Valorization Of Industrial Wastes Research Articles

Reuse of Residual Brewer’s Yeast: Valorization of Industrial Waste as a Source of Nutrients for Dairy Cattle

Reuse of Residual Brewer’s Yeast: Valorization of Industrial Waste as a Source of Nutrients for Dairy Cattle

Investigation of pectin deficiency in modulating the bioflavonoid profile of orange processing waste: A sustainable valorization of industrial waste

Orange processing waste (OPW) generated by the processing of oranges, as well as other citrus fruits, is a major source of pectin in the market nowadays. The residues generated during the pectin extraction process may contain many phytochemicals, including flavonoids. We use state-of-the-art techniques such as liquid chromatography high-resolution mass spectrometry (LC-HRMS/MS) and feature-based molecular network (FBMN) to annotate the flavonoids in OPWs. In particular, four flavonoids, hesperidin, naringin, diosmin, and hesperetin were quantified in the samples by LC-TDQ-MS. In total, 32 flavonoids from different classes were annotated, of which 16 were polymethoxylated flavonoids, 13 were flavonoid glycosides and 3 were flavanone aglycones. The results showed that flavonoid glycosides remain in high concentrations in OPWs from pectin factories even after pectin extraction by harsh conditions. The results show an exciting opportunity to harness the untapped potential of pectin factory waste as a renewable source for the extraction of glycoside flavonoids.

Effect of Strapping Straps Waste Fibers on Fresh and Hardened Properties of Concrete

Abstract Faced with the increasingly growing need for construction material resources and the strict requirements and conditions for preserving the environment, it has become necessary and relevant to study all possibilities and opportunities for the recycling and valorization of industrial waste and by-products in the construction field. Strapping straps is a product used to bundle and transport goods and construction materials. After its use, it is considered as waste. The objective of this experimental work is to study the possibility of reusing the strapping strap waste as fibers in the production of fiber-reinforced concrete. For this purpose, three families of concrete were composed using strapping strap fibers, steel fibers, and polypropylene fibers, which were introduced into a concrete composition by volumetric substitution (0.4%, 0.8% and 1.2%) of aggregates. The fresh properties were evaluated through slump, density and air content tests. Hardened properties were investigated using the compressive and flexural strengths, pulse velocity, dynamic elastic modulus, and water absorption tests. The results obtained showed that strapping strap waste fibers significantly improve the mechanical properties of fiber-reinforced concrete and have a behavior similar to that of steel fibers. The optimum rates of strapping strap fibers were 0.4% and 1.2% for compressive and flexural strengths respectively. Compared to polypropylene fibers, the strapping strap fibers were found to be more efficient and led to a gradual increase in flexural strength with an increase in the strapping strap fibers. The results obtained also showed that the increase in strapping strap fiber content gradually increased the water absorption of fiber-reinforced concrete.

Extraction of 4-hydroxy benzoic acid from potato processing industrial waste

Abstract Due to the substantial volume of waste produced and the potential for high-value bioactive compounds to be extracted from potato peel, the valorization of industrial waste of potato processing industry is the subject of this research. The study presents an innovative technique for efficient extraction of 4-hydroxybenzoic acid (P-HBA), a valuable bioactive molecule, from potato peel extract by utilizing molecularly imprinted chitosan beads (MICB). The MICB was synthesized using environmentally benign cross-linkers such as Tetraethyl orthosilicate (TEOS), Sodium triphosphate (STPP), while P-HBA was is used as a template. The MICB was investigated using FTIR, SEM, and EDAX. Adsorption studies were conducted to optimize parameters like adsorbent dose, solution concentration, time and pH. A recovery rate of 95.07 % is recorded from a synthetic P-HBA solution when measured by HPLC while from the actual potato processing industrial effluent the same is 40 %. The adsorption capacity of MICB is 67.5 mg g−1 and specific binding capacity is 20.62 mg g−1 which remained unchanged for six consecutive cycle reuse. This is the first study to report uptake of a bioactive molecule from actual potato processing industry waste.

