Search results for "fermentation"
showing 10 items of 746 documents
Paving the crossroad of biorefinery
2018
This thesis focuses on anaerobic digestion and, more specifically, on its role in biorefinery and on the dynamic behaviour of the underlying microbiomes. In recent decades, significant progress has been made in the field of anaerobic digestion. Innovative methods, especially highthroughput sequencing approaches, have allowed for a deeper understanding of biotechnologically relevant biocenosis. However, the exact behaviour of the relevant microbiomes under different conditions has not been thoroughly researched. In order to shed light on the diversity of the underlying biocenosis, this thesis compares multiple biogas production facilities in Germany. It also provides the first multi-OMICs ch…
Procédé de Liquéfaction, Saccharification et Fermentation Simultanée à Très Haute Gravité utilisant de la farine de manioc pour la production de l'ét…
2021
A simultaneous liquefaction, saccharification and fermentation (SLSF) process at very high gravity of cassava flour for potable ethanol production was developed at lab (1 L) and pilot scale (15 L and 1000 L). Cassava flour (CF) was mixed with tap water to obtain a concentration of 270 g/L dry matter. Sequentially, the mixture of a native starch hydrolyzing enzyme containing a mixture of alpha–amylase and gluco-amylase (Stargen 002 at 2565 GAU/kg CF), gluco-amylase (Amigase Mega L at 0.105% w/w), active dry yeast Saccharomyces cerevisiae (Red Ethanol at 3,5 × 10^7 cells/ml), KH2PO4 (9,9 mM) and urea (16.0 mM) was added into cassava slurry. The SLSF-VHG process including three steps of liquef…
Tropical traditional fermented food, a field full of promise. Examples from the Tropical Bioresources and Biotechnology programme and other related F…
2013
International audience; In tropical countries, traditional fermented foods are usually home‐made products obtained through spontaneous fermentation or backslopping. They are now facing an evolution aiming at responding to quality, safety and mass production issues. This requires acquisition of knowledge on raw materials, microbial ecosystems and fermentation processes. Vietnam is a laboratory for such studies as traditional fermented foods play an important role in the diet of Vietnamese and as these foods are very diverse. Among the most popular are nem chua (sausage reminding Thai Nham), dua muoi (cabbage reminding Kimchi), tom chua (shrimps) and the well‐known nuoc mam. The challenge for…
Use and limitations of ICP-OES in wine analysis
1989
At present, some 50 inorganic components in wine can be detected, of which 8 are mineral matter at concentrations down to 1 mg/l, about 25 are trace elements with concentrations of 0.001–0.1 mg/l, and about 20 are ultratrace elements at concentrations below 1 μg/1. It has been shown that ICP-OES, a typical multielement detection method, permits the fast and reliable simultaneous determination of whole range of these inorganic species in wine, and thus can help in solving practical problems in wine manufacture. For instance, the metal content of wine can be checked, and corrosion and contamination monitored. Ten trace elements (Al, Cd, Co, Cr, Cu, Fe, Mn, Pb, V, Zn) which may be toxic or to …
Microbiological and Enological Parameters during Fermentation of Musts from Poor and Normal Grape-Harvests in the Region of Alicante (Spain)
1990
Must and wine from grapes harvested in two vintages (1986 and 1987) were anlyzed during vinification for physicochemical and microbiological characteristics. The 1986 vintage would be considered abnormal or poor vintage because of higher rainfall at harvest, and the 1987 one a normal vintage. Low reducing sugars and high volatile acidity at the beginning of the poor fermentation was observed as compared to normal vinification. The yeast population showed atypical evolution through the process since oxidative yeasts were isolated in the first stages of the poor vinification.
Evaluation of the variations in chemical and microbiological properties of the sourdoughs produced with selected lactic acid bacteria strains during …
2022
This research aimed to analyze variations in chemical properties, microbiological characteristics and generated volatile organic compounds (VOCs) profile during sourdough fermentation. Sourdoughs were collected from different cities in Turkey at two different times and lactic acid bacteria (LAB) in the samples were identified with culture-independent and culture-dependent molecular methods. According to culture-dependent methodology, thirteen LAB species were identified. Lactobacillus spp. were identified as the major group according to MiSeq Illumina analysis. Technological potential of commonly isolated LAB species was evaluated. Due to high frequency of isolation, Fructilactobacillus san…
Pyrosequencing vs. culture-dependent approaches to analyze lactic acid bacteria associated to chicha, a traditional maize-based fermented beverage fr…
2015
The diversity of lactic acid bacteria (LAB) associated with chicha, a traditional maize-based fermented alcoholicbeverage from Northwestern Argentina, was analyzed using culture-dependent and culture-independent approaches.Samples corresponding to 10 production steps were obtained from two local producers at Maimará(chicha M) and Tumbaya (chicha T). Whereas by culture-dependent approach a few number of species(Lactobacillus plantarum and Weissella viridescens in chicha M, and Enterococcus faecium and Leuconostocmesenteroides in chicha T) were identified, a higher quantitative distribution of taxa was found in both beveragesby pyrosequencing. The relative abundance of OTUs was higher in chic…
Persistence of a mixed lactic acid bacterial starter culture during lysine fortification of sourdough breads by addition of pistachio powder
2020
Abstract Pistachio powder was added to flour or semolina to evaluate its contribution to increase the amount of lysine in bread. Bread production was carried out by sourdough technology using a selected 3-species (Lactobacillus sanfranciscensis/Leuconostoc citreum/Weissella cibaria) lactic acid bacterial (LAB) starter culture. All sourdoughs were subjected to a long-time fermentation (21 h) and showed levels of LAB around 109 CFU/g, indicating the suitability of pistachio powder for lactic fermentation. Yeasts were also detected, in particular in semolina trials. MiSeq Illumina technology was applied to investigate the bacterial composition of sourdoughs evidencing a different distribution …
Characterization of sourdough lactic acid bacteria based on genotypic and cell-wall protein analyses
2003
Abstract Aims: To evaluate the effectiveness of two independent methods in differentiating a large population of lactic acid bacteria (LAB) isolated from wheat flours and sourdoughs and to correlate eventual differences/similarities among strains with their geographical origin and/or process parameters. Methods and Results: One hundred fifty strains belonging to Lactobacillus spp. and Weissella spp., plus eight type strains, one for each species, and two unidentified isolates, were characterized by randomly amplified polymorphic DNA (RAPD) and SDS-PAGE of cell-wall proteins. The RAPD analysis separated the eight type strains but did not always assign all the strains of a species to the same…
Exploring the yeast biodiversity of green table olive industrial fermentations for technological applications
2011
In recent years, there has been an increasing interest in identifying and characterizing the yeast populations associated with diverse types of table olive elaborations because of the many desirable technological properties of these microorganisms. In this work, a total of 199 yeast isolates were directly obtained from industrial green table olive fermentations and genetically identified by means of a RFLP analysis of the 5.8S-ITS region and sequencing of the D1/D2 domains of the 26S rDNA gene. Candida diddensiae, Saccharomyces cerevisiae and Pichia membranifaciens were the most abundant yeast species isolated from directly brined Aloreña olives, while for Gordal and Manzanilla cultivars th…