Alkaline pH Research Articles

Cyanotoxins bioaccumulation by fish in an anthropized reservoir in central Mexico

The bioaccumulation of cyanotoxins has been well documented in exposed organisms including fish, which represent a potential route to cyanotoxins transfer to humans by consumption of contaminated food. We determined the bioaccumulation of neurotoxic saxitoxins and hepatotoxic microcystins in muscle and liver/viscera of native (Goodea atripinnis), introduced (Poeciliopsis gracilis), and commercially important (Oreochromis niloticus) fish in Santa Catarina, an anthropized reservoir in Central Mexico. Additionally, we calculated the potential risk of human exposure due to the consumption of the studied species. The Santa Catarina Reservoir showed some physical and chemical water parameters generally associated with cyanobacterial blooms (e.g., high phycocyanin, chlorophyll-a, dissolved phosphorus concentrations, and alkaline pH) with presence of cyanotoxins produced by the cyanobacteria genera Microcystis, Dolichospermum, and Planktothrix, which were found in dissolved and particulate (sestonic) fractions of water. Moreover, we detected the presence of saxitoxins and microcystins in the tissues of all species studied. The risk of intoxication for humans was lower for the consumption of Nile tilapia muscle than for the other analyzed species, whose consumption should be avoided since it exceeds the recommended daily intake of microcystins for a short-term (i.e., two-week exposure time). These findings are remarkable because commercial fishing in reservoirs and the consumption of these fish could represent a route to human exposure to toxins, particularly microcystins. Our results highlight the need for the detection of cyanotoxins and the evaluation of their bioaccumulation by fish in unstudied eutrophic waterbodies, to reduce the potential health risk for humans and the environment.

Impact of thermal soil treatment on heavy metal mobility in the context of waste management.

Thermal soil treatment is a well-established remediation method to remove organic contaminants from soils in waste management. The co-contamination with heavy metals raises the question if thermal soil treatment affects heavy metal mobility in soils. In this study, four contaminated soils and a reference sample were subjected to thermal treatment at 105°C, 300°C and 500°C for 7 day. Thermogravimetry and differential scanning calorimetry were used to understand the reactions, and resulting gases were identified by Fourier-transformed infrared spectroscopy. Treated and untreated samples were characterised by X-ray diffraction (XRD) and electron microprobe analysis and subjected to pH-dependent leaching tests, untreated samples additionally by X-ray-fluorescence (XRF) and inductively coupled plasma mass spectroscopy (ICP-MS). Leachates were analysed using ICP-MS and ion chromatography. Maximum available concentrations were used for hydrogeochemical modelling using LeachXS/Orchestra to predict leaching control mechanisms. Leaching experiments show that thermal treatment tends to decrease the mobility at alkaline pH of Pb, Zn, Cd, As and Cu, but to increase the mobility of Cr. In the acidic to neutral pH range, no clear trend is visible. Hydrogeochemical modelling suggests that adsorption processes play a key role in controlling leaching. It is suggested that the formation of minerals with a more negatively charged surface during thermal treatment are one reason why cations such as Pb2+, Zn2+, Cd2+ and Cu2+ are less mobile after treatment. Future research should focus on a more comprehensive mineralogical investigation of a larger number of samples, using higher resolution techniques such as nanoscale secondary ion mass spectrometry to identify surface phases formed during thermal treatment and/or leaching.

Lignin degradation by a novel thermophilic and alkaline yellow laccase from Chitinophaga sp.

The characterization of the novel yellow laccase, Lac_CB10, derived from Chitinophaga sp. CB10, represents a significant advancement with broad implications. This enzyme displays exceptional stability and functionality under extreme conditions, operating effectively under both alkaline (pH 10.5) and thermophilic (80-90°C) environments. Its capability to maintain considerable activity over extended periods, even at high temperatures, showcases its potential for various industrial applications. Moreover, its distinctive ability to efficiently degrade lignin-demonstrated by a significant 52.27% degradation within 32 h-signifies a promising avenue for biorefinery processes. This newfound laccase's characteristics position it as a crucial asset in the realm of bioremediation, particularly in scenarios involving contamination at extreme pH and temperature levels. The study's findings highlight the enzyme's capacity to address challenges in industrial processes and environmental cleanup, signifying its vital role in advancing biotechnological solutions.

