Getting value from the waste: recombinant production of a sweet protein by Lactococcus lactis grown on cheese whey

Abstract

BackgroundRecent biotechnological advancements have allowed for the adoption of Lactococcus lactis, a typical component of starter cultures used in food industry, as the host for the production of food-grade recombinant targets. Among several advantages, L. lactis has the important feature of growing on lactose, the main carbohydrate in milk and a majoritarian component of dairy wastes, such as cheese whey.ResultsWe have used recombinant L. lactis NZ9000 carrying the nisin inducible pNZ8148 vector to produce MNEI, a small sweet protein derived from monellin, with potential for food industry applications as a high intensity sweetener. We have been able to sustain this production using a medium based on the cheese whey from the production of ricotta cheese, with minimal pre-treatment of the waste. As a proof of concept, we have also tested these conditions for the production of MMP-9, a protein that had been previously successfully obtained from L. lactis cultures in standard growth conditions.ConclusionsOther than presenting a new system for the recombinant production of MNEI, more compliant with its potential applications in food industry, our results introduce a strategy to valorize dairy effluents through the synthesis of high added value recombinant proteins. Interestingly, the possibility of using this whey-derived medium relied greatly on the choice of the appropriate codon usage for the target gene. In fact, when a gene optimized for L. lactis was used, the production of MNEI proceeded with good yields. On the other hand, when an E. coli optimized gene was employed, protein synthesis was greatly reduced, to the point of being completely abated in the cheese whey-based medium. The production of MMP-9 was comparable to what observed in the reference conditions.Electronic supplementary materialThe online version of this article (10.1186/s12934-018-0974-z) contains supplementary material, which is available to authorized users.

Nevertheless, She Resisted – Role of the Environment on Listeria monocytogenes Sensitivity to Nisin Treatment in a Laboratory Cheese Model

“…We used a method previously described (Henderson et al, 2019) to make approximately 10 g miniature cheese at different pH (6.5, 6.0, or 5. For treated cheese, 50 mg Nisaplin TM (Danisco) was added to 600 mL of pasteurized, whole milk (equivalent to 2 µg/mL or 2 ppm nisin, since Nisaplin contains 2.5% nisin), prior to acidification, to ensure even distribution throughout the final product (Fowler and McCann, 1971). Immediately after cheese was made, it was surface inoculated with 100 µL of a stationary phase (OD 600 = 1.0) culture of L. monocytogenes for a target level of inoculation of approximately 10 7 cfu/g.…”

Engineering Biology to Construct Microbial Chassis for the Production of Difficult-to-Express Proteins

“…In particular, an L. lactis NZ9000 strain that incorporates nisK and nisR has been developed [58] and along with its derivatives, is in active use for recombinant protein expression [94]. This system, along with others, has been used to produce various prokaryotic as well as eukaryotic proteins of animal and plant origin [95][96][97], with disulfide bonds intact [98]. Of particular note, L. lactis expression system has been proven to be highly efficient in membrane protein expression, where the expressed membrane proteins are localized to the cytoplasmic membrane and the use of mild detergents can readily solubilize these membrane proteins [94].…”

Aggregation-prone peptides modulate activity of bovine interferon gamma released from naturally occurring protein nanoparticles

“…coli) may be related to the absence of C-terminal variants in this sample or the effect of the fused His-tag to the C-term although may also be attributable to other variables [66]. The protein obtained from the L. lactis expression system displayed less activity, which may be to differences in the production process among prokaryotic expression systems [67,68]. Once the activity assay was validated, the biological activity contained in the IFN- protein NPs produced in L. lactis was determined.…”