Journal of Industrial Microbiology & Biotechnology

Hybrid natural products are compounds that originate from diverse biosynthetic pathways and undergo a conjugation process, which enables them to expand their chemical diversity and biological functionality. Terpene-amino acid meroterpenoids have garnered increasing attention in recent years, driven by the discovery of noteworthy examples such as the anthelmintic CJ-12662, the insecticidal paeciloxazine, and aculene A (1). In the biosynthesis of terpene-amino acid natural products, single module nonribosomal peptide synthetases (NRPSs) have been identified to involve in the esterification step, catalyzing the fusion of modified terpene and amino acid components...

Rhodotorula toruloides is being developed for use in industrial biotechnology processes because of its favorable physiology. This includes its ability to produce and store large amounts of lipids in the form of intracellular lipid bodies. Nineteen strains were characterized for mating type, ploidy, robustness for growth, and accumulation of lipids on inhibitory switchgrass hydrolysate (SGH). Mating type was determined using a novel PCR-based assay, which was validated using the classical microscopic test. Three of the strains were heterozygous for mating type (A1/A2)...

Evaluating the safety of probiotic microorganisms is an important part of the development of probiotic products. In this study, we have performed a systematic safety assessment of Limosilactobacillus reuteri ATCC PTA 4659 based on genome analysis, antibiotic susceptibility testing, phenotypic characterization, and a human clinical safety study. Genome sequence analysis showed that the strain is free from virulence and antibiotic resistance genes. Connected to this, phenotypic characterization showed that the strain is susceptible to the main classes of antibiotics...

Gas chromatography-tandem mass spectrometry with electron ionization (GC-EI-MS/MS) provides rich information on stable-isotope labeling for 13C-metabolic flux analysis (13C-MFA). To pave the way for the routine application of tandem MS data for metabolic flux quantification, we aimed to compile a comprehensive library of GC-EI-MS/MS fragments of tert-butyldimethylsilyl (TBDMS) derivatized proteinogenic amino acids. First, we established an analytical workflow which combines high resolution gas chromatography-quadrupole time-of-flight mass spectrometry (GC-EI-QTOFMS) and fully 13C-labeled biomass to identify and structurally elucidate tandem MS amino acid fragments...

There have been a considerable number of antifungal studies that evaluated natural products, such as medicinal plants, and their secondary metabolites, (phenolic compounds, alkaloids), essential oils, as well as propolis extracts. These studies have investigated natural antifungal substances for use as food preservatives, medicinal agents, or in agriculture as green pesticides because they represent an option of safe, low impact and environmentally friendly antifungal compounds, however, few have studied these natural products as an alternative to disinfection/sanitation for indoor air or environmental surfaces...

Exposure to ultraviolet (UV) rays is a known risk factor for skin cancer, which can be notably mitigated through the application of sun care products. However, escalating concerns regarding the adverse health and environmental impacts of synthetic anti-UV chemicals underscore a pressing need for the development of biodegradable and eco-friendly sunscreen ingredients. Mycosporine-like amino acids (MAAs) represent a family of water-soluble anti-UV natural products synthesized by various organisms. These compounds can provide a two-pronged strategy for sun protection as they not only exhibit a superior UV absorption profile but also possess the potential to alleviate UV-induced oxidative stresses...

The off-flavor of Pichia pastoris strains is a negative characteristic of proteins overexpressed with this yeast. In the present study, the P. pastoris GS115 overexpressing a α-L-rhamnosidase was taken as the example to characterize the off-flavor via sensory evaluation, gas chromatography-mass spectrometer (GC-MS), gas chromatography-olfaction (GC-O), and omission test. The result showed the off-flavor was attributed to the strong sweaty note, moderate metallic and plastic notes. Four volatile compounds, i...

Coupling transcription of a cloned gene to the lac operon with induction by isopropylthio-β-galactoside (IPTG) has been a favoured approach for recombinant protein expression using Escherichia coli as a heterologous host for more than six decades. Despite a wealth of experimental data gleaned over this period, a quantitative relationship between extracellular IPTG concentration and consequent levels of recombinant protein expression remains surprisingly elusive across a broad spectrum of experimental conditions...

Microbial bioproduction often faces challenges related to populational heterogeneity, where cells exhibit varying biosynthesis capabilities. Bioproduction heterogeneity can stem from genetic and non-genetic factors, resulting in decreased titer, yield, stability, and reproducibility. Consequently, understanding and controlling bioproduction heterogeneity are crucial for enhancing the economic competitiveness of large-scale biomanufacturing. In this review, we provide a comprehensive overview of current understandings of the various mechanisms underlying bioproduction heterogeneity...

Yarrowia lipolytica naturally saves carbon excess as storage lipids. Engineering efforts allow redirecting the high precursor flux required for lipid synthesis towards added-value chemicals such as polyketides, flavonoids, and terpenoids. To redirect precursor flux from storage lipids to other products, four genes involved in triacylglycerol and sterol ester synthesis (DGA1, DGA2, LRO1, ARE1) can be deleted. To elucidate the effect of the deletions on cell physiology and regulation, we performed chemostat cultivations under carbon and nitrogen limitation, followed by transcriptome analysis...

