Enhanced enantioselectivity of Bacillus coagulans in the hydrolysis of 1,2-O-isopropylidene glycerol esters by thermal knock-out of undesired enzymes

2005 ◽  
Vol 16 (4) ◽  
pp. 841-845 ◽  
Author(s):  
Diego Romano ◽  
Francesco Falcioni ◽  
Diego Mora ◽  
Francesco Molinari ◽  
Andreas Buthe ◽  
...  
Keyword(s):  
Bacillus Coagulans ◽  
Knock Out ◽  
Isopropylidene Glycerol ◽  
Hydrolysis Of

scholarly journals MutT homologue 1 (MTH1) removes N6-methyl-dATP from the dNTP pool

2020 ◽  
Vol 295 (15) ◽  
pp. 4761-4772 ◽  
Author(s):  
Emma Rose Scaletti ◽  
Karl S. Vallin ◽  
Lars Bräutigam ◽  
Antonio Sarno ◽  
Ulrika Warpman Berglund ◽  
...  
Keyword(s):  
Efficient Catalyst ◽  
Knock Out ◽  
Dntp Pool ◽  
Mrna Metabolism ◽  
Methylation Of Dna ◽  
Dna And Rna ◽  
Nudix Hydrolases ◽  
Protein Isoform ◽  
Hydrolysis Of

MutT homologue 1 (MTH1) removes oxidized nucleotides from the nucleotide pool and thereby prevents their incorporation into the genome and thereby reduces genotoxicity. We previously reported that MTH1 is an efficient catalyst of O6-methyl-dGTP hydrolysis suggesting that MTH1 may also sanitize the nucleotide pool from other methylated nucleotides. We here show that MTH1 efficiently catalyzes the hydrolysis of N6-methyl-dATP to N6-methyl-dAMP and further report that N6-methylation of dATP drastically increases the MTH1 activity. We also observed MTH1 activity with N6-methyl-ATP, albeit at a lower level. We show that N6-methyl-dATP is incorporated into DNA in vivo, as indicated by increased N6-methyl-dA DNA levels in embryos developed from MTH1 knock-out zebrafish eggs microinjected with N6-methyl-dATP compared with noninjected embryos. N6-methyl-dATP activity is present in MTH1 homologues from distantly related vertebrates, suggesting evolutionary conservation and indicating that this activity is important. Of note, N6-methyl-dATP activity is unique to MTH1 among related NUDIX hydrolases. Moreover, we present the structure of N6-methyl-dAMP–bound human MTH1, revealing that the N6-methyl group is accommodated within a hydrophobic active-site subpocket explaining why N6-methyl-dATP is a good MTH1 substrate. N6-methylation of DNA and RNA has been reported to have epigenetic roles and to affect mRNA metabolism. We propose that MTH1 acts in concert with adenosine deaminase-like protein isoform 1 (ADAL1) to prevent incorporation of N6-methyl-(d)ATP into DNA and RNA. This would hinder potential dysregulation of epigenetic control and RNA metabolism via conversion of N6-methyl-(d)ATP to N6-methyl-(d)AMP, followed by ADAL1-catalyzed deamination producing (d)IMP that can enter the nucleotide salvage pathway.

scholarly journals Integration of Solid State and Submerged Fermentations for the Valorization of Organic Municipal Solid Waste

2021 ◽  
Vol 7 (9) ◽  
pp. 766
Author(s):  
Gheorghe-Adrian Martău ◽  
Peter Unger ◽  
Roland Schneider ◽  
Joachim Venus ◽  
Dan Cristian Vodnar ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Solid State ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bacillus Coagulans ◽  
Aspergillus Awamori ◽  
Organic Residues ◽  
Organic Fraction ◽  
Hydrolysis Of ◽  
Suitable Process

Solid state fermentation (SsF) is recognized as a suitable process for the production of enzymes using organic residues as substrates. However, only a few studies have integrated an evaluation of the feasibility of applying enzymes produced by SsF into subsequent hydrolyses followed by the production of target compounds, e.g., lactic acid (LA), through submerged-liquid fermentations (SmF). In this study, wheat bran (WB) was used as the substrate for the production of enzymes via SsF by Aspergillus awamori DSM No. 63272. Following optimization, cellulase and glucoamylase activities were 73.63 ± 5.47 FPU/gds and 107.10 ± 2.63 U/gdb after 7 days and 5 days of fermentation, respectively. Enzymes were then used for the hydrolysis of the organic fraction of municipal solid waste (OFMSW). During hydrolysis, glucose increased considerably with a final value of 19.77 ± 1.56 g/L. Subsequently, hydrolysates were fermented in SmF by Bacillus coagulans A166 increasing the LA concentration by 15.59 g/L. The data reported in this study provides an example of how SsF and SmF technologies can be combined for the valorization of WB and OFMSW.

