The global regulator LaeA controls secondary metabolism in diverse Aspergillus species. Here we explored its role in regulation of itaconic acid production in . To understand its role in regulating metabolism, we deleted and overexpressed and assessed the transcriptome, proteome, and secreted metabolome prior to and during initiation of phosphate limitation induced itaconic acid production.
View Article and Find Full Text PDFOleaginous yeast, such as , are logical organisms for production of higher energy density molecules like lipids and terpenes. We demonstrate that transgenic strains expressing an α-zingiberene synthase gene from lemon basil or Hall's panicgrass can produce up to 17 mg/L α-zingiberene in yeast extract peptone dextrose (YPD) medium containing 4% glucose. The transgenic strain was further examined in 8% glucose media with C/N ratios of 20 or 100, and YPD.
View Article and Find Full Text PDFBiological engineering of microorganisms to produce value-added chemicals is a promising route to sustainable manufacturing. However, overproduction of metabolic intermediates at high titer, rate, and yield from inexpensive substrates is challenging in non-model systems where limited information is available regarding metabolic flux and its control in production conditions. Integrated multi-omic analyses of engineered strains offers an in-depth look at metabolites and proteins directly involved in growth and production of target and non-target bioproducts.
View Article and Find Full Text PDFThe filamentous fungus Aspergillus terreus has been successfully used for industrial production of itaconic acid (IA) for many years. The IA biosynthesis pathway has recently been characterized at a molecular genetic level as an IA gene cluster by a clone-based transcriptomic approach. The cluster consists of four genes, including genes for cis-aconitic acid decarboxylase (cadA), a predicted transcription factor (tf), a mitochondrial organic acid transporter (mttA) and an MFS (major facilitator superfamily) type transporter (mfsA).
View Article and Find Full Text PDFBackground: Efficient and economically viable production of biofuels from lignocellulosic biomass is dependent on mechanical and chemical pretreatment and enzymatic hydrolysis of plant material. These processing steps yield simple sugars as well as plant-derived and process-added organic acids, sugar-derived dehydration products, aldehydes, phenolics and other compounds that inhibit the growth of many microorganisms. is an oleaginous yeast capable of robust growth on a variety of sugars and lipid accumulation on pretreated lignocellulosic substrates making it attractive as an industrial producer of biofuels.
View Article and Find Full Text PDFThe objective of this study was to disrupt the non-homologous end-joining (NHEJ) pathway gene (Lsku70Δ) and evaluate the effects of selected gene deletions related to glycogen synthesis (LsGSY1) and lipid degradation (LsMFE1, LsPEX10, and LsTGL4) on lipid production in the oleaginous yeast Lipomyces starkeyi. Disruption of the NHEJ pathway to reduce the rate of non-homologous recombination is a common approach used to overcome low-efficiency targeted deletion or insertion in various organisms. Here, the homologue of the LsKU70 gene was identified and disrupted in L.
View Article and Find Full Text PDFWood-degrading fungi use a sequence of oxidative and hydrolytic mechanisms to loosen lignocellulose and then release and metabolize embedded sugars. These temporal sequences have recently been mapped at high resolution using directional growth on wood wafers, revealing previously obscured dynamics as fungi progressively colonize wood. Here, we applied secretomics in the same wafer design to track temporal trends on aspen decayed by fungi with distinct nutritional modes: two brown rot (BR) fungi ( and ) and two white rot (WR) fungi ( and ).
View Article and Find Full Text PDFTwo-dimensional gas chromatography coupled with time-of-flight mass spectrometry is a powerful tool for identifying and quantifying chemical components in complex mixtures. It is often used to analyze gasoline, jet fuel, diesel, bio-diesel and the organic fraction of bio-crude/bio-oil. In most of those analyses, the first dimension of separation is non-polar, followed by a polar separation.