L-cysteine-coated magnetite nanoparticles as a platform for enzymes immobilization: Amplifying biocatalytic activity of Candida antarctica Lipase A

This study presents the synthesis of magnetite nanoparticles coated with L-cysteine (Fe3O4@LC) and their subsequent utilization as a support matrix for the immobilization of Candida antarctica Lipase A (CALA). The immobilization process involved physical interactions and covalent bonding mediated by glutaraldehyde. Comprehensive characterization was conducted using techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometry (VSM), providing compelling evidence of a successful synthesis. Under optimized conditions, employing 1 mg of protein per gram of support, pH 7 in a 25 mM phosphate buffer, and a 5 h reaction at 25 °C, immobilization on glutaraldehyde-activated support achieved an impressive yield of 85.0 % ± 2.6, accompanied by a specific activity of 212.5 ± 1.3 U/g, outperforming the physical adsorption approach. Remarkably, the immobilized enzyme exhibited higher activity than the free enzyme at alkaline and acidic pH levels. Furthermore, thermal and pH inactivation studies revealed that the biocatalyst's half-life exceeded that of free CALA by more than 8 times at pH 10. These results underscore the potential of the Fe3O4@LC-GLU-CALA system as a robust biocatalytic matrix with promising applications in biodiesel production, ester synthesis, and pharmaceutical manufacturing.

Effect of Foxtail Millet Cultivars on Yield and Yield Attributes under Different Sowing Windows

The investigation conducted at the Agronomy Farm, College of Agriculture, Pune, during the Kharif season of 2022 focused on the "Effect of foxtail millet cultivars on yield and yield attributes under different sowing windows." The study employed a split-plot design with sixteen treatments and three replications, involving four sowing dates (26 MW, 28 MW, 30 MW, and 32 MW) and four foxtail millet varieties (SiA 3156, SiA 3085, Suryanandi, and Renadu). The soil, a clay loam with slightly alkaline pH, low nitrogen, medium phosphorus, and high potassium levels, received RDF 60:30:30 N: P2O5: K2O kg ha-1 at sowing. The investigation monitored various growth parameters, including plant height, number of tillers, number of functional leaves, and dry matter accumulation, at different growth stages. The study revealed that early sowing at 26 MW significantly influenced plant height, number of tillers, and dry matter production, favoring greater vegetative growth. The Renadu variety consistently exhibited superior performance in plant height, tiller count, and dry matter accumulation compared to other varieties. Days to 50% flowering and maturity were significantly affected by both sowing dates and varieties, with early-sown crops taking more days to reach these stages. Grain yield, straw yield, and harvest index were influenced by sowing dates and varieties, with the combination of the Renadu variety and 26 MW sowing exhibiting the highest grain yield and straw yield. Renadu also displayed a superior harvest index, emphasizing its suitability for optimal growth and yield. The study recommends sowing foxtail millet on 26 MW or 28 MW, particularly with the Renadu variety, for achieving maximum growth and yield during the Kharif season. The findings highlight the significance of considering both sowing windows and foxtail millet varieties to optimize production in the given agro-climatic conditions of Pune, Maharashtra.

