Supplemental Carbon Research Articles

Food Waste Fermentation Liquid as a Supplementary Carbon Source for Enhanced Biological Nitrogen Removal from Rural Wastewater

Food Waste Fermentation Liquid as a Supplementary Carbon Source for Enhanced Biological Nitrogen Removal from Rural Wastewater

A Technical-Economic Assessment of Producing Hydrogen and Biofuels via Gasification of Biomass in Solar Hybridised Dual Fluidised Bed

In this work, the techno-economic performances of three conversion pathways using an upstream solar hybridised dual fluidised bed (SDFB) for biomass gasification were assessed. The annual solar share % over the solar multiple range of 1.4-3.4 varies between 7-17%, with the CO2 emissions avoided relative to the non-solar case varying between 7%-23%, using representative solar viability location in Australia. The projected break-even price varies between 5.5-6.1 AUD/kg (3.8-4.25 USD/kg) for hydrogen, 1.1-1.2 AUD/kg (0.75-0.85 USD/kg) for methanol, and 1.5-1.7 AUD/L (1.1-1.2 USD/L) for liquid fuels over the analysed oversize level of 1.4 to 3.4 at thermal storage capacity designs with less than 1% solar dumping rate for base case scenario. Overall, the derived break-even price from the SDFB gasifier configuration is higher than that of the non-solar gasifier case, yet this is dependent on the cost of supplement heat supply and carbon credit

7205 Anaplastic Thyroid Carcinoma Presenting as New-Onset Thyrotoxicosis and Hypoparathyroidism in a Young Patient: A Diagnostic Dilemma between Hashitoxicosis and Anaplastic Thyroid Cancer

Abstract Disclosure: M. Sulehri: None. E.G. Bustamante: None. A. Elmaaz: None. A. Chaudhuri: None. Introduction: This case report explores the complex diagnostic challenges encountered in a young patient presenting with anaplastic thyroid carcinoma (ATC) manifested by thyrotoxicosis and hypoparathyroidism. Case report: A 29-year-old male who sought multiple emergency room visits for shortness of breath, was initially misdiagnosed with pneumonia. On the third visit, exacerbated respiratory distress led to intubation, CT of the neck and thyroid US unveiling an infiltrative mass centered within the region of the thyroid gland. Initial thyroid function tests showed TSH <0.02 uIU/mL, free thyroxine 6.91 ng/dL, and total T3 204 ng/dL indicating hyperthyroidism, promptly managed with Methimazole and beta blockade. Elevated TPO antibodies (194 unit/mL) were observed, whereas thyroglobulin antibodies and thyroid receptor antibodies were undetected. Concurrently, hypoparathyroidism was noted, marked by low calcium levels (7.9 mg/dL) with albumin of 3.4 g/dL (corrected Calcium 8.4), and low parathyroid hormone (PTH) (<6 pg/mL). Other labs showed ionized calcium 4.30 mg/dL, phosphate 4.6 mg/dL, magnesium 1.8 mg/dL, and vitamin D 54 ng/dl. The patient received calcium carbonate supplement, calcitriol and IV calcium gluconate. Thyrotoxicosis then transitioned to hypothyroidism and levothyroxine replacement therapy was initiated. Definitive diagnosis was delayed due to the patient's overall condition and a low suspicion of malignancy. Left thyroidectomy and tracheostomy were performed, revealing dense subplatysmal necrosis with tumor involvement of both thyroid lobes and isthmus with multiple enlarged nodes. Final surgical pathology confirmed the presence of anaplastic thyroid carcinoma. Due to poor prognosis, the patient was transferred to hospice care where the patient succumbed to his condition within a day. Conclusion: Anaplastic thyroid cancer is considered one the most aggressive and fastest growing tumors. Although it is usually seen in patients after the age of 60, we present a very rare case of ATC in a young patient in the third decade who was presented with infiltrative thyroiditis and hypoparathyroidism. The case underscores the importance of considering rare etiologies in patients with atypical clinical presentation. Presentation: 6/1/2024

