Showing papers in "Applied Biochemistry and Biotechnology in 2015"

A Comprehensive Review of Aliphatic Hydrocarbon Biodegradation by Bacteria

Abstract: Hydrocarbons are relatively recalcitrant compounds and are classified as high-priority pollutants. However, these compounds are slowly degraded by a large variety of microorganisms. Bacteria are able to degrade aliphatic saturated and unsaturated hydrocarbons via both aerobic and anaerobic pathways. Branched hydrocarbons and cyclic hydrocarbons are also degraded by bacteria. The aerobic bacteria use different types of oxygenases, including monooxygenase, cytochrome-dependent oxygenase and dioxygenase, to insert one or two atoms of oxygen into their targets. Anaerobic bacteria, on the other hand, employ a variety of simple organic and inorganic molecules, including sulphate, nitrate, carbonate and metals, for hydrocarbon oxidation.

Biosensor Technology for Pesticides—A review

Abstract: Pesticides, due to their lucrative outcomes, are majorly implicated in agricultural fields for crop production enhancement. Due to their pest removal properties, pesticides of various classes have been designed to persist in the environment over a longer duration after their application to achieve maximum effectiveness. Apart from their recalcitrant structure and agricultural benefits, pesticides also impose acute toxicological effects onto the other various life forms. Their accumulation in the living system may prove to be detrimental if established in higher concentrations. Thus, their prompt and accurate analysis is a crucial matter of concern. Conventional techniques like chromatographic techniques (HPLC, GC, etc.) used for pesticides detection are associated with various limitations like stumpy sensitivity and efficiency, time consumption, laboriousity, requirement of expensive equipments and highly trained technicians, and many more. So there is a need to recruit the methods which can detect these neurotoxic compounds sensitively, selectively, rapidly, and easily in the field. Present work is a brief review of the pesticide effects, their current usage scenario, permissible limits in various food stuffs and 21st century advancements of biosensor technology for pesticide detection. Due to their exceptional performance capabilities, easiness in operation and on-site working, numerous biosensors have been developed for bio-monitoring of various environmental samples for pesticide evaluation immensely throughout the globe. Till date, based on sensing element (enzyme based, antibody based, etc.) and type of detection method used (Electrochemical, optical, and piezoelectric, etc.), a number of biosensors have been developed for pesticide detection. In present communication, authors have summarized 21st century's approaches of biosensor technology for pesticide detection such as enzyme-based biosensors, immunosensors, aptamers, molecularly imprinted polymers, and biochips technology. Also, the major technological advancements of nanotechnology in the field of biosensor technology are discussed. Various biosensors mentioned in manuscript are found to exhibit storage stability of biocomponent ranging from 30-60 days, detection limit of 10(-6) - 10(-16) M, response time of 1-20 min and applications of developed biosensors in environmental samples (water, food, vegetables, milk, and juice samples, etc.) are also discussed. Researchers all over the globe are working towards the development of different biosensing techniques based on contrast approaches for the detection of pesticides in various environmental samples.

A Simple Green Synthesis of Palladium Nanoparticles with Sargassum Alga and Their Electrocatalytic Activities Towards Hydrogen Peroxide.

Abstract: This study presents the synthesis of palladium nanoparticles (PdNPs) using the extract derived from the marine alga, Sargassum bovinum, collected from Persian Gulf area. Water-soluble compounds that exist in the marine alga extract were the main cause of the reduction of palladium ions to Pd nanoparticles. The basic properties of PdNPs produced in this method were confirmed by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) analysis, and Fourier transform infrared spectroscopy (FTIR). TEM confirmed the monodispersed and octahedral shape of PdNPs within the size ranges from 5 to 10 nm. Catalytic performance of the biosynthetic PdNPs was investigated by electrochemical reduction of hydrogen peroxide (H2O2). PdNP-modified carbon ionic liquid electrode (PdNPs/CILE) was developed as a nonenzymatic sensor for the determination of hydrogen peroxide. Amperometric measurements showed that PdNPs/CILE is a reliable sensor for the detection of hydrogen peroxide in the range of 5.0 μM-15.0 mM with a sensitivity of 284.35 mAmM(-1) cm(-2) and a detection limit of 1.0 μM. Moreover, PdNPs/CILE exhibits a wide linear range, high sensitivity and selectivity, and excellent stability for the detection of H2O2 in aqueous solutions.

