Search results for: enzymatic composting bioreactor

Authors: Kanchan Vishwakarma, Shivesh Sharma, Nitin Kumar

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Soil is incoherent matter on Earth’s surface having organic and mineral content. The spatial variation of 4 soil enzyme activities and microbial biomass were assessed for two seasons’ viz. monsoon and winter along the latitudinal gradient in North-central India as the area of this study is fettered with respect to national status. The study was facilitated to encompass the effect of climate change, enzyme activity and biomass on nutrient cycling. Top soils were sampled from 4 sites in North-India. There were significant correlations found between organic C, N & P wrt to latitude gradient in two seasons. This distribution of enzyme activities and microbial biomass was consequence of alterations in temperature and moisture of soil because of which soil properties change along the latitude transect.

Keywords: latitude gradient, microbial biomass, moisture, soil, organic carbon, temperature

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Authors: Mustafa Abu Ghalia, Mohammed Seddik

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The design and development of a new class of biomaterial has gained particular interest in producing polymer scaffold for biomedical applications. Improving mechanical properties, biological and controlling pores scaffold are important factors to provide appropriate biomaterial for implement in soft tissue repair and regeneration. In this study, poly-ε-caprolactone (PCL) /polyethylene glycol (PEG) copolymer (80/20) incorporated with CNF scaffolds were made employing solvent casting and particulate leaching methods. Four mass percentages of CNF (1, 2.5, 5, and 10 wt.%) were integrated into the copolymer through a silane coupling agent. Mechanical properties were determined using Tensile Tester data acquisition to investigate the effect of porosity, pore size, and CNF contents. Tensile strength obtained for PCL/PEG- 5 wt.% CNF was 16 MPa, which drastically decreased after creating a porous structure to 7.1 MPa. The optimum parameters of the results were found to be 5 wt.% for CNF, 240 μm for pore size, and 83% for porosity. Scanning electron microscopy (SEM) micrograph reveals that consistent pore size and regular pore shape were accomplished after the addition of CNF-5 wt. % into PCL/PEG. The results of mass loss of PCL/PEG reinforced-CNF 1% have clearly enhanced to double values compared with PCL/PEG copolymer and three times with PCL/PEG scaffold-CNF 1%. In addition, all PCL/PEG reinforced and scaffold- CNF were partially disintegrated under composting conditions confirming their biodegradable behavior. This also provides a possible solution for the end life of these biomaterials.

Keywords: PCL/PEG, cellulose nanofibers, tissue engineering, biodegradation, compost polymers

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Authors: N. Anusree, P. Sughosh, G. L. Sivakumar Babu

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Municipalities throughout the world are marred with serious issues related to the Municipal Solid Waste (MSW) collection, treatment, and safe disposal. While the Waste Management sector contributes around 3-9 % of the overall anthropogenic methane emission, measures towards mitigating these emissions are rarely given attention in developing countries. In the case of Bangalore, India, around 5680 tons of MSW is generated in a day, and its collection and treatment efficiency are around 90-95 % and 26.4 %, respectively. About 33.4 % of the waste collected is directly landfilled without any treatment, further aggravating the situation. The potential of reducing the emissions emanating from the MSW of Bangalore city without any severe consequences on the current MSW management practices is evaluated in this study. Three emission scenarios consisting of the baseline condition (current practices – Case-1), the application of biocovers for methane oxidation in the dumpsites (case-2), and the diversion of Organic Fraction of MSW (OFMSW) along with the application of biocovers (case-3) are evaluated and compared with each other. The emissions are calculated based on the aerobic and anaerobic stochiometric relations for the three scenarios. Laboratory scale column studies are carried out to determine the methane oxidation potential of three different biocover material (digested MBT (mechanically biologically treated) waste, Fresh MBT waste, and charcoal amended with fresh MBT waste). The results shown that around 40 % and 83 % reduction in carbon emissions can be achieved in case 3 and 2 in comparison to the baseline condition. The study clearly shows that with minor changes in the waste management practices, substantial reductions in the carbon emissions can be attained in Bangalore City.

Keywords: MSW, biocover, composting, carbon emission

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Authors: Brayan Daniel Riascos Arteaga, Carlos Costa Perez

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Landfill leachate has an important fraction of humic substances, mainly humic acids (HAs), which often represent more than half value of COD, specially in liquids proceeded from composting processes of organic fraction of solid wastes. We propose in this article a new method of pH sensitive flocculation for COD and colour reduction in landfill leachate based on the chemical properties of HAs. Landfill leachate with a high content of humic acids can be efficiently treated by pH sensitive flocculation at pH 2.0, reducing COD value in 86.1% and colour in 84.7%. Mechanism of pH sensitive flocculation is based in protonation first of phenolic groups and later of carboxylic acid groups in the HAs molecules, resulting in a reduction of Zeta potential value. For pH over neutrality, carboxylic acid and phenolic groups are ionized and Zeta potential increases in absolute value, maintaining HAs in suspension as colloids and conducting flocculation to be obstructed. Ionized anionic groups (carboxylates) can interact electrostatically with cations abundant in leachate (site binding) aiding to maintain HAs in suspension. Simulation of this situation and ideal visualization of Zeta potential behavior is described in the paper and aggregation of molecules by H-bonds is proposed as the main step in separation of HAs from leachate and reduction of COD value in this complex liquid. CHNS analysis, FT-IR spectrometry and UV–VIS spectrophotometry show chemical elements content in the range of natural and commercial HAs, clear aromaticity and carboxylic acids and phenolic groups presence in the precipitate from landfill leachate

