvek nije biohemijski proučena, pa je cilj našeg istraživanja bio analiza produkcije Mn-oksidujućih peroksidaza i lakaza u uslovima čvrste kultivacije, na različitim biljnim ostacima (pšenična slama, stabljike kukuruza, piljevina hrasta i vinove loze) u prisustvu azota u obliku NH4NO3 i u koncentracijama od 10 mM, odnosno 20 mM. Maksimum produkcije Mn-zavisne peroksidaze dobijen je na pšeničnoj slami pri koncentraciji azota od 10 mM (56.82 U/l). Piljevina vinove loze i koncentracija azota od 10 mM bili su optimalni za sintezu verzatil peroksidaze (80.80 U/l). Dobijena aktivnost lakaza je bila izuzetno niska u medijumu sa pšeničnom slamom (1.80 U/l), dok na ostalim biljnim ostacima nije zabeležena. Maksimalni sadržaj ukupnih proteina je bio najveći u medijumu sa piljevinom hrasta kao izvorom ugljenika i koncentracijom azota od 10 mM.Projekat ministarstva br. 14304

WHEAT STRAW CONVERSION BY ENZYMATIC SYSTEM OF GANODERMA LUCIDUM

The purpose of this study was to resolve the question of whether various nitrogen sources and concentrations affect characteristics of selected G. lucidum ligninolytic enzymes participating in wheat straw fermentation. This is the first study reporting the presence of versatile peroxidase activity in crude extract of G. lucidum culture, as well as isoforms profile of Mn-oxidizing peroxidases. NH4NO3 was the optimum nitrogen source for laccase and Mn-dependent peroxidase activity, while peptone was the optimum one for versatile peroxidase activity. Four bands with laccase activity were obtained by native PAGE and IEF separations from medium enriched with inorganic nitrogen source, and only two bands from medium containing organic source. Medium composition was not shown to affect isoenzyme patterns of Mn-oxidizing peroxidases. Four isoforms of Mn-dependent peroxidase and three of versatile peroxidase were obtained on native PAGE. By IEF separation, five isoforms of Mn-dependent peroxidase and only two of versatile peroxidase were observed. The results demonstrated that G. lucidum has potential for mineralization and transformation of various agricultural residues and should take more significant participation in large-scale biotechnological processes

Effect of cultivation conditions on ligninolytic enzyme production by Ganoderma carnosum

Ganoderma carnosum has been found in Europe only, at coniferous trees and it is difficult to distinguish it morphologically from G. lucidum. Since G. carnosum has not been studied biochemically yet, the aim of this study was to analyse its ability to produce Mn-dependent peroxidase (MnP), versatile peroxidase (VP) and laccase (Lac) under conditions of solid-state fermentation of selected plant raw materials as carbon sources, in the presence of different nitrogen concentrations in the medium. Wheat straw, corn stem, oak and grapevine sawdust were the analysed plant raw materials. Nitrogen source in synthetic medium was NH4NO3 and its concentrations were: 10mM N and 20 mM N. Enzyme activity was determined spectrophotometrically, using ABTS and phenol red, as the substrates for Lac and Mn-oxidizing peroxidases, respectively. Maximum level of MnP activity (56.82 U/l) was obtained in the medium with wheat straw and nitrogen concentration of 10 mM. Best carbon source for VP production was grapevine sawdust at nitrogen concentration of 10 mM (80.80 U/l). The obtained Lac activity was very low in the medium with wheat straw (1.80 U/l), while it was not detected in the presence of other three analyzed plant raw materials. Maximum of total protein content (0.06 mgml-1) was noted in the medium where oak sawdust was carbon source and nitrogen concentration was 20 mM.Vrste roda Ganoderma su producenti mnogih biološki aktivnih supstanci pa su objekti proučavanja mnogih medicinskih i farmaceutskih studija. U novije vreme se sve više pažnje poklanja upoznavanju njihovog ligninolitičkog enzimskog sistema, u cilju uspešne primene u različitim biotehnološkim procesima. Za razliku od G. lucidum, čiji je ligninolitički sistem intenzivno proučavan, ostale vrste ovog roda su retko bile objekti istraživanja. G. carnosum se teško morfološki razlikuje od G. lucidum. i još uvek nije biohemijski proučena, pa je cilj našeg istraživanja bio analiza produkcije Mn-oksidujućih peroksidaza i lakaza u uslovima čvrste kultivacije, na različitim biljnim ostacima (pšenična slama, stabljike kukuruza, piljevina hrasta i vinove loze) u prisustvu azota u obliku NH4NO3 i u koncentracijama od 10 mM, odnosno 20 mM. Maksimum produkcije Mn-zavisne peroksidaze dobijen je na pšeničnoj slami pri koncentraciji azota od 10 mM (56.82 U/l). Piljevina vinove loze i koncentracija azota od 10 mM bili su optimalni za sintezu verzatil peroksidaze (80.80 U/l). Dobijena aktivnost lakaza je bila izuzetno niska u medijumu sa pšeničnom slamom (1.80 U/l), dok na ostalim biljnim ostacima nije zabeležena. Maksimalni sadržaj ukupnih proteina je bio najveći u medijumu sa piljevinom hrasta kao izvorom ugljenika i koncentracijom azota od 10 mM.Projekat ministarstva br. 14304

