AbstractOptimal nutrition along with non-stress conditions has a significant impact on the quantity and quality of essential oil in medicinal plants. The objective of this research was to examine the possibility of improving the quantity and quality of essential oil in thyme through nutrition of the seedlings using Thiobacillus bio-fertilizer and treatment by Superabsorbent. For this purpose, seedlings of two thyme species (Thymus vulgaris and Thymus daenensis) were sown in pots and exposed to

more »

... ifferent levels of Thiobacillus and superabsorbent. Results of Gas Chromatography Mass Spectrometry (GC/MS) revealed that the main compounds detected for T. vulgaris were thymol (31.5%), p-cymene (23.4%), γ-terpinene (13.9%), linalool (38.3%) and carvacrol (2.7%) while the main compounds of T. daenensis were thymol (51.2%), o-cymene (12.9%), γ-terpinene (4.5%), linalool (1.7%) and borneol (3.1%). Furthermore, the application of Thiobacillus had a significant effect on α-pinene content (p = 0.05). Moreover, the interaction between superabsorbent and Thiobacillus significantly changed the percentage of thymol, borneol, and caryophyllene. In conclusion, the mean of essence components in T. vulgaris was more than T. daenensis with the exception of thymol and caryophyllene.