Keywords: landfill leachate, humic acids, COD, chemical treatment, flocculation

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Authors: Ivana Brzonova, Asina Fnu, Alena Kubatova, Evguenii Kozliak, Yun Ji

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Bio-decomposition of lignin by Basidiomycetes in the presence of dimethyl sulfoxide (DMSO) was investigated. The addition of 3-5 vol% DMSO to lignin aqueous media significantly increased the lignin solubility based on UV absorbance. After being dissolved in DMSO, the thermal evolution profile also changed significantly, yielding more high-MW organic carbon at the expense of recalcitrant elemental carbon. Medical fungi C. versicolor, G. lucidum and P. pulmonarius, were observed to grow on the lignin in media containing up to 15 vol. % DMSO. Further detailed product characterization by chromatographic methods corroborated these observations, as more low-MW phenolic products were observed with DMSO as a co-solvent. These results may be explained by the high solubility of lignin in DMSO; thus, the addition of DMSO to the medium increases the lignin availability for microorganisms. Some of these low-MW phenolic products host a big potential to be used in medicine. No significant inhibition of enzymatic activity (laccase, MnP, LiP) was observed by the addition of up to 3 vol% DMSO.

Keywords: basidiomycetes, bio-degradation, dimethyl sulfoxide, lignin

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Authors: Venkat Garigapati

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To date, more than a dozen oligonucleotide products are approved as injectable products for clinical use. However, there is no single oligo nucleotide product approved for clinical use. Oral delivery of oligo nucleotides is patient friendly administration however, many challenges involved in the development of oral formulation. Over the course of last twenty plus years, the research in this space aimed to address these challenges. This paper describes the issues involved in solubility, stability, enzymatic (nuclease) induced degradation, and permeation of nucleotides in the Gastrointestinal (GI) and how to overcome these challenges. Also, the translation of in vitro data to in vivo models hinders the formulation development. This paper describes the challenges involved in the development of Oligo Nucleotide products for oral administration. It also discusses the chemistry and formulation strategies for oral administration of oligonucleotides.

Keywords: oral adminstration, oligo nucleotides, stability, permeation, gastrointestinal tract

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Authors: Nusrat Masood, Vijaya Dubey, Suaib Luqman

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Caspase 3, a member of cysteine-aspartic acid protease family, is an imperative indicator for cell death particularly when substantiating apoptosis. Thus, caspase 3 is an interesting target for the discovery and development of anticancer agent. We adopted a four level assessment of both terpenoids and flavonoids and thus experimentally performed the enzymatic assay in cell free system as well as in cancer cell line which was validated through real time expression and molecular interaction studies. A significant difference was observed with both the class of natural products indicating terpenoids as better activators of caspase 3 compared to flavonoids both in the cell free system as well as in cell lines. The expression analysis, activation constant and binding energy also correlate well with the enzyme activity. Overall, terpenoids had an unswerving effect on caspase 3 in all the tested system while flavonoids indirectly affect enzyme activity.

Keywords: Caspase 3, terpenoids, flavonoids, activation constant, binding energy

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Authors: Dimitra C. Banti, Gesthimani Liona, Petros Samaras, Manasis Mitrakas

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Municipal and industrial wastewaters are often treated biologically, by the activated sludge process (ASP). The ASP not only requires large aeration and sedimentation tanks, but also generates large quantities of excess sludge. An alternative technology is the membrane bioreactor (MBR), which replaces two stages of the conventional ASP—clarification and settlement—with a single, integrated biotreatment and clarification step. The advantages offered by the MBR over conventional treatment include reduced footprint and sludge production through maintaining a high biomass concentration in the bioreactor. Notwithstanding these advantages, the widespread application of the MBR process is constrained by membrane fouling. Fouling leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary and resulting to increased operating costs. In general, membrane fouling results from the interaction between the membrane material and the components in the activated sludge liquor. The latter includes substrate components, cells, cell debris and microbial metabolites, such as Extracellular Polymeric Substances (EPS) and Sludge Microbial Products (SMPs). The challenge for effective MBR operation is to minimize the rate of Transmembrane Pressure (TMP) increase. This can be achieved by several ways, one of which is the addition of specific additives, that enhance the coagulation and flocculation of compounds, which are responsible for fouling, hence reducing biofilm formation on the membrane surface and limiting the fouling rate. In this project the effectiveness of a non-commercial composite coagulant was studied as an agent for fouling control in a lab scale MBR system consisting in two aerated tanks. A flat sheet membrane module with 0.40 um pore size was submerged into the second tank. The system was fed by50 L/d of municipal wastewater collected from the effluent of the primary sedimentation basin. The TMP increase rate, which is directly related to fouling growth, was monitored by a PLC system. EPS, MLSS and MLVSS measurements were performed in samples of mixed liquor; in addition, influent and effluent samples were collected for the determination of physicochemical characteristics (COD, BOD5, NO3-N, NH4-N, Total N and PO4-P). The coagulant was added in concentrations 2, 5 and 10mg/L during a period of 2 weeks and the results were compared with the control system (without coagulant addition). EPS fractions were extracted by a three stages physical-thermal treatment allowing the identification of Soluble EPS (SEPS) or SMP, Loosely Bound EPS (LBEPS) and Tightly Bound EPS (TBEPS). Proteins and carbohydrates concentrations were measured in EPS fractions by the modified Lowry method and Dubois method, respectively. Addition of 2 mg/L coagulant concentration did not affect SEPS proteins in comparison with control process and their values varied between 32 to 38mg/g VSS. However a coagulant dosage of 5mg/L resulted in a slight increase of SEPS proteins at 35-40 mg/g VSS while 10mg/L coagulant further increased SEPS to 44-48mg/g VSS. Similar results were obtained for SEPS carbohydrates. Carbohydrates values without coagulant addition were similar to the corresponding values measured for 2mg/L coagulant; the addition of mg/L coagulant resulted to a slight increase of carbohydrates SEPS to 6-7mg/g VSS while a dose of 10 mg/L further increased carbohydrates content to 9-10mg/g VSS. Total LBEPS and TBEPS, consisted of proteins and carbohydrates of LBEPS and TBEPS respectively, presented similar variations by the addition of the coagulant. Total LBEPS at 2mg/L dose were almost equal to 17mg/g VSS, and their values increased to 22 and 29 mg/g VSS during the addition of 5 mg/L and 10 mg/L of coagulant respectively. Total TBEPS were almost 37 mg/g VSS at a coagulant dose of 2 mg/L and increased to 42 and 51 mg/g VSS at 5 mg/L and 10 mg/L doses, respectively. Therefore, it can be concluded that coagulant addition could potentially affect microorganisms activities, excreting EPS in greater amounts. Nevertheless, EPS increase, mainly SEPS increase, resulted to a higher membrane fouling rate, as justified by the corresponding TMP increase rate. However, the addition of the coagulant, although affected the EPS content in the reactor mixed liquor, did not change the filtration process: an effluent of high quality was produced, with COD values as low as 20-30 mg/L.

