Acid Yield Research Articles

Streptomyces fradiae Mitigates the Impact of Potato Virus Y by Inducing Systemic Resistance in Two Egyptian Potato (Solanum tuberosum L.) Cultivars

In this study, the impact of culture media filtrate of QD3 actinobacterial isolate on two potato cultivars, Spunta and Diamond, infected with potato virus Y (PVY) was investigated. Various parameters, including infection percentage, PVY virus infectivity, disease severity scoring, PVY optical density, photosynthetic and defense-related biochemical markers, enzymatic profiling, phenolic compounds, proline content, salicylic acid levels, and growth and yield parameters, were assessed to elucidate the potential of the QD3 actinobacterial isolate culture filtrate in mitigating PVY-induced damage. The physiological and biochemical characteristics of the QD3 actinobacterial isolate, including its salinity tolerance, pH preferences, and metabolic traits, were investigated. Molecular identification via 16S rRNA gene sequencing confirmed its classification as Streptomyces fradiae QD3, and it was deposited in GenBank with the gene accession number MN160630. Distinct responses between Spunta and Diamond cultivars, with Spunta displaying greater resistance to PVY infection. Notably, pre-infection foliar application of the QD3 filtrate significantly reduced disease symptoms and virus infection in both cultivars. For post-PVY infection, the QD3 filtrate effectively mitigated disease severity and the PVY optical density. Furthermore, the QD3 filtrate positively influenced photosynthetic pigments, enzymatic antioxidant activities, and key biochemical components associated with plant defense mechanisms. Gas chromatography‒mass spectrometry (GC‒MS) analysis revealed palmitic acid (hexadecanoic acid, methyl ester) and oleic acid (9-octadecanoic acid, methyl ester) as the most prominent compounds, with retention times of 23.23 min and 26.41 min, representing 53.27% and 23.25%, respectively, of the total peak area as primary unsaturated fatty acids and demonstrating antiviral effects against plant viruses. Cytotoxicity assays on normal human skin fibroblasts (HSFs) revealed the safety of QD3 metabolites, with low discernible toxicity at high concentrations, reinforcing their potential as safe and effective interventions. The phytotoxicity results indicate that all the seeds presented high germination rates of approximately 95–98%, suggesting that the treatment conditions had no phytotoxic effect on the Brassica oleracea (broccoli) seeds, Lactuca sativa (lettuce) seeds, and Eruca sativa (arugula or rocket) seeds. Overall, the results of this study suggest that the S. fradiae filtrate has promising anti-PVY properties, influencing various physiological, biochemical, and molecular aspects in potato cultivars. These findings provide valuable insights into potential strategies for managing PVY infections in potato crops, emphasizing the importance of Streptomyces-derived interventions in enhancing plant health and crop protection.

Enhancing acid resistance of Escherichia coli based on directed morphology evolutionary of key transcription factor bolA

Succinic acid, as one of the important fermentation products, is commonly used as an acidulant, flavoring agent, and antimicrobial agent. However, the accumulation of organic acids in the later fermentation phase will restrict the production efficiency of strain. To address this issue, the directed evolution on the key transcription morphology factor bolA gene was performed to enhance acid resistance of Escherichia coli by ep-PCR library and CRISPR/Cas9. The best mutant strain 5-21-5 was screened from 4000 mutant colonies ep-PCR library, which showed higher cell survives in succinic acid stress. Its acid resistance ability was systematically illustrated from multiple aspects by transmission electron microscope (TEM), confocal laser scanning microscopy (CLSM), and three-dimensional excitation emission matrix (3D-EEM) analysis, respectively. Higher tyrosine and tryptophan protein level was beneficial to acid resistance, while cell tend to short rod shape. Subsequently, with the assistance of the CRISPR/Cas9 gene editing technology knocking the mutated sequences into the genome, the succinic acid yield of strain M-K10 reached 9.8 g/L, representing a 15.29% increase compared to the Escherichia coli MG1655 without gene editing.

