Search results for "Bacillus"

An integrated technological approach to the selection of lactic acid bacteria of flour origin for sourdough production

2013

article i nfo Several lactic acid bacteria (LAB) were evaluated in situ for their potential in sourdough fermentation. The strains belonged to Lactobacillus plantarum, Lactobacillus sakei, Lactobacillus sanfranciscensis, Leuconostoc citreum, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides and Weissella cibaria. LAB were used, in individual inocula, to carry out the fermentation of γ-ray treated (sterile) flour and untreated commercial flour, in order to evaluate their performances both in the absence and presence of the native microbiota of flour. The pH and total titratable acidity (TTA) showed a strong and fast acidification of the experimental sourdough determined by W. cibari…

Determinazione di acidi linoleici coniugati (CLA) mediante Ag+-HPLC in latti fermentati da ceppi di Lactobacillus paracasei e Lactobacillus plantarum

2006

Rapid differentiation, in situ detection and monitoring of sourdough lactobacilli from the Abruzzo region (central Italy)

2006

Acidificación biológica de vinos de pH elevado mediante la utilización de bacterias lácticas

2014

Actualmente, se están observando las consecuencias del cambio climático en la vitivinivultura. En los últimos años se están generando cosechas más tempranas y uvas con una descompensación entre la madurez fenólica y la madurez industrial. Estas uvas generan mostos con una elevada concentración de azúcares y una baja concentración de ácidos, que dan lugar a vinos con una alta concentración de etanol, una baja AT y un elevado pH. Los vinos de pH elevado presentan varios inconvenientes. Son vinos planos y sin frescor, tienen una elevada inestabilidad microbiológica y generan una disminución en la capacidad antiséptica del anhídrido sulfuroso. El pH de los vinos puede descenderse mediante metod…

Potential exploitation of lysozyme in the winemaking of Sicilian wines from ???organic grapes"

2009

Lysozyme is a natural enzyme with muramidase activity which can work against a range of lactic acid bacteria (LAB), including Oenococcus, Pediococcus and Lactobacillus spp., that can affect wine stability (Cunningham et al., 1991). For such reason, over the last decade, there has been a growing interest in lysozyme as a supplement to sulphur dioxide for bacterial inhibition (Sonni et al., 2009). Since, lysozyme applications proved to be enough specific to require technical knowledge and expertise to be efficient, an experimental winemaking was performed to evaluate the efficiency of this enzyme application to produce a Sicilian wine from “organic grapes”. Specifically, two experimental cond…

Biodiversity and dairy traits of indigenous milk lactic acid bacteria grown in presence of the main grape polyphenols

2020

ABSTRACT The present work was developed to select lactic acid bacteria (LAB) to be used as starter cultures in functional cheese production. The indigenous milk LAB populations were isolated from fermented raw ewes’ milks (four bulks) added with 0.5 mg/mL of nine polyphenols commonly found in winery by-products. After 48 h of fermentation, all milks were characterized by an increase of LAB levels of about 3–4 Log cycles. All different colonies were purified and characterized for the main physiological and biochemical traits and then differentiated genetically at strain level and identified. Ten species belonging to the LAB genera Lactobacillus, Streptococcus, Enterococcus, Leuconostoc and L…

Monitoring of Bacillus Thuringiensis Cry3Aa Toxin Pore Formation using Artificial Bilayer Array with Fused Brush Border Membrane Vesicles from Colora…

2017

Hymenopteran specificity of Bacillus thuringiensis strain PS86Q3

2008

Abstract The biological activity of Bacillus thuringiensis (Bt) strain PS86Q3 against five Hymenopteran species was determined by means of bioassays adapted to each species. Four species of sawfly that are important pests of conifers (Diprion pini, Gilpinia hercyniae and Pristiphora abietina) or ornamental plants (Arge rosae), as well as the non-target honeybee, Apis mellifera, were studied. Two out of the four sawfly species tested were found to be sensitive to PS86Q3 crystals or spore/crystal suspensions. A sporulated culture of this strain was moderately active on D. pini, and a complete bioassay with solubilized crystals was performed to estimate the LC50 of 4.9 mg/ml. Pristiphora abiet…

Study of the bacillus thuringiensis Cry1Ia protein oligomerization promoted by midgut brush border membrane vesicles of lepidopteran and coleopteran …

2020

Bacillus thuringiensis (Bt) produces insecticidal proteins that are either secreted during the vegetative growth phase or accumulated in the crystal inclusions (Cry proteins) in the stationary phase. Cry1I proteins share the three domain (3D) structure typical of crystal proteins but are secreted to the media early in the stationary growth phase. In the generally accepted mode of action of 3D Cry proteins (sequential binding model), the formation of an oligomer (tetramer) has been described as a major step, necessary for pore formation and subsequent toxicity. To know if this could be extended to Cry1I proteins, the formation of Cry1Ia oligomers was studied by Western blot, after the incuba…

Genetic and Biochemical Analysis of PadR-padC Promoter Interactions during the Phenolic Acid Stress Response in Bacillus subtilis 168

2011

ABSTRACT Bacillus subtilis 168 is resistant to phenolic acids by expression of an inducible enzyme, the phenolic acid decarboxylase (PadC), that decarboxylates these acids into less toxic vinyl derivatives. In the phenolic acid stress response (PASR), the repressor of padC , PadR, is inactivated by these acids. Inactivation of PadR is followed by a strong expression of padC . To elucidate the functional interaction between PadR and the padC promoter, we performed (i) footprinting assays to identify the region protected by PadR, (ii) electrophoretic mobility shift assays (EMSAs) with a modified padC promoter protected region to determine the interacting sequences, and (iii) random mutagenesi…