The Probiotic SF68 as a Potential Food Fermentation Microorganism for Safe Food Production.

Due to the reports describing virulent and multidrug resistant enterococci, their use has become a topic of controversy despite most of them being safe and commonly used in traditionally fermented foods worldwide. We have characterized SF68, a probiotic strain approved by the European Food Safety Authority (EFSA) for use in food and feed, and find that it has a remarkable potential in food fermentations. Genome analysis revealed the potential of SF68 to metabolize a multitude of carbohydrates, including lactose and sucrose, which was substantiated experimentally.

Scrutinizing a mutant with enhanced capacity for extracellular electron transfer reveals a unique role for a novel type-II NADH dehydrogenase.

a lactic acid bacterium used in food fermentations and commonly found in the human gut, is known to possess a fermentative metabolism. , however, has been demonstrated to transfer metabolically generated electrons to external electron acceptors, a process termed extracellular electron transfer (EET). Here, we investigated an mutant with an unusually high capacity for EET that was obtained in an adaptive laboratory evolution (ALE) experiment.

Superior anodic electro-fermentation by enhancing capacity for extracellular electron transfer.

Anodic electro-fermentation (AEF), where an anode replaces the terminal electron acceptor, shows great promise. Recently a Lactococcus lactis strain blocked in NAD regeneration was demonstrated to use ferricyanide as an alternative electron acceptor to support fast growth, but the need for high concentrations of this non-regenerated electron acceptor limits practical applications. To address this, growth of this L.

Simple & better - Accelerated cheese ripening using a mesophilic starter based on a single strain with superior autolytic properties.

In the manufacture of rennet-coagulated cheese, autolysis is a rate-limiting step for ripening. Previously, a highly autolytic and thermotolerant Lactococcus lactis strain, RD07, was generated, which in preliminary laboratory cheese trials demonstrated great potential as a cheese ripening accelerant. RD07 is proteinase positive (Prt) and capable of metabolizing citrate (Cit).

Transforming acid whey into a resource by selective removal of lactic acid and galactose using optimized food-grade microorganisms.

The presence of lactic acid and galactose makes spray drying of acid whey (AW) a significant challenge for the dairy industry. In this study, a novel approach is explored to remove these compounds, utilizing food-grade microorganisms. For removing lactic acid, Corynebacterium glutamicum was selected, which has an inherent ability to metabolize lactic acid but does so slowly.

Rewiring the respiratory pathway of Lactococcus lactis to enhance extracellular electron transfer.

Lactococcus lactis, a lactic acid bacterium with a typical fermentative metabolism, can also use oxygen as an extracellular electron acceptor. Here we demonstrate, for the first time, that L. lactis blocked in NAD regeneration can use the alternative electron acceptor ferricyanide to support growth.

Fermented butter aroma for plant-based applications.

Plant-based dairy alternatives are gaining increasing interest, e.g. alternatives to yoghurt, cheese, and butter.

Harnessing cross-resistance - Sustainable nisin production from low-value food side streams using a Lactococcus lactis mutant with higher nisin-resistance obtained after prolonged chlorhexidine exposure.

Nisin has a tendency to associate with the cell wall of the producing strain, which inhibits growth and lowers the ceiling for nisin production. With the premise that resistance to the cationic chlorhexidine could reduce nisin binding, variants with higher tolerance to this compound were isolated. One of the resistant isolates, AT0606, had doubled its resistance to nisin, and produced three times more free nisin, when cultured in shake flasks.

High-yield and plasmid-free biocatalytic production of 5-methylpyrazine-2-carboxylic acid by combinatorial genetic elements engineering and genome engineering of Escherichia coli.

5-Methylpyrazine-2-carboxylic acid (MPCA) is an important pharmaceutical intermediate and is used in the production of hypoglycemic agents and lipid-lowering drugs. This work aimed to develop a whole-cell biocatalytic process for the efficient synthesis of MPCA from 2, 5-dimethylpyrazine (DMP). Firstly, a whole-cell biocatalyst Escherichia coli strain was constructed by plasmid-based expression of xylene monooxygenase (XMO), benzyl alcohol dehydrogenase (BADH), and benzaldehyde dehydrogenase (BZDH) from Pseudomonas putida ATCC 33015, resulting in MPCA titer of 5.

Engineering the Substrate Transport and Cofactor Regeneration Systems for Enhancing 2'-Fucosyllactose Synthesis in .

Human milk oligosaccharides (HMOs) have been proven to be beneficial to infants' intestinal health and immune systems. 2'-Fucosyllactose (2'-FL) is the most abundant and thoroughly studied HMO and has been approved to be an additive of infant formula. How to construct efficient and safe microbial cell factories for the production of 2'-FL attracts increasing attention.