Progress in biological activities and biosynthesis of edible fungi terpenoids.

The edible fungi have both edible and medicinal functions, in which terpenoids are one of the most important active ingredients. Terpenoids possess a wide range of biological activities and show great potential in the pharmaceutical and healthcare industries. In this review, the diverse biological activities of edible fungi terpenoids were summarized with emphasis on the mechanism of anti-cancer and anti-inflammation. Subsequently, this review focuses on advances in knowledge and understanding of the biosynthesis of terpenoids in edible fungi, especially in the generation of sesquiterpenes, diterpenes, and triterpenes. This paper is aim to provide an overview of biological functions and biosynthesis developed for utilizing the terpenoids in edible fungi.

Accumulation and remobilization of metals in superficial sediments in Tianjin, China.

The concentrations of Cr, Ni, Cu, Zn, Cd, and Pb in superficial sediment samples collected from three representative sites (Yuqiao Reservoir, Haihe River, and Haihe River Estuary) in Tianjin, North China, were analyzed using various single extraction and sequential extraction procedures to determine their remobilization, extractability, and distribution patterns. Sediments from the Haihe River had higher metal concentrations and geo-accumulation indices, especially for Cd and Zn, than sediments from the other two sites, suggesting that the Haihe River has been heavily influenced by anthropogenic activities. In addition, over 31% and 28.2% of the total Cd in the Haihe River and the Yuqiao Reservoir, respectively, and 18.2% of the total Zn in the Haihe River were found to be associated with the exchangeable form, indicating the significant remobilization of Cd and Zn when compared with Cr and Ni. However, over 98% of the Ni and 78% of the Cr were most closely associated with the residue and oxidizable fractions, which resulted in their becoming environmentally immobile. Based on the Environmental Protection Agency method 3050B, Cd and Zn had the greatest extraction efficiency when a single extraction procedure using 0.5-mol L(-1) HCl, 0.43-mol L(-1) HAcO, and 0.05-mol L(-1) ethylene-diamine-tetra-acetic acid was conducted, with extraction yields of up to 72%, 68%, and 56% for Cd and 50%, 49%, and 29% for Zn, respectively, being obtained for the Haihe River sediments. This was followed by the yields of Cu and Pb and, finally, those of unpolluted metals such as Cr and Ni. HCl and acetic acid extraction provided equivalent information for predicting Cd and Zn mobility in the sediments studied and produced suitable results for quick screening.

Enhancement of carotenoid production and its regulation in edible mushroom Cordyceps militaris by abiotic stresses.

Cordyceps militaris carotenoids are widely used as food additives, animal feed supplements, and so on. However, the biosynthetic pathway of carotenoids in C. militaris is still obscure. In this paper, changes of mycelial morphology and carotenoid accumulation of C. militaris were investigated under oxidative (KMnO4) and osmotic stress (NaCl). Subsequently, qRT-PCR was employed to detect the expression levels of genes related to carotenogenesis to explore the mechanism of adaptation to abiotic stress. When the concentrations of KMnO4 and NaCl were respectively 0.4 g/L and 2 g/L, carotenoid accumulation reached a maximum of 6616.82 ±â€¯666.43 µg/g and 6416.77 ±â€¯537.02 µg/g. Under the oxidative stress condition of KMnO4, the expressions of psy and hsp70 increased significantly compared with control. Besides, the genes fus3 and hog1 were significantly enriched in the MAPK signal pathway. Compared with the control group, there was no significant difference in expression of psy in the NaCl group. Moreover, the accumulation of triacylglycerols may contribute significantly to the increase in carotenoid accumulation. The increased accumulation of antioxidant carotenoids induced under environmental stress is to resist oxidative conditions. Fus3 and Hog1 signaling in the MAPK pathway was activated and subsequently take effects on the resistance of oxidative condition by regulating related metabolic processes. C. militaris resist the stress of high oxygen by producing a large amount of glycerol and carotenoids when this fungus is cultured in a saline environment for a long time.

Biosynthesis and regulation of carotenoids in Dunaliella: progresses and prospects.