The impact of continuous cultivation of Ganoderma lucidum on soil nutrients, enzyme activity, and fruiting body metabolites

To explore the impacts of continuous Ganoderma lucidum cultivation on soil physicochemical factors, soil enzyme activity, and the metabolome of Ganoderma lucidum fruiting bodies, this study conducted two consecutive years of cultivation on the same plot of land. Soil physicochemical factors and enzyme activity were assessed, alongside non-targeted metabolomic analysis of the Ganoderma lucidum fruiting bodies under continuous cultivation. The findings unveiled that in the surface soil layer (0–15 cm), there was a declining trend in organic matter, ammonium nitrogen, available phosphorus, available potassium, pH, polyphenol oxidase, peroxidase, alkaline phosphatase, and sucrase, whereas nitrate nitrogen, electrical conductivity (EC), and salt content exhibited an upward trend. Conversely, in the deeper soil layer (15–30 cm), organic matter, ammonium nitrogen, available potassium, alkaline phosphatase, and sucrase demonstrated a decreasing trend, while nitrate nitrogen, available phosphorus, pH, EC, salt content, polyphenol oxidase, and soil peroxidase showed an increasing trend. Metabolomic analysis of Ganoderma lucidum fruiting bodies distinguished 64 significantly different metabolites between the GCK and GT groups, with 39 components having markedly higher relative contents in GCK and 25 components having significantly lower relative contents in GCK compared to GT. Moreover, among these metabolites, there were more types with higher contents in the fruiting bodies harvested in the first year (GCK) compared to those harvested in the second year (GT), with pronounced differences. KEGG pathway analysis revealed that GCK exhibited more complex metabolic pathways compared to GT. The metabolites of Ganoderma lucidum fruiting bodies were predominantly influenced by soil physicochemical factors and soil enzyme activity. In the surface soil layer (0–15 cm), the metabolome was significantly affected by soil pH, soil organic matter, available phosphorus, and soil alkaline phosphatase, while in the deeper soil layer (15–30 cm), differences in the Ganoderma lucidum metabolome were more influenced by soil alkaline phosphatase, soil catalase, pH, nitrate nitrogen, and soil sucrase.

Production of cellulase enzymes by <i>Bacillus</i> sp and <i>Pseudomonas</i> sp isolated from anthill soil

Cellulase turns the most widespread biopolymer and biologically sustainable resource, 'cellulose,' into reducing sugar. The study aimed at producing cellulase enzymes by bacteria isolated from anthill soil. Cellulase-producing bacteria were isolated from anthill soil using Carboxymethyl cellulose (CMC) medium. The isolates were screened for cellulase production by cultural, morphological, biochemical and sugar fermentation tests. Optimization of the fermentation medium for maximum cellulase production was carried out by one factor at a time (OFAT). Data obtained were analysed with the analysis of variance (ANOVA) using SPSS 2007, version 16.0. The identified Pseudomonas sp, Staphylococcus sp, E. coli and Bacillus sp were isolated with highest potential of cellulase production. The culture conditions like pH, temperature, carbon sources and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40oC at pH 8.5 with maltose as carbon source and yeast extract as nitrogen source. The highest activity and stability of cellulase enzymes between neutral to alkaline pH and high temperature.

Solvatochromism and halochromism in nitro lophine derivatives: Photophysical study, computational calculations and applications as pH sensing material

Nitro Lophines were readily synthesized via multicomponent reaction of benzil, nitro benzaldehyde and ammonium acetate. All three nitro Lophines were isolated in good yields and were also characterized by various analytical and spectroscopic techniques. A distinctive solvatochromism was observed in case of ortho and para nitro containing Lophines in their absorbance spectra. In particular, naked eye solvatochromism was observed, in case of para nitro Lophine, in the form of yellow and red coloured solution in methanol and DMSO respectively. Halochromism studies revealed the hypsochromic shift under acidic pH while bathochromic shift under alkaline pH for both nitro Lophines. Again the para nitro Lophine demonstrated wonderful distinctive colour change under acidic and alkaline pH in both methanol and DMSO as solvents. The measurement of absorbance at different pH values was carried out and the data obtained were used for calculation of dissociation constants employing several graphical methods. Computational calculations were carried out using TD-DFT for UV–Vis absorption calculation while graph-convolutional neural network model was utilized for calculation of dissociation constants. Ultimately, a reusable naked eye pH detection paper could be developed using para nitro Lophine as a sole indicator.