Calcium carbonate supplementation for the prevention of preeclampsia in high-risk pregnant women: a randomized clinical trial protocol

BackgroundPreeclampsia (PE) is a significant cause of maternal mortality worldwide, affecting 2% to 8% of pregnancies. The World Health Organization recommends the use of low-dose acetylsalicylic acid (100 mg of aspirin) and 1.5 to 2 g of calcium carbonate during pregnancy to prevent PE. However, robust evidence supporting the efficacy of calcium supplementation is still needed. This study aims to assess the efficacy of calcium carbonate in preventing preeclampsia in high-risk pregnant women.MethodsA triple-blind, randomized clinical trial will be conducted at an outpatient clinic in Brazil between May 2024 and March 2026. Pregnant women at high risk of developing preeclampsia and with low dietary calcium intake will be randomly assigned to one of three groups: one group will receive calcium carbonate capsules (commercially available in Brazil) along with 100 mg of aspirin; the second group will receive calcium carbonate derived from Crassostrea sp. along with 100 mg of aspirin; and the control group will receive a placebo alongside 100 mg of aspirin. The primary outcome is the diagnosis of preeclampsia during pregnancy, while secondary outcomes evaluate maternal and fetal health indicators.DiscussionThis trial seeks to generate evidence on the efficacy of calcium carbonate in preeclampsia prevention, with a focus on comparing industrial calcium carbonate with calcium carbonate sourced from Crassostrea sp., a more sustainable alternative.Trial registrationThe study was approved by the Research Ethics Committee of the Federal University of Sergipe and registered in the Brazilian Registry of Clinical Trials (ReBEC), under the ID RBR-7hqhj3y. Registered on November 16, 2023.

Maximizing diclofenac bioremoval efficiency using Chlorella vulgaris strain H1 and Chlorella sorokiniana strain H2: Unveiling the impact of acetic acid on microalgae

BackgroundDiclofenac (DFC) is a commonly detected pharmaceutical pollutant in wastewater, posing environmental risks. Microalgae have emerged as potential candidates for bioremediation due to their ability to degrade pollutants. This study focuses on investigating the biodegradation potential of two newly isolated microalgae strains, Chlorella vulgaris strain H1 and Chlorella sorokiniana strain H2, towards DFC removal. The optimization of pH is crucial for enhancing the efficiency of bioremediation processes. Therefore, in addition to assessing the biodegradation potential of microalgae, this study also investigates the impact of adjusting the pH of the culture medium using acetic acid as an additional carbon source on the biodegradation process. MethodsThrough genetic analysis using 18S rDNA sequencing, the microalgae strains were identified. Various parameters including growth dynamics, chlorophyll content, cell proliferation, photosynthetic activity, and DFC biodegradation efficiency were comprehensively assessed. Additionally, the impact of incorporating acetic acid as an additional carbon source in the culture medium on the biodegradation process was examined. Significant FindingsC. sorokiniana strain H2 demonstrated superior biodegradation rates compared to C. vulgaris strain H1 across varying DFC concentrations. Specifically, C. sorokiniana strain H2 exhibited remarkable biodegradation rates of 84 %, 83.72 %, and 29.57 % for DFC concentrations of 12.5 mg L−1, 25 mg L−1, and 100 mg L−1, respectively. In contrast, C. vulgaris strain H1 showed lower biodegradation rates of 66.64 %, 29.24 %, and 1.83 % for the corresponding DFC concentrations. The study highlights the potential of C. sorokiniana strain H2 as a promising candidate for the removal of pharmaceutical pollutants like DFC from wastewater. Furthermore, the use of acetic acid as a supplementary carbon source enhanced the biodegradation efficiency, suggesting a potential strategy for optimizing bioremediation processes.

