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Nutrient deprivation in a batch process induces microbes to produce secondary metabolites while drastically constraining cellular growth. A microfluidic continuous perfusion system was designed and tested to culture microalgae, Chlamydomonas reinhardtii , under constant nutrient concentration slightly lower than normal condition. When cultured in 7.5%/7.5% of NH 4 + /PO 4 2 − , C. reinhardtii showed a 2.4-fold increase in TAG production with a 3.5-fold increase in biomass compared to level obtained under an only NH 4 + depleted condition. The microfluidic continuous perfusion bioreactor with steady continuous nutrient flow can be used to optimize conditions for enhancing secondary metabolite production and increasing microbial biomass. [ABSTRACT FROM AUTHOR]

Encoded hydrogel particles have attracted attention in diagnostics as these particles can be used for high-performance multiplexed assays. Here, we present encoded tetragonal hydrogel microparticles for multiplexed detection of miRNAs that are strongly related to Alzheimer's disease (AD). The particles are comprised of vertically distinct code and probe regions, and incorporated with quantum dots (QDs) in the code regions. By virtue of the particle geometry, the particles can be synthesized at a high production rate in vertically stacked micro-flows using hydrodynamic focusing lithography. To detect multiple AD-miRNAs, various code labels to identify the loaded probes are designed by changing wavelengths of QDs, increasing the number of code layers and adjusting the thickness of code layers. The probe regions are incorporated with complementary sequences of target miRNAs, and optimized for accurate and timely detection of AD-miRNAs. For proof of concept, we demonstrate the multiplexed capability of the particles by performing a 3-plexed assay of AD-miRNAs. [ABSTRACT FROM AUTHOR]

Circulating tumor DNA (ctDNA) bearing tumor-specific mutation and methylation are promising biomarkers for noninvasive cancer assessment. However, existing methods for ctDNA detection are restricted to genetic mutations. Recently, nanoplasmonics has emerged as a platform for one-step dual detection with high sensitivity and specificity. Here we present a strategy for ultrasensitive detection of tumor-specific mutations (E542K and E545K) and methylation of ctDNA of PIK3CA gene based on localized surface plasmon resonance (LSPR) and the coupling plasmon mode of gold nanoparticles (AuNPs). Peptide nucleic acids (PNA) is used as a probe to capture and enrich the 69-bp PIK3CA ctDNA. The exposure of PNA-probed AuNPs to 200 fM ctDNA generates LSPR-peak shift of 4.3 nm, corresponding to the primary response. Immunogold colloids are exploited as methylation detectors and plasmon coupling based enhancement for secondary response. LSPR-peak shifted from 4.3 nm to 11.4 nm upon the immunogold colloids binding to two methylcytosines (mCpG), which is an approximately 107% increase, compared to that of the primary response. This enhancement leads to four times (~50 fM) improvement of sensitivity and because of two mCpG sites, ctDNA was detected. These results demonstrate that the sensor can simultaneously detect the hot-spot mutation and epigenetic changes on the ctDNA. Promisingly, other specific-tumor mutants and epigenetic changes can be detected at low concentration with this platform. [ABSTRACT FROM AUTHOR]

[Display omitted] • Astaxanthin production from H. pluvialis through CO 2 conversion has high potential. • With omics technologies, promising gene candidates for engineering can be suggested. • Heterotrophic-photoautotrophic culture strategy can boost astaxanthin productivity. • Sunlight combined with LEDs promotes field culture for astaxanthin production. • Process design considering the carbon cycle can secure the economic feasibility. Owing to its strong antioxidant properties, astaxanthin has a high market price in the nutraceutical and pharmaceutical fields, and its demand is increasing. Furthermore, with an increase in the demand for green technology, astaxanthin production through direct CO 2 conversion using the autotrophic green microalga Haematococcus pluvialis as a bio-platform has received much attention. Large-scale outdoor cultivation of H. pluvialis using waste CO 2 sources and sunlight can secure sustainability and improve economic efficiency. However, low strain performance, reduced light utilization because of increased cell density, and inefficient transfer of gaseous CO 2 into liquid culture broth hinder its large-scale commercialization of astaxanthin. Herein, we presented a multifaceted strategy, including the development of high-efficiency strains, a culture system for astaxanthin accumulation, and astaxanthin extraction from biomass, for economically producing astaxanthin from H. pluvialis through direct CO 2 conversion. Future perspectives were presented by comparing and analyzing various previous studies conducted using the latest technology. [ABSTRACT FROM AUTHOR]

