polysaccharide synthesis
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2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Qingqing Fang ◽  
Yu Feng ◽  
Alan McNally ◽  
Zhiyong Zong

AbstractCarbapenem-resistant Klebsiella pneumoniae (CRKP) has emerged as a severe global health challenge. We isolate and characterize two previously unidentified lytic phages, P24 and P39, with large burst sizes active against ST11 KL64, a major CRKP lineage. P24 and P39 represent species of the genera Przondovirus (Studiervirinae subfamily) and Webervirus (Drexlerviridae family), respectively. P24 and P39 together restrain CRKP growth to nearly 8 h. Phage-resistant mutants exhibit reduced capsule production and decreased virulence. Modifications in mshA and wcaJ encoding capsule polysaccharide synthesis mediate P24 resistance whilst mutations in epsJ encoding exopolysaccharide synthesis cause P39 resistance. We test P24 alone and together with P39 for decolonizing CRKP using mouse intestinal colonization models. Bacterial load shed decrease significantly in mice treated with P24 and P39. In conclusion, we report the characterization of two previously unidentified lytic phages against CRKP, revealing phage resistance mechanisms and demonstrating the potential of lytic phages for intestinal decolonization.


2021 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Tao Sun ◽  
Yixuan Zhang ◽  
Hao Jiang ◽  
Kai Yang ◽  
Shiyu Wang ◽  
...  

Naematelia aurantialba is a rare edible fungus with both nutritional and medicinal values and especially rich in bioactive polysaccharides. However, due to the lack of genomic information, researches on the mining of active compounds, artificial breeding and cultivation, genetics, and molecular biology are limited. To facilitate the medicinal and food applications of N. aurantialba, we sequenced and analyzed the whole genome of N. aurantialba for the first time. The 21-Mb genome contained 15 contigs, and a total of 5860 protein-coding genes were predicted. The genome sequence shows that 296 genes are related to polysaccharide synthesis, including 15 genes related to nucleoside-activated sugar synthesis and 11 genes related to glucan synthesis. The genome also contains genes and gene clusters for the synthesis of other active substances, including terpenoids, unsaturated fatty acids, and bioactive proteins. In addition, it was also found that N. aurantialba was more closely related to Naematelia encephala than to Tremella fuciformis. In short, this study provides a reference for molecular cognition of N. aurantialba and related researches.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Liang Ji ◽  
Shaohua Li ◽  
Cheng Chen ◽  
Haojie Jin ◽  
Haizhen Wu ◽  
...  

AbstractPorphyridium purpureum is a mesophilic, unicellular red alga rich in phycoerythrin, sulfate polysaccharides, and polyunsaturated fatty acids. Nitrogen deficiency inhibited the growth of P. purpureum and resulted in yellowing of the cells and thickening of the extracellular viscousness sheath. Under nitrogen stress, the contents of total lipids and exopolysaccharides in P. purpureum were increased by 65.2% and 188.0%, respectively. We demonstrate that the immediate response of P. purpureum to nitrogen deficiency is mediated by carbon flow to polysaccharide synthesis, while the synthesis of lipids is enhanced as a permanent energy storage substance at the later stage. Based on transcriptome annotation information, we elucidate the synthesis pathway of polysaccharides from P. purpureum from the perspective of glycosyl-donor interconversion, and demonstrate that the n-6 pathway is the main synthesis pathway of polyunsaturated fatty acids. This study not only provides a production strategy for polysaccharides and fatty acids by single-celled marine red algae P. purpureum, but also provides targets for further genetic modification.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qiang Zhang ◽  
Li Zhang ◽  
Yue Li ◽  
Ming Ye

