scholarly journals An Active of Extracellular Cellulose Degrading Enzyme from Termite Bacterial Endosimbiont

2016 ◽  
Vol 20 (1) ◽  
pp. 62
Author(s):  
M. Saifur Rohman ◽  
Endang Pamulatsih ◽  
Yudi Kusnadi ◽  
Triwibowo Yuwono ◽  
Erni Martani

Cellulase is an ezyme that specifically cleaves the 1,4-β-glycosidic bond of cellulose to produce thesmall fragments of simple carbohydrate. This work was aimed to characterize the extracellular cellulase fromPaenibacillus spp., which was previously isolated from macro termites, Odontotermes bhagwatii in our laboratory.Two Paenibacillus isolates were used in this experiment, namely Paenibacillus cellulositrophicus SBT1 andPaenibacillus, sp. SBT8. Analysis of the total proteins in the supernatants showed that P. cellulositrophicus SBT1and Paenibacillus sp. SBT8 roughly produced as much as 18.6 mg/l and 24.8 mg/l of extracellular cellulases,respectively. Enzymatic assay showed that SBT1 and SBT8 cellulase exhibited enzymatic acitivity of 0.17 U/mg and 0.12 U/mg, respectively. Temperature dependencies analysis indicated that both cellulases exhibitedmaximum activity at 35oC. At the temperature higher than 55oC, the enzymatic activities of both cellulases wereroughly 20% reduced compared to the maximum activity. SBT1 and SBT8 cellulases were both active at acidicpH. At basic pH (pH 8) the enzymatic activities of both cellulases were reduced roughly 30% compared to thatof acidic pH. Supplementing of Mg2+, Zn2+, and Ca2+ in range of 1-10 mM increased the enzymatic activity ofboth cellulases roughly 33 to 50%.

2012 ◽  
Vol 287 (15) ◽  
pp. 12405-12416 ◽  
Author(s):  
Tong Zhang ◽  
Jhoanna G. Berrocal ◽  
Jie Yao ◽  
Michelle E. DuMond ◽  
Raga Krishnakumar ◽  
...  

NMNAT-1 and PARP-1, two key enzymes in the NAD+ metabolic pathway, localize to the nucleus where integration of their enzymatic activities has the potential to control a variety of nuclear processes. Using a variety of biochemical, molecular, cell-based, and genomic assays, we show that NMNAT-1 and PARP-1 physically and functionally interact at target gene promoters in MCF-7 cells. Specifically, we show that PARP-1 recruits NMNAT-1 to promoters where it produces NAD+ to support PARP-1 catalytic activity, but also enhances the enzymatic activity of PARP-1 independently of NAD+ production. Furthermore, using two-photon excitation microscopy, we show that NMNAT-1 catalyzes the production of NAD+ in a nuclear pool that may be distinct from other cellular compartments. In expression microarray experiments, depletion of NMNAT-1 or PARP-1 alters the expression of about 200 protein-coding genes each, with about 10% overlap between the two gene sets. NMNAT-1 enzymatic activity is required for PARP-1-dependent poly(ADP-ribosyl)ation at the promoters of commonly regulated target genes, as well as the expression of those target genes. Collectively, our studies link the enzymatic activities of NMNAT-1 and PARP-1 to the regulation of a set of common target genes through functional interactions at target gene promoters.


2016 ◽  
Vol 68 (2) ◽  
pp. 451-459
Author(s):  
Urszula Jankiewicz ◽  
Maria Swiontek-Brzezinska

The aim of the study was to detect the activity and characterize potentially fungistatic chitinases synthesized by rhizosphere bacteria identified as Paenibacillus sp. M4. Maximum chitinolytic activity was achieved on the fifth day of culturing bacteria in a growth medium with 1% colloidal chitin. Analysis of a zymogram uncovered the presence of four activity bands in the crude bacterial extract. The used three-stage protein purification procedure resulted in a single band of chitinase activity on the zymogram. The purified enzyme exhibited maximum activity at pH 6.5 and temperature 45oC, and thermal stability at 40oC for 4 h. In terms of substrate specificity, it is an exochitinase (chitobiose). The amino acid sequence obtained after mass spectrometry showed similarity to chitinase A1 synthesized by Bacillus circulans. The M4 isolate demonstrated the highest growth inhibiting activity against plant pathogens belonging to the genera Fusarium, Rhizoctonia and Alternaria. Fungistatic activity, although to a somewhat lesser degree, was also demonstrated by purified chitinase. The obtained results confirm the participation of the studied exochitinase in antagonism towards pathogenic molds. However, the lower fungistatic effectiveness of the chitinases points to the synergistic action of different metabolites in biocontrol by these bacteria.