Acupuncture in Treating Osteopenia: A Multicenter, Randomized, Controlled Clinical Trial

Introduction: The aim of this study was to analyze the effectiveness of acupuncture as an early intervention in the treatment of osteoporosis and prevention of osteoporosis. Methods: This multicenter, randomized, controlled clinical trial was conducted in 226 patients with osteoporosis for 6 months. Participants were randomized to the control group (n = 110) and the acupuncture group (n = 116), both groups received basic treatment with daily calcium carbonate and vitamin D3 tablet (containing calcium 600 mg/tablet) supplementation (n = 116), and the acupuncture group received additional acupuncture treatment. Bone mineral density (BMD), Berg Balance Scale (BBS), bone metabolism indexes, and lower limb muscle strength and balance indexes were tested to evaluate the therapy outcomes of the two groups. Results: After 6 months of treatment, BBS11 (p = 0.046), BBS12 (p = 0.042), and total BBS scores (p = 0) in the acupuncture group were significantly higher than those before treatment; comparing between groups, BBS8 in the acupuncture group was higher than that in the control group after 3 and 6 months, with statistically significant differences (p = 0.036 and 0.0270). After 6 months of treatment, the total BBS score of the acupuncture group was significantly higher than that of the control group, and the difference was statistically significant (p = 0.039). After 6 months of treatment, the BMD of total bone of femoral neck (p = 0.031) and hip joint (p = 0.013) in the acupuncture group was significantly higher than that before treatment, but there was no statistical difference with the control group. The time of five sit-to-stand test (FTSST) was shortened in the acupuncture group, and the difference was statistically significant (p = 0.023), but there was no significant change in the control group (p > 0.05). In addition, the specific sequences of blood phosphorus (p = 0.007), β-collagen (p = 0.009), and N-osteocalcin (p = 0.007) were significantly lower than before treatment after 3 months of acupuncture treatment, and the blood phosphorus level continued to decrease after 6 months of treatment (p = 0.007). In addition, the levels of N-osteocalcin in the acupuncture group were significantly lower than those in the control group after 3 months of treatment (p = 0.008). Conclusion: Acupuncture can increase hip bone density, improve bone metabolism, reduce bone turnover rate, and improve body balance and lower limb muscle strength in patients with osteoporosis.

Biological characteristics of marine Streptomyces SK3 and optimization of cultivation conditions for production of compounds against Vibiriosis pathogen isolated from cultured white shrimp (Litopenaeus vannamei).

Antibiotic resistance in shrimp farms has emerged as an extremely serious situation worldwide. The main aim of this study was to optimize the cultural conditions for producing new antibiotic agents from marine Streptomyces species. Streptomyces SK3 was isolated from marine sediment and was identified by its 16S rDNA as well as biochemical characteristics. This microbe produced the highest concentration of bioactive secondary metabolites (BSMs) when cultured in YM medium (YM/2). It produced the maximum total protein (41.8 ± 6.36 mg/ml) during the late lag phase period. The optimum incubation temperature was recorded at 30 °C; BSMs were not produced at ≤10 °C within an incubation period of 3-4 days. The suitable agitation speed was found to be 200 rpm with pH 7.00. The proper carbon, nitrogen, and trace elements supplementation consisted of starch, malt extract, calcium carbonate (CaCO3), and magnesium sulfate (MgSO4). The ethyl acetate extract was found to act strongly against three vibriosis pathogens, Vibrio harveyi, Vibrio parahaemolyticus, and Vibrio vunificus, as indicated by the inhibition zones at 34.5, 35.4, and 34.3 mm, respectively. The extract showed the strongest anti-V. harveyi activity, as indicated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.101 ± 0.02 and 0.610 ± 0.04 mg/ml, respectively. Basic chemical investigation of the crude extract using thin layer chromatography (TLC), bioautography, liquid chromatography tandem mass spectrometry (LC‒MS/MS), Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (1H-NMR) revealed that the active components were the terpenoid and steroid groups of compounds. They showed carboxylic acid and ester functions in their molecules.