Comparative evaluation of the extracellular production of a polyethylene terephthalate degrading cutinase by Corynebacterium glutamicum and leaky Escherichia coli in batch and fed-batch processes

BackgroundWith a growing global population, the generation of plastic waste and the depletion of fossil resources are major concerns that need to be addressed by developing sustainable and efficient plastic recycling methods. Biocatalytic recycling is emerging as a promising ecological alternative to conventional processes, particularly in the recycling of polyethylene terephthalate (PET). However, cost-effective production of the involved biocatalyst is essential for the transition of enzymatic PET recycling to a widely used industrial technology. Extracellular enzyme production using established organisms such as Escherichia coli or Corynebacterium glutamicum offers a promising way to reduce downstream processing costs.ResultsIn this study, we compared extracellular recombinant protein production by classical secretion in C. glutamicum and by membrane leakage in E. coli. A superior extracellular release of the cutinase ICCGDAQI was observed with E. coli in batch and fed-batch processes on a litre-scale. This phenomenon in E. coli, in the absence of a signal peptide, might be associated with membrane-destabilizing catalytic properties of the expressed cutinase. Optimisations regarding induction, expression temperature and duration as well as carbon source significantly enhanced extracellular cutinase activity. In particular, in fed-batch cultivation of E. coli at 30 °C with lactose as carbon source and inducer, a remarkable extracellular activity (137 U mL−1) and cutinase titre (660 mg L−1) were achieved after 48 h. Literature values obtained with other secretory organisms, such as Bacillus subtilis or Komagataella phaffii were clearly outperformed. The extracellular ICCGDAQI produced showed high efficacy in the hydrolysis of PET textile fibres, either chromatographically purified or unpurified as culture supernatant. In less than 18 h, 10 g L−1 substrate was hydrolysed using supernatant containing 3 mg cutinase ICCGDAQI at 70 °C, pH 9 with terephthalic acid yields of up to 97.8%.ConclusionExtracellular production can reduce the cost of recombinant proteins by simplifying downstream processing. In the case of the PET-hydrolysing cutinase ICCGDAQI, it was even possible to avoid chromatographic purification and still achieve efficient PET hydrolysis. With such production approaches and their further optimisation, enzymatic recycling of PET can contribute to a more efficient and environmentally friendly solution to the industrial recycling of plastics in the future.

Effects of Two Different Size ZnO Nanoparticles on the Growth of Aspergillus oryzae

Two different kinds of ZnO nanoparticles (NPs) with distinct particle sizes were synthesized by a precipitation method. For the first time, the effects of two distinct sizes ZnO NPs on the growth, photoluminescence properties and kojic acid (KA) yield of Aspergillus oryzae (A. oryzae) were examined. The findings showed that ZnO-A and -B NPs, with average particle sizes of 11.93 nm and 34.41[Formula: see text]nm, respectively, exhibited a hexagonal crystal structure. It was found that when the concentration of NPs was below 100[Formula: see text][Formula: see text]g/mL, ZnO NPs were nontoxic and served as activators to stimulate the growth of A. oryzae, and the biomass of solid and liquid medium, the total integral emission intensity, the content of extracellular protein and total organic carbon and KA yield of A. oryzae grown with ZnO-A (ZnO-B) NPs were about 2.19 (1.97), 2.47 (1.56), 1.67 (1.16), 2.45 (1.95), 0.47 (0.50) and 2.07 (1.37) times more than that of control sample (without NPs), respectively.

Conversion of Cellobiose to Formic Acid as a Biomass-Derived Renewable Hydrogen Source Using Solid Base Catalysts.