Valorization of glass waste as partial substitution of sand in concrete – Investigation of the physical and mechanical properties for a sustainable construction

Over the past few years, the valorization of industrial waste and by-products has become an essential issue due to the increasingly stringent regulations regarding the environmental protection and sustainable development. For the purpose of reducing our dependence on virgin raw materials, it was deemed interesting to consider the recycling and valorization of glass, which has high silica content, to develop new construction materials. Its use as a substitute raw material in the field of construction materials has attracted research attention, particularly the concrete industry adopts a number of methods to achieve this goal. In this context, a purely experimental study was conducted to investigate the physical and mechanical properties of fresh and hardened concrete at different curing times (3, 7 and 28 days) using different dosages of glass sand as a partial substitute for natural sand at 10%, 20%, and 30% and to determine the optimal composition of glass powder as a partial replacement for sand against the compressive strength of concrete. while maintaining a constant water-to-cement (W/C) ratio. An overall quantity of 9.5 kg of crushed waste glass was used with 264 kg of concrete mixes. The workability, density, slump, content air tests and strength properties were analyzed in terms of waste glass content in terms of waste glass content. This substitution results in concrete with favorable workability. Despite the absence of air-entraining agent, the concrete mixtures have air content between 2.3% and 1.9% and the density, is still comparable to the control mixes. The compressive strength of specimens with 20% waste glass content and the flexural strength of specimens with 10% waste glass content represented respectively 96% and 86% than of the control specimen at 28 days. The results proved a pozzolanic strength activity given by waste glass after 28 days for 10% and 20% of replacement of natural sand (0/1 mm). The results obtained indicate that glass can serve as a quality substitute for sand in concrete. These original achievements pave the way for more sustainable and environmentally friendly concrete mixes while addressing the inherent challenges of using glass waste in construction and infrastructure works

Amino acid promoted single-step carbon dioxide capture and mineralization integrated with polymer-mediated crystallization of carbonates

Integrated CO2 capture and mineralization is a promising technology for cutting CO2 emissions and associated environmental impacts. Two major challenges in CO2 mineralization in aqueous media are (1) the lack of green and energy-efficient processes and (2) limited applications of the produced carbonates. Here, we present a very efficient, environmentally friendly, and convenient integrated CO2 capture and mineralization method to produce functional calcium carbonate (CaCO3) particles. We use a gas diffuser reaction setup to bubble CO2 in liquid media containing reagents such as amino acid as CO2 absorption promotor, water-soluble polymers as crystal growth modifiers, and Ca2+ ions. Different concentrations of amino acid L-arginine with a fixed CO2 bubbling rate were investigated for Ca2+ conversion. At the optimized conditions, more than 90% Ca2+ was converted to CaCO3 within 5 min of CO2 bubbling at a nominal rate. Additionally, functional carbonates that could be used as dye, heavy metals adsorbents, and functional composite fillers are produced using crystal growth modifiers. The method is simple, efficient, eco-friendly, and could be used for CO2/Ca2+-rich industrial waste valorization.

Characterization of chitinases from the GH18 gene family in the myxomycete Physarum polycephalum

BackgroundPhysarum polycephalum is an unusual macroscopic myxomycete expressing a large range of glycosyl hydrolases. Among them, enzymes from the GH18 family can hydrolyze chitin, an important structural component of the cell walls in fungi and in the exoskeleton of insects and crustaceans. MethodsLow stringency sequence signature search in transcriptomes was used to identify GH18 sequences related to chitinases. Identified sequences were expressed in E. coli and corresponding structures modelled. Synthetic substrates and in some cases colloidal chitin were used to characterize activities. ResultsCatalytically functional hits were sorted and their predicted structures compared. All share the TIM barrel structure of the GH18 chitinase catalytic domain, optionally fused to binding motifs, such as CBM50, CBM18, and CBM14, involved in sugar recognition. Assessment of the enzymatic activities following deletion of the C-terminal CBM14 domain of the most active clone evidenced a significant contribution of this extension to the chitinase activity. A classification based on module organization, functional and structural criteria of characterized enzymes was proposed. ConclusionsPhysarum polycephalum sequences encompassing a chitinase like GH18 signature share a modular structure involving a structurally conserved catalytic TIM barrels decorated or not by a chitin insertion domain and optionally surrounded by additional sugar binding domains. One of them plays a clear role in enhancing activities toward natural chitin. General significanceMyxomycete enzymes are currently poorly characterized and constitute a potential source for new catalysts. Among them glycosyl hydrolases have a strong potential for valorization of industrial waste as well as in therapeutic field.

