Characterization and Biotechnological Potential of Intracellular Polyhydroxybutyrate by Stigeoclonium sp. B23 Using Cassava Peel as Carbon Source

Abstract

The possibility of utilizing lignocellulosic agro-industrial waste products such as cassava peel hydrolysate (CPH) as carbon sources for polyhydroxybutyrate (PHB) biosynthesis and characterization by Amazonian microalga Stigeoclonium sp. B23. was investigated. Cassava peel was hydrolyzed to reducing sugars to obtain increased glucose content with 2.56 ± 0.07 mmol/L. Prior to obtaining PHB, Stigeoclonium sp. B23 was grown in BG-11 for characterization and Z8 media for evaluation of PHB nanoparticles’ cytotoxicity in zebrafish embryos. As results, microalga produced the highest amount of dry weight of PHB with 12.16 ± 1.28 (%) in modified Z8 medium, and PHB nanoparticles exerted some toxicity on zebrafish embryos at concentrations of 6.25–100 µg/mL, increased mortality (<35%) and lethality indicators as lack of somite formation (<25%), non-detachment of tail, and lack of heartbeat (both <15%). Characterization of PHB by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC), and thermogravimetry (TGA) analysis revealed the polymer obtained from CPH cultivation to be morphologically, thermally, physically, and biologically acceptable and promising for its use as a biomaterial and confirmed the structure of the polymer as PHB. The findings revealed that microalgal PHB from Stigeoclonium sp. B23 was a promising and biologically feasible new option with high commercial value, potential for biomaterial applications, and also suggested the use of cassava peel as an alternative renewable resource of carbon for PHB biosynthesis and the non-use of agro-industrial waste and dumping concerns.

Recent Biotechnological Applications of Polyhydroxyalkanoates (PHA) in the Biomedical Sector—A Review

“…In order to address these challenges, several studies have put forth various alternatives aimed at mitigating manufacturing expenses [39]. These alternatives include utilizing industrial residues as substrates for raw materials [40], chemically modifying PHA, employing genetic engineering techniques to enhance cell growth, manipulating cell morphology, and enhancing characteristics such as altering synthesis pathways [41].…”

“…Impallomeni et al [62] and Mohandas et al [49] showed promising results for the development of carriers from MCL-PHA produced by Pseudomonas aeruginosa ATCC 27853 and PHA copolymer produced by Bacillus cereus MCCB 281 using glycerol as a carbon source, respectively. Mourão et al [40] showed the potential for adaptive PHB production for drug carriers by the Amazonian microalgae Stigeoclonium sp. B23 using hydrolyzed cassava bark as substrate.…”

Reviewing the Potential of Algae Species as a Green Alternative to Produce Nanoparticles: Findings from a Database Analysis

“…The majority of published articles (73%) are studies performed on a single species of algae, followed by experiments conducted on two species (12.16%). Interestingly, one study focused on the production of NPs (specifically silver and AgNPs) using seven different species of algae (Chlorophyta, Charophyta, and Cyanobacteria) [39]. In detail, 68 other species of algae belonging to 45 families are reported in the documents corpus.…”