High-efficiency production of plant-derived pigment dopaxanthin in Escherichia coli by combination engineering.

Background: Dopaxanthin is a natural pigment betaxanthins family member with the highest antioxidant and free radical scavenging activities. However, its relatively low content in plants limited the wide range of applications. Cost-efficient microbial production, therefore, showed an attractive alternative.

Functional Characterization and Molecular Basis of a Multi-Site Halogenase in Naphthacemycin Biosynthesis.

Halogenases are spurring a growing interest in the fields of biosynthesis and biocatalysis. Although various halogenases have been identified in numerous natural product biosynthetic pathways, the mechanisms for multiple halogenations and site-selectivity remain largely unclear. In this study, we biochemically characterized FasV, a flavin-dependent halogenase (FDH) that catalyzes five successive chlorinations in the biosynthesis of the naphthacene-containing aromatic polyketide naphthacemycin.

Soil viral-host interactions regulate microplastic-dependent carbon storage.

Microplastic is globally regarded as an important factor impacting biogeochemical cycles, yet our understanding of such influences is limited by the uncertainties of intricate microbial processes. By multiomics analysis, coupled with soil chemodiversity characterization and microbial carbon use efficiency (CUE), we investigated how microbial responses to microplastics impacted soil carbon cycling in a long-term field experiment. We showed that biodegradable microplastics promoted soil organic carbon accrual by an average of 2.

Improving Aerobic Digestion of Food Waste by Adding a Personalized Microbial Inoculum.

In the context of China's garbage classification policy, on-site aerobic food waste (FW) digestion is crucial for reducing transportation and disposal costs. The efficiency of this process is largely determined by the microbial community structure and its functions. Therefore, this study aimed to analyze the impact of a personalized microbial consortium (MCM) on the efficiency of aerobic FW digestion and to reveal the underlying mechanisms.

HcGr76 responds to fructose and chlorogenic acid and is involved in regulation of peptide expression in the midgut of Hyphantria cunea larvae.

Background: Sensing dietary components in the gut is important to ensure an appropriate hormonal response and metabolic regulation after food intake. The fall webworm, Hyphantria cunea, is a major invasive pest in China and has led to significant economic losses and ecosystem disruption. The larvae's broad host range and voracious appetite for leaves make H.

Rational engineering of Halomonas salifodinae to enhance hydroxyectoine production under lower-salt conditions.

Hydroxyectoine is an important compatible solute that holds potential for development into a high-value chemical with broad applications. However, the traditional high-salt fermentation for hydroxyectoine production presents challenges in treating the high-salt wastewater. Here, we report the rational engineering of Halomonas salifodinae to improve the bioproduction of hydroxyectoine under lower-salt conditions.

Prenylated indole diketopiperazine alkaloids as phosphatase inhibitors from the marine-derived fungus Talaromyces purpureogenus.

Six previously undescribed prenylated indole diketopiperazine alkaloids, talaromyines A-F (1-6), were isolated from the marine-derived fungus Talaromyces purpureogenus SCSIO 41517. Their structures including absolute configurations were elucidated on the basis of comprehensive spectroscopic data including NMR, HR-ESI-MS, and electronic circular dichroism calculations, together with chemical analysis of hydrolysates. Compounds 1-5 represent the first example of spirocyclic indole diketopiperazines biosynthesized from the condensation of L-tryptophan and L-alanine.

Caproicibacter sp. BJN0012, a potential new species isolated from cellar mud for caproic acid production from glucose.

Acids play a crucial role in enhancing the flavor of strong-aroma Baijiu, and among them, caproic acid holds significant importance in determining the flavor of the final product. However, the metabolic synthesis of caproic acid during the production process of Baijiu has received limited attention, resulting in fluctuations in caproic acid content among fermentation batches and generating production instability. Acid-producing bacteria found in the cellar mud are the primary microorganisms responsible for caproic acid synthesis, but there is a lack of research on the related microbial resources and their metabolic properties.