Brown Algal Residue for the Recovery of Metal Ions—Application to La(III), Cd(II), and Ni(II) Sorption

AbstractRemoving hazardous metals and recovering valuable strategic metals from wastewater has become an important challenge for the industry. Herein, brown algal biomass residue (AR, after bio‐stimulant extraction, currently poorly valorized) is tested for the removal of Ni(II), Cd(II), and La(III) from aqueous solutions. This valorization of industrial waste makes profit of residual amounts of alginate‐based materials, which have a strong affinity for metal cations. Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) techniques are used for characterizing metal/biosorbent interactions. Uptake kinetics are relatively fast (equilibrium being reached in 180–240 min). The Sips equation fits the sorption isotherms; the maximum sorption capacities at pH ≈5 reach up to 0.84 mmol La g−1, 0.92 mmol Cd g−1, and 0.78 mmol Ni g−1. In binary solutions, AR shows marked preference for La(III) over divalent cations. This selectivity may be increased by complexing base metals with EDTA, opening the route for the selective recovery of rare earth elements. HCl solution reveals more efficient (>90% for La(III), ≈82% for Cd(II) and Ni(II)) than CaCl2 solution at pH 2 for metal desorption. This waste residue from biostimulant extraction (in brown algal biomass) can be valorized for the recovery of hazardous and strategic metal ions.

Valorization of Industrial Waste for the Development of Fire-Resistant Materials

Valorization of Industrial Waste for the Development of Fire-Resistant Materials

Ceramic shell waste valorization: A new approach to increase the sustainability of the precision casting industry from a circular economy perspective

The problem of waste generation has grown because of the need to extract natural resources, obtain materials, and consume energy to meet current societal needs. Many studies have been conducted worldwide in favor of technological solutions for the valorization of industrial waste (IW) but few discussed relevant data for effective recovery. In this study, a case study of ceramic shell waste (CSW) was performed using, for the first time, a waste valorization system based on the classification, potentiality, quantity/viability, and applicability criteria (CPQvA) in a specific region (Brazil). CPQvA is a multicriteria decision-making system that acts as a guide to help managers and researchers connect the potential of IW with the feasibility of its application in a product or another process. Using the proposed systematic criteria, it was possible to demonstrate similarities and differences in waste applications. Thirteen possible products made from CSW were analyzed based on all the parameters of CPQvA. Ceramic filters and refractory aggregates were the most viable products. Creating public policies that encourage the use of waste as a raw material could make the precision casting industry process cleaner and the economy more circular.

Plasma and Superconductivity for the Sustainable Development of Energy and the Environment

The main aim of this review is to present the current state of the research and applications of superconductivity and plasma technologies in the field of energy and environmental protection. An additional goal is to attract the attention of specialists, university students and readers interested in the state of energy and the natural environment and in how to protect them and ensure their sustainable development. Modern energy systems and the natural environment do not develop in a sustainable manner, thus providing future generations with access to energy that is generated from renewable sources and that does not degrade the natural environment. Most of the energy technologies used today are based on non-renewable sources. Power contained in fuel is irretrievably lost, and the quality of the energy is lowered. It is accompanied by the emissions of fossil fuel combustion products into the atmosphere, which pollutes the natural environment. Environmental problems, such as the production of gaseous and solid pollutants and their emission into the atmosphere, climate change, ozone depletion and acid rains, are discussed. For the problem of air pollution, the effects of combustion products in the form of carbon oxides, sulfur and nitrogen compounds are analyzed. The plasma and superconductivity phenomena, as well as their most important parameters, properties and classifications, are reviewed. In the case of atmospheric pressure plasma generation, basic information about technological gas composition, pressure, discharge type, electromagnetic field specification, electrode geometry, voltage supply systems, etc., are presented. For the phenomenon of superconductivity, attention is mainly paid to the interdependencies between Tc, magnetic flux density Bc and current density Jc parameters. Plasma technologies and superconductivity can offer innovative and energy-saving solutions for power engineering and environmental problems through decreasing the effects of energy production, conversion and distribution for the environment and by reductions in power losses and counteracting energy quality degradation. This paper presents an overview of the application of technologies using plasma and superconductivity phenomena in power engineering and in environmental protection processes. This review of plasma technologies, related to reductions in greenhouse gas emissions and the transformation and valorization of industrial waste for applications in energy and environmental engineering, is carried out. In particular, the most plasma-based approaches for carbon oxides, sulfur and nitrogen compounds removal are discussed. The most common plasma reactors used in fuel reforming technologies, such as dielectric barrier discharge, microwave discharge and gliding-arc discharge, are described. The advantages of solid waste treatment using plasma arc techniques are introduced. Applications of superconductors for energy generation, conversion and transmission can be divided into two main groups with respect to the conducted current (DC and AC) and into three groups with respect to the employed property (zero resistivity, ideal magnetism/flux trapping and quench transition). Among the superconductivity applications of electrical machines, devices for improving energy quality and storage and high field generation are described. An example that combines the phenomena of hot plasma and superconductivity is thermonuclear fusion. It is a hope for solving the world’s energy problems and for creating a virtually inexhaustible, sustainable and waste-free source of energy for many future generations.

