Enhanced Production of Ganoderic Acids and Cytotoxicity of Ganoderma lucidum Using Solid-Medium Culture

Submerged cultures of Ganoderma lucidum are used to produce fungal mycelium, which is used as a functional food and in the production of various triterpenoids, including ganoderic acids (GAs). Specific culture approaches that produce fungal mycelium with high levels of GAs and good biological activity are critical in the functional food industry. In this study, a solid-medium culture approach to producing mycelium was compared to the submerged culture system. Production of GAs, biomass, intracellular polysaccharides, and cytotoxicity of the cultured mycelium were compared as between solid and submerged culture. Growing G. lucidum strains on solid potato dextrose agar medium increased biomass, the production of ganoderic acid 24 (lanosta-7,9(11), 24-trien-3α-o1-26-oic acid), GAs, and total intracellular polysaccharides as compared to fungi grown in submerged culture. Triterpenoid-enriched methanol extracts of mycelium from solid-medium culture showed higher cytotoxicity than those from submerged culture. The IC(50) values of methanol extracts from solid-medium culture were 11.5, 8.6, and 9.9 times less than submerged culture on human lung cancer cells CH27, melanoma cells M21, and oral cancer cells HSC-3 respectively. The squalene synthase and lanosterol synthase coding genes had higher expression on the culture of solid potato dextrose medium. This is the first report that solid-medium culture is able to increase GA production significantly as compared to submerged culture and, in the process, produces much higher biological activity. This indicates that it may be possible to enhance the production of GAs by implementing mycelium culture on solid medium.     

Novel Mycelial Components,Ganoderic Acid Mg,Mh, Mi,Mj and Mk,from the Fungus Ganoderma lucidum

Five novel C₃₀ triterpenoids, ganoderic acids Mg (10), Mh (11), Mi (12), Mj (13) and Mk (14), were isolated from the mycelial mat of a G. lucidum strain, which produces C₂₇ lucidenic acids in the fruiting body. Their structures were determined by spectroscopic analysis and chemical conversion.     

破壁灵芝孢子粉诱导MCF-7细胞凋亡的机理研究

目的：研究破壁灵芝孢子粉对人乳腺癌细胞系MCF-7的诱导凋亡作用。方法：在体外设定不同浓度的孢子粉处理MCF-7细胞系的实验组,细胞培养24h后,用MTT法测定其细胞活力;碘化丙啶（vI）染色后流式细胞仪检测其凋亡情况;罗丹明123（Rodamine123）标记后于酶标仪530nIn处测定其荧光强度值以检测线粒体膜电位情况。结果：与对照组相比,随孢子粉浓度的上升,MCF-7细胞活力和增殖呈剂量依赖型的下降;流式细胞仪检测PI染色显示,各处理组的MCF-7细胞凋亡率随作用浓度的上升而增强,最高浓度组尤为明显;在高浓度组,罗丹明123荧光强度明显降低。这些结果表明孢子粉能抑制MCF-7细胞的活力扣增殖;诱导其凋亡;罗丹明荧光强度的减少,说明MCF-7线粒体膜电位有倒塌扣去极化的情况发生,提示MCF-7细胞的凋亡与线粒体有关。结论：破壁灵芝孢子粉可明显促进MCF-7细胞的凋亡。     

灵芝肽诱导人肝癌HepG2细胞凋亡的研究

研究了灵芝肽(GLP)在体外对人肝癌HepG2细胞凋亡的影响,并初步探讨了其作用机制。结果显示,透射电镜下可见细胞染色质浓缩、聚集于核边缘成块状,形成典型的凋亡小体;GLP使HepG2细胞阻滞于G0/G1期,随着GLP浓度升高,其G0/G1期的细胞比例随之增加;同时细胞的早期、晚期和总的凋亡率亦均随之增加,存在剂量-效应关系;Western blotting检测结果显示,抑制凋亡基因bcl-2和survivin表达下调,而促凋亡基因p53表达上调,并且都存在剂量依赖性;细胞凋亡的关键蛋白酶caspase-3被激活,并且caspase-3酶活性与GLP浓度亦有剂量依赖性。提示GLP体外可诱导人肝癌HepG2细胞凋亡,其作用机制可能与bcl-2和survivin表达下调、p53表达上调及Caspase-3被激活有关。     

