Chromatographic and mass spectroscopic guided discovery of peptaibiotics and their bioactivity.

Peptaibiotics are linear or cyclic peptide antibiotics characterized by the non-proteinogenic amino acid, alpha-aminoisobutyric acid. They exhibit a wide range of bioactivity against various pathogens. This report presents a comprehensive review of analytical methods for cultivation, production, isolation, screening, purification, and characterization of peptaibiotics, along with their bioactivity.

The divergence of DHN-derived melanin pathways in Metarhizium robertsii.

The important role of dihydroxynaphthalene-(DHN) melanin in enhancing fungal stress resistance and its importance in fungal development and pathogenicity are well-established. This melanin also aids biocontrol fungi in surviving in the environment and effectively infecting insects. However, the biosynthetic origin of melanin in the biocontrol agents, Metarhizium spp.

Re-Engineering Fungal Nonribosomal Peptide Synthetases by Module Dissection and Duplicated Thiolation Domains.

Unnatural product (uNP) nonribosomal peptides promise to be a valuable source of pharmacophores for drug discovery. However, the extremely large size and complexity of the nonribosomal peptide synthetase (NRPS) enzymes pose formidable challenges to the production of such uNPs by combinatorial biosynthesis and synthetic biology. Here we report a new NRPS dissection strategy that facilitates the engineering and heterologous production of these NRPSs.

Isolation, Characterization, and Bioherbicidal Potential of the 16-Residue Peptaibols from sp. XJ1056.

Eco-friendly bioherbicides are urgently needed for managing the problematic weed . A mass spectrometry- and bioassay-guided screening approach was employed to identify phytotoxic secondary metabolites from fungi for the development of such bioherbicides. This effort led to the discovery of six phytotoxic 16-residue peptaibols, including five new compounds (-) and a known congener (), from sp.

A novel nucleic acid linker for multi-gene expression enhances plant and animal synthetic biology.

The production of compact vectors for gene stacking is hindered by a lack of effective linkers. Here, we report that a 26-nt nucleic acid linker, NAL1, from the fungus Glarea lozoyensis and its truncated derivatives could connect two genes as a bicistron, enabling independent translation in a maize protoplast transient expression system and human 293 T cells. The optimized 9-nt NAL10 linker was then used to connect four genes driven by a bidirectional promoter; this combination was successfully used to reconstruct the astaxanthin biosynthesis pathway in transgenic maize.

Onygenaleosides A-F, 6/5 Bicyclic Ring Skeleton Triterpene Glycosides with Insecticidal Activity from sp. YX1425.

Six new squalene derived polyether glycosides, onygenaleosides A-F (-), that possess a 6/5 bicyclic fused ring skeleton were isolated from the cultures of sp. YX1425, along with two known analogues ( and ). The planar structures of the new compounds were elucidated based on analysis of NMR and MS spectroscopy data, and the absolute configuration of was determined by the advanced Mosher method and quantum chemical calculations.

De novo biosynthesis of anticarcinogenic icariin in engineered yeast.

Icariin (ICA) has wide applications in nutraceuticals and medicine with strong anticancer activities. However, the structural complexity and low abundance in plants of ICA lead to the unsustainable and high-cost supply from chemical synthesis and plant extraction. Here, the whole biosynthesis pathway of ICA was elucidated, then was constructed in Saccharomyces cerevisiae, including a 13-step heterologous ICA pathway from eleven kinds of plants as well as deletions or overexpression of ten yeast endogenous genes.

Mass Spectrometry-Guided Discovery of Multi--Methylated Cyclodecapeptides Auyuittuqamides E-H from sp. QL0466.

Mass spectrometry-based dereplication and prioritization led to the discovery of four multi--methylated cyclodecapeptides, auyuittuqamides E-H (-), from a soil-derived sp. The planar structures of these compounds were elucidated based on analysis of HRESIMS and NMR data. Absolute configurations of the chiral amino acid residues were assigned by a combination of the advanced Marfey's method, chiral-phase LC-MS analysis, and -based configuration analysis, revealing that - contain both d- and l-isomers of -methylleucine (MeLeu).