Natural carotenoids are high in demand in global market owing to their widespread applications in nutrition, medicine, food coloring agent and cosmetic, as well as to the natural and healthy preference of consumers today. Some strains of Dunaliella are well known for their talent of massive beta-carotene accumulation. Content of the high bioavailability stereoisomer of beta-carotene, the 9-cis stereoisomer, is highest in Dunaliella among all the natural carotenoids sources. These valuable algae have been exploited commercially for beta-carotene-rich Dunaliella powder and natural beta-carotene in many countries since 1980s. However, drawbacks of traditional production methods have hampered the worldwide promotion of carotenoids production with Dunaliella. To shake off the dilemma, complete understanding of carotenogenic mechanism is urgent. Carotenogenic mechanism in Dunaliella is described in present paper, including carotenogenic pathway and its regulation. Generally, it seems that carotenogenic pathway in Dunaliella is close to the one of higher plants. It is known that reactive oxygen species (ROS) were involved in signal transduction for gene activation. Induction of ROS is in parallel with the enhanced beta-carotene accumulation in Dunaliella. It is suggested that ROS trigger massive carotenoids accumulation in Dunaliella. It also revealed that relation may exist between enhanced beta-carotene accumulation and lipid metabolism. For the talent of beta-carotene synthesis, it is possible that Dunaliella massively accumulates beta-carotene and other high-value carotenoids by genetic technologies.

[Spatial distribution of Se in soils from different land use types and its influencing factors within the Yanghe Watershed, China].

Based on different land use types, altitudes, soil and vegetation types etc, 171 representative topsoils (0-10 cm) were collected within the Yanghe watershed, China for determining the total concentrations, spatial distribution and influencing factors of selenium (Se). The results showed that the total selenium concentrations in soils within the watershed ranged from 0.02 to 3.24 mg x kg(-1) dry weight (dw). The geometric mean of Se in soils within the watershed was 0.30 mg x kg(-1), which was higher than those in Beijing plain (0.20 mg x kg(-1)), Hebei plain (0.19 mg x kg(-1)) and China (0.29 mg x kg(-1)). Soils which lacked Se (0.13-0.18 mg x kg(-1)) were mainly distributed in Huaian, Xuanhua, and Huailai counties. Se concentrations in most areas within the watershed were sufficient (0.18-0.45 mg x kg(-1)). In addition, Wanquan, Xinghe, Tianzhen and Yanggao counties also had some selenium-rich areas. Concentrations of Se were different under different land use types. They were of the following order: forest land > industrial and mining land > grassland > agricultural land. Agricultural land had the lowest concentrations of Se, with a mean concentration of 0.28 mg x kg(-1). We also found that parent materials and soil types had no significant effects on soil Se concentrations within the Yanghe Watershed. The results indicated that Se concentrations were positively and significantly correlated with clay contents and altitudes, but negatively and significantly with pH values. Furthermore, TOC, Fe and Al concentrations were also important factors influencing the Se concentrations in soils within the Yanghe Watershed.

In vitro antioxidant activities of the polysaccharides from Pleurotus tuber-regium (Fr.) Sing.

The antioxidant activities of two homogeneous polysaccharides, water extraction of polysaccharide (W-PTR) and alkali extraction of polysaccharide (A-PTR) from Pleurotus tuber-regium (Fr.) Sing. were evaluated. Results showed that W-PTR was stronger than A-PTR in O2(-·) scavenging activity, while A-PTR was stronger than W-PTR in the scavenging activities to ·OH, DPPH·, inhibition effects on liver lipid peroxidation, liver mitochondria swelling, and red blood cell (RBC) hemolysis. At concentration of 0.3 g/L, the O2(-·) scavenging activity of W-PTR and A-PTR were 85.7% and 71.7%. At concentration of 0.25 g/L, the ·OH scavenging activity of W-PTR and A-PTR were 64.20% and 74.97%. At the concentration of 0.3 g/L, the lipid peroxidation inhibition effects of A-PTR were 79.37%. At concentration of 0.8 g/L, the hemolysis inhibition rate of A-PTR was 77.16%. The polysaccharides of P. tuber-regium had strong antioxidant potency and might be exploited as effective natural antioxidant to alleviate oxidative stress.

Regulation effect of polysaccharides from Pleurotus tuber-regium (Fr.) on the immune activity of mice macrophages.

