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Three patients with elevated blood lactate values are described. The first, despite moderate hyperlactatemia of 5.3 mEq./1. and severe acidosis with an arterial blood pH of 6.98, had no "excess lactate". In a second patient, moderate acidosis with a pH of 7.27 and blood lactate of 7.5 mEq./1., of which 33% was excess lactate, was found to be secondary to tissue hypoxia on an ischemic basis and preceded the onset of clinical shock by four hours. A third patient, diabetic and under treatment with phenformin hydrochloride, presented with many features suggestive of pulmonary embolism, including marked pulmonary hypertension. A diagnosis of idiopathic lactic acidosis was established when the arterial blood pH was found to be 6.77 and a blood lactate value of 14.2 mEq./1., 60% as excess lactate, was discovered in the absence of a demonstrable cause of tissue hypoxia. Exploration of the pulmonary vascular bed showed no sign of mechanical blockage. The diagnostic, therapeutic and prognostic value of measuring blood lactic acid, and of quantitating the proportion circulating as "excess lactate", is emphasized.

The scientific community has been drawn to variations of the processes aimed at obtaining cellulosic fibers. Deep eutectic solvents-like mixtures have been shown to be a potential and green replacement for pulping processes where, in addition to cellulose fibers, lignin and hemicellulose are obtained as by-products. In this research, the treatment of softwood kraft pulp using deep eutectic solvents-like mixtures based on choline chloride and lactic acid was studied. We chose the temperature, the ratio of deep eutectic solvents-like mixtures to the input unbleached pulp, and the molar ratio between the components in the solvent as the studied operating conditions. As part of the chemical characterization, we analyzed the Kappa number, which indicates the remaining lignin in the fibers, followed by the calculation of the treatment efficiency. In addition, this process made it possible to obtain solid pulp under different conditions, which were characterized by analytical, optical, and spectrometric methods. The Kappa number of the delignified fibers ranged from 9.59 when using deep eutectic solvents-like mixtures in a ratio 1:9 (1 h; 120 °C; 1:10) to 20.88 (choline chloride/lactic acid 1:6; 1 h; 80 °C; 1:5), which represents treatment efficiency values from 6.79 % to 57.19 %.

Hemp fibers are promising biomaterials that have many advantages, such as biodegradability, low production costs, and rapid growth. They can be used as alternatives to other cellulosic fibers that have higher environmental impacts. However, to use hemp fibers effectively, they need to be separated from the lignin in the hemp biomass. This process is called delignification, and it is usually done by using harsh chemicals that are harmful to the environment and human health. In this work, we used a new and green solvent, called deep eutectic solvent-like mixtures, to delignify hemp biomass. Deep eutectic solvent-like mixtures are made from choline chloride and lactic acid, which are cheap, safe, and biodegradable. We tested different combinations of temperature (80–160 °C), time (60–240 min.), and solvent amount (1:10–1:60) to find the best conditions for delignification. We measured the Kappa number, which indicates how much lignin is left in the fibers, and the efficiency of delignification, which indicates how much lignin is removed. The Kappa number of delignified hemp fibers ranged from 10.7 (144 °C, 204 min, 1:30) to 21.8 (160 °C, 150 min, 1:17). The results showed that the optimal conditions to obtain the smallest Kappa number representing 6.6 are the boundary conditions of 160 °C, 240 min, and a ratio of 1:60. This method is more sustainable and environmentally friendly than the conventional methods, and it can help achieve the goal of sustainable development for mankind.

This paper discusses the fabrication of three-dimensional dendritic Ag nanostructures, showcasing pronounced Localized Surface Plasmon Resonance (LSPR) effects. These nanostructures, employed in surface-enhanced Raman scattering (SERS), function as sensors for lactic acid in artificial sweat. The dendritic structures of the silver nanoparticles (AgNPs) create an effective SERS substrate, with additional hotspots at branch junctures enhancing LSPR. We achieve differential LSPR effects by varying the distribution and spacing of branches and the overall morphology. Adjustments to electrodeposition parameters, such as current and plating solution protective agents on an anodized aluminum oxide (AAO) base, allow for precise control over LSPR intensities. By pre-depositing AgNPs, the electron transmission paths during electrodeposition are modified, which leads to optimized dendritic morphology and enhanced LSPR effects. Parameter optimization produces elongated rods with main and secondary branches, covered with uniformly sized, densely packed, non-overlapping spherical AgNPs. This configuration enhances the LSPR effect by generating additional hotspots beyond the branch tips. Fine-tuning the electrodeposition parameters improved the AgNPs’ morphology, achieving uniform particle distribution and optimal spacing. Compared to non-SERS substrates, our structure amplified the Raman signal for lactic acid detection by five orders of magnitude. This method can effectively tailor SERS substrates for specific analytes and laser-based detection.

Dihydroxyacetone isomerization is a fundamental reaction for the production of lactic acid using different feedstocks. However, achieving excellent catalytic activity and resistance against leaching in water is challenging. Herein, we devised a Sn doped zirconium phosphate as effective heterogeneous catalyst. The incorporation of Sn could remarkably aggrandize the content of strong Lewis acid sites while retain relatively high surface areas. Gratifyingly, this catalyst exhibits enhanced activity and reusability for selective dihydroxyacetone isomerization into lactic acid with water as solvent. High lactic acid yields of 70.30 and 76.25% were achieved in water and water/acetone under optimal reaction conditions, respectively. The composition and activity of catalyst are reserved with reduced ions leaching. The excellent catalytic performance is attributed to accelerated conversion of pyruvaldehyde to lactic acid by the strong Lewis acid sites. Nuclear magnetic resonance revealed that the reaction is proceeded via a keto-enol tautomerization process.

