Enzymes are the large biomolecules that are required for the numerous chemical interconversions that sustain life. They accelerate all the metabolic processes in the body and carry out a specific task. Enzymes are highly efficient, which can increase reaction rates by 100 million to 10 billion times faster than any normal chemical reaction. Due to development in recombinant technology and protein engineering, enzymes have evolved as an important molecule that has been widely used in different industrial and therapeutical purposes. Microbial enzymes are currently acquiring much attention with rapid development of enzyme technology. Microbial enzymes are preferred due to their economic feasibility, high yields, consistency, ease of product modification and optimization, regular supply due to absence of seasonal fluctuations, rapid growth of microbes on inexpensive media, stability, and greater catalytic activity. Microbial enzymes play a major role in the diagnosis, treatment, biochemical investigation, and monitoring of various dreaded diseases. Amylase and lipase are two very important enzymes that have been vastly studied and have great importance in different industries and therapeutic industry. In this review, an approach has been made to highlight the importance of different enzymes with special emphasis on amylase and lipase in the different industrial and medical fields.
Hydroxyapatite is a versatile material with strong potential for environmental remediation, yet its large-scale use is limited by the cost and purity requirements of conventional precursors. This study introduces a low-cost and sustainable synthesis route for hydroxyapatite using technical-grade phosphoric acid, highlighting the beneficial role of industrial impurities in tuning its structural, optical, and adsorption properties, thus promoting its broader use in environmental applications. Hydroxyapatite powders were synthesized from calcium hydroxide and technical-grade phosphoric acid (Ca/P = 1.67) at 25 °C in aqueous medium, then dried and calcined (500–1100 °C). Structural, chemical, and optical analyses revealed single-phase nano-hydroxyapatite (12.6–57.3 nm) with high surface area (176.95 m²·g-1) and strong wettability. The optical band gap decreased from 4.5 ± 0.4 eV to 3.2 ± 0.4 eV after calcination, indicating defect-induced electronic modification. The poorly crystallized hydroxyapatite exhibited excellent Cd²⁺ and Pb²⁺ adsorption (99 % and 97 % removal in 100 min) but limited bisphenol A elimination (2.73 % in 180 min).
Fish waste consists of various substances that have the potential to pollute the environment. However, microalgae can absorb these substances and convert them into valuable biomass. This study is the first to investigate how mixed microalgae efficiently utilize nitrogen and phosphorus from wastewater as important nutrients for their propagation. The present study investigates a new approach to studying the effects of changing the light spectrum on the growth of mixed microalgae cultured in a fish waste-contaminated environment. The innovative method presented here involves the use of a 9,10-diphenylanthracene solution to treat fish wastewater by mixed microalgae, providing optimal photons to promote their growth. A special experimental setup was developed using a white LED lamp in a double-layered transparent tube filled with a 10,9-diphenylanthracene solution to manipulate the spectrum. This setup was carefully positioned in the center of an Erlenmeyer flask to ensure uniform light distribution. Aluminum foil was used to reflect the photons into the flask to avoid light loss. The results of the study showed a remarkable 230% increase in biomass productivity of mixed microalgae when this method was applied. Furthermore, the results obtained with the logistic and Gompertz growth models are in perfect agreement with the empirical findings and represent a pioneering achievement in modeling in this particular area.
A phase-change material (PCM) is recommended for thermal energy storage. However, conventional PCMs suffer from poor thermal conductivity. To solve this problem, this study presented different compositions to improve PCM thermal conductivity. The effects of the average specific surface of metal foams and the weight percentage of metal foams and hybrid nanoparticles on the phase-change materials' thermal characteristics were investigated. The findings demonstrate that thermal performance of the PCM composite is noticeably better than that of pure PCM and increasing the weight content of foam metal and hybrid nanoparticles leads to an increase in thermal conductivity of 37.7% for the same type of copper. The results also reveal that thermal conductivity performance increases as the amount of metal foam and hybrid nanoparticles increases. The average specific surface value of 1600 m2/m3 shows better thermal properties compared with other average specific surface values. Moreover, the heat capacity is affected by the increase in the content of metal foam. Many drawbacks have been found in using foam metal in PCM preparation, mainly the fixed shapes of metal foams compared with the formability nature of the PCM, which effects the shapes of the PCM composites and thus limits its use in applications with limited size. This novel approach to improving PCM's thermal behaviour may be applied to the creation of thermal energy storage devices with predetermined characteristics.
Vikas Sharma, Abul Kalam Hossain, Ganesh Duraisamy
et al.