Formic acid is considered a promising hydrogen carrier. Biomass-derived formic acid can be obtained by oxidative decomposition of sugars. This study explored the production of formic acid from cellobiose, a disaccharide consisting of d-glucose linked by β-glycosidic bonds using heterogeneous catalysts under mild reaction conditions. The use of alkaline earth metal oxide solid base catalysts like CaO and MgO in the presence of hydrogen peroxide could afford formic acid from cellobiose at 343 K. While CaO gave 14 % yield of formic acid, the oxide itself was converted to a harmful metal peroxide, CaO2 after the reaction. In contrast, MgO could produce formic acid without the formation of the metal peroxide. The difficulty in selectively synthesizing formic acid from cellobiose using these solid base catalysts was due to the poor conversion of cellobiose to glucose. Using a combination of solid acid and base catalysts, a high formic acid yield of 33 % was obtained under mild reaction conditions due to the quantitative hydrolysis of cellobiose to glucose by a solid acid followed by the selective decomposition of glucose to formic acid by a solid base.

Exploring the integrated potential of pyrolysis and low-temperature wet torrefaction for typical medical waste valorization: A multifaceted approach leveraging online TG-FTIR-MS, 2D-COS, iso-conversional kinetics, and reaction mechanisms

The rapid growth of medical waste, exacerbated by the COVID-19 pandemic and advancements in healthcare, has drawn increased public scrutiny regarding its proper disposal and treatment. This research aimed to characterize the wet torrefaction of a typical medical waste biomass (MWB) composition, comprising bamboo swabs, skewers, splints, cotton balls, tongue depressors, toothpicks, and chopsticks, followed by its co-pyrolysis with medical waste plastic (MWP) including catheter bags, drapes, IV tubing, IV bags, oxygen masks, syringes, and test tubes. The study employed thermogravimetric analysis, TG-FTIR, 2D correlation spectroscopy, iso-conversional kinetics, and mass spectrometry techniques elucidated the driving factors, behaviors, products, mechanisms, and pathways involved. The pyrolysis temperature ranges were 180.15 to 400 °C for TMWB and 380.04 to 550 °C for MWP, with average activation energies of 150.22 and 221.59 kJ/mol for their respective devolatilization processes. Incorporating 20 % and 40 % MWP into the co-pyrolysis process yielded the best performance, characterized by the lowest activation energy. The co-pyrolysis process promoted the release of cyclic hydrocarbons and chain hydrocarbons, but decreased the yields of alcohols, esters, ethers, phenols, and acids, through synergistic mechanisms. Unraveling the pyrolysis pathways and dynamics of these representative medical waste streams offers valuable insights into improving energy recovery, mitigating pollution, diminishing waste volumes, and optimizing industrial thermochemical conversion processes for safely treating these hazardous materials.

Research on Engineering the Saccharomyces uvarum for Constructing a High Efficiency to Degrade Malic Acid and Low Yield of Diacetyl Biosynthesis Pathway.

Diacetyl is a flavor compound in wine with a low threshold (1-2 mg/L). It is produced during alcoholic fermentation (AF) Saccharomyces and malolactic fermentation (MLF) initiated by lactic acid bacteria (LAB). Whereas, the environment after AF suppresses the normal metabolism of LAB after AF. Researchs have shown the influence on diacetyl mechanisms of the genes ILV2, ILV6, ILV3, ILV5, BDH1, BDH2, and gene aldB from Lactobacillus plantarum in Saccharomyce uvarum WY1. While we found that the diacetyl contents produced by mutants after MLF (Co-fermentation and Seq-fermentation) were significantly improved compared to AF alone. Moreover, the genes mae1 and mae2 from S. pombe, and gene mleS from L. lactis exhibited significant effect on deacidification in our previous study, but the diacetyl of the mutants showed obvious improvement in this study. Thus the effects of association mutation of genes (ILV2, ILV6, ILV3, ILV5, BDH1, BDH2, aldB, mae1, and mleS) on deacidification, diacetyl and other flavors (organic acids, higher alcohols and esters) metabolism in S. uvarum after AF were detected in the study. Among all the mutants, strains V6AmS, V635mS, and V6B12mS showed the most favorable results. Specifically, the L-malic acid contents decreased to 1.26 g/L, 1.18 g/L, and 1.19 g/L, respectively. Concurrently, diacetyl levels were reduced by 52.56%, 61.84%, and 65.31%. The production of n-propanol increased by 18.84%, 20.89%, and 28.12%, whereas isobutanol levels decreased by 37.01%, 42.36%, and 44.04%, and isoamyl alcohol levels decreased by 19.28%, 19.79%, and 16.74%, compared to the parental strain WY1. Additionally, the concentration of lactate ester in the wine increased to 13.162 mg/L, 14.729 mg/L, and 14.236 mg/L, respectively.

