scholarly journals The role of exochitinase type A1 in the fungistatic activity of the rhizosphere bacterium Paenibacillus sp. M4

2016 ◽  
Vol 68 (2) ◽  
pp. 451-459
Author(s):  
Urszula Jankiewicz ◽  
Maria Swiontek-Brzezinska
Keyword(s):  
Plant Pathogens ◽  
Chitinase Activity ◽  
Maximum Activity ◽  
Synergistic Action ◽  
Chitinolytic Activity ◽  
Fungistatic Activity ◽  
Rhizosphere Bacterium ◽  
Paenibacillus Sp ◽  
Growth Inhibiting

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.

Defensive Role of Plant-Derived Secondary Metabolites: Indole and Its’ Derivatives

2020 ◽  
Vol 9 (2) ◽  
pp. 78-88
Author(s):  
Mulugeta Mulat ◽  
Raksha Anand ◽  
Fazlurrahman Khan
Keyword(s):  
Biofilm Formation ◽  
Growth And Development ◽  
Functional Role ◽  
Plant Pathogens ◽  
Bacterial Species ◽  
Indole Derivatives ◽  
Resistance Level ◽  
Defensive Role ◽  
Insect Attack

The diversity of indole concerning its production and functional role has increased in both prokaryotic and eukaryotic systems. The bacterial species produce indole and use it as a signaling molecule at interspecies, intraspecies, and even at an interkingdom level for controlling the capability of drug resistance, level of virulence, and biofilm formation. Numerous indole derivatives have been found to play an important role in the different systems and are reported to occur in various bacteria, plants, human, and plant pathogens. Indole and its derivatives have been recognized for a defensive role against pests and insects in the plant kingdom. These indole derivatives are produced as a result of the breakdown of glucosinolate products at the time of insect attack or physical damages. Apart from the defensive role of these products, in plants, they also exhibit several other secondary responses that may contribute directly or indirectly to the growth and development. The present review summarized recent signs of progress on the functional properties of indole and its derivatives in different plant systems. The molecular mechanism involved in the defensive role played by indole as well as its’ derivative in the plants has also been explained. Furthermore, the perspectives of indole and its derivatives (natural or synthetic) in understanding the involvement of these compounds in diverse plants have also been discussed.

Heat-shock-induced grey crescent formation in axolotl eggs and oocytes: the role of gravity

Development ◽  
1987 ◽  
Vol 100 (4) ◽  
pp. 599-609
Author(s):  
J.-C. Beetschen ◽  
J. Gautier
Keyword(s):  
Protein Synthesis ◽  
Heat Shock ◽  
Synergistic Action ◽  
Nuclear Factor ◽  
Crescent Formation ◽  
Animal Pole ◽  
Grey Crescent ◽  
Cytoskeletal Structure

Axolotl eggs were heat shocked (36.8°C, 10min) inside their jelly layers. Heat shock (HS) was shown to induce the precocious appearance of a grey crescent (GC) in a number of eggs immediately after fertilization (Benford & Namenwirth, 1974). It was also demonstrated that this phenomenon occurs in fertilized or artificially activated eggs only when they are shocked within 11/2h after spawning. The GC forms still later in heated unfertilized, nonactivated eggs. The role of the jelly layers is considered to be mechanical: a proportion of eggs is maintained in a tilted position until the egg is able to orient animal pole upwards under the influence of gravity as a late consequence of activation. The jelly layers are not essential if the eggs are artificially tilted or rotated during HS. GC formation can also be induced in in vitro maturing oocytes, provided they are tilted during HS. Gravity thus plays an essential role in the cytoplasmic rearrangements leading to HS-induced GC formation. Our results indicate a synergistic action between heat and gravity in this process. The cytological appearance of the GC formed in those experiments is that of a ‘Born's crescent’ with a conspicuous ‘vitelline wall’ (Pasteels, 1964). When oocytes are enucleated before maturation, HS has no effect on GC formation. A nuclear factor is therefore essential, as has been demonstrated in early GC formation induced by inhibitors of protein synthesis. Finally, incorporation of amino acids into oocyte proteins appears to be rapidly inhibited by HS (from 5 min). However, we cannot conclude that GC formation is in fact triggered by inhibition of protein synthesis. It is also likely that HS disrupts cytoskeletal structure, hence facilitating cytoplasmic rearrangements. Nevertheless, these results are in agreement with the scheme we recently proposed for GC formation in the rotated axolotl oocyte (Gautier & Beetschen, 1985).

scholarly journals Phylogenetic and Functional Diversity of Saprolegniales and Fungi Isolated from Temperate Lakes in Northeast Germany

