Identification and characterization of inulinases by bioinformatics analysis of bacterial glycoside hydrolases family 32 (GH32)

Abstract

The glycoside hydrolase family contains enzymes that break the glycosidic bonds of carbohydrates by hydrolysis. Inulinase is one of the most important industrial enzymes in the family of Glycoside Hydrolases 32 (GH32). In this study, to identify and classify bacterial inulinases initially, 16,002 protein sequences belonging to the GH32 family were obtained using various databases. The inulin-effective enzymes (endoinulinase and exoinulinase) were identified. Eight endoinulinases (EC 3.2.1.7) and 4318 exoinulinases (EC 3.2.1.80) were found. Then, the localization of endoinulinase and exoinulinase enzymes in the cell was predicted. Among them, two extracellular endoinulinases and 1232 extracellular exoinulinases were found. The biochemical properties of 363 enzymes of the genus Arthrobacter, Bacillus, and Streptomyces (most abundant) showed that exoinulinases have an acid isoelectric point up to the neutral range due to their amino acid length. That is, the smaller the protein (336 aa), the more acidic the pI (4.39), and the larger the protein (1207 aa), the pI is in the neutral range (8.84). Also, a negative gravitational index indicates the hydrophilicity of exoinulinases. Finally, considering the biochemical properties affecting protein stability and post-translational changes studies, one enzyme for endoinulinase and 40 enzymes with desirable characteristics were selected to identify their enzyme production sources. To screen and isolate enzyme-containing strains, now with the expansion of databases and the development of bioinformatics tools, it is possible to classify, review and analyze a lot of data related to different enzymeproducing strains. Although, in laboratory studies, a maximum of 20 to 30 strains can be examined. Therefore, when more strains are examined, finally, strains with more stable and efficient enzymes were selected and introduced for laboratory activities. The findings of this study can help researchers to select the Abbreviation: GH32, Glycoside Hydrolase 32.

Genome Characteristics of the Endophytic Fungus Talaromyces sp. DC2 Isolated from Catharanthus roseus (L.) G. Don

“…It consists of glucose molecules at the terminal end [46]. The process of inulin conversion involves the utilization of the glycosyl hydrolase families GH32 and GH91, which include enzymes such as inulinase, invertase, levanase, 1-exohydrolases, fructanfructosyltransferases, and sucrose fructosyltransferases [47]. The genome of strain DC2 contained five genes encoding endo-inulinase from the GH32 family, which is consistent with the discovery made in Apgergillus niger [48].…”

Characterization of exo-inulinase from endophytic Rossellomorea aquimaris3.13 for inulin digestion of Jerusalem artichoke tubers

“…Inulinases have been reported in fungi, yeast and bacteria; microorganisms are commonly applied for commercial productions of enzymes which require quick, easy processes and high yields. The reports of Bacillus genus produced inulinase showed in B. cereus MU-31 (66 kDa), B. smithii T7 (47 kDa), B. stearothermophilus KP 1289 (54 kDa) (Meenakshi et al 2013;Gao et al 2009;Keto et al 1999); the molecular mass of inulinase had been reported between 37-134 kDa (Khosravi et al 2023), e.g. Bacillus salsus (37 kDa) and Bacillus sp.…”

Production and statistical optimization of invertase-free exoinulinase from Glutamicibacter arilaitensis using goat dung as ideal feedstock

“…It is an industrially important versatile enzyme, which is known to produce inulo-oligosaccharides, fructose, and glucose as decisive products by acting on β-2,1 linkages of inulin (Rawat et al 2016). Based on the biocatalytic mechanism of action, exoinulinases (EC 3.2.1.8; β-2-1-D-fructan fructohydrolase) are in one of the most substantial categories of inulinase; they are known to remove the terminal fructose residues from the non-reducing end of inulin Khosravi et al 2023). In general, inulin is a foremost storage carbohydrate after starch in 36000 species of plants (Chi et al 2011).…”