Metabolic engineering of hairy root cultures in Beta vulgaris for enhanced production of vanillin, 4-hydroxybenzoic acid, and vanillyl alcohol.

The flavor of vanilla is a complex blend of compounds, with vanillin as the most prominent, along with vanillyl alcohol and 4-hydroxybenzoic acid. Natural vanillin extracted from vanilla beans is expensive, so researchers use heterologous synthesis to produce nature-identical vanillin in plant hosts. Consequently, alternative traditional farming and gathering methods are required to bridge the significant disparity between supply and demand. The current research successfully developed a method to induce hairy root formation from leaves. It integrated the Vanillin synthase (VpVAN) gene into transgenic hairy root lines of Beta vulgaris, synthesizing vanillin-related compounds. The presence of the VpVAN gene in transgenic roots was confirmed using PCR analysis. Additionally, RT-qPCR analysis demonstrated the expression of the VpVAN gene in the transgenic root lines. The transgenic hairy root clones H1, H2, and H5 showed enhanced vanillin production, vanillyl alcohol, and 4-hydroxybenzoic acid. Elicitation with methyl jasmonate (MJ) and salicylic acid (SA) further improved the production of these compounds in B. vulgaris hairy roots. The maximum hairy root biomass was observed after 60 days, with the maximum synthesis of vanillin and 4-hydroxybenzoic acid obtained from hairy root clones H5 and HR2, respectively. Vanillyl alcohol HR2 was obtained on the 45th day of cultivation. Elicitation with wound-associated hormone methyl jasmonate and salicylic acid enhanced the yield of vanillin, vanillyl alcohol, and 4-hydroxybenzoic acid, with a 215-fold increase in vanillin, a 13-fold increase in vanillyl alcohol, and a 21 fold increase in 4-hydroxybenzoic acid. The study results indicate that establishing transgenic hairy root cultures with the VpVAN gene is a promising alternative method for enhancing the production of vanilla flavor compounds such as vanillin, vanillyl alcohol, and 4-hydroxybenzoic acid. A cost-effective protocol has been developed to mass-produce phenolic compounds using a hairy root culture of B. vulgaris. This approach addresses the increasing demand for these substances while reducing the cost of natural vanillin production, making it suitable for industrial-scale applications.

B-184 Purifying High-Quality Genomic DNA From Frozen Blood Samples Stored up to 1.5 Years at -20°C