Cheese whey is a byproduct of the cheese industry that causes high levels of pollution in the environment, but its high lactose content means that it can be used as a source to obtain lactic acid. In this study, two strains, one belonging to a yeast and the other one to a bacteria (Kluyveromyces lactis and Enterococcus faecalis), were isolated from cheese whey and molecularly characterized, and the optimal growth conditions were determined. Then, using proteinized and deproteinized cheese whey, batch fermentation was carried out with the strains arranged in suspension and immobilized. The consumption of lactose and the production of lactic acid were measured through Brix degrees and acidity analysis. Afterwards, the lactic acid was purified, and its yield and physical and chemical characteristics were determined. It was proven that there were differences between each of the strains; arranged in free or encapsulated cells, the proteinized and deproteinized cheese wheys, under the same purification conditions, achieved different yields, colors, and densities of lactic acid. Immobilized Enterococcus faecalis had the highest yield (50.61 ± 34.94 g/L) using the deproteinized cheese whey compared to the immobilized Kluyveromyces lactis (35.70 ± 0.15 g/L) using the proteinized cheese whey.

Copper (I, II) oxide powders were tested for glycerol conversion to lactic acid under alkaline conditions. Fresh and spent catalysts were characterized using powder X-ray diffraction, Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy, the BET-nitrogen adsorption method and FTIR spectroscopy. In all cases, an almost complete in situ reduction of Cu (I, II) oxides into metallic Cu was observed, even after one catalytic run. Moreover, all the samples of spent catalysts showed similar catalytic activity regardless of their initial form and particle size. Commercial copper powders, prepared copper powders and in situ reduced copper catalysts were tested under the same conditions to compare their catalytic activity. It was shown that the in situ reduced copper catalyst had similar activity to the specially prepared copper powders and much higher activity compared to the commercial copper powders. The in situ reduced copper catalyst exhibited rather high stability. The glycerol conversion and lactic acid selectivity were about 98% and 70%, respectively, after ten catalytic cycles.

Cu-Zn MOF derived Cu-ZnO@C catalysts were developed and investigated for glycerol conversion to lactic acid in nitrogen gas. Full conversion of glycerol with 83.2% of lactic acid selectivity was realized for the Cu-ZnO@C-1.4-750 catalyst for 1 h at 220 oC. The Cu-ZnO@C-1.4-750 catalyst could be reused for 5 runs without regeneration treatment and slight deactivation occurs. Various characterization techniques were adopted to characterize the used catalyst. The active sites are verified to be Cu0 and Cu+ species. The high activity and size stability of the Cu-ZnO@C-1.4-750 catalyst are ascribed to highly dispersed Cu0/Cu+ species, proper Cu-ZnO interfaces and C coating.

A series of Zr-based catalysts were prepared using various commercial and cheap organic acids as the coordination agents, and these as-synthesized samples exhibited superior activities to produce lactic acid (LaA) from carbohydrates. Using humic acid (HA) as a typical coordination agent, LaA yield was up to 76% over the resultant Zr-HA, outperforming the most recent reported works. Deeper studies revealed that Zr-HA possessed both acid sites and base sites, and these dual active sites can simultaneously activate xylose, resulting in high yield production of LaA. Besides, Zr-HA also showed excellent reusability and can be reused at least five times.

The primary objective of this research was to develop efficient solid catalysts that can directly convert the lactic acid (LA) obtained from lignocellulosic biomass into alanine (AL) through a reductive amination process. To achieve this, various catalysts based on ruthenium were synthesized using different carriers such as multi-walled carbon nanotubes (MWCNTs), beta-zeolite, and magnetic nanoparticles (MNPs). Among these catalysts, Ru/MNP demonstrated a remarkable yield of 74.0% for alanine at a temperature of 200 °C. This yield was found to be superior not only to the Ru/CNT (55.7%) and Ru/BEA (6.6%) catalysts but also to most of the previously reported catalysts. The characterization of the catalysts and their catalytic results revealed that metallic ruthenium nanoparticles, which were highly dispersed on the external surface of the magnetic carrier, significantly enhanced the catalyst’s ability for dehydrogenation. Additionally, the -NH2 basic sites on the catalyst further facilitated the formation of alanine by promoting the adsorption of acidic reactants. Furthermore, the catalyst could be easily separated using an external magnetic field and exhibited the potential for multiple reuses without any significant loss in its catalytic performance. These practical advantages further enhance its appeal for applications in the reductive amination of lactic acid to alanine.

In order to develop a 2nd generation polylactic acid (PLA) process, lactide (LD) was synthesized directly from a commercially available 90% aqueous lactic acid (LA) solution. Experiments were conducted in an ordinary continuous flow fixed bed reactor. The reaction was carried out over various zeolites and γ-Al2O3 catalysts. Furthermore, the influence of pressure, temperature and water content in the inlet was studied. The highest LD selectivity of 98.9% was obtained using 90% LA and γ-Al2O3 as catalyst. In addition, it is concluded that LD yield increases when using highly concentrated LA oligomer with a minor amount of water. The catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray powder diffraction (XRD), nitrogen adsorption isotherms (BET), temperature programmed desorption of ammonia (NH3-TPD) and pyridine Fourier transformed infrared spectroscopy (Py-FTIR).

The effect of fingerprint sweat deposits on the detection efficiency of trace amounts of RDX, dinitronaphthalene, 2,4-dinitrotoluene, pentaerythritol tetranitrate, tetryl, 1,3,5-trinitrobenzene, trinitroresorcinol, 2,4,6-trinitrotoluene, and 2,4,6-trinitrophenol is studied by atmospheric pressure chemical ionization ion mobility spectrometry in the negative ion mode in air. Lactic (2-hydroxypropanoic) acid is the main component of the fingerprint that can possess this effect. The presence of lactic acid or a fingerprint in the sample does not significantly affect the efficiency of tetryl detection; although it changes the qualitative composition of pentaerythritol tetranitrate and RDX ions, causing the appearance of intense peaks in the spectrum, presumably, adducts of ions of these substances with lactic acid molecules, and dramatically impairs the efficiency of the formation of ions of other explosives. The limits of detection for trace amounts of RDX, dinitronaphthalene, 2,4-dinitrotoluene, pentaerythritol tetranitrate, tetryl, 1,3,5-trinitrobenzene, trinitroresorcinol, and 2,4,6-trinitrotoluene are 1, 2.5, 3, 4, 0.7, 5, 20, and 0.5 ng, and in the presence of a fingerprint with abundant sweat deposits, their values are 0.5, 2000, 1 x 10.sup.5, 2, 0.7, 5000, 300, and 100 ng, respectively. The limit of detection for 2,4,6-trinitrophenol is 30 ng; in the presence of a fingerprint, its value has not been determined., Author(s): T. I. Buryakov [sup.1], I. A. Buryakov [sup.1] Author Affiliations: (1) Alexandrov Research Technological Institute, , 188540, Sosnovy Bor, Leningradskaya oblast, Russia The simplest, most sensitive, and widespread methods [...]