Effect of NH4Cl supplementation on growth, photosynthesis, and triacylglycerol content in Chlamydomonas reinhardtii under mixotrophic cultivation.

Ammonium chloride (NH4Cl) is one of the nitrogen sources for microalgal cultivation. An excessive amounts of NH4Cl are toxic for microalgae. However, combining mixotrophic conditions and excessive quantities of NH4Cl positively affects microalgal biomass and lipid production. In this study, we investigated the impact of NH4Cl on the growth, biomass, and triglyceride (TAG) content of the green microalga Chlamydomonas reinhardtii especially under mixotrophic conditions. Under photoautotrophic conditions (without organic carbon supplementation), adding 25 mM NH4Cl had no significant effect on microalgal growth or TAG content. However, under mixotrophic condition (with acetate supplementation), NH4Cl interfered with microalgal growth while inducing TAG content. To explore these effects further, we conducted a two-step cultivation process and found that NH4Cl reduced microalgal growth, but induced total lipid and TAG content, especially after 4-day cultivation. The photosynthesis performances showed that NH4Cl completely inhibited oxygen evolution on day 4. However, NH4Cl slightly reduced the Fv/Fm ratio indicating that the NH4Cl supplementation directly affects microalgal photosynthesis. To investigate the TAG induction effect by NH4Cl, we compared the protein expression profiles of microalgae grown mixotrophically with and without 25 mM NH4Cl using a proteomics approach. This analysis identified 1782 proteins, with putative acetate uptake transporter GFY5 and acyl-coenzyme A oxidase being overexpressed in the NH4Cl-treated group. These findings suggested that NH4Cl supplementation may stimulate acetate utilization and fatty acid synthesis pathways in microalgae cells. Our study indicated that NH4Cl supplementation can induce microalgal biomass and lipid production, particularly when combined with mixotrophic conditions.

Biodegradation of organosulfur with extra carbon source: Insights into biofilm formation and bacterial metabolic processes

Organosulfur compounds are prevalent in wastewater, presenting challenges for biodegradation, particularly in low-carbon environments. Supplementing additional carbon sources not only provides essential nutrients for microbial growth but also serves as regulators, influencing adaptive changes in biofilm and enhancing the survival of microorganisms in organosulfur-induced stress bioreactors. This study aims to elucidate the biodegradation of organosulfur under varying carbon source levels, placing specific emphasis on functional bacteria and metabolic processes. It has been observed that higher levels of carbon supplementation led to significantly improved total sulfur (TS) removal efficiencies, exceeding 83 %, and achieve a high organosulfur CH3SH removal efficiency of ~100 %. However, in the reactor with no external carbon source added, the oxidation end-product SO42− accumulated significantly, surpassing 120 mEq/m2-day. Furthermore, the TB-EPS concentration consistently increasedwith the ascending glucose concentration. The analysis of bacterial community reveals the enrichment of functional bacteria involved in sulfur metabolism and biofilm formation (e.g. Ferruginibacter, Rhodopeudomonas, Gordonia, and Thiobacillus). Correspondingly, the gene expressions related to the pathway of organosulfur to SO42− were notably enhanced (e.g. MTO increased by 27.7 %). In contrast, extra carbon source facilitated the transfer of organosulfur into amino acids in sulfur metabolism and promoted assimilation. These metabolic insights, coupled with kinetic transformation results, further validate distinct sulfur pathways under different carbon source conditions. The intricate interplay between bacteria growth regulation, pollutant biodegradation, and microbial metabolites underscores a complex network relationship that significantly contributes to efficient operation of bioreactors.

