The effects of quorum sensing molecule farnesol on the yield and activity of extracellular polysaccharide from Grifola frondosa in liquid fermentation.

A strategy by exogenous addition of quorum sensing molecule farnesol to improve the production, antioxidant activity and antitumor activity of extracellular polysaccharide (EPS) of Grifola frondosa by liquid fermentation was proposed in the study. The highest yield of EPS induced by farnesol was 1.25 g/L, which was 150% higher than that of the control. Four polysaccharides including EPS-C-0M, EPS-C-0.2M, EPS-F-0M and EPS-F-0.2M were extracted and purified under the conditions of control and farnesol respectively. The physicochemical properties, antioxidant activities and antitumor activities were studied. Their chemical composition differed in sugar, protein and uronic acid contents, and they were composed of six constituent monosaccharides with different ratios, with the average molecular weights of 1.12 × 103, 1.89 × 103, 1.41 × 103 and 2.02 × 103 kDa, respectively. They presented similar FT-IR spectra, but different surface morphology. Antioxidant experiments showed that they had strong scavenging activities on ABTS+, hydroxyl radical, O2- and DPPH radical. Antitumor experiments showed that they had strong inhibitory effects on human cervical cancer (HeLa) cells and human liver cancer cells (HepG2) cells. Among the four polysaccharides, EPS-F-0.2M showed the highest antioxidant and antitumor activities, indicating that farnesol could regulate the biological activity of EPS by affecting structure and properties. These results demonstrated that appropriate adjustment of culture conditions had potential application in the development of polysaccharides with high antioxidant and antitumor activity. It provided a new strategy to enhance the production and bioactivity of edible and medicinal fungal polysaccharides by using quorum sensing molecules.

UDP-glucose pyrophosphorylase gene affects mycelia growth and polysaccharide synthesis of Grifola frondosa.

To elucidate potential roles of UDP-glucose pyrophosphorylase (UGP) in mycelial growth and polysaccharide synthesis of Grifola frondosa, a putative 2036-bp UDP-glucose pyrophosphorylase gene gfugp encoding a 53.17-kDa protein was cloned and re-annotated. Two dual promoter RNA silencing vectors of pAN7-iUGP-P-dual and pAN7-iUGP-C-dual were constructed to down-regulate gfugp expression by targeting its promoter or conserved functional sequences, respectively. Results showed that silence of gfugp promoter sequence had a higher down-regulating efficiency with slower mycelial growth and polysaccharide production than those of conserved sequence. The monosaccharide compositions/percentages of mycelial and exo-polysaccharides significantly changed with the increase of galactose and arabinose contents possibly due to block of UDP-glucose supply by gfugp silence and alteration of sugar metabolism via up-regulation of UDP-glucose-4-epimerase (gfuge) and UDP-xylose-4-epimerase (gfuxe) transcription. Our findings would provide a reference to know the biosynthesis pathway of mushroom polysaccharides and improve their production by metabolic regulation.

Addition of Zeolites to Improve the Functional Characteristics of the Hen of the Wood or Maitake Medicinal Mushroom, Grifola frondosa (Agaricomycetes).

Kaolinite and the modified natural zeolite minazel plus (M+) were used as supplements in substrate used for the production of the medicinal mushroom Grifola frondosa. Growth stimulation, expressed as yield and biological efficiency, was observed when M+ (1%) was added. The production cycle was shortened by half as a result of the zeolites' ion-exchange ability, stimulation of enzyme activity, and water retain capacity. Inductively coupled plasma optical emission spectrometry of fruiting bodies showed the absence of heavy metals (arsenic, cadmium, and lead), whereas the concentration of calcium increased greatly and the concentrations of iron, magnesium, and zinc increased moderately under the influence of M+. Solid-state nuclear magnetic resonance showed a positive impact on the ß-glucan ratio, which could have been caused by the epimerization reaction stimulated by zeolites. The functionality of the mushroom was evaluated through several antioxidant activity assays, and in all cases a positive effect was established: M+ was statistically more effective in comparison with kaolinite. A strong correlation was established between the antioxidative activity of cultivated fruiting bodies and the tested compounds (total phenolic compounds, carbohydrates, and minerals).

A novel breeding strategy for new strains of Hypsizygus marmoreus and Grifola frondosa based on ligninolytic enzymes.