Synthesis, Structure and Photocatalytic Performance of {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n and Its Derivatives

A polynuclear metal-organic framework, {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n (Htza=1H-tetrazole-1-acetic acid), was successfully synthesized and characterized, and its photocatalytic properties, along with those of its derivatives, were investigated. The crystal structure of the compound was determined to belong to the orthorhombic space group Pn ma, featuring a 3D framework comprising cage-like [Bi6(µ3-O)3(µ3-OH)5]7+ clusters. {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n demonstrated significant photocatalytic activity with UV light response within the pH range of 6.0–8.0 and a band gap energy of 3.32 eV. Under optimal conditions, a reduction in chemical oxygen demand (COD) and total organic carbon (TOC) (from 126.90 mg/L to 4.57 mg/L) clearly validated the efficient methyl orange degradation. The main active groups in the degradation process were h+, ·O2− and ·OH, and the catalyst demonstrated reusability for up to six cycles. Moreover, it was hydrolyzed to Bi2O2CO3 and BiOCl under alkaline (pH=9.0–11.0) and acidic (pH=1.0–5.0) conditions, respectively, thus serving as a valuable precursor. Notably, the Bi2O2CO3 and BiOCl derivatives exhibited higher catalytic activities than catalysts synthesized using alternative methods under the same experimental conditions. Therefore, within the pH range of 1.0–11.0, {[Bi6(tza)5(NO3)2(OH)5O3]·H2O}n, along with its in situ derivatives BiOCl and Bi2O2CO3, were highly efficient UV light-driven photocatalysts.

Synthesis of MIL-53(Fe) implanted carbon spheres derived from resorcinol-formaldehyde resins for fast adsorption of antibiotics: Enhanced adsorption and pH adaptability

This article prepared a series of MIL-53(Fe) implanted carbon spheres derived from resorcinol-formaldehyde resins for rapid adsorption of Ciprofloxacin (CIP) using a facile hydrothermal coupling calcination methodology. Results indicated that MIL53(Fe)@RF-800, which was calcined at 800 °C, demonstrated the highest CIP removal efficiency of up to 95% within 60 min in batch adsorption tests. Moreover, MIL53(Fe) @RF-800 could remove over 95.8% of CIP at an amount of 0.2 mg/L, while both Cl− and HCO3− had a negligible impact on the CIP adsorption. It is noteworthy that when there was NO3− or SO42− in the solution, the impact of CIP adsorption displayed an inhibitory trend overall. In addition, MIL53(Fe)@RF-800 exhibited a broad pH range adaptability (over 95% CIP removal efficiency at pH = 3.0-10.5), even under highly acidic (pH <3.0) or alkaline (pH >10.5) conditions, the adsorption capacity for CIP was greater than 85%. In conclusion, this study provides novel insights into the development of highly porous MIL-53(Fe)-based adsorbent for rapid and pH-unrestricted adsorption of antibiotics and offers the possibility of practical engineering applications.

Adsorption Isotherms and Kinetic Studies for the defluoridation from Aqueous Solution Using Eco-friendly Natural Adsorbent like Terminalia Chebula

A practical technique for removing fluoride from aqueous solutions by adsorption was created using the natural adsorbent known as Terminalia Chebula with a primary emphasis on adsorption isotherms and kinetic studies. The experimental results showed the best conditions for removing fluorine ions as follows: the dosage of the natural adsorbent: 50 mg / L, contact reaction time: 40 mins, shaking speed = 120 rpm, temperature = 32 o C. The amount of removal of fluorine ions was found to be > 98% fluoride within a shorter time and reached adsorption equilibrium within 40 minutes with a maximum defluoridation capacity of 20.92 mg / g. At lower solution pH (3 to 5), there is higher fluoride adsorption on the adsorbent surface and as the pH becomes alkaline (pH > 7) the adsorption capacity decreased. The two co-ions namely NO3− and Cl− removed the fluoride 79% whereas, the phosphate ions did not have any marked effect on the defluoridation. The pseudo-second-order kinetic order such Langmuir, Empirical Freundlich, Temkin and Dubinin-Radushkevich isotherms can well predict the adsorption equilibrium rate to be at 0.044 mg / L with contact time (t) of 30 mins. In addition to that the adsorption is characterized by SEM, X-ray diffraction and FTIR techniques. This study has ultimately found that the Terminalia Chebula is a workable, natural material for fluoride elimination.

