Food for thought: Plant probiotics
Everyone in the Food & Health industry is talking about the great opportunities arising around the microbiome topic area and how probiotics can support the health of consumers, but have you heard about plant probiotics and what they are capable of doing? No? Carry on reading!
Probably most of us are wondering why tomatoes you buy in the supermarkets taste different to the ones you pick from your own tomato bush at home. Of course, fresh tomatoes still contain all the volatile flavour compounds which normally get lost during the long transport from countries like Spain or Morocco, but one of the main reason is that they were grown in soilless media, like rock wool.
Of course, growing tomatoes in soilless media is a really convenient production technique as you can apply water and nutrients directly to the plant so you have less drainage or can replace and sterilise the rock wool blocks more easily after the harvest, but this artificial media does not really contain beneficial microorganisms or even arbuscular mycorrhizal fungi to support the plant during the growing periods which supports the plants in many areas.
The result is that tomatoes, but also other vegetables and fruits from such soilless production systems, have fewer antioxidants, phenols and sometimes also grow slower compared to plants growing in normal soil containing different strains of bacteria and fungi, which results into different nutritional and taste profiles.
To counteract this effect you can modulate the growing media with probiotics. Adding Bacillus megaterium and Bacillus amyloliquefaciens, for example, to the growing media, tomatoes became higher in soluble sugar, in protein and vitamin C and also a higher yield per plant was measured.1
When it comes to the increase of the healthy Beta-Carotenoids it was found out that a mixture of Pseudomonas putida, Azotobacter chroococcum, Azospirillum lipoferum and a mixture of arbuscular mycorrhizal fungi (Glomus lipoferum, Glomus mosseae, and Glomus etunicatum) increased the lycopene antioxidant levels within the tomatoes significantly, which can also have beneficial effects on the color, taste and health effects of the tomato.²
These were just a few of probably thousands of such relationships which could help to improve the yields and quality of fruits and vegetables in soilless, but also soil-based production systems. A field of research which is definitely worth looking into, as yields can be increased without the need for additional fertiliser usage, which already damages the soils and groundwater reservoirs today.
In addition, looking into probiotics increasing the vitamin C and other antioxidants values can have a beneficial effect on the shelf life of fruits and vegetables and thereby in the reduction of food waste. Finally, we think that this research field is especially interesting for the new urban farming systems based on soilless media, as this can support them to improve the taste, the yields and also the resistance of the plants.
- Shen F, Zhu TB, Teng MJ, et al. (2016) Effects of interaction between vermicompost and probiotics on soil property, yield, and quality of tomato
- Ordookhani K, Khavazi K, Moezzi A, et al. (2010) Influence of PGPR and AMF on antioxidant activity, lycopene and potassium contents in tomato. Afr J Agri Res 5: 1108–1116