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Aspergillus niger

About: Aspergillus niger is a research topic. Over the lifetime, 9950 publications have been published within this topic receiving 198000 citations.


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Journal ArticleDOI
TL;DR: A novel gene with sequence similarity to plant expansins, isolated from the cellulolytic fungus Trichoderma reesei, is described, which has an N-terminal fungal type cellulose binding domain connected by a linker region to the expansin-like domain.
Abstract: Plant cell wall proteins called expansins are thought to disrupt hydrogen bonding between cell wall polysaccharides without hydrolyzing them. We describe here a novel gene with sequence similarity to plant expansins, isolated from the cellulolytic fungus Trichoderma reesei. The protein named swollenin has an N-terminal fungal type cellulose binding domain connected by a linker region to the expansin-like domain. The protein also contains regions similar to mammalian fibronectin type III repeats, found for the first time in a fungal protein. The swollenin gene is regulated in a largely similar manner as the T. reesei cellulase genes. The biological role of SWOI was studied by disrupting the swo1 gene from T. reesei. The disruption had no apparent effect on the growth rate on glucose or on different cellulosic carbon sources. Non-stringent Southern hybridization of Trichoderma genomic DNA with swo1 showed the presence of other swollenin-like genes, which could substitute for the loss of SWOI in the disruptant. The swollenin gene was expressed in yeast and Aspergillus niger var. awamori. Activity assays on cotton fibers and filter paper were performed with concentrated SWOI-containing yeast supernatant that disrupted the structure of the cotton fibers without detectable formation of reducing sugars. It also weakened filter paper as assayed by an extensometer. The SWOI protein was purified from A. niger var. awamori culture supernatant and used in an activity assay with Valonia cell walls. It disrupted the structure of the cell walls without producing detectable amounts of reducing sugars.

438 citations

Journal ArticleDOI
TL;DR: The role played by various functional groups in the cell wall of Aspergillus niger in biosorption of lead, cadmium and copper was investigated in this paper, where the biomass was subjected to chemical treatments to modify the functional groups, carboxyl, amino and phosphate.

438 citations

Journal ArticleDOI
TL;DR: A transformation system is developed for Aspergillus niger using the amdS gene as a dominant heterologous marker for selecting transformants on the basis of acetamide utilization and it is shown that an unselected plasmid can be co‐transformed with the amdR/intA plasmids into A. niger.
Abstract: Aspergillus niger grows poorly on acetamide as a nitrogen or carbon source and lacks sequences detectably homologous to the amdS gene encoding the acetamidase of Aspergillus nidulans. We have taken advantage of these observations to develop a transformation system for A. niger using the amdS gene as a dominant heterologous marker for selecting transformants on the basis of acetamide utilization. Transformants varied in their ability to grow on amide media and the number of integrated copies of the amdS plasmid ranged from 1 or 2 to greater than 100. Southern analysis of transformants revealed that the multiple copies were integrated into the chromosome in tandem arrays. This result indicates that transformation of A. niger is more similar to mammalian cells than to yeast. Analysis of enzyme activity levels and RNA levels showed that most of the copies of amdS were expressed. Mitotic stabilities of transformants were found to be high. A transformant containing greater than 100 copies of the amdS gene was impaired in omega-amino acid utilization, a result that has also been found in A. nidulans. Since, in A. nidulans, omega-amino acids induce acetamidase via a characterizied regulatory gene (amdR/intA) this observation implies that titration of an analogous A. niger regulatory gene product by multiple amdS copies has occurred. Additional evidence suggested that the amdS gene is regulated in A. niger. It has also been shown that an unselected plasmid can be co-transformed with the amdS plasmid into A. niger.

437 citations

Journal ArticleDOI
Su-Yeon Kang1, Yun-Jin Park1, Jinwon Lee, Sung-Yong Hong1, Seung Wook Kim1 
TL;DR: The higher enzyme activities produced by A. niger KK2 is a significant advantage from the viewpoint of practical saccharification reaction and might be applied to pulp and paper industry, feed industry and chemical industry.

428 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023398
2022948
2021285
2020334
2019349