Keywords: extracellular polymeric substances, MBR, membrane fouling, EPS

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Authors: Loren S. Bernal., Catalina Castillo, Carel E. Carvajal, José F. Ibla

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Plastic pollution, specifically microplastics, has become a significant issue in aquatic ecosystems worldwide. The large amount of plastic waste carried by water tributaries has resulted in the accumulation of microplastics in water bodies. The polymer aging process caused by environmental influences such as photodegradation and chemical degradation of additives leads to polymer embrittlement and properties change that require degradation or reduction procedures in rivers. However, there is a lack of such procedures for freshwater entities that develop over extended periods. The aim of this study is evaluate the potential of Pleurotus ostreatus a fungus, in reducing lowdensity polyethylene microplastics present in freshwater samples collected from the middle basin of the Magdalena River in Colombia. The study aims to evaluate this process both in vitro and in silico by identifying the growth capacity of Pleurotus ostreatus in the presence of microplastics and identifying the most likely interactions of Pleurotus ostreatus enzymes and their affinity energies. The study follows an engineering development methodology applied on an experimental basis. The in vitro evaluation protocol applied in this study focused on the growth capacity of Pleurotus ostreatus on microplastics using enzymatic inducers. In terms of in silico evaluation, molecular simulations were conducted using the Autodock 1.5.7 program to calculate interaction energies. The molecular dynamics were evaluated by using the myPresto Portal and GROMACS program to calculate radius of gyration and Energies.The results of the study showed that Pleurotus ostreatus has the potential to degrade low-density polyethylene microplastics. The in vitro evaluation revealed the adherence of Pleurotus ostreatus to LDPE using scanning electron microscopy. The best results were obtained with enzymatic inducers as a MnSO4 generating the activation of laccase or manganese peroxidase enzymes in the degradation process. The in silico modelling demonstrated that Pleurotus ostreatus was able to interact with the microplastics present in LDPE, showing affinity energies in molecular docking and molecular dynamics shown a minimum energy and the representative radius of gyration between each enzyme and its substract. The study contributes to the development of bioremediation processes for the removal of microplastics from freshwater sources using the fungus Pleurotus ostreatus. The in silico study provides insights into the affinity energies of Pleurotus ostreatus microplastic degrading enzymes and their interaction with low-density polyethylene. The study demonstrated that Pleurotus ostreatus can interact with LDPE microplastics, making it a good agent for the development of bioremediation processes that aid in the recovery of freshwater sources. The results of the study suggested that bioremediation could be a promising approach to reduce microplastics in freshwater systems.

Keywords: bioremediation, in silico modelling, microplastics, Pleurotus ostreatus

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Authors: Preshanthan Moodley

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This study compares two different pretreatments for sugarcane leaf waste (SLW): steam salt-alkali (SSA) and microwave salt-alkali (MSA). The two pretreatment types were modelled, optimized, and validated with R² > 0.97. Reducing sugar yields of 1.21g/g were obtained with optimized SSA pretreatment using 1.73M ZnCl₂, 1.36M NaOH and 9.69% solid loading, and 1.17g/g with optimized MSA pretreatment using 1.67M ZnCl₂, 1.52M NaOH at 400W for 10min. A lower pretreatment time (10min) was required for the MSA model (83% lower). The structure of pretreated SLW was assessed using scanning electron microscopy (SEM) and Fourier Transform Infrared analysis (FTIR). The optimized SSA and MSA models showed lignin removal of 80.5 and 73% respectively. The MSA pretreatment was further examined on sorghum leaves and Napier grass and showed yield improvements of 1.9- and 2.8-fold compared to recent reports. The developed pretreatment methods demonstrated high efficiency at enhancing enzymatic hydrolysis on various lignocellulosic substrates.