Abstract Background Maintaining DNA integrity in blood samples, from transport to storage to processing, is crucial to the success of downstream applications, especially regarding diagnostic applications. Additionally, due to the invasive nature of collecting blood samples, minimizing resampling to avoid excess patient pain and cost of collection and transportation are important to consider. Having the option to store and maintain portions of blood samples in the freezer enables future retesting without recollection. Since -20°C freezers generally are more affordable, require less energy, and have smaller footprints than -80°C freezers, demonstrating frozen blood stability at -20°C temperatures could decrease sampling burdens for labs with facility constraints. Methods Whole blood was collected into 9mL vacuum tubes (HemaSure-OMXP) from healthy donors. Aliquots of whole blood and buffy coat samples were stored at -20°C and thawed for genomic DNA extractions (QIAamp DNA Blood Mini Kit, Qiagen) at a range of different timepoints; frozen whole blood samples were processed at 0, 49, 141, and 148 days and frozen buffy coat samples were processed at 7, 27, 36, 185, 246, 373, 394, 584, and 604 days. Purified gDNA was quantified with Qubit (Broad Range dsDNA Assay, ThermoFisher) and qualified with Nanodrop One Microvolume UV-Vis Spectrophotometer (ThermoFisher) and TapeStation (Genomic DNA ScreenTape, Agilent Technologies). Results No significant decrease was observed for DNA yield and quality between fresh and frozen whole blood samples. Average DNA yields from 200 μL whole blood were 4.5 ± 2.2 μg and 5.3 ± 1.2 μg for fresh and frozen blood respectively. Average DNA integrity (DIN) was 6.9 ± 0.4 and 7.1 ± 0.3 for fresh and frozen blood respectively. Donor differences in blood samples can help explain the variance in DNA yields reported. No significant decrease was observed for DNA yield and quality in buffy coat samples frozen for longer at -20°C. In total, 84 whole blood and 25 buffy coat samples were processed in this study. Conclusions Although buffy coat samples tended to have higher yields than whole blood, due to the higher amount of white blood cells present, both sample types provided sufficient amounts of gDNA for downstream applications. Freezing blood samples for future testing can be effective at reducing the need for resampling without sacrificing the nucleic acid yield or quality of fresh samples. Additionally, as technological advancements are made for equipment and assays, frozen blood samples can be retested and compared to previous results for improved diagnostic decisions, done without requiring recollection from labs and patients.

Sustainable production of organic acids from chitin biomass catalyzed by Keggin-type heteropolyacid under hydrothermal condition

The “shell biorefinery,” which valorizes the shell waste chitin into fine chemicals, has developed rapidly in recent years. Herein, we present a novel base-free heteropolyacid-catalyzed oxidation method for the transformation of chitin biomass into organic acid. After a series of optimization experiments, a 5.93 % yield of formic acid and 25.09 % yield of acetic acid were achieved in the presence of 0.5 equivalent of Mo-V-P heteropolyacids (H4PMo11VO40·2H2O) and air at 180 °C under hydrothermal conditions for 4 h. Meanwhile, we have demonstrated that the Keggin-type heteropolyacid catalysts are capable of efficiently converting microcrystalline chitin into organic acids. The synthesized heteropolyacids are well characterized with FT-IR, XRD, ICP-AES, and TGA. The possible reaction pathway was speculated accordingly. This method offers several advantages, including readily available raw materials, simple operation, and relatively higher yield.

Heteropoly Acid‐Based Ionic Liquid Catalyzes Cellulose into Levulinic Acid in a Bi‐Phase Solvent System

AbstractLevulinic acid is an important chemical intermediate, which has many applications in organic synthesis, industry, agriculture, and medicine. In this word, three kinds of heteropoly acid based ionic liquids ([IMPS]H2PW12O40、[PyPS] H2PW12O40 [TEAPS] H2PW12O40) were used to catalyze the one‐pot conversion of cellulose to levulinic acid. [IMPS]H2PW12O40 has the highest catalytic activity due to its strong Hammett acidity (H0). In addition, the effect of biphasic solvent systems on the conversion of cellulose to levulinic acid was also studied. The results showed that the GVL/H2O system could effectively promote the conversion of cellulose and increase the yield of levulinic acid. The yield of levulinic acid could reach 52.6% and the conversion rate of cellulose was 91.2% at 180 °C for 180 min under the GVL/H2O volume ratio of 1:1 with [IMPS]H2PW12O40 as a catalyst at 1 Mpa N2 and cellulose as raw material. And [IMPS]H2PW12O40 can be recycled up to five times without significant performance loss. This study provides a promising method for efficiently converting cellulose and other biomass resources to levulinic acid extraction.