Isolation and screening of stress tolerant and plant growth promoting root nodulating rhizobial bacteria from some wild legumes of Nagaland, India

Wild legumes are widely distributed and better adapted to extreme agro-climatic conditions because of their soil microbiota. In the present study, Root Nodulating Bacteria (RNB) were isolated from wild legumes and analysed for their abiotic stress tolerant and Plant Growth Promoting Traits (PGPT). Rhizobial strains were identified based on their 16S rRNA sequences. A total of 14 rhizobial species were characterized based, of which six were Rhizobium (AIS3, AIS9, AIR14, LUMCR3, LUMVRW4, LUMVRW8), four belongs to Burkholderia (AIS12, MOLKCS15, CHMP9, CHMP10) and one each of genera Cupriavidus (LUMMD12), Herbaspirillum (LUMVRW4), Paraburkholderia (CHMP1) and Ralstonia (LUMDes9). Stress tolerance analysis found most of the strains are to be tolerant to alkaline pH (9–11) where highest tolerance exhibited by Rhizobium sp. (strain AIS9) and Burkholderia territorii (strain MOKCS15). Seven Rhizobial strains were able to thrive at lower temperature stress (10 and 20 °C); while, strains AIS9, CHMP1 and LUMMD21 were able to grow at higher temperature (40 and 50 °C). Most of the isolate could tolerate salinity stress up to 1.5 %; but, only isolates AIS9, AIS12 and LUMMD12 could tolerate 2 and 2.5 % salt concentrations. The PGPT analyses found LUMCR3 having the highest IAA production potentiality (102.5 µg/ml); while, isolate MOKCS15 exhibited highest phosphate solubilizing activity (4.1 Phosphate Solubilization Index). The RNB isolates in the present study exhibited both stress tolerance and PGP traits indicating their potential use as biofertilizer under extreme agronomic conditions to improve productivity.

Acute toxicity of petroleum asphalt seal coat leachates to Ceriodaphnia dubia is linked to polymer preservatives

Low-VOC waterborne asphalt-emulsion (AE) seal coat is considered more sustainable than solvent-based coal-tar emulsion seal coat because asphalt emulsions contain negligible amounts of carcinogenic PAHs and release fewer harmful volatile organic compounds. Yet, many low-VOC coatings leach water-soluble substances under outdoor conditions. To investigate the chemical composition of seal coat leachates, three AE formulations were cured under natural weathering conditions and exposed to simulated runoff over a 10-day field trial. Runoff was collected and concentrated using ion-exchange solid-phase extraction (SPE) and analyzed using gas chromatography/mass spectrometry (GC–MS). Leached compounds included hydrocarbons, esters, amines, siloxanes, plasticizers, biocides, polyethylene glycol (PEG) ethers, urethanes, and toluene diisocyanate (TDI). Glycol ethers comprised 29–97 % of the measured leachate mass. Two seal coat formulations contained isothiazolinone biocides, methylchloro- and methylisothiazolinone (CMIT/MIT; 0.5 mg/L in runoff), while a third seal coat formulation continuously leached TDI, a reactive polyurethane (PU) precursor (0.7 mg/L in runoff). Biocide-containing leachates showed acute toxicity to the freshwater water flea, Ceriodaphnia dubia after 48 h, while TDI-containing leachate showed no acute toxicity, suggesting that leachate toxicity was due to in-can polymer preservatives. As biocides are implicated in impaired reproductive signaling, these results support the use of alkaline pH to avoid biofouling and reinforce the goal of reducing and/or avoiding the use of biocides altogether, especially for environmentally friendly products.