The utilization of topical formulations containing alpha hydroxy acids (AHAs) has garnered considerable attention. This review summarizes the effectiveness of the most common topical AHA formulations, including mechanisms of action and future research directions. AHAs have a dramatic impact on diverse skin conditions, enhancing texture and stimulating collagen synthesis. Uncertainties persist regarding optimal concentration, pH, and vehicle for maximum efficacy. Advancements in formulation technologies offer opportunities for AHA penetration and stability. Understanding mechanisms is vital for skincare optimization. The review covers AHAs, their concentrations, formulation considerations, safety measures, and future directions.

Lactic acid is a naturally existing organic acid, which may be used in many different branches of industrial application. It can be made in the sugar fermentation process from renewable raw lactic acid, which is an indispensable raw material, including in the agricultural, food, and pharmaceutical industries. It is an ecological product that has enjoyed great popularity in recent years. In 2010, the US Department of Energy published a report about lactic acid to be a potential building element for future technology, whose demand grows year by year. The lactic acid molecule naturally exists in plants, microorganisms, and animals and can also be produced by carbohydrate fermentation or chemical synthesis from coal, petroleum products, and natural gas. In industry, lactic acid can be produced by chemical synthesis or fermentation. Although racemic lactic acid is always produced chemically from petrochemical sources, the optically pure L(+) – or D(−) – lactic acid forms can be obtained by microbial fermentation of renewable resources when an appropriate microorganism is selected. Depending on the application, one form of optically pure LA is preferred over the other. Additionally, microbial fermentation offers benefits including cheap renewable substrates, low production temperatures, and low energy consumption. Due to these advantages, the most commonly used biotechnological production process with the use of biocatalysts, i.e., lactic acid bacteria. The cost of raw materials is one of the major factors in the economic production of lactic acid. As substrate costs cannot be reduced by scaling up the process, extensive research is currently underway to find new substrates for the production of LA. These searches include starch raw materials, lignocellulosic biomass, as well as waste from the food and refining industries. Here, the greatest attention is still drawn to molasses and whey as the largest sources of lactose, vitamins, and carbohydrates, as well as glycerol – a by-product of the biodiesel component production process. Focusing on the importance of lactic acid and its subsequent use as a product, but also a valuable raw material for polymerization (exactly to PLA), this review summarizes information about the properties and applications of lactic acid, as well as about its production and purification processes. An industrial installation for the production of lactic acid is only planned to be launched in Poland. As of today, there is no commercial-scale production of this bio-raw material. Thus, there is great potential for the application of the lactic acid production technology and research should be carried out on its development.

Three types of CuO with different micro–structures were applied to catalyze the conversion of glycerol to lactic acid. The structure–activity relationship between CuO and its catalytic performance was investigated by combining experiments and theoretical calculations. We demonstrated that two CuO samples (CuO–BCC and CuO–CA), as prepared by calcining copper salts, show larger lattice spacing than that of commercial CuO (CuO–COM). In the catalytic experiments, CuO–BCC, which had the largest lattice spacing (d = 0.2480 nm), exhibited the highest yield of 78.54% for lactic acid. The lattice strain caused by lattice expansion was considered more favorable for CuO–BCC in adsorbing glycerol molecules, thereby improving the conversion of glycerol to lactic acid. The DFT simulation calculation results further prove that CuO–BCC has a larger adsorption energy for glycerol and a smaller thermodynamic energy barrier for the dehydrogenation of glycerol to form the key intermediate products (glyceraldehyde and 1,3-dihydroxyacetone) than CuO–COM. This study demonstrates the role of lattice strain effects in the development of catalysts and provides ideas for catalytic glycerol-selective oxidation studies.

L-polylactic acid (PLA), a semi–crystalline aliphatic polyester, is one of the most manufactured biodegradable plastics worldwide. The objective of the study was to obtain L-polylactic acid (PLA) from lignocellulosic plum biomass. Initially, the biomass was processed via pressurized hot water pretreatment at a temperature of 180 °C for 30 min at 10 MPa for carbohydrate separation. Cellulase and the beta-glucosidase enzymes were then added, and the mixture was fermented with Lacticaseibacillus rhamnosus ATCC 7469. The resulting lactic acid was concentrated and purified after ammonium sulphate and n-butanol extraction. The productivity of L-lactic acid was 2.04 ± 0.18 g/L/h. Then, the PLA was synthesized in two stages. Firstly, lactic acid was subjected to azeotropic dehydration at 140 °C for 24 h in the presence of xylene, using SnCl2 (0.4 wt.%) as a catalyst, resulting in lactide (CPLA). Secondly, microwave-assisted polymerization was carried out at 140 °C for 30 min with 0.4 wt.% SnCl2. The resulting powder was purified with methanol to produce PLA with 92.1% yield. The obtained PLA was confirmed using electrospray ionization mass spectrometry, nuclear magnetic resonance, thermogravimetric analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. Overall, the resulting PLA can successfully replace the traditional synthetic polymers used in the packaging industry.

