Vinasse: from a residue to a high added value biopolymer

Daiana V Trapé,Olivia V López,Marcelo A Villar

doi:10.1186/s40643-021-00476-1

Abstract

This work aimed to study the feasibility of using vinasse for polyhydroxybutyrate (PHB) production by Bacillus megaterium. To optimize the culture medium, a Box–Behnken design was employed considering carbon (C), nitrogen (N), and phosphorus (Ph) concentrations as independent variables and PHB productivity as the response variable. The productivity decreased when C or N were increased, probably due to the presence of phenolic compounds and the limitation of N for the production of PHB by Bacillus sp. bacteria. An additional experimental design to optimize the C/N ratio and growing conditions (fermentation time and temperature) was carried out. Fermentation time had a statistically significant effect on PHB productivity reaching 10.6 mg/L h. On the other hand, the variability in physicochemical properties of vinasse samples led to significant differences in PHB productivity. Lower productivity values were obtained when vinasse had higher values of DBO. Therefore, biopolymers production from vinasse is a feasible alternative to valorize this bioethanol by-product.Graphical

Highlights

Plastics obtained from non-renewable sources are one of the most used materials in the world, they are broadly integrated into today’s lifestyle and contribute to almost all product areas
Several materials have been investigated such as biobased poly(ethylene terephthalate), biobased poly(ethylene), biopoly(carbonate), bio-poly(amide), poly(hydroxyalcanoate)s (PHAs), and poly(lactic acid) (PLA), among others
total nitrogen (TN) content of V2017 was 4.3 times higher than the corresponding to V 2018. In the bibliography it was found TN values goes from 60 mg/L (Zanfonato et al 2018) to 587 mg/L (Popolizio 2017), demonstrating once again the variability of this by-product and the challenge when using it as carbon source to produce biopolymers via microbial fermentation

Summary

Introduction

Plastics obtained from non-renewable sources are one of the most used materials in the world, they are broadly integrated into today’s lifestyle and contribute to almost all product areas. Trapé et al Bioresources and Bioprocessing (2021) 8:130 periods of time (Andrady 2015). For this reason, in the last years, alternatives have been explored to replace petroleum derived plastics by materials obtained from natural sources. PHAs are polyesters of hydroxyacids naturally synthesized by bacteria as carbon reserve. These biopolymers are accumulated as cytoplasmic inclusions in certain bacteria during unbalanced growth conditions, usually characterized by an excess of the carbon source and the lack of at least one of the essential nutrients (Kovalcik et al 2019). Its applications include packaging materials, bags, containers, sutures, cardiovascular stents, targeted tissue repair/ regeneration devices, polymer-based depots for controlled drug release or implants, and disposable items like single-use cups and diapers (Koller 2018)

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