Comparative evaluation of conventional and ultrasound assisted tube cystotomy for obstructive urolithiasis in cattle

The aim of this study was to evaluate the efficacy of conventional and ultrasound assisted tube cystotomy techniques for obstructive urolithiasis in 12 cattle by allowing two groups. Group-I, animals were subjected to conventional tube cystotomy, whereas in group- II, ultrasound assisted tube cystotomy was performed using Foley’s catheter under deep sedation with xylazine hydrochloride and local infiltration anaesthesia. Clinically, all animals showed urethral pulsation, dribbling of urine, futile attempts, bellowing, congested mucous membrane, sunken eyes, dry muzzle and teeth grinding. Non-significant changes were observed in haematological and biochemical values, however neutrophilia and alkaline pH of urine was prominent. Ultrasound assisted tube cystotomy technique consumed less time (40.00±1.29 min) with small incision and minimal bleeding as compared to conventional tube cystotomy.

Utilization of Multi-Ionic Interaction of Yumoto Hot Springs for Enhancing the Moisturizing Properties of Hyaluronic Acid Sodium Salt

Hot spring (HS) waters manifest diverse positive effects on the skin due to their unique chemical compositions. Sodium hyaluronate acid (HA) comprises N-acetylglucosamine and D-glucuronic acid, and distinguishes itself with superior qualities in skin regeneration, providing moisturizing and anti-aging benefits. The combination of HA with HS water is widely applied across ophthalmology, pneumology, nutrition, and cosmetics. This study delved into the application of HA in cosmetology, with a focus on its interaction with HS water and its effects on moisture retention and promoting wound healing. In particular, with the alkaline pH levels of the Yumoto HS, HA molecules may undergo dissociation to be ionized resulting in a negatively charged polymer and interacting with positively charged ions in the HS water through electrostatic interactions. The shifted peaks in the FTIR result and zeta potential shifts to a less negative region in the case of HA-HS compared to HA-DI indicate an ionic interaction between HS water and HA. Moisture tests confirmed the sustained hydration when HA is dissolved in HS water, underscoring its potential to improve skin hydration at certain concentrations, specifically at 0.5% and 1%. Additionally, MTT assay results demonstrated that HS water stimulates the growth of fibroblast cells compared to distilled water, implying its potential beneficial effect in wound healing. These findings suggested the multifaceted benefits of HAHS in skincare, highlighting its role in enhancing skin hydration and potentially accelerating wound healing processes, thus presenting avenues for the development of advanced cosmeceutical formulations.

Optimization of seeding rates and nitrogen scheduling in direct-seeded rice (Oryza sativa) under drought-prone environment in middle Indo-Gangetic plains

