Biovalorization of spent yeast for preparation of eucalyptus oil-based microcapsules

Abstract

Most essential oils (EOs) have insecticidal properties but their use is limited due to their sensitivity to heat, light, and oxidation. A biological way to overcome this is by their encapsulation in yeast thus stabilizing them and also serve as an insecticide. Spent yeast, an underutilized predominant by-product of the wine and beer industries, can be biovalorized for encapsulation process. The present study was conducted to prepare Eucalyptus oil-based spent yeast (Saccharomyces cerevisiae) microcapsules. The effect of pre-treating yeast cells with NaCl, and varying the mass ratio of yeast to oil on encapsulation efficiency and loading capacity was investigated. Subsequently, the stability of the microcapsules was studied at 4 °C and 28 °C for 60 days. Fluorescent microscopy, Fourier transform-infrared spectroscopy and Transmission electron microscopy were used to analyze the process. NaCl [5% (w/v)]was found to be optimal for plasmolysis, resulting in a loading capacity of 44.78 ± 0.56% and a mass ratio of 2:1:4 (plasmolysed yeast: oil: water) recorded the highest encapsulation efficiency of 82.39 ± 1.33%. The storage studies revealed that microcapsules retained the loaded oil and were stable. Analytical methods confirmed the enhancing effect of plasmolysis and successful encapsulation of eucalyptus oil in yeast cells. Further, as yeast is a preferred food for mosquito larvae, EO-encapsulated yeast can be a promising, eco-friendly mosquito larvicide. Hence, the present work demonstrates proof-of-concept at laboratory scale, the field validation of which is needed to translate it into scalable, real-world bioinsecticidal applications.

Keywords

Encapsulation / Essential oils (EOs) / Microcapsules / Saccharomyces cerevisiae / Spent yeast

References

[1] Bouyahya A, Et-Touys A, Bakri Y, Talbaui A, Fellah H, Abrini J, Dakka N. Chemical composition of Mentha pulegium and Rosmarinus officinalis essential oils and their antileishmanial, antibacterial and antioxidant activities. Microb Pathog, 2017, 111: 41-49

[2] Regnault-Roger C. Ramawat KG, Merillon JM. Essential oils in insect control. Natural products, 2013, Springer, Berlin, Germany40874107

[3] Isman MB. A renaissance for botanical insecticides?. Pest Manag Sci, 2015, 71(12): 1587-1590

[4] Pavela R, Benelli G. Essential oils as ecofriendly biopesticides? Challenges and constraints. Trends Plant Sci, 2016, 21(12): 1000-1007

[5] Kocher DK, Kumar S, Kapoor N. Ecofriendly management of mosquitos. In: Omkar, ed. Mosquitos: biology, pathology and management. Springer; 2024. pp. 331–66. https://doi.org/10.1007/978-981-97-4163-2_14

[6] Workman MJ, Gomes B, Weng JL, Ista LK, Jesus CP, David MR, Hurwitz I. Yeast-encapsulated essential oils: a new perspective as an environmentally friendly larvicide. Parasit Vectors, 2020, 13: 1-9

[7] Kelly PH, Yingling AV, Ahmed A, Hurwitz I, Ramalho-Ortigao M. Defining the mechanisms of action and mosquito larva midgut response to a yeast-encapsulated orange oil larvicide. Parasit Vectors, 2022, 15(1): 183

[8] Bishop JRP, Nelson G, Lamb J. Microencapsulation in yeast cells. J Microencapsul, 1998, 15(6761-773

[9] WHO. Guidelines for laboratory and field testing of mosquito larvicides. Geneva: World Health Organization; 2005.

[10] Salari R, Bazzaz BSF, Rajabi O, Khashyarmanesh Z. New aspects of Saccharomyces cerevisiae as a novel carrier for berberine. DARU J Pharm Sci, 2013, 21: 1-8

[11] Puligundla P, Mok C, Park S. Advances in the valorization of spent brewer's yeast. Innov Food Sci Emerg Technol, 2020, 62 102350

[12] Delphine N, Micaël BE, Christelle AI, Charlotte EA. Nutritional potential of spent brewer's yeast, a residual by-product of beer production in breweries for future applications. J Adv Biol Biotechnol, 2023, 26(9): 30-39

[13] Jaeger A, Arendt EK, Zannini E, Sahin AW. Brewer’s spent yeast (BSY), an underutilized brewing by-product. Fermentation, 2020, 6(4): 123

