scholarly journals STUDY OF CHITINASE AND CHITINOLYTIC ACTIVITY OF LACTOBACILLUS STRAINS

2020 ◽  
Vol 49 (2) ◽  
pp. 214-224
Author(s):  
E. Horvath-Szanics ◽  
J. Perjéssy ◽  
A. Klupács ◽  
K. Takács ◽  
A. Nagy ◽  
...  
Keyword(s):  
Plant Material ◽  
Protein Production ◽  
Chitinase Activity ◽  
Natural Food ◽  
Chitinolytic Activity ◽  
Chitinolytic Enzymes ◽  
Chemical Preservative ◽  
Major Structural Component ◽  
Genes Encoding ◽  
Natural Microflora

The increasing consumer demand for less processed and more natural food products – while improving those products’ quality, safety, and shelf-life – has raised the necessity of chemical preservative replacement. Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Chitinolytic enzymes are of biotechnological interest, since their substrate, chitin, is a major structural component of the cell wall of fungi, which are the main cause of the spoilage of food and raw plant material. Among the several organisms, many bacteria produce chitinolytic enzymes, however, this behaviour is not general. The chitinase activity of the lactic acid bacteria is scarcely known and studied.The aim of the present study was to select Lactobacillus strains that have genes encoding chitinase, furthermore, to detect expressed enzymes and to characterise their chitinase activity. Taking into consideration the importance of chitin-bindig proteins (CBPs) in the chitinase activity, CBPs were also examined. Five Lactobacillus strains out of 43 strains from 12 different species were selected by their chitinase coding gene. The presence of the chitinase and chitin-biding protein production were confirmed, however, no chitinolytic activity has been identified.

Effect of nonthermal treatments on selected natural food pigments and color changes in plant material

2021 ◽  
Author(s):  
Małgorzata Nowacka ◽  
Magdalena Dadan ◽  
Monika Janowicz ◽  
Artur Wiktor ◽  
Dorota Witrowa‐Rajchert ◽  
...  
Keyword(s):  
Plant Material ◽  
Natural Food ◽  
Color Changes

Endophytic Bacteria of Cotton and Sweet Corn for Providing Growth Promotion and Biological Disease Control

1996 ◽  
Author(s):  
Joseph W. Kloepper ◽  
Ilan Chet
Keyword(s):  
Seed Treatment ◽  
Protein Production ◽  
Sweet Corn ◽  
Growth Promotion ◽  
Sclerotium Rolfsii ◽  
Chitinolytic Enzymes ◽  
Low Concentrations ◽  
Bacillus Spp ◽  
Biological Control Potential

Endophytes were isolated from 16.7% of surface-disinfested seeds and 100% of stems and roots of field-growth plants. Strains from Israel with broad-spectrum in vitro antibiosis were mainly Bacillus spp., and some were chitinolytic. Following dipping of cut cotton roots into suspensions of these strains, endophytes were detected up to 72 days later by isolation and by autoradiograms of 14C-labelled bacteria. Selected endophytes exhibited biological control potential based on significant reductions in disease severity on cotton inoculated with Rhizoctonia solani or Fusarium oxysporum f. sp. vasinfectum as well as control of Sclerotium rolfsii on bean. Neither salicylic acid nor chitinase levels increased in plants as a result of endophytic colonization, suggesting that the observed biocontrol was not accounted for by PR protein production. Some biocontrol endophytes secreted chitinolytic enzymes. Model endophytic strains inoculated into cotton stems via stem injection showed only limited movement within the stem. When introduced into stems at low concentrations, endophytes increased in population density at the injection site. After examining several experimental and semi-practical inoculation systems, seed treatment was selected as an efficient way to reintroduce most endophytes into plants.

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.

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 Secretion of Human Serum Albumin by Kluyveromyces lactis Overexpressing KlPDI1 and KlERO1

2005 ◽  
Vol 71 (8) ◽  
pp. 4359-4363 ◽  
Author(s):  
Tiziana Lodi ◽  
Barbara Neglia ◽  
Claudia Donnini
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Protein Conformation ◽  
Protein Production ◽  
Heterologous Protein ◽  
Kluyveromyces Lactis ◽  
Heterologous Proteins ◽  
Disulfide Bridges ◽  
Genes Encoding