2021 ◽  
Vol 7 (11) ◽  
pp. 968
Author(s):  
Hossein Masigol ◽  
Jason Nicholas Woodhouse ◽  
Pieter van West ◽  
Reza Mostowfizadeh-Ghalamfarsa ◽  
Keilor Rojas-Jimenez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Enzymatic Activity ◽  
Humic Substances ◽  
Plant Litter ◽  
Freshwater Ecosystems ◽  
Chitinolytic Activity ◽  
Ecological Implications ◽  
Eukaryotic Organisms

The contribution of fungi to the degradation of plant litter and transformation of dissolved organic matter (humic substances, in particular) in freshwater ecosystems has received increasing attention recently. However, the role of Saprolegniales as one of the most common eukaryotic organisms is rarely studied. In this study, we isolated and phylogenetically placed 51 fungal and 62 Saprolegniales strains from 12 German lakes. We studied the cellulo-, lignino-, and chitinolytic activity of the strains using plate assays. Furthermore, we determined the capacity of 10 selected strains to utilize 95 different labile compounds, using Biolog FF MicroPlates™. Finally, the ability of three selected strains to utilize maltose and degrade/produce humic substances was measured. Cladosporium and Penicillium were amongst the most prevalent fungal strains, while Saprolegnia, Achlya, and Leptolegnia were the most frequent Saprolegniales strains. Although the isolated strains assigned to genera were phylogenetically similar, their enzymatic activity and physiological profiling were quite diverse. Our results indicate that Saprolegniales, in contrast to fungi, lack ligninolytic activity and are not involved in the production/transformation of humic substances. We hypothesize that Saprolegniales and fungi might have complementary roles in interacting with dissolved organic matter, which has ecological implications for carbon cycling in freshwater ecosystems.

Purification and properties of glutamate-phenylpyruvate aminotransferase from the ruminal protozoan Entodinium caudatum

2004 ◽  
Vol 55 (9) ◽  
pp. 991
Author(s):  
Md. Ruhul Amin ◽  
Ryoji Onodera ◽  
R. Islam Khan ◽  
R. John Wallace ◽  
C. Jamie Newbold
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Maximum Activity ◽  
Purification And Properties ◽  
Sds Page ◽  
Wide Range ◽  
S 100 ◽  
A Cell

Entodinium species are important in catabolic protein metabolism by the mixed ruminal microbial population. This study was conducted to purify, and investigate properties of one of the enzymes involved in amino acid metabolism by Entodinium caudatum, glutamate-phenylpyruvate aminotransferase (GPA; EC 2.6.1.64). GPA was purified 74-fold from a cell-free extract by ammonium sulfate precipitation and column chromatography with phenyl-superose, DEAE-Toyopearl 650M, Sephacryl S-100 HR, and Sephadex G-100. The molecular mass of GPA was estimated by SDS–PAGE to be 65.0 kDa. The optimum pH was 6.0 and it was found to be reactive over a wide range of pH from 5.0 to 10.5. Maximum activity of GPA occurred at 45°C and the activity declined at temperatures over 55°C. GPA was stable below 60°C. Aminooxyacetate and phenylhydrazine were highly inhibitory, and SDS, EDTA, and some heavy metal ions also inhibited activity. The purification and characterisation of the enzyme will help to isolate the gene and ultimately to understand the role of GPA in both anabolic and catabolic amino acid metabolism by Entodinium caudatum.

scholarly journals Bioprocessing of Squid Pens Waste into Chitosanase by Paenibacillus sp. TKU047 and Its Application in Low-Molecular Weight Chitosan Oligosaccharides Production

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Trung Dung Tran ◽  
Anh Dzung Nguyen ◽  
...  
Keyword(s):  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Radical Scavenging ◽  
Maximum Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharide ◽  
Scavenging Activity ◽  
Paenibacillus Sp

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.

scholarly journals Immobilization of Aeromonas bivalvium PT2 Cells with Alginate and Measurement of Chitinolytic Activities

2020 ◽  
Vol 147 ◽  
pp. 03020
Author(s):  
Dita P. Saputri ◽  
Ustadi
Keyword(s):  
Bacterial Cell ◽  
Cell Immobilization ◽  
Chitinase Activity ◽  
Nutrient Broth ◽  
Chitinolytic Activity ◽  
Immobilized Bacteria ◽  
Chitinolytic Bacteria ◽  
Bacterial Immobilization ◽  
The Stability ◽  
Bacterial Cell Immobilization