Many clinically important drugs come directly or indirectly from higher plants. People are increasingly aware of the role of the human immune system in maintaining good health. Diseases related to physical dysfunction, such as vertigo, have attracted increasing attention from medical researchers and clinicians. In this paper, some compounds isolated and identified from medicinal fomes showed promising antivertigo properties. Medical images were used to classify and synthesize polysaccharides in the management of drug subpackages of Cladosporium intracellular polysaccharides. The scientific explanation of how these compounds work in animal and human systems is increasing exponentially. Studies have found that all of these compounds can enhance the innate and adaptive immune responses of the host and activate various immune cells that are important for maintaining homeostasis, such as host cells and chemical messengers, triggering complement and acute phase reactions. The antivertigo compounds derived from the intracellular polysaccharides of Phellinus mucronatus had an activity interference of 35% without drug subpackage. Although the antivertigo activity of many intracellular polysaccharides from Fovea xylostella can reach 86%, only a few of them have been proved to have antivertigo activity. In addition, they can be considered as multicytokine inducers that can induce the expression of various immune-regulatory cytokines and cytokine receptor genes. Lymphocytes that control antibody production and cell-mediated cytotoxicity are also stimulated.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11615
Author(s):  
Weida Lin ◽  
Huanwei Chen ◽  
Jianmei Wang ◽  
Yongli Zheng ◽  
Qiuwei Lu ◽  
...  

Background Cyclocarya paliurus (Batal.) Iljinskaja is a common endemic tree species and used as a Chinese medicine. The main active components in the leaves of this plant are polysaccharides. However, the temporal patterns of gene expression underlying the synthesis of polysaccharides in C. paliurus at different leaf developmental stages and its relationship with the polysaccharide content and antioxidant activities has not been reported to date. Methods RNA-seq was used to investigate the biosynthesis pathway of polysaccharides at the four developmental stages of C. paliurus leaves. The content and the antioxidant activities of polysaccharides were measured with typical biochemical methods and the identified correlations were statistically evaluated. Results Sixty-nine differentially expressed genes were found in the leaves during different developmental stages of C. paliurus. These are associated with glycosyltransferases and belong to 18 families. During different developmental stages of C. paliurus, the polysaccharide content first increased and then decreased, and the UDP-glucose 4-epimerase gene was found to be significantly positively correlated with the polysaccharide content. The clearance rates of DPPH radicals, superoxide anion radicals, hydroxyl radicals, and the reducing power of polysaccharides in the leaves of C. paliurus at different developmental stages showed a dose-dependent relationship with the concentration of polysaccharides. Conclusions The smallest fully expanded leaves are suitable for high-quality tea, and leaves with sizes below the largest fully expanded leaves are suitable for industrial production of polysaccharides.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinglong Su ◽  
Yingying Liu ◽  
Lu Han ◽  
Zhaojian Wang ◽  
Mengyang Cao ◽  
...  

AbstractPlatycodin D and platycoside E are two triterpenoid saponins in Platycodon grandiflorus, differing only by two glycosyl groups structurally. Studies have shown β-Glucosidase from bacteria can convert platycoside E to platycodin D, indicating the potential existence of similar enzymes in P. grandiflorus. An L9(34) orthogonal experiment was performed to establish a protocol for calli induction as follows: the optimal explant is stems with nodes and the optimum medium formula is MS + NAA 1.0 mg/L + 6-BA 0.5 mg/L to obtain callus for experimental use. The platycodin D, platycoside E and total polysaccharides content between callus and plant organs varied wildly. Platycodin D and total polysaccharide content of calli was found higher than that of leaves. While, platycoside E and total polysaccharide content of calli was found lower than that of leaves. Associating platycodin D and platycoside E content with the expression level of genes involved in triterpenoid saponin biosynthesis between calli and leaves, three contigs were screened as putative sequences of β-Glucosidase gene converting platycoside E to platycodin D. Besides, we inferred that some transcription factors can regulate the expression of key enzymes involved in triterpernoid saponins and polysaccharides biosynthesis pathway of P. grandiflorus. Totally, a candidate gene encoding enzyme involved in converting platycoside E to platycodin D, and putative genes involved in polysaccharide synthesis in P. grandiflorus had been identified. This study will help uncover the molecular mechanism of triterpenoid saponins biosynthesis in P. grandiflorus.


Author(s):  
Shuai Zhou ◽  
Xiaoyu Zhang ◽  
Fuying Ma ◽  
Shangxian Xie ◽  
Chuanhong Tang ◽  
...  