A Review: Potential Usage of Cellulose Nanofibers (CNF) for Enzyme Immobilization via Covalent Interactions

Abstract: Nanobiocatalysis is a new frontier of emerging nanosized material support in enzyme immobilization application. This paper is about a comprehensive review on cellulose nanofibers (CNF), including their structure, surface modification, chemical coupling for enzyme immobilization, and potential applications. The CNF surface consists of mainly -OH functional group that can be directly interacted weakly with enzyme, and its binding can be improved by surface modification and interaction of chemical coupling that forms a strong and stable covalent immobilization of enzyme. The knowledge of covalent interaction for enzyme immobilization is important to provide more efficient interaction between CNF support and enzyme molecule. Enzyme immobilization onto CNF is having potential for improving enzymatic performance and production yield, as well as contributing toward green technology and sustainable sources.

Simultaneous Heterotrophic Nitrification and Aerobic Denitrification by the Marine Origin Bacterium Pseudomonas sp. ADN-42

Abstract: Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment.

Enhanced Biological Straw Saccharification Through Coculturing of Lignocellulose-Degrading Microorganisms

Abstract: Lignocellulosic waste (LCW) is an abundant, low-cost, and inedible substrate for the induction of lignocellulolytic enzymes for cellulosic bioethanol production using an efficient, environmentally friendly, and economical biological approach. In this study, 30 different lignocellulose-degrading bacterial and 18 fungal isolates were quantitatively screened individually for the saccharification of four different ball-milled straw substrates: wheat, rice, sugarcane, and pea straw. Rice and sugarcane straws which had similar Fourier transform-infrared spectroscopy profiles were more degradable, and resulted in more hydrolytic enzyme production than wheat and pea straws. Crude enzyme produced on native straws performed better than those on artificial substrates (such as cellulose and xylan). Four fungal and five bacterial isolates were selected (based on their high strawase activities) for constructing dual and triple microbial combinations to investigate microbial synergistic effects on saccharification. Combinations such as FUNG16-FUNG17 (Neosartorya fischeri-Myceliophthora thermophila) and RMIT10-RMIT11 (Aeromonas hydrophila-Pseudomonas poae) enhanced saccharification (3- and 6.6-folds, respectively) compared with their monocultures indicating the beneficial effects of synergism between those isolates. Dual isolate combinations were more efficient at straw saccharification than triple combinations in both bacterial and fungal assays. Overall, co-culturing can result in significant increases in saccharification which may offer significant commercial potential for the use of microbial consortia.

Cyanobacterial Sunscreen Scytonemin: Role in Photoprotection and Biomedical Research

Abstract: Cyanobacteria are the most promising group of photosynthetic microorganisms capable of producing an array of natural products of industrial importance. Scytonemin is a small hydrophobic alkaloid pigment molecules present in the extracellular sheath of several cyanobacteria as a protective mechanism against short wavelength solar ultraviolet (UV) radiation. It has great efficacy to minimize the production of reactive oxygen species and formation of DNA lesions. The biosynthesis of scytonemin is regulated by different physico-chemical stressors. Scytonemin display multiple roles, functioning as a potent UV sunscreen and antioxidant molecules, and can be exploited in cosmetic and other industries for the development of new cosmeceuticals. Herein, we review the occurrence, biosynthesis, and potential application of scytonemin in photoprotection, pharmaceuticals, and biomedical research.

A Comparison of Polysaccharide Substrates and Reducing Sugar Methods for the Measurement of endo-1,4-β-Xylanase.

Abstract: The most commonly used method for the measurement of the level of endo-xylanase in commercial enzyme preparations is the 3,5-dinitrosalicylic acid (DNS) reducing sugar method with birchwood xylan as substrate. It is well known that with the DNS method, much higher enzyme activity values are obtained than with the Nelson-Somogyi (NS) reducing sugar method. In this paper, we have compared the DNS and NS reducing sugar assays using a range of xylan-type substrates and accurately compared the molar response factors for xylose and a range of xylo-oligosaccharides. Purified beechwood xylan or wheat arabinoxylan is shown to be a suitable replacement for birchwood xylan which is no longer commercially available, and it is clearly demonstrated that the DNS method grossly overestimates endo-xylanase activity. Unlike the DNS assay, the NS assay gave the equivalent colour response with equimolar amounts of xylose, xylobiose, xylotriose and xylotetraose demonstrating that it accurately measures the quantity of glycosidic bonds cleaved by the endo-xylanase. The authors strongly recommend cessation of the use of the DNS assay for measurement of endo-xylanase due to the fact that the values obtained are grossly overestimated due to secondary reactions in colour development.