Keywords: lignocellulosic biomass, pretreatment, salt, sugarcane leaves

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Authors: Ahmad Manbohi, Seyyed Hamid Ahmadi

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A low-cost paper-based microfluidic device (PAD) for the multiplex electrochemical determination of glucose, uric acid, and dopamine in biological fluids was developed. Using wax printing, PAD containing a central zone, six channels, and six detection zones was fabricated, and the electrodes were printed on detection zones using pre-made electrodes template. For each analyte, two detection zones were used. The carbon working electrode was coated with chitosan-BSA (and enzymes for glucose and uric acid). To detect glucose and uric acid, enzymatic reactions were employed. These reactions involve enzyme-catalyzed redox reactions of the analytes and produce free electrons for electrochemical measurement. Calibration curves were linear (R^² > 0.980) in the range of 0-80 mM for glucose, 0.09–0.9 mM for dopamine, and 0–50 mM for uric acid, respectively. Blood samples were successfully analyzed by the proposed method.

Keywords: biological fluids, biomarkers, microfluidic paper-based electrochemical biosensors, Multiplex

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Authors: Neha Babbar, S. Van Roy, W. Dejonghe, S. Sforza, K. Elst

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Pectic oligosaccharides (a class of prebiotics) are non-digestible carbohydrates which benefits the host by stimulating the growth of healthy gut micro flora. Production of prebiotic pectic oligosaccharides (POS) from pectin rich agricultural residues involves a cutting of long chain polymer of pectin to oligomers of pectin while avoiding the formation of monosaccharides. The objective of the present study is to develop a two-step continuous biocatalytic membrane reactor (MER) for the continuous production of POS (from sugar beet pulp) in which conversion is combined with separation. Optimization of the ratio of POS/monosaccharides, stability and productivities of the process was done by testing various residence times (RT) in the reactor vessel with diluted (10 RT, 20 RT, and 30 RT) and undiluted (30 RT, 40 RT and 60 RT) substrate. The results show that the most stable processes (steady state) were 20 RT and 30 RT for diluted substrate and 40 RT and 60 RT for undiluted substrate. The highest volumetric and specific productivities of 20 g/L/h and 11 g/gE/h; 17 g/l/h and 9 g/gE/h were respectively obtained with 20 RT (diluted substrate) and 40 RT (undiluted substrate). Under these conditions, the permeates of the reactor test with 20 RT (diluted substrate) consisted of 80 % POS fractions while that of 40 RT (undiluted substrate) resulted in 70% POS fractions. A two-step continuous biocatalytic MER for the continuous POS production looks very promising for the continuous production of tailor made POS. Although both the processes i.e 20 RT (diluted substrate) and 40 RT (undiluted substrate) gave the best results, but for an Industrial application it is preferable to use an undiluted substrate.

Keywords: pectic oligosaccharides, membrane reactor, residence time, specific productivity, volumetric productivity

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Authors: Abirami Baleswaran, Christel Couderc, Loubnah Belahcen, Jean Dayde, Hélène Tormo, Gwénaëlle Jard

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Cheeses are often reported to be spoiled by Pseudomonas spp., responsible for defects in appearance, texture, taste, and smell, leading to their non-marketing and even their destruction. Despite preventive actions, problems linked to Pseudomonas spp. are difficult to control by the lack of knowledge and control of these contaminants during the cheese manufacturing. Lactic goat cheese producers are not spared by this problem and are looking for solutions to decrease the number of spoiled cheeses. To explore different hypotheses, experiments are needed. However, cheese-making experiments at the pilot scale are expensive and time consuming. Thus, there is a real need to develop a miniature cheeses model system under controlled conditions. In a previous study, several miniature cheese models corresponding to different type of commercial cheeses have been developed for different purposes. The models were, for example, used to study the influence of milk, starters cultures, pathogen inhibiting additives, enzymatic reactions, microflora, freezing process on cheese. Nevertheless, no miniature model was described on the lactic goat cheese. The aim of this work was to develop a miniature cheese model system under controlled laboratory conditions which resembles commercial lactic goat cheese to study Pseudomonas spp. spoilage during the manufacturing and ripening process. First, a protocol for the preparation of miniature cheeses (3.5 times smaller than a commercial one) was designed based on the cheese factorymanufacturing process. The process was adapted from “Rocamadour” technology and involves maturation of pasteurized milk, coagulation, removal of whey by centrifugation, moulding, and ripening in a little scale cellar. Microbiological (total bacterial count, yeast, molds) and physicochemical (pH, saltinmoisture, moisture in fat-free)analyses were performed on four key stages of the process (before salting, after salting, 1st day of ripening, and end of ripening). Factory and miniature cheeses volatilomewere also obtained after full scan Sift-MS cheese analysis. Then, Pseudomonas spp. strains isolated from contaminated cheeses were selected on their origin, their ability to produce pigments, and their enzymatic activities (proteolytic, lecithinasic, and lipolytic). Factory and miniature curds were inoculated by spotting selected strains on the cheese surface. The expression of cheese spoilage was evaluated by counting the level of Pseudomonas spp. during the ripening and by visual observation and under UVlamp. The physicochemical and microbiological compositions of miniature cheeses permitted to assess that miniature process resembles factory process. As expected, differences involatilomes were observed, probably due to the fact that miniature cheeses are made usingpasteurized milk to better control the microbiological conditions and also because the little format of cheese induced probably a difference during the ripening even if the humidity and temperature in the cellar were quite similar. The spoilage expression of Pseudomonas spp. was observed in miniature and factory cheeses. It confirms that the proposed model is suitable for the preparation of miniature cheese specimens in the spoilage study of Pseudomonas spp. in lactic cheeses. This kind of model could be deployed for other applications and other type of cheese.

