QUANTITATIVE STUDIES OF HYDROLYTIC ENZYME ACTIVITY IN THE SALIVARY GLAND OF CHIRONOMUS TENTANS (DIPTERA: CHIRONOMIDAE) DURING METAMORPHOSIS

1971 ◽  
Vol 103 (3) ◽  
pp. 454-457 ◽  
Author(s):  
Hans Laufer ◽  
Ki Ssu Schin

AbstractChanges in the hydrolytic enzymes, ribonuclease and acid phosphatase were investigated in the salivary gland of Chironomus tentans since these lysosomal enzymes may participate in hormonally stimulated tissue breakdown. Quantitative assays revealed 9- and 12-fold increases in the specific activity of these enzymes during pupation while the protein content of the gland was decreasing. These increases cannot be accounted for by decreased protein but may represent an activation, accumulation, or synthesis which seems to be important in gland breakdown at metamorphosis.

2009 ◽  
Vol 2 (3) ◽  
pp. 313-322 ◽  
Author(s):  
S. Alam ◽  
H. Shah ◽  
N. Magan

The objectives of this study were to examine the effect of different water activities (aw; 0.99, 0.96 and 0.94) and time (up to 120 h) on quantitative and specific enzyme production during germination and initial growth of Aspergillus flavus and A. parasiticus strains at 25 °C. This is an important early indicator of potential for aflatoxin production under conducive conditions. Qualitative API ZYM generic enzyme strips were used to identify key hydrolytic enzymes produced. Subsequently, the temporal effects of aw on the total/specific activity of the key 4-5 hydrolytic enzymes were determined using 4-nitrophenyl substrates in a 96-well microtitre plate assay. The main enzymes produced by germinating conidia of A. flavus were esterase, lipase, acid phosphatase, β-glucosidase and N-acetyl-β-D-glucosaminidase, while for A. parasiticus these were alkaline phosphatase, lipase, acid phosphatase and β-fucosidase for both total (µmol 4-nitrophenol/min/g) and specific activity (nmol 4-nitrophenol/min/µg protein). There were significant increases in the specific activity of all these enzymes of germinating spores of A. flavus (0-120 h) except for β-glucosidase which was maximum at 72 h. The total/specific activities of the enzymes produced by A. flavus were maximum at 0.99 aw, with the exception of acid phosphatase and N-acetyl-β-D-glucosaminidase at 0.94 aw. For A. parasiticus, maximum total activity occurred at 0.99 aw for fucosidase activity, while specific activity was found to be higher at lower aw levels. These enzymes are important in early colonisation of food matrices by these species and single factors (aw, time) and two-way interactions were all statistically significant for the enzymes assayed for both species. These enzymes could be used as an early and rapid indicator of the activity of Aspergillus section flavi species and suggests that rapid infection may occur over a wide range of aw conditions.


2020 ◽  
Vol 8 (2) ◽  
pp. 267
Author(s):  
Nursatria Purba ◽  
Ida Bagus Wayan Gunam ◽  
I Made Mahaputra Wijaya

The purpose of this study was determined the media and concentration of cellulolytic bacterial isolates to produce high cellulase enzyme activity. Production of crude cellulase enzyme in media and concentration of different bacterial isolate used a factorial Randomized Block Design (RBD) which consist of two factors. The first factor was the media production of different cellulase enzyme consisting of 3 levels, namely media 1, 2 and 3. The second factor was the concentration of bacterial isolate consisting of 5 levels namely 1, 2, 3, 4 and 5%. This study used a B2S8 cellulolytic bacterial isolate that has the highest value of cellulase enzyme activity and the highest degradation rate of cellulose in previous studied and determined the ability of exoglucanase enzyme activity, endoglucanase enzyme and dissolved protein content produced from cellulolytic bacterial isolate. This study used Carboxymethyl Cellulose (CMC) for enzyme activity test and 1% corn stover as a substrate on the media to produce crude cellulase enzyme. The result showed that the highest cellulase enzyme activity in the third media and 5% cellulolytic bacterial inoculum concentration resulted in endoglucanase activity of 0.0332 IU/mL, exoglucanases enzyme activity of 0.0060 IU/mL, dissolved protein content in the amount of 0.5670 mg/mL, the specific endoglucanase activity of 0.0807 IU/mg and the specific activity of exoglucanase of 0.0123 IU/mg. Keywords: Cellulolytic bacteria, Cellulase enzymes, Enzyme activity, Corn stover