Biogenic-Production of SnO2 Nanoparticles and Its Cytotoxic Effect Against Hepatocellular Carcinoma Cell Line (HepG2)

Abstract: In this paper, we have established for the first time, the terrific efficiency of aqueous extract of agricultural waste dried peel of sugar apple (Annona squamosa) in the rapid synthesis of stable SnO2 nanoparticles. In topical years, the deployment of secondary metabolites from plant extract has emerged as a novel technology for the synthesis of various nanoparticles. In this paper, we have studied the potential of SnO2 nanoparticles assembly using agricultural waste source for the first time. The synthesized nanoparticles were characterized and confirmed as SnO2 nanoparticles by using UV-visible spectroscopy, XRD, and TEM analysis. The motivation of this study was to examine cytotoxicity study of SnO2 nanoparticles against hepatocellular carcinoma cell line (HepG2). SnO2 nanoparticles inhibited the cell proliferation in a dose- and time-dependent manner with an IC50 value of 148 μg/mL. The treated cells showed an altered morphology with increasing concentrations of SnO2 nanoparticles. Our result shows that the SnO2 nanoparticles exhibit moderate cytotoxicity towards the hepatocellular carcinoma (HepG2) at tested concentrations.

Electrospun Polycaprolactone Membrane Incorporated with Biosynthesized Silver Nanoparticles as Effective Wound Dressing Material

Abstract: Biosynthesized silver nanoparticles (AgNPs) incorporated polycaprolactone (PCL) nanomembrane was prepared by electrospinning as a cost-effective nanocomposite for application as an antimicrobial agent against wound infection. The nanocomposite membrane was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis and Scanning Electron microscopy (SEM). The hydrophilicity analysis of electrospun membranes as evaluated by water contact angle measurement showed the change of hydrophobicity of PCL to hydrophilic upon incorporation of silver nanoparticles. Better mechanical properties were also observed for PCL membrane due to the incorporation of silver nanoparticles and are highly supportive to explore its biomedical applications. Further antibacterial analysis of silver nanoparticle-incorporated PCL membrane against common wound pathogens coagulase-negative Staphylococcus epidermidis and Staphylococcus haemolyticus showed remarkable activity. As biosynthesized AgNPs are least explored for clinical applications, the current study is a promising cost-effective method to explore the development of silver nanoparticle-based electrospun nanocomposite to resist wound-associated infection.

Overview of Antioxidant Peptides Derived from Marine Resources: The Sources, Characteristic, Purification, and Evaluation Methods.

Abstract: Marine organisms are rich sources of structurally diverse bioactive nitrogenous components. In recent years, numerous bioactive peptides have been identified in a range of marine protein resources, such as antioxidant peptides. Many studies have approved that marine antioxidant peptides have a positive effect on human health and the food industry. Antioxidant activity of peptides can be attributed to free radicals scavenging, inhibition of lipid peroxidation, and metal ion chelating. Moreover, it has also been verified that peptide structure and its amino acid sequence can mainly affect its antioxidant properties. The aim of this review is to summarize kinds of antioxidant peptides from various marine resources. Additionally, the relationship between structure and antioxidant activities of peptides is discussed in this paper. Finally, current technologies used in the preparation, purification, and evaluation of marine-derived antioxidant peptides are also reviewed.

Microwave-Assisted Extraction of Phycobiliproteins from Porphyridium purpureum

Abstract: In the present study, microwave-assisted extraction was first employed to extract the phycobiliproteins of Porphyridium purpureum (Pp). Freeze-dried Pp cells were subjected to microwave-assisted extraction (MAE) to extract phycoerythin (PE), phycocyanin (PC), and allophycocyanin (APC). MAE combined reproducibility and high extraction yields and allowed a 180- to 1,080-fold reduction of the extraction time compared to a conventional soaking process. The maximal PE extraction yield was obtained after 10-s MAE at 40 °C, and PE was thermally damaged at temperatures higher than 40 °C. In contrast, a flash irradiation for 10 s at 100 °C was the best process to efficiently extract PC and APC, as it combined a high temperature necessary to extract them from the thylakoid membrane to a short exposure to thermal denaturation. The extraction order of the three phycobiliproteins was coherent with the structure of Pp phycobilisomes. Moreover, the absorption and fluorescence properties of MAE extracted phycobiliproteins were stable for several months after the microwave treatment. Scanning electron microscopy indicated that MAE at 100 °C induced major changes in the Pp cell morphology, including fusion of the exopolysaccharidic cell walls and cytoplasmic membranes of adjacent cells. As a conclusion, MAE is a fast and high yield process efficient to extract and pre-purify phycobiliproteins, even from microalgae containing a thick exopolysaccharidic cell wall.

