Here, we present the draft genome of Lactococcus raffinolactis strain 4877, isolated from a natural mesophilic dairy starter culture. The nonstarter lactic acid bacterium Lactococcus raffinolactis is prevalent in a wide range of environments, such as the dairy environment, but little is known about this species. Genome Sequence of Lactococcus raffinolactis Strain 4877, Isolated from Natural Dairy Starter Culture The usefulness of this system is demonstrated by overexpressing the pepN gene in a number of industrial backgrounds. Importantly, the presence of this vector in a variety of industrial strains has no significant effect on the growth rate or the rate of acidification in milk, making this an ideal system for food-grade modification of industrially relevant L. Using suppressible pyrimidine auxotrophs, selection and maintenance are efficient in any pyrimidine-free medium including milk. The vector uses an amber suppressor, supD, as selectable marker and consists entirely of Lactococcus DNA, with the exception of a small polylinker region. Here, we report the development of a new food-grade cloning vector, pFG200, which is suitable for overexpressing a variety of genes in industrial strains of Lactococcus lactis. As supB suppresses both amber and ochre stop codons, which are present in 82% of all known lactococcal genes, this undesirable finding may result from the accumulation of elongated mistranslated polypeptides. This vector, pFG1, causes only a slight growth inhibition in the laboratory strain MG1363 but is unstable in the industrial strains tested. We have previously reported the construction of a food-grade cloning vector for Lactococcus using the ochre suppressor, supB, as the selective marker. Larsen, Rasmus Kibenich, Annette Junge, Mette P. lactis 470Ch2) was selected as autochthonous starter culture for industrial Valdeteja goat cheese manufacturing.Ī Food-Grade Cloning System for Industrial Strains of Lactococcus lactis
An F strain acetoin producer ( Lactococcus lactis subsp. Significant (P < 0.001) differences between titrable acidity of F and S strains were observed after the second hour of incubation. The kinetic parameters (lag phase, maximum acid production rate and value of upper asymptote curve) of the acid production curves for F and S strains were significantly (P < 0.001) different. The strains were divided into two groups depending on the acid production rate: 20 fast acid producer (F) strains and 25 slow acid producer (S) strains. lactis strains isolated from a home-made batch of Valdeteja cheese with excellent sensory characteristics was measured over a period of 18 h. The titrable acidity of 45 Lactococcus lactis subsp.
lactis strains isolated from goat's milk and goat cheese (Valdeteja variety) in order to select a suitable starter culture for industrial goat cheese manufacturing. This work was carried out to study the acid production by Lactococcus lactis subsp. lactis strains isolated from goat's milk and Valdeteja cheese.Īlonso-Calleja, C Carballo, J Capita, R Bernardo, A GarcÃa-López, M L Comparison of the acidifying activity of Lactococcus lactis subsp.