Search results for "Bacillus"
showing 10 items of 774 documents
Sinbiotiska produkta iegūšana, veicot no piena permeāta iegūta galaktooligosaharīdu (GOS) maisījuma selektīvu fermentāciju ar probiotiskiem celmiem
2022
Piena permeāts un tajā esošā laktoze kā substrāts var tikt izmantots ogļhidrātu biokonversijas pētījumos, kā arī dažādu mikroorganismu kultivēšanā, lai veidotu produktus ar pievienoto vērtību. Darba mērķis bija izvērtēt iespēju iegūt galaktooligosaharīdu (GOS) un pienskābo baktēriju saturošu sinbiotisku produktu, veicot selektīvu fermentāciju maisījumā, kas iegūts fermentatīvās GOS biosintēzes laikā no piena permeāta. Veicot fermentatīvu sintēzi ar ß-galaktozidāzēm, tika iegūts un aprakstīts GOS saturošs maisījums, kurā vēlāk tika veikta selektīva fermentācija ar probiotiskajiem Lactobacillus spp. celmiem, izvērtējot šo celmu ogļhidrātu preferences un izdzīvotību. Veicot fermentatīvu sintēz…
The influence of backslopping on lactic acid bacteria diversity in tarhana fermentation
2020
Tarhana is produced at batch systems in which the microbiota has changed accordingly to the microbial load from ingredients. In order to stabilize the microbiota, the effects of backslopping carried out under different temperature regimes (25 and 30 °C), pH (3.70 and 4.00) and inoculation rates (5, 10 and 15%) on lactic acid bacteria (LAB) diversity were determined in tarhana dough. LAB and Total Aerobic Mesophilic Bacteria (TAMB) numbers increased in all tarhana dough samples subjected to backslopping. Temperature and pH significantly affected the microbiological diversity of tarhana whereas the different inoculation rates did not. Tarhana dough showed complex tarhana microbiota following …
"In vitro" antagonism of a grapevine endophytic Bacillus subtilis strain towards "esca" fungi.
2008
Preliminary investigations on grapevines (CV Catarratto) with symptoms of “esca” permitted to isolate only bacterial colonies, from black punctuations belonging to the genus Bacillus. Particularly, an isolate was Gram-positive with spore forming and, on the basis of the partial 16S rRNA sequence comparison, it showed a similarity of 99% with Bacillus subtilis subsp. subtilis. There are numerous reports on the antagonistic activity of the species towards several phytopathogenic microorganisms. For this reason the possible bacterial control against the “esca” fungi (Phaeoacre- monium aleophilum, PAL; Phaemoniella clamidospora, PCH; Fomitiporia mediterranea, FOMED), was studied. The antagonist…
Studio su biologia, morfologia cellulare e immunità in Rhynchophorus ferrugineus (Olivier, 1970)
Complexation of Uranium by Cells and S-Layer Sheets of Bacillus sphaericus JG-A12
2005
ABSTRACT Bacillus sphaericus JG-A12 is a natural isolate recovered from a uranium mining waste pile near the town of Johanngeorgenstadt in Saxony, Germany. The cells of this strain are enveloped by a highly ordered crystalline proteinaceous surface layer (S-layer) possessing an ability to bind uranium and other heavy metals. Purified and recrystallized S-layer proteins were shown to be phosphorylated by phosphoprotein-specific staining, inductive coupled plasma mass spectrometry analysis, and a colorimetric method. We used extended X-ray absorption fine-structure (EXAFS) spectroscopy to determine the structural parameters of the uranium complexes formed by purified and recrystallized S-laye…
The genus thiobacillus: Physiology and industrial applications
1983
This review deals with different aspects concerning the genus Thiobacillus as an obligat chemoautotroph able to oxidize reduced anorganic sulphur compounds. There are given the following topics: physiology of the genus (nutritional requirements, enzymatic complexes for sulphur oxidation, energy generation, reductive CO2 assimilation and growing in presence of organic compounds). The ecological significance of Thiobacilli in the sulphur cycle in Nature is presented. The industrial applications of Thiobacilli in respect to the leaching processes that allow the recovery of metals through oxidation and solubilization from low-grade ores are discussed, with special reference to copper and uraniu…
The fnr Gene of Bacillus licheniformis and the Cysteine Ligands of the C-Terminal FeS Cluster
1998
Many of the O2-responsive gene regulators of bacteria are members of the fumarate nitrate reductase-cyclic AMP receptor protein family of transcriptional regulators (12, 13, 15, 17) with predicted structures similar to those of the cyclic AMP receptor protein (11). The Fnr (stands for fumarate nitrate reductase regulator) protein from Escherichia coli (FnrEc) controls the expression of a variety of genes, mainly of anaerobic respiration and metabolism (5, 13). It contains a N-terminal cluster of three essential cysteine residues which are supposed to bind together with Cys122 a [4Fe 4S]2+ cluster which is required for O2 sensing (4, 7, 8, 10, 16). A wide variety of gram-negative bacteria co…
Structural and functional diversity of Bacillus thuringiensis toxins on animal, plant and microbial cells
2018
Debido a los efectos nocivos de los insecticidas químicos en los ecosistemas y sobre los organismos beneficiosos, la implementación de agentes de control biológico ha recibido considerable atención. Entre los agentes de control biológico, se ha dedicado gran interés a los entomopatógenos, debido a su potencial para controlar plagas agrícolas y domésticas, vectores de enfermedades humanas y animales, sin introducir material no degradable en el medio ambiente. Bacillus thuringiensis (Bt) es el agente de control microbiano comercial más utilizado en la actualidad, con efectividad contra diferentes especies de insectos plaga. Las cepas de Bt producen cristales paraesporales proteináceos durante…
Dextransucrase Expression Is Concomitant with that of Replication and Maintenance Functions of the pMN1 Plasmid in
2017
The exopolysaccharide synthesized by Lactobacillus sakei MN1 is a dextran with antiviral and immunomodulatory properties of potential utility in aquaculture. In this work we have investigated the genetic basis of dextran production by this bacterium. Southern blot hybridization experiments demonstrated the plasmidic location of the dsrLS gene, which encodes the dextransucrase involved in dextran synthesis. DNA sequencing of the 11,126 kbp plasmid (pMN1) revealed that it belongs to a family which replicates by the theta mechanism, whose prototype is pUCL287. The plasmid comprises the origin of replication, repA, repB, and dsrLS genes, as well as seven open reading frames of uncharacterized f…
Estrategias biotecnológicas para reducir el contenido en fitatos en productos fermentados de origen vegetal mediante fitasas de bifidobacterias
2015
Los alimentos integrales de origen vegetal, concretamente, los cereales de grano entero y leguminosas se caracterizan por ser una fuente excelente de fibra dietética y poseer un elevado contenido en compuestos fitoquímicos. Además de proporcionar macronutrientes, como carbohidratos complejos y proteínas, también destacan por su contenido en micronutrientes como son las vitaminas y minerales. Sin embargo, su ingesta conlleva a la vez un aporte en sustancias antinutritivas, como los fitatos, con gran afinidad por minerales, proteínas y elementos traza, que pueden comprometer su absorción por formación de quelatos estables en el tracto digestivo. Una hidrólisis o defosforilación parcial de los…