灵芝深层发酵生产四环三萜酸的研究

从灵芝深层发酵产物中分离得到三种四环三萜酸,命名为灵芝酸Ｍ１,Ｍ２,Ｍ３,在２５Ｌ发酵罐上研究了发酵条件对灵芝酸产量的影响,以及灵芝酸的代谢形成特征。结果表明最适发酵条件是：温度３０℃;通风量１：０．７５ｖ／ｖ／ｍ;搅拌转速１８０ｒ／ｍｉｎ;发酵时间８０ｈ,此时灵芝酸的最高产量是０．３６ｇ／Ｌ发酵液。抑菌实验表明上述灵芝酸能够抑制大肠杆菌,产气杆菌、肠炎杆菌、金黄色葡萄球菌和枯草芽孢杆菌的生长。     

Production of ganoderic acid by Ganoderma lucidum RCKB-2010 and its therapeutic potential

The newly isolated basidiomycetous fungus, identified as Ganoderma lucidum RCKB-2010 was tested for production of ganoderic acid (GA) under submerged fermentation conditions. Production of GA under liquid static cultivation condition was found to be 2,755.88 mg L^?1 on the 25th day of incubation, whereas under shaking cultivation conditions the maximum production of GA was observed to be 373.75 mg L^?1. ¹H NMR analysis revealed clearly that the fungal extracts possessed a lanostane skeleton, confirming the presence of GA. Interestingly, GA was found to have potential to inhibit the proliferation of HeLa cells and U87 human glioma cells in a dose dependent manner. In addition, GA was also found to possess antibacterial activity, exhibiting a minimal inhibitory concentration of 0.25 mg mL^?1 against standard strains of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Staphylococcus epidermidis. GA produced in the present study holds potential as a potent anticancer agent.     

A Novel Muconic Acid Biosynthesis Approach by Shunting Tryptophan Biosynthesis via Anthranilate

Muconic acid is the synthetic precursor of adipic acid, and the latter is an important platform chemical that can be used for the production of nylon-6,6 and polyurethane. Currently, the production of adipic acid relies mainly on chemical processes utilizing petrochemicals, such as benzene, which are generally considered environmentally unfriendly and nonrenewable, as starting materials. Microbial synthesis from renewable carbon sources provides a promising alternative under the circumstance of petroleum depletion and environment deterioration. Here we devised a novel artificial pathway in Escherichia coli for the biosynthesis of muconic acid, in which anthranilate, the first intermediate in the tryptophan biosynthetic branch, was converted to catechol and muconic acid by anthranilate 1,2-dioxygenase (ADO) and catechol 1,2-dioxygenase (CDO), sequentially and respectively. First, screening for efficient ADO and CDO from different microbial species enabled the production of gram-per-liter level muconic acid from supplemented anthranilate in 5 h. To further achieve the biosynthesis of muconic acid from simple carbon sources, anthranilate overproducers were constructed by overexpressing the key enzymes in the shikimate pathway and blocking tryptophan biosynthesis. In addition, we found that introduction of a strengthened glutamine regeneration system by overexpressing glutamine synthase significantly improved anthranilate production. Finally, the engineered E. coli strain carrying the full pathway produced 389.96 ± 12.46 mg/liter muconic acid from simple carbon sources in shake flask experiments, a result which demonstrates scale-up potential for microbial production of muconic acid.     