Author(s):  
Javier Espinoza-Vergara ◽  
Paulo Molina ◽  
Mariana Walter ◽  
Miguel Gulppi ◽  
Nelson Vejar ◽  
...  

The influence of pH on the electrochemical behavior of hydrogen peroxide in the presence of Pseudomonas aeruginosa was investigated using electrochemical techniques. Cyclic and square wave voltammetry were used to monitor the enzymatic activity. A modified cobalt phthalocyanine (CoPc) carbon electrode (OPG), a known catalyst for reducing O2 to H2O2, was used to detect species resulting from the enzyme activity. The electrolyte was a sterilized aqueous medium containing Mueller-Hinton (MH) broth. The open-circuit potential (OCP) of the Pseudomonas aeruginosa culture in MH decreased rapidly with time, reaching a stable state after 4 h. Peculiarities in the E / I response were observed in voltammograms conducted in less than 4 h of exposure to the culture medium. Such particular E/I responses are due to the catalase’s enzymatic action related to the conversion of hydrogen peroxide to oxygen, confirming the authors’ previous findings related to the behavior of other catalase-positive microorganisms. The enzymatic activity exhibits maximum activity at pH 7.5, assessed by the potential at which oxygen is reduced to hydrogen peroxide. At higher or lower pHs, the oxygen reduction reaction (ORR) occurs at higher overpotentials, i.e., at more negative potentials. In addition, and to assess the influence of bacterial adhesion on the electrochemical behavior, measurements of the bacterial-substrate metal interaction were performed at different pH using atomic force microscopy.


Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Trung Dung Tran ◽  
Anh Dzung Nguyen ◽  
...  

Chitosan oligosaccharide (COS) has become of great interest in recent years because of its worthy biological activities. This study aims to produce COS using the enzymatic method, and investigates Paenibacillus sp. TKU047, a chitinolytic-producing strain, in terms of its chitosanase productivity on several chitinous material-containing mediums from fishery process wastes. The highest amount of chitosanase was produced on the medium using 2% (w/v) squid pens powder (0.60 U/mL) as the single carbon and nitrogen (C/N) source. The molecular mass of TKU047 chitosanase, which could be the smallest one among chitinases/chitosanases from the Paenibacillus genus, was approximately 23 kDa according to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. TKU047 chitosanase possessed the highest activity at 60 °C, pH 7, and toward chitosan solution with a higher degree of deacetylation (DDA) value. Additionally, the hydrolysis products of 98% DDA chitosan catalyzed by TKU047 chitosanase showed the degree of polymerization (DP) ranging from 2 to 9, suggesting that it was an endo-type activity chitosanase. The free radical scavenging activity of the obtained chitosan oligosaccharide (COS) was determined. The result showed that COS produced with Paenibacillus sp. TKU047 chitosanase expressed a higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than that from the commercial COSs with maximum activity and IC50 values of 81.20% and 1.02 mg/mL; 18.63% and 15.37 mg/mL; and 15.96% and 15.16 mg/mL, respectively. As such, Paenibacillus sp. TKU047 may have potential use in converting squid pens waste to produce chitosanase as an enzyme for bio-activity COS preparation.


2012 ◽  
Vol 7 (1) ◽  
pp. 165-172 ◽  
Author(s):  
Markus P. Kummer ◽  
Claudia Hülsmann ◽  
Michael Hermes ◽  
Daisy Axt ◽  
Michael T. Heneka

Author(s):  
Maria- Mihaela MICUȚI ◽  
Liliana BĂDULESCU ◽  
Florentina ISRAEL-ROMING

The focus of this article is to provide informations about soil enzymatic activity as a biological indicator for impacts of pesticides on soils. In this experiment, an ecological soil was treated with two types of fungicide (Ridomil Gold and Bravo 500) and two of insecticides (Mospilan 20SG and Vertimec 1.8% EC). The pesticides were assessed for their effect on different enzymatic activities. They were administrated over a 28 days period and the samples of soil were taken once every 7 days and analyzed in the laboratory. For each sample was determined the enzymatic activity, pH, humidity. The enzymatic activity was assessed using colorimetrical methods. Enzymes chosen for this study were cellulase, amylase, xylanase, urease, alkaline and acid phosphatase. Results shown that the enzymatic activity can increase or decrease when the soil was treated with the fungicides and insecticides chosen for this experiment.


