Special Issue: Biochemical Processes for Sustainability

Currently, we are faced with the need to develop solution that are sustainable in terms of the energy and material resources used, which implies environmental sustainability. Furthermore, environmental sustainability must go hand in hand with economic sustainability [1]. The solutions that we create under the principles of sustainability must be applied in a general way by society, and that will only be possible if environmental sustainability is accompanied by economic sustainability [2,3,4]. Biochemical processes have a strong relationship with sustainability [5]. A biochemical process is a chemical reaction optimized over millions of years. Thus, taking advantage of these natural processes, which have already been chemically and energetically optimized and perfected over millions of years, should be of great interest. Thus, one of our scientific objectives should be to find the optimal combination of biochemical and chemical processes that allows us to maximize the performance of natural resources (energy and materials) while having a minimal impact, or, if possible, a positive impact, on the environment in order to reverse past impacts and reach a situation of balance with it. We must take advantage of the resources that nature itself offers us, and we should combine them with science and ingenuity.

For all these reasons, this Special Issue includes scientific advances that explore and use biochemical technologies, promote the concept of the circular economy, ensure innovative treatments for the decontamination of water and air, etc. The result has been successful achieved, and we have compiled 15 cutting-edge studies that cover all the principles of sustainability.

Some of the research works included show the enormous potential of biotreatment with enzymes and microorganisms, such as the bio-innovative pretreatment of coarse wool fibers with enzyme complex scouring and percarbonate bleaching, which resulted in excellent fiber properties even for coarse wool [6]. Also, covalent methods of immobilization were successfully applied for the immobilization of an industrial glucosidase from Aspergillus fumigatus, which was used for cellobiose hydrolysis [7]. As mentioned above, we must use nature with maximum ingenuity, and in some of the studies presented in this Special Issue in which a mutant Saccharomyces cerevisiae was used, this was achieved by establishing a high-throughput Py-Fe³⁺ screening method. Mutant S. cerevisiae strains with high sugar tolerances were selected for study in this work [8]. So, the ethanol yield and sucrose utilization were increased respect normal strain. Another work reported the possibility of increasing the synthetic activity of a lipase through the use of a deep eutectic solvent based on menthol and a fatty acid, thus replacing the organic solvent that is normally used in this type of reaction [9]. The preparation of bioacrylic acid from lactic acid obtained by the fermentation of the sugar contained in carod pods was also proposed in [10].

Advanced materials were also studied, such as new low-cost cathodes based on polyoxometalates for microbial fuel cells that, thanks to the actions of microorganisms present in them, allowed for the purification of wastewater and the production of bioenergy [11]. Anther paper studied the molecular-level energy storage mechanisms of the MoS₂ electrode in imidazolium ionic liquid ([BMI⁺][PF₆⁻]) using molecular dynamics (MD) simulation, which provided useful guidance on improving the energy density of MoS₂ supercapacitors [12]. The formulations of adhesives using natural plants were also tested very satisfactorily [13]. These tests reduced the amount of formaldehyde while maintaining the mechanical properties and even increasing the viscosity. The use of carbon dioxide in carbon as a supercritical fluid antisolvent in complex systems was also analyzed [14]. It was possible to obtain a targeted mean particle size and a specific particle morphology. The effects of the amino esters of boric acid (AEBA) on the conditions of vapor–liquid equilibrium in binary mixtures of acetonitrile–water and ethanol–acetonitrile and a three-component mixture of ethanol–acetonitrile–water were also investigated [15]. It was shown that the use of AEBA removed all azeotropic points in the studied mixtures, which improved their separation.

New pollution treatments were also analyzed, such as the use of per- and polyfluoroalkyl substances (PFASs) through high-temperature pyrolysis (HTP) [16]. Other treatments used to reduce the contamination of mineral, vegetable and glycerol oils using cellulose nanocrystal (CNC)-based aerogels modified with 3-triethoxysilyl propyl isocyanate (TEPIC) were analyzed [17]. Stainless steel slag carbonation was studied and could have two interesting aspects: the resource utilization of metallurgical waste slag and the carbon reduction effect of CO₂ storage [18]. Furthermore, the removal of pesticides via tomato-washing water treatment was studied using a UVC/H₂O₂ advanced oxidative process [19]. Another research work explored new solvents for efficient acid gas decontamination by using an aqueous mixture of secondary alkanolamines [20].

As has been made clear in this Special Issue, nature-based solutions are a key pillar in the development of sustainable processes.