Microascones, Decahydrofluorene-Class Alkaloids from the Marine-Derived Fungus sp. SCSIO 41821.

Eight new decahydrofluorene-class alkaloids, microascones A and B ( and ), 2,3-epoxyphomapyrrolidone C (), 14,16-epiascomylactam B (), 24-hydroxyphomapyrrolidone A (), and microascones C-E (-), along with five known analogs (-) were isolated from the marine-derived fungus sp. SCSIO 41821. Compounds and have an unprecedented complex macrocyclic alkaloid skeleton with a 6/5/6/5/6/5/13 polycyclic system.

Angucyclinones with IDO and TDO inhibitory activities isolated from the actinomycetes Umezawaea beigongshangensis.

Four previously undescribed angucyclinones umezawaones A-D (1-4) were isolated from the liquid cultures of Umezawaea beigongshangensis. Their structures were determined by spectroscopic analyses, single crystal X-ray diffraction, quantum chemical C NMR and electronic circular dichroism calculations. All compounds displayed strong inhibitory activities against indoleamine 2,3-dioxygenase and tryptophan-2,3-dioxygenase in enzymatic assay, especially compound 2.

Alternaphenol B2, a new IDH1 inhibitor from the coral-derived fungus SCSIO SX7W11.

A new aromatic polyketide, alternaphenol B2 (), and four known compounds () were isolated from the coralderived fungus SCSIO SX7W11. Their structures were elucidated by high-resolution mass spectrometry, 1D and 2D NMR spectroscopy and comparison with reported literatures. Compounds and exhibited selective inhibitory activity against isocitrate dehydrogenase mutant R132H (IDH1m), with IC values of 41.

Unravelling Metabolic Heterogeneity of Chinese Baijiu Fermentation in Age-Gradient Vessels.

Fermentation vessels affect the characteristics of food fermentation; however, we lack an approach to identify the biomarkers indicating fermentation. In this study, we applied metabolomics and high-throughput sequencing analysis to reveal the dynamic of metabolites and microbial communities in age-gradient fermentation vessels for baijiu production. Furthermore, we identified 64 metabolites during fermentation, and 19 metabolites significantly varied among the three vessels ( < 0.

Microbial Communities and Correlation between Microbiota and Volatile Compounds in Fermentation Starters of Chinese Sweet Rice Wine from Different Regions.

Chinese sweet rice wines (CSRW) are traditional, regionally distinct alcoholic beverages that are generally brewed with glutinous rice and fermentation starters. This study aimed to characterize microbial communities and volatile compounds of CSRW starters and explore correlations between them. The major volatiles in starters include 1-heptanol, 1-octanol, 2-nonanol, phenylethyl alcohol, 2-nonanone, acetophenone, and benzaldehyde.

Multivariate modular metabolic engineering for enhanced L-methionine biosynthesis in Escherichia coli.

Background: L-Methionine is the only bulk amino acid that has not been industrially produced by the fermentation method. Due to highly complex and strictly regulated biosynthesis, the development of microbial strains for high-level L-methionine production has remained challenging in recent years.

Results: By strengthening the L-methionine terminal synthetic module via site-directed mutation of L-homoserine O-succinyltransferase (MetA) and overexpression of metA, metC, and yjeH, L-methionine production was increased to 1.

Characterization of the Positive Transcription Regulator PfaR for Improving Eicosapentaenoic Acid Production in Shewanella putrefaciens W3-18-1.

The biosynthetic pathway of eicosapentaenoic acid (EPA) has previously been reported in marine bacteria, while the regulatory mechanism remains poorly understood. In this study, a putative transcriptional regulator PfaR encoded adjacent to the PFA biosynthesis gene cluster () was computationally and experimentally characterized. Comparative analyses on the wild type (WT) strain, in-frame deletion, and overexpression mutants revealed that PfaR positively regulated EPA synthesis at low temperature.