Keywords: cheese, miniature, model, pseudomonas spp, spoilage

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Authors: Azad Khalid, Sifa Dogan

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Because of its persistence in conventional treatment plants and broad prevalence in water bodies, the pharmaceutical chemical carbamazepine (CBZ) has been suggested as an anthropogenic marker to evaluate water quality. This study provides a thorough examination of the origins and occurrences of CBZ in water bodies, as well as the drug's toxicological effects and laws. Given CBZ's well-documented negative consequences on the human body when used medicinally, cautious monitoring in water is advised. CBZ residues in drinking water may enter embryos and newborns via intrauterine exposure or breast-feeding, causing congenital abnormalities and/or neurodevelopmental issues over time. The insufficiency of solo solutions was shown after an in-depth technical study of traditional and sophisticated treatment technologies. Nanofiltration and reverse osmosis membranes are more successful at removing CBZ than traditional activated sludge and membrane bioreactor techniques. Recent research has shown that severe chemical cleaning, which is essential to prevent membrane fouling, may lower long-term removal efficiency. Furthermore, despite the efficacy of activated carbon adsorption and advanced oxidation processes, a few issues such as chemical cost and activated carbon renewal must be carefully examined. Individual technology constraints lead to the benefits of combined and hybrid systems, namely the heterogeneous advanced oxidation process.

Keywords: carbamazepine, occurrence, toxicity, conventical treatment, advanced oxidation process (AOPs)

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Authors: Rezvan Najafi, Korosh Heydari, Massoud Saidijam

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5-FU is a chemotherapeutic agent that has been used in colorectal cancer (CRC) treatment. However, it is usually associated with the acquired resistance, which decreases the therapeutic effects of 5-FU. miR-200c is involved in chemotherapeutic drug resistance, but its mechanism is not fully understood. In this study, the effect of inhibition of miR-200c in sensitivity of HCT-116 CRC cells to 5-FU was evaluated. HCT-116 cells were transfected with LNA-anti- miR-200c for 48 h. mRNA expression of miR-200c was evaluated using quantitative real- time PCR. The protein expression of phosphatase and tensin homolog (PTEN) and E-cadherin were analyzed by western blotting. Annexin V and propidium iodide staining assay were applied for apoptosis detection. The caspase-3 activation was evaluated by an enzymatic assay. The results showed LNA-anti-miR-200c inhibited the expression of PTEN and E-cadherin protein, apoptosis and activation of caspase 3 compared with control cells. In conclusion, these results suggest that miR-200c as a prognostic marker can overcome to 5-FU chemoresistance in CRC.

Keywords: colorectal cancer, miR-200c, 5-FU resistance, E-cadherin, PTEN

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Authors: Paweł Stączek, Tomasz Plech, Aleksandra Strzelczyk, Katarzyna Dzitko, Monika Wujec, Edyta Kuśmierz, Piotr Paneth, Agata Paneth

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In this contribution, we will describe the inhibitory potency of nine thiosemicarbazide derivatives against bacterial type IIA topoisomerases, their antibacterial profile, and molecular modeling evaluation. We have found that one of the tested compounds, 4-benzoyl-1-(2-methyl-furan-3-ylcarbonyl) thiosemicarbazide, remarkably inhibits the activity of S. aureus DNA gyrase with the IC50 below 5 μM. Besides, this compound displays antibacterial activity on Staphylococcus spp. and E. faecalis at non-cytotoxic concentrations in mammalian cells, with minimal inhibitory concentrations (MICs) values at 25 μg/mL. Based on the enzymatic and molecular modeling studies we propose two factors, i.e. geometry of molecule and hydrophobic/hydrophilic balance as important molecular properties for developing thiosemicarbazide derivatives as potent Staphylococcus aureus DNA gyrase inhibitors.

Keywords: bioactivity, drug design, topoisomerase, molecular modeling

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Authors: Shweta Kumari, Parmjit S. Panesar, Manab B. Bera

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The hydrolysis of lactose using β-galactosidase is one of the most promising biotechnological applications, which has wide range of potential applications in food processing industries. However, due to intracellular location of the yeast enzyme, and expensive extraction methods, the industrial applications of enzymatic hydrolysis processes are being hampered. The use of permeabilization technique can help to overcome the problems associated with enzyme extraction and purification of yeast cells and to develop the economically viable process for the utilization of whole cell biocatalysts in food industries. In the present investigation, standardization of permeabilization process of novel yeast isolate was carried out using a statistical model approach known as Response Surface Methodology (RSM) to achieve maximal b-galactosidase activity. The optimum operating conditions for permeabilization process for optimal β-galactosidase activity obtained by RSM were 1:1 ratio of toluene (25%, v/v) and ethanol (50%, v/v), 25.0 oC temperature and treatment time of 12 min, which displayed enzyme activity of 1.71 IU /mg DW.

Keywords: β-galactosidase, optimization, permeabilization, response surface methodology, yeast

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Authors: Abimbola M. Enitan, J. Adeyemo

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Anaerobic modeling is a useful tool to describe and simulate the condition and behaviour of anaerobic treatment units for better effluent quality and biogas generation. The present investigation deals with the anaerobic treatment of brewery wastewater with varying organic loads. The chemical oxygen demand (COD) and total suspended solids (TSS) of the influent and effluent of the bioreactor were determined at various retention times to generate data for kinetic coefficients. The bio-kinetic coefficients in the modified Stover–Kincannon kinetic and methane generation models were determined to study the performance of anaerobic digestion process. At steady-state, the determination of the kinetic coefficient (K), the endogenous decay coefficient (Kd), the maximum growth rate of microorganisms (µmax), the growth yield coefficient (Y), ultimate methane yield (Bo), maximum utilization rate constant Umax and the saturation constant (KB) in the model were calculated to be 0.046 g/g COD, 0.083 (dˉ¹), 0.117 (d-¹), 0.357 g/g, 0.516 (L CH4/gCODadded), 18.51 (g/L/day) and 13.64 (g/L/day) respectively. The outcome of this study will help in simulation of anaerobic model to predict usable methane and good effluent quality during the treatment of industrial wastewater. Thus, this will protect the environment, conserve natural resources, saves time and reduce cost incur by the industries for the discharge of untreated or partially treated wastewater. It will also contribute to a sustainable long-term clean development mechanism for the optimization of the methane produced from anaerobic degradation of waste in a close system.

