New trends in biotechnological processes to increase the environmental protection

A sustainable development can be achieved by deepening into more effective and eco-friendly products and technologies. From this point of view, the development of biotechnological processes to increase the environmental protection could be included in the best available techniques reference documents, the so-called BREFs, that cover, as far as practicable, the industrial activities to achieve an integrated pollution prevention and control. Members of the European Union are required to take these documents into account when determining the best available techniques, generally or in specific cases under the European Commission Directives. In order to include biotechnological processes into the BREFs, for example, for obtaining food and pharmaceutical additives, these products have to be cost competitive with those synthesized by chemical ways. Biotechnological processes are advantageous compared to the chemical ones since various metabolites can be obtained simultaneously in the same process, and these metabolites are more eco-friendly than their chemical counterparts. Additionally, this feature also matches the increasing demand of consumers for natural products, which has intensified the biotechnological production of natural additives. This special issue reports advances in the use of biotechnological processes for the treatment of contaminated soil or water as well as the revalorization of agroindustrial residues through the production of valuable metabolites such as biosurfactants or antioxidants, with applications in biomedicine, food industry, pharmaceutical industry, or environmental bioremediation

Optimization of clavulanic acid production by Streptomyces daufpe 3060 by response surface methodology

Clavulanic acid is a β-lactam antibiotic which has a potent β-lactamase inhibiting activity. In order to optimize its production by the new isolate Streptomyces DAUFPE 3060, the influence of two independent variables, temperature and soybean flour concentration, on clavulanic acid and biomass concentrations was investigated in 250 mL-Erlenmeyers according to a 2² central composite design. To this purpose, temperature and soybean flour (SF) concentration were varied in the ranges 26-34°C and 10-50 g/L, respectively, and the results evaluated utilizing the Response Surface Methodology. The experimental maximum production of clavulanic acid (629 mg/L) was obtained at 32°C and 40 g/L SF after 48 h, while the maximum biomass concentration (3.9 g/L) at 30°C and 50 g/L soybean flour, respectively. These values are satisfactorily close to those (640 mg/L and 3.75 g/L, respectively) predicted by the model, thereby demonstrating the validity of the mathematical approach adopted in this study.Brazilian Research Funding InstitutionsCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

Effect of Ultrasound-Ethanol Pretreatment on Drying Kinetics, Rehydration, Quality Parameters, and Functional Groups of BRS Vitória Grape Using Convective Drying

The aim of this study was to investigate the effects of ultrasound pretreatment to improve BRS Vitória grape convective drying. For this purpose, samples without any pretreatment (control) and samples pretreated with ultrasound and water (USW) or ethanol (USEtOH) were analyzed. The effects on drying and rehydration kinetics, quality parameters, total phenolic content, antioxidant capacity, and functional groups were studied through FTIR spectrometry. The results showed that the pretreatment with ultrasound and ethanol reduced the grape’s drying time by approximately 64%. The Weibull model was the best model to describe the kinetics of grape rehydration. USEtOH-pretreated samples exhibited the greatest rehydration ratio at both tested temperatures (25 and 50 °C), especially at the highest one. In terms of quality parameters, soluble solids content and color change were influenced by pretreatments, with USEtOH showing a substantial reduction in grape water activity and significant color change after drying. The content of total phenolics decreased after ultrasound pretreatments but increased during drying, with USEtOH showing better retention of these compounds. Antioxidant capacity was affected by drying, but ultrasound pretreatments mitigated losses. Functional group analysis revealed that pretreatments were able to preserve several groups identified by FTIR. These results highlighted the potential of emerging and non-thermal technologies as pretreatments for drying BRS Vitória grapes, which suggests their use in food industry applications

Insights into the effects of phenolic compounds on the growth of Chlorella vulgaris: The case of olive mill wastewater

