The Airway Microbiota of Non-Small-Cell Lung Cancer Patients and Its Relationship to Tumor Stage and EGFR Mutation

Background: Accumulating studies have suggested the airway microbiota of lung cancer was significantly different from healthy controls. However, little was known about the relationship between airway microbiota and important clinical parameters of lung cancer. In this study, we aimed to explore the association between sputum microbiota and lung cancer stage, lymph node metastasis, intrathoracic metastasis, and Epidermal growth factor receptor (EGFR) gene mutation. Methods: The microbiota of sputum samples from 85 newly diagnosed NSCLC patients were sequenced via 16S rRNA sequencing with V3-V4 region. Sequencing reads were filtered using QIIME2 and clustered against UPARSE. Results: The α diversity and β diversity was significantly different between patients in stage I to II (early stage, ES) and patients in stage III to IV (advanced stage, AS). Lefse identified that genera Granulicatella and Actinobacillus were significantly enriched in ES, and genus Actinomyces were significantly enriched in AS. PICRUSt2 identified NAD salvage pathway was significantly enriched in AS, which was positively associated with Granulicatella. Patients with intrathoracic metastasis were associated with increased genus Peptostreptococcus and incomplete reductive TCA cycle, which was associated with increased Peptostreptococcus. Genera Parvimonas, Pseudomona and L-valine biosynthesis were positively associated with lymph node metastasis. L-valine biosynthesis was related with increased Pseudomona. Finally, genus Parvimonas were significantly upregulated in adenocarcinoma patients with EGFR mutation. Conclusion: Taxonomy structure differed between different lung cancer stage. The tumor stage, intrathoracic metastasis, lymph node metastasis, and EGFR mutation were associated with alteration of specific airway genera and metabolic function of sputum microbiota.

Engineering of microbial cells for L-valine production: challenges and opportunities

L-valine is an essential amino acid that has wide and expanding applications with a suspected growing market demand. Its applicability ranges from animal feed additive, ingredient in cosmetic and special nutrients in pharmaceutical and agriculture fields. Currently, fermentation with the aid of model organisms, is a major method for the production of L-valine. However, achieving the optimal production has often been limited because of the metabolic imbalance in recombinant strains. In this review, the constrains in L-valine biosynthesis are discussed first. Then, we summarize the current advances in engineering of microbial cell factories that have been developed to address and overcome major challenges in the L-valine production process. Future prospects for enhancing the current L-valine production strategies are also discussed.

The Airway Microbiota of Non-small-cell Lung Cancer Patients and its Relationship to Tumor Stage and EGFR Gene Mutation

Background: Accumulating studies have suggested the airway microbiota of lung cancer was significantly different from healthy controls. However, little was known about the relationship between airway microbiota and important clinical parameters of lung cancer. In this study, we aimed to explore the association between sputum microbiota and lung cancer stage, lymph node metastasis, intrathoracic metastasis, and Epidermal growth factor receptor (EGFR) gene mutation. Methods: The microbiota of sputum samples from 85 newly diagnosed NSCLC patients were sequenced via 16S rRNA sequencing with V3-V4 region. Sequencing reads were filtered using QIIME2 and clustered against UPARSE. Results: The α diversity and β diversity was significantly different between patients in stage I to II (early stage, ES) and patients in stage III to IV (advanced stage, AS). Lefse identified that genera Granulicatella and Actinobacillus were significantly enriched in ES, and genus Actinomyces were significantly enriched in AS. PICRUSt2 identified NAD salvage pathway was significantly enriched in AS, which was positively associated with Granulicatella. Patients with intrathoracic metastasis were associated with increased genus Peptostreptococcus and incomplete reductive TCA cycle. Enrichment of TCA cycle was associated with increased Peptostreptococcus. Genera Parvimonas, Pseudomona and L-valine biosynthesis were positively associated with lymph node metastasis. L-valine biosynthesis was related with increased Pseudomona. Finally, genus Parvimonas were significantly upregulated in adenocarcinoma patients with EGFR mutation. Conclusion: In conclusion, the taxonomy structure differed between different lung cancer stage. The tumor stage, intrathoracic 1 metastasis, lymph node metastasis, and EGFR mutation were associated with alteration of specific airway genera and metabolic function of sputum microbiota.