A novel breeding strategy for new strains of Hypsizygus marmoreus and Grifola frondosa using ligninolytic enzymes as markers was evaluated with the detection and analysis of activities and composition of 15 edible fungi. The results showed that the activity and composition of ligninolytic enzyme system varied in response to changes of fungal strains. By analyzing the growth rate of mycelia and their ability to produce ligninolytic enzymes, H. marmoreus and P. geesteranus, G. frondosa and P. sajor-caju were screened for further study. Three colonies of 26 regenerated colonies of H. marmoreus and P. geesteranus protoplast fusion and one colony of 48 regenerated colonies of G. frondosa and P. sajor-caju were selected respectively. At the same time, these four strains were identified using RAPD and ISSR molecular markers. The results showed that the strains HM5G1 and PS7F1 are new strains and have low similarity to parental strains H. marmoreus and G. frondosa. These results are supported by the results of antagonism tests. These two fusants were significantly higher in their ligninolytic enzyme activity than H. marmoreus and G. frondosa. The growth rates of strains HM5G1and PS7F1 were also noticeably higher than those of H. marmoreus and G. frondosa, by 1.36 and 1.5 times respectively. The biological efficiency of the strain HM5G1 was 11.5% higher than that of the parental strain H. marmoreus. This work suggests that it is an efficient way of breeding new strains to use the decolorization of ligninolytic enzymes as a preliminary screening marker.

Integrating dietary supplements into cancer care.

Many studies confirm that a majority of patients undergoing cancer therapy use self-selected forms of complementary therapies, mainly dietary supplements. Unfortunately, patients often do not report their use of supplements to their providers. The failure of physicians to communicate effectively with patients on this use may result in a loss of trust within the therapeutic relationship and in the selection by patients of harmful, useless, or ineffective and costly nonconventional therapies when effective integrative interventions may exist. Poor communication may also lead to diminishment of patient autonomy and self-efficacy and thereby interfere with the healing response. To be open to the patient's perspective, and sensitive to his or her need for autonomy and empowerment, physicians may need a shift in their own perspectives. Perhaps the optimal approach is to discuss both the facts and the uncertainty with the patient, in order to reach a mutually informed decision. Today's informed patients truly value physicians who appreciate them as equal participants in making their own health care choices. To reach a mutually informed decision about the use of these supplements, the Clinical Practice Committee of The Society of Integrative Oncology undertook the challenge of providing basic information to physicians who wish to discuss these issues with their patients. A list of leading supplements that have the best suggestions of benefit was constructed by leading researchers and clinicians who have experience in using these supplements. This list includes curcumin, glutamine, vitamin D, Maitake mushrooms, fish oil, green tea, milk thistle, Astragalus, melatonin, and probiotics. The list includes basic information on each supplement, such as evidence on effectiveness and clinical trials, adverse effects, and interactions with medications. The information was constructed to provide an up-to-date base of knowledge, so that physicians and other health care providers would be aware of the supplements and be able to discuss realistic expectations and potential benefits and risks.

Study of mycelial growth and bioactive polysaccharide production in batch and fed-batch culture of Grifola frondosa.

The fermentation of Grifola frondosa was investigated in the shake flasks and a 5-L jar fermenter in batch and fed-batch modes. In the shake-flask experiments, the preferable mycelial growth and exopolysaccharide (EPS) production was observed at relatively low pH; maltose and glucose were preferred carbon sources for high mycelial production. The EPS was doubled after 13 d of cultivation when glucose was increased from 2% to 4%. Yeast extract (YE) (0.4%) in combination with corn steep powder (CSP) (0.6%) and YE (0.8%) in combination with CSP (1.2%) were preferred nitrogen sources for high mycelial production and EPS production, respectively. All plant oils tested significantly stimulate cell growth of G. frondosa but they failed to enhance EPS production. The EPS products usually consisted of two fractions of different molecular sizes varied by the plant oils used. The fed-batch fermentation by glucose feeding was performed when the glucose concentration in the medium was lower than 0.5% (5g/L), which greatly enhanced the accumulation of mycelial biomass and EPS; the mycelial biomass and EPS were 3.97g/L and 1.04g/L before glucose feeding, which reached 8.23g/L and 3.88g/L at 13 d of cultivation. In contrast, the mycelial biomass and EPS in the batch fermentation were 6.7g/L and 3.3g/L at 13 d of cultivation.

[Effects of companion fungus on several enzymatic activities of Grofola umbellata].

OBJECTIVE: To study the effect of companion fungus on several enzymatic activities of Grifola umbellata. METHOD: Chitinase, beta-1,3-glucanase, proteinase and extracellular enzymes of G. umbellata were measured during dual culturing with companion fungus. RESULT: Companion fungus could induce the increase of chitinase and beta-1, 3-glucanase activities of G. umbellata. noevident changeswere found in proteinase activity. When in liquid culture, the activities of extracellular enzymes in dual cultured filtrate were between of these of G. umbellata and companion fungus in monocultures. CONCLUSION: Sclerotia differentiation related materials supplied by mutual nutritional supplement between G. umbellata and companion fungus conduce to sclerotial formation of G. umbellata.