By 2050, aviation-related carbon emissions are expected to quadruple to over 3000 million tonnes of carbon dioxide, so finding sustainable alternative solutions to minimise pollution is a key scientific challenge. Aviation gasoline and kerosene are currently used to power most jet engines. While battery-powered planes and planes that could utilise a cleaner fuel, such as hydrogen, are possible, the time scale required to improve and implement these technologies is distant, with air fleet turnover taking some 30 years. Existing jet engines could be modified to run on biodiesel, and considering the close similarity in fuel density to kerosene, could be a less disruptive approach to the industry. The sheer volume of biodiesel required remains a challenge, and certainly, using plant-derived oils grown on arable land is not acceptable, as it competes with food production. However, high-lipid-yielding microalgae (where productivity is an order of magnitude greater than oilseeds), grown on marginal land, such as desert or semi-desert areas of the world, could be possible. Indeed, to replace 30% of fossil fuel with algal-derived biodiesel would require 11,345 km<sup>2</sup> of land. Biodiesel preparation is well understood, but what is lacking is proven technology aimed at optimising microalgal production of oil at a much larger scale. Here, a synergic review of the current state-of-the-art in algal production, that includes strain selection, possible production sites, culturing costs, and harvesting to identify the bottlenecks in meeting the ASTM specifications for the aviation industry, is presented.
Łukasz Łopusiewcz, Natalia Śmietana, Elżbieta Lichwiarska
et al.
In recent years, there has been increasing consumer interest and research into plant-based dairy alternatives, due to the increasingly negative impact of animal products on human health, animal welfare, and the environment. The purpose of this study was to investigate the physicochemical and microbiological changes in a Camembert alternative based on the seeds of sweet lupine (<i>Lupinus angustifolius</i> L cv. ‘Boregine’). After heat treatment and homogenization, the seeds were incubated with lactic acid bacteria (LAB) and <i>Penicillium camemberti</i> mold. After fermentation at room temperature, the samples were stored at 12 °C for 14 days, and then ripened until day 49 at 6 °C. Changes in microbial population, acidity, texture, content of polyphenols, flavonoids, reducing sugars, and free amino acids were monitored. In addition, the antioxidant capacity of the samples during ripening was determined. The results showed that LAB and fungi were able to grow well in the lupine matrix. Initially, a decrease in pH was observed, while in the further stages of ripening, alkalization of the product linked with progressive proteolysis associated with an increase in free amino acid content was noted. Hydrolysis of polysaccharides and an increase in antioxidant activity were observed. This indicates the potential of lupine seeds as a raw material for the development of a new group of plant-based ripened cheese alternatives.
Natthiporn Aramrueang, Passanun Lomwongsopon, Sasiprapa Boonsong
et al.
Volatile fatty acids (VFAs) are the important intermediates indicating the stability and performance of fermentation process. This study developed the spectrophotometric method for determining high-range VFA concentration in mixed-acid fermentation samples. The performance was compared with the gas chromatography (GC) technique. The calibration curves of the modified method showed linearity over a wide and high concentration range of 250–5000 mg/L for individual C2–C6 VFAs in both linear and branched chains. In order to evaluate the modified method for VFA determination in complex fermentation matrices, fermentation samples produced from acidogenic fermentation of plant materials were spiked with acetic (500–1500 mg/L) and butyric acids (1000 mg/L). The accuracy and precision of the modified method for VFA determination were in the range of 94.68–106.50% and 2.35–9.26%, respectively, comparable to the GC method (94.42–99.13% and 0.17–1.93%). The developed method was applicable to measuring all C2–C6 compounds and VFA concentrations in the fermentation samples and had an acceptable accuracy and precision. The proposed method is analytically reliable and offers significant advantages in the rapid determination of VFAs in mixed acid fermentation of organic residues.
Getari Kasmiarti, Dwita Oktiarni, Poedji Loekitowati Hariani
et al.
Yeast is a fermentation agent for producing bioethanol as an environmentally friendly alternative energy. Therefore, this study aims to find novel yeasts with the capability to persevere under acidic, high temperature, and high sugar content conditions, which are required in the bioethanol industry. The yeasts were isolated and identified from coconut (<i>Cocos nucifera</i> L.) water by a DNA sequencing method and phenotypic test. Yeast isolation has been completed with a serial dilution procedure and purification was conducted with HiPurA Genomic DNA Purification Spin Kits, which were analyzed by DNA Sequencing. The phenotypic test was carried out with thermotolerant (30 °C and 41 °C), high acidity (lactic acid), and sugar content (molasses 35 °brix) parameters in the media as the initial step of yeast ability screening. Based on the results, the three species of <i>Candida tropicalis</i> K5 (<i>Candida tropicalis</i> strain L2), K15 (<i>Candida tropicalis</i> strain MYA-3404), and K20 (<i>Candida tropicalis</i> strain Y277) obtained met the phenotypic standards. This showed that the yeasts have the potential to produce molasses-based bioethanol.