Large-scale cultivation of Synechocystis sp. PCC6803 for the production of Poly(3-hydroxybutyrate) and its potential applications in the manufacturing of bulk and medical prototypes

Polyhydroxyalkanoates (PHAs) are biopolymers produced by microorganisms under nutrient limiting conditions and in the presence of excess carbon source. PHAs have gained popularity as a sustainable alternative to traditional plastics. However, large scale production of PHAs is economically challenging due to the relatively high costs of organic carbon. Alternative options include using organisms capable of phototrophic or mixotrophic growth. This study aimed at the production of poly(3-hydroxybutyrate) P(3HB), a type of PHA, at pilot scale using the freshwater cyanobacterium Synechocystis sp. PCC6803. First, to identify optimal conditions for P(3HB) production from Synechocystis sp. PCC6803, different supplemental carbon source concentrations and salinity levels were tested at laboratory scale. The addition of 4 g/L acetate with no added NaCl led to P(3HB) accumulation of 10.7 % dry cell weight on the 28th day of cultivation. Although acetate additions were replicated in an outdoor 400 L serpentine photobioreactor, P(3HB) content was lower, implying uncontrolled conditions impact on biopolymer production efficiency. An optimized P(3HB) extraction methodology was developed to remove pigments, and the biopolymer was characterized and subjected to 3D printing (fused deposition modelling) to confirm its processability. This study thus successfully led to the large-scale production of P(3HB) using sustainable and environmentally friendly cyanobacterial fermentation.

Inorganic carbon metabolism enhanced hydrogen-driven denitrification: Evaluation of carbon fixation pathways and microbial traits

H2-driven denitrification offers a promising alternative for treating low C/N wastewater amidst global nitrogen pollution, due to its advantages of high removal efficiency, low energy consumption, and independence from exogenous organic carbon source. While inorganic carbon assimilation is crucial for the growth and reproduction of autotrophic microorganisms, it remains uncertain whether the fixation of inorganic carbon could impact H2-driven denitrification. This work demonstrated that the supplement of inorganic carbon efficiently improved the efficiency of nitrate removal to 90.3%, compared to 78.0% in the control. Further analysis indicated that inorganic carbon supplementation shifted the microbial structure from autotrophic-dominated (e.g., Hydrogenophaga and Rhodococcus with abundance of 2.3% and 2.6%) to mixotrophic-dominated (e.g., Thauera and Microscillaceae sp. with abundance of 5.6% and 32.8%). Additionally, although H2 boosted the carbon fixation via the reductive TCA cycle and Wood-Ljungdahl pathway, the Calvin-Benson cycle emerged as the predominant pathway, significantly boosted under inorganic carbon supplementation, along with the upregulation of critical enzyme expression including RuBisCo (EC 4.1.1.39), PGK (EC 2.7.2.3) and GAPDH (EC 1.2.1.12). Moreover, the expressions and activities of functional enzymes involved in nitrogen transformation, including nitrate reductase (NAR), nitrite reductase (NIR) and nitric oxide reductase (NOR), as well as microbial electron transfer ability, were remarkably enhanced under sufficient inorganic carbon conditions. This work contributed to understanding the carbon metabolism mechanism in H2-driven denitrification, thereby facilitating the promotion of the efficient and low-carbon approach for nitrogen removal from wastewater.

Effects of engineering injection and supplement mode of in-situ biogeochemical transformation enhancement EVO-FeSO4 on the remediation of tetrachloroethylene contaminated aquifer

Traditional in situ biogeochemical transformation suffers from competition among crucial microorganisms and inadequate formation of reactive minerals, thus leading to the accumulation of toxic intermediates. In this study, three regulation schemes were proposed to solve these problems from the perspective of engineering mode. Results showed intermittent injection mode effectively reduced the accumulation of toxic intermediates but the reduction rate of tetrachloroethylene was decreased. And periodical supplementation of carbon and sulfur sources accelerated the removal of tetrachloroethylene but failed to reduce the accumulation of toxic products. While, regular supplementation of sulfate effectively weakened the competition of methanogens and increased the iron sulfide proportion on the surface of the minerals, thus reducing the accumulation of toxicity. Based on the results, this study obtained an effective engineering approach for practical site application. In addition, the main forms of active minerals capable of β-eliminating contaminants during biogeochemical transformation were identified in this study, including FeS, FeS2, and Fe3S4. Furthermore, the engineered regulatory mechanism of this study was summarized through the analysis of microbial community structure and mineral morphology. The amendment promotes the production of minerals and thus controls the transformation pathway of contaminants by altering the abundance of sulfate-reducing bacteria and dissimilatory iron reducing bacteria. This mechanism can provide a basis for subsequent theoretical studies.