A field experiment was conducted during the rainy (kharif) seasons of 2014 and 2015 at Patna, Bihar to optimise the seeding rates and nitrogen scheduling for direct-seeded rice (Oryza sativa L.) under the rainfed drought-prone environment. The soil of the experimental plot was loamy, low in organic carbon (0.42) and available N (149.6 kg/ha), high in available phosphorus (25.8 kg/ha), medium in available potash content (183.6 kg/ha) and slightly alkaline (pH 7.7). The treatments consisted of 3 seeding rates (S1: 20 kg/ha; S2 : 30 kg/ha; and S3 : 40 kg/ha) in main-plot and four nitrogen schedules (N1 , 1/3 N as basal and 2/3 N at maximum tillering; N2 , 1/3 N as basal and 1/3 N at maximum tillering and 1/3 N at panicle initiation; N3 , 1/2 N at first shower/enough moisture availability preferably after first weeding and 1/2 N at maximum tillering; and N4 , 1/3 N at first shower/enough moisture availability preferably after first weeding, 1/3 N at maximum tillering and 1/3 N at panicle initiation stage) in sub-plot and replicated thrice in split-plot design. The results revealed that the grain yield was significantly higher with S3 (3.2 t/ha) than that to S1 (2.4 t/ha), but statistically at par with that obtained with S2 (3.1 t/ha). Varying nitrogen schedules did not affect the grain yield markedly. Comparatively higher grain yield was recorded with N4 (3.0 t/ha) followed by N3 (2.94 t/ha) and N1 (2.87 t/ha). The gross returns (32.1 ×103 /ha), net returns (15.9 × 103 /ha) and benefit: cost ratio (1.64) were significantly higher with 40 kg/ha seed rate compared to 20 kg/ha ( 22.4 ×103/ha, 6.2 ×103/ha and 1.26 but statistically similar to 30 kg/ha ( 28.9 ×103 /ha, 13.4 ×103/ha and 1.55. The net returns were significantly higher with N4 closely followed by N3. Hence, growing of direct-seeded rice using 40 kg/ha seed rate along with split application of 1/3rd N at first shower/enough moisture availability preferably after first weeding, 1/3rd N at maximum tillering and 1/3rd N at panicle initiation stage is an ideal and sustainable approach in terms of productivity and profitability under rainfed drought-prone environment of Eastern India.

Natural pigments and antioxidants properties of annatto extract at various pH of distilled water solvent and extraction times

Annatto is a natural colouring agent obtained from the outer coats of the seeds of the Bixa orellana. Carotenoid pigment in annatto consists of bixin and norbixin. Pigment extraction from annatto seeds is commonly done by indirect extraction using organic solvents and direct extraction using oil or aqueous alkali. This research aims to characterize the natural pigment and antioxidants of annatto extract. The annatto was extracted by maceration using distilled water at various pH and extraction times. The distilled water pH variations used in this study were 4, 7, and 9 while the extraction times were 5, 7.5 and 10 mins. Analyzing bixin and norbixin revealed the potential of annatto extract as a natural pigment, while phenol and flavonoids disclose the potential as a natural antioxidant. The results showed that varying pH of distilled water and time of extraction influences the bixin, norbixin, total phenol, and flavonoid contents of annatto extract. Annatto extraction using distilled water produces higher levels of bixin than norbixin. The highest levels of bixin (61.06%) were built in distilled water pH 7 for 7.5 mins of extraction, while the highest levels of norbixin (30%) were produced in distilled water pH 7 for 10 mins. Extraction using pH 4 creates a higher level of total phenol while increasing the extraction time up to 10 mins decreased the total phenol content. However, high levels of flavonoids were made in extraction using alkaline pH distilled water (pH 9) for 10 mins. The results showed that all extracts have the potential as natural pigments and antioxidants.

Exploring the rheological and thermal behavior of cowpea protein concentrate: Impact of pH and concentration

This study confronts challenges from global population growth, focusing on protein supply strains and the environmental impact of traditional animal sources. Delving into unexplored territory, this study investigates the combined effects of pH, concentration, and temperature on the rheological and thermal properties of cowpea protein concentrate (CPC). Steady-state and oscillatory rheological tests, along with differential scanning calorimetric analysis, were conducted to unveil the behavior of CPC solutions. The results revealed sensitivity to protein concentration and shear rate, especially at higher concentrations (>10%), and pH emerged as a critical factor, significantly influencing shear stress and viscosity. The elastic and viscous components of alkaline CPC solutions exhibit weak gel behavior, influenced by both pH and frequency. Temperature-induced changes in viscosity and gelation highlight the interaction between thermal conditions and protein structures. The thermal cycle helps explain changes in molecular interactions induced by temperature, with pH playing a role in influencing gelatinization and denaturation. The denaturation temperature (Td) in the thermograms corresponds to vicilin fractions and emphasizes the prominence of denaturation and gelation at neutral pH, where Td was pH 7 > pH 9 > pH 11. Alkaline pH induced significant structural changes, resulting in a gelation onset temperature below the denaturation onset temperature. This study provides a deeper understanding into the rheological and thermal properties of CPC solutions, emphasizing the roles of concentration, pH, and temperature, useful for various steps of industrial processing, before and after thermal gelation. These findings are important for promoting the use of cowpea proteins in the food industry in response to the evolving needs of a growing global population.