Daniel Ursu, Anamaria Dabici, Marinela Miclau
et al.
We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 °C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.
de Lima Silva Paulo H., Naccache Mônica F., de Souza Mendes Paulo R.
et al.
One of the main issues in the area of drilling and production in deep and ultra-deep water in the oil industry is the formation of natural gas hydrates. Hydrates are crystalline structures resembling ice, which are usually formed in conditions of high pressure and low temperature. Once these structures are formed, they can grow and agglomerate, forming plugs that can eventually completely or partially block the production lines, causing huge financial losses. To predict flow behavior of these fluids inside the production lines, it is necessary to understand their mechanical behavior. This work analyzes the rheological behavior of hydrates slurries formed by a mixture of water and Tetrahydrofuran (THF) under high pressure and low temperature conditions, close to the ones found in deep water oil exploration. The THF hydrates form similar structures as the hydrates originally formed in the water-in-oil emulsions in the presence of natural gas, at extreme conditions of high pressure and low temperature. The experiments revealed some important issues that need to be taken into account in the rheological measurements. The results obtained show that the hydrate slurry viscosity increases with pressure. Oscillatory tests showed that elasticity and yield stress also increase with pressure.
Chemical technology, Energy industries. Energy policy. Fuel trade
Koen F. V. Parmentier, Koen F. V. Parmentier, Yves Verhaegen
et al.
The restrictions and the concerted action of the global ban on the use and presence of tributyltin (TBT) in marine applications to protect ecosystems in the marine environment in 2008 was mainly based on the economic impact on shellfish industries and the dramatic extinction of local mollusk populations in the past. In contrast to the vast datasets on effects on mollusks, the knowledge on impacts on species from other taxa remained in the uncertain until almost two decades ago. The assumption on a long-term TBT-mediated pernicious metabolic bottom–up regulation of the crustacean Crangon crangon population was provoked by the outcome of an EU-project ‘Sources, Consumer Exposure and Risks of Organotin Contamination in Seafood.’ This study reported high TBT body burdens in C. crangon in 2003, at the start of the transition period to the global ban. Experimental research on the TBT impact in C. crangon focused on agonistic interference with natural ecdysteroid hormones at the metabolic pathways regulating growth and reproduction and the biogeochemical distribution of the chemical. In this paper, metabolic, topical and population-relevant biological endpoints in C. crangon and other crustaceans are evaluated in relation to the temporal and spatial trends on TBT’s occurrence and distribution in the field during and after the introduction of the tributyltin restrictions and endocrine-related incidents. Arguments are forwarded to relate the German Bight incident on growth and reproduction failure in the C. crangon population, despite the lack of direct evidence, to the pernicious impact of tributyltin in 1990/91 and previous years. The extreme occurrence of TBT in C. crangon from other parts of the southern North Sea and evidence on the high body burdens as dose metrics of exposure also feeds the suspicion on detrimental impacts in those areas. This paper further demonstrates the complexity of distinguishing and assessing the individual roles of unrelated stressors on a population in an integrated evaluation at the ecosystem level.
Science, General. Including nature conservation, geographical distribution
The article deals with the integration of large and small businesses in order to increase mutual effectiveness. Currently, large business, mainly in form of transnational and national corporations, is the foundation of the economy on a global and national scale, dominating in international trade, high technology, infrastructure and nature-exploiting industries. However, large business does not have enough mobility, it appears unable to respond quickly to the environmental turbulence. In its turn, small business demonstrates the quick response to changes in the environment, but has less resistance to the disturbance of the environment, which makes it vulnerable to market challenges. The integration of large and small businesses will be useful for both sides. The forms of such integration may be different. However, in any case, it will entail synergistic and complementary effects. The overview of the Perm region's industry by sectors (fuel and chemical industry, machine building, agriculture, construction and transport complexes), which is provided in the article, leads to the conclusion that the region's economy, focused on large business, is going through hard times. The main idea of the article is that the integration of small and medium-sized businesses with large business of the Perm region will provide a complementary and synergistic effects, which will allow for implementing a strategy for the development of the Perm region based on stirring up the investment, innovation and modernization components of the region's production and economic complex. The presented structure of small business testifies to the possibility of the integration.