Catalytic transformation of low-cost glycerol to value-added lactic acid (LA) is considered as one of the most promising technologies for the upgradation of glycerol into renewable products. Currently, research studies reveal that anaerobic transformation of glycerol to LA could also obtain green H2 with the same yield of LA. However, the combined value-added utilization of released H2 with high selectivity of LA during glycerol conversion under mild conditions still remains a grand challenge. In this perspective, for the first time, we conducted a comprehensive and critical discussion on current strategies for combined one-pot/tandem dehydrogenation of glycerol to LA with catalytic transfer hydrogenation of H2 acceptors (such as CO2) to other chemicals. The aim of this overview was to provide a general guidance on the atomic economic reaction pathway for upgrading low-cost glycerol and CO2 to LA as well as other chemicals.

Abstract Although chitin, an N‐acetyl‐D‐glucosamine polysaccharide, can be converted to valuable products by means of homogeneous catalysis, most of the chitin generated by food processing is treated as industrial waste. Thus, a method for converting this abundant source of biomass to useful chemicals, such as lactic acid, would be beneficial. In this study, we determined the catalytic activities of various metal oxides for chitin conversion at 533 K and found that MgO showed the highest activity for lactic acid production. X‐ray diffraction analysis and thermogravimetry‐differential thermal analysis showed that the MgO was transformed to Mg(OH)2 during chitin conversion. The highest yield of lactic acid (10.8 %) was obtained when the reaction was carried out for 6 h with 0.5 g of the MgO catalyst. The catalyst could be recovered as a solid residue after the reaction and reused twice with no decrease in the lactic acid yield.

The catalytic transformation of sugars into lactic acid has shown great potential for the scalable utilization of renewable biomass. Herein, RuOx/MoS2 catalysts were synthesized with the assistance of CaO for the one-pot conversion of glucose to lactic acid. Under the reaction conditions of 120 °C and 1 MPa O2, a 96.6% glucose conversion and a 54.3% lactic acid selectivity were realized in the one-pot catalytic reaction, with relatively high stability after four successive cycles. This catalytic system was also effective for the conversion of many other carbohydrate substrates, such as fructose, xylose and cellulose (selectivity 68.9%, 78.2% and 50.6%, respectively). According to catalyst characterizations and conditional experiments, the highly dispersed RuOx species on the surface of MoS2, together with OH−, promoted isomerization, retro-aldol condensation, dehydration and hydration reactions, resulting in a relatively high lactic acid yield for sugar conversions.

The second (lignocellulosic biomass and industrial wastes) and third (algal biomass) generation feedstocks gained substantial interest as a source of various value-added chemicals, produced by fermentation. Lactic acid is a valuable platform chemical with both traditional and newer applications in many industries. The successful fractionation, separation, and hydrolysis of lignocellulosic biomass result in sugars’ rich raw material for lactic acid fermentation. This review paper aims to summarize the investigations and progress in the last 5 years in lactic acid production from inexpensive and renewable resources. Different aspects are discussed—the type of raw materials, pretreatment and detoxification methods, lactic acid-producers (bacteria, fungi, and yeasts), use of genetically manipulated microorganisms, separation techniques, different approaches of process organization, as well as main challenges, and possible solutions for process optimization.

Burn wound healing involves a complex set of overlapping processes in an environment conducive to ischaemia, inflammation and infection costing $7.5 billion/year in the U.S.A. alone, in addition to the morbidity and mortality that occur when the burns are extensive. We previously showed that insulin, when topically applied to skin excision wounds, accelerates re-epithelialization and stimulates angiogenesis. More recently, we developed an alginate sponge dressing (ASD) containing insulin encapsulated in PLGA [poly(D,L-lactic-co-glycolic acid)] microparticles that provides a sustained release of bioactive insulin for >20 days in a moist and protective environment. We hypothesized that insulin-containing ASD accelerates burn healing and stimulates a more regenerative, less scarring healing. Using heat-induced burn injury in rats, we show that burns treated with dressings containing 0.04 mg insulin/cm(2) every 3 days for 9 days have faster closure, a higher rate of disintegration of dead tissue and decreased oxidative stress. In addition, in insulin-treated wounds, the pattern of neutrophil inflammatory response suggests faster clearing of the burned dead tissue. We also observe faster resolution of the pro-inflammatory macrophages. We also found that insulin stimulates collagen deposition and maturation with the fibres organized more like a basket weave (normal skin) than aligned and cross-linked (scar tissue). In summary, application of ASD-containing insulin-loaded PLGA particles on burns every 3 days stimulates faster and more regenerative healing. These results suggest insulin as a potential therapeutic agent in burn healing and, because of its long history of safe use in humans, insulin could become one of the treatments of choice when repair and regeneration are critical for proper tissue function.

