Genome Combination Improvement Strategy Promotes Efficient Spinosyn Biosynthesis in .

Spinosyns are secondary metabolites produced by known for their potent insecticidal properties and broad pesticidal spectrum. We report significant advancements in spinosyn biosynthesis achieved through a genome combination improvement strategy in . By integrating modified genome shuffling with ultraviolet mutation and multiomics analysis, we developed a high-yield spinosyn strain designated as YX2.

ARTP/NTG Compound Mutagenesis Improved the Spinosad Production and the Insecticidal Virulence of .

Spinosad is an efficient and broad-spectrum environmentally friendly biopesticide, but its low yield in wild-type limits its further application. ARTP/NTG compound mutagenesis was used in this study to improve the spinosad titer of and obtain a high-yield mutant-NT24. Compared with the wild-type strain, the fermentation cycle of NT24 was shortened by 2 days and its maximum titer of spinosad reached 858.

Combinatorial metabolic engineering strategy of precursor pools for the yield improvement of spinosad in Saccharopolyspora spinosa.

Spinosad is an insecticide produced by Saccharopolyspora spinosa, and its larvicidal activity is considered a promising approach to combat crop pests. The aim of this study was to enhance the synthesis of spinosad through increasing the supply of acyl-CoAs precursor by the following steps. (i) Engineering the β-oxidation pathway by overexpressing key genes within the pathway to promote the synthesis of spinosad.

Engineered probiotic E.coli Nissle 1917 for release PTEN to improve the tumor microenvironment and suppress tumor growth.

The cancer is one of the diseases of serious threat to people's health and life nowadays. But heterogeneity, drug resistance and treatment side effects of cancer, traditional treatments still have limitations. Tumor-targeting probiotics with a well-established Biosafety and efficient targeting as a delivery vectors to deliver anticancer genes or antitumor drugs to tumor microenvironment has attracted much attention in cancer therapies.

Identification and characterization of a novel type II toxin-antitoxin system in Aeromonas veronii.

The bacterial type II toxin-antitoxin (TA) system is a rich genetic element that participates in various physiological processes. Aeromonas veronii is the main bacterial pathogen threatening the freshwater aquaculture industry. However, the distribution of type II TA system in A.

Application and research progress of ARTP mutagenesis in actinomycetes breeding.

Atmospheric and room temperature plasma (ARTP) is an emerging artificial mutagenesis breeding technology. In comparison to traditional physical and chemical methods, ARTP technology can induce DNA damage more effectively and obtain mutation strains with stable heredity more easily after screening. It possesses advantages such as simplicity, safety, non-toxicity, and cost-effectiveness, showing high application value in microbial breeding.

Enhanced triacylglycerol metabolism contributes to the efficient biosynthesis of spinosad in .

Triacylglycerol (TAG) is crucial for antibiotic biosynthesis derived from , as it serves as an important carbon source. In this study, the supplementation of exogenous TAG led to a 3.92-fold augmentation in spinosad production.

Function and Global Regulation of Type III Secretion System and Flagella in Entomopathogenic Nematode Symbiotic Bacteria.

Currently, it is widely accepted that the type III secretion system (T3SS) serves as the transport platform for bacterial virulence factors, while flagella act as propulsion motors. However, there remains a noticeable dearth of comparative studies elucidating the functional disparities between these two mechanisms. Entomopathogenic nematode symbiotic bacteria (ENS), including and , are Gram-negative bacteria transported into insect hosts by or .

Isolation and Characterization of a Novel Virulent Phage ASG01 of and Its Cell Wall Hydrolase Activity.

is an important pathogen that causes furunculosis in trout and salmon with high morbidity and mortality, resulting in significant economic losses in aquaculture. Overuse of antibiotics has led to the continuous emergence of drug-resistant strains. Hence, there is an urgent need to find an alternative environmentally friendly antimicrobial agent.

Streptomyces enissocaesilis L-82 has broad-spectrum antibacterial activity and promotes growth for Carassius auratus.

Aeromonas is the main pathogen causing bacterial diseases in fish. The disadvantages of chemical drugs to control fish diseases have been highlighted, and it is urgent to find an eco-friendly control method. In this study, an actinomycete strain with antibacterial activity against fish pathogenic bacteria was screened from soil samples.

