The filamentous fungus Aspergillus oryzae is an important strain in the traditional fermentation and food processing industries and is often used in the production of soy sauce, soybean paste, and liquor-making. In addition, A. oryzae has a strong capacity to secrete large amounts of hydrolytic enzymes; therefore, it has also been used in the enzyme industry as a cell factory for the production of numerous native and heterologous enzymes. However, the production and secretion of foreign proteins by A. oryzae are often limited by numerous bottlenecks that occur during transcription, translation, protein folding, translocation, degradation, transport, secretion, etc. The existence of these problems makes it difficult to achieve the desired target in the production of foreign proteins by A. oryzae. In recent years, with the decipherment of the whole genome sequence, basic research and genetic engineering technologies related to the production and utilization of A. oryzae have been well developed, such as the improvement of homologous recombination efficiency, application of selectable marker genes, development of large chromosome deletion technology, utilization of hyphal fusion techniques, and application of CRISPR/Cas9 genome editing systems. The development and establishment of these genetic engineering technologies provided a great deal of technical support for the industrial production and application of A. oryzae. This paper reviews the advances in basic research and genetic engineering technologies of the fermentation strain A. oryzae mentioned above to open up more effective ways and research space for the breeding of A. oryzae production strains in the future.

Polysaccharides are biopolymers made up of a large number of monosaccharides joined together by glycosidic bonds. Polysaccharides are widely distributed in nature: Some, such as peptidoglycan and cellulose, are the components that make up the cell walls of bacteria and plants, and some, such as starch and glycogen, are used as carbohydrate storage in plants and animals. Fungi exist in a variety of natural environments and can exploit a wide range of carbon sources. They play a crucial role in the global carbon cycle because of their ability to break down plant biomass, which is composed primarily of cell wall polysaccharides, including cellulose, hemicellulose, and pectin. Fungi produce a variety of enzymes that in combination degrade cell wall polysaccharides into different monosaccharides. Starch, the main component of grain, is also a polysaccharide that can be broken down into monosaccharides by fungi. These monosaccharides can be used for energy or as precursors for the biosynthesis of biomolecules through a series of enzymatic reactions. Industrial fermentation by microbes has been widely used to produce traditional foods, beverages, and biofuels from starch and to a lesser extent plant biomass. This review focuses on the degradation and utilization of plant homopolysaccharides, cellulose and starch; summarizes the activities of the enzymes involved and the regulation of the induction of the enzymes in well-studied filamentous fungi.

Cell-cell communication plays an important role in the development of multicellular organisms, especially with regard to their organization into tissues, as well as in control of cell growth and death and coordination of cell functions in such organisms. Animal cells communicate in two major ways: (1) they secrete chemicals that signal to cells located at various distances, and (2) they display signaling molecules at the cell surface that bind to receptors on adjacent cells. The latter mechanism is more suitable for precise and directional cell-cell communication than is the former. Indeed, the latter mechanism is widely adopted in the nervous and immune systems, where it contributes to axon guidance, antigen recognition and cell death by apoptosis. In general, the binding of a ligand to its receptor is followed by removal of the ligand-receptor complex from the cell surface and termination of the cell response. Complexes of soluble ligands and their receptors undergo endocytosis and subsequent degradation in lysosomes. By contrast, it has remained unclear how signaling is terminated after interaction of membrane-bound ligands with their receptors.The CD47-SHPS-1 system is a cell-cell communication system that consists of the transmembrane proteins CD47 and signalregulatory protein alpha (SIRPA; also known as Src-homology-2-domain-containing protein tyrosine phosphatase substrate 1, hereafter referred to as SHPS-1) (Jiang et al., 1999;Seiffert et al., 1999). CD47 and SHPS-1 interact with each other through their extracellular regions and are thought to initiate intracellular signaling in a bidirectional manner. CD47 is a member of the immunoglobulin (Ig) superfamily, possessing a V-type Ig-like extracellular domain, five putative membrane-spanning segments, and a short cytoplasmic tail (Brown and Frazier, 2001). CD47, also named IAP (integrinassociated protein), was originally identified in association with the integrin ␣v␤3. Some CD47-elicited cellular responses are thus probably mediated by integrins (Brown and Frazier, 2001). By contrast, SHPS-1, also known as SIRP␣, BIT or P84, is a transmembrane protein whose extracellular region consists of three Ig-like domains (Fujioka et al., 1996;van Beek et al., 2005). Its cytoplasmic region contains four putative tyrosine phosphorylation sites that serve as binding sites for the Src homology 2 domains of the tyrosine phosphatases SHP-1 and SHP-2 (also known as PTPN6 and PTPN11, respectively). SHPS-1 undergoes tyrosine phosphorylation and binds SHP tyrosine phosphatases in response to growth factors, cytokines or integrin-mediated cell adhesion Tsuda et al., 1998;van Beek et al., 2005). SHP-1 and SHP-2 are thus thought to participate downstream of SHPS-1 in specific biological functions mediated by the CD47-SHPS-1 system.The CD47-SHPS-1 system participates in regulation of a variety of biological functions, particularly in the immune and nervous systems. The binding of CD47 on red blood cells to SHPS-1 on splenic macrophages is thought to prevent phagocytosis of the f...

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Aspergillus, a genus of filamentous fungi, is extensively distributed in nature and plays crucial roles in the decomposition of organic materials as an important environmental microorganism as well as in the traditional fermentation and food processing industries. Furthermore, due to their strong potential to secrete a large variety of hydrolytic enzymes and other natural products by manipulating gene expression and/or introducing new biosynthetic pathways, several Aspergillus species have been widely exploited as microbial cell factories. In recent years, with the development of next-generation genome sequencing technology and genetic engineering methods, the production and utilization of various homo-/heterologous-proteins and natural products in Aspergillus species have been well studied. As a newly developed genome editing technology, the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system has been used to edit and modify genes in Aspergilli. So far, the CRISPR/Cas9-based approach has been widely employed to improve the efficiency of gene modification in the strain type Aspergillus nidulans and other industrially important and pathogenic Aspergillus species, including Aspergillus oryzae, Aspergillus niger, and Aspergillus fumigatus. This review highlights the current development of CRISPR/Cas9-based genome editing technology and its application in basic research and the production of recombination proteins and natural products in the Aspergillus species.