ABSTRACT The control of protein conformation during translocation through the endoplasmic reticulum is often a bottleneck for heterologous protein production. The core pathway of the oxidative folding machinery includes two conserved proteins: Pdi1p and Ero1p. We increased the dosage of the genes encoding these proteins in the yeast Kluyveromyces lactis and evaluated the secretion of heterologous proteins. KlERO1, an orthologue of Saccharomyces cerevisiae ERO1, was cloned by functional complementation of the ts phenotype of an Scero1 mutant. The expression of KlERO1 was induced by treatment of the cells with dithiothreitol and by overexpression of human serum albumin (HSA), a disulfide bond-rich protein. Duplication of either PDI1 or ERO1 led to a similar increase in HSA yield. Duplication of both genes accelerated the secretion of HSA and improved cell growth rate and yield. Increasing the dosage of KlERO1 did not affect the production of human interleukin 1β, a protein that has no disulfide bridges. The results confirm that the ERO1 genes of S. cerevisiae and K. lactis are functionally similar even though portions of their coding sequence are quite different and the phenotypes of mutants overexpressing the genes differ. The marked effects of KlERO1 copy number on the expression of heterologous proteins with a high number of disulfide bridges suggests that control of KlERO1 and KlPDI1 is important for the production of high levels of heterologous proteins of this type.

scholarly journals Global Transcriptomic Analysis Reveals Insights into the Response of ‘Etrog’ Citron (Citrus medica L.) to Citrus Exocortis Viroid Infection

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 453 ◽  
Author(s):  
Yafei Wang ◽  
Jiaxing Wu ◽  
Yuanjian Qiu ◽  
Sagheer Atta ◽  
Changyong Zhou ◽  
...  
Keyword(s):  
Rna Silencing ◽  
Feedback Regulation ◽  
Defense Responses ◽  
Chitinase Activity ◽  
Regulation Mechanism ◽  
Argonaute 2 ◽  
Citrus Exocortis Viroid ◽  
Viroid Infection ◽  
Genes Encoding ◽  
Rna Polymerase 1

Citrus exocortis viroid (CEVd) is the causal agent of citrus exocortis disease. We employed CEVd-infected ‘Etrog’ citron as a system to study the feedback regulation mechanism using transcriptome analysis in this study. Three months after CEVd infection, the transcriptome of fresh leaves was analyzed, and 1530 differentially expressed genes were detected. The replication of CEVd in citron induced upregulation of genes encoding key proteins that were involved in the RNA silencing pathway such as Dicer-like 2, RNA-dependent RNA polymerase 1, argonaute 2, argonaute 7, and silencing defective 3, as well as those genes encoding proteins that are related to basic defense responses. Many genes involved in secondary metabolite biosynthesis and chitinase activity were upregulated, whereas other genes related to cell wall and phytohormone signal transduction were downregulated. Moreover, genes encoding disease resistance proteins, pathogenicity-related proteins, and heat shock cognate 70 kDa proteins were also upregulated in response to CEVd infection. These results suggest that basic defense and RNA silencing mechanisms are activated by CEVd infection, and this information improves our understanding of the pathogenesis of viroids in woody plants.

scholarly journals The mechanical impact of col11a2 loss on joints; col11a2 mutant zebrafish show changes to joint development and function, which leads to early-onset osteoarthritis

2018 ◽  
Vol 373 (1759) ◽  
pp. 20170335 ◽  
Author(s):  
Elizabeth A. Lawrence ◽  
Erika Kague ◽  
Jessye A. Aggleton ◽  
Robert L. Harniman ◽  
Karen A. Roddy ◽  
...  
Keyword(s):  
Early Onset ◽  
Mechanical Performance ◽  
Bone Development ◽  
Type Ii Collagen ◽  
Cell Behaviour ◽  
Major Structural Component ◽  
Genes Encoding ◽  
Type Xi Collagen ◽  
And Function ◽  
The Impact

Collagen is the major structural component of cartilage, and mutations in the genes encoding type XI collagen are associated with severe skeletal dysplasias (fibrochondrogenesis and Stickler syndrome) and early-onset osteoarthritis (OA). The impact of the lack of type XI collagen on cell behaviour and mechanical performance during skeleton development is unknown. We studied a zebrafish mutant for col11a2 and evaluated cartilage, bone development and mechanical properties to address this. We show that in col11a2 mutants, type II collagen is made but is prematurely degraded in maturing cartilage and ectopically expressed in the joint. These changes are correlated with increased stiffness of both bone and cartilage; quantified using atomic force microscopy. In the mutants, the skeletal rudiment terminal region in the jaw joint is broader and the interzone smaller. These differences in shape and material properties impact on joint function and mechanical performance, which we modelled using finite element analyses. Finally, we show that col11a2 heterozygous carriers reach adulthood but show signs of severe early-onset OA. Taken together, our data demonstrate a key role for type XI collagen in maintaining the properties of cartilage matrix; which when lost leads to alterations to cell behaviour that give rise to joint pathologies. This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