Bakteri asam laktat memanfaatkan gula sebagai sumber energi, pertumbuhan, dan menghasilkan metabolit berupa asam laktat selama proses fermentasi. Gula berupa monomer glukosa dapat diperoleh dari hidrolisis atau pemutusan ikatan pada selulosa. Penelitian ini bertujuan untuk memproduksi asam laktat dari media selulosa menggunakan metode Simultaneous Saccharification and Fermentation (SSF). SSF diharapkan bermanfaat untuk pengembangan produksi asam laktat yang efektif dari limbah lignoselulosa. Pada tahap pertama, selulosa digunakan oleh Bacillus subtilis dan Bacillus circulans untuk memproduksi enzim selulase. Tahap kedua, enzim selulase kemudian digunakan untuk sakarifikasi selulosa menghasilkan glukosa. Glukosa yang diperoleh difermentasi oleh Lactobacillus delbrueckii menghasilkan asam laktat. Proses pada tahap kedua ini terjadi secara simultan, setelah itu proses fermentasinya digunakan metode SSF, dengan variasi konsentrasi enzim selulase untuk proses sakarifikasi berasal dari Bacillus subtilis dan Bacillus circulans. Proses awal pembuatan enzim selulase menggunakan bakteri Bacillus subtilis dan Bacillus circulans sebagai variabel dan waktu inkubasi selama 84 jam. Enzim selulase selanjutnya digunakan untuk mendegradasi media selulosa dalam proses SSF menjadi glukosa yang selanjutnya akan difermentasi oleh Lactobacillus delbrueckii. Pada proses SSF dengan inokulum Bacillus circulans diperoleh asam laktat tertinggi pada kadar enzim selulase 10% yaitu 1,29% dan dengan inokulum Bacillus subtilis pada kadar enzim selulase 5% yaitu 1,24%. Lactic acid bacteria use sugar as an energy source, growth, and produce metabolites in the form of lactic acid during the fermentation process. This research aimed to make lactic acid from cellulose used Simultaneous Saccharification and Fermentation (SSF). Cellulose is composed of glucose monomers. This method is expected to be useful for the development of significant lactic acid production from lignocellulosic waste. In the first stage, cellulose was used by Bacillus subtilis and Bacillus circulans to produce cellulase enzymes. In the second stage, the cellulase enzyme is then used to saccharify cellulose to produce glucose. The glucose fermented by Lactobacillus delbrueckii to produce lactic acid. The fermentation process uses the SSF method with various concentrations of cellulase enzymes. The initial process by making cellulase enzymes first used the bacteria Bacillus subtilis and Bacillus circulans as variables, and the incubation time was 84 hours. The cellulase enzyme is then used to degrade cellulose media in the SSF process into glucose, which will then be fermented by Lactobacillus delbrueckii. In the SSF process with Bacillus circulans inoculum, the highest lactic acid was obtained at 10% cellulase enzyme levels, amounting to 1.29%, and with Bacillus subtilis inoculums at 5% cellulase enzyme levels, amounting to 1.24%.

In this paper, the microwave-assisted synthesis of carboxymethyl cellulose-cl-poly(lactic acid–co-itaconic acid)/ZnO-Ag nanocomposite [CMC-cl-p(LA-co-IA)/ZnO-Ag] has been discussed. Lactic acid (LA) and itaconic acid (IA) monomers were grafted onto carboxymethyl cellulose (CMC) using potassium persulphate and N, N'-methylene-bis-acrylamide (MBA) as initiator and crosslinker, respectively at optimized conditions of temperature and pressure. The nanocomposite was characterized using different techniques such as Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and energy dispersive X-ray (EDX). XRD, TEM and FTIR spectral analysis confirmed the formation of the nanocomposite. The release of amoxicillin drug-using nanocomposite as a function of pH and time has been investigated. The maximum drug release of 94.64% was pragmatic at pH 2.2 after 6 h. The degradation of congo red using nanocomposite followed the pseudo-first-order reaction model with the regression coefficient (R2) values of 0.99312. The nanocomposite was also explored for anticancer behavior against yeast cells.

As a representative of traditionally fermented Chinese medicine, Massa Medicata Fermentata (MMF) shows the functions of invigorating the spleen and stomach and promoting digestion, which plays an important role in the treatment of gastrointestinal diseases. The fermentation mechanism and the key factors that affect the quality of MMF have not been revealed yet, which has become an urgent issue that limits its clinical application. This article aims to systematically and comprehensively reveal the transformation of physical properties and the dynamic trend of chemical components including substrate components, volatile components, and lactic acid as anaerobic fermentation product during MMF fermentation. Along with obvious hyphae growth observed for MMF, the weight of MMF decreased, and the moisture and temperature increased. Through the quantified 14 components from substrate, ferulic acid increased from 45.53 ± 6.94 to 141.89 ± 78.40 μg/g, while glycosides and phenolic acids declined except caffeic acid. Also, within the 66 volatile components analyzed, alcohols and acids increased, while aldehydes and ketones decreased. Lactic acid was not detected in the fermentation substrate, but an apparent increase in lactic acid content was observed along with the increased fermentation days, resulting in 2.54 ± 0.15 mg/g on day 8. Based on the tested components, the fermentation process of MMF was discriminated into three distinct stages by principal component analysis, and an optimal fermentation time of four days was proposed. The results of this study will be of great significance to clarify the characteristics of fermentation and conduce to improving quality standards of MMF.

Lactic acid is used for the preparation of poly-lactic acid. The objective of this research was to produce lactic acid from agro-industrial wastes as cheap, renewable substrates, and also reduce the pollution burden on the environment. Sixteen bacterial isolates were isolated from agro-industrial wastes. The chemical hydrolysis of agro-industrial wastes was achieved with hydrochloric acid, sulfuric acid, and sodium hydroxide. The highest yield of lactic acid produced was identified using 16S rRNA. The optimum conditions for lactic acid production were determined. Calcium lactate, produced from the culture fermentation was treated with sulfuric acid to precipitate the calcium sulfate. The filtrate holding free organic acid was vaporized to produce pure lactic acid. Chemical hydrolysis using 5% HCl released the highest concentration of total reducing sugar at 8015.90 and 7761.55 ​mg/L using cotton and coffee wastes, respectively. The bacterial isolate Kosakonia cowanii (B2) presented highest lactic acid concentration at 24.97 and 27.91 ​g/L after 24 and 48 ​h, respectively as a qualitative determined by HPLC analysis. The maximum lactic acid production at 28.14 ​g/L was obtained on the fermenter scale after 72 ​h by HPLC analysis.

The production of lactic acid and value-added chemicals (such as hydroxypropanone, glycolic acid, and formic acid) directly from Ulva prolifera via one-step catalytic process was studied. The effect of different amounts of YCl3-derived catalysts on the hydrothermal conversion of carbohydrates in Ulva prolifera was explored, and the reaction conditions were optimized. In this catalytic system, rhamnose could be extracted from Ulva prolifera and converted in situ into lactic acid and hydroxypropanone at 160 °C, while all the glucose, xylose, and rhamnose were fractionated and completely converted to lactic acid at 220 °C or at a higher temperature, via several consecutive and/or parallel catalytic processes. The highest yield of lactic acid obtained was 31.4 wt% under the optimized conditions. The hydrothermal conversion of Ulva prolifera occurred rapidly (within 10 min) and showed promise to valorize Ulva prolifera.

