The glucoamylase-encoding gene (glaA) from Aspergillus oryzae was cloned using its cDNA as a probe, which had been isolated previously. From comparison of nucleotide (nt) sequences of genomic clones with its cDNA, the glaA gene was found to contain four short putative introns, 45-56 nt in length. The A. oryzae glaA gene shared 62% homology at the nt level with the A. niger glaA gene with the four introns located at the same position. The 5'-flanking region contained a TATA box at nt-72 from the start codon, and two putative CAAT sequences at nt-87 and -331. Genomic Southern analysis and physical mapping showed that the glaA gene is located on the smallest chromosome (3.4 Mb) of six separated bands of chromosomes. Clones containing the glaA gene, when re-introduced intro A. oryzae, resulted in a three- to eightfold increase in glucoamylase activity.
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http://dx.doi.org/10.1016/0378-1119(91)90500-b | DOI Listing |
Int J Biol Macromol
January 2025
Science Center for Future Foods, Jiangnan University, Wuxi 214122, China; School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China. Electronic address:
L-asparaginase (L-ASNase) can hydrolyze L-asparagine, a precursor to acrylamide, thereby reducing toxic acrylamide formation in fried foods. Currently, commercial L-ASNases are primarily produced by wild-type (WT) filamentous fungi; however, these enzymes often exhibit rapid activity loss during high-temperature processing due to limited thermal stability. In this study, we screened a thermostable L-ASNase gene from thermophile bacteria and expressed it in Aspergillus niger to reduce acrylamide content in French fries.
View Article and Find Full Text PDFBMC Biotechnol
November 2024
School of Life Sciences, Anhui University, Hefei, 230601, China.
Background: The laccase Lcc9 from Coprinopsis cinerea has optimal catalytic activity at moderate to alkaline pH conditions, making it invaluable for industrial applications. However, C. cinerea naturally secretes Lcc9 at low expression levels, which limits the industrial application of Lcc9 on a large scale.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Biology and Biological Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, PR China. Electronic address:
Aspergillus niger is a cell factory widely used in industries to produce proteases, organic acids, drugs, and other substances. The hyphal morphology of A. niger is a complex differentiated elongated tubular structure, which limits its basic research and application.
View Article and Find Full Text PDFFungal Biol Biotechnol
October 2024
Institute Biology Leiden, Microbial Sciences, Fungal Genetics and Biotechnology, Leiden University, Sylviusweg 72, Leiden, 2333 BE, The Netherlands.
Background: Aspergillus niger is well-known for its high protein secretion capacity and therefore an important cell factory for homologous and heterologous protein production. The use of a strong promoter and multiple gene copies are commonly used strategies to increase the gene expression and protein production of the gene of interest (GOI). We recently presented a two-step CRISPR/Cas9-mediated approach in which glucoamylase (glaA) landing sites (GLSs) are introduced at predetermined sites in the genome (step 1), which are subsequently filled with copies of the GOI (step 2) to achieve high expression of the GOI.
View Article and Find Full Text PDFJ Agric Food Chem
October 2023
Key Laboratory of Food Bioengineering (China National Light Industry), College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
CRISPR/Cas9 system-mediated multi-copy expression of an alkaline serine protease (S8) from was successfully built in . Furthermore, AoproS8 was continuously knocked in the , , and gene loci in to construct multi-copy expression strains. The yield of the AoproS8 3.
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