Closing the Loop Valorization of Industrial Waste of Composite Materials through Re-Design of Products from Detached Value Chains

AbstractThe literature lacks methodologies to make supply chains of composite materials circular. The proposed approach aims to transform scraps and off-specification products into secondary raw materials. Its novelty is to find innovative applications, instead of re-introducing scraps in the loop they come from. The case study investigates how scraps can be re-worked and re-used as raw material. First, the processes are analyzed; some components are then re-designed to be made of the discarded scraps (composites material). Results reveal that the symbiosis can ensure green, high performing products.

Recovery of Cork Manufacturing Waste within Mortar and Polyurethane: Feasibility of Use and Physical, Mechanical, Thermal Insulating Properties of the Final Green Composite Construction Materials

The valorization of industrial waste is a hot topic toward circular economy and sustainability. Several wastes have been proposed as resources for different production processes; however, others are still disposed to landfill or waste-to-energy plants. For the first time, this work suggests a sustainable alternative to managing cork waste from bottle caps manufacturing; this is generated by a local company at about 220,000 m3/year. The powder waste has a 0.063–1 mm particle size and is mainly composed of cork, polyurethane adhesive, and paraffin. Its valorization is proposed as filler in construction materials such as lime-based mortar (1–4 wt%) and polyurethane (5–15 wt%). Thermal, spectroscopic, and physical characterizations are performed on the cork waste, and mainly result in a low apparent density (340 kg/m3) and high-water absorption (177%). Cork properties allow consideration of extra water in the mortar mix and improve lightness without significantly affecting compressive, bending strength, and thermal insulation. Cork waste in polyurethanes promotes a color change, slightly increases the density (up to 12.5%), and still results in producing a thermally insulating material (<0.06 W/mK). Considering the promising results, this study demonstrates the feasibility of using the manufacturing waste from cork bottle caps to produce green construction materials, thus upgrading it from waste to secondary raw material.

A Sustainable Process to Produce Manganese and Its Alloys through Hydrogen and Aluminothermic Reduction

Hydrogen and aluminum were used to produce manganese, aluminum–manganese (AlMn) and ferromanganese (FeMn) alloys through experimental work, and mass and energy balances. Oxide pellets were made from Mn oxide and CaO powder, followed by pre-reduction by hydrogen. The reduced MnO pellets were then smelted and reduced at elevated temperatures through CaO flux and Al reductant addition, yielding metallic Mn. Changing the amount of the added Al for the aluminothermic reduction, with or without iron addition led to the production of Mn metal, AlMn alloy and FeMn alloy. Mass and energy balances were carried out for three scenarios to produce these metal products with feasible material flows. An integrated process with three main steps is introduced; a pre-reduction unit to pre-reduce Mn ore, a smelting-aluminothermic reduction unit to produce metals from the pre-reduced ore, and a gas treatment unit to do heat recovery and hydrogen looping from the pre-reduction process gas. It is shown that the process is sustainable regarding the valorization of industrial waste and the energy consumptions for Mn and its alloys production via this process are lower than current commercial processes. Ferromanganese production by this process will prevent the emission of about 1.5 t CO2/t metal.

