The benefits of yeast-based biostimulants for crops

The yeast or yeasts?

The term “yeast” does not refer to a single species, but rather a group of species. More than 2,000 different wild species have been identified to date.
However, “yeast” can be used to describe baker’s yeast or brewer’s yeast: Saccharomyces cerevisiae, which is currently the most widely used in the fermentation industry and the most studied.

Did you know that the first proven use of yeast dates back to ancient Egypt? At that time, it was used for bread making, although its function was not known. Today, yeast is well understood and its uses range from the food, health, and wellness industries to agriculture, but are you familiar with its effects in biostimulation?

Yeast and derivatives

Yeast contains many compounds with numerous beneficial properties. These elements are varied in nature, including vitamins, amino acids, and hormones.

However, how can we reap their benefits?

We can obtain derivatives through various industrial processes, such as:

• Autolysis, which is the digestion of the cell wall by yeast enzymes. This process separates the cell wall from its internal contents.
• Fermentation is a complex metabolic mechanism in yeast that occurs both in the presence and absence of oxygen. Under anaerobic conditions, fermentation ensures the creation of energy through the consumption of sugars, which produces alcohol. But fermentation is also the process by which yeast multiplies in the presence of oxygen. It is through this process that yeast releases a variety of key compounds, such as amino acids, phytohormones, and other organic compounds.

What are the effects of yeast in biostimulation?

Once we have obtained these derivatives, how does it work?

Yeast-based biostimulants are characterized by a complex combination of elements that vary according to several parameters: the strain, the type of derivatives, the raw materials used, etc. Thus, the source of the effect of a yeast-based biostimulant depends on the composition of the solution. Depending on the concentration of hormones, amino acids, and vitamins present, the effects on the plant will not be the same. In biostimulation, we can identify three effects:  

• Limiting the impact of abiotic stress

• Stimulate plant metabolism

• Improving plant growth

Let’s take a closer look to understand how yeast works in biostimulation.

Fermentation metabolites and the fight against abiotic stress

First, we might ask ourselves why we should combat abiotic stress.
Quite simply because global warming increases the frequency of these abiotic stresses, to such an extent that today, more than three-quarters of crops are affected by them every year, and these stresses can cause up to 50% yield losses. But how can we deal with this?

Biostimulants based on yeast fermentation metabolites are rich in hormones, amino acids, and other organic compounds that have a direct effect on the plant’s response to these stresses. They have several actions:

• Optimize energy metabolism by maintaining photosynthetic activity and thus plant nutrition.

• Promote the synthesis of antioxidants and the concentration of osmoprotectants by the plant, limiting water loss through transpiration from cells and leaves.

These combined actions limit the senescence of the plant’s organs, particularly during flowering, thereby maintaining yields.

Yeast extracts: promising growth and quality

Biostimulants based on yeast extracts have a different action thanks to their composition. Rich in amino acids and vitamins, they provide plants with nutrients that promote energy and metabolic balance. These biostimulants regulate the expression of different metabolic pathways, optimizing fruit development:  

• Improving their growth

• Homogenizing their maturation

• Increasing their quality

Yeast autolysates and yield optimization

Biostimulants based on yeast autolysates have a combined effect on plants, boosting yields. The combination of vitamins, amino acids, and hormones naturally produced by yeast optimizes metabolism in several ways:

• Increases photosynthetic activity

• Promotes the development of flowers and fruits  

• Promotes plant growth and root biomass

Yeast and its derivatives thus represent a sustainable and economical opportunity for farmers. The flexibility of the derivatives’ action allows them to fulfill several promising functions to improve plant growth and resist abiotic stress.

The multifunctionality of yeast and its modes of action is also reflected in the diversity of strategies in which it can be used in conventional and organic agriculture.

To learn more about yeast’s capabilities and modes of action, Agrauxine has developed the concept of “Yeast Efficiency,” an innovative approach that leverages the many facets of yeast, applying it to biostimulation, biocontrol, and crop bionutrition.