scholarly journals Preparation and characterization of substrates suitable for the study of stereospecific secondary alkylsulphohydrolases of detergent-degrading micro-organisms

1977 ◽  
Vol 167 (3) ◽  
pp. 717-722 ◽  
Author(s):  
G W J Matcham ◽  
K S Dodgson
Keyword(s):  
Alkyl Chain ◽  
Secondary Alcohols ◽  
Sulphate Group ◽  
Initial Information ◽  
Micro Organisms ◽  
Comamonas Terrigena

During the course of the purification of novel stereospecific secondary aklylsulphohydrolases present in certain detergent-degrading micro-organisms, it became apparent that substrates prepared by sulphating secondary alcohols with H2SO4 are heterogeneous. Apart from the racemization that occurs if resolved alcohols are sulphated, evidence is provided to show that other isomers are produced in which the position of the ester sulphate group on the alkyl chain has been altered. These changes can be avoided if pyridine/SO3 reagent (prepared with SO3) is substituted as sulphating agent. Experiments in which secondary alkyl sulphates prepared by both methods were tested as potential substrates for the two secondary alkylsulphohydrolase enzymes of Comamonas terrigena have provided initial information about the specificity of the enzymes.

scholarly journals Purification and properties of the S1 secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B

1978 ◽  
Vol 169 (3) ◽  
pp. 659-667 ◽  
Author(s):  
Barbara Bartholomew ◽  
Kenneth S. Dodgson ◽  
Stephen D. Gorham
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Competitive Inhibitor ◽  
Sulphate Group ◽  
Experimental Conditions ◽  
Alkyl Sulphate ◽  
Purification And Properties ◽  
Crude Preparation ◽  
A Chain ◽  
Comamonas Terrigena

The S1 secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B, was separated from other alkylsulphohydrolases and purified to homogeneity. Under the experimental conditions used the enzyme completely hydrolysed d-octan-2-yl sulphate (d-1-methylheptyl sulphate), but showed no activity towards the corresponding l-isomer. Additional evidence has been obtained to indicate that it is probably optically stereospecific for d-secondary alkyl sulphate esters with the ester sulphate group at C-2 and with a chain length of at least seven carbon atoms. Enzyme activity towards racemic samples of heptan-2-yl sulphate (1-methylhexyl sulphate), octan-2-yl sulphate and decan-2-yl sulphate (1-methylnonyl sulphate) increased with increasing chain length. l-Octan-2-yl sulphate is a competitive inhibitor of the enzyme, as are certain primary alkyl sulphates and primary alkanesulphonates. Inhibition by each of the last two types of compounds is characteristic of the behaviour of an homologous series. Inhibition increases with increasing chain length and plots of log Ki values against the number of carbon atoms in each alkyl chain show the expected linear relationship. A crude preparation of the S2 secondary alkylsulphohydrolase was used to show that this particular enzyme hydrolyses l-octan-2-yl sulphate, but is probably inactive towards the corresponding d-isomer. The similarity of the S1 and S2 enzymes to the CS2 and CS1 enzymes respectively of Comamonas terrigena was established, and some comments have been made on the possible roles of these and other alkylsulphohydrolases in the biodegradation of detergents.

scholarly journals Synthesis and Characterization of Series of Methoxy-Substituted Salamo-Type Compounds Having More Flexible O-Alkyl Chain

2014 ◽  
Vol 26 (20) ◽  
pp. 6918-6920 ◽  
Author(s):  
Xiu-Yan Dong ◽  
Su-Xia Gao ◽  
Yu-Jie Zhang ◽  
Yang Zhang ◽  
Li Wang
Keyword(s):  
Alkyl Chain ◽  
Synthesis And Characterization

Biochemical and taxonomic characterization of bacteria associated with the crucifer root maggot (Delia radicum)

2006 ◽  
Vol 52 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Angelina T Lukwinski ◽  
Janet E Hill ◽  
George G Khachatourians ◽  
Sean M Hemmingsen ◽  
Dwayne D Hegedus
Keyword(s):  
Hydrolytic Enzymes ◽  
Delia Radicum ◽  
Culturable Bacteria ◽  
Carbohydrate Utilization ◽  
Important Pest ◽  
Host Nutrition ◽  
Utilization Patterns ◽  
Root Maggot ◽  
Micro Organisms

