Extracellular peptidases from Deinococcus radiodurans

Abstract

The extremophile Deinococcus radiodurans wild type R1 produces peptidases (metallo- and serine-) in TGY medium and in the media supplemented with human hair (HMY) and chicken feathers (FMY). Enzymatic screening on agar plates revealed peptidase activity. In TGY medium metallopeptidases were detected corresponding to a molecular mass range of 300-85 kDa (gelatinases); 280-130 (caseinases) and a 300 and a 170 kDa (keratinases); and a gelatinolytic serine peptidase (75 kDa). In HMY medium after 144 h, D. radiodurans produced keratinase (290 U/ml), gelatinase (619 U/ml) and sulfite (26 µg/ml). TGY medium produced higher proteolytic activity: 950 U/ml of gelatinolytic (24 h); 470 U/ml of keratinolytic (24 h) and 110 U/ml of caseinolytic (72 h). In the FMY medium, we found gelatinolytic (317 U/ml), keratinolytic (43 U/ml) and caseinolytic (85 U/ml) activities. The sulfite had a maximum release at 48 h (8.1 µg/ml). Enzymography analysis revealed that the keratinases degraded keratin after 24 h of reaction. The addition of sodium sulfite (1.0 %) improved the keratin degradation. Environmental Scanning Electron microscopy revealed alterations such as damage and holes in the hair fiber cuticle after D. radiodurans growth. This work presents for the first time D. radiodurans as a new keratinolytic microorganism.

Identification, Characterization Enzymatic Antagonist Activity and Antimicrobial Resistance Profile of Bacteria Isolated From Brazilian Thermal Aquifer / Identificação, Caracterização Enzimática, Atividade Antagonista E Perfil De Resistência a Antimicrobianos De Bactérias Termotolerantes Isoladas Em Aquífero Termal Brasileiro

“…However, microbial proteases are among the most important hydrolytic enzymes with great potential for use in various biotechnological processes, as food processing, pharmaceutical products and several other industries (Uddin et al, 2017). Caseinase is used in the food industry as a coagulant in cheese manufacturing and in the reduction of milk allergens, as well as in the energy drinks, dietary foods and health care industry (Dalmaso et al, 2015;Bhaturiwala et al, 2017). Another important protease, gelatinase has played an important role in the food industry, as a meat tenderizer, in the beverage industry, cosmetics and in the development of drugs due to its ability to degrade connective tissue linked to tumor metastasis (Dalmaso et al, 2015;Mohammad et al, 2017).…”

“…Caseinase is used in the food industry as a coagulant in cheese manufacturing and in the reduction of milk allergens, as well as in the energy drinks, dietary foods and health care industry (Dalmaso et al, 2015;Bhaturiwala et al, 2017). Another important protease, gelatinase has played an important role in the food industry, as a meat tenderizer, in the beverage industry, cosmetics and in the development of drugs due to its ability to degrade connective tissue linked to tumor metastasis (Dalmaso et al, 2015;Mohammad et al, 2017). In the diffusion disc antimicrobial susceptibility test, the isolates were sensitive to all antibiotics tested (Table 3), and the results corroborates that microorganisms in natural environments are presumably sensitive to antibiotics (Grenni et al, 2018) and a study performed by Selim et al (2014) in which microorganisms isolated from water and hot spring soils were sensitive to all antibiotics tested.…”

Molecular Identification of Keratinase DgokerA from Deinococcus gobiensis for Feather Degradation

“…Extremophiles are considered a valuable source for the production of novel enzymes due to their unique metabolism and ability to withstand extreme environments, such as high temperature, high pressure, high pH and high radiation [13][14][15]. Many studies have been conducted to identify keratinases with excellent properties from extremophiles, such as Nocardiopsis [16], Salicola Marasensis [17] and Meiothermus taiwanensis WR-220 [7].…”

“…M. taiwanensis WR-220 was a thermophilic microorganism with a growth temperature of 55-65 • C. The keratinase from this bacterium also exhibited thermal stability, maintaining intact enzymatic activity after 1 h of treatment at 75 • C [7]. It was shown that keratinase genes are present in extreme microorganisms Deinococcus [14], such as D. geothermalis [18] and Deinococcus sp. D7000 [19], and that the feather-degrading bacteria D. ficus [20] and D. radiodurans R1 [14] are able at 30 • C to degrade intact feathers.…”

“…It was shown that keratinase genes are present in extreme microorganisms Deinococcus [14], such as D. geothermalis [18] and Deinococcus sp. D7000 [19], and that the feather-degrading bacteria D. ficus [20] and D. radiodurans R1 [14] are able at 30 • C to degrade intact feathers.…”