The gene encoding an extracellular α-amylase from Bacillus subtilis DR8806 was cloned into pET28a(+) vector and expressed in Escherichia coli BL21 (DE3). The recombinant enzyme with molecular mass of 76 kDa exhibited optimal activity at pH 5.0 and 70 °C with high stability in pH and temperature ranges of 4.0-9.0 and 45-75 °C. The enzyme showed a half-life of 125 min at 70 °C. The α-amylase activity enhanced in the presence of Na(+), K(+), and Ca(2+) ions, while Zn(2+), Pb(2+), and Hg(2+) ions inhibited the activity. The recombinant α-amylase exhibited high stability towards ioninc detergents sodium dodecyl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Organic solvents in reaction media increased the α-amylase activity. TLC analysis showed that maltoriose and maltose were the major end products of enzymatic starch hydrolysis. Presenting various properties of recombinant α-amylase makes it well suited as a potential candidate for industrial usages.
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http://dx.doi.org/10.1016/j.ijbiomac.2014.08.023 | DOI Listing |
Microlife
January 2025
DTU Bioengineering, Technical University of Denmark, 2800 Kgs Lyngby, Denmark.
Although not essential for their growth, the production of secondary metabolites increases the fitness of the producing microorganisms in their natural habitat by enhancing establishment, competition, and nutrient acquisition. The Gram-positive soil-dwelling bacterium, , produces a variety of secondary metabolites. Here, we investigated the regulatory relationship between the non-ribosomal peptide surfactin and the sactipeptide bacteriocin subtilosin A.
View Article and Find Full Text PDFBiofilm
June 2025
DTU Bioengineering, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
Surfactin is a biosurfactant produced by many strains with a wide variety of functions from lowering surface tension to allowing motility of bacterial swarms, acting as a signaling molecule, and even exhibiting antimicrobial activities. However, the impact of surfactin during biofilm formation has been debated with variable findings between studies depending on the experimental conditions. B.
View Article and Find Full Text PDFJ Microbiol Biotechnol
December 2024
School of Biotechnology and Key Laboratory of Industrial Biotechnology Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, P.R. China.
Gamma-aminobutyric acid (GABA), a non-proteinogenic amino acid, exhibits diverse physiological functions and finds extensive applications in food, medicine, and various industries. Glutamate decarboxylase (GAD) can effectively convert L-glutamic acid (L-Glu) or monosodium glutamate (MSG) into GABA. However, the low food-grade expression of GAD has hindered large-scale GABA production.
View Article and Find Full Text PDFFood Res Int
February 2025
School of Food Engineering and Nutrition Science, Shaanxi Normal University, Xi'an 710119, China. Electronic address:
In order to investigate the effect of apricot kernels on microbial community composition during Massa Medicata Fermentata (MMF) fermentation and to preliminarily explore whether it is related to amygdalin. In this paper, the structural characteristics of MMF and the composition of its bacterial and fungal communities during fermentation were determined. The results showed that both microscopy and infrared techniques could identify the structure of the apricot kernel in MMF and whether the kernel had been debitterized or not; the dominant bacterial phyla in MMF were Firmicutes and Proteobacteria, with the dominant bacterial genera being Staphylococcus and Bacillus, and the dominant fungal phylum was Ascomycota, with the dominant fungal genus being Aspergillus.
View Article and Find Full Text PDFFood Res Int
February 2025
Department of Veterinary Medicine, Zhejiang University College of Animal Sciences, Hangzhou 310058, China; Hainan Institute of Zhejiang University, Sanya 310058, China. Electronic address:
Bacillus cereus is a common pathogen responsible for gastrointestinal and other complicated disorders, yet epidemiological data and public health measures remain scarce. To bridge these gaps, a bilingual search spaning 50 years identified 266 relevant studies on global B. cereus infection, encompassing 6,135 cases.
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