Cytotoxic and Genotoxic Effects of Titanium Dioxide Nanoparticles in Testicular Cells of Male Wistar Rat

Abstract: Serious concerns have been expressed about potential risks of engineered nanoparticles. Regulatory health risk assessment of such particles has become mandatory for the safe use in consumer products and medicines; also, the potential effects on reproduction and fertility are relevant for this risk evaluation. In the present study, we examined the effects of intravenously injected titanium dioxide nanoparticles (TiO2-NPs; 21 nm), with special emphasis on reproductive system. Antioxidant enzymes such as catalase, glutathione peroxidase, and superoxide dismutase showed a significant decrease, while significant increase in lipid peroxidase was observed. Our results confirmed the bioaccumulation of TiO2-NPs in testicular cells. In TiO2-NPs-treated animals, various functional and pathological disorders, such as reduced sperm count, increase in caspase-3 (a biomarker of apoptosis), creatine kinase activity, DNA damage, and cell apoptosis were observed. Moreover, the testosterone activity was decreased significantly in a dose-dependent manner in the animals treated with TiO2-NPs as compared with control group animals. It is concluded that TiO2-NPs induce oxidative stress, which produce cytotoxic and genotoxic changes in sperms which may affect the fertilizing potential of spermatozoa.

Nitrate starvation induced changes in root system architecture, carbon:nitrogen metabolism, and miRNA expression in nitrogen-responsive wheat genotypes.

Abstract: Improvement of nutrient use efficiency in cereal crops is highly essential not only to reduce the cost of cultivation but also to save the environmental pollution, reduce energy consumption for production of these chemical fertilizers, improve soil health, and ultimately help in mitigating climate change. In the present investigation, we have studied the morphological (with special emphasis on root system architecture) and biochemical responses (in terms of assay of the key enzymes involved in N assimilation) of two N-responsive wheat genotypes, at the seedling stage, under nitrate-optimum and nitrate-starved conditions grown in hydroponics. Expression profile of a few known wheat micro RNAs (miRNAs) was also studied in the root tissue. Total root size, primary root length, and first- and second-order lateral root numbers responded significantly under nitrate-starved condition. Morphological parameters in terms of root and shoot length and fresh and dry weight of roots and shoots have also been observed to be significant between N-optimum and N-starved condition for each genotypes. Nitrate reductase (NR), glutamine synthatase (GS), and glutamate dehydrogenase (GDH) activity significantly decreased under N-starved condition. Glutamine oxoglutarate amino transferase (GOGAT) and pyruvate kinase (PK) activity was found to be genotype dependent. Most of the selected miRNAs were expressed in root tissues, and some of them showed their differential N-responsive expression. Our studies indicate that one of the N-responsive genotype (NP-890) did not get affected significantly under nitrogen starvation at seedling stage.

Differential Activity and Expression Profile of Antioxidant Enzymes and Physiological Changes in Wheat (Triticum aestivum L.) Under Drought

Abstract: Wheat crop may experience water deficit at crucial stages during its life cycle, which induces oxidative stress in the plants The antioxidant status of the plant plays an important role in providing tolerance against the water stress The objective of this study was to investigate the impact of water stress on physiological traits, antioxidant activity and transcript profile of antioxidant enzyme related genes in four wheat genotypes (C306, AKAW3717, HD2687, PBW343) at three crucial stages of plants under medium (75% of field capacity) and severe stress (45% of field capacity) in pots Drought was applied by withholding water for 10 days at a particular growth stage viz tillering, anthesis and 15 days after anthesis (15DAA) For physiological traits, a highly significant effect of water stress at a particular stage and genotypic variations for resistance to drought tolerance was observed Under severe water stress, the malondialdehyde (MDA) content increased while the relative water content (RWC) and chlorophyll index decreased significantly in all the genotypes The drought susceptibility index (DSI) of the genotypes varied from 018 to 19 The drought treatment at the tillering and anthesis stages was found more sensitive in terms of reduction in thousand grain weight (TGW) and grain yield Antioxidant enzyme activities [superoxide dismutase (SOD) and peroxidase (POX)] increased with the decrease in osmotic potential in drought tolerant genotypes C306 and AKAW3717 Moreover, the transcript profile of Mn-SOD upregulated significantly and was consistent with the trend of the variation in SOD activity, which suggests that Mn-SOD might play an important role in drought tolerance

Probing of the interaction between β-lactoglobulin and the anticancer drug oxaliplatin.