USAGE OF TRANSCRIPTIONAL REGULATOR LRP BASED BIOSENSOR FOR RESEARCH OF VALINE BIOSYNTHESIS PATHWAYS IN CORYNEBACTERIUM GLUTAMICUM CELLS

The biosensor construction based on Lrp gene was obtained, what contains a fluorescence protein gene under control of BrnFE gene promotor. It was displayed that the fluorescence of Corynebacterium glutamicum cells carrying the biosensor correlates with the production of valine, and with its help it is possible to study the biosynthesis of valine.

Integrated Metabolome and Transcriptome Analysis Provide Insights into the Effects of Grafting on Fruit Flavor of Cucumber with Different Rootstocks

Rootstocks frequently exert detrimental effects on the fruit quality of grafted cucumber (Cucumis sativus L.) plants. To understand and ultimately correct this deficiency, a transcriptomic and metabolomic comparative analysis was performed among cucumber fruits from non-grafted plants (NG), and fruits from plants grafted onto different rootstocks of No.96 and No.45 (Cucurbita moschata. Duch), known to confer a different aroma and taste. We found remarkable changes in the primary metabolites of sugars, organic acids, amino acids, and alcohols in the fruit of the grafted cucumber plants with different rootstocks, compared to the non-grafted ones, especially No.45. We identified 140, 131, and 244 differentially expressed genes (DEGs) in the comparisons of GNo.96 vs. NG, GNo.45 vs. NG, and GNo.45 vs. GNo.96. The identified DEGs have functions involved in many metabolic processes, such as starch and sucrose metabolism; the biosynthesis of diterpenoid, carotenoid, and zeatin compounds; and plant hormone signal transduction. Members of the HSF, AP2/ERF-ERF, HB-HD-ZIP, and MYB transcription factor families were triggered in the grafted cucumbers, especially in the cucumber grafted on No.96. Based on a correlation analysis of the relationships between the metabolites and genes, we screened 10 candidate genes likely to be involved in sugar metabolism (Fructose-6-phosphate and trehalose), linoleic acid, and amino-acid (isoleucine, proline, and valine) biosynthesis in grafted cucumbers, and then confirmed the gene expression patterns of these genes by qRT-PCR. The levels of TPS15 (Csa3G040850) were remarkably increased in cucumber fruit with No.96 rootstock compared with No.45, suggesting changes in the volatile chemical production. Together, the results of this study improve our understanding of flavor changes in grafted cucumbers, and identify the candidate genes involved in this process.

Improvement of the Redox Balance Increases l-Valine Production by Corynebacterium glutamicum under Oxygen Deprivation Conditions

ABSTRACTProduction ofl-valine under oxygen deprivation conditions byCorynebacterium glutamicumlacking the lactate dehydrogenase geneldhAand overexpressing thel-valine biosynthesis genesilvBNCDEwas repressed. This was attributed to imbalanced cofactor production and consumption in the overalll-valine synthesis pathway: two moles of NADH was generated and two moles of NADPH was consumed per mole ofl-valine produced from one mole of glucose. In order to solve this cofactor imbalance, the coenzyme requirement forl-valine synthesis was converted from NADPH to NADH via modification of acetohydroxy acid isomeroreductase encoded byilvCand introduction ofLysinibacillus sphaericusleucine dehydrogenase in place of endogenous transaminase B, encoded byilvE. The intracellular NADH/NAD+ratio significantly decreased, and glucose consumption andl-valine production drastically improved. Moreover,l-valine yield increased and succinate formation decreased concomitantly with the decreased intracellular redox state. These observations suggest that the intracellular NADH/NAD+ratio, i.e., reoxidation of NADH, is the primary rate-limiting factor forl-valine production under oxygen deprivation conditions. Thel-valine productivity and yield were even better and by-products derived from pyruvate further decreased as a result of a feedback resistance-inducing mutation in the acetohydroxy acid synthase encoded byilvBN. The resultant strain produced 1,470 mMl-valine after 24 h with a yield of 0.63 mol mol of glucose−1, and thel-valine productivity reached 1,940 mM after 48 h.