Microbial interactions shape cheese flavour formation.

Cheese fermentation and flavour formation are the result of complex biochemical reactions driven by the activity of multiple microorganisms. Here, we studied the roles of microbial interactions in flavour formation in a year-long Cheddar cheese making process, using a commercial starter culture containing Streptococcus thermophilus and Lactococcus strains. By using an experimental strategy whereby certain strains were left out from the starter culture, we show that S.

Development of Tyrosine Decarboxylase-Negative Strains of Lactobacillus curvatus by Classical Strain Improvement.

Biogenic amines have been widely studied because of their potential toxicity in fermented foods. Several lactic acid bacteria have the potential to decarboxylate the amino acid tyrosine to tyramine. In this work, we identified two strains of Lactobacillus curvatus, Lbc1 and Lbc2, endowed with the ability to produce tyramine, a metabolic feature that limits their application in starter cultures for fermented meat.

A framework for good biofilm reactor modeling practice (GBRMP).

A researcher or practitioner can employ a biofilm model to gain insight into what controls the performance of a biofilm process and for optimizing its performance. While a wide range of biofilm-modeling platforms is available, a good strategy is to choose the simplest model that includes sufficient components and processes to address the modeling goal. In most cases, a one-dimensional biofilm model provides the best balance, and good choices can range from hand-calculation analytical solutions, simple spreadsheets, and numerical-method platforms.

Quality of care for people with multimorbidity - a case series.

Background: Multimorbidity is becoming increasingly prevalent and presents challenges for healthcare providers and systems. Studies examining the relationship between multimorbidity and quality of care report mixed findings. The purpose of this study was to investigate quality of care for people with multimorbidity in the publicly funded healthcare system in Denmark.

Enhancing the Sweetness of Yoghurt through Metabolic Remodeling of Carbohydrate Metabolism in Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus.

Unlabelled: Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus are used in the fermentation of milk to produce yoghurt. These species normally metabolize only the glucose moiety of lactose, secreting galactose and producing lactic acid as the main metabolic end product.

The art of strain improvement of industrial lactic acid bacteria without the use of recombinant DNA technology.

The food industry is constantly striving to develop new products to fulfil the ever changing demands of consumers and the strict requirements of regulatory agencies. For foods based on microbial fermentation, this pushes the boundaries of microbial performance and requires the constant development of new starter cultures with novel properties. Since the use of ingredients in the food industry is tightly regulated and under close scrutiny by consumers, the use of recombinant DNA technology to improve microbial performance is currently not an option.

Biochemical and kinetic characterisation of a novel xylooligosaccharide-upregulated GH43 β-d-xylosidase/α-l-arabinofuranosidase (BXA43) from the probiotic Bifidobacterium animalis subsp. lactis BB-12.

The Bifidobacterium animalis subsp. lactis BB-12 gene BIF_00092, assigned to encode a β-d-xylosidase (BXA43) of glycoside hydrolase family 43 (GH43), was cloned with a C-terminal His-tag and expressed in Escherichia coli. BXA43 was purified to homogeneity from the cell lysate and found to be a dual-specificity exo-hydrolase active on para-nitrophenyl-β-d-xylopyranoside (pNPX), para-nitrophenyl-α-L-arabinofuranoside (pNPA), β-(1 → 4)-xylopyranosyl oligomers (XOS) of degree of polymerisation (DP) 2-4, and birchwood xylan.

Rethinking wastewater characterisation methods for activated sludge systems - a position paper.

Increasingly stringent effluent limits and an expanding scope of model system boundaries beyond activated sludge has led to new modelling objectives and consequently to new and often more detailed modelling concepts. Nearly three decades after the publication of Activated Sludge Model No1 (ASM1), the authors believe it is time to re-evaluate wastewater characterisation procedures and targets. The present position paper gives a brief overview of state-of-the-art methods and discusses newly developed measurement techniques on a conceptual level.

Lactobacillus delbrueckii subsp. jakobsenii subsp. nov., isolated from dolo wort, an alcoholic fermented beverage in Burkina Faso.

Lactobacillus delbrueckii is divided into five subspecies based on phenotypic and genotypic differences. A novel isolate, designated ZN7a-9(T), was isolated from malted sorghum wort used for making an alcoholic beverage (dolo) in Burkina Faso. The results of 16S rRNA gene sequencing, DNA-DNA hybridization and peptidoglycan cell-wall structure type analyses indicated that it belongs to the species L.