Even though DNA-based nanosensors have been demonstrated for quantitative detection of analytes and diseases, hybridization events have never been numerically investigated for further understanding of DNA mediated interactions. Here, we developed a nanoscale platform with well-designed capture and detection gold nanoprobes to precisely evaluate the hybridization events. The capture gold nanoprobes were mono-laid on glass and the detection probes were fabricated via a novel competitive conjugation method. The two kinds of probes combined in a suitable orientation following the hybridization with the target. We found that hybridization efficiency was markedly dependent on electrostatic interactions between DNA strands, which can be tailored by adjusting the salt concentration of the incubation solution. Due to the much lower stability of the double helix formed by mismatches, the hybridization efficiencies of single mismatched (MMT) and perfectly matched DNA (PMT) were different. Therefore, we obtained an optimized salt concentration that allowed for discrimination of MMT from PMT without stringent control of temperature or pH. The results indicated this to be an ultrasensitive and precise nanosensor for the diagnosis of genetic diseases. [ABSTRACT FROM AUTHOR]

Abstract: Colloidal gold nanoparticles (AuNPs) and precipitation of an insoluble product formed by HRP-biocatalyzed oxidation of 3,3′-diaminobenzidine (DAB) in the presence of H2O2 were used to enhance the signal obtained from the surface plasmon resonance (SPR) biosensor. The AuNPs were synthesized and functionalized with HS-OEG3-COOH by self assembling technique. Thereafter, the HS-OEG3-COOH functionalized nanoparticles were covalently conjugated with horseradish peroxidase (HRP) and anti IgG antibody to form an enzyme–immunogold complex. Characterizations were performed by several methods: UV–vis absorption, DLS, HR-TEM and FT-IR. The Au–anti IgG–HRP complex has been applied in enhancement of SPR immunoassay using a sensor chip constructed by 1:9 molar ratio of HS-OEG6-COOH and HS-OEG3-OH for detection of anti-GAD antibody. As a result, AuNPs showed their enhancement as being consistent with other previous studies while the enzyme precipitation using DAB substrate was applied for the first time and greatly amplified the SPR detection. The limit of detection was found as low as 0.03ng/ml of anti-GAD antibody (or 200fM) which is much higher than that of previous reports. This study indicates another way to enhance SPR measurement, and it is generally applicable to other SPR-based immunoassays. [Copyright &y& Elsevier]

A biosensor chip utilizing surface plasmon resonance (SPR) was fabricated for detecting anti-glutamic acid decarboxylase (GAD) antibody, which is an indicator of the presence of type I diabetes mellitus. The sensor surfaces were constructed from various thiol mixtures of different molar ratios of 3-mercaptopropionic acid (3-MPA) to 11-mercaptoundecanoic acid (11-MUA). To determine the surface characteristics of the different alkanethiol monolayers, several quantitative and kinetic measurements were carried out. The extent of immobilization of streptavidin (SA) and biotin-GAD (the anti-GAD receptor) and the immune response of anti-GAD antibody against GAD were measured using the SPR biosensor. The terminal functional group of a thiol has different effects on the adsorption and covalent binding of protein depending on the steric hindrance. The protein chip described herein permits simple, rapid detection of anti-GAD antibody. [Copyright &y& Elsevier]

