Search results for "actic acid"
showing 10 items of 660 documents
Lowering histamine formation in a red Ribera del Duero wine (Spain) by using an indigenous O. oeni strain as a malolactic starter
2016
This study demonstrates for the first time that a non-commercial selected autochthonous O. oeni strain has been used to conduct malolactic fermentation (MLF) while lowering histamine formation in the same winery. Lactic acid bacteria (LAB) were isolated from 13 vats before and after spontaneous MLF at the Pago de Carraovejas winery from the Ribera del Duero region (Spain). Only O. oeni were present, typed and characterized, and both histamine producer and non-producers existed. From the non-producers, one strain was selected to become a starter according to its genetic profile, prevalence in the different wines in the winery, resistance to alcoholic degree, resistance to high polyphenolic c…
Improvement of osteogenic differentiation of human mesenchymal stem cells on composite poly l-lactic acid/nano-hydroxyapatite scaffolds for bone defe…
2020
Tissue engineering offers new approaches to repair bone defects, which cannot be repaired physiologically, developing scaffolds that mimic bone tissue architecture. Furthermore, biomechanical stimulation induced by bioreactor, provides biomechanical cues that regulate a wide range of cellular events especially required for cellular differentiation and function. The improvement of human mesenchymal stem cells (hMSCs) colonization in poly-L-lactic-acid (PLLA)/nano- hydroxyapatite (nHA) composite scaffold was evaluated in terms of cell proliferation (dsDNA content), bone differen- tiation (gene expression and protein synthesis) and ultrastructural analysis by comparing static (s3D) and dynamic…
Isolation of acetic, propionic and butyric acid-forming bacteria from biogas plants.
2015
In this study, acetic, propionic and butyric acid-forming bacteria were isolated from thermophilic and mesophilic biogas plants (BGP) located in Germany. The fermenters were fed with maize silage and cattle or swine manure. Furthermore, pressurized laboratory fermenters digesting maize silage were sampled. Enrichment cultures for the isolation of acid-forming bacteria were grown in minimal medium supplemented with one of the following carbon sources: Na(+)-dl-lactate, succinate, ethanol, glycerol, glucose or a mixture of amino acids. These substrates could be converted by the isolates to acetic, propionic or butyric acid. In total, 49 isolates were obtained, which belonged to the phyla Firm…
Recent advancements in lactic acid production - a review.
2017
Abstract Lactic acid, as an organic acid, has essential roles in industrial applications ranging from the food industry to life-sciences. Conventional fermentation methods have been well-studied since late 18th century, but are unable to achieve consumers' expectations regarding both quality and quantity. Therefore, novel technological developments of lactic acid production to increase yield and decrease over-all cost have become the primary goal. Genetic and metabolic engineering are great tools to overcome problems associated with product inhibition, undesired by-product formation, the negative effect of extreme culture conditions and most importantly inefficient use of expensive substrat…
Noise elicits hematological stress parameters in Mediterranean damselfish (Chromis chromis, perciformes): A mesocosm study
2017
In the last few decades, technological developments and the widespread rise of anthropic activities have increased the exposure of organisms to noise pollution, thus evoking great interest in its biological effects, particularly on the immune system. The aim of the present work was to investigate some of the biochemical parameters in the blood of Chromis chromis (Linnaeus, 1758) following in vivo exposure to noise levels of 200 and 300 Hz. Our results revealed that, compared to the control specimens, the fish exposed to noise had significantly increased levels of stress biomarkers such as glucose, lactate and total proteins in plasma, as well as a rise in the expression of heat shock protei…
Prebiotic effect of xylooligosaccharides produced from birchwood xylan by a novel fungal GH11 xylanase.
2017
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Influence of salt of different origin on the microbiological characteristics, histamine generation and volatile profile of salted anchovies (Engrauli…
2018
Abstract The effect of six salts of different geographical areas on the quality of salted anchovies was evaluated. The crude salts were chemically characterized by determination of inorganic and volatile organic compounds (VOCs). Salted anchovies, corresponding to six experimental trials, were subjected to microbiological, chemical (including histamine content) and sensory analysis during the entire period of ripening (150 days). The salts were characterized by marked differences in terms of major cations and trace element amounts. Among the 27 VOCs detected, octadecane was the most abundant compound and the main differences of the salts were registered for alkanes and alcohols. During matu…
Selection of Lactobacillus strains to induce biological acidification in low acidity wines
2016
Abstract Because of global warming, wines are obtained nowadays with high pH values and low acidity. This results in wines with disturbed flavor and increased susceptibility of microbial spoilage. The aim of this work was the selection of Lactobacillus strains with ability to induce biological acidification in low acidity grape musts to obtain more acidic wines. A screening of Lactobacillus strains was carried out using several selection criteria. Lactobacillus strains that grew in must, carried out the malolactic fermentation, acidified grape must, synthesized lactic acid from sugars, and showed high resistance to lysozyme and sulfur dioxide were selected. Selected strains were characteriz…
Valorisation of Dairy Wastes Through Kefir Grain Production
2019
The main aim of this work was to investigate on kefir grains (KGs) increase using different dairy by-products. To this purpose, whey and deproteinized whey from cow, goat and sheep milk were compared to the pasteurized milk of the corresponding animal species. Each substrate was inoculated with 3% (w/v) of KGs cultivated in ultra-high temperature cow milk and evalu- ated for pH decrease, total titratable acidity increase and development of lactic acid bacteria (LAB) and yeasts released in the matrices after 24 h incubation at three different temperatures (20, 25 and 30 °C). The genotypic characterization of the dominating microbial populations resulted in the identification of two LAB belon…
Improvement of Raw Milk Cheese Hygiene through the Selection of Starter and Non-Starter Lactic Acid Bacteria: The Successful Case of PDO Pecorino Sic…
2021
This review article focuses on the technological aspects and microbiological critical points of pressed-cooked cheeses processed from raw ewe’s milk without the inoculation of starter cultures, in particular “Pecorino” cheese typology produced in Italy. After showing the composition of the biofilms adhering to the surface of the traditional dairy equipment (mainly wooden vat used to collect milk) and the microbiological characteristics of PDO Pecorino Siciliano cheese manufactured throughout Sicily, this cheese is taken as a case study to develop a strategy to improve its hygienic and safety characteristics. Basically, the natural lactic acid bacterial populations of fresh and ripened chees…