Abstract: The potential carrier role of β-lactoglobulin (β-LG) and its interactions with oxaliplatin were studied using various spectroscopic techniques (fluorescence, UV-visible, and circular dichroism (CD)) in an aqueous medium at two temperatures of 25 and 37 °C in combination with a molecular docking study. Fluorescence measurements have shown that the observed quenching is a combination of static and dynamic quenching with a predominant contribution of static mode. The presence of a single binding site located in the internal cavity of the β-barrel of β-LG was confirmed by molecular docking calculations. Thermodynamic data as well as molecular docking indicated that the hydrophobic interactions dominate in the binding site. Results of fluorescence resonance energy transfer (FRET) measurements in combination with docking results imply that resonance energy transfer occurs between β-LG and its ligand oxaliplatin. Additionally, CD results revealed that oxaliplatin binding has no influence on the β-LG structure. The molecular docking results indicate that docking may be an appropriate method for the prediction and confirmation of experimental results. Complementary molecular docking results may be useful for the determination of the binding mechanism of proteins such as β-LG in pharmaceutical and biophysical studies providing new insight in the novel pharmacology and new solutions in the formulation of advanced oral drug delivery systems.

Biomass Yield and Steviol Glycoside Production in Callus and Suspension Culture of Stevia rebaudiana Treated with Proline and Polyethylene Glycol.

Abstract: Enhanced production of steviol glycosides (SGs) was observed in callus and suspension culture of Stevia rebaudiana treated with proline and polyethylene glycol (PEG). To study their effect, yellow-green and compact calli obtained from in vitro raised Stevia leaves were sub-cultured on MS medium supplemented with 2.0 mg l−1 NAA and different concentrations of proline (2.5–10 mM) and PEG (2.5–10 %) for 2 weeks, and incubated at 24 ± 1 °C and 22.4 μmol m−2 s−1 light intensity provided by white fluorescent tubes for 16 h. Callus and suspension culture biomass (i.e. both fresh and dry weight content) was increased with 5 mM proline and 5 % PEG, while at further higher concentrations, they got reduced. Further, quantification of SGs content in callus (collected at 15th day) and suspension culture (collected at 10th and 15th day) treated with and without elicitors was analysed by HPLC. It was observed that chemical stress enhanced the production of SGs significantly. In callus, the content of SGs increased from 0.27 (control) to 1.09 and 1.83 % with 7.5 mM proline and 5 % PEG, respectively, which was about 4.0 and 7.0 times higher than control. However, in the case of suspension culture, the same concentrations of proline and polyethylene glycol enhanced the SG content from 1.36 (control) to 5.03 and 6.38 %, respectively, on 10th day which were 3.7 times and 4.7 times higher than control.

Characterization of Bacillus spp. from the gastrointestinal tract of Labeo rohita--towards to identify novel probiotics against fish pathogens.

Abstract: The aim of the present study is to screen and characterize endogenous microbiota Bacillus spp. from the gastrointestinal (GI) tract of Labeo rohita in order to evaluate their probiotic attributes. A total of 74 isolates from the GI of L. rohita were evaluated for their antimicrobial properties by agar well-diffusion method against fish pathogens. Based on the better antibacterial features, three isolates (KADR1, KADR3, and KADR4) were selected for further delineation. The three selected isolates exhibited higher tolerance to bile salt, moderate tolerance to low pH, high surface hydrophobicity to solvents, and capable to autoaggregate. All three isolates demonstrated notable proteolytic, catalase activity and susceptibility to various antibiotics. Partial 16S rRNA sequencing revealed that the isolates exhibited 99 % sequence homology with Bacillus subtilis, Bacillus aerophilus, and Bacillus firmus of the database substantiating morphological and physiological characterization. Survivability in low pH and bile salt ensures their adaptability in the fish intestinal microenvironment. The ability to autoaggregate reveals colonization potential in the GI of the fish. Absence of hemolytic activity, antibiotic susceptibility to certain antibiotics, presence of protease and catalase activity, and non-pathogenic caliber of the above-mentioned isolates could be feasible characteristics when considering them as probiotics in the aquaculture industry.

Characterization and Application of Biosurfactant Produced by Bacillus licheniformis R2

Abstract: The biosurfactant produced by Bacillus licheniformis R2 was characterized and studied for enhancing the heavy crude oil recovery at 80 °C in coreflood experiments. The strain was found to be nonpathogenic and produced biosurfactant, reducing the surface tension of medium from 70 to 28 mN/m with 1.1 g/l yield. The biosurfactant was quite stable during exposure to elevated temperatures (85 °C for 90 days), high salinity (10 % NaCl), and a wide range of pH (5–12) for 10 days. It was characterized as lipopeptide similar to lichenysin-A, with a critical micelle concentration of about 19.4 mg/l. The efficiency of crude biosurfactant for enhanced oil recovery by core flood studies revealed it to recovering additional 37.1 % oil from Berea sandstone cores at 80 °C. The results are indicative of the potential for the development of lipopeptide biosurfactant-based ex situ microbial enhanced heavy oil recovery from depleting oil fields with extreme temperatures.

