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Producing Vegan Probiotics: The Animal-Free Alternative to Dairy Peptones

In microbial culture, finding animal-free alternatives to dairy peptones is now a priority. The goal is to meet the growing demand for vegan probiotic products while ensuring optimal fermentation performance. In our interview with Benoît Drogue (PhD), Innovation Project Manager at Procelys by Lesaffre, we will explore the development of yeast peptones and their impact on microbial culture efficiency.

Benoit drogue

Innovation Project Manager

Why this study and what are you looking to achieve with the study?

Benoit Drogue: Our study aimed to consider the growing trend in the probiotics market (especially with Lactobacilli and Bifidobacteria) to offer products that can be claimed to be “vegan.” For this, the bacteria must be produced in a culture medium without any animal-derived elements. In the industrial context, the use of casein peptones or milk derivatives, milk proteins, or whey for bacterial growth is common. One of the biggest challenges for the probiotics industry currently is to replace animal-based nitrogen sources. Plant-based alternatives also have their limitations. Soy, pea, and wheat peptones for example are not gluten or allergen-free. In this context, yeast peptones are emerging as a promising solution.

Learn more about how we can support with dairy-free and animal-free culture media for industrial-scale production of Bifidobacterium

Why are peptones particularly interesting in the probiotics production?

Benoît Drogue: Peptones are an important source of nitrogen easily assimilated by lactic acid bacteria. They are partially hydrolyzed proteins in the form of a liquid, paste, powder, or granules. From an industrial perspective, they are key components for the development and production of active and resistant probiotics.  

This is the case with Bifidobacterium longum, a species of lactic acid bacteria from the Bifidobacteriaceae family, found in the human and pig digestive tracts. Although not dominant, it is a commensal organism of the human digestive tract and vagina, where it inhibits the growth of pathogenic bacteria and stimulates the immune system. Several strains have been selected for their probiotic effects.

What methodology did you prefer in this study?

Benoît Drogue: This evaluation followed the development of an innovative yeast peptone optimized for the production of Bifidobacterium: NuCel® 789 MG. In this study, we compared our optimized NuCel® 789 MG peptone, to other types of peptones, including a rice peptone, a casein peptone, and another yeast peptone. The goal was to determine if yeast peptones could achieve the same level of performance as the peptones currently available on the market, or even surpass them.

We wanted to focus on specific bacteria, especially certain Bifidobacteria, which are more delicate to cultivate. Our new product specifically targets applications related to Bifidobacterium, including different species like Bifidobacterium animalis subsp. lactis DSM 10140. The main objective was to empirically compare the performance of other types of peptones to NuCel® 789 MG.

What are the main results?

Benoît Drogue: Overall, we found that our product was effective across a wide range of Bifidobacterium compared to milk casein. Of course, depending on the strains, some optimizations may be necessary, but overall, our product works well.

Additionally, NuCel® 789 MG was beneficial for the growth and viability of other Bifidobacterium species.

If we look at rice peptones, for example, they are considerably lower in terms of performance. From a microbial nutrition standpoint, this peptone does not meet the required needs. That’s why it is interesting to have yeast-derived peptones.

In this study, you focus on optimizing yeast peptones, why?

Benoît Drogue: Each strain has specific nutritional needs, and each fraction of yeast peptones must be able to meet these needs. And that’s precisely what our study illustrates: compared to a standard yeast peptone, NuCel® 789 MG promotes better bacterial growth.

This effect is measured in terms of:

  • biomass
  • viability
  • cellular vitality


This point is crucial because the effectiveness of a probiotic depends on the sufficient presence of active cells in the body. Optimizing the composition and manufacturing process of the peptone is therefore essential to guarantee the industrial performance of fermentation. This study demonstrates that at an equivalent level of biomass at the reactor outlet, the condition containing NuCel® 789 MG contains significantly more active bacterial cells than traditional yeast, rice, or casein peptones while maintaining optimal growth kinetics.

What conclusions can be drawn from this study?

Benoît Drogue: Yeast peptones can be an effective animal-free alternative to casein and rice peptones. Furthermore, this study demonstrates our expertise in optimizing the composition of yeast-based ingredients. Formula characterization is essential for industrial performance to ensure better viability of the probiotic strain or family of probiotic strains. At Procelys, we help our clients understand and meet the needs of their microorganisms by optimizing the performance of their culture media.