Characterization of a salt-resistant isocitrate lyase gene from mangrove wetland using shotgun metagenomic sequencing.

Isocitrate lyase (ICL), as the key enzyme in the glyoxylate metabolic pathway, plays an important role in metabolic adaptation to environmental changes. In this study, metagenomic DNA from the soil and water microorganism collected from the Dongzhai Harbor Mangroves (DHM) reserve, in Haikou City, China, was high-throughput sequenced using an Illumina HiSeq 4000 platform. The icl121 gene, encoding an ICL with the highly conserved catalytic pattern IENQVSDEKQCGHQD was identified.

Engineering the biosynthesis of fungal nonribosomal peptides.

Covering: 2011 up to the end of 2021.Fungal nonribosomal peptides (NRPs) and the related polyketide-nonribosomal peptide hybrid products (PK-NRPs) are a prolific source of bioactive compounds, some of which have been developed into essential drugs. The synthesis of these complex natural products (NPs) utilizes nonribosomal peptide synthetases (NRPSs), multidomain megaenzymes that assemble specific peptide products by sequential condensation of amino acids and amino acid-like substances, independent of the ribosome.

Halovirs I-K, antibacterial and cytotoxic lipopeptaibols from the plant pathogenic fungus Paramyrothecium roridum NRRL 2183.

Three new lipopeptaibols, halovirs I-K (1-3), were isolated from the solid culture of the phytopathogenic fungus Paramyrothecium roridum NRRL 2183. Their planar structures, which consist of a hexapeptide backbone and acyl substitutions at the N- and C-termini, were elucidated by comprehensive analysis of the 1D and 2D NMR spectroscopic data along with the detailed interpretation of the MS/MS fragmentation pattern. Absolute configurations of the amino acid/1,2-amino alcohol residues were determined using the advanced Marfey's method.

Combined assembly of long and short sequencing reads improve the efficiency of exploring the soil metagenome.

Background: Advances in DNA sequencing technologies have transformed our capacity to perform life science research, decipher the dynamics of complex soil microbial communities and exploit them for plant disease management. However, soil is a complex conglomerate, which makes functional metagenomics studies very challenging.

Results: Metagenomes were assembled by long-read (PacBio, PB), short-read (Illumina, IL), and mixture of PB and IL (PI) sequencing of soil DNA samples were compared.

[Advances in engineering non-ribosomal peptide synthetase].

Non-ribosomal peptide synthetases catalyze the biosynthesis of structurally and functionally diverse non-ribosomal peptide natural products, which have broad applications in pharmaceutical, agricultural, and industrial sectors. Engineered non-ribosomal peptide synthetases can be used to produce novel non-ribosomal peptides through combinatorial biosynthesis. This conforms to the concept of green chemistry, thus attracts increasing attention across the world.

Combinatorial Biosynthesis of Sulfated Benzenediol Lactones with a Phenolic Sulfotransferase from Fusarium graminearum PH-1.

Total biosynthesis or whole-cell biocatalytic production of sulfated small molecules relies on the discovery and implementation of appropriate sulfotransferase enzymes. Although fungi are prominent biocatalysts and have been used to sulfate drug-like phenolics, no gene encoding a sulfotransferase enzyme has been functionally characterized from these organisms. Here, we identify a phenolic sulfotransferase, FgSULT1, by genome mining from the plant-pathogenic fungus PH-1.

Intrinsic and Extrinsic Programming of Product Chain Length and Release Mode in Fungal Collaborating Iterative Polyketide Synthases.

Combinatorial biosynthesis with fungal polyketide synthases (PKSs) promises to produce unprecedented bioactive "unnatural" natural products (uNPs) for drug discovery. Genome mining of the dothideomycete uncovered a collaborating highly reducing PKS (hrPKS)-nonreducing PKS (nrPKS) pair. These enzymes produce trace amounts of rare S-type benzenediol macrolactone congeners with a phenylacetate core in a heterologous host.

Strepimidazoles A-G from the Plant Endophytic sp. PKU-EA00015 with Inhibitory Activities against a Plant Pathogenic Fungus.