A Novel Approach to Decrease Sialic Acid Expression in Cells by a C-3-modified N-Acetylmannosamine

Due to its position at the outermost of glycans, sialic acid is involved in a myriad of physiological and pathophysiological cell functions such as host-pathogen interactions, immune regulation, and tumor evasion. Inhibitors of cell surface sialylation could be a useful tool in cancer, immune, antibiotic, or antiviral therapy. In this work, four different C-3 modified N-acetylmannosamine analogs were tested as potential inhibitors of cell surface sialylation. Peracetylated 2-acetylamino-2-deoxy-3-O-methyl-d-mannose decreases cell surface sialylation in Jurkat cells in a dose-dependent manner up to 80%, quantified by flow cytometry and enzyme-linked lectin assays. High-performance liquid chromatography experiments revealed that not only the concentration of membrane bound but also of cytosolic sialic acid is reduced in treated cells. We have strong evidence that the observed reduction of sialic acid expression in cells is caused by the inhibition of the bifunctional enzyme UDP-GlcNAc-2-epimerase/ManNAc kinase. 2-Acetylamino-2-deoxy-3-O-methyl-d-mannose inhibits the human ManNAc kinase domain of the UDP-GlcNAc-2-epimerase/ManNAc kinase. Binding kinetics of the inhibitor and human N-acetylmannosamine kinase were evaluated using surface plasmon resonance. Specificity studies with human N-acetylglucosamine kinase and hexokinase IV indicated a high specificity of 2-acetylamino-2-deoxy-3-O-methyl-d-mannose for MNK. This substance represents a novel class of inhibitors of sialic acid expression in cells, targeting the key enzyme of sialic acid de novo biosynthesis.     

Enhancement of Ganoderic Acid Accumulation by Overexpression of an N-Terminally Truncated 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Gene in the Basidiomycete Ganoderma lucidum

Ganoderic acids produced by Ganoderma lucidum, a well-known traditional Chinese medicinal mushroom, exhibit antitumor and antimetastasis activities. Genetic modification of G. lucidum is difficult but critical for the enhancement of cellular accumulation of ganoderic acids. In this study, a homologous genetic transformation system for G. lucidum was developed for the first time using mutated sdhB, encoding the iron-sulfur protein subunit of succinate dehydrogenase, as a selection marker. The truncated G. lucidum gene encoding the catalytic domain of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) was overexpressed by using the Agrobacterium tumefaciens-mediated transformation system. The results showed that the mutated sdhB successfully conferred carboxin resistance upon transformation. Most of the integrated transfer DNA (T-DNA) appeared as a single copy in the genome. Moreover, deregulated constitutive overexpression of the HMGR gene led to a 2-fold increase in ganoderic acid content. It also increased the accumulation of intermediates (squalene and lanosterol) and the upregulation of downstream genes such as those of farnesyl pyrophosphate synthase, squalene synthase, and lanosterol synthase. This study demonstrates that transgenic basidiomycete G. lucidum is a promising system to achieve metabolic engineering of the ganoderic acid pathway.     

Novel Method of Lactic Acid Production by Electrodialysis Fermentation

In lactic acid fermentation by Lactobacillus delbrueckii, the produced lactic acid affected the lactic acid productivity. Therefore, for the purpose of alleviating this inhibitory effect, an electrodialysis fermentation method which can continuously remove produced lactic acid from the fermentation broth was applied to this fermentation process. As a result, the continuation of fermentation activity was obtained, and the productivity was three times higher than in non-pH-controlled fermentation. In electrodialysis fermentation, the amount of produced lactic acid was 82.2 g/liter, which was about 5.5 times greater than that produced in non-pH-controlled fermentation. It was concluded that these good results were obtained on account of alleviating the lactic acid inhibitory effect by electrodialysis fermentation. However, the fouling of anion-exchange membranes by cells was observed in electrodialysis fermentation.     

