Enhanced production of 2-phenylethanol by salicylic acid and cyclodextrins in cell suspension cultures of the unexplored filamentous fungus Monochaetinula geoffroeana

Abstract

2-Phenylethanol (PEA) is a higher aromatic alcohol with a rose-like odor, which is used in several industries. Although PEA can be synthesized, consumers are increasingly concerned about the toxicity of chemically synthesized products, and prefer natural aroma compound. PEA occurs naturally in the environment but concentrations are too low to justify extraction. The present study offers a novel biological source of PEA: the filamentous fungi Monochaetinula geoffroeana. We report the highest recorded yield of PEA of fungal origin to date: 6.52 g L−1. The volatility and low water solubility of PEA can affect its use in many industries, for which reason complexation studies of PEA and cyclodextrins were carried out using the phase solubility technique. PEA formed 1:1 stoichiometric inclusion complexes with natural and modified CDs, the highest encapsulation constant being obtained with MβCD (K1:1 = 299.88 L mol−1). The complexation process significantly increased the water solubility of PEA. A computational study showed a high degree of correlation between computed scores and experimental values. Furthermore, this study reports the role of salicylic acid as an effective elicitor for improved PEA production by the studied fungi. Supplementation with 10 μmol L−1 salicylic acid increased PEA production from 6.52 to 10.54 g L−1. The best treatment to enhance PEA production by M. geoffroeana under laboratory conditions was to use salicylic acid 10 μmol L−1. Due to the commercial importance of PEA, further investigation is needed to improve PEA production by M. geoffroeana and to optimize culture conditions in order to standardize yields.