Seven new 4-acyl-2-aminoimidazoles, designated strepimidazoles A-G (-), were discovered from the endophytic sp. PKU-EA00015 isolated from Bunge, whose dry root "Danshen" is one of the most widely used traditional Chinese medicines. The resonance signals of the 2-aminoimidazole moiety in - were absent in the NMR spectra due to tautomerization, and the structures of - were identified after preparation of their acetylation products -, respectively.

Herbicidal efficacy of harzianums produced by the biofertilizer fungus, Trichoderma brevicompactum.

Herbicides are important tools for weed control in modern agriculture. In the search for potential herbicidal natural products from fungal species, harzianum A and B were identified from the biofertilizer fungus, Trichoderma brevicompactum. In the phytotoxicity assays on the dicot species Brassica chinensis, harzianum A and B reduced both shoot and root lengths at low concentrations and inhibited the seed germination at 2 μg mL.

Secondary metabolites from hypocrealean entomopathogenic fungi: genomics as a tool to elucidate the encoded parvome.

Covering: 2014 up to the third quarter of 2019 Hypocrealean entomopathogenic fungi (HEF) produce a large variety of secondary metabolites (SMs) that are prominent virulence factors or mediate various interactions in the native niches of these organisms. Many of these SMs show insecticidal, immune system modulatory, antimicrobial, cytotoxic and other bioactivities of clinical or agricultural significance. Recent advances in whole genome sequencing technologies and bioinformatics have revealed many biosynthetic gene clusters (BGCs) potentially involved in SM production in HEF.

Secondary metabolites from hypocrealean entomopathogenic fungi: novel bioactive compounds.

Covering: 2014 up to the third quarter of 2019 Entomopathogens constitute a unique, specialized trophic subgroup of fungi, most of whose members belong to the order Hypocreales (class Sordariomycetes, phylum Ascomycota). These Hypocrealean Entomopathogenic Fungi (HEF) produce a large variety of secondary metabolites (SMs) and their genomes rank highly for the number of predicted, unique SM biosynthetic gene clusters. SMs from HEF have diverse roles in insect pathogenicity as virulence factors by modulating various interactions between the producer fungus and its insect host.

Methylglucosylation of Phenolic Compounds by Fungal Glycosyltransferase-Methyltransferase Functional Modules.

Glycosylation endows both natural and synthetic small molecules with modulated physicochemical and biological properties. Plant and bacterial glycosyltransferases capable of decorating various privileged scaffolds have been extensively studied, but those from kingdom Fungi still remain underexploited. Here, we use a combination of genome mining and heterologous expression techniques to identify four novel glycosyltransferase-methyltransferase (GT-MT) functional modules from Hypocreales fungi.

Rational Reprogramming of O-Methylation Regioselectivity for Combinatorial Biosynthetic Tailoring of Benzenediol Lactone Scaffolds.

O-Methylation modulates the pharmacokinetic and pharmacodynamic (PK/PD) properties of small-molecule natural products, affecting their bioavailability, stability, and binding to targets. Diversity-oriented combinatorial biosynthesis of new chemical entities for drug discovery and optimization of known bioactive scaffolds during drug development both demand efficient O-methyltransferase (OMT) biocatalysts with considerable substrate promiscuity and tunable regioselectivity that can be deployed in a scalable and sustainable manner. Here we demonstrate efficient total biosynthetic and biocatalytic platforms that use a pair of fungal OMTs with orthogonal regiospecificity to produce unnatural O-methylated benzenediol lactone polyketides.

Extracellularly oxidative activation and inactivation of matured prodrug for cryptic self-resistance in naphthyridinomycin biosynthesis.

Understanding how antibiotic-producing bacteria deal with highly reactive chemicals will ultimately guide therapeutic strategies to combat the increasing clinical resistance crisis. Here, we uncovered a distinctive self-defense strategy featured by a secreted oxidoreductase NapU to perform extracellularly oxidative activation and conditionally overoxidative inactivation of a matured prodrug in naphthyridinomycin (NDM) biosynthesis from NRRL 8034. It was suggested that formation of NDM first involves a nonribosomal peptide synthetase assembly line to generate a prodrug.