Aeromonas bivalvium is one of the chitinolytic bacteria that able to degrade chitin into its derivatives. These bacteria can only be used once during the fermentation process, which is less profitable to be applied in industrial scale. This limitation can be solved by bacterial immobilization method. This study aimed to determine the effect of bacterial cell immobilization on chitinolytic activity and to determine the stability of the immobilized bacteria during repeated usage. Bacterial cell immobilization was carried out by entrapment method with 1% sodium alginate matrix. Immobilized bacteria was cultured in two different mediums, namely nutrient broth (NB) and nutrient broth (NB) added with colloidal chitin (NB + K). Tests for chitinolytic activity were carried out in bacteria. In addition, the stability of immobilized bacteria was also tested for chitinolytic activity with repeated removal and use. The result shows that the effectiveness of immobilization on average is 91.8%. Immobilization did not significantly affect chitinolytic activity when compared with bacteria without immobilization. Immobilized bacteria in this study has similar performance as bacteria without immobilization. The results of the stability tests including chitinase activity and NAG released indicated a significant decline during repeated usage with maximum usage of three times.

scholarly journals Comparative Genomics and Functional Studies of Wheat BED-NLR Loci

Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1406
Author(s):  
Clemence Marchal ◽  
Georg Haberer ◽  
Manuel Spannagl ◽  
Cristobal Uauy ◽  
Keyword(s):  
Cell Death ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Functional Studies ◽  
Network Analyses ◽  
Binding Factor ◽  
Localization Signal ◽  
Integrated Domains ◽  
Genomic Regions

Nucleotide-binding leucine-rich-repeat (LRR) receptors (NLRs) with non-canonical integrated domains (NLR-IDs) are widespread in plant genomes. Zinc-finger BED (named after the Drosophila proteins Boundary Element-Associated Factor and DNA Replication-related Element binding Factor, named BED hereafter) are among the most frequently found IDs. Five BED-NLRs conferring resistance against bacterial and fungal pathogens have been characterized. However, it is unknown whether BED-NLRs function in a manner similar to other NLR-IDs. Here, we used chromosome-level assemblies of wheat to explore the Yr7 and Yr5a genomic regions and show that, unlike known NLR-ID loci, there is no evidence for a NLR-partner in their vicinity. Using neighbor-network analyses, we observed that BED domains from BED-NLRs share more similarities with BED domains from single-BED proteins and from BED-containing proteins harboring domains that are conserved in transposases. We identified a nuclear localization signal (NLS) in Yr7, Yr5, and the other characterized BED-NLRs. We thus propose that this is a feature of BED-NLRs that confer resistance to plant pathogens. We show that the NLS was functional in truncated versions of the Yr7 protein when expressed in N. benthamiana. We did not observe cell-death upon the overexpression of Yr7 full-length, truncated, and ‘MHD’ variants in N. benthamiana. This suggests that either this system is not suitable to study BED-NLR signaling or that BED-NLRs require additional components to trigger cell death. These results define novel future directions to further understand the role of BED domains in BED-NLR mediated resistance.

scholarly journals Molecular Analysis of the Gene Encoding a Novel Chitin-Binding Protease from Alteromonas sp. Strain O-7 and Its Role in the Chitinolytic System

2002 ◽  
Vol 184 (7) ◽  
pp. 1865-1872 ◽  
Author(s):  
Katsushiro Miyamoto ◽  
Eiji Nukui ◽  
Hiroyuki Itoh ◽  
Takaji Sato ◽  
Takeshi Kobayashi ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Signal Sequence ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chitinase Activity ◽  
Maximum Activity ◽  
Sequencing Analysis ◽  
Gene Encoding ◽  
Calculated Molecular Mass ◽  
Chitin Binding Domain

ABSTRACT Alteromonas sp. strain O-7 secretes several proteins in response to chitin induction. We have found that one of these proteins, designated AprIV, is a novel chitin-binding protease involved in chitinolytic activity. The gene encoding AprIV (aprIV) was cloned in Escherichia coli. DNA sequencing analysis revealed that the open reading frame of aprIV encoded a protein of 547 amino acids with a calculated molecular mass of 57,104 Da. AprIV is a modular enzyme consisting of five domains: the signal sequence, the N-terminal proregion, the family A subtilase region, the polycystic kidney disease domain (PkdD), and the chitin-binding domain type 3 (ChtBD3). Expression plasmids coding for PkdD or both PkdD and ChtBD (PkdD-ChtBD) were constructed. The PkdD-ChtBD but not PkdD exhibited strong binding to α-chitin and β-chitin. Western and Northern analyses demonstrated that aprIV was induced in the presence of N-acetylglucosamine, N-acetylchitobiose, or chitin. Native AprIV was purified to homogeneity from Alteromonas sp. strain O-7 and characterized. The molecular mass of mature AprIV was estimated to be 44 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The optimum pH and temperature of AprIV were pH 11.5 and 35°C, respectively, and even at 10°C the enzyme showed 25% of the maximum activity. Pretreatment of native chitin with AprIV significantly promoted chitinase activity.

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