Optimization of ultrasound-assisted liquefaction of solid digestate to produce bio-oil: Energy study and characterization

Among the possibilities for industrial waste valorization, liquefaction is gaining interest as it may provide alternative energy and high value-added products. In this context, this work focuses on the production of bio-oil through ultrasound (US)-assisted direct liquefaction. For the reaction, polyethylene glycol (PEG) and crude glycerol were selected. As this process is conducted by raising reaction temperature, US provided it, while shortening reaction time, through the cavitation phenomenon. For liquefaction reaction optimization, a response surface methodology (Box-Behnken design) was performed. As independent variables, US-amplitude, reaction time and solvent-to-biomass ratio were selected. On the other side, bio-oil yield, high calorific value (HCV) and energy consumption were chosen as dependent responses. Optimal results showed a bio-oil yield of 34.17% (reached in<20 min), HCV of 28.44 MJ/kg and energy consumption (US) of 11.477 kJ. Moreover, differences between predicted and experimental values were found to be negligible. Bio-oil was also characterized using Fourier transform infrared (FT-IR) and chromatography-mass spectrometry gas (GC–MS). Both techniques showed a profile rich in phenols and poly-oils, which can be used as precursors for industrial products, i.e. polymers. Finally, to check the impact of liquefaction on solid digestate, scanning electron microscopy (SEM) analysis was carried out. Results showed an increase in porosity, fragment and conglomerate. It may be concluded that the use of US as auxiliary energy in solid digestate liquefaction, to produce bio-oil, provides energy saving. Thus, the proposed valorization path aids consolidating the concept of circular economy through an efficient biorefinery model.

Avocado Peels and Seeds: Processing Strategies for the Development of Highly Antioxidant Bioplastic Films.

The industrial processing of avocados annually generates more than 1.2 million tons of avocado peels (APs) and avocado seeds (ASs) that have great potential in the production of active bioplastics, although they have never been considered for this aim until now. Separately, the APs and ASs, as well as a combination of avocado peels and seeds (APSs), were evaluated here for the first time for the preparation of antioxidant films, with application in food packaging. Films were prepared by casting, after their processing by three different methods: (1) hydrolysis in acid media, (2) hydrolysis followed by plasticization, and (3) hydrolysis and plasticization followed by blending with pectin polymers in different proportions (25 and 50 wt %). The results indicate that the combination of hydrolysis, plasticization, and pectin blending is essential to obtain materials with competitive mechanical properties, optical clarity, excellent oxygen barrier properties, high antioxidant activity, biodegradability, and migration of components in TENAX suitable for food contact applications. In addition, the materials prepared with APSs are advantageous from the point of view of the industrial waste valorization, since the entire avocado wastes are used for the production of bioplastics, avoiding further separation processes for their valorization.

Polyhydroxyalkanoates and pigments coproduction by Arthrospira (Spirulina) platensis cultivated in crude glycerol

Valorization of industrial waste as an alternative carbon source for microalgae mixotrophic cultivation and co-production of high-value compounds are strategies to enhance the bioprocess revenue and make large-scale production of microalgae polyhydroxyalkanoates (PHAs) feasible, with these biopolymers as potential substitutes to conventional polymers, such as polypropylene (PP) and high-density polyethylene (HDPE). In this sense, the use of crude glycerol, a main byproduct of the biodiesel industry, is an alternative to reduce cultivation costs and, at the same time, to provide a biotechnological solution for the excess of this byproduct produced, approximately 10 wt% per biodiesel batch. Thus, this work evaluated the effect of pure and crude glycerol supplementation and nutrient depletion (N and P) on growth, total carotenoids, phycocyanin and PHAs content in Arthrospira platensis xenic cultures. The highest final biomass concentrations, 1.68 and 1.40 g L-1, and PHAs contents, 1.1 and 0.5 % were achieved by supplying a Zarrouk medium with 6.14 g L-1 of pure or crude glycerol, respectively. In spite of having its content reduced at 6.14 g L-1 of pure glycerol, phycocyanin still presents a reasonable content (4.2 %) in this condition and in crude glycerol at 3.07 g.L-1 attained the highest content (10.8 %). On the other hand, glycerol mixotrophic cultivations with simultaneous nutrient depletion (nitrogen or phosphorus) did not improve the accumulation of PHAs.

