Bacillus immobilization

Pure Ti02 was recently reported to be active in the disinfection of water contaminated by spores of the type Fusarium solani [142], Bacillus anthracis [143], or Cryptosporidium parvum oocysts [144], or when supported as nanocomposites on zeolite H(i for E. coli deactivation [145], and it found applications in water treatment as a replacement for chlorine. Ag-Ti02 immobilized systems were used for inactivation of bacteria, coupling the visible light response of the system and the strong bactericidal effect of Ag [146]. Silver was deposited on hydroxyapatite to form nanocomposites with a high capacity for bacterial adsorption and inactivation [147], or used for airborne bacterial remediation in indoor air [148],... 

D-4-Hydroxyphenyl glycine 9 Ampicillin/ amoxycillin Antibacterial Hydrolysis Bacillus brevis Immobilized cells [8]... 

A strain of yeast and a strain of bacterium were co-immobilized to fabricate a biochemical oxygen demand (BOD) sensor based on sol-gel derived composite materials97. This novel type of biosensor was developed for water monitoring and was used to determine the BOD values of OECD synthetic wastewater, domestic wastewater, and lake waters. The microorganisms Trichosporon cutaneum and Bacillus subtilis were coimmobilized in the sol-gel composite material, which was composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). 

The sol-gel-entrapped microbial cells have shown excellent tolerance to different alcohols [99], The immobilized E. coli cells followed the Michaelis-Menten equation when quantified with the (3-glucosidase activity via the hydrolysis of 4-nitrophenyl-(3-D-galactopyranosdie [142], The sol-gel matrices doped with gelatin prevented the cell lysis, which usually occurs during the initial gelation process [143], Microorganisms are now widely used in the biosorption of different pollutants and toxicants. Bacillus sphaericus JG-A12 isolated from uranium mining water has been entrapped in aqueous silica nanosol for the accumulation of copper and uranium [144], Premkumar et al. [145] immobilized recombinant luminous bacteria into TEOS sol-gel to study the effect of sol-gel conditions on the cell response (luminescence). The entrapped and free cells showed almost the same intensity of luminescence (little lower), but the entrapped cells were more stable than the free cells (4 weeks at 4°C). This kind of stable cell could be employed in biosensors in the near future. 

Some recent approaches to orientated immobilization exploited methods of genetic engineering to introduce suitable binding site like a cysteine residue [101]. Mansfeld and Ulbrich-Hofmann introduced cysteine on a thermolysinelike neutral protease from Bacillus stearothermophilus [114]. This approach is especially interesting since it allows the introduction of cystein residues in different positions of the protein molecule and therefore enables one to study the effects of molecule orientation on its biological activity [115]. More information about the oriented immobilization can be found in recent reviews of Turkova [101,110]. 

Since these early discoveries, xylose isomerases have been isolated from many bacterial species, and these enzymes have been intense investigated, especially those of the genera Streptomyces, Lactobacillus, and Bacillus. The characteristics of substrate specificity (xylose glucose > ribose), divalent metal cation activation (Mg, Mn or Co ), and activity at alkaline pH are properties that most of the enzymes share to a certain extent, but significant variations exist. Some of these em es have been immobilized and patented for commercial use. There are many good reviews in the literature that describe the enzymatic characteristics of the xylose isomerases 9,28,29). 

Vassileva, A., Burhan, N., Beschkov, V. et al.. Cyclodextrin glucanotransferase production by free and agar gel immobilized cells of Bacillus circulans ATCC 21783, Process Biochem., 38 (2003) 1585-1591. 

Bakken, A.P., Hill, C.G. and Amnndson, C.H. (1992) Hydrolysis of Lactose in Skim Milk by Immobilized Beta Galactosidase Bacillus-Circulans. Biotechnology and Bioengineering, 39, 408-417. 

Esterases are much less tolerant of anhydrous media than lipases. The esterases from Bacillus stearothermophilus (BstE) and Bacillus subtilis (BsE) are exceptional, as these mediated transesterification in hexane at aw=0.1 [66]. Both esterases, if immobilized on Celite 560, mediated transesterification in [BMIm][BF4], [BMIm][PF6], and [BMIm][ Tf2N] at a rate that varied from 20 to 60% of the rate in hexane or ME. 

Walker, S. G., Flemming, C.A., Ferris, F.G., Beveridge, T.J. Bailey, G. W. (1989). Physiochemical interaction of Escherichia coli cell envelopes and Bacillus subtilis cell walls with two clays and ability of the composite to immobilize heavy metals from solution. Applied and Environmental Microbiology, 55, 2976-84. 

L. Ferreira, M. A. Ramos, M. H. Gil, and J. S. Dordick, Exquisite regioselectivity and increased transesterification activity of an immobilized Bacillus subtilis protease, Biotechnol. Prog. (2002) 986-993. 

Considerable effort based on research work initiated in the 1950s resulted in enzyme technology able to convert glucose to fructose on a commercial scale.32 34 Current production of high-fructose syrups generally uses immobilized, rather than soluble, enzymes. Sources of the enzyme include Streptomyces, Bacillus, Actinoplanes and Arthrobacter species. 

The bioconversion of hydrocortisone to prednisolone by free, immobilized, and reused immobilized cells of Bacillus sphaericus ATCC 13805, B. sphaericus SRP III, and Arthrobacter simplex 6946 was investigated in an aqueous as well as a two-liquid-phase system using various organic solvents [141]. The immobilized cells... 

The most widely used immobilized enzyme process involves the use of the enzyme glucose isomerase for the conversion of glucose to fructose in com syrup (Carasik and Carroll 1983). The organism Bacillus coagu-lans has been selected for the production of glucose isomerase. The development of the immobilized cell slurry has not proceeded to the point where half-lives of the enzyme are more than 75 days. A half-life is defined as the time taken for a 50 percent decrease in activity. Such immobilized enzyme columns can be operated for periods of over three half-lives. 

Chen, J., Zheng, Y.G., and Shen, Y.C. 2008. Biosynthesis of p-methoxyphenylacetic acid from p-methoxyacetonitrile by immobilized Bacillus subtilis ZJB-063. Process Biochemistry, 43 978-83. 

Graham, D., Pereira, R.A., Barfield, D., and Cowan, D.A. 2000. Nitrile biotransformations using free and immobilized cells of a thermophilic Bacillus spp. Enzyme Microbiology and Technology, 26 368-73. 

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