Keywords: brewery wastewater, methane generation model, environment, anaerobic modeling

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Authors: Esma Kocaoglu, Oktay Talaz, Huseyin Cavdar, Murat Senturk, Deniz Eki̇nci̇

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Glutathione reductase (GR) is a crucial antioxidant enzyme which is responsible for the maintenance of the antioxidant GSH (glutathione) molecule. Antimalarial effects of some chemical molecules are attributed to their inhibition of GR; thus inhibitors of this enzyme are expected to be promising candidates for the treatment of malaria. In this work, GR inhibitory properties of N-Methylpyrrole derivatives are reported. Firstly, GR was purified by means of affinity chromatography using 2’,5’-ADP-Sepharose 4B as ligand. Enzymatic activity was measured by Beutler’s method. Synthesis of the compounds was approved by thin layer chromatography and column chromatography. Different inhibitor concentrations were used and all compounds were tested in triplicate at each concentration used. It was found that all compounds have better inhibitory activity than the strong GR inhibitor N,N-bis(2-chloroethyl)-N-nitrosourea, especially three molecules, 8m, 8n, and 8q, are the best among them with low micromolar I₅₀ values. Findings of our study indicate that these Schiff base derivatives are strong GR inhibitors which can be used as leads for designation of novel antimalaria candidates.

Keywords: glutathione reductase, antimalaria, inhibitor, enzyme

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Authors: Preshanthan Moodley, E. B. Gueguim-Kana

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The objective of this study was to develop a method to pretreat sugarcane leaf waste using microwave-assisted (MA) inorganic salt. The effects of process parameters of salt concentration, microwave power intensity and pretreatment time on reducing sugar yield from enzymatically hydrolysed sugarcane leaf waste were investigated. Pretreatment models based on MA-NaCl, MA-ZnCl2 and MA-FeCl3 were developed. Maximum reducing sugar yield of 0.406 g/g was obtained with 2 M FeCl3 at 700W for 3.5 min. Scanning electron microscopy (SEM) and Fourier Transform Infrared analysis (FTIR) showed major changes in lignocellulosic structure after MA-FeCl3 pretreatment with 71.5 % hemicellulose solubilization. This pretreatment was further assessed on sorghum leaves and Napier grass under optimal MA-FeCl3 conditions. A 2 fold and 3.1-fold increase in sugar yield respectively were observed compared to previous reports. This pretreatment was highly effective for enhancing enzymatic saccharification of lignocellulosic biomass.

Keywords: acid, pretreatment, salt, sugarcane leaves

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Authors: T. Bettaieb, S. Soufi, S. Arbaoui

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Stevia rebaudiana Bert. is a natural sweet plant. The leaves contain diterpene glycosides stevioside, rebaudiosides A-F, steviolbioside and dulcoside, which are responsible for its sweet taste and have commercial value all over the world as sugar substitute in foods and medicines. Stevia rebaudiana Bert. is sensitive temperature lower than 9°C. The possibility of its outdoor culture in Tunisian conditions demand genotypes tolerant to low temperatures. In order to evaluate the low temperature tolerance of eight genotypes of Stevia rebaudiana, the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalases (CAT) were measured. Before carrying out the analyses, three genotypes of Stevia were exposed for 1 month at a temperature regime of 18°C during the day and 7°C at night similar to winter conditions in Tunisia. In response to the stress generated by low temperature, antioxidant enzymes activity revealed on native gel and quantified by spectrophotometry showed variable levels according to their degree of tolerance to low temperatures.

Keywords: chilling tolerance, enzymatic activity, stevia rebaudiana bert, low thermal stress

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Authors: Deokyeong Choe, Keonwook Nam, Young Hoon Roh

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Wood waste is a potentially significant resource for economic and environment-friendly recycling. Wood waste represents a key sustainable source of biomass for transformation into bioethanol. Unfortunately, wood waste is highly recalcitrant for biotransformation, which limits its use and prevents economically viable conversion into bioethanol. As a result, an effective pretreatment is necessary to degrade cellulose of the wood waste, which improves the accessibility of cellulase. In this work, a H₃PO₄-acetone pretreatment was selected among the various pretreatment methods and used to dissolve cellulose and lignin. When the H₃PO₄ and acetone were used, 5–6% of the wood waste was found to be very appropriate for saccharification. Also, when the enzymatic saccharification was conducted in the mixture of the wood waste and 0.05 M citrate buffer solution, glucose and xylose were measured to be 80.2 g/L and 9.2 g/L respectively. Furthermore, ethanol obtained after 70 h of fermentation by S. cerevisiae was 30.4 g/L. As a result, the conversion yield from wood waste to bioethanol was calculated to be 57.4%. These results show that the pretreated wood waste can be used as good feedstocks for bioethanol production and that the H₃PO₄-acetone pretreatment can effectively increase the yield of ethanol production.