A novel membrane-surface liquid co-culture to improve the production of laccase from Ganoderma lucidum

In this work, a laccase producer, Ganoderma lucidum, was separated and identified according to its morphological characteristics and phylogenetic data. A 4000 U/l and 8500 U/l of laccase activity was obtained in 500 ml flask by submerged culture and biomembrane-surface liquid culture (BSLC), respectively. Furthermore, the novel biomembrane-surface liquid co-culture (BSLCc) was developed by adding Saccharomyces cerevisiae to reactor in order to shorten the fermentation period and improve laccase production. Laccase activity obtained by BSLCc, 23 000 U/l, is 5.8 and 2.7 times of that obtained by submerged culture and BSLC, respectively. In addition, laccase production by BSLCc was successfully scaled-up to 100 l reactor, and 38 000 U/l of laccase activity was obtained on day 8. The mechanism of overproducing laccase by BSLCc was investigated by metabolism pathway analysis of glucose. The results show glucose limitation in fermentation broth induces the secretion of laccase. The addition of S. cerevisiae, on one hand, leads to an earlier occurrence of glucose limitation state, and thus shortens the fermentation time; on the other hand, it also results in the appearance of a series of metabolites of the yeast including organic acids, ethanol, glycerol and so forth in fermentation broth, and both polyacrylamide gel electrophoresis analysis and enzyme activity detection of laccase show that these metabolites contribute to the improvement of laccase activity.     

A Novel Codoping Approach for Enhancing the Performance of LiFePO4 Cathodes

By combining experimental and theoretical studies, we have demonstrated that donor‐acceptor charge‐compensating codoping is a promising approach to significantly enhance the rate performance of LiFePO₄ cathodes. Our density‐functional theory calculation predicts that codoping with Si on the P site and F on the O site modifies the nature of the conduction band edge of LiFePO₄ from localized Fe 3d derived states to more delocalized F s and cation s derived states. This effect, thus changes the carrier transport from a poloron‐like to a band‐like mechanism, and consequently leads to significant improvement in the electrical conductivity of LiFePO₄. Most importantly, our comparative doping experiments show that the electrical conductivity of Si _P ‐F_O codoped LiFePO₄ exhibits at least 2 to 3 orders of magnitude increase in electrical conductivity as compared to that of un‐doped LiFePO₄. Because of the dramatic improvement of electrical conductivity, the optimal Si‐F codoped LiFePO₄ shows both a much higher rate‐capability than un‐doped LiFePO₄ or LiFePO₄ solely doped with either Si or F. Furthermore, we also believe that the charge‐compensating codoping approach may be employed to improve the performance of other cathode materials suffering from inferior electrical conductivities due to localized conduction band states.     

Ganoderic Acid A Attenuates LPS-Induced Neuroinflammation in BV2 Microglia by Activating Farnesoid X Receptor

Neurochemical Research - Neuroinflammation plays an important role in the onset and progression of neurodegenerative diseases. Microglia-mediated neuroinflammation have been proved to be the main...     

Purification and characterization of a novel proteinase A inhibitor from Ganoderma lucidum by submerged fermentation

A novel proteinase A inhibitor was purified from Ganoderma lucidum. The purification was carried out by ethanol precipitation (50–80%), ACA44 gel filtration and Source 30Q anion exchange, respectively. The molecular mass of the inhibitor was 38 kDa as estimated via SDS-PAGE and gel filtration. Its carbohydrate content was up to 70%. β-Elimination revealed that the linkage between the glycan and the core protein backbone might be O-linkage. This inhibitor showed a remarkable heat stability. By investigating the interaction between this inhibitor and a variety of proteinases, it is indicated that the inhibitor was more specific against yeast proteinase A than other proteinases. The dissociation constants (Ki) and concentration required for 50% inhibition (IC₅₀) for proteinase A were 2.7 × 10⁻⁶ M and 0.16 mg/ml, respectively.     