High annual radon concentration in dwellings and natural radioactivity content in nearby soil in some rural areas of Kosovo and Metohija

Some previous studies on radon concentration in dwellings of some areas of Kosovo and Metohija have revealed a high average radon concentration, even though the detectors were exposed for three months only. In order to better design a larger study in this region, the annual measurements in 25 houses were carried out as a pilot study. For each house, CR-39-based passive devices were exposed in two rooms for the two consecutive six-month periods to account for seasonal variations of radon concentration. Furthermore, in order to correlate the indoor radon with radium in nearby soil and to improve the knowledge of the natural radioactivity in the region, soil samples near each house were collected and 226Ra, 232Th, 40K activity concentration were measured. The indoor radon concentration resulted quite high from the average (163 Bq/m3) and generally it did not differ considerably between the two rooms and the two six-month periods. The natural radionuclides in soil resulted to be distributed quite uniformly. Moreover, the correlation between the226Ra content in soil and radon concentration in dwellings resulted to be low (R2=0.26). The annual effective dose from radon and its short-lived progeny (5.5 mSv, in average) was calculated by using the last ICRP dose conversion factors. In comparison, the contribution to the annual effective dose of outdoor gamma exposure from natural radionuclides in soil is nearly negligible (66 mSv). In conclusion, the observed high radon levels are only partially correlated with radium in soil; moreover, a good estimate of the annual average of radon concentration can be obtained from a six-month measurement with a proper choice of exposure period, which could be useful when designing large surveys

Antioxidative and antimicrobial potentials of Parmelia saxatilis and Pseudoevernia furfuracea

Even though numerous lichen species possess significant medical potentials they are still unexplored, and particularly species and strains originating from Serbia. Therefore, the aim of this study was to evaluate the antioxidative and antimicrobial potential of ethanol extracts of Parmelia saxatilis and Pseudoevernia furfuracea collected in Serbia. The tested extracts were good scavengers of DPPH radicals, with capacities ranging from 14.76% to 79.76% in P. saxatilis and from 21.39% to 90.04% in P. furfuracea. In P. saxatilis level of DPPH• neutralisation was highly correlated with phenol content (r2 = 0.9981) and in P. furfuracea with amount of total flavonoides (r2 = 0.9641). The extract of P. furfuracea inhibited the growth of all tested microorganisms with exception of Aspergillus flavus, while P. saxatilis extract affected only growth of bacterial species. Among tested microorganisms, Staphylococcus aureus and Klebsiella pneumoniae were the most sensitive, while Enterococcus faecalis, Pseudomonas aeruginosa as well as micromycetes were the least sensitive to tested extracts. Because of these potentials and the fact that their long term usage does not have any negative side effects on organism and development of microbial resistance, the extracts could be included in conventional therapy. [Projekat Ministarstva nauke Republike Srbije, br. 173032

Ganoderma lucidum - from tradition to modern medicine

Ganoderma lucidum has a long tradition of use in folk medicine of the Far East, which is documented in the oldest Chinese pharmacopoeia, written in the first century B.C, declaring it a superior medicine. The healing properties of G. lucidum reflected on folk names such as: Reishi, Mannentake, Ling Zhi etc., which mean “herb of spiritual power”, “mushroom of immortality” or “10,000-year mushroom”, respectively. It has been known, for thousands of years, that this species extends life span, increases youthful vigour and vitality and it was used in the treatments of hepatitis, kidneys’ disease, hypertension, arthritis, asthma, bronchitis, arteriosclerosis, ulcers and various types of cancer. However, Western civilisation did not discover its healing properties until the 20th century. Modern scientific researches and numerous clinical trails, conducted in recent decades, have confirmed the ancient knowledge of Eastern nations and given them a scientific basis. These studies have demonstrated many biological activities of G. lucidum extracts and compounds, including: immunomodulating, antioxidative, cytotoxic, hypoglycaemic, anti-inflammatory, antiallergic, antimicrobial, etc. It has been reported that its extracts play important role in detoxification of the body and protecton of the liver, as well as in reducing cardiovascular problems, stress and anxiety. However, its most important effect is undoubtedly immunostimulating one as it is the basis of many other positive effects. The Japanese government introduced G. lucidum on the official list of auxiliary agents for the treatments of various cancers, Alzheimer’s disease, diabetes and chronic bronchitis. Many chemical components have been isolated from G. lucidum, but polysaccharides and terpenoids are the main carriers of its bioactivities