Hoehnea ◽  
2018 ◽  
Vol 45 (1) ◽  
pp. 134-142 ◽  
Author(s):  
Flaviane Lopes Ferreira ◽  
Cesar Barretta Dall'Antonia ◽  
Emerson Andrade Shiga ◽  
Larissa Juliani Alvim ◽  
Rosemeire Aparecida Bom Pessoni

ABSTRACT The aim of the present work was to assess the enzymatic activity of six strains of filamentous fungi grown in liquid media containing 1% sugarcane bagasse as the sole carbon source. All fungal strains were able to use this agro-industrial residue, producing various types of enzymes, such as cellulases, xylanases, amylases, pectinases, and laccases. However, Aspergillus japonicus Saito was the most efficient producer, showing the highest enzymatic activity for laccase (395.73 U L-1), endo-β-1,4-xylanase (3.55 U mL-1) and β-xylosidase (9.74 U mL-1) at seven, fourteen and twenty-one days in culture, respectively. Furthermore, the endo-β-1,4-xylanases and β-xylosidases of A. japonicus showed maximum activity at 50°C, and pH 5.5 and pH 3.5-4.5, respectively. Thus, these results indicate that A. japonicus has a great biotechnological potential for the production of these enzymes using sugarcane bagasse as the sole source of carbon.


2019 ◽  
Vol 60 (12) ◽  
pp. 2672-2683 ◽  
Author(s):  
HyunSeok Lim ◽  
Ayumi Tanaka ◽  
Ryouichi Tanaka ◽  
Hisashi Ito

Abstract In plants, chlorophyll (Chl) a and b are interconvertible by the action of three enzymes—chlorophyllide a oxygenase, Chl b reductase (CBR) and 7-hydroxymethyl chlorophyll a reductase (HCAR). These reactions are collectively referred to as the Chl cycle. In plants, this cyclic pathway ubiquitously exists and plays essential roles in acclimation to different light conditions at various developmental stages. By contrast, only a limited number of cyanobacteria species produce Chl b, and these include Prochlorococcus, Prochloron, Prochlorothrix and Acaryochloris. In this study, we investigated a possible existence of the Chl cycle in Chl b synthesizing cyanobacteria by testing in vitro enzymatic activities of CBR and HCAR homologs from Prochlorothrix hollandica and Acaryochloris RCC1774. All of these proteins show respective CBR and HCAR activity in vitro, indicating that both cyanobacteria possess the potential to complete the Chl cycle. It is also found that CBR and HCAR orthologs are distributed only in the Chl b-containing cyanobacteria that habitat shallow seas or freshwater, where light conditions change dynamically, whereas they are not found in Prochlorococcus species that usually habitat environments with fixed lighting. Taken together, our results implicate a possibility that the Chl cycle functions for light acclimation in Chl b-containing cyanobacteria.


1981 ◽  
Vol 27 (11) ◽  
pp. 1140-1149 ◽  
Author(s):  
George M. Carman ◽  
Jonathan Matas

Membrane-associated cytidine 5′-diphospho-1,2-diacyl-sn-glycerol (CDP-diacylglycerol):L-serine O-phosphatidyltransferase (phosphatidylserine synthase, EC 2.7.8.8.) and CDP-diacylglycerol: myo-inositol phosphatidyltransferase (phosphatidyl-inositol synthase, EC 2.7.8.11) were solubilized from the microsomal fraction of Saccharomyces cerevisiae. A variety of detergents were examined for their ability to release phosphatidylserine synthase and phosphatidylinositol synthase activities from the microsome fraction. Both enzymes were solubilized from the microsome fraction with Renex 690 in yields over 80% with increases in specific activity of 1.6-fold. Both solubilized enzymatic activities were dependent on manganese ions and Triton X-100 for maximum activity. The pH optimum for each reaction was 8.0. The apparent Km values for CDP-diacylglycerol and serine for the phosphatidylserine synthase reaction were 0.1 and 0.25 mM, respectively. The apparent Km values for CDP-diacylglycerol and inositol for the phosphatidylinositol synthase reaction were 70 μM and 0.1 mM, respectively. Thiore-active agents inhibited both enzymatic activities. Both solubilized enzymatic activities were thermally inactivated at temperatures above 30 °C.


1967 ◽  
Vol 13 (9) ◽  
pp. 1133-1138 ◽  
Author(s):  
Norvell W. Hunter

Spectrophotometric methods were used to study the activity of the leucine naphthylamidases of Paramecium caudatum. Optimum activity of the enzymes occurred from pH 6.6 to 6.8 and was enhanced by either Co2+, Mn2+, or by Mg2+. Maximum activity occurred when Co2+ was used with either Mg2+ or Mn2+. Activity was depressed by either Sr2+, Fe2+, Zn2+, Ni2+, Hg2+, Cd2+, Pb2+, Sn2+, or Li2+, and not affected by Ba2+, Cu2+, and Ca2+. Approximately 40% of the enzymatic activity was inhibited by EDTA. Most of this inhibition was reversed by either Mg2+, Co2+, or Mn2+.


Sign in / Sign up

Export Citation Format

Share Document