Harnessing synergistic metabolism: Bioelectricity and color removal from palm oil mill effluent in bacteria consortium – microalgae microbial fuel cell

This study investigated the application of a microbial fuel cell (MFC) system integrated with freshwater microalgae Chlorella sp. TSU-FF67for wastewater treatment, electricity generation, and bio-oil production. The MFC with Chlorella sp. TSU-FF67achieved a significantly higher open-circuit voltage (OCV) of 413.67 ± 15.67 mV compared to the control (13.33 ± 6.38 mV), indicating enhanced bioelectrocatalytic activity. The system also demonstrated efficient organic matter removal from palm oil mill effluent (POME) with a maximum color removal of 95.12 ± 3.50%. Furthermore, Chlorella sp. TSU-FF67 recovered from the PMFC exhibited a remarkable docosahexaenoic acid (DHA) yield of 1,932.28 ± 88.69 µg/mL (1.93 ± 0.08 mg/mL), highlighting its potential as a feedstock for bio-oil production. This work presents a promising approach for sustainable wastewater treatment while simultaneously generating bioelectricity and bio-oil using microalgae-MFC integration.

Boosting lactic acid photocatalytic synthesis from biomass sugars: The synergistic effect of N-doped carbon dots on ultrathin carbon nitride

The green and sustainable production of lactic acid via photocatalytic conversion of biomass-derived sugars is highly significant owing to its enhanced efficiency and reduced energy requirements. Consequently, the investigation has engineered a metal-free photocatalyst (NCDs/CCN), consisting of N-doped carbon dots (NCDs) and ultrathin carbon nitride (CCN). This catalyst has an enhanced light absorption range, facilitating a marked acceleration in the separation rate of photogenerated carriers. It has demonstrated the capability to achieve a lactic acid yield of up to 87.6 % in just 90 min with a mere 20 mg catalyst concentration in a xylose-alkali system. Electron Paramagnetic Resonance (EPR) and quenching experiments indicate that superoxide radicals (·O2−) are the primary oxidizing active species in the photocatalytic system, followed by h+, ·OH, and 1O2. DFT analysis suggests nitrogen doping enhances interaction with xylose, lowering adsorption energy and accelerating lactic acid generation, thus improving economic feasibility and sustainability.

Application of neural network in prediction of acetic acid yield by Acetobacters

In the present work, artificial neural network (ANN) is applied for the estimation of acetic acid yield for 3 different species of Acetobacters like, Acetobacter pasteurianus (NCIM 2104), Acetobacter aceti (NCIM 2116) and Acetobacter xylinum (NCIM 2526). Though there is open literature mentioning acetic acid and ANN can be found, they hardly describe the usage of ANN in prediction of fermentation based acetic acid production. Indeed, a deep dearth of existing literature is felt in this area to develop a robust ANN model to predict the yield of biologically obtained acetic acid and this work is a step towards bridging that research gap. The performance of the model has been estimated with R2 (0.992, 0.988 and 0.992, respectively for the mentioned microbial species) and RMSE (0.0287, 0.034 and 0.020, respectively for the same species). The most relevant operating parameters like, temperature, agitator speed, concentrations of supplemented yeast extract and tryptone, have been considered to carry out fermentation on cheese whey permeate containing fermentable lactose (48.5 g L-1) to transform into acetic acid. Outcome datasets obtained from rigorous experimental investigations performed on the direct fermentative production of acetic acid are trained in the ANN model to predict the product yield. Such machine-learning methodology encourages reasonably accurate prediction of product generation which is extremely tough to obtain through classical analytical processes.

