Biochemical characterization of Rhodococcus erythropolis N′4 nitrile hydratase acting on 4-chloro-3-hydroxybutyronitrile

2008 ◽  
Vol 55 (3-4) ◽  
pp. 157-163 ◽  
Author(s):  
Yun Hee Choi ◽  
Ki-Nam Uhm ◽  
Hyung-Kwoun Kim
2001 ◽  
Vol 67 (2) ◽  
pp. 733-741 ◽  
Author(s):  
Cécile J. B van der Vlugt-Bergmans ◽  
Mariët J. van der Werf

ABSTRACT A monoterpene ɛ-lactone hydrolase (MLH) from Rhodococcus erythropolis DCL14, catalyzing the ring opening of lactones which are formed during degradation of several monocyclic monoterpenes, including carvone and menthol, was purified to apparent homogeneity. It is a monomeric enzyme of 31 kDa that is active with (4R)-4-isopropenyl-7-methyl-2-oxo-oxepanone and (6R)-6-isopropenyl-3-methyl-2-oxo-oxepanone, lactones derived from (4R)-dihydrocarvone, and 7-isopropyl-4-methyl-2-oxo-oxepanone, the lactone derived from menthone. Both enantiomers of 4-, 5-, 6-, and 7-methyl-2-oxo-oxepanone were converted at equal rates, suggesting that the enzyme is not stereoselective. Maximal enzyme activity was measured at pH 9.5 and 30°C. Determination of the N-terminal amino acid sequence of purified MLH enabled cloning of the corresponding gene by a combination of PCR and colony screening. The gene, designated mlhB(monoterpene lactone hydrolysis), showed up to 43% similarity to members of the GDXG family of lipolytic enzymes. Sequencing of the adjacent regions revealed two other open reading frames, one encoding a protein with similarity to the short-chain dehydrogenase reductase family and the second encoding a protein with similarity to acyl coenzyme A dehydrogenases. Both enzymes are possibly also involved in the monoterpene degradation pathways of this microorganism.


Certain microorganisms especially bacteria and fungi are able to use xenobiotic organic compounds as their carbon and nitrogen source for metabolism. Flower farms around lake Naivasha basin uses several agrochemicals especially pesticides to control pests and improve flower production. The aim of this study was to isolate and characterize morphologically and biochemically the main bacterial species that are able to grow and tolerate the pesticide contaminated farm soils. Soil samples were collected from randomly selected five greenhouses from each five flower farms namely Crescent, Elsamere, Karuturi, Malewa and Sewage farms around Lake Naivasha basin. The collected samples were processed for bacterial isolation using the nutrient agar, mac’ Conkey agar, blood agar, Luria-Bertani and Minimum Salt Media nutrient media. The conventional methods of swabbing and streaking were used. Pure colonies of isolates organisms were identified and characterized using standard microbiological technique. Morphological, cultural and biochemical characterization of bacterial species isolated from the flower farm soil samples identified mainly Pseudomonas auriginosa, Escherichia coli, Rhodococcus erythropolis and Bacillus subtilis species. Bacterial growth in pesticide consortia was quantified by monitoring colony growth of the species in liquid culture over time. The viable cell counts were determined turbidimetrically at O.D696nm. All the isolated bacterial species were able to grow in flower farm soil contaminated with organochloride and organophosphate pesticide residues. B. subtilis recorded the highest growth at 1.77±0.07 O.D696nm in pesticide mixture consortia. There was lower growth in organochloride pesticide consortia as compared to organophosphate pesticide consortia.


3 Biotech ◽  
2012 ◽  
Vol 3 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Ashwini L. Kamble ◽  
Linga Banoth ◽  
Vachan Singh Meena ◽  
Amit Singh ◽  
Yusuf Chisti ◽  
...  

Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.


2014 ◽  
Vol 3 (3) ◽  
pp. 218-225
Author(s):  
R. G. Somkuwar ◽  
M. A. Bhange ◽  
A. K. Upadhyay ◽  
S. D. Ramteke

SauvignonBlanc wine grape was characterized for their various morphological, physiological and biochemical parameters grafted on different rootstocks. Significant differences were recorded for all the parameters studied. The studies on vegetative parameters revealed that the rootstock influences the vegetative growth thereby increasing the photosynthetic activities of a vine. The highest photosynthesis rate was recorded in 140-Ru grafted vine followed by Fercal whereas the lowest in Salt Creek rootstock grafted vines.The rootstock influenced the changes in biochemical constituents in the grafted vine thereby helping the plant to store enough food material. Significant differences were recorded for total carbohydrates, proteins, total phenols and reducing sugar. The vines grafted on1103-Pshowed highest carbohydrates and starch followed by 140-Ru,while the least amount of carbohydrates were recorded in 110-R and Salt Creek grafted vines respectively.Among the different rootstock graft combinations, Fercal showed highest amount of reducing sugar, proteins and phenols, followed by 1103-P and SO4, however, the lowest amount of reducing sugar, proteins and phenols were recorded with 110-R grafted vines.The vines grafted on different rootstocks showed changes in nutrient uptake. Considering this, the physico-biochemical characterization of grafted vine may help to identify particularrootstocks combination that could influence a desired trait in commercial wine grape varieties after grafting.


Sign in / Sign up

Export Citation Format

Share Document