Microalgae as Contributors to Produce Biopolymers

Abstract

Biopolymers are very favorable materials produced by living organisms, with interesting properties such as biodegradability, renewability, and biocompatibility. Biopolymers have been recently considered to compete with fossil-based polymeric materials, which rase several environmental concerns. Biobased plastics are receiving growing interest for many applications including electronics, medical devices, food packaging, and energy. Biopolymers can be produced from biological sources such as plants, animals, agricultural wastes, and microbes. Studies suggest that microalgae and cyanobacteria are two of the promising sources of polyhydroxyalkanoates (PHAs), cellulose, carbohydrates (particularly starch), and proteins, as the major components of microalgae (and of certain cyanobacteria) for producing bioplastics. This review aims to summarize the potential of microalgal PHAs, polysaccharides, and proteins for bioplastic production. The findings of this review give insight into current knowledge and future direction in microalgal-based bioplastic production considering a circular economy approach. The current review is divided into three main topics, namely (i) the analysis of the main types and properties of bioplastic monomers, blends, and composites; (ii) the cultivation process to optimize the microalgae growth and accumulation of important biobased compounds to produce bioplastics; and (iii) a critical analysis of the future perspectives on the field.

Contribution of Fermentation Technology to Building Blocks for Renewable Plastics

“…In addition to bacterial strains, some microalgae and cyanobacteria also accumulate PHA granules in their cells. Despite the low PHA content, the advantage of using microalgae is that they can convert atmospheric CO 2 to PHA by autotrophic metabolism [104]. For example, Microcystis aeruginosa, Chlorella pyrenoidosa, Synechococcus subsalsus, and Spirulina sp.…”

Physicochemical and biological ageing processes of (micro)plastics in the environment: a multi-tiered study on polyethylene

“…Moreover, pristine PE samples after biofouling presented a wide -OH band too. This can be related to the abundant presence of -OH-containing compounds (e.g., cellulose, hemicellulose, and pectin) at the surface of microalgal biological material (Binda et al 2020;Madadi et al 2021).…”

Microalgal Biomass as Feedstock for Bacterial Production of PHA: Advances and Future Prospects

“…With 60% crystallinity, P3HB, is thought to be a suitable substitute to PP. It has a melting temperature of 175°C and transition temperature of 0–9°C ( Madadi et al, 2021 ). On the other hand, P(3HB-co-3HV) is more flexible with a melting temperature between 148 and 168°C and transition temperature of −5.5 to −2.2°C, making it more commercially profitable ( Samantaray and Mallick, 2012 ).…”

“…In general, microalgal biomass is rich in various proteins (10–47 wt% of CDW), starch components (10–20 wt% of CDW), and amylopectin (80–90 wt% of CDW), cellulose, and lipids (20–50 wt% of CDW) ( Wang et al, 2016 ; Sun et al, 2018a ; Madadi et al, 2021 ). Table 2 depicts the macromolecule composition of different microalgal strains.…”

“…Furthermore, temperature highly affects enzymes involved in starch production such as starch synthase and sucrose synthase. When temperature was increased from 5 to 20°C, carbohydrate content in C. vulgaris SO-26 plummeted from 70 to 50% ( Madadi et al, 2021 ). As such, depending on the surrounding climate, heating during winter and cooling during summers are advantageous to microalgae culturing.…”