Draft Whole-Genome Sequence of Bacillus sonorensis Strain L12, a Source of Nonribosomal Lipopeptides.

The Bacillus sonorensis L12 draft genome sequence is approximately 4,647,754 bp in size with a G+C content of 45.2%. Over 86% of the genome contains protein-encoding genes, including several gene clusters for de novo biosynthesis of the nonribosomal lipopeptides iturin, bacitracin, and fengycin, which could mean that the strain exhibits antifungal effects.

Method to identify potential phosphorus rate-limiting conditions in post-denitrification biofilm reactors within systems designed for simultaneous low-level effluent nitrogen and phosphorus concentrations.

Water-quality standards requiring simultaneous low level effluent N and P concentrations are increasingly common in Europe and the United States of America. Moving bed biofilm reactors (MBBRs) and biologically active filters (BAFs) have been used as post-denitrification biofilm reactors in processes designed and operated for this purpose (Boltz et al., 2010a).

Antimicrobial susceptibility of Bacillus strains isolated from primary starters for African traditional bread production and characterization of the bacitracin operon and bacitracin biosynthesis.

Bacillus spp. are widely used as feed additives and probiotics. However, there is limited information on their resistance to various antibiotics, and there is a growing concern over the transfer of antibiotic resistance genes.

Genotypic characterization and safety assessment of lactic acid bacteria from indigenous African fermented food products.

Background: Indigenous fermented food products play an essential role in the diet of millions of Africans. Lactic acid bacteria (LAB) are among the predominant microbial species in African indigenous fermented food products and are used for different applications in the food and biotechnology industries. Numerous studies have described antimicrobial susceptibility profiles of LAB from different parts of the world.

The role of loading rate, backwashing, water and air velocities in an up-flow nitrifying tertiary filter.

The vertical distribution of nitrification performances in an up-flow biological aerated filter operated at tertiary nitrification stage is evaluated in this paper. Experimental data were collected from a semi-industrial pilot-plant under various operating conditions. The actual and the maximum nitrification rates were measured at different levels inside the up-flow biofilter.

Heterologous expression of glycoside hydrolase family 2 and 42 β-galactosidases of lactic acid bacteria in Lactococcus lactis.

This study characterized a glycoside hydrolase family 42 (GH42) β-galactosidase of Lactobacillus acidophilus (LacA) and compared lactose hydrolysis, hydrolysis of oNPG, pNPG and pNPG-analogues and galactooligosaccharides (GOSs) formation to GH2 β-galactosidases of Streptococcus thermophilus (LacZ type), Lactobacillus plantarum and Leuconostoc mesenteroides subsp. cremoris (both LacLM type). Beta-galactosidases were heterologously expressed in Lactococcus lactis using a p170 derived promoter; experiments were performed with L.

A biofiltration model for tertiary nitrification of municipal wastewaters.

The main objective of this work concerns the evaluation of the biological aerated filtration model found in GPS-X, which had never been evaluated with adequate data. This model is interesting since it integrates the physical and biological phenomena involved during filtration with a low complexity of use. The validation of the model parameters combines experimental and theoretical approaches.

The long and winding road from the research laboratory to industrial applications of lactic acid bacteria.

Research innovations are constantly occurring in universities, research institutions and industrial research laboratories. These are reported in the scientific literature and presented to the scientific community in various congresses and symposia as well as through direct contacts and collaborations. Conversion of these research results to industrially useful innovations is, however, considerably more complex than generally appreciated.

Transformation of Leuconostoc carnosum 4010 and evidence for natural competence of the organism.

Plasmid transformation in Leuconostoc carnosum 4010 was analyzed. A successful transformation protocol for L. carnosum was established by modifying an existing protocol for Lactococcus lactis.

Heat shock treatment increases the frequency of loss of an erythromycin resistance-encoding transposable element from the chromosome of Lactobacillus crispatus CHCC3692.

A 3,165-bp chromosomally integrated transposon, designatedTn3692, of the gram-positive strain Lactobacillus crispatus CHCC3692 contains an erm(B) gene conferring resistance to erythromycin at concentrations of up to 250 micrograms/ml. Loss of this resistance can occur spontaneously, but the rate is substantially increased by heat shock treatment. Heat shock treatment at 60 degrees C resulted in an almost 40-fold increase in the frequency of erythromycin-sensitive cells (erythromycin MIC, 0.