Pleurotus tuber-regium (Fr.) is widely consumed as a nutritious food due to its multiple health effects, especially immune function. This study was aimed at investigating its immune activity using the mice peritoneal macrophage model. Two polysaccharides, water and alkaline extraction of polysaccharides (W-PTR and A-PTR), from P. tuber-regium were used to test their immune functions and compare their possible activity differences. Results showed that both W-PTR and A-PTR showed a significant enhancement effect on the macrophage phagocytosis, and could activate the related enzymes, such as ATPases, lysozyme, and LDH, which are responsible for providing the maturation and proliferation process of macrophages with sufficient energy. In addition, levels of intracellular cytokines (IL-1, TNF-α, NO) were significantly increased after being treated with polysaccharides. A-PTR displayed a better performance than W-PTR in almost all tests. It is concluded that both polysaccharides could enhance the immune system by activating the macrophages and related enzymes, and induce the release of cytokines, indicating that polysaccharides are responsible for the immune function of Pleurotus tuber-regium (Fr.).

Characterization of water and alkali-soluble polysaccharides from Pleurotus tuber-regium sclerotia.

Pleurotus tuber-regium sclerotia, an edible and medicinal mushroom, is a rich source of polysaccharides used as a functional food to promote health and longevity. The crude polysaccharides were isolated from the P. tuber-regium by hot aqueous and alkali extraction and then further purified by DEAE-52 cellulose chromatography and Sephadex G-100 chromatography. Two polysaccharides, water and alkaline extraction of polysaccharides (W-PTR and A-PTR), were obtained and their extraction process were optimized through orthogonal array design. Structure characteristics (physicochemical property analysis, molecular weight, monosaccharide composition, sulfate and uronic acid contents, triple helical structures, ultraviolet spectrum and infrared spectroscopy) of the two polysaccharides were investigated. Results showed that the main difference between the two polysaccharides is reflected in color, solubility, molecular weight and monosaccharide composition. Conformational analysis showed that both W-PTP and A-PTP had triple-helix conformation. The 3D structure of the two polysaccharides and their structure-function relationship will be challenge in the future.

Effects of salinity changes on the growth of Dunaliella salina and its isozyme activities of glycerol-3-phosphate dehydrogenase.

Dunaliella salina could survive in media containing a wide range of NaCl concentrations ranging from about 0.05 M to saturation (around 5.5 M). Glycerol is an important osmolyte when Dunaliella survive in various salt environments, and G3pdh is a key enzyme in glycerol metabolism. The osmotic response of D. salina was investigated by studying its cell growth, glycerol content change, and isozyme activity of glycerol-3-phosphate dehydrogenase (G3pdh) in different salinities. Results showed that 2.0 M NaCl was the optimal salinity for the growth of D. salina, in which condition the highest glycerol content of 64.02 +/- 3.21 (mean +/- SD) microg/mL was detected. D. salina could rapidly increase or decrease glycerol contents to adapt to hypoosmotic or hyperosmotic environments. The glycerol content declined 52.05% when salinity was changed from 2.0 to 0.5 M NaCl, and the glycerol content increased 43.61% when salinity was increased from 2.0 to 5.0 M NaCl. In the isozyme electrophoresis assay two kinds of isozymes, G3pdh and superoxide dismutase (Sod), were detected synchronously. Interestingly, it was first found that there are five isozymes of G3pdh in D. salina. G3pdh-2 mainly takes effect in moderate to high salinities, whereas the other four isozymes take effect in low salinities, which may provide an important clue for future research on osmoregulation mechanisms.

[Distribution and enrichment of nutrients in superficial sediment in Tianjin typical waters].

