Cassava wastewater valorization for the production of biosurfactants: surfactin, rhamnolipids, and mannosileritritol lipids

Abstract

The global production of cassava was estimated at ca. 303 million tons. Due to this high production, the cassava processing industry (cassava flour and starch) generates approximately ca. 0.65 kg of solid residue and ca. 25.3 l of wastewater per kg of fresh processed cassava root. The composition of the liquid effluent varies according to its origin; for example, the effluent from cassava flour production, when compared to the wastewater from the starch processing, presents a higher organic load (ca. 12 times) and total cyanide (ca. 29 times). It is worthy to highlight the toxicity of cassava residues regarding cyanide presence, which could generate disorders with acute or chronic symptoms in humans and animals. In this sense, the development of simple and low-cost eco-friendly methods for the proper treatment or reuse of cassava wastewater is a challenging, but promising path. Cassava wastewater is rich in macro-nutrients (proteins, starch, sugars) and micro-nutrients (iron, magnesium), enabling its use as a low-cost culture medium for biotechnological processes, such as the production of biosurfactants. These compounds are amphipathic molecules synthesized by living cells and can be widely used in industries as pharmaceutical agents, for microbial-enhanced oil recovery, among others. Amongst these biosurfactants, surfactin, rhamnolipids, and mannosileritritol lipids show remarkable properties such as antimicrobial, biodegradability, demulsifying and emulsifying capacity. However, the high production cost restricts the massive biosurfactant applications. Therefore, this study aims to present the state of the art and challenges in the production of biosurfactants using cassava wastewater as an alternative culture medium.

Effect of Fermentation Time, pH, and Their Interaction on the Production of Volatile Fatty Acids from Cassava Wastewater

“…This hypothesis gains strength, particularly since this experiment was characterized by the production of high concentrations of total VFAs (approximately 3444 mgHAc/L) and the use of a substrate with a low carbohydrate concentration (546.34 mg/L), in contrast to the concentrations present in the substrate utilized in our previous experiments. As reported by de Oliveira Schmidt et al [42], the composition of CWW includes glucose, cyanide, carbohydrates, proteins, lipids, and minerals, which vary depending on environmental factors like soil, climate, and variety of cassava. According to Yu and Fang [43], acetate, propionate, butyrate, and i-butyrate can directly result from the fermentation of carbohydrates, proteins, and lipids.…”

Green Surfactants (Biosurfactants): A Petroleum-Free Substitute for Sustainability─Comparison, Applications, Market, and Future Prospects

“…These biosurfactants are characterized by mannose and erythritol linked to a fatty acid and are further classified based on the length of the hydrophobic fatty acid, degree of saturation, and degree of acetylation (mono-, di-, or triacetylated). They are primarily used in the formulation of beauty and personal care products. − …”

Toward Climate Neutrality: A Comprehensive Overview of Sustainable Operations Management, Optimization, and Wastewater Treatment Methods

“…However, they are often more expensive, complex, and influenced by environmental conditions. Despite these challenges, biosurfactants have a promising future as a sustainable alternative to chemical surfactants [61]. Biosurfactants are produced by microorganisms, with some yeasts presenting no risks of toxicity or pathogenicity, making them ideal for use in food formulations.…”