[14] Nelson G. Application of microencapsulation in textiles. Int J Pharm, 2002, 242(1–255-62

[15] Shi G, Rao L, Yu H, Xiang H, Pen G, Long S, Yang C. Yeast-cell-based microencapsulation of chlorogenic acid as a water-soluble antioxidant. J Food Eng, 2007, 80(4): 1060-1067

[16] Shi G, Rao L, Yu H, Xiang H, Yang H, Ji R. Stabilization and encapsulation of photosensitive resveratrol within yeast cell. Int J Pharm, 2008, 349(1–2): 83-93

[17] Shi G, Rao L, Xie Q, Li J, Li B, Xiong X. Characterization of yeast cells as a microencapsulation wall material by Fourier-transform infrared spectroscopy. Vib Spectrosc, 2010, 53(2): 289-295

[18] Gibbs F, Kermasha S, Alli I, Mulligan CN. Encapsulation in the food industry: a review. Int J Food Sci Nutr, 1999, 50(3): 213-224

[19] Kavetsou E, Koutsoukos S, Daferera D, Polissiou MG, Karagiannis D, Perdikis DC, Detsi A. Encapsulation of Mentha pulegium essential oil in yeast cell microcarriers: an approach to environmentally friendly pesticides. J Agric Food Chem, 2019, 67(17): 4746-4753

[20] Thomas AG. Preparation and standardization of essential oil (EO)-based Saccharomyces cerevisiae microcapsules. [M.Sc. Thesis]. Ludhiana, India: Punjab Agricultural University; 2024.

[21] Dimopoulos G, Katsimichas A, Tsimogiannis D, Oreopoulou V, Taoukis P. Cell permeabilization processes for improved encapsulation of oregano essential oil in yeast cells. J Food Eng, 2021, 294 110408

[22] Kavosi M, Mohammadi A, Shojaee-Aliabadi S, Khaksar R, Hosseini SM. Characterization and oxidative stability of purslane seed oil microencapsulated in yeast cells biocapsules. J Sci Food Agric, 2018, 98(7): 2490-2497

[23] Czerniak A, Kubiak P, Białas W, Jankowski T. Improvement of oxidative stability of menhaden fish oil by microencapsulation within biocapsules formed of yeast cells. J Food Eng, 2015, 167: 2-11

[24] Shi G, Liu Y, He Z, Zhou J. Chemical treatment and chitosan coating of yeast cells to improve the encapsulation and controlled release of bovine serum albumin. Artif Cells Nanomed Biotechnol, 2017, 45(6): 1207-1215

[25] Paramera EI, Karathanos VT, Konteles SJ. Yeast cells and yeast-based materials for microencapsulation. In: Microencapsulation in the food industry. Academic Press; 2014. pp. 343–65

[26] Liu S, Tuang M, Huang K. Encapsulation of Manuka essential oil in yeast microcarriers for enhanced thermostability and antimicrobial activity. Food Bioprocess Technol, 2021, 14: 2195-2206

[27] Ciamponi F, Duckham C, Tirelli N. Yeast cells as microcapsules. Analytical tools and process variables in the encapsulation of hydrophobes in S. cerevisiae. Appl Microbiol Biotechnol, 2012, 95: 1445-1456

[28] Paramera EI, Konteles SJ, Karathanos VT. Microencapsulation of curcumin in cells of Saccharomyces cerevisiae. Food Chem, 2011, 125(3): 892-902

[29] Burattini E, Cavagna M, Dell’Anna R, Campeggi FM, Monti F, Rossi F, Torriani S. A FTIR microspectroscopy study of autolysis in cells of the wine yeast Saccharomyces cerevisiae. Vib Spectrosc, 2008, 47(2): 139-147

[30] Sharma AD, Farmaha M, Kaur I, Singh N. Phytochemical analysis using GC-FID, FPLC fingerprinting, antioxidant, antimicrobial, anti-inflammatory activities analysis of traditionally used Eucalyptus globulus essential oil. Drug Anal Res, 2021, 5(1): 26-38

[31] Günal-Köroğlu D, Bilgin AB, Karabulut G, Saricaoglu B, Capanoglu E. Encapsulation of hydrophobic compounds in yeast cells: methods, characterization, and applications. Explor Foods Foodomics, 2024, 2: 252-274

Funding

Science and Engineering Research Board(DST-SERB SPG/2021/002695)

RIGHTS & PERMISSIONS

Jiangnan University