Concentrations of organic matter (OM), total nitrogen (TN), total phosphorus (TP) and bioavailable phosphorus (BAP) were determined in superficial sediment (0-25 cm) collected from 4 selected typical waters (Yuqiao reservoir, Haihe River, Haihe estuary and Bohai Bay) in Tianjin, China. Pollution index (P(i)) and enrichment factors (EF) were taken to analyze nutrients enrichment and dynamic characteristic. The results show that 4 typical waters are polluted by anthropogenic source and much higher than the permissible limits which most benthos can bearing, the concentrations of OM, TN, TP and BAP are decreasing progressively by the order: Haihe River > Haihe estuary> Bohai Bay Tianjin Sea Area. EF for OM, TN, TP and BAP reaches 1.6-6.5, 0.9-2.7, 0.9-2.6 and 4.4-9.2, respectively. The concentrations of BAP in different waters are inconsistent with those of TP, the ratio of BAP to TP in Yuqiao reservoir is the biggest, 16.3%, which shows endogenous source release is serious and eutrophication is the key problems of water pollution. The concentrations of OM and BAP increase in large scale between 1988 and 2005, TP basically keeps unchanging and TN slightly increases. Around Haihe River sediment dredging, nutrient concentrations (OM, TN and TP) of superficial sediments in Haihe River reduce to 57.7%, 82.8% and 85.2% of original concentration, respectively. And sediment dredging plays a positive role in nutrients removal.

[Source and enrichment of heavy metals in sewage-irrigated area soil of Dagu Sewage Discharge Channel].

Concentrations of metals, total nitrogen, total phosphorus and organic matter were determined in topsoil (0-25 cm) and subsoil (25-50 cm) samples collected from 16 selected blocks in the sewage-irrigated area of Dagu Sewage Discharge Channel in Tianjin, China. Contamination factors (CF), relative enrichment factors (REF) and cluster analysis (CA) were taken to analyze the source and enrichment of heavy metals. The results show that the concentrations of Hg, Cd, Pb and Zn are above the 1st limit value of Environmental Quality Standard for Soils (China), while those of As, Ni and Cr are below the 1st limit value of the standard. The concentrations of Hg, Cd, Pb, Zn, As, Ni and Cr in topsoil are 0.323, 0.341, 44.7, 108.29, 11.2, 29.86 and 66.6 mg/kg, respectively. CF and REF of Hg in topsoil are 10.8 and 7.2, respectively, which indicates very high contamination and moderately severe enrichment. Both factors of Cd are 3.8 and 4.5, and indicate considerable contamination and moderate enrichment. Those of Pb, Zn and As are all less than three, which indicates moderate contamination and minor enrichment. As for Ni and Cr, their contamination is low and no enrichment occurs. REF for Hg, Pb and Zn in topsoil is relatively higher than that in subsoil while As in subsoil is higher. When compared with data measured in 1985, the concentrations of Cd and As increase while those of Hg, Pb and Zn decrease. Furthermore, measures, including CA and in situ investigation, are taken to identify the main sources of heavy metal contamination, and it shows that Hg and As contamination result from anthropogenic effect as well as deposition of coal combustion. Cd, Zn and Pb contamination are mainly from sewage irrigation, and atmosphere deposition also makes certain contribution. Ni and Cr contamination are attributed to natural sources.

[Concentrations and distribution of heavy metals in urban sewage discharge channel of Tianjin].

Concentrations of metals, organic matter(OM), total nitrogen (TN) and total phosphorus (TP) were determined in sediment and soil samples collected from 15 selected sites along Dagu sewage discharge channel in Tianjin, China. Relative enrichment factors and correlation analysis were taken to study the distribution and pollution level of metals. The results show that pollution level is more serious in sediment than that in soil. Hg, Cd, Zn and Pb are more enriched while Cr, Ni and As are less enriched. Relative enrichment factors (REF) of Hg, Cd, Zn and Pb in sediment are 59.3, 25.4, 14.5 and 7.5, and that in soil are 8.44, 5.19, 6.6 and 3.3, respectively. The heavy metal concentrations greatly vary among different sampling sites, which is demonstrated by the fact that coefficient of variation (CV) varies from 74.4% to 110.8% in sediment. The highest enrichments of heavy metals are found in sampling site S4 and S12, which are affected by chemical industry wastewater. There is no significant correlation between metal concentrations in sediment and those in soil. The concentrations of heavy metals in sediment are not reciprocally correlated, either. However, significant correlations exist among many pollutants in soil. Hg, Cd, Zn and Pb are positively correlated with each other, at the same time they are positively correlated with OM, TN and TP, but Cr, Ni and As are poorly correlated with OM and TP, which suggests that Cd, Zn and Pb have similar environmental geochemical properties and are contaminated by anthropogenic impact. When compared with the main rivers in Tianjin, the enrichment of heavy metals in Dagu sewage discharge channel is relatively high.