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Research has been conducted on Aspergillus niger endoglucanase EglC. Results indicate that this enzyme has a new function which is involved in the plant cell wall polysaccharide degradation by A. niger.

Two alpha-L-rhamnosidases from Aspergillus aculeatus are described. These enzymes are used in the food and beverage industry and Aspergillus aculeatus is a good source of pectinolytic enzymes.

Two Aspergillus niger cellobiohydrolase-encoding genes must have D-xylose and the xylanolytic transcriptional activator XlnR for expression to occur. A. niger is a filamentous fungus. Cellulase-encoding genes are regulated at the transcription level.

A gene encoding a third alpha-galactosidase (AglB) from Aspergillus niger has been cloned and sequenced. An alignment of AglB amino acid sequence with alpha-galatosidases revealed that it belongs to a family of alpha-galatosidases that also includes A. niger AglA. The expression of the genes aglA, aglB, aglC and lacA was studied using monomeric, oligomeric and polymeric compounds as growth substrates. All four genes have distinct expression patterns which seem to mirror the natural substrates of the encoded proteins.

A study was conducted on the expression of genes encoding enzymes involved in xylan degradation and two endoglucanases involved in cellulose degradation at the mRNA level in the fungus Aspergillus niger. Findings showed that the transcriptional activator XlnR regulates the transcription of three genes encoding the xylanolytic enzymes. XlnR activated the transcription of two endoglucanase-encoding genes, eglA and eglB, indicating that transcriptional regulation by XlnR goes beyond the genes encoding xylanolytic enzymes.

Research was conducted to examine the molecular cloning and transcriptional regulation of the Aspergillus nidulans xlnD gene encoding the 85-kDA beta-xylosidase. The primary structure of the protein had considerable similarity to the primary structures of the Trichoderma reesei and Aspergillus niger beta-xylodases. Western blot analysis revealed elevated levels of production of the enzyme in overexpressing transformants showing that the cloned sequences existing in pXE1 encode the previously characterized 85-kDa beta-xylosidase.

Saccharomyces cerevisiae cells expressing Aspergillus nidulans xlnA and xlnB genes produce X(sub 22) and X(sub 24) xylanases that hydrolyze xylan. The cells expressing xlnA show greater xylanase activity than those expressing xlnB. Xylanase activity in recombinant S. cerevisiae is less than that in A. nidulans cells transformed with the xlnA and xlnB genes and their upstream amino acids. The genes are open reading frames containing introns. The xlnA encoded protein has 187 residues and a molecular weight of 20,247 while the xlnB encoded protein has 182 residues and a molecular weight of 20,088.

Three different glycosylated glycosyl hydrolases are secreted by the Aspergillus niger. The hydrolases degrade the plant cell wall polysaccharide L-arabinan:alpha-L-arabinofuranosidases (ABF). The secretion requires the nucleotide sequence that is cloned by the gene encoding ABF A from Aspergillus niger. The coding region that secretes the hydrolases has seven nitrons.

A fast, quantitative real-time PCR (qPCR)-based hierarchical experimental design is used to determine the biological and technical variation between fermentation in the filamentous fungus Aspergillus niger batch fermentations by optimization of protocols and procedures. The results confirmed the hypothesis that the D-xylose signal is interpreted by the fungus as the availability of a multitude of complex polysaccharides and provides improved method for the generation of high-quality qPCR and microarray data from fermentation of the filamentous fungus Aspergilluss niger.

Aspergillus niger is a filamentous fungus that is extensively used in industrial fermentations for protein expression and the production of organic acids. Inherent biosynthetic capabilities, such as the capacity to secrete these biomolecules in high amounts, make A. niger an attractive production host. Although A. niger is renowned for this ability, the knowledge of the molecular components that underlie its production capacity, intercellular trafficking processes and secretion mechanisms is far from complete. Here, we introduce a standardized set of tools, consisting of an N-terminal GFP-actin fusion and codon optimized eforRed chromoprotein. Expression of the GFP-actin construct facilitates visualization of the actin filaments of the cytoskeleton, whereas expression of the chromoprotein construct results in a clearly distinguishable red phenotype. These experimentally validated constructs constitute the first set of standardized A. niger biomarkers, which can be used to study morphology, intercellular trafficking, and secretion phenomena.

Cyanophycin or cyanophycin granule peptide is a protein that results from non-ribosomal protein synthesis in microorganisms such as cyanobacteria. The amino acids in cyanophycin can be used as a feedstock in the production of a wide range of chemicals such as acrylonitrile, polyacrylic acid, 1,4-butanediamine, and urea. In this study, an auxotrophic mutant (Rhizopus oryzae M16) of the filamentous fungus R. oryzae 99-880 was selected to express cyanophycin synthetase encoding genes. These genes originated from Synechocystis sp. strain PCC6803, Anabaena sp. strain PCC7120, and a codon optimized version of latter gene. The genes were under control of the pyruvate decarboxylase promoter and terminator elements of R. oryzae. Transformants were generated by the biolistic transformation method. In only two transformants both expressing the cyanophycin synthetase encoding gene from Synechocystis sp. strain PCC6803 was a specific enzyme activity detected of 1.5 mU/mg protein. In one of these transformants was both water-soluble and insoluble cyanophycin detected. The water-soluble fraction formed the major fraction and accounted for 0.5% of the dry weight. The water-insoluble CGP was produced in trace amounts. The amino acid composition of the water-soluble form was determined and constitutes of equimolar amounts of arginine and aspartic acid.