Acrylic acid is an important basic chemical and a key starting compound for a variety of consumer products. Today, acrylic acid is still produced from fossil-based propene. If acrylic acid were produced from bio-based lactic acid, this would be an important step towards sustainability. The gas-phase dehydration reaction of lactic acid to acrylic acid was performed over eight-membered ring PHI-type zeolites in the Na+ and K+-form. A few variations in the synthesis procedure of PHI-type zeolite made a big difference in the performance during the catalytic reaction due to differences in the physical and chemical properties, especially the accessibility of the pores. The catalysts were characterized with ICP-OES, XRD, CO2 physisorption, SEM and 27Al MAS NMR. The calcination resulted in a partial collapse of the PHI structure. In the case of Na,K-PHI with a low surface area, the catalysis tends to take place on the outer surface, while in the case of Na,K-PHI with a high surface area the catalysis can also take place within the pore system. This has a considerable influence on the selectivity of the catalysts.

Dental plaque, a complex biofilm system established by cariogenic bacteria such as Streptococcus mutans (S. mutans), is the initiator of dental caries. Studies have found that the cell-free supernatant (CFS) of Lactobacilli could inhibit S. mutans biofilm formation. However, the main antibiofilm substance of the Lactobacilli CFS that acts against S. mutans is unclear. The present study found that the CFS of Lactobacillus plantarum (L. plantarum) ATCC 14917 had the strongest antibiofilm effect among the five tested oral Lactobacilli. Further bioassay-guided isolation was performed to identify the main antibiofilm substance. The antibiofilm effect of the end product, named 1-1-4-3, was observed and the structure of it was elucidated by using Q-TOF MS, 2D NMR and HPLC. The results showed that several components in the CFS had an antibiofilm effect; however, the effect of 1-1-4-3 was the strongest, as it could reduce the generation of exopolysaccharides and make the biofilm looser and thinner. After structure elucidation and validation, 1-1-4-3 was identified as a mixture of lactic acid (LA) and valine. Additionally, LA was shown to be the main antibiofilm substance in 1-1-4-3. In summary, this study found that the antibiofilm effect of the L. plantarum CFS against S. mutans was attributable to the comprehensive effect of multiple components, among which LA played a dominant role.

Oral squamous cell carcinoma (OSCC) has a five-year survival rate of less than 50% due to its susceptibility to invasion and metastasis. Crosstalk between tumor cells and macrophages has been proven to play a critical role in tumor cell migration and invasion. However, the specific mechanisms by which tumor cells interact with macrophages have not been fully elucidated. This study sought to investigate the regulatory mechanism of tumor cell-derived alpha-enolase (ENO1) in the interaction between tumor cells and macrophages during OSCC progression. Small interfering RNA (siRNA) transfection and recombinant human ENO1 (rhENO1) stimulation were used to interfere with the interaction between tumor cells and macrophages. Our results showed that ENO1 was expressed higher in CAL27 cells than in HaCaT cells and regulated lactic acid release in CAL27 cells. Conditioned medium of macrophages (Macro-CM) significantly up-regulated the ENO1 mRNA expression and protein secretion in CAL27 cells. ENO1 promoted the migration and invasion of tumor cells by facilitating the epithelial–mesenchymal transition (EMT) through macrophages. ENO1 orchestrated the IL-6 secretion of macrophages via tumor cell-derived lactic acid and the paracrine ENO1/Toll-like receptor (TLR4) signaling pathway. In turn, IL-6 promoted the migration and invasion of tumor cells. Collectively, ENO1 promotes tumor cell migration and invasion by orchestrating IL-6 secretion of macrophages via a dual mechanism, thus forming a positive feedback loop to promote OSCC progression. ENO1 might be a promising therapeutic target which is expected to control OSCC progression.

A simple and rapid gas chromatographic-mass spectrometric (GC-MS) method using selected ion monitoring mode was developed for simultaneous determination of propylene glycol, glycerol and lactic acid in rat plasma and serum. The method employed a single-step derivatization using bis(N,O-trimethylsilyl) trifluoroacetamide with trimethylchlorosilane and required only a small amount of plasma or serum (100 [mu]L). The calibration curves showed linearity with the correlation coefficients of 0.996-0.999. To validate the method, the intra- and inter-day repeatability of the proposed method in rat plasma was evaluated. Recovery was assessed by the standard addition method. To test the applicability of the method, twenty plasma samples in two different time points were analyzed and levels of both propylene glycol and lactic acid in plasma were found to increase after exposure to the propylene glycol aerosol (500 mg/kg). With satisfactory repeatability and recovery the proposed GC-MS method can be successfully applied for analysis of plasma and serum samples., Author(s): Demin Liang [sup.1], Yihan Gao [sup.1], Saijing Zheng [sup.1], Gang Li [sup.1], Da Wu [sup.1], Yi Shen [sup.1] Author Affiliations: (1) Technical Center of Shanghai Tobacco Group Co. Ltd, [...]

Chitosan or its derivatives exhibit lyotropic liquid crystalline mesophases under certain conditions due to its semi-rigid structures. This work describes the development of chitosan-based biocompatible systems that include new components: lactic acid and non-ionic surfactants. Polarized optical microscopy studies revealed that these systems are capable of forming gels or lyotropic liquid crystals (LLCs) in a certain range of chitosan and lactic acid concentrations. According to the viscosity studies, the rheological flow of the LLCs can be accurately described by the Casson flow model. The intermolecular interactions of the LLC components were studied by FTIR spectroscopy. According to the FTIR data, hydrogen bonding is supposed to be responsible for the formation of the LLCs. In the studied systems, this LLC complex exists as the [ChitH+·CH3-CH(OH)-COO−] ion pair. The studied gel and LLCs were shown to possess the most prolonged release capabilities for riboflavin among similar binary LLC systems. The supramolecular organization and rheological characteristics of the studied chitosan-based systems were found to affect the release of riboflavin.

