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.

Biosurfactants are amphipathic molecules with growing worldwide interest because of their low toxicity, high biodegradability and good ecological acceptability. They are produced by microorganisms and between them, filamentous fungi belonging Mucorales order have been reported as promising producers. However, most of these studies still use traditional submerged fermentation, a methodology with technical and economic problems. In this context, this work aimed the production of biosurfactant by Mucor hiemalis UCP 1309 using solid-state fermentation (SSF) as a low-cost alternative technology. Experiments were carried out using seven agro-industrial byproducts and wastes as substrates, supplemented with salt solution containing 5% waste soybean oil (WSO). Medium with the best result in the production of biosurfactant was used in a second fermentation, where a 22 full-factorial design (FFD) was performed to investigate the influence of inoculum size and concentration of WSO on surface tension. The results showed higher reduction of surface tension (to 28.1 mN/m) in fermentation using wheat bran. Also, the statistical analysis demonstrated significant effect of concentration of WSO on surface tension. Produced biosurfactant demonstrated excellent emulsifying properties with WSO, motor oil and burned motor oil, and the emulsions remained stable after 90 days of incubation. Therefore, this work demonstrated SSF as a suitable strategy for getting inexpensive and efficient biosurfactant and expediting its large-scale production. Moreover, we report, for the first time in the international literature, the production of biosurfactant using SSF by a Mucoralean fungus.

Prodigiosin is a microbial red pigment, mainly produced by the bacterium Serratia marcescens, considered as a promising antimicrobial, immunosuppressive and antiproliferative compound. However, its industrial commercialization is still limited because of the high cost of production mainly due to the use of expensive substrates. Hence, this work aimed to the sustainable production of prodigiosin by S. marcescens UCP 1549, using corn bran as alternative and low-cost substrate, and its application in soap coloring. According to the results, both bacterial growth and red pigment production occurred, achieving 7.24 g/L and 1.68 g/L of biomass and pigment yield, respectively. Positive result in the presumptive test indicated red pigment as prodigiosin, which was confirmed by UV-Visible spectrophotometry (maximum absorbance peak at 535 nm), TLC (Rf 0.9) and the functional groups identified by FTIR spectroscopy. Prodigiosin showed color stability at different pH values and NaCl concentration. The application of pigment in soap coloring was effective, suggesting its promising potential in the cosmetics industry as natural colorant. The results showed the biotechnological potential of S. marcescens UCP 1549 in the biotransformation of corn bran into prodigiosin, allowing a more economically and competitively industrial bioprocess.

This study focused on the low-cost production of biosurfactant by Bacillus subtilis UCP 0999, using cassava wastewater (CWW) and waste frying oil (WFO) as renewable substrates. A 22 full-factorial design (FFD) was employed to investigate the effects of concentrations of agro-industrial wastes in surface tension (ST) and emulsification index (EI24). According to the results, the minimum value of ST (33.2 mN/m) and the maximum value of EI24 (95%) was obtained at central point of the FFD, using 5% CWW and 2% WFO. Statistical analyses demonstrated the significative influence of both substrates in ST and EI24. The biosurfactant showed 2.67 g/L yield and anionic and lipopeptide nature by Zeta potential and Fourier transform infrared (FT-IR) spectroscopy, respectively. In addition, promising applications of biosurfactant as biodispersant and viscosity reducing agent were demonstrated, suggesting its potential use in petroleum industry or bioremediation of hydrophobic pollutants.

The present work evaluated the biotechnological potential of the fungus Penicillium sclerotiorum UCP 1040, isolated from the soil of the State of Pernambuco, for the production of biosurfactant using agro-industrial waste as alternative sources of carbon and nitrogen. Fermentations were carried out for 144 h, 28ºC and 150 rpm, in media consisting of different concentrations of post-frying oil (PFO) and corn steep liquor (CSL), according to a 2² factorial design. The effects of substrates on surfactant production were evaluated through statistical analysis, using surface tension as response variable. The emulsifying and dispersing properties of biosurfactant were investigated by emulsification index (EI₂₄) and dispersion test, respectively. The results obtained showed that P. sclerotiorum was able to produce a surfactant compound in the presence of renewable substrates, with the greatest reduction in surface tension (from 72.0 to 42.77 mN/m) in condition 2 of the design (medium consisting of 3% PFO and 5% CSL). Although the biosurfactant produced in this condition did not show good emulsifying properties, it exhibited excellent dispersing properties, with oil dispersion area (ODA) of 44.18 cm². The Pareto diagram verified the significant influence of the interaction of wastes in the production of biosurfactant, constituting alternative and low-cost substrates, which make the bioprocess economical and, therefore, attractive for different industries.

In this work it was investigated the potential of Mucorales fungi isolated from the Caatinga of Pernambuco state for production of biosurfactants using renewable substrates. The strains (Mucor circinelloides UCP 0005, M. circinelloides UCP 0006 and Rhizopus arrhizus UCP 1609) were cultivated in alternative culture media consisting of instant noodle waste (INW), corn steep liquor (CSL) and post-frying soybean oil (PFSO), according to conditions established by a 23 full-factorial design (FFD). The production of biosurfactants was evaluated by determining surface tension and emulsification index (EI24) and statistical analysis was performed using Pareto diagram. The presence of the main sources of carbon and nitrogen in production medium was confirmed by FTIR spectroscopy. According to the results, the three fungi evaluated were able of produce biosurfactant in media containing renewable sources. However, the strain that showed the greatest reduction in surface tension (72 to 27 mN/m) was M. circinelloides UCP 0006 in condition 3 of the FFD (1% INW and 4% CSL, in absence of PFSO). The infrared analysis of the INW showed the presence of carbohydrates, fatty acids and proteins, proving that this is a suitable substrate for the cultivation of fungi. The biosurfactants produced by M. circinelloides UCP 0005 and M. circinelloides UCP 0006 were able to form water-in-oil emulsions and the biosurfactant from R. arrhizus UCP 1609 formed oil-in-water emulsions. The present study demonstrated that the three Mucorales fungi tested were able to produce biosurfactants from renewable sources, with emphasis on M. circinelloides UCP 0006.