LIPASE AND ACETYL ESTERASE ACTIVITIES IN INTACT BACILLUS COAGULANS SPORES

1966 ◽  
Vol 44 (6) ◽  
pp. 677-685 ◽  
Author(s):  
Thomas L. Roberts ◽  
Harris Rosenkrantz
Keyword(s):  
Ethyl Acetate ◽  
Ultraviolet Light ◽  
Copper Acetate ◽  
Bacillus Coagulans ◽  
Fluorescein Diacetate ◽  
Ethyl Butyrate ◽  
Acetyl Esterase ◽  
Enzyme Substrates ◽  
Hydrolysis Of ◽  
Esterase Activities

Since data on esterase content of intact dormant spores are meager, a study was carried out with various enzyme substrates and several methods of product detection on intact and ruptured preparations of Bacillus coagulans. Measurement of hydrolysis of triacetin, naphthyl acetates, fluorescein diacetate, ethyl acetate, and ethyl butyrate demonstrated the presence of arylesterase, carboxylesterase, acetyl esterase, and lipase activities in both the intact and ruptured preparations of the non-germinated organism used. It was observed that spore esterase was inhibited by normal and basic copper acetate, eserine, taurocholate, 253.7 mμ ultraviolet light, and temperatures between 50 and 100 °C.

THE ASPARAGINE DEAMIDASE OF BACILLUS COAGULANS AND BACILLUS STEAROTHERMOPHILUS

1957 ◽  
Vol 3 (7) ◽  
pp. 1001-1009 ◽  
Author(s):  
Gilbert B. Manning ◽  
L. Leon Campbell Jr.
Keyword(s):  
Enzyme Activity ◽  
Bacillus Stearothermophilus ◽  
Bacillus Coagulans ◽  
Heat Stability ◽  
Transfer Reactions ◽  
Thermophilic Microorganisms ◽  
Enzyme Systems ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Inhibition Reaction

The purification and certain properties of L-asparagine deamidase of Bacillus coagulans and Bacillus stearothermophilus are described. Maximum enzyme activity was obtained at 55 °C. over a pH range of 7.5 to 8.5. The purified deamidase hyclrolyzed the L-isomer of asparagine quantitatively to aspartic acid and ammonia and did not attack the D-isomer. D-Asparagine inhibited the hydrolysis of the L-isomer. The Kmfor the inhibition reaction was found to be 1.87 × 10−2 M. The enzyme did not catalyze transamidation or hydroxylamine transfer reactions. Enzyme activity was inhibited by N-ethylmaleimide and p-chloromercuribenzoate. The inhibition by these agents was reversed by glutathione. In the absence of substrate the deamidase of both organisms was relatively heat labile at 55 °C. The heat lability of this enzyme is discussed in relation to the heat stability of other enzyme systems of thermophilic microorganisms.

Newly isolated Streptomyces spp. as enantioselective biocatalysts: hydrolysis of 1,2-O-isopropylidene glycerol racemic esters

2005 ◽  
Vol 99 (4) ◽  
pp. 960-967 ◽  
Author(s):  
F. Molinari ◽  
D. Romano ◽  
R. Gandolfi ◽  
R.M. Kroppenstedt ◽  
F. Marinelli
Keyword(s):  
Streptomyces Spp ◽  
Isopropylidene Glycerol ◽  
Hydrolysis Of

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Lattice imaging and pore structure of β ferric oxyhydroxide

1978 ◽  
Vol 36 (1) ◽  
pp. 264-265
Author(s):  
T. Baird ◽  
J.R. Fryer ◽  
S.T. Galbraith
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bulk Material ◽  
Model Structure ◽  
Bulk Crystals ◽  
Lattice Imaging ◽  
Thin Sections ◽  
Ferric Oxyhydroxide ◽  
Resolution Electron ◽  
Hydrolysis Of

Introduction Previously we had suggested (l) that the striations observed in the pod shaped crystals of β FeOOH were an artefact of imaging in the electron microscope. Contrary to this adsorption measurements on bulk material had indicated the presence of some porosity and Gallagher (2) had proposed a model structure - based on the hollandite structure - showing the hollandite rods forming the sides of 30Å pores running the length of the crystal. Low resolution electron microscopy by Watson (3) on sectioned crystals embedded in methylmethacrylate had tended to support the existence of such pores.We have applied modern high resolution techniques to the bulk crystals and thin sections of them without confirming these earlier postulatesExperimental β FeOOH was prepared by room temperature hydrolysis of 0.01M solutions of FeCl3.6H2O, The precipitate was washed, dried in air, and embedded in Scandiplast resin. The sections were out on an LKB III Ultramicrotome to a thickness of about 500Å.

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