To systemically understand the biosynthetic pathways of bioactive substances, including triterpenoids and polysaccharides, in Ganoderma lucidum, the correlation between substrate degradation, carbohydrate and triterpenoid metabolism during growth was analyzed by combining changes in metabolite content and changes in related enzyme expression in G. lucidum over 5 growth phases. Changes in low-polarity triterpenoid content were correlated with changes in glucose and mannitol content in fruiting bodies. Additionally, changes in medium-polarity triterpenoid content were correlated with changes in the lignocellulose content of the substrate and with the glucose, trehalose and mannitol contents of fruiting bodies. Weighted gene coexpression network analysis (WGCNA) indicated that changes in trehalose and polyol content were related to carbohydrate catabolism and polysaccharide synthesis. Changes in triterpenoid content were related to expression of the carbohydrate catabolic enzymes, laccase, cellulase, hemicellulase, and polysaccharide synthase and to the expression of several cytochrome P450 monooxygenases (CYPs). It was concluded that the products of cellulose and hemicellulose degradation participate in polyol, trehalose and polysaccharide synthesis during initial fruiting body formation. These carbohydrates accumulate in the early phase of fruiting body formation and are utilized when the fruiting bodies mature and a large number of spores are ejected. An increase in carbohydrate metabolism provides additional precursors for the synthesis of triterpenoids. Importance Most studies of G. lucidum have focused on its medicinal function and on the mechanism of its activity, whereas the physiological metabolism and synthesis of bioactive substances during the growth of this species have been less studied. Therefore, theoretical guidance for cultivation methods to increase the production of bioactive compounds remains lacking. This study integrated changes in the lignocellulose, carbohydrate and triterpenoid contents of G. lucidum with enzyme expression from transcriptomics data using WGCNA. The findings helped us better understand the connections between substrate utilization and the synthesis of polysaccharides and triterpenoids during the cultivation cycle of G. lucidum. The results of WGCNA suggest that the synthesis of triterpenoids can be enhanced not only through regulating the expression of enzymes in the triterpenoid pathway, but also through regulating carbohydrate metabolism and substrate degradation. This study provides a potential approach and identifies enzymes that can be targeted to regulate lignocellulose degradation and accelerate the accumulation of bioactive substances by regulating substrate degradation in G. lucidum.


2021 ◽  
Vol 258 ◽  
pp. 117695
Author(s):  
Liting Zhao ◽  
Zhongbao Ma ◽  
Jian Yin ◽  
Guiyang Shi ◽  
Zhongyang Ding

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Ming Gong ◽  
Henan Zhang ◽  
Di Wu ◽  
Zhong Zhang ◽  
Jinsong Zhang ◽  
...  

Abstract Background Hericium erinaceus, a rare edible and medicine fungus, is widely used in the food and medical field. Polysaccharides from H. erinaceus are the main bioactive compound that exert high bioactive value in the medical and healthcare industries. Results The genome of H. erinaceus original strain HEA was reported 38.16 Mb, encoding 9780 predicted genes by single-molecule, real-time sequencing technology. The phylogenomic analysis showed that H. erinaceus had the closest evolutionary affinity with Dentipellis sp. The polysaccharide content in the fermented mycelia of mutated strains HEB and HEC, which obtained by ARTP mutagenesis in our previous study, was improved by 23.25 and 47.45%, and a new β-glucan fraction with molecular weight 1.056 × 106 Da was produced in HEC. Integrative analysis of transcriptome and proteomics showed the upregulation of the carbohydrate metabolism pathway modules in HEB and HEC might lead to the increased production of glucose-6P and promote the repeating units synthesis of polysaccharides. qPCR and PRM analysis confirmed that most of the co-enriched and differentially co-expressed genes involved in carbohydrate metabolism shared a similar expression trend with the transcriptome and proteome data in HEB and HEC. Heatmap analysis showed a noticeably decreased protein expression profile of the RAS-cAMP-PKA pathway in HEC with a highly increased 47.45% of polysaccharide content. The S phase progression blocking experiment further verified that the RAS-cAMP-PKA pathway’s dysfunction might promote high polysaccharide and β-glucan production in the mutant strain HEC. Conclusions The study revealed the primary mechanism of the increased polysaccharide synthesis induced by ARTP mutagenesis and explored the essential genes and pathways of polysaccharide synthesis.


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