Ligninolytic enzyme production in Pleurotus eryngii depending on the medium composition and cultivation conditions

Pleurotus eryngii produced laccase (Lac) both under conditions of submerged fermentation (SF) and solid-state fermentation (SSF) using all of the investigated carbon and nitrogen sources, while significant peroxidases production occurred only under SSF conditions. The highest levels of Lac activity were found under SF conditions of dry ground mandarine peels (999.5 U/l). After purification of extracellular crude enzyme mixture of P. eryngii which was grown under SF conditions with dry ground mandarine peels it was revealed two peaks of Lac activity and one peak of activity against phenol red in absence of external Mn2+ which was very low (1.4 U/l). Results obtained by purification also showed that the levels of phenol red oxidation in absence of external Mn2+ were higher than phenol red oxidation levels in presence of external Mn2+. In the medium with the best carbon source for Lac production (dry ground mandarine peels), (NH4)2SO4, with a nitrogen concentration of 20 mM, was the most optimum nitrogen source among 8 investigated sources

Intraspecific Diversity within Ganoderma lucidum in the Production of Laccase and Mn-Oxidizing Peroxidases During Plant Residues Fermentation

Comparison of the potential for laccase and Mn-oxidizing peroxidases synthesis by ten strains of Ganoderma lucidum, originating from different worldwide areas, during solid-state fermentation of selected plant raw materials was the aim of this study. The great intraspecific variability in the production of analyzed enzymes as well as the dependence of the enzyme activity on plant raw materials were reported. The strain HAI 957 was the best laccase producer in the presence of corn stem, as a unique carbon source (129.46 U/L). The highest level of Mn-dependent peroxidase activity was noted after wheat straw fermentation by G. lucidum HAI 246 (78.64 U/L), while the maximal versatile peroxidase production (59.72 U/L) was observed in strain HAI 957 in the medium with oak sawdust.Ministry of Science and Technological Development of Serbia [143041

Intraspecific Diversity within Ganoderma lucidum in the Production of Laccase and Mn-Oxidizing Peroxidases During Plant Residues Fermentation

Comparison of the potential for laccase and Mn-oxidizing peroxidases synthesis by ten strains of Ganoderma lucidum, originating from different worldwide areas, during solid-state fermentation of selected plant raw materials was the aim of this study. The great intraspecific variability in the production of analyzed enzymes as well as the dependence of the enzyme activity on plant raw materials were reported. The strain HAI 957 was the best laccase producer in the presence of corn stem, as a unique carbon source (129.46 U/L). The highest level of Mn-dependent peroxidase activity was noted after wheat straw fermentation by G. lucidum HAI 246 (78.64 U/L), while the maximal versatile peroxidase production (59.72 U/L) was observed in strain HAI 957 in the medium with oak sawdust.Ministry of Science and Technological Development of Serbia [143041

Evaluation of heavy metals and radionuclides in fish and seafood products

Despite the existence of a legislation regarding food contaminants, food safety control in Serbia is a matter of great concern. This study investigates the radioactivity levels and heavy metal concentrations in fish and seafood commercially available in Serbian markets. Domestic fish species (caught in the Danube River)and fishery products imported from Europe, Asia and America were analyzed. The content of natural radionuclides and 137 Cs were investigated by gamma spectrometry. Activity concentration of 40 K was measured in the range of 44–165 Bq kg −1 ; low levels of 137 Cs were detected in two samples (2.8 and 3.0 Bq kg −1 ), while concentrations of 226 Ra and 232 Th were below minimal detectable values. Concentrations of heavy metals (Cd, Hg and Pb)were determined using ICP-OES method. Cd concentration ranged from 0.01 to 0.81 mg kg −1 in sea fish and from 0.01 to 0.03 mg kg −1 in freshwater fish. Hg concentrations were in the range of 0.01–1.47 mg kg −1 ; the highest value was measured in the predator fish - shark. The highest level of Pb (6.56 mg kg −1 )was detected in a blue sea fish (Atlantic mackerel). The health risks associated with the intake of heavy metals and radionuclides via fish consumption were evaluated. The results indicate that fish and seafood consumption do not pose a significant health concern in the case of the usual consumption rate which is typical for the population of Serbia. However, a highly frequent consumption of fishery products can have adverse health effects, especially due to Hg and Pb contamination.Peer-reviewed version: [http://cer.ihtm.bg.ac.rs/handle/123456789/2944