Electrochemical detection of poly(3-hydroxybutyrate) production from Burkholderia glumae MA13 using a molecularly imprinted polymer-reduced graphene oxide modified electrode.

Thedevelopment and application of an electrochemical sensor is reported fordetection of poly(3-hydroxybutyrate) (P3HB) - a bioplastic derived from agro-industrial residues. To overcome the challenges of molecular imprinting of macromolecules such as P3HB, this study employed methanolysis reaction to break down the P3HB biopolymer chains into methyl 3-hydroxybutyrate (M3HB) monomers. Thereafter, M3HB were employed as the target molecules in the construction of molecularly imprinted sensors. The electrochemical device was then prepared by electropolymerizing a molecularly imprinted poly (indole-3-acetic acid) thin film on a glassy carbon electrode surface modified with reduced graphene oxide (GCE/rGO-MIP) in the presence of M3HB. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscopy with field emission gun (SEM-FEG), Raman spectroscopy, attenuated total reflection Fourier-transform infrared (ATR-FTIR) and X-ray Photoelectron Spectroscopy (XPS) were employed to characterize the electrode surface. Under ideal conditions, the MIP sensor exhibited a wide linear working range of 0.1 - 10nM and a detection limit of 0.3pM (n = 3). The sensor showed good repeatability, selectivity, and stability over time. For the sensor application, the bioproduction of P3HB was carried out in a bioreactor containing the Burkholderia glumae MA13 strain and sugarcane byproducts as a supplementary carbon source. The analyses were validated through recovery assays, yielding recovery values between 102 and 104%. These results indicate that this MIP sensor can present advantages in the monitoring of P3HB during the bioconversion process.

Update: Vitamin D3 and calcium carbonate supplementation for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology (VITALITY trial): study protocol for a randomised placebo-controlled trial

BackgroundOf the 2 million children living with HIV globally, 90% live in sub-Saharan Africa. Despite antiretroviral therapy, longstanding HIV infection is associated with several chronic complications in children including growth failure, particularly stunting and delayed puberty. Vitamin D deficiency, which is highly prevalent among children living with HIV in sub-Saharan Africa, has further adverse impact on bone health. This trial aims to establish whether supplementation with vitamin D3 and calcium carbonate improves musculoskeletal health among peripubertal children living with HIV. This paper is an update to an already existing protocol that was previously published in Trials in 2022 and details changes in the trial outcomes.Methods/designWe will conduct an individually randomised, double-blinded, placebo-controlled trial of weekly high-dose vitamin D3 (20,000 IU) plus daily calcium carbonate (500 mg) supplementation for 48 weeks. Eight hundred and forty children living with HIV aged 11–19 years taking ART for ≥ 6 months will be enrolled and followed up for 96 weeks. The primary outcome is DXA-measured total body less-head bone mineral density Z-score (TBLH-BMD) at 48 weeks and is an update to the previous primary outcome total body less-head bone mineral content adjusted for lean mass (TBLH-BMCLBM) Z-score. The primary outcome was updated to address the substantial differences in distributions of TBLH-BMCLBM Z-score between the two sites as a result of software differences of the DXA machines. Secondary outcomes are DXA-measured TBLH-BMD Z-score adjusted for height at 48 weeks a new secondary outcome, lumbar spine bone mineral apparent density Z-score, number of respiratory infections, lean muscle mass and grip-strength at 48 and 96 weeks, and TBLH-BMD Z-score at 96 weeks. Sub-studies will investigate the effect of the intervention on vitamin D3 pathway metabolites and markers of bone turnover, intestinal microbiota, and innate and acquired immune function.DiscussionThis is the largest trial to date of vitamin D supplementation in children living with HIV. Intervening to address deficits in bone accrual through childhood is critical for optimising adolescent and early adult bone health, and prevention of later adult osteoporotic fractures. Trial results will draw attention to the need to screen for and treat long-term comorbidities in children living with HIV in resource-limited settings.Trial registrationPan African Clinical Trials Registry PACTR20200989766029. Registered on September 3, 2020. URL of trial registry record: https://pactr.samrc.ac.zaTrial statusParticipant follow-up completed; data analysis ongoing.