CRABTREE POZİTİF VE CRABTREE NEGATİF MAYA TÜRLERİNDE GCR1 GENİNİN IN SILICO ANALİZİ

2021 ◽  
Vol 8 (17) ◽  
pp. 207-216
Author(s):  
Tülay TURGUT GENÇ ◽  
Ataberk ÇAKAN ◽  
Melih GÜNAY
Keyword(s):  
In Silico ◽  
Protein Production ◽  
Heterologous Protein ◽  
Yeast Species ◽  
Yeast Cells ◽  
Crabtree Effect ◽  
Promoter Regions ◽  
Yeast Strains ◽  
Genes Encoding ◽  
Chromatin Folding

The use of fermentation in the presence of oxygen and at high glucose concentrations is referred to as the Crabtree effect. Yeast species that have the Crabtree effect are called Crabtree positive, and yeast species that do not have the Crabtree effect are called Crabtree negative. While Crabtree negative yeast strains are mostly used for heterologous protein production in the industrial field, Crabtree positive yeast strains are used to understand metabolic events in cancer cells. The genes encoding the enzymes involved in the glycolytic pathway in S. cerevisiae yeast cells are controlled by Gcr1p. Gcr1p binds to CT elements located in the promoter regions of glycolytic genes and activates their transcription. In our study, Crabtree positive and negative yeast strains containing Sc-Gcr1p similar proteins were determined, and protein similarity analyzes and promoter analyzes of genes encoding the relevant proteins in these yeast strains were compared in silico using different databases and analysis programs. For this purpose, SGD, UNIPROT, NCBI-Genome and Yeastract databases and BLASTp-NCBI, MEGA-X and Chromatin Folding V2 programs were used. Using the SGD database, 32 different yeast strains were identified that matched with Sc-Gcr1p. Five different Crabtree positive and 5 different Crabtree negative yeast strains were selected from these yeast strains and in silico analyzes were performed using these yeast strains. After protein analysis and promoter analysis, it was determined that the similarities and differences between yeast species were not specific for Crabtree positive and Crabtree negative yeast species, but varied between species.

scholarly journals Chitin Hydrolysis by Listeria spp., Including L. monocytogenes

2008 ◽  
Vol 74 (12) ◽  
pp. 3823-3830 ◽  
Author(s):  
J. J. Leisner ◽  
M. H. Larsen ◽  
R. L. Jørgensen ◽  
L. Brøndsted ◽  
L. E. Thomsen ◽  
...  
Keyword(s):  
Food Processing ◽  
Cell Walls ◽  
Chitinolytic Activity ◽  
Gene Encoding ◽  
Carbon And Nitrogen ◽  
Food Borne ◽  
Genes Encoding ◽  
Processing Plants ◽  
Chitin Hydrolysis ◽  
Chitin Binding Protein

ABSTRACT Listeria spp., including the food-borne pathogen Listeria monocytogenes, are ubiquitous microorganisms in the environment and thus are difficult to exclude from food processing plants. The factors that contribute to their multiplication and survival in nature are not well understood, but the ability to catabolize various carbohydrates is likely to be very important. One major source of carbon and nitrogen in nature is chitin, an insoluble linear β-1,4-linked polymer of N-acetylglucosamine (GlcNAc). Chitin is found in cell walls of fungi and certain algae, in the cuticles of arthropods, and in shells and radulae of molluscs. In the present study, we demonstrated that L. monocytogenes and other Listeria spp. are able to hydrolyze α-chitin. The chitinolytic activity is repressed by the presence of glucose in the medium, suggesting that chitinolytic activity is subjected to catabolite repression. Activity is also regulated by temperature and is higher at 30°C than at 37°C. In L. monocytogenes EGD, chitin hydrolysis depends on genes encoding two chitinases, lmo0105 (chiB) and lmo1883 (chiA), but not on a gene encoding a putative chitin binding protein (lmo2467). The chiB and chiA genes are phylogenetically related to various well-characterized chitinases. The potential biological implications of chitinolytic activity of Listeria are discussed.

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