Discovery of an antitumor compound from xenorhabdus stockiae HN_xs01.

Xenorhabdus, known for its symbiotic relationship with Entomopathogenic nematodes (EPNs), belongs to the Enterobacteriaceae family. This dual-host symbiotic nematode exhibits pathogenic traits, rendering it a promising biocontrol agent against insects. Our prior investigations revealed that Xenorhabdus stockiae HN_xs01, isolated in our laboratory, demonstrates exceptional potential in halting bacterial growth and displaying anti-tumor activity.

Effects of a Pirin-like protein on strain growth and spinosad biosynthesis in Saccharopolyspora spinosa.

Pirin family proteins perform a variety of biological functions and widely exist in all living organisms. A few studies have shown that Pirin family proteins may be involved in the biosynthesis of antibiotics in actinomycetes. However, the function of Pirin-like proteins in S.

Protective effects of chlorogenic acid on growth, intestinal inflammation, hepatic antioxidant capacity, muscle development and skin color in channel catfish Ictalurus punctatus fed an oxidized fish oil diet.

Under oxidative stress condition, the protective effects of dietary chlorogenic acid (CGA) supplementation on liver antioxidant capacity, intestinal inflammation and barrier function, muscle development and skin coloration in channel catfish Ictalurus punctatus were explored in the current study. With that purpose, I. punctatus were fed five experimental diets containing 2% fresh fish oil (FFO, 9.

Recombineering using RecET-like recombinases from Xenorhabdus and its application in mining of natural products.

Xenorhabdus can produce a large number of secondary metabolites with insecticidal, bacteriostatic, and antitumor activities. Efficient gene editing tools will undoubtedly facilitate the functional genomics research and bioprospecting in Xenorhabdus. In this study, BlastP analysis using the amino acid sequences of Redαβ or RecET recombinases as queries resulted in the identification of an operon (XBJ1_operon 0213) containing RecET-like recombinases encoding genes from the genome of Xenorhabdus bovienii strain SS-2004.

A new isolate of Streptomyces lateritius (Z1-26) with antibacterial activity against fish pathogens and immune enhancement effects on crucian carp (Carassius auratus).

The Streptomyces lateritius Z1-26 was isolated from soil samples which showed broad-spectrum antibacterial activity against a broad range of fish pathogens. The In Vivo Imaging System (IVIS) monitored that strain Z1-26 could survive and colonize in the gills and abdomen of crucian carp. The effects of dietary supplementation with strain Z1-26 were evaluated with respect to the growth performance, antioxidant capacity, and immune response of crucian carp.

A novel tumor-targeting strain of exhibits potent biological activities.

are symbionts of soil entomopathogenic nematodes of the genus presenting two distinct forms in their life cycle, and can produce a broad range of bioactive compounds. In this study, a novel strain HN_xs01 was isolated from a soil sample via an entrapment method using nematodes. The supernatants of strain HN_xs01 exhibited antimicrobial properties against Gram-negative and Gram-positive bacteria, and insecticidal properties against larvae, and antitumor properties as well.

Screening of new Paenibacillus polymyxa S3 and its disease resistance of grass carp (Ctenopharyngodon idellus).

A new strain of Paenibacillus polymyxa S3 with antagonistic effects on 11 major fish pathogens (especially Aeromonas hydrophila), but had no toxicity to grass carp, was screened from the sediment of fishponds. In vivo colonization studies showed that strain S3 could be colonized and distributed in the gill and abdomen of the grass carp. Bioassay results showed that the weight growth rate of grass carp in the strain S3 oral group (16.

The Global Regulator PhoU Positively Controls Growth and Butenyl-Spinosyn Biosynthesis in .

Butenyl-spinosyn, a highly effective biological insecticide, is produced by . However, its application has been severely hampered by its low yield. Recent studies have shown that PhoU plays a pivotal role in regulating cell growth, secondary metabolite biosynthesis and intracellular phosphate levels.

Aeromonas veronii infection remarkably increases expression of lysozymes in grass carp (Ctenopharyngodon idellus) and injection of lysozyme expression cassette along with QCDC adjuvant significantly upregulates immune factors and decreases cumulative mortality.

