scholarly journals pH and Temperature Dependent Gut Enzyme Niche in a Stomachless Herbivorous Freshwater Fish Amblypharyngodon mola (Hamilton, 1822)

2020 ◽  
Vol 12 (4) ◽  
pp. 729-741
Author(s):  
S. Debnath ◽  
S. I. Maiti ◽  
S. K. Saikia

The activities of digestive α-amylase (E. C. 3.2.1.1), total proteases, and bile salt-activated lipase (E. C. 3.1.1.-) along the digestive tract (lengthwise divided into five equal parts) of a stomachless freshwater fish (n = 10, weight = 4.354±0.316 g, standard length = 21.641±2.271 cm) were measured at different pH and temperature levels. Different optimum pH and temperature for the activity of α-amylase (8-9, 35°C), proteases (7-8, 45°C), and lipase (8, 45°C) were observed. The first two regions of the digestive tract showed comparatively higher activity of all enzymes. The hierarchical clustering technique revealed three different enzymatically active regions, more inclined to pH in the digestive tract of the studied fish. The present study also supports that the stomachless gut of A. mola has substantial resemblances to the intestinal part of the digestive tract of fish.

2021 ◽  
Vol 64 (2) ◽  
pp. 173-179
Author(s):  
Sanjeet Debnath ◽  
Surjya Kumar Saikia

Two teleosts (Rohu, Labeo rohita and Koi, Anabas testudineus), both with contrasting feeding habits (herbivorous versus carnivorous) were studied for amylase and protease activity concerning different regions of their digestive tracts. Significant differences in enzymatic activity across different regions of the digestive tracts were observed. Rohu, with three equal regions of the stomachless gut, showed the highest amylolytic activity at the posterior digestive tract but the highest proteolytic activity is limited to mid region. Contrary to such observation, Koi with three distinct regions of the digestive tract (stomach, pyloric caeca and intestine), the pyloric caeca exhibited the highest specific activity for both amylase and total protease. The optimum pH and temperature conditions were determined concerning the activity for both amylase and protease.


Author(s):  
Grace Madanire-Moyo ◽  
Annemariè Avenant-Oldewage

Cestodes are parasitic flatworms that live in the digestive tract of vertebrates as adults and often in the liver, muscle, haemocoel, mesentery and brain of various animals as larval stages. To identify the cestodes infecting Clarias gariepinus Burchell, 1822 (sharptooth catfish) in the Vaal Dam, a total of 45 host specimens were collected with the aid of gill nets between October 2011, January and April 2012. The fish were sacrificed and examined for cestode parasites. Two adult cestodes, Tetracampos ciliotheca Wedl, 1861 (prevalence 86.7%, mean intensity = 15, n = 45) and Proteocephalus glanduligerus (Janicki, 1928) (prevalence 51.1%, mean intensity = 5, n = 45) were found in the intestines of the catfish. Both T. ciliotheca and P. glanduligerus are new locality records. There were statistically insignificant differences in the infection of the male and female C. gariepinu. Fish with standard length ranging from 40 cm – 54 cm (≥ 3 years) had the highest prevalence and mean intensity while those ranging from 10 cm – 24 cm (< 1 year) had the lowest prevalence and mean intensity for both cestodes. The study highlights the importance of changing feeding habits of C. gariepinus with age on the prevalence and mean intensity of the two gastrointestinal cestode parasites.


2003 ◽  
Vol 46 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Gargi Dey ◽  
Singh Bhupinder ◽  
Rintu Banerjee

A maltooligosaccharide-forming amylase from B circulans GRS 313 was immobilized by entrapment in calcium alginate beads. The immobilized activity was affected by the size of the bead and bead size of 2mm was found to be most effective for hydrolysis. Kinetics constants, Km and Vmax were estimated and were found to be affected by the bead size. The catalytic activity of the enzyme was studied in presence of various starchy residues and metal ions. HgCl2, CuSO4 and FeCl3 caused inhibition of the enzyme. The reaction conditions, pH and temperature, was optimized using response surface methodology. At the optimum pH and temperature of 4.9 and 57ºC, the apparent activity was 25.6U/g of beads, resulting in almost 2-fold increase in activity. The immobilized enzyme showed a high operational stability by retaining almost 85% of the initial activity after seventh use.


