Sophorolipids Production from Oil Cake by Solid-State Fermentation. Inventory for Economic and Environmental Assessment

Alejandra Rodríguez,Xavier Font,Teresa Gea

doi:10.3389/fceng.2021.632752

Alejandra Rodríguez, Xavier Font + Show 1 more

Open Access

https://doi.org/10.3389/fceng.2021.632752

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Abstract

Biosurfactants are being proposed as a substitute for surfactants in the framework of a circular economy strategy. Sophorolipids (SL) are a type of biosurfactant produced by yeast that can be produced through submerged or solid-state fermentation (SSF) processes. Even though sophorolipids are being produced at full scale, through submerged fermentations, environmental and technoeconomic information regarding its production through SSF is unavailable. An inventory of data necessary to perform preliminary economic and environmental assessments is presented in this study. Data was obtained from three SSF processes at 22-L reactor volume and from two SSF processes at 100-L reactor volume, using winterization oil cake and molasses as substrates, wheat straw as support material, and Starmerella bombicola as SL producing yeast. The effect of increasing the operation scale was assessed. Besides presenting parameters such as inoculum production, initial mass of substrates, and airflow requirements; process emissions (NH3, Volatile Organic Compounds, N2O, SH2 and CH4) and the biogas potential of the spent fermentation solids were also presented.

Highlights

Biosurfactants (BS) are becoming increasingly attractive in the market, industry, and scientific community
The SLs production process from oil cake was previously developed at lab scale (0.5 L bioreactors) using wheat straw as support, as reported by Jiménez-Peñalver et al (2016) and Rodríguez et al (2020), obtaining yields close to 0.2 g SL g−1 substrate and productivities around 2.7 g SL L−1 d−1 when fermenting at a constant temperature of 30°C
Production of SLs by Solid-state fermentation (SSF) with Starmerella bombicola, from oil cake and molasses using wheat straw as a support was assessed at a representative bench scale of 22 and 100 L

Summary

Introduction

Biosurfactants (BS) are becoming increasingly attractive in the market, industry, and scientific community. Does it avoid the spread of toxic compounds to humans and animals in the environment but it boosts the circular economy In this circular economy framework, the use of wastewaters, solid waste, and byproducts as substrates for fermentation processes is a key point to close material cycles. E.g., production of biosurfactants such as sophorolipids, the fermentation media should include hydrophilic and hydrophobic substrates, the latter having low water solubility. In these cases, SSF can take advantage of submerged fermentation processes, paving the way for the valorization of a broad type of solid substrates

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