Keywords: wood waste, H₃PO₄-acetone, bioethanol, fermentation

Procedia PDF Downloads 546

Authors: Leyla Esfandiari

Abstract:

Rapid, sensitive detection of nucleic acid (NA) molecules of specific sequence is of interest for a range of diverse health-related applications such as screening for genetic diseases, detecting pathogenic microbes in food and water, and identifying biological warfare agents in homeland security. Sequence-specific nucleic acid detection platforms rely on base pairing interaction between two complementary single stranded NAs, which can be detected by the optical, mechanical, or electrochemical readout. However, many of the existing platforms require amplification by polymerase chain reaction (PCR), fluorescent or enzymatic labels, and expensive or bulky instrumentation. In an effort to address these shortcomings, our research is focused on utilizing the cutting edge nanotechnology and microfluidics along with resistive pulse electrical measurements to design and develop a cost-effective, handheld and highly-sensitive nanopore-based sensor for point-of-care medical diagnostics.

Keywords: diagnostics, nanopore, nucleic acids, sensor

Procedia PDF Downloads 437

Authors: Md Fazle Alam, Amaj Ahmed Laskar, Hina Younus

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Melamine toxicity which causes renal failure and death of humans and animals have recently attracted worldwide attention. Developing an easy, fast and sensitive method for the routine melamine detection is the need of the hour. Herein, we have developed a rapid, sensitive, one step and selective colorimetric method for the detection of melamine in milk samples based upon in-situ formation of silver nanoparticles (AgNPs) via tannic acid at room temperature. These AgNPs thus formed were characterized by UV-VIS spectrophotometer, transmission electron microscope (TEM), zetasizer and dynamic light scattering (DLS). Under optimal conditions, melamine could be selectively detected within the concentration range of 0.05-1.4 µM with a limit of detection (LOD) of 10.1 nM, which is lower than the strictest melamine safety requirement of 1 ppm. This assay does not utilize organic cosolvents, enzymatic reactions, light sensitive dye molecules and sophisticated instrumentation, thereby overcoming some of the limitations of conventional methods.

Keywords: milk adulteration, melamine, silver nanoparticles, tannic acid

Procedia PDF Downloads 231

Authors: A. H. Birniwa, A. A. Salisu, M. Y. Yakasai, A. Sabo, K. Aujara, A. Isma’il

Abstract:

Sisal fibre was extracted from Sisal leaves by enzymatic retting method. A portion of the fibre was subjected to treatment with alkali, benzoyl chloride and silane compounds. Sisal fibre composites were fabricated using unsaturated polyester resin, by hand lay-up technique using both the treated and untreated fibre. Tensile, flexural and water absorption tests were conducted and evaluated on the composites. The results obtained were found to increase in the treated fibre compared to untreated fibre. Surface morphology of the fibre was observed using scanning electron microscopy (SEM) and the result obtained showed variation in the morphology of the treated and untreated fibre. FT-IR results showed inclusion of benzoyl and silane groups on the fibre surface. The fibre chemical modification improves its adhesion to the matrix, mechanical properties of the composites were also found to improve.

Keywords: composite, flexural strength, matrix, sisal fibre

Procedia PDF Downloads 359

Authors: B. Atika, S. Lehmann, E. Wimmer

Abstract:

The defense strategy is very common in the insect world. Defensive substances play a wide variety of functions for beetles, such as repellents, toxicants, insecticides, and antimicrobics. Beetles react to predators, invaders, and parasitic microbes with the release of toxic and repellent substances. Defensive substances are directed against a large array of potential target organisms or may function for boiling bombardment or as surfactants. Usually, Coleoptera biosynthesize and store their defensive compounds in a complex secretory organ, known as odoriferous defensive stink glands. The red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae), uses these glands to produce antimicrobial p-benzoquinones and 1-alkenes. In the past, the morphology of stink gland has been studied in detail in tenebrionid beetles; however, very little is known about the genes that are involved in the production of gland secretion. In this study, we studied a subset of genes that are essential for the benzoquinone production in red flour beetle. In the first phase, we selected 74 potential candidate genes from a genome-wide RNA interference (RNAi) knockdown screen named 'iBeetle.' All these 74 candidate genes were functionally characterized by RNAi-mediated gene knockdown. Therefore, they were selected for a subsequent gas chromatography-mass spectrometry (GC-MS) analysis of secretion volatiles in respective RNAi knockdown glands. 33 of them were observed to alter the phenotype of stink gland. In the GC-MS analysis, 7 candidate genes were noted to display a strongly altered gland, in terms of secretion color and chemical composition, upon knockdown, showing their key role in the biosynthesis of gland secretion. Morphologically altered stink glands were found for odorant receptor and protein kinase superfamily. Subsequent GC-MS analysis of secretion volatiles revealed reduced benzoquinone levels in LIM domain, PDZ domain, PBP/GOBP family knockdowns and a complete lack of benzoquinones in the knockdown of sulfatase-modifying factor enzyme 1, sulfate transporter family. Based on stink gland transcriptome data, we analyzed the function of sulfatase-modifying factor enzyme 1 and sulfate transporter family via RNAi-mediated gene knockdowns, GC-MS, in situ hybridization, and enzymatic activity assays. Morphologically altered stink glands were noted in knockdown of both these genes. Furthermore, GC-MS analysis of secretion volatiles showed a complete lack of benzoquinones in the knockdown of these two genes. In situ hybridization showed that these two genes are expressed around the vesicle of certain subgroup of secretory stink gland cells. Enzymatic activity assays on stink gland tissue showed that these genes are involved in p-benzoquinone biosynthesis. These results suggest that sulfatase-modifying factor enzyme 1 and sulfate transporter family play a role specifically in benzoquinone biosynthesis in red flour beetles.