1965 ◽  
Vol 121 (5) ◽  
pp. 835-848 ◽  
Author(s):  
Zanvil A. Cohn ◽  
Belinda Benson

The concentration of newborn calf serum in the medium has marked effects on the morphological and biochemical properties of mouse mononuclear phagocytes. At a low serum concentration, the cells developed small numbers of tiny cytoplasmic granules and little or no increase in acid phosphatase, cathepsin, and ß-glucuronidase. As the serum concentration was raised, granules were formed at a more rapid rate and were larger in size. The rate of production and total amount of three hydrolytic enzymes was increased at higher levels of serum. Observations on living cells indicated that the phase-dense granules which accumulated in the perinuclear region were derived from pinocytic vesicles. These clear vesicles fused and migrated to the centrosphere where they underwent a gradual increase in phase density and reacted positively for acid phosphatase. A microscopic technique was described for the evaluation of the pinocytic process. When this method was employed, the rate of pinocytosis increased curvilinearly with elevations in the calf serum concentration of the medium. The comparative influence of bovine, horse, and rabbit serum on mouse cells was evaluated. It is suggested that pinocytosis is a major regulator of granule formation and hydrolytic enzyme production by the mouse macrophage.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 335-343 ◽  
Author(s):  
Rajeev Goel ◽  
Takashi Mino ◽  
Hiroyasu Satoh ◽  
Tomonori Matsuo

Enzymatic hydrolysis under different electron acceptor conditions in nutrient removal activated sludge treatment processes is a weak link in the Activated Sludge Model no. 2 (Henze et al., 1995). An experimental study was undertaken to gain insight into the hydrolysis process with specific focus on hydrolysis kinetics and rates under different electron acceptor conditions. Two pure cultures, Bacillus amyloliquefaciens (Gram positive) and Pseudomonas saccharophila (Gram negative) were chosen for the study. In addition, activated sludge grown in an anaerobic-aerobic system was tested for enzymatic activity using starch as the model substrate. The hydrolytic enzymes were found to be released into the bulk in pure cultures whereas the enzyme activity was found to be mainly associated with the cell surfaces in activated sludge. Further, it was observed that the development of the hydrolytic enzyme system in Bacillus amyloliquefaciens and P. saccharophila is strongly suppressed under anoxic and anaerobic conditions. However, the effect of anaerobic and aerobic incubation on hydrolytic enzyme activity in activated sludge was found to be small. Starch hydrolysis kinetic data from batch experiments with activated sludge followed substrate saturation kinetics that were linear with biomass concentration. Finally, the similar hydrolytic enzyme activities observed under anaerobic and aerobic phases of a sequencing batch reactor are explained by considering the aspects of enzyme location and enzyme system development under aerobic and anaerobic phases. It is proposed that the floc bound enzymes are recycled in a single sludge system so that an equilibrium exists between enzyme loss and synthesis at steady state.


1968 ◽  
Vol 16 (4) ◽  
pp. 249-262 ◽  
Author(s):  
ZOLTAN POSALAKI ◽  
DEZSÖ SZABÓ ◽  
ERNÖ BÁCSI ◽  
ISTVÁN ÖKRÖS

The localization of lipids and the activities of nonspecific esterase, aryl sulfatase and acid phosphatase were studied in different stages of spermatogenesis in rats. In addition, the distribution of acid phosphatase activity was demonstrated electron histochemically. The spermatogenetic cycle was divided into two phases—corresponding to the first and the last four stages of Roosen-Runge-Giesel (RG) classification. Spermatids in the first phase contained abundant endoplasmic reticulum with rosette formation and well developed Golgi apparatus with numerous vesicles. They displayed high activity of hydrolytic enzymes but contained no appreciable amount of lipids. The Sertoli cells contained large lipid granules but showed minimal enzyme activity. During the second phase reduction of the cytoplasm of spermatids with fragmentation of the endoplasmic reticulum and Golgi lamellae, accumulation of lipids, aggregation of ribonucleo-protein particles, formation of residual bodies and marked decrease of enzyme activity were seen. The Sertoli cells contained large mitochondria, well developed endoplasmic reticulum and numerous dense bodies and revealed high activities of hydrolytic enzymes and rapid depletion of lipids. These ultrastructural and histochemical findings suggested an interaction between the Sertoli cells and the developing spermatids which probably contributed to the regulation of spermatogenesis.