From agricultural biomass to D form lactic acid in ton scale via strain engineering of Lactiplantibacillus pentosus

Worsening environmental conditions make lactic acid a sustainable alternative to petroleum-based plastics. This study created a genetically-engineered strain Lactiplantibacillus pentosus PeL containing a disrupted L-lactate dehydrogenase gene to produce high yield and optically pure D-lactic acid. Cellobiose was identified as the optimal sugar in the single carbon source test, yielding the highest lactic acid. In 5-L fermentation tests, pretreated wood chips hydrolysate was the best lignocellulosic substrate for PeL, resulting in a D-lactic acid yield of 900.7 ± 141.4 mg/g of consumed sugars with an optical purity of 99.8 ± 0.0 %. Gradually scaled-up fermentations using this substrate were achieved in 100-, and 9,000-L fermenters; PeL produced remarkably high D-lactic acid yields of 836.3 ± 11.9 and 915.9 ± 4.4 mg/g of consumed sugars, with optical purities of 95.0 ± 0.0 % and 93.8 ± 0.2 %, respectively. This study is the pioneer in demonstrating economical and sustainable ton-scale production of D-lactic acid.

OXIDATION OF 4-METHYLPYRIDINE ON V-Cr-O CATALYST

Isonicotinic acid derivatives are used in the development of new antibacterial agents, active ingredients in pesticides and herbicides. In addition, isonicotinic acid is a precursor for the synthesis of isoniazid, one of the most effective anti-TB drugs. Considering the importance of isoniazid in the treatment of tuberculosis, improving methods of synthesizing isonicotinic acid has a direct impact on the availability and cost of this life-saving drug. The goal of this work was to investigate the efficiency of V-Cr-O catalyst in the oxidation of 4-methylpyridine to produce isonicotinic acid, to study its composition and properties. Research methods. Methods of chemical analysis, scanning electron microscope (SEM), Raman spectroscopy were applied. Results and Discussion. In this work, the processes of isonicotinic acid synthesis by oxidation of 4-methylpyridine on the V-Cr-O catalyst were studied. Analysis of the obtained results showed that with an increase in the water feed, there is a general tendency towards a decrease in the conversion of 4-methylpyridine at all temperatures. For example, at a temperature 300oC, the degree of conversion drops from 91.72% at 1.79 g/h to 84.20% at 6.6 g/h. The yield of isonicotinic acid increases as the amount of water rises, reaching its peak at 47.46% with a temperature of 360°C and a water supply of 6.6 g/h. In contrast, the minimum yield is only 15.27% at 280°C with a water supply of 1.79 g/h. This highlights the positive correlation between water supply and yield, especially at higher temperatures.

Enhancement of Succinic Acid Production by Actinobacillus succinogenes in an Electro-Bioreactor

This work examines the electrochemically enhanced production of succinic acid using the bacterium Actinobacillus succinogenes. The principal objective is to enhance the metabolic potential of glucose and CO2 utilization via the C4 pathway in order to synthesize succinic acid. We report on the development of an electro-bioreactor system to increase succinic acid production in a power-2-X approach. The use of activated carbon fibers as electrode surfaces and contact areas allows A. succinogenes to self-initiate biofilm formation. The integration of an electrical potential into the system shifts the redox balance from NAD+ to NADH, increasing the efficiency of metabolic processes. Mediators such as neutral red facilitate electron transfer within the system and optimize the redox reactions that are crucial for increased succinic acid production. Furthermore, the role of carbon nanotubes (CNTs) in electron transfer was investigated. The electro-bioreactor system developed here was operated in batch mode for 48 h and showed improvements in succinic acid yield and concentration. In particular, a run with 100 µM neutral red and a voltage of −600 mV achieved a yield of 0.7 gsuccinate·gglucose−1. In the absence of neutral red, a higher yield of 0.72 gsuccinate·gglucose−1 was achieved, which represents an increase of 14% compared to the control. When a potential of −600 mV was used in conjunction with 500 µg∙L−1 CNTs, a 21% increase in succinate concentration was observed after 48 h. An increase of 33% was achieved in the same batch by increasing the stirring speed. These results underscore the potential of the electro-bioreactor system to markedly enhance succinic acid production.