Keywords: Red Flour Beetle, defensive stink gland, benzoquinones, sulfate transporter, sulfatase-modifying factor enzyme 1

Procedia PDF Downloads 127

Authors: Stephen Rathinaraj Benjamin, Flavio Colmati Junior, Maria Izabel Florindo Guedes, Rosa Amalia Fireman Dutra

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A new enzymatic electrochemical biosensor based on multiwall carbon nanotubes and cerium oxide nanoparticles for the detection of rutin has been developed. The cerium oxide nanoparticles /HRP/ multiwall carbon nanotubes/ carbon paste electrode (HRP/ CeO2/MWCNTs/CPE) was prepared by ensuing addition of MWCNTs and HRP on the CPE, followed by the mixing with cerium oxide nanoparticles. Surface physical characteristics of the modified electrode and the electrochemical properties of the composite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), cylic voltammetry (CV), differential pulse voltammetry (DPV) and square wave voltammetry (SWV). The HRP/ CeO2/MWCNTs/CPE showed good selectivity, stability and reproducibility, which was further applied to detect rutin tablet and capsule samples with satisfactory results.

Keywords: cerium dioxide nanoparticles, horseradish peroxidase, multiwall carbon nanotubes, rutin

Procedia PDF Downloads 371

Authors: Sudha Summarwar, Jyotsana Pandey, Deepali Lall

Abstract:

The Malathion compound has the great tendency to be accumulated in the organs of the fishes both if it is present in traces or in higher amount in the aquatic environment. It has the tendency to be accumulated more in quantity in the organs directly exposed to it. The accumulation was found to be time and concentration dependent. The accumulation of malathion was maximum in gills and is the minimum in the brain. Effect of different sub-lethal concentrations (l/5th, l/l0th, l/15th, l/20th, and 1/25th fractions of 96 hr. LC50) of malathion compound on acid phosphatase (AcPase), alkaline phosphatase (AlPase), serum glutamic oxalacetic transaminase (SGOT) and Serum Glucose-6-Phosphatase (S-G-6-Pase), serum glutamic pyruvic transaminase (SGPT) in blood of Labeo rohita exposed for the period of 15. 30, 45, and 60 days, have been studied in present investigations. In general the alterations were concentrations and duration dependent.

Keywords: AcPase, AlPase, Labeo rohita, malathion, S-G-6-Pase, SGOT, SGPT

Procedia PDF Downloads 301

Authors: Agustine Melviana, Rizkita Esyanti

Abstract:

Stevia plant contains steviol glycosides which is estimated to be 300 times sweeter than sucrose. However in Indonesia, conventional (in vivo) propagation of Stevia rebaudiana was not effective due to a poor result. Therefore, alternative methods to propagate S. rebaudiana plants is needed, one of it is using in vitro method. Multiplication with a large quantity of stevia biomass in relatively short period can be conducted by using TIS RITA® (Recipient for Automated Temporary Immersion System). The objective of this study was to evaluate the effect of immersion period of the medium on growth and the medium bioconversion into the production of shoot biomass. The study was conducted to determine the effect of different intensity period of medium to enhance biomass of stevia shoots. Shoot culture of S. rebaudiana was grown in full strength MS medium supplemented with 1 ppm Kinetin. RITA® bioreactors were set up with two different immersion periods, 15 min (RITA® 15) and 30 min (RITA® 30), scheduled every 6 hours and incubated for 21 days. The result indicated that immersion period affected the biomass and growth rate (µ). Thirty-minutes immersion showed greater percentage of shoot multiplication (93.44 ± 0.83%), percentage of leaf growth (85.24 ± 5.99%), growth rate (0.042 ± 0.001 g/day), and productivity (0.066 g/L medium/day) compared to that immersed in RITA® 15 min (76.90 ± 4.85%; 79.73 ± 7.76; 0.045 ± 0.004 g/day, and 0.045 g/L medium/day respectively). Enhancement of biomass in RITA® 30 reached 1,702 ± 0,114 gr, whereas in RITA® 15 only 0,953 ± 0,093 gr. Additionally, the pattern of sucrose, mineral, and inorganic compounds consumption followed the growth of plant biomass for both systems. In conclusion, the bioconversion efficiency from medium to biomass in RITA® 30 is better than RITA® 15.

Keywords: intensity period, shoot culture, Stevia rebaudiana, TIS RITA®

Procedia PDF Downloads 230

Authors: Maxim Panov, Evgenia Khairullina, Sergey Ermakov, Oleg Gundobin, Vladimir Kochemirovsky

Abstract:

The continuous in situ laser-induced catalysis proceeding via generation and growth of nano-sized copper particles was discussed. Also, the simple and lost-cost method for manufacturing of microstructural copper electrodes was proposed. The electrochemical properties of these electrodes were studied by cyclic voltammetry and impedance spectroscopy. The surface of the deposited copper structures (electrodes) was investigated by X-ray photoelectron spectroscopy and atomic force microscopy. These microstructures are highly conductive and porous with a dispersion of pore size ranging from 50 nm to 50 μm. An analytical response of the fabricated copper electrode is 30 times higher than those observed for a pure bulk copper with similar geometric parameters. A study of sensory characteristics for hydrogen peroxide determination showed that the value of Faraday current at the fabricated copper electrode is 2-2.5 orders of magnitude higher than for etalon one.

Keywords: laser-induced deposition, electrochemical electrodes, non-enzymatic sensors, copper

Procedia PDF Downloads 217