A comprehensive study on Chlorella pyrenoidosa for phenol degradation and its potential applicability as biodiesel feedstock and animal feed.

Abstract: The present work evaluates the phenol degradative performance of microalgae Chlorella pyrenoidosa. High-performance liquid chromatography (HPLC) analysis showed that C. pyrenoidosa degrades phenol completely up to 200 mg/l. It could also metabolize phenol in refinery wastewater. Biokinetic parameters obtained are the following: growth kinetics, μ max (media) > μ max (refinery wastewater), K s(media) < K s(refinery wastewater), K I(media) > K I(refinery wastewater); degradation kinetics, q max (media) > q max (refinery wastewater), K s(media) < K s(refinery wastewater), K I(media) > K I(refinery wastewater). The microalgae could cometabolize the alkane components present in refinery wastewater. Fourier transform infrared (FTIR) fingerprinting of biomass indicates intercellular phenol uptake and breakdown into its intermediates. Phenol was metabolized as an organic carbon source leading to higher specific growth rate of biomass. Phenol degradation pathway was elucidated using HPLC, liquid chromatography–mass spectrometry (LC-MS) and ultraviolet–visible (UV–visible) spectrophotometry. It involved both ortho- and meta-pathway with prominence of ortho-pathway. SEM analysis shows that cell membrane gets wrinkled on phenol exposure. Phenol degradation was growth and photodependent. Infrared analysis shows increased intracellular accumulation of neutral lipids opening possibility for utilization of spent biomass as biodiesel feedstock. The biomass after lipid extraction could be used as protein supplement in animal feed owing to enhanced protein content. The phenol remediation ability coupled with potential applicability of the spent biomass as biofuel feedstock and animal feed makes it a potential candidate for an environmentally sustainable process.

Enhanced Enzymatic Hydrolysis of Waste Paper for Ethanol Production Using Separate Saccharification and Fermentation

Abstract: Ethanol produced from lignocellulosic biomass is a renewable alternative to diminishing petroleum-based liquid fuels. In this study, the feasibility of ethanol production from waste paper using the separate hydrolysis and fermentation (SHF) was investigated. Two types of waste paper materials, newspaper and office paper, were evaluated for their potential to be used as a renewable feedstock for the production of fermentable sugars via enzymatic hydrolysis of their cellulose fractions. Hydrolysis step was conducted with a mixture of cellulolytic enzymes produced locally by Trichoderma reesei Rut-C30 (cellulase-overproducing mutant) and Aspergillus niger F38 cultures. Surfactant pretreatment effect on waste paper enzymatic digestibility was studied and Triton X-100 at 0.5 % (w w−1) has improved the digestibility of newspaper about 45 %. The effects of three factors (dry matter quantity, phosphoric acid pretreatment and hydrolysis time) on the extent of saccharification were also assessed and quantified by using a methodical approach based on response surface methodology. Under optimal hydrolysis conditions, maximum degrees of saccharification of newspaper and office paper were 67 and 92 %, respectively. Sugars released from waste paper were subsequently converted into ethanol (0.38 g ethanol g−1 sugar) with Saccharomyces cerevisiae CTM-30101.

Improving cell growth and lipid accumulation in green microalgae Chlorella sp. via UV irradiation.

Abstract: Microalgae with high biomass and high lipid content are the ideal feedstock for biodiesel production. To obtain such microalgae, ultraviolet (UV) irradiation was applied to Chlorella sp. to induce mutagenesis. The growth characteristics, total nitrogen (TN), and biochemical compositions of the control and UV mutation strains were analyzed. Compared to the control strain, the biomass for the UV mutation strain was 7.6 % higher and it presented a higher growth rate. The lipid content of the UV mutation strain showed different levels of increase and reached the maximum value of 28.1 % on day 15. Furthermore, the lipid productivity of the UV mutation strain showed a desired increase. The nitrogen consumption and Acetyl-CoA carboxylase (ACC) activity contributed to the lipid production by UV. All these results indicate that UV mutagenesis is an efficient method to improve probability for using Chlorella sp. as the potential raw material for biodiesel production.