Aeromonas veronii AvX005 is a pathogenic bacterium with high toxicity to grass carp (Ctenopharyngodon idellus). The expression levels of g-type (goose-type lysozyme, Lys-g) and c-type lysozyme (chicken-type lysozyme, Lys-c) in the spleen of grass carp infected with AvX005 were significantly increased by approximately 4.5 times and 27 times, respectively.

Biosynthesis of Glidomides and Elucidation of Different Mechanisms for Formation of β-OH Amino Acid Building Blocks.

Nonribosomal peptide synthetases (NRPSs) can incorporate nonproteinogenic amino acids into peptidyl backbones to increase structural diversity. Genome mining of Schlegelella brevitalea led to the identification of a class of linear lipoheptapeptides, glidomides, featuring two unusual residues: threo-β-OH-L-His and threo-β-OH-D-Asp. The β-hydroxylation of Asp and His is catalyzed by the nonheme Fe /α-ketoglutarate-dependent β-hydroxylases GlmD and GlmF, respectively.

ARTP and NTG compound mutations improved Cry protein production and virulence of Bacillus thuringiensis X023.

A high production mutated strain Bacillus thuringiensis X023PN (BtX023PN) was screened from the wild strain Bacillus thuringiensis X023 (BtX023) after atmospheric and room temperature plasma (ARTP) and nitrosoguanidine (NTG) mutation. BtX023PN grows faster than the wild strain, and its lysis of mother cell was 6 h ahead BtX023, but the ability of sporulation was significantly reduced. Bioassay indicated that compared with the wild type strain, the virulence of BtX023PN against Plutella xylostella (P.

A TetR family transcriptional regulator, SP_2854 can affect the butenyl-spinosyn biosynthesis by regulating glucose metabolism in Saccharopolyspora pogona.

Background: Butenyl-spinosyn produced by Saccharopolyspora pogona exhibits strong insecticidal activity and a broad pesticidal spectrum. Currently, important functional genes involve in butenyl-spinosyn biosynthesis remain unknown, which leads to difficulty in efficiently understanding its regulatory mechanism, and improving its production by metabolic engineering.

Results: Here, we identified a TetR family transcriptional regulator, SP_2854, that can positively regulate butenyl-spinosyn biosynthesis and affect strain growth, glucose consumption, and mycelial morphology in S.

Effect of pII key nitrogen regulatory gene on strain growth and butenyl-spinosyn biosynthesis in Saccharopolyspora pogona.

PII signal transduction proteins are widely found in bacteria and plant chloroplast, and play a central role in nitrogen metabolism regulation, which interact with many key proteins in metabolic pathways to regulate carbon/nitrogen balance by sensing changes in concentrations of cell-mediated indicators such as α-ketoglutarate. In this study, the knockout strain Saccharopolyspora pogona-ΔpII and overexpression strain S. pogona-pII were constructed using CRISPR/Cas9 technology and the shuttle vector POJ260, respectively, to investigate the effects on the growth and secondary metabolite biosynthesis of S.

Pathogenicity of fish pathogen Pseudomonas plecoglossicida and preparation of its inactivated vaccine.

Many fishes infected with Pseudomonas plecoglossicida generally suffer from "visceral white spot disease" or even die. In this study, a dominant pathogen strain was isolated from the intestinal tract of diseased crucian carp in the Wangcheng Lake area, Changsha, and it was identified as P. plecoglossicida.

Promoting Butenyl-spinosyn Production Based on Omics Research and Metabolic Network Construction in .

Understanding the metabolism of on a global scale is essential for manipulating its metabolic capabilities to improve butenyl-spinosyn biosynthesis. Here, we combined multiomics analysis to parse genomic information, construct a metabolic network, and mine important functional genes that affect the butenyl-spinosyn biosynthesis. This research not only elucidated the relationship between butenyl-spinosyn biosynthesis and the primary metabolic pathway but also showed that the low expression level and continuous downregulation of the cluster and the competitive utilization of acetyl-CoA were the main reasons for reduced butenyl-spinosyn production.