New research by Ayola, a Turkish supplier of hybrid vertical farming systems, grew lettuce in vitro conditions and vegetative experiments in soil. The experiment was held from April 4-27 in 2023. The seeds used for the lettuce variety were Lactuva sativa L.
Two variants were applied: Control, which is in water, non-inoculated, and non-colonized. And, Colonized, which is inoculated with the 'Methylotroph.'
For in vitro experiments, lettuce seeds were sterilized with a 5% sodium hypochlorite solution (containing chlorine) for 2-3 minutes, followed by three rinses with sterile water. Sterile lettuce seeds were aseptically transferred onto 0.75% agar containing a 10 μl suspension of "Methylotroph" cell culture in the exponential growth phase, with a density of 105-107 CFU/ml. The plants were cultured at 21-23°C with a 16-hour light period for two weeks.
Vegetative experiments were conducted in soil using a commercial composition for seedling and houseplant cultivation. In 2-liter transparent plastic containers, 500 ml of soil was added and moistened with 100 ml of boiled distilled water. The seeds were placed on the soil surface (5x4, with several seeds per spot, totaling 50-60 seeds per container), with a repetition of two containers. In total, approximately 100-120 seeds were used for each variant.
Results of the vitro experiment
The results were recorded on the 7th and 14th day of seedling growth. On the 7th day of growth (Fig. 1), the cotyledon leaves of the seedlings inoculated with the "Methylotroph" strain were larger and greener compared to the control (as seen in the photo with the "cell" background).
Additionally (as shown in the photo on the blue background), it was noted that the roots were larger and more branched compared to the roots of the control seedlings (on the right).
Fig. 1: Lettuce seedlings on the 7th day of growth under in vitro conditions
On the 14th day of growth (Fig. 2), the seedlings also showed noticeable differences. The control seedlings were more yellow (on the right), indicating a lack of nutrients and imminent plant death (with greenish-yellow leaves and yellowing roots). The colonized seedlings remained green, with white roots that were well-branched.
Fig. 2: Lettuce seedlings on the 14th day of growth under in vitro conditions
Results of the vegetative experiments
The plant growth was monitored for 17 days. It was observed that the colonized plants exhibited increased growth and larger leaf size compared to the control plants (Fig. 3, 4).
Fig. 3: Lettuce seedlings on the 17th day of growth, side view
Fig. 4: Lettuce seedlings on the 17th day of growth, top view
An equal number of random plants (23-25) were selected from each variant's container, removed from the soil, and arranged in rows of 10-15 plants (Fig. 5).
Fig. 5: Lettuce seedlings on the 17th day of growth
It was noted that the colonized plants were more developed, with multiple well-developed leaves, and they were taller than the control plants.
Number of seedlings, count
Total weight, gram
Weight per seedling, mg
Table: Weight of dried seedlings (green mass) for the control and colonized strains by "Methylotroph."
The seedlings, placed on paper, were separated from the roots and dried at a temperature of 90°C until a constant weight was reached within a day.