The Role of Microbial Diversity in Lignocellulosic Biomass Degradation: A Biotechnological Perspective

AbstractLignocellulosic biomass, such as plant residues and agricultural waste, holds immense potential as a renewable resource for the production of biofuels, chemicals, and animal feed. However, the efficient degradation of lignocellulose into fermentable sugars remains a significant challenge. Recent research has highlighted the critical role of microbial diversity in lignocellulosic biomass degradation, offering new insights from a biotechnological perspective. The comprehension and utilization of microbial diversity are crucial for developing efficient biotechnological strategies for lignocellulosic biomass degradation. By uncovering the intricate relationships between microbial communities and their enzymatic machinery, researchers can optimize degradation processes, enhance biofuel production, and contribute to a more sustainable bio‐based economy. Microorganisms, including bacteria, fungi, and archaea, possess diverse enzymatic capabilities, allowing them to secrete a plethora of lignocellulolytic enzymes. Microbial organisms inhabiting extreme environments, such as the rumen, hot and cold springs, deep sea trenches, and acidic and alkaline pH environments, exhibit significant potential in generating enzymes, including hemicellulolytic and lignocellulolytic enzymes, which possess superior biochemical properties essential for industrial bioconversion applications. This review explores the ability of lignocellulosic enzymes from microbial sources to efficiently break down the lignocellulosic biomass and their potential applications in industrial biotechnology.

Characterization of Geochemical and Isotopic Profiles in the Southern Zone Geothermal Systems of Mount Seulawah Agam, Aceh Province, Indonesia

The Seulawah Agam geothermal area exhibits significant potential as a source of energy for power generation, with an estimated capacity of 130 MW. Geological and geochemical investigations indicate that the Seulawah Agam geothermal system is part of the extensive Sumatra Fault. Analysis of the geochemical composition of geothermal water at the South Zone manifestation location of Mount Seulawah Agam, Aceh Province-Indonesia, involves examining cation (K+, Na+, Ca2+, and Mg2+), anion (Cl-, HCO3-, and SO42-), and isotope (δD and δ18O) contents. This data aids in estimating reservoir temperatures using geothermometer equations. Surface characteristics of the South Zone manifestation reveal neutral to alkaline pH values (6.02 to 8.68), relative temperatures (29.97 to 42.57 ºC), conductivity (49.8 to 100.7 mV), and TDS (Total Dissolved Solids) ranging from 352.6 to 497.0 mg/L. The dominant water composition is sodium–calcium–bicarbonate (Ca–Na–HCO3), indicating a bicarbonate water type. Average temperature depths in the South Zone manifestation of Mount Seulawah Agam are estimated as follows: Alue Ie Seu’um around 288.84 ± 2.19 ºC, Alue Ie Masam around 304.17 ± 20.9 ºC, Alue PU around 290.02 ± 6.85ºC, and Alue Teungku around 265±11.39 ºC. Isotope data (δD and δ18O) suggest meteoric water as the source for this manifestation. Fluid geochemical analysis indicates the potential for utilizing the geothermal manifestations of the South Zone of Mount Seulawah Agam for geothermal development or the construction of a geothermal power plant, given its high enthalpy system with an average temperature exceeding 225 ºC. Further research, including data drilling, is essential to gather precise subsurface data. Additionally, the Aceh Provincial Government should formulate policies to identify strategic areas for geothermal development, leveraging the existing exploitable potential.