The crucifer root maggot, Delia radicum, is an important pest of cruciferous crops; however, little is known about its digestive biochemistry or resident gut microbiota. A culturing approach was used to survey the types of micro organisms associated with eggs, midgut, and faeces of larvae feeding on rutabaga. All bacteria isolated from the midgut and faecal materials were Gram-negative bacilli. Nine types of culturable bacteria were identified within the midgut based on analysis of 60 kDa chaperonin sequences and were generally γ-Proteobacteria, primarily Enterobacteriaceae. Carbohydrate utilization patterns, select biochemical pathways, and hydrolytic enzymes were examined using the API®system for each of the nine groups, revealing an exceptionally broad metabolic and hydrolytic potential. These studies suggest that resident alimentary tract microorganisms have the potential to contribute to host nutrition directly as a food source as well as by providing increased digestive potential.Key words: Delia radicum, crucifer root maggot, midgut-associated bacteria.

scholarly journals About the dangers, costs and benefits of living an aerobic lifestyle

2014 ◽  
Vol 42 (4) ◽  
pp. 917-921 ◽  
Author(s):  
Daniela Knoefler ◽  
Lars I.O. Leichert ◽  
Maike Thamsen ◽  
Claudia M. Cremers ◽  
Dana Reichmann ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Research Programme ◽  
Future Research ◽  
Mammalian Host ◽  
Costs And Benefits ◽  
Cellular Processes ◽  
Effective Antioxidant ◽  
Development And Differentiation ◽  
Micro Organisms

The era in which ROS (reactive oxygen species) were simply the ‘bad boys of biology’ is clearly over. High levels of ROS are still rightfully considered to be toxic to many cellular processes and, as such, contribute to disease conditions and cell death. However, the high toxicity of ROS is also extremely beneficial, particularly as it is used to kill invading micro-organisms during mammalian host defence. Moreover, a transient, often more localized, increase in ROS levels appears to play a major role in signal transduction processes and positively affects cell growth, development and differentiation. At the heart of all these processes are redox-regulated proteins, which use oxidation-sensitive cysteine residues to control their function and by extension the function of the pathways that they are part of. Our work has contributed to changing the view about ROS through: (i) our characterization of Hsp33 (heat-shock protein 33), one of the first redox-regulated proteins identified, whose function is specifically activated by ROS, (ii) the development of quantitative tools that reveal extensive redox-sensitive processes in bacteria and eukaryotes, and (iii) the discovery of a link between early exposure to oxidants and aging. Our future research programme aims to generate an integrated and system-wide view of the beneficial and deleterious effects of ROS with the central goal to develop more effective antioxidant strategies and more powerful antimicrobial agents.

scholarly journals A novel mechanism of enzymic ester hydrolysis. Inversion of configuration and carbon-oxygen bond cleavage by secondary alkylsulphohydrolases from detergent-degrading micro-organisms

1977 ◽  
Vol 165 (3) ◽  
pp. 575-580 ◽  
Author(s):  
B Bartholomew ◽  
K S Dodgson ◽  
G W J Matcham ◽  
D J Shaw ◽  
G F White
Keyword(s):  
Bond Cleavage ◽  
Hydrolytic Enzymes ◽  
Ester Hydrolysis ◽  
Enzymic Hydrolysis ◽  
Hydrolysis Products ◽  
Bond Scission ◽  
Micro Organisms ◽  
Hydrolysis Of ◽  
Oxygen Bond ◽  
Comamonas Terrigena

The hydrolysis was studied of potassium (+)-octan-2-yl sulphate by two analogous, optically stereospecific, secondary alkylsulphohydrolases purified from two detergent-degrading micro-organisms, Comamonas terrigena and Pseudomonas C12B. Polarimetry studies have shown that (+)-octan-2-yl sulphate prepared from (+)-octan-2-ol is hydrolysed by both enzymes to yield (-)-octan-2-ol. This inversion of configuration implies that the enzymes are catalysing the scission of the C-O bond of the C-O-S linkage, a type of bond scission apparently not hitherto encountered among hydrolytic enzymes acting on ester bonds. Enzymic hydrolysis of potassium (+)-octan-2-yl sulphate in the presence of H218O and analysis of hydrolysis products for the presence of 18O has confirmed that C-O bond scission (and not O-S bond scission) occurs with both enzymes.

scholarly journals A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

2009 ◽  
Vol 5 ◽  
Author(s):  
Andrew Bogdan ◽  
D Tyler McQuade
Keyword(s):  
Packed Bed ◽  
Secondary Alcohols ◽  
Great Stability ◽  
Wide Range ◽  
Oxidation Of Alcohols ◽  
Aldehydes And Ketones ◽  
High Yields ◽  
By Products ◽  
Over Time

We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leaving the organic product separate from the aqueous by-products. Furthermore, the microreactor oxidized a wide range of alcohols and remained active in excess of 100 trials without showing any loss of catalytic activity.

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