1967 ◽  
Vol 21 (1) ◽  
pp. 147-154 ◽  
Author(s):  
J. Bunyan ◽  
J. Green ◽  
A. T. Diplock ◽  
D. Robinson

1. The activities of several lysosomal hydrolases have been measured in tissues of rats with nutritional liver necrosis. Incipient or actual liver necrosis did not alter total, free or unsedimentable activities of cathepsin, β-glucuronidase, β-galactosidase or acid phosphatase of liver and kidney. Free hydrolytic activity towards p-nitrophenyl phosphate was slightly raised in liver, and serum β-galactosidase and β-glucuronidase were moderately elevated. These results suggest that lysosomal hydrolases are not directly implicated in the causation of liver necrosis.2. Testicular degeneration was studied with reference to changes in β-giucuronidase activity. This enzyme activity, total, free and unsedimentable, was raised in deficient rat testis at 6 months old and did not decline even after a year. Raised values were also found in serum.


2016 ◽  
Vol 60 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Ivana Flanjak ◽  
Ivica Strelec ◽  
Daniela Kenjerić ◽  
Ljiljana Primorac

Abstract In honey, the content of proteins, including the enzymes, is relatively low and has a minor nutritive significance. On the other hand, the proteins, including the enzymes, are usually used as honey quality evaluation parameters. This is because protein content and enzyme activities vary regarding the botanical origin of the honey. Since the results of protein content, glucose-oxidase, and acid phosphatase, for honeys produced in Croatia, are not available, four of the most abundant honey types produced in Croatia (black locust, sage, chestnut, and honeydew honey) are characterised according to the protein and proline content and enzyme activities. The characterisation was done to determine specificities and contribute to the characterisation of unifloral honeys. Dark honey types (honeydew and chestnut honey) had a higher proline content, and diastase, invertase, and glucose-oxidase activity than lighter sage and black locust honey. Black locust honey has a naturally low enzyme activity and showed the highest acid phosphatase activity among the analysed honey types, while honeydew honey, otherwise known to possess high proline content and enzyme activity, had a low protein content comparable to black locust honey. Statistically significant correlations were obtained between all analysed parameters, with the exception of acid phosphatase activity.


2021 ◽  
Vol 42 (4(SI)) ◽  
pp. 1195-1200
Author(s):  
S. Thirukkumar ◽  
◽  
G. Hemalatha ◽  
S. Vellaikumar ◽  
M. Murugan ◽  
...  

Aim: This research aimed to optimize suitable hydrolytic enzymes for maximizing cottonseed milk extracts for high cottonseed milk yield, protein content and low gossypol level. Methodology: Known amount of cottonseed was soaked for 90 min at 32°C and blended (cottonseed:water@1:6). Different aliquots of the blended cottonseed slurry were treated with 1% of enzymes viz., protease, cellulase and α-amylase enzyme at pH 7.0 followed by incubation at 40 and 52°C for 2.30 hr for the extraction of cottonseed milk. The enzyme activity of extracted milk was subsequently inactivated by pasteurization (90°C, 5 min). Further analysis of physico-chemical characteristics was also carried. The control sample included milk extraction from non-enzyme treated cottonseed milk extract (30±2°C). Results: Among different treatments, cottonseed milk extraction using protease enzyme at 40°C incubation showed the highest milk yield (86.71%) with the lowest sedimentation (3.72%). Further incubation 40°C and 52°C showed the highest protein content of 2.10 and 2.27 g 100 ml-1 and gossypol reduction of 40.36 and 35.22%, respectively, in the cottonseed milk extract. Meanwhile, cellulase and α-amylase enzymes treated samples at both incubation temperatures showed poor physico-chemical characteristics as compared to control. Interpretation: Protease enzyme seems to be the most suitable for optimum or higher extraction of cottonseed milk.


1965 ◽  
Vol 25 (1) ◽  
pp. 97-102 ◽  
Author(s):  
Hans Laufer ◽  
Yasukiyo Nakase

The deoxyribonuclease (DNase) activity of the dipteran (Chironomus thummi) salivary gland, measured both enzymatically and immunochemically, increases about 7-fold with the onset of metamorphosis. The increase in DNase activity occurs at a time when the activities of other enzymes and the total protein content are decreasing. The increased DNase activity is followed by glandular destruction. It is suggested that the alterations of this activity may be regulated by the activities of specific chromosomal sites, and that the enzyme may, at least in part, account for the glandular destruction observed at the time of increased enzyme activity.


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