2004 ◽  
Vol 70 (4) ◽  
pp. 2367-2372 ◽  
Author(s):  
Xiaokun Wang ◽  
Xin Geng ◽  
Yukari Egashira ◽  
Hiroo Sanada

ABSTRACT Dietary ferulic acid (FA), a significant antioxidant substance, is currently the subject of extensive research. FA in cereals exists mainly as feruloylated sugar ester. To release FA from food matrices, it is necessary to cleave ester cross-linking by feruloyl esterase (FAE) (hydroxycinnamoyl esterase; EC 3.1.1.73). In the present study, the FAE from a human typical intestinal bacterium, Lactobacillus acidophilus, was isolated, purified, and characterized for the first time. The enzyme was purified in successive steps including hydrophobic interaction chromatography and anion-exchange chromatography. The purified FAE appeared as a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular mass of 36 kDa. It has optimum pH and temperature characteristics (5.6 and 37°C, respectively). The metal ions Cu2+ and Fe3+ (at a concentration of 5 mmol liter−1) inhibited FAE activity by 97.25 and 94.80%, respectively. Under optimum pH and temperature with 5-O-feruloyl-l-arabinofuranose (FAA) as a substrate, the enzyme exhibited a K m of 0.0953 mmol liter−1 and a V max of 86.27 mmol liter−1 min−1 mg−1 of protein. Furthermore, the N-terminal amino acid sequence of the purified FAE was found to be A R V E K P R K V I L V G D G A V G S T. The FAE released FA from O-(5-O-feruloyl-α-l-arabinofuranosyl)-(1→3)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose (FAXX) and FAA obtained from refined corn bran. Moreover, it released two times more FA from FAXX in the presence of added xylanase.


1988 ◽  
Vol 66 (6) ◽  
pp. 1186-1191 ◽  
Author(s):  
Alejandra Vazquez ◽  
Jorge Vazquez-Ramos

Two types of DNA synthesis have been detected during maize germination (0–24 h). To determine if the difference in these two types of synthesis was due to the presence of distinct DNA polymerases, we partially isolated and characterized the enzymes present at 3 (early) and 24 (late) h of germination. The material used was embryo axes. The result indicates that at both 3 and 24 h, enzymes are similar with regard to optimum pH and temperature, absolute requirement of Mg2+ (12 mM), and stimulation by KCl (50 mM). They are also equally inhibited by N-ethylmaleimide and cytosine-β-D-arabinofuranoside. These facts would classify the enzymes as alpha type; however, the enzymes differ in their sensitivity to aphidicolin and the degree of purification. The nature of the enzymes is discussed.


1989 ◽  
Vol 33 (11) ◽  
pp. 1419-1424 ◽  
Author(s):  
Jeff. L Harmon ◽  
Gerasimos Lyberatos ◽  
Spyros A. Svoronos

2010 ◽  
Vol 113-116 ◽  
pp. 226-230 ◽  
Author(s):  
Chun Lei Wang ◽  
Min Zhao ◽  
Xing Dong Wei ◽  
Tai Lun Li ◽  
Lei Lu

Treatment of xenobiotic compounds such as textile dyes with bacterial laccases is limited to the acid pH range and moderate temperatures. A bacterial strain, designated as WD23, was isolated from forest soil using Luria-Bertani medium supplemented with 0.4 mmol/L Cu2+. The isolated strain was identified as Bacillus subtilis by physiological and biochemical tests and 16S rDNA sequence analysis. Here we charactered the spore-bound laccase of B. subtilis WD23 and used the laccase to decolorize dyes. The spores of the strain showed laccase-like activity, oxidizing syringaldazine, 2,6-dimethoxyphenol and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonate acid)(ABTS). The optimum pH and temperature for the spore-bound laccase were 6.8 and 60°C, respectively. It also showed higher stabilities over a broad pH range, the pH half-life was more than 6 months at pH 6.8. The spore laccase could efficiently decolorize 50~90% of anthraquinone and azo dyes in 24 h. The spore laccase can play an important role in bioremediation.


2013 ◽  
Vol 864-867 ◽  
pp. 1262-1265 ◽  
Author(s):  
Bo Yang ◽  
Xu Ming Wang

Coordinated chitosan-Cu2+ as a carrier, the laccase was immobilized on it by polymeric coordination method. In this study, the optimal conditions for immobilization and properties of laccase were investigated. The optimal conditions for immobilization were: CuSO4 (0.05 mol/L), complex time (7 h), laccase concentration (250 U/mL), immobilization time (8 h). Under this condition, the activity of immobilized laccase can reach 820 U/g. In comparison with the free laccase, the optimum pH and temperature of immobilized laccase have a little change, while the heat resistance and pH stability were improved. After the immobilized laccase was stored in the refrigerator at 4 °C for 25 days, the activity of it remained 69.5 % of the original, it illustrates the immobilized laccase has a good storage stability. The laccase immobilized with chitosan-Cu2+ has high activity and has potential to use in industry as a biocatalyst.


Author(s):  
N. V. Statsyuk ◽  
L. A. Shcherbakova ◽  
O. D. Mikityuk ◽  
T. A. Nazarova ◽  
V. G. Dzhavakhiya

Extracellular metabolites of Gliocladium roseum GRZ7 are able to destroy aflatoxin B1 and zearalenone (by 61.9 and 68%, respectively). The determined optimum pH and temperature confirm the enzymatic nature of these metabolites.


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