ROS Production and Apoptosis Induction by Formation of Gts1p-Mediated Protein Aggregates

GTS1 of Saccharomyces cerevisiae is a pleiotropic gene. Its induction leads to a variety of biological phenomena represented by cell aggregation. The C-terminal polyglutamine sequence in Gts1p is indispensable for its pleiotropy and nuclear localization. This sequence is often observed in polyglutamine diseases, such as Huntington disease, and is believed to induce protein aggregation, leading to cell death. In this study, protein aggregates were formed in a polyglutamine-dependent manner in cells inducing GTS1, and heat-shock protein family, translation elongation factor, and mitochondrial proteins were trapped in Gts1p-mediated protein aggregates. Moreover, the polyglutamine sequence of Gts1p was indispensable to the induction of reactive oxygen species (ROS) production and apoptosis. Deletion of the genes encoding Por1p and Yhb1p altered the profiles of ROS production and apoptosis caused by GTS1 induction, suggesting that the trapping of these proteins in Gts1p-mediated protein aggregates inhibits the intrinsic functions of these proteins.     

Targeted Anticancer Drug Delivery Using Chitosan,Carbon Quantum Dots,and Aptamers to Deliver Ganoderic Acid and 5-Fluorouracil

Breast cancer is a malignancy that affects mostly females and is among the most lethal types of cancer. The ligand-functionalized nanoparticles used in the nano-drug delivery system offer enormous potential for cancer treatments. This work devised a promising approach to increase drug loading efficacy and produce sustained release of 5-fluorouracil (5-FU) and Ganoderic acid (GA) as model drugs for breast cancer. Chitosan, aptamer, and carbon quantum dot (CS/Apt/COQ) hydrogels were initially synthesized as a pH-sensitive and biocompatible delivery system. Then, CS/Apt/COQ NPs loaded with 5-FU-GA were made using the W/O/W emulsification method. FT-IR, XRD, DLS, zeta potentiometer, and SEM were used to analyze NP's chemical structure, particle size, and shape. Cell viability was measured using MTT assays in vitro using the MCF-7 cell lines. Real-time PCR measured cell apoptotic gene expression. XRD and FT-IR investigations validated nanocarrier production and revealed their crystalline structure and molecular interactions. DLS showed that nanocarriers include NPs with an average size of 250.6 nm and PDI of 0.057. SEM showed their spherical form, and zeta potential studies showed an average surface charge of +37.8 mV. pH 5.4 had a highly effective and prolonged drug release profile, releasing virtually all 5-FU and GA in 48 h. Entrapment efficiency percentages for 5-FU and GA were 84.7±5.2 and 80.2 %±2.3, respectively. The 5-FU-GA-CS-CQD-Apt group induced the highest cell death, with just 57.9 % of the MCF-7 cells surviving following treatment. 5-FU and GA in CS-CQD-Apt enhanced apoptotic induction by flow cytometry. 5-FU-GA-CS-CQD-Apt also elevated Caspase 9 and downregulated Bcl2. Accordingly, the produced NPs may serve as pH-sensitive nano vehicles for the controlled release of 5-FU and GA in treating breast cancer.     

A Novel Approach to Quantify Time Series Differences of Gait Data Using Attractor Attributes

In this paper we introduce a new method to expressly use live/corporeal data in quantifying differences of time series data with an underlying limit cycle attractor; and apply it using an example of gait data. Our intention is to identify gait pattern differences between diverse situations and classify them on group and individual subject levels. First we approximated the limit cycle attractors, from which three measures were calculated: δM amounts to the difference between two attractors (a measure for the differences of two movements), δD computes the difference between the two associated deviations of the state vector away from the attractor (a measure for the change in movement variation), and δF, a combination of the previous two, is an index of the change. As an application we quantified these measures for walking on a treadmill under three different conditions: normal walking, dual task walking, and walking with additional weights at the ankle. The new method was able to successfully differentiate between the three walking conditions. Day to day repeatability, studied with repeated trials approximately one week apart, indicated excellent reliability for δM (ICC_ave > 0.73 with no differences across days; p > 0.05) and good reliability for δD (ICC_ave  =  0.414 to 0.610 with no differences across days; p > 0.05). Based on the ability to detect differences in varying gait conditions and the good repeatability of the measures across days, the new method is recommended as an alternative to expensive and time consuming techniques of gait classification assessment. In particular, the new method is an easy to use diagnostic tool to quantify clinical changes in neurological patients.