Capnophilic lactic fermentation (CLF) is an anaplerotic pathway exclusively identified in the anaerobic hyperthermophilic bacterium Thermotoga neapolitana, a member of the order Thermotogales. The CO2-activated pathway enables non-competitive synthesis of hydrogen and L-lactic acid at high yields, making it an economically attractive process for bioenergy production. In this work, we discovered and characterized CLF in Thermotoga sp. strain RQ7, a naturally competent strain, opening a new avenue for molecular investigation of the pathway. Evaluation of the fermentation products and expression analyses of key CLF-genes by RT-PCR revealed similar CLF-phenotypes between T. neapolitana and T. sp. strain RQ7, which were absent in the non-CLF-performing strain T. maritima. Key CLF enzymes, such as PFOR, HYD, LDH, RNF, and NFN, are up-regulated in the two CLF strains. Another important finding is the up-regulation of V-ATPase, which couples ATP hydrolysis to proton transport across the membranes, in the two CLF-performing strains. The fact that V-ATPase is absent in T. maritima suggested that this enzyme plays a key role in maintaining the necessary proton gradient to support high demand of reducing equivalents for simultaneous hydrogen and lactic acid synthesis in CLF.

Deep eutectic solvents (DESs) are considered as a green and environmentally benign solvent class for various applications, including delignification of biomass. One of the major challenges in the delignification of biomass by DES is attributed to the limitations in mass transfer. By subjecting wood chips to a low-energy mechanical refining, i.e., the Asplund process, the accessible surface area increases greatly, which in turn improves the mass transfer and increases the reaction rate. In this research, the DES delignification of Asplund fibers made of Norway spruce was studied as a strategy to produce papermaking fibers under mild conditions. A DES consisting of lactic acid and choline chloride was used due to its proven performance in delignification. Various operational conditions, such as temperature, time, DES-to-wood ratio, and the type of stirring were studied. A novel parameter, Q, allowed to evaluate the impact of the operational conditions on the quality of the pulp in terms of delignification degree and fiber length. The results showed that cooking temperature had the most significant effect on the pulp quality. Additionally, it was observed that cooking times between 30 and 45 min result in a pulp yield of about 50%, while fibers have a lignin content of about 14% and a fiber length of 0.6 mm. These results demonstrate that it is possible to obtain fibers of relatively good quality from DES delignification using Asplund fibers as the starting material.

Abstract Anatase nanowires were synthesized in solution by using a simple mixing of titanium diisopropoxide bis(acetylacetonate), lactic acid and sodium hydroxide at room temperature. We discuss effects of reaction parameters and post treatment (annealing) on the nanowire morphology, surface area, and crystallinity, as well as the competing morphology directing effects of lactic acid and sodium hydroxide. Then the room temperature nanowires were directly grown onto fluoride doped tin oxide (FTO) glass to form photoanodes. Photoelectrochemical measurements of the different nanowires were performed and compared to conventional nanowires produced by high temperature synthesis. Clearly the nanowires introduced in this work show a significant increase in the maximum photocurrent, compared to classic hydrothermal nanowire layers.

This paper is interested in mechanism of lactic acid (LA) adsorption and dehydration into acrylic acid (AA) over tin and iron beta zeolite (Sn- and Fe-BEA) catalysts. The electronic structure of clusters was calculated by ab initio density functional theory (DFT) method. The M2Si12O39H22 (hierarchical zeolite) and M2Si22O64H32 (ideal zeolite) clusters (M=Al, Si, Sn) were used in the LA dehydration reaction. The stabilization of the dimeric complex M-Ob-M (where M= Sn or Fe) in the BEA, ideal and hierarchical structure, was investigated. Possible modes of interaction of lactic acid with different cations (Si, Al, Fe or Sn) in the BEA zeolite framework as well as with added iron and tin dimers were considered. The interaction of lactic acid was only observed above the M-Ob-M dimer. The direct mechanism of lactic acid dehydration into acrylic acid was found over metal M-Ob-M dimers deposited at the BEA zeolite.

Photocatalysis provides a prospective approach for achieving high-value products under mild conditions. To realize this, constructing a selective, low-cost and environmentally friendly photocatalyst is the most critical factor. In this study, BiOBr/Zn@SnO2 is fabricated by a one-pot hydrothermal synthesis method and BiOBr: SnO2 ratio is 3:1; this material is applied as photocatalyst in fructose selective conversion to lactic acid. The bandgap structure can be regulated via two-step modification, which includes Zn doping SnO2 and Zn@SnO2 coupling BiOBr. The photocatalyst shows excellent conversion efficiency in fructose and high selectivity in lactic acid generation under alkaline conditions. The conversion rate is almost 100%, and the lactic acid yield is 79.6% under optimal reaction conditions. The catalyst is highly sustainable in reusability; the lactic acid yield can reach 67.4% after five runs. The possible reaction mechanism is also proposed to disclose the photocatalysis processes.

This study reports for lactic acid production from different carbohydrates; monosaccharide (glucose, galactose, lactose) & disaccharides (sucrose) and from lignocellulose biomass (rice straw) by a novel strain ‘Lactobacillus sp. strain TERI-D3’. ‘TERI-D3’ strain produced 19.9, 19.4, 18.1 and 15.8 ​g/L of lactic acid from glucose, sucrose, lactose and galactose, respectively. Maximum lactic acid yield efficiency (0.97 ​g/g) was observed with glucose (>95% of the theoretical maximum yield). Lactic acid titer from glucose was 0.41 ​g/L. The lactic acid titer and yield from rice straw biomass sugar was; 11.58 ​g/L and 0.73 ​g/g (>80% of the theoretical maximum yield), respectively. The novelty of this study is that the ‘TERI-D3’ strain is a promising microbe for green lactic acid as it has potential to valorize cheese industry waste, algae biomass as well as to utilize inexpensive next generation lignocellulose biomass that are abundant and do not compete with food chain supply. This approach of recycling and or reuse of organic waste holds importance in the circular economy frame.

