Polyhydroxybutyrate (PHB) Synthesis by Spirulina sp. LEB 18 Using Biopolymer Extraction Waste

Abstract

The reuse of waste as well as the production of biodegradable compounds has for years been the object of studies and of global interest as a way to reduce the environmental impact generated by unsustainable exploratory processes. The conversion of linear processes into cyclical processes has environmental and economic advantages, reducing waste deposition and reducing costs. The objective of this work was to use biopolymer extraction waste in the cultivation of Spirulina sp. LEB 18, for the cyclic process of polyhydroxybutyrate (PHB) synthesis. Concentrations of 10, 15, 20, 25, and 30% (v/v) of biopolymer extraction waste were tested. For comparison, two assays were used without addition of waste, Zarrouk (SZ) and modified Zarrouk (ZM), with reduction of nitrogen. The assays were carried out in triplicate and evaluated for the production of microalgal biomass and PHB. The tests with addition of waste presented a biomass production statistically equal to ZM (0.79 g L) (p < 0.1). The production of PHB in the assay containing 25% of waste was higher when compared to the other cultivations, obtaining 10.6% (w/w) of biopolymer. From the results obtained, it is affirmed that the use of PHB extraction waste in the microalgal cultivation, aiming at the synthesis of biopolymers, can occur in a cyclic process, reducing process costs and the deposition of waste, thus favoring the preservation of the environment.

A Review on Established and Emerging Fermentation Schemes for Microbial Production of Polyhydroxyalkanoate (PHA) Biopolyesters

“…After cell harvest and polymer extraction, the remaining liquid phase containing cell debris was fed to follow-up cultures in the same PBR system; cultivations were carried out under artificial illumination (12 kW/m 2 ) and 12 h day/night cycles. As a major result, follow-up cultivations based on Spirulina waste resulted in similar biomass production as observed when using pure autotrophic cultivation medium, whereas PHB content in cells reached its highest value of almost 11% in a minimal medium supplemented with 25% Spirulina waste [111]. Similar recycling experiments were carried out before with the extremophile chemoheterotrophic haloarchaeon Hfx.…”

Bioremediation of agricultural runoff and biopolymers production from cyanobacteria cultured in demonstrative full-scale photobioreactors

“…reached about a 2.9%dcw of PHB using pretreated olive mill wastewater. daSilva et al (2018), reached a slightly higher value (10.6%dcw) using the biopolymer extraction wastes. On the other hand, carbohydrates concentrations are comparable to those obtained in previous studies under laboratory conditions.…”

Fabrication of biopolymer nanofibers from natural sources

“…LEB 18, which gives an output of 10.6% (w w À1 ). 100 Similarly, an attempt was made by Kuntzler et al 101 to produce PHB, with outstanding mechanical and thermal properties similar to those of synthetic polymers, using Spirulina sp. LEB 18.…”