Antioxidant Potential and Toxicity Study of the Cerium Oxide Nanoparticles Synthesized by Microwave-Mediated Synthesis

Abstract: Monodispersed cerium oxide nanoparticle has been synthesized by microwave-mediated hydrothermal as well as microwave-mediated solvothermal synthesis. X-ray diffraction (XRD) data shows that the synthesized particles are single phase. SEM and TEM analysis suggest that particle synthesized by microwave-mediated solvothermal method are less agglomerated. In vitro toxicology study of the synthesized nanoceria particles has shown good free radical scavenging activity for NO and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assayed except superoxide radical within a concentration range of 25 to 75 ng ml−1. Nanoceria particle also showed inhibition of Fe-ascorbate-induced lipid peroxidation (LPx) in chick liver mitochondrial fractions. Solvothermally synthesized nanoceria showed better protection against Fe-ascorbate-induced LPx than the hydrothermal one while the hydrothermally synthesized nanoceria showed better DPPH and NO scavenging activity. The ceria nanoparticles also prevented Fe-ascorbate-H2O2-induced carbonylation of bovine serum albumin in a dose-dependent manner. At higher concentration, i.e., 100 ng ml−1, the synthesized nanoparticles showed a reverse trend in all the parameters measured indicating its toxicity at higher doses.

2-Acetyl-1-pyrroline augmentation in scented indica rice (Oryza sativa L.) varieties through Δ(1)-pyrroline-5-carboxylate synthetase (P5CS) gene transformation.

Abstract: 2-Acetyl-1-pyrroline (2AP) has been identified as a principal aroma compound in scented rice varieties. Δ(1)-Pyrroline-5-carboxylate synthetase (P5CS) gene is reported to regulate the proline synthesis in plants and acts as the precursor of 2AP. Two scented indica rice varieties, namely Ambemohar 157 and Indrayani, were subjected to Agrobacterium tumefaciens-mediated genetic transformation containing P5CS gene. Overexpression of P5CS led to a significant increase in proline, P5CS enzyme activity and 2AP levels in transgenic calli, vegetative plant parts, and seeds over control in both the varieties. 2AP level increased more than twofold in transgenic seeds in both varieties. This is the first report of enhancement in 2AP content through overexpression of using P5CS gene, indicating the role of proline as a precursor amino acid in the biosynthesis of 2AP in scented rice.

Metabolomic Analysis Using Liquid Chromatography/Mass Spectrometry for Gastric Cancer

Abstract: Metabolomics is a post-genomics research field for analysis of low molecular weight compounds in biological samples and has shown great potentials for elucidating complex mechanisms associated with diseases. However, metabolomics studies on gastric cancer (GC), which is the second leading cause of cancer death worldwide, remain scarce, and the molecular mechanisms to metabolomics phenotypes are also still not fully understood. This study reports that the metabolic pathways can be exploited as biomarkers for diagnosis and treatment of GC progression as a case study. Importantly, the urinary metabolites and metabolic patterns were analyzed by high-throughput liquid chromatography mass spectrometry (LC-MS) metabolomics strategy coupled with chemometric evaluation. Sixteen metabolites (nine upregulated and seven downregulated) were differentially expressed and may thus serve as potential urinary biomarkers for human GC. These metabolites were mainly involved in multiple metabolic pathways, including citrate cycle (malic acid, succinic acid, 2-oxoglutarate, citric acid), cyanoamino acid metabolism (glycine, alanine), primary bile acid biosynthesis (glycine, taurine, glycocholic acid), arginine and proline metabolism (urea, l-proline), and fatty acid metabolism (hexadecanoic acid), among others. Network analysis validated close association between these identified metabolites and altered metabolic pathways in a variety of biological processes. These results suggest that urine metabolic profiles have great potential in detecting GC and may aid in understanding its underlying mechanisms. It provides insight into disease pathophysiology and can serve as the basis for developing disease biomarkers and therapeutic interventions for GC diseases.

Citric Acid Production in Yarrowia lipolytica SWJ-1b Yeast When Grown on Waste Cooking Oil

Abstract: In this study, citric acid was produced from waste cooking oil by Yarrowia lipolytica SWJ-1b. To get the maximal yield of citric acid, the compositions of the medium for citric acid production were optimized, and our results showed that extra nitrogen and magnesium rather than vitamin B1 and phosphate were needed for CA accumulation when using waste cooking oil. The results also indicated that the optimal initial concentration of the waste cooking oil in the medium for citric acid production was 80.0 g/l, and the ideal inoculation size was 1 × 107 cells/l of medium. We also reported that during 10-l fermentation, 31.7 g/l of citric acid, 6.5 g/l of isocitric acid, 5.9 g/l of biomass, and 42.1 g/100.0 g cell dry weight of lipid were attained from 80.0 g/l of waste cooking oil within 336 h. At the end of the fermentation, 94.6 % of the waste cooking oil was utilized by the cells of Y. lipolytica SWJ-1b, and the yield of citric acid was 0.4 g/g waste cooking oil, which suggested that waste cooking oil was a suitable carbon resource for citric acid production.