Olive mill wastewaters (OMWW) are characterized by a large concentration of pollutants, among which polyphenols represent a large part. This study investigated the effect of different dilutions of a culture medium enriched with olive-derived phenolic compounds on Chlorella vulgaris growth and its ability to degrade each one of them. In particular, polyphenols were precisely identified and quantified by HPLC-DAD analysis, showing high removal efficiency by C. vulgaris cells. Notably, in a 20 % (v/v) medium simulating OMWW, polyphenol reduction reached 83 %, and COD reduction was as high as 98 %, without compromising microalgae growth or biomass productivity. To further assess the scalability of this bioremediation strategy, the study also examined the performance of C. vulgaris cultivated in an unsterilized OMWW medium at the optimal concentration of 20 % (v/v). The results confirmed that the proposed process could be successfully implemented under non-sterile conditions, a crucial factor for transitioning to pilot and large-scale industrial applications, with the system maintaining a polyphenol degradation efficiency of over 75 % within 14 days. Overall, the proposed green and potentially cost-effective process is a sustainable solution for the degradation of phenolic compounds from OMWW and the management of such high-polluting waste

Bacteriocin production by Lactobacillus plantarum ST16Pa in supplemented whey powder formulations

Whey, the main by-product of the dairy industry, is frequently disposed of in the environment without any treatment due to the high cost of this process. Alternatively, whey can be used as a medium to culture lactic acid bacteria and produce value-added products such as bacteriocins. In this work, we attempted to improve bacteriocin production by Lactobacillus plantarum ST16Pa in a whey powder formulation supplemented with additional sources of carbon, nitrogen, and vitamin B12 at different levels and varying the agitation intensity according to a Plackett-Burman experimental design. Only the addition of tryptone positively influenced the production of this bacteriocin. The results allowed us to identify a supplemented whey formulation, comprising 150 g/L of whey total solids plus 10 g/L of tryptone and soybean extract, whose fermentation by Lb. plantarum ST16Pa in shake flasks under agitation at 150 rpm led to a cell-free supernatant with an antimicrobial activity against Listeria innocua 6a CLIST 2865 (inhibition zone of 13.23 mm) close to that previously obtained in de Man, Rogosa and Sharpe medium by other authors. These results are significant considering that the same strain cultured in cheese whey did not previously display any antimicrobial activity

3G-biorefinery from olive oil pomace: Biocapture of CO2 from biogas and lipid production

In the primary sector, the roadmap to success lies in enhancing sustainability and advancing process development within the framework of the circular economy. However, sectors such as that of olive oil have difficulty achieving these goals, but the integration of 2G and 3G-biorefineries could allow to overcome these issues. In this work, CO2 of biogas generated from olive pomace was biocaptured by Chlorella vulgaris using a fed-batch strategy, in which biogas was bubbled directly into the culture medium to recover fatty acids with potential use as biofuel substrate. Results showed that the CO2 removal efficiency in fed-batch mode of operation was similar over 14 cycles, being approximately 83.3 ± 2.4 % as an average. Moreover, a methane percentage of 93.09 ± 0.87 % was achieved when the volume of bubbled biogas increased from 1.5 to 4.0 L. The effect of the fed-batch supply of biogas with 20 % CO2 was outstanding on both lipid and fatty acids methyl esters (FAMEs) contents. Compared to the air-fed photobioreactor, lipid and FAMEs productivities increased 5.1 and 4.4 times, while the percentage of FAMEs improved from 55.75 ± 0.93 % to 82.62 ± 1.24 %. Moreover, the lipid profile revealed a high content of saturated and monounsaturated fatty acidsXunta de Galicia | Ref. ED481B2018/073Xunta de Galicia | Ref. ED481D-2022-006Xunta de Galicia | Ref. ED431B 2021/2

Anthocyanin partition in aqueous two-phase systems based on isopropanol and sodium / ammonium sulfate

Partitioning of anthocyanins contained in the crude extract ofSyzygium cuminifruit was investigated in aqueous two-phase systems (ATPS) made up of isopropa-nol and Na2SO4/(NH4)2SO4.Na2SO4induced ATPS formation more effectivelythan (NH4)2SO4. The increase in temperature enhanced phase separation in the(NH4)2SO4ATPS, while the opposite occurred in the Na2SO4ATPS. The higherthe overall mixture concentration or temperature, the higher the values of tie-linelength and slope. In all systems and conditions, anthocyanins preferentially parti-tioned to the top phase. The partition coefficient and theoretical recovery yield inthe top phase varied in the ranges 1.14–1.77 and 53.31–63.87 % in the (NH4)2SO4ATPS, and in the ranges 1.94–21.50 and 65.90–95.55 % in the Na2SO4ATPS