Treatment of fruit waste leachate using microbial fuel cell: Preservation of agricultural environment

A microbial fuel cell (MFC) was conceived to low electric power production in parallel to valorization of industrial wastes and environment preservation. It consisted of two compartments separated by polymer Nafion membrane, platinum grid as cathode catalyst and graphite rod inoculated with fruit leachate as bio-anode. Owing to its bio-compatibity with bacterial inoculum and chemical stability, Graphite Carbon (GC) was tested as carrier of biofilm using fruit waste inoculum. The maximum power density harvested with this electrode was about 20 mW.m−2 much greater than that obtained previously with a garden compost inoculum (i.e. 7 mW.m−2). The difference between the two values may be attributed to the bacterial nature of inoculum utilized. Impressively, upon the addition of 6 mL of fuel (sucrose), the soft porous graphite felt GF yielded voltage (260 mV) which was significantly higher than that of the hard smooth solid GC (i.e. 140 mV). This result makes in evidence the effect of adsorption of the electro-active biofilm onto the surface of the electrode. We ascribe therefore the enhanced power density to a more uniform spread out of the electro-active biofilm within the GF matrix, as verified by higher conductivity obtained with four probe method. The results reported herein highlight the importance of assessing the bio-catalytic activity towards the oxidation of the organic substrate to yield renewable low energy. The experimental data and the differences between the bio-anodes GC and GF were discussed in term of electrochemical techniques such as cyclic voltammetry, impedance spectroscopy and four-probe conductivity. Whatever the nature of the bio-anodes, the overall bacterial colonization still yields low values of clean electric energy compared to highly polluted energy obtained with an alkaline fuel cell.

High-performance humidity control coatings prepared from inorganic wastes

Valorization of industrial wastes in an economic and environmental-friendly way is important. In the present study, the preparation of humidity control coatings (HCCs), which is an energy-saving method to regulate indoor humidity, are developed by recycling inorganic sludges (i.e., enhancement silica fume (ESF) and spent fluid catalytic cracking catalysts (sFCCC)). Bassanite, kaolin, sodium silicates and acrylic resins are combined with ESF and sFCCC in different amounts to prepare HCCs. Experimentally, moisture adsorption–desorption performance of the HCCs increases as ESF increases. Moreover, the humidity control performance can be enhanced in the range of medium relative humidity (50–75%) upon the addition of sFCCC which results in the formation of more micropores in the HCCs. However, excessive amounts of sFCCC could reduce the moisture adsorbed capacities in the humidity range of 50–90% relative humidity due to the decrease of mesopore volume. As a result, the HCCs with 38% of ESF and 10% of sFCCC have the optima ratios of mesoporous and microporous structure showing the moisture adsorbed value and content of 309 g m−2 and 27.0%, respectively, which are much better than commercial coatings (58.7 g m−2 and 11.4%). Moreover, the prepared HCCs can reach the coating benchmark of level 2 (based on Japanese Industrial Standards (JIS A 1470-1)) at medium relative humidity range (50–75%). In the simulation tests with variable temperatures, the HCCs exhibit a narrow amplitude change of moisture (7% relative humidity) which is smaller than commercial coatings (11–13% relative humidity). Most importantly, the HCCs have good film hardness, 99.99% of antimicrobial efficacy and environmental friendliness according to the pencil, antibacterial activity and toxicity characteristic leaching procedure (TCLP) tests, respectively.

Enhanced valorization of industrial wastes for biodiesel feedstocks and biocatalyst by lipolytic oleaginous yeast and biosurfactant-producing bacteria

The lipolytic oleaginous yeast Yarrowia lipolytica and biosurfactant-producing bacteria Bacillus subtilis were used to improve the valorization of palm oil industrial wastes for lipids and lipases. Biosurfactant likely enhanced the performance of the yeast by modifying hydrophobic substrates and cell membrane permeability leading to an increase in substrate entry and also secretion of lipases. The secreted lipases and biosurfactant also synergistically enhanced the biodegradation of the wastes, especially the removal of hydrophobic compounds. The COD and oil removal were improved by 1.47 folds and 2.33 folds, respectively. Consequently, the yeast could grow better on the wastes and accumulate higher lipid content by 1.3–1.5 folds. The biosurfactant also positively affected saturated fatty acid contents in the yeast lipids which make them more suitable as biodiesel feedstocks with higher cetane number and better oxidative stability. This biological process not only improves the biodegradation of environmental pollution from industrial wastes but also lowers the production costs of lipids as biodiesel feedstocks and lipases as biocatalyst.