Endogenous ethanol- and thermo-tolerant strain from Malaysia pineapple peel: Screening and molecular characterisation

The current study aims to identify an endogenous acetic acid bacterial strain isolated from a Malaysian pineapple capable of tolerating high ethanol and temperatures. A total of 23 strains of presumed acetic acid bacteria were isolated from the pineapple peel waste. Subsequently, three isolates with the highest acid yield were subjected to 16S rDNA sequencing; Acetobacter tropicalis (A. tropicalis), Staphylococcus haemolyticus, and Staphylococcus ureilyticus. Tolerance evaluations against pH, temperature, ethanol, sugar, and acetic acid demonstrated that all three strains tolerated significant temperatures, ethanol, and sugar levels. Based on the results, A. tropicalis possesses the potential to reduce cooling system load during acetic acid manufacture in hot climate regions with a notable acetic acid yield.

The Effect of Herbicides and Biostimulant Application on the Seed Yield and Seed Quality of Soybean (Glycine max (L.) Merr.)

The profitability of growing soybean (Glycine max (L.) Merr.) is largely determined by the successful elimination of weeds and the weather conditions, the adverse effect of which can be minimized by the use of biostimulants. This study aims to evaluate the effect of several herbicides and biostimulants on the seed yield and contents of protein, fat, amino acids, and fatty acids in soybean seeds. The results demonstrate that the yield and quality of soybean seeds were most beneficially affected by the use of prosulfocarb immediately after sowing in combination with a subsequent foliar application of bentazone and imazamox with an adjuvant containing methyl oleate and fatty alcohol. This treatment ensured the highest seed yield (3.32 t ha−1), the highest contents in seeds of protein (342.4 g kg−1 DM), phenylalanine (15.65 g kg−1 DM), leucine (23.54 g kg−1 DM), and most of the endogenous amino acids. All herbicide treatments increased the contents of tryptophan, serine, and glutamic acid compared to the seeds without herbicide treatment. The study results indicate that soybean responded positively to all biostimulants, as indicated by a higher seed yield (from 5.3% to 11.3%), plant height, and contents of tryptophan, serine, glutamic acid, cysteine, tyrosine, and C18:1n9c + C18:1n9t acids in the seeds.

Lactic acid production by fermentation of hydrolysate of the macroalga Gracilaria corticata by Lactobacillus acidophilus

Macroalgae (Ulva fasciata, Gracilaria corticata, and Sargassum wightii) were collected from the marine environment and used as the substrate for lactic acid production. These macroalgae were pretreated with hydrochloric acid (0.2 to 0.4 N) for various times (20 to 60 min). Additionally, the algal hydrolysate was incubated with cellulase for 24 h at 30 ± 1 °C to achieve enzymatic saccharification. Proximate analysis of these macroalgae was performed, and the yield was high in G. corticata. The G. corticata hydrolysate was composed of 10.01 ± 0.12% ash content, 1.25 ± 0.2% total fat, 10.2 ± 0.1% crude protein, 9.2 ± 0.2% moisture content, and a higher level of total carbohydrate (69.33 ± 1.5%) than the other two macroalgae. In G. corticata, the enzymatic treatment showed the maximum reducing sugar (33.5 ± 2.3%) relative to the other macroalgal hydrolysates and was considered for optimization of lactic acid production. Lactobacillus acidophilus (MTCC447) utilized pretreated G. corticata hydrolysate (enriched with 5% yeast extract), and maximum lactic acid yield was achieved after 72 h, 30 °C incubation temperature, and 6% inoculum (1×108 CFU/mL) in static culture condition. Batch fermentation was performed in the 1-L bioreactor at room temperature (30 °C) for 96 h. Lactic acid production was maximum within 72 h and the pH value was depleted. The present finding indicates that G. corticata could be used as a substrate for lactic acid production.