Elsevier

Journal of Hazardous Materials

Volume 346, 15 March 2018, Pages 152-158
Journal of Hazardous Materials

Improvement of biosurfactant production by Wickerhamomyces anomalus CCMA 0358 and its potential application in bioremediation

https://doi.org/10.1016/j.jhazmat.2017.12.021Get rights and content

Highlights

  • Wickerhamomyces anomalus CCMA 0358 produced a promising biosurfactant.

  • Biosurfactant production was optimized through response surface methodology.

  • The surface tension was reduced in 24 h from 49 mN/m up to 29 mN/m in bioreactor.

  • The biosurfactant was stable at extreme conditions of salinity and temperature.

  • The biosurfactant facilitated the recovery of 20% of oil from contaminated sand.

Abstract

In this work, biosurfactant production by Wickerhamomyces anomalus CCMA 0358 was increased through the development of an optimized culture medium using response surface methodology. The optimized culture medium contained yeast extract (4.64 g/L), ammonium sulfate (4.22 g/L), glucose (1.39 g/L) and olive oil (10 g/L). Biosurfactant production using this medium was validated both in flasks and bioreactor, and the surface tension was reduced from 49.0 mN/m up to 31.4 mN/m and 29.3 mN/m, respectively. In both cases, the highest biosurfactant production was achieved after 24 h of growth. W. anomalus CCMA 0358 demonstrated to be a fast biosurfactant producer (24 h) as compared to other yeast strains previously reported (144–240 h). The produced biosurfactant remained stable at high temperature (121 °C), NaCl concentrations as high as 300 g/L, and pH values between 6 and 12. The crude biosurfactant allowed the recovery of 20% of crude oil from contaminated sand, being a promising candidate for application in bioremediation or in the petroleum industry.

Introduction

Surface-active compounds (surfactants) exhibit a wide variety of applications and are present in nearly every product and aspect of our daily life. They are included as active ingredients in the formulation of detergents, cleaning and personal care products and cosmetics, and are also used in bioremediation, as well as in agriculture, food, paper, textile and petroleum industries, among others [[1], [2], [3], [4], [5], [6], [7]]. Due to their structure, surfactants reduce the surface and interfacial tensions, which confers them properties such as detergency, emulsifying activity, foaming, and ability to solubilize and disperse hydrophobic compounds in aqueous phases [[1], [8], [9]]. The current worldwide production of surfactants is estimated to be 15 million tons per year [3]. Most of the traditional chemical surfactants commonly used are obtained from petrochemical resources, and exhibit high toxicity and low biodegradability [[9], [10]]. Given the increasing concern regarding the environmental hazard of synthetic surfactants, and in order to address the growing demand for eco-friendly alternatives, research focusing on the production of bio-based surfactants has increased in the past few years [11]. The market for these “green” alternatives to the traditional chemical surfactants is expected to increase up to USD 2800 million by 2023, with a worldwide production around 462 kilo tons per year [12].

Among the bio-based surfactants, biosurfactants, a heterogeneous group of surface-active compounds synthesized by different microorganisms, have emerged as promising alternatives to the synthetic surfactants. In the past 10 years, biosurfactants have received pronounced attention owing to their excellent interfacial activities, low toxicity, high biodegradability, and stability under extreme conditions of temperature, pH and salinity [[4], [8], [11], [13]]. As a result of these properties, biosurfactants could replace chemical surfactants in many industrial applications [[14], [15], [16], [17], [18]]. However, their large-scale industrial production and commercialization are still limited by the relatively low efficiency of their production and recovery processes, as well as the high price of the culture media used for their synthesis, which results in high production costs. Extensive efforts have been made to produce biosurfactants at a competitive cost through the use of agro-industrial wastes and by-products as substrates, and the development of effective recovery processes [[3], [9], [19], [20], [21], [22], [23], [24], [25], [26]]. Furthermore, the application of statistical experimental designs such as response surface methodology (RSM) has been successfully used to optimize the composition of the culture medium and the culture conditions to maximize biosurfactant production by different microorganisms [[23], [24], [25]].

In this work, the composition of the culture medium was optimized through RSM to increase the biosurfactant production by Wickerhamomyces anomalus CCMA 0358. The results obtained were validated in shaken flasks and bioreactor. The stability of the biosurfactant produced by this yeast at different environmental conditions, as well as its potential applicability in bioremediation was also studied.

Section snippets

Strain and culture conditions

The yeast strain W. anomalus CCMA 0358 (isolated from coffee processing by-products) was obtained from the Culture Collection of Agricultural Microbiology, CCMA (Department of Biology, Federal University of Lavras, Brazil). This isolate was identified as a promising biosurfactant producer in our previous work [27]. The yeast was grown in YEPG medium (10 g/L yeast extract; 20 g/L peptone; 20 g/L glucose; pH 6.5) at 28 °C and 200 rpm.

Biosurfactant production

The culture medium used for the production of biosurfactant by

Optimization of biosurfactant production using response surface methodology (RSM)

The yeast strain W. anomalus CCMA 0358 produced a new type of glycolipid biosurfactant using a culture medium containing yeast extract, ammonium sulfate, glucose and olive oil [27]. In this study, a RSM based on a CCD was used to optimize the concentration of the different medium components in order to maximize biosurfactant production by this yeast strain. Yeast extract (X1), ammonium sulfate (X2) and glucose (X3) were the independent factors selected to perform the optimization process. The

Conclusions

The biosurfactant produced by W. anomalus CCMA 0358 exhibited excellent surface active properties, as demonstrated by the low surface tension values achieved (from 49 mN/m up to 29 mN/m). Furthermore, it remained stable at high temperature (121 °C), high salinities (300 g/L NaCl) and pH values between 6 and 12. The crude biosurfactant allowed the recovery of 20% of crude oil from contaminated sand. The excellent surface tension reducing ability exhibited by this biosurfactant, together with its

Conflicts of interest

None.

Acknowledgements

The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for the financial support under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. The authors also thank the FCT for the financial support under the scope of the Project

References (33)

Cited by (51)

  • Biosurfactants production utilizing microbial resources

    2023, Industrial Applications of Biosurfactants and Microorganisms: Green Technology Avenues from Lab to Commercialization
  • Synthetic biology approaches for biosurfactants production by lactic acid bacteria

    2023, Lactic Acid Bacteria as Cell Factories: Synthetic Biology and Metabolic Engineering
  • Biological processes and the use of microorganisms in oily wastewater treatment

    2023, Advanced Technologies in Wastewater Treatment: Oily Wastewaters
  • Remediation of Waste Engine Oil Contaminated Soil using Rhamnolipid based Detergent Formulation

    2023, Materials Today: Proceedings
    Citation Excerpt :

    Surfactants are low molecular weight molecules with a hydrophilic head group and a hydrophobic tail, and their hydrophilic-lipophilic balance helps them to obtain their surface activity [11]. The characteristic of surfactants to interact simultaneously with both polar and non-polar substances allows them to reduce the interfacial tension and provide properties such as detergency, emulsification, foaming, mixing, and dispersion [12,13]. The raw materials obtained from crude oil sources generally show a high level of ecological toxicity and a low level of bio-degradability [14].

View all citing articles on Scopus
View full text