Accurate and efficient protein sequence design through learning concise local environment of residues.

Motivation: Computational protein sequence design has been widely applied in rational protein engineering and increasing the design accuracy and efficiency is highly desired.

Results: Here, we present ProDESIGN-LE, an accurate and efficient approach to protein sequence design. ProDESIGN-LE adopts a concise but informative representation of the residue's local environment and trains a transformer to learn the correlation between local environment of residues and their amino acid types.

RNA-seq analysis revealing the immune response of Neocaridina denticulata sinensis gill to Vibrio parahaemolyticus infection.

Vibrio parahaemolyticus causes serious economic losses to the shrimp farming industry. There is still a lack of adequate understanding of the changes in the overall response of N. denticulata sinensis caused by V.

Carotane sesquiterpenoids A-G from the desert endophytic fungus sp. HM 166.

Seven undescribed carotane sesquiterpenoids named fusanoids A-G (1-7), along with one known analog (8) and two known sesterterpenes (9 and 10), were isolated from the fermentation broth of the desert endophytic fungi sp. HM166. The structures of the compounds, including their absolute configurations, were determined by spectroscopic data, single-crystal X-ray diffraction analysis, and ECD calculations.

Design of a genetically encoded biosensor to establish a high-throughput screening platform for L-cysteine overproduction.

Metabolic engineering seeks to rewire the metabolic network of cells for the efficient production of value-added compounds from renewable substrates. However, it remains challenging to evaluate and identify strains with the desired phenotype from the vast rational or random mutagenesis library. One effective approach to resolve this bottleneck is to design an efficient high-throughput screening (HTS) method to rapidly detect and analyze target candidates.

Discovery of glycosylated naphthacemycins and elucidation of the glycosylation.

Two glycosylated naphthacemycins (naphthacemycins D and D) were identified in Streptomyces sp. N12W1565. These two compounds not only showed antimicrobial potential against bacteria but also exhibited more aqueous solubility than naphthacemycins.

New protein tyrosine phosphatase inhibitors from fungus F07ZB1707.

Twelve new compounds, aspergorakhins A-L (1-12) coupled with one known xanthone leptosphaerin D (13), were isolated from the extract of soil-derived fungus F07ZB1707. Their structures were elucidated by spectroscopic data analysis including UV, IR, NMR, and HRESIMS. The absolute configurations of 5 and 8-11 were identified using ECD and OR calculations.

Structure-based discovery of a specific SHP2 inhibitor with enhanced blood-brain barrier penetration from PubChem database.

The thiophene [2,3-d]pyrimidine structure-like small molecules were discovered from structure-based virtual screening of 1 billion compounds. Base on enzyme activity assay results, a SHP2-specific molecule inhibitor Comp#2 with IC of 1.174 μM, 85-fold more selective for SHP2 than the highly related SHP1 (IC > 100 μM).

Aspergichromones A-E, Five Chromone Derivatives with Complicated Polycyclic Architecture from .

Five unprecedented chromone derivatives involving a 6/6/5/5/5/6 hexacyclic scaffold (, ), 6/6/5/6/6/6/6 heptacyclic scaffold (), and 6/6/6/5/5/6 hexacyclic scaffold (, ) were obtained from the fungus NCC0415. Their structures were identified using comprehensive spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Except for , the other compounds, especially the 6/6/6/5/5/6 hexacyclic derivatives ( and ), exhibited potent inosine-5'-monophosphate dehydrogenase (IMPDH) inhibitory activities.

Nitrite- and N2O-reducing bacteria respond differently to ecological factors in saline lakes.

The distribution of nitrite- and N2O-reducing bacteria is key to potential N2O emission from lakes. However, such information in highland saline lakes remains unknown. Here, we investigated the abundance and community composition of nitrite- and N2O-reducing bacteria in the sediments of six saline lakes on the Qing-Tibetan Plateau.