View Article and Find Full Text PDFAspergillus fumigatus is the primary pathogen causing the devastating pulmonary disease Invasive Aspergillosis in immunocompromised individuals. There is high genomic synteny between A. fumigatus and closely related rarely pathogenic Neosartorya fischeri and Aspergillus clavatus genomes.
View Article and Find Full Text PDFEnvironmental adaptability is critical for survival of the fungal human pathogen Aspergillus fumigatus in the immunocompromised host lung. We hypothesized that exposure of the fungal pathogen to human serum would lead to significant alterations to the organism's physiology, including metabolic activity and stress response. Shifts in functional pathway and corresponding enzyme reactivity of A.
View Article and Find Full Text PDFFungi inhabit every natural and anthropogenic environment on Earth. They have highly varied life-styles including saprobes (using only dead biomass as a nutrient source), pathogens (feeding on living biomass), and symbionts (co-existing with other organisms). These distinctions are not absolute as many species employ several life styles (e.
View Article and Find Full Text PDFBrown rot basidiomycetes have an important ecological role in lignocellulose recycling and are notable for their rapid degradation of wood polymers via oxidative and hydrolytic mechanisms. However, most of these fungi apparently lack processive (exo-acting) cellulases, such as cellobiohydrolases, which are generally required for efficient cellulolysis. The recent sequencing of the Postia placenta genome now permits a proteomic approach to this longstanding conundrum.
View Article and Find Full Text PDFThe continued fast pace of fungal genome sequence generation has enabled proteomic analysis of a wide variety of organisms that span the breadth of the Kingdom Fungi. There is some phylogenetic bias to the current catalog of fungi with reasonable DNA sequence databases (genomic or EST) that could be analyzed at a global proteomic level. However, the rapid development of next generation sequencing platforms has lowered the cost of genome sequencing such that in the near future, having a genome sequence will no longer be a time or cost bottleneck for downstream proteomic (and transcriptomic) analyses.
View Article and Find Full Text PDFWe used computational and mass spectrometric approaches to characterize the Aspergillus niger secretome.The 11,200 gene models predicted in the genome of A. niger strain ATCC 1015 were the data source for the analysis.
View Article and Find Full Text PDFHigh-throughput liquid chromatography mass spectrometry (LC-MS)-based proteomic analysis has emerged as a powerful tool for functional annotation of genome sequences. These analyses complement the bioinformatic and experimental tools used for deriving, verifying, and functionally annotating models of genes and their transcripts. Furthermore, proteomics extends verification and functional annotation to the level of the translation product of the gene model.
View Article and Find Full Text PDFFungal lignin-degrading systems likely include membrane-associated proteins that participate in diverse processes such as uptake and oxidation of lignin fragments, production of ligninolytic secondary metabolites, and defense of the mycelium against ligninolytic oxidants. Little is known about the nature or regulation of these membrane-associated components. We grew the white rot basidiomycete Phanerochaete chrysosporium on cellulose or glucose as the carbon source and monitored the mineralization of a (14)C-labeled synthetic lignin by these cultures to assess their ligninolytic competence.
View Article and Find Full Text PDFThe use of a phosphoprotein isotope-coded affinity tag (PhIAT), which employs differential isotopic labeling and biotinylation, has been shown capable of enriching and identifying mixtures of low-abundance phosphopeptides. A denatured solution of beta-casein was labeled using the PhIAT method, and after proteolytic digestion, the labeled peptides were isolated using immobilized avidin. The recovered peptides were separated by capillary reversed-phase liquid chromatography and identified by tandem mass spectrometry.
View Article and Find Full Text PDFGlobal analysis of biological systems is becoming increasingly feasible as technologies that facilitate genome-wide analyses of gene expression are developed. Proteomics is the global analysis of expressed proteins (including posttranslational modifications) and seeks to establish the relationship between genome sequence, expressed proteins, protein-protein interactions, and cell and tissue phenotype. While the relative abundance of transcripts can be quantified using gene expression microarrays, the identification and quantitation of expressed proteins is more challenging.
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