Chitosan is a cationic polymer obtained by deacetylation of chitin, found abundantly in crustacean, insect, arthropod exoskeletons, and molluscs. The process of obtaining chitin by the chemical extraction method comprises the steps of deproteinization, demineralization, and discoloration. To obtain chitosan, the deacetylation of chitin is necessary. These polymers can also be extracted through the biological extraction method involving the use of microorganisms. Chitosan has biodegradable and biocompatible properties, being applied in the pharmaceutical, cosmetic, food, biomedical, chemical, and textile industries. Chitosan and its derivatives may be used in the form of gels, beads, membranes, films, and sponges, depending on their application. Polymer blending can also be performed to improve the mechanical properties of the bioproduct. This review aims to provide the latest information on existing methods for chitin and chitosan recovery from marine waste as well as their applications.

In this work, we investigated the potential of Bacillus subtilis UCP 0146 in the bioconversion of a medium containing 100% cassava flour wastewater to obtain a bioemulsifier. The evaluation of the production was carried out by the emulsification index (IE24) and the surface tension (ST). The ionic charge, stability (temperature, salinity, and pH measured by IE24 and viscosity), and ability to remove and disperse oil and textile dye were investigated. B. subtilis produced an anionic bioemulsifier in the medium containing 100% cassava wastewater under Condition 4 of the factorial design (inoculum 9% at a temperature of 35 °C and shaken at 100 rpm), and showed a surface tension of 39 mN/m, an IE24 of 95.2%, and a yield of 2.69 g·L−1. The bioemulsifier showed stability at different pH (2–8), temperatures (0–120 °C), and NaCl concentrations, a dispersion oil displacement area (ODA) test of 55.83 cm2, and a reduction of the viscosity of the burned engine oil (90.5 Cp). The bioemulsifier was able to remove petroleum (94.4%) and methylene blue azo dye (62.2%). The bioemulsifier and its synthesis from bacteria also emphasizes the role of surfactants in oil remediation.

The world market for biosurfactants has grown gradually. However, the lack of competitiveness with chemical surfactants due to high cost of production remains a concern. Considering the need to reduce the costs of production, the aim of this work was to study the production and structural characterization of a biosurfactant produced by a strain of yeast Candida glabrata UCP 1556. The lowcost medium containing agro-industrial wastes whey 40% (v/v) and 20% (v/v) corn steep liquor were used as substrates in submerged fermentation. Biosurfactant production was detected by surface tension, oil displacement test and Critical Micelle Concentration (CMC). The structural characterization was performed by Fourier transform infrared (FT-IR), gas chromatography-mass spectrometry (GC-MS) and ionic profile. The stability of emulsions and potential in reducing the viscosity also were investigated. The results showed that the biosurfactant reduced the surface tension to 28.8 mN/m with CMC of 2% and showed anionic profile. Additionally, the biosurfactant formed stable emulsions at temperature (0 to 120°C), pH (2 to 12) and NaCl (2 to 12%), reduced the viscosity of soybean oil (

The successful production of a biosurfactant is dependent on the development of processes using low cost raw materials. In the present work, an economically attractive medium composed of corn steep liquor and waste cooking oil was formulated to maximize the production of bioemulsifier by Mucor circinelloides UCP0001. A central rotational composite design was applied to statistical validation of the production. The emulsifying properties, stability under extreme conditions, its toxicity character, and the characterization of the bioemulsifier were determined. The best condition for biomolecule synthesis occurred in the assay 2 containing 4% of corn steep liquor and 3% waste soybean oil and exhibited 100% emulsification index for canola oil and petroleum, as well as excellent emulsifying activity for canola oil and burned engine oil. The nutritional factors studied showed statistical relevance, since all linear, quadratic effects and their interactions were significant. The bioemulsifier showed 2.69 g/L yield and the chemical character of the molecule structure was identified by FT-IR (Fourier Transform Infrared) spectroscopy. The bioemulsifier showed no toxicity to Artemia salina and Chlorella vulgaris. Stable emulsions were obtained under extreme conditions of temperature, pH, and salinity. These findings contribute to understanding of the relationship between production, physical properties, chemical composition, and stability of bioemulsifier for their potential applications in biotechnology, such as bioremediation of hydrocarbon-contaminated soil and water.

In this study, chitin and chitosan were extracted from Litopenaeus vannamei waste using chemical and microwave methods. Shrimp waste was cleaned, dried and ground sieved to 16, 32 and 60 mesh, and the samples were depigmented, demineralized, and deproteinized. Then, the chitin was submitted to a deacetylation process by 45% NaOH solution under microwave irradiation at 600w, for intermittent 15 min or using 5 pulses of 5 minutes. The study showed that the effectiveness of the particle size of 32 mesh and 6 pulses of 5 min to deacetylation with 92% of degree and chitosan yield (52.2%). The polymer chitosan showed higher antimicrobial activity against to Staphylococcus aureus, Escherichia coli, Salmonella enterica and the yeast Candida sp., respectively. The results indicated the feasibility of the microwave radiation as an attractive method to recover chitin and chitosan from shrimp wastes.

This study reports the complete chloroplast sequences of three Spondias species. The genome sequences were obtained for Spondias tuberosa, Spondias bahienses, and Spondias mombin using the Illumina sequencing technology by a combination of de novo methods and a reference-guided assembly using Sapindus mukorossi as reference. The genomes of S. tuberosa, S. bahiensis, and S. mombin had 162,036, 162,218, and 162,302 bp, respectively. The coding regions exhibited 130 genes, including 34–35 tRNAs and 4 rRNAs. The results revealed synteny among the genomes, with high conservation in the gene order and content and CG content. The inverted repeat regions (IRA and IRB) and the large and small single copies were very similar among the three genomes. The phylogenomic analysis reported similar topologies as that of previous studies, which used partial chloroplast, wherein S. mombin was the first diverging lineage, while S. tuberosa and S. bahiensis were derived, indicating that the phylogenetic analysis using partial or complete genome produces similar results. In summary, (1) we presented the first complete chloroplast genome for the genus Spondias, (2) phylogenies analyzed using the complete chloroplast genomes revealed a robust phylogenetic topology for Spondias, and (3) gene order, content, and orientation in Spondias are highly conserved.

A novel bacterium pigmented isolate from Caatinga soil was characterized by biochemical and molecular assays, as well as, by rep-polymerase chain reaction (PCR) and 16S rDNA sequencing, and was identified as Serratia marcescens based on 99% of similarity. The identity of the sequences were compared by pairs of critical species of S. marcescens found in National Center for Biotechnology Information (NCBI) with a 96% homology of the isolated species to species database. The wild strain was able to produce biosurfactant (BS) using cassava (Manihot esculenta Crantz) wastewater, with addition of lactose, and corn oil, according to full factorial design 2 3 , at 28°C, and static condition. The net liquid metabolic reduced the surface tension of the water from 70 to 30.60 mN/m during the stationary phase (assay eight constituted by 6.0% cassava wastewater, 1.0% lactose and 7.5% corn oil), and produced emulsifier agent (4.012 UEA) at the same condition. This study identified the pigmented bacterium as new strain of S. marcescens, and showed it has potential to promote both emulsions formation and surface tension reduction in cassava wastewater (6.0%), lactose (1.0%) and corn oil (7.5%) proved as an alternative economical medium for commercial biosurfactant processes.

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