Optimizing nitrogen removal in constructed wetlands for low C/N ratio wastewater treatment: Insights from fermentation liquid utilization

The inefficient nitrogen removal in constructed wetlands (CWs) can be attributed to insufficient carbon sources for low carbon-to-nitrogen (C/N) ratio wastewater. In this study, sugarcane bagasse fermentation liquid (SBFL) was used as a supplemental carbon source in intermittently aerated CWs to enhance nitrogen removal. The impact of different regulated influent C/N ratios on nitrogen removal and greenhouse gas (GHG) emissions was investigated. Results demonstrated that SBFL addition significantly enhanced the denitrification capacity, resulting in faster NO3--N removal compared to sucrose. Moreover, intermittently aerated CWs significantly improved NH4+-N removal efficiency compared to non-aerated CWs. The highest total nitrogen removal efficiency (98.3 %) was achieved at an influent C/N ratio of 5 in intermittently aerated CWs with SBFL addition. The addition of SBFL resulted in a reduction of N2O emissions by 17.8 %–43.7 % compared to sucrose. All CWs exhibited low CH4 emissions, with SBFL addition (0.035–0.066 mg·m-2h-1) resulting in lower emissions compared to sucrose. Additionally, higher abundance of denitrification (nirK, nirS and nosZ) genes as well as more abundant denitrifying bacteria were shown in CWs of SBFL inputs. The results of this study provide a feasible strategy for applying SBFL as a carbon source to improve nitrogen removal efficiency and mitigate GHG emissions in CWs.

Mitigating nitrous oxide emissions from low carbon to nitrogen ratio wastewater treatment: Utilizing sugarcane bagasse fermentation liquid for constructed wetlands

Sugarcane bagasse was recycled to produce fermentation liquid (FL) as a supplementary carbon source that was added to constructed wetlands (CWs) for regulating influent carbon to nitrogen ratio (C/N), and then being applied to investigate nitrogen transformations and greenhouse gas emissions. Results showed that this FL achieved faster NO3−-N removal and lower N2O fluxes than sucrose did, and the lowest N2O flux (67.6 μg m−2h−1) was achieved when FL was added to CWs in a C/N of 3. In contrast, CH4 emissions were higher by the FL addition than by the sucrose addition, although the fluxes under both additions were in a lower range of 0.06–0.17 mg m−2h−1. The utilization of FL also induced significant variations in microbial communities and increased the abundance of denitrification genes. Results showed the application of FL from sugarcane bagasse can be an effective strategy for improving nitrogen removal and mitigating N2O emissions in CWs.

Optimization of the production of Exopolysaccharide (EPS) from biofilm-forming bacterial consortium using different parameters