In this study, Spirulina biochar obtained from fast pyrolysis was evaluated as an alternative to commercial activated carbon for lactic acid (LA) purification from a fermentation broth. Thermally (350 and 400 ​°C treatment of the biochar in N2 atmosphere for 4 ​h) and chemically (KOH solution impregnation of the algal material and fast pyrolysis to obtain the biochar) activated Spirulina biochars were also tested. The biochars were previously characterized using SEM and FT-IR. Two purification methodologies were evaluated: filtration and stirring. The stirring method prove to be simpler, faster and chipper, with excellent purification results. All the evaluated biochars presented a performance comparable to that of activated carbon in the stirring methodology. Spirulina biochar and the KOH activated biochar were the once with the best results, with 92 and 82% LA recovery and 82 and 90% protein removal efficiencies, respectively.

Accelerated glycolysis leads to secretion and accumulation of lactate and protons in the tumor environment and determines the efficacy of adoptive T cell and checkpoint inhibition therapy. Here, we analyzed effects of lactic acid on different human CD4 T cell subsets and aimed to increase CD4 T cell resistance towards lactic acid. In all CD4 T cell subsets analyzed, lactic acid inhibited metabolic activity (glycolysis and respiration), cytokine secretion, and cell proliferation. Overexpression of the lactate-metabolizing isoenzyme LDHB increased cell respiration and mitigated lactic acid effects on intracellular cytokine production. Strikingly, LDHB-overexpressing cells preferentially migrated into HCT116 tumor spheroids and displayed higher expression of cytotoxic effector molecules. We conclude, that LDHB overexpression might be a promising strategy to increase the efficacy of adoptive T cell transfer therapy.

Attempts to find and quantify the supposed low entropy of organisms and its preservation are revised. The absolute entropy of the mixed components of non-living biomass (approximately −1.6 × 103 J K−1 L−1) is the reference to which other entropy decreases would be ascribed to life. The compartmentation of metabolites and the departure from the equilibrium of metabolic reactions account for reductions in entropy of 1 and 40–50 J K−1 L−1, respectively, and, though small, are distinctive features of living tissues. DNA and proteins do not supply significant decreases in thermodynamic entropy, but their low informational entropy is relevant for life and its evolution. No other living feature contributes significantly to the low entropy associated with life. The photosynthetic conversion of radiant energy to biomass energy accounts for most entropy (2.8 × 105 J K−1 carbon kg−1) produced by living beings. The comparatively very low entropy produced in other processes (approximately 4.8 × 102 J K−1 L−1 day−1 in the human body) must be rapidly exported outside as heat to preserve low entropy decreases due to compartmentation and non-equilibrium metabolism. Enzymes and genes are described, whose control minimizes the rate of production of entropy and could explain selective pressures in biological evolution and the rapid proliferation of cancer cells.

One of the most interesting intermediates for the chemical industry is acrylic acid, which can be derived from lactic acid by catalytic dehydration in the gas phase. The realization of this reaction is complex due to a strong thermal activation leading to the formation of undesired by-products (acetaldehyde, propanoic acid…) as well as polymerization. We studied this reaction over hydroxyapatites modified by substitution of the hydroxyl groups by fluoride. This notably enabled increasing the selectivity to acrylic acid while reducing the formation of the undesired acetaldehyde. Introduction of fluoride induced a modification of the phosphate (PO43-) groups. In the presence of water, fluoride prevented the formation of hydrogenophosphate species (HPO42-), which are well-known acid sites responsible for the formation of acetaldehyde by decarboxylation/decarbonylation. Further, we evidenced an important impact of fluoride substitution on crystallinity, specific surface area and on the surface Ca/P ratio. This latter is known to be a key parameter to control the acidity and the basicity of the hydroxyapatites. Using FT-IR spectroscopy with propyne as a probe molecule, we could show that lactic acid was concertedly adsorbed on basic and acid sites, which might be at the origin of the observed superior performances.

The aim of this work was to develop the method of lactic acid (LA) separation from fermented whey. CMI-7000 Cation Exchange Membrane and AMI-7001 Anion Exchange Membrane were employed in electrodialysis process. Experiments showed that the selected membranes separated organic acids effectively (including LA) from other organic ingredients present in medium. Selecting an appropriate volume of a receiving chamber could lead to LA concentration. Moreover, membrane fouling during separation was investigated. This phenomenon is negligible which is the main advantage of this process. As it was shown during batch processes, with the voltage increase, the rate of electrodialysis increases as well. It prompts to a reduction of residence time in electrodialyzer during a continuous separation.

Avocado seeds starch was investigated after the modification with lactic acid using thermogravimetry and differential thermal analysis, differential scanning calorimetry, X-ray powder diffraction and scanning electron microscopy. After the modification, there was a decrease in the thermal stability of the starch, also the parameters measured by differential scanning calorimetry showed lower values. There was no difference in the morphology of the granules, which presented an oval and rounded shape.

Starch production is mainly focused on feedstocks such as corn, wheat and potato in the EU, whereas cassava, rice, and other feedstocks are utilised worldwide. In starch production, a high amount of wastewater is generated, which accumulates from different process steps such as washing, steeping, starch refining, saccharification and derivatisation. Valorisation of these wastewaters can help to improve the environmental impact as well as the economics of starch production. Anaerobic fermentation is a promising approach, and this review gives an overview of the different utilisation concepts outlined in the literature and the state of the technology. Among bioenergy recovery processes, biogas technology is widely applied at the industrial scale, whereas biohydrogen production is used at the research stage. Starch wastewater can also be used for the production of bulk chemicals such as acetone, ethanol, butanol or lactic acids by anaerobic microbes.