The emergence of multidrug-resistant Pseudomonas aeruginosa in healthcare settings poses a tremendous challenge to traditional antibiotic therapy. P. aeruginosa utilizes quorum sensing (QS) to coordinate the production of virulence factors and the formation of drug-resistant biofilms. QS is mediated by signal compounds produced by P. aeruginosa as well as signal molecules produced by other non-pseudomonad bacteria. A potential strategy to prevent bacterial pathogenicity is utilizing enzymes to interfere with QS...

Genkwanin has various significant roles in nutrition, biomedicine, and pharmaceutical biology. Previously, this compound has been chiefly produced by plant-originated extraction or chemical synthesis. However, due to increasing concern and demand for safe food and environmental issues, the biotechnological production of genkwanin and other bioactive compounds based on safe, cheap, and renewable substrates has gained much interest. This paper described recombinant Escherichia coli-based co-culture engineering that was reconstructed for the de novo production of genkwanin from D-glucose...

The biotechnological production of methyl ketones is a sustainable alternative to the fossil-derived chemical production. To date, the best host for microbial production of methyl ketones is a genetically engineered Pseudomonas taiwanensis VLB120 ∆6 pProd strain, achieving yields of 101mgg-1 on glucose in batch cultivations. For competitiveness with the petrochemical production pathway, however, higher yields are necessary. Co-feeding can improve the yield by fitting the carbon-to-energy ratio to the organism and the target product...

Eunicellane diterpenoids are a remarkable family of terpene natural products and have been of high interest for over five decades. Widely distributed in soft corals and rare in plants, eunicellanes were also recently identified from actinobacteria. These terpenoids have foundational 6/10-bicyclic frameworks that are frequently oxidized into structures containing transannular ether bridges. Interest in their unique structures and promising biological activities, such as the paclitaxel-like activities of eleutherobin and the sarcodictyins, have led to advancements in natural product isolation, total synthesis, medicinal chemistry, and drug lead development...

Small peptide aldehydes (SPAs) with protease inhibitory activity are naturally occurring compounds shown to be synthesized by nonribosomal peptide synthetases (NRPS). SPAs are widely used in biotechnology and have been utilized as therapeutic agents. They are also physiologically relevant and have been postulated to regulate the development of their producing microorganisms. Previously, we identified an NRPS-like biosynthetic gene cluster in Streptomyces lividans 66 that lacked a condensation (C) domain but included a tRNA-Utilizing Enzyme (tRUE) belonging to the leucyl/phenylalanyl (L/F) transferase family...

Perkinsus marinus (Perkinsea) is an osmotrophic facultative intracellular marine protozoan responsible for 'Dermo' disease in the eastern oyster, Crassostrea virginica. In 1993, three laboratories developed the in vitro culture of P. marinus in the absence of host cells. Two of the culture media and conditions went through several optimization reiterations, with one becoming the standard for the small-scale growth of Perkinsus species. Compared to most intracellular protozoan parasites, the availability of P...

Biomanufacturing could contribute as much as $30 trillion to the global economy by 2030. But the success of the growing bioeconomy depends on our ability to manufacture high-performing strains in a time- and cost-effective manner. The Design-Build-Test-Learn (DBTL) framework has proven to be an effective strain engineering approach. Significant improvements have been made in genome engineering, genotyping, and phenotyping throughput over the last couple of decades that have greatly accelerated the DBTL cycles...

Bacteria have long been a source of natural products with diverse bioactivities that have been developed into therapeutics to treat human disease. Historically, researchers have focused on a few taxa of bacteria, mainly Streptomyces and other actinomycetes. This strategy was initially highly successful and resulted in the golden era of antibiotic discovery. The golden era ended when the most common antibiotics from Streptomyces had been discovered. Rediscovery of known compounds has plagued natural product discovery ever since...

Microbial biofilm contamination is a widespread problem that requires precise and prompt detection techniques to effectively control its growth. Microfabricated electrochemical impedance spectroscopy (EIS) biosensors offer promise as a tool for early biofilm detection and monitoring of elimination. This study utilized a custom flow cell system with integrated sensors to make real-time impedance measurements of biofilm growth under flow conditions, which were correlated with confocal laser scanning microscopy (CLSM) imaging...

Biogenic synthesis of inorganic nanomaterials has been demonstrated for both wild and engineered bacterial strains. In many systems the nucleation and growth of nanomaterials is poorly controlled and requires concentrations of heavy metals toxic to living cells. Here we utilized the tools of synthetic biology to engineer a strain of Escherichia coli capable of synthesizing cadmium sulfide nanoparticles from low concentrations of reactants with control over the location of synthesis. Informed by simulations of bacterially-assisted nanoparticle synthesis, we created a strain of E...