Bacterial cells produce a variety of exopolysaccharide (EPS) throughout their life cycle. EPS plays a crucial role in the formation of biofilms and the control of environmental processes in microbial communities. The bacterial community benefits from biofilms in several ways, including nutrient compartmentation and storage, environmental stress resistance and synergism. The generation of EPS by consortium-associated bacteria, which involves a variety of microorganisms, is versatile and efficient for use in industrial and environmental processes, such as biotechnology and pollution degradation. The qualitative and quantitative chemical characteristics of the consortium's EPS are mostly determined by the type of culture utilized, nutrient type, temperature, and pH. The main goal of the study was to find out how EPS biosynthesis works in a bacterial consortium culture. To achieve maximum EPS regeneration, pH, temperature, carbon, and nitrogen sources were optimized. A consortium of three bacterial strains i.e. Klebsiella pneumonia strain, Pseudomonas aeruginosa strain and Burkholderia cepacian strain that were distinguished by their capacity to produce biofilms were developed as part of the study. The maximum total EPS production was detected after 8 days of incubation at pH 7.5 (15.5 g/L) and a temperature of 35 °C (12.60 g/L). The optimum EPS production was identified as 17.84 g/L and 21.07 g/L when ammonium sulfate and glucose were employed as nitrogen and carbon supplements, respectively. The protein concentration of the EPS was 3067 µg/mL, which was more than the carbohydrate (263.10 µg/mL) and DNA (7.60 µg/mL) content. The total protein/carbohydrate ratio of the EPS detected in the present study was 11.65, which was much higher than in prior investigations. FTIR analysis of EPS confirmed the functional groups of carbohydrates, proteins, lipids and DNA, viz., CO, COOH, NH, OH, CH and OCH3. The study's findings revealed that enhancing the consortium's EPS molecules involves lowering biofilm-related infections and improving the efficacy of antimicrobial treatments in wastewater.

Supplementation of calcium magnesium carbonate, tylosin phosphate, or both on growth performance, carcass traits, liver outcomes, and rumination activity of yearling beef steers fed a finishing diet*

Supplementation of calcium magnesium carbonate, tylosin phosphate, or both on growth performance, carcass traits, liver outcomes, and rumination activity of yearling beef steers fed a finishing diet*

Enhanced biomass production and harvesting efficiency of Chlamydomonas reinhardtii under high-ammonium conditions by powdered oyster shell

Chlamydomonas reinhardtii prefers ammonium (NH4+) as a nitrogen source, but its late-stage growth under high-NH4+ concentrations (0.5 ∼ 1 g/L) is retarded due to medium acidification. In this study, oyster shell powders were shown to increase the tolerance of C. reinhardtii to NH4+ supplementation at 0.7 g/L in TAP medium in 1-L bubble-column bioreactors, resulting in a 22.9 % increase in biomass production, 62.1 % rise in unsaturated fatty acid accumulation, and 19.2 % improvement in harvesting efficiency. Powdered oyster shell mitigated medium acidification (pH 7.2–7.8) and provided dissolved inorganic carbon up to 8.02 × 103 μmol/L, facilitating a 76.3 % NH4+ consumption, release of up to 189 mg/L of Ca2+, a 42.1 % reduction in ζ-potential and 27.7 % increase in flocculation activity of microalgae cells. This study highlights a promising approach to utilize powdered oyster shell as a liming agent, supplement carbon source, and bio-flocculant for enhancing biomass production and microalgae harvesting in NH4+-rich environments.

Ibuprofen degradation by mixed bacterial consortia: Metabolic pathway and microbial community analysis

Degradation of ibuprofen, one of the most consumed drugs globally, by a mixed bacterial consortium was investigated. A contaminated hospital soil was used to enrich a bacterial consortium possessing the ability to degrade 4 mg/L ibuprofen in 6 days, fed on 6 mM acetate as a supplementary carbon source. Maximum ibuprofen degradation achieved was 99.51%, and for optimum ibuprofen degradation modelled statistically, the initial ibuprofen concentration, and temperature were determined to be 0.515 mg/L and 35 °C, respectively. The bacterial community analyses demonstrated an enrichment of Pseudomonas, Achromobacter, Bacillus, and Enterococcus in the presence of ibuprofen, suggesting their probable association with the biodegradation process. The biodegradation pathway developed using open-source metabolite predictors, GLORYx and BioTransformer suggested multiple degradation routes. Hydroxylation and oxidation were found to be the major mechanisms in ibuprofen degradation. Mono-hydroxylated metabolites were identified as well as predicted by the bioinformatics-based packages. Oxidation, dehydrogenation, super-hydroxylation, and hydrolysis were some other identified mechanisms.