Obesity and Clinical Riskiness Relationship: Therapeutic Management by Dietary Antioxidant Supplementation--a Review.

Abstract: Obesity is a global health problem affecting all age groups, leading to many complications such as type 2 diabetes, systemic hypertension, cardiovascular disease, dyslipidemia, atherosclerosis, and stroke. Physiologically, obesity arises from metabolic changes in the tissues and organs of the human body; these changes result in an imbalance between energy intake and energy expenditure, which in turn results in increased fat accumulation in adipose tissue. Such fat accumulation predisposes individuals to development of several health problems. Two different obesity treatment drugs are currently on the market; Orlistat, which reduces intestinal fat absorption via inhibiting pancreatic lipase, and Sibutramine, an anorectic or appetite suppressant. Both drugs have hazardous side effects, including increased blood pressure, dry mouth, constipation, headache, and insomnia. For this reason, a wide variety of natural materials have been explored for their obesity treatment potential. Therefore, the present review focuses on the safety and efficacy of some herbal medicines in the management of obesity through covering their beneficial effects and mechanism of action.

Characterization of Plant Peroxidases and Their Potential for Degradation of Dyes: a Review

Abstract: Peroxidases are ubiquitously found in all vascular plants and are promising biocatalysts for oxidization of wide range of aromatic substrates including various industrial dyes. Peroxidases can catalyze degradation of chemical structure of aromatic dyes either by precipitation or by opening the aromatic ring structure. Both soluble and immobilized peroxidases have been successfully used in batches as well as in continuous processes for the treatment of aromatic dyes present in industrial effluents. Plant peroxidases are stable catalysts that retain their activities over a broad range of pH and temperatures. The performance of an enzyme for degradation process depends upon the structure of dyes and the operational parameters like concentration of enzyme, H2O2 and dye, incubation time, pH, and temperature. Recalcitrant dyes can also be mineralized by plant peroxidases in the presence of redox mediators. Thus, plant peroxidases are easily available, inexpensive, and ecofriendly biocatalysts for the treatment of wastewaters containing a wide spectrum of textile and non-textile synthetic dyes. This article reviews the recent developments in isolation and characterization of plant peroxidases and their applications for bioremediation of synthetic dyes.

An Improved Insecticidal Activity of Silver Nanoparticle Synthesized by Using Sargassum muticum

Abstract: A highly active silver nanoparticle (SmAgNps) was synthesized in the present study by using Sargassum muticum extract. The instrumentations such as scanning electron microscope (SEM), energy dispersive X-ray (EDAX), and X-ray diffraction (XRD) were used to reveal the nanoparticle morphology and size. The insecticidal activities of SmAgNps against Ergolis merione reveals prominent changes in the protein profile of hemolymph, morphology of hemocytes, and deteriorated midgut inclusions such as lumen, basement membrane, fat body, and gastric caeca. From this study, it was observed that phytochemicals of S. muticum was a prominent precursor for the synthesis of highly active nanoparticles.

Production of lactic acid from the mixture of softwood pre-hydrolysate and paper mill sludge by simultaneous saccharification and fermentation.

Abstract: Paper mill sludge is a solid waste material composed of pulp residues and ash generated from pulping and paper making process. The carbohydrate portion of the sludges from Kraft/Recycle paper mill has chemical and physical characteristics similar to those of commercial wood pulp. Because of its high carbohydrate content and well-dispersed structure, the sludge can be biologically converted to value-added products without pretreatment. In bioconversion of solid feedstock such as paper mill sludge, a certain amount of water must be present to attain fluidity. In this study, hemicellulose pre-hydrolysate, in place of water, was added to the sludge to increase the concentration of the final product. Pre-hydrolysate was obtained by hot-water treatment of pine wood in which the total sugar concentration reached 4 wt.%. The mixture was processed by simultaneous saccharification and fermentation (SSF) using enzymes (cellulase and pectinase) and Lactobacillus rhamnosus (ATCC-10863). Pectinase was added to hydrolyze mannose oligomers in the pre-hydrolysate to monomers. During the SSF of the mixture, calcium carbonate in the paper sludge acted as a buffer, yielding calcium lactate as the final product. External pH control was unnecessary due to the buffer action of calcium carbonate that maintained the pH near optimum for the SSF. The lactic acid yield in the range of 80–90 % of the theoretical maximum was obtained. Use of the mixed feed of pre-hydrolysate and pulp mill sludges in the SSF raised the product concentration to 60 g of lactate/L.