Cyanobacteria have the unique characteristic of using CO2 in the air as a carbon source and solar energy as an energy source. Reducing equivalents from the fermentation of carbohydrates are used as the primary electron donors in cyanobacteria for the hydrogen producing enzymes. The cells take up CO2 first to produce cellular substances, which are subsequently used for H2 production. Since the optimal operating conditions for the CO2 uptake and H2 production are different, a two-stage system can be effectively employed to separate these two phases. In this study, for the efficient production of H2 in the second stage, the conditions for the effective CO2 uptake and cell growth in the first stage were characterized, and high cell density culture was carried out using repeated injections of CO2. The specific growth rate and growth yield based on CO2 decreased with an increase in light intensity or CO2 concentration. However, the effect of CO2 concentration on the growth yield was much smaller than that of a light intensity. A CO2 uptake rate per unit cell decreased linearly with the initial CO2 concentration in the gas phase. With repeated injections of CO2, the CO2 was continuously consumed and the cell concentration reached 3.7 g dry cell/l in 20 days, which is 6.7 times higher than that in a batch culture without further supply of CO2. The CO2 injection in the cell growth phase increased not only the cell concentration but also the hydrogen production per gram cell. [Copyright &y& Elsevier]

• Split mixotrophy cultivation strategy (SMCS) improves growth conditions and lipid yields. • SMCS exhibited better energy recovery than the common mixotrophy. • SMCS solves the mixotrophic associated challenges like Chl reduction by glucose. • SMCS is promising for integrating dissimilar bioprocesses and cost-effectiveness. • SMCS exhibit rather more robust system than common mixotrophic cultivation. • Graphical abstact. Mixotrophy (M) assumes sum of autotrophic (A) and heterotrophic (H) growths. In this study, a novel split-mixotrophic cultivation strategy (SMCS) developed as better mixotrophy via offering mutual-benefits through gas-exchange at both headspaces while splitting both trophic modes. To quantify synergistic-growth effects in combined-autotrophy and combined-heterotrophy (CA&CH) of SMCS, gross O 2 -evolution, DIC and DO concentrations were compared with A, H and M. Average 12–14% and 26–32% increase in DIC and DO concentrations were determined respectively in CA and CH than A, H and M. Biomass yield in CA + CH was increased approx.1.5-folds higher than yields of A + H and M regimes. These results show SMCS as better cultivation strategy than the M by increased biomass and lipid yields. Challenges associated with organic carbon can be solved by SMCS viz. chlorophyll loss, organic carbon uptake inhibition. SMCS could be a breakthrough to integrate bacterial process with algae for better bioprocess economy and energy recovery. [ABSTRACT FROM AUTHOR]

[Display omitted] • Constitutive promoter P cpc560 has a high expression level even without any inducer. • The developed strain expressing phaCAB with P cpc560 produced 226 mg L−1 of PHB. • Supplying acetate is more effective than applying stresses in producing PHB. • Addition of 1 g L−1 of acetate resulted in 607.2 mg L−1 of PHB, a 2.7-fold increase. • The cost of additive for PHB production could be reduced by more than 300 times. Bioplastic production using cyanobacteria can be an effective strategy to cope with environmental problems caused by using petroleum-based plastics. Synechococcus elongatus UTEX 2973 with heterogeneous phaCAB can produce bioplastic polyhydroxybutyrate (PHB) with a high CO 2 uptake rate. For cost-effective production of PHB in S. elongatus UTEX 2973, phaCAB was expressed by the constitutive P cpc560 , resulting in the production of 226 mg/L of PHB by only photoautotrophic cultivation without the addition of inducer. Several culture conditions were applied to increase PHB productivity, and when acetate was supplied at a concentration of 1 g/L as an organic carbon source, productivity significantly increased resulting in 607.2 mg/L of PHB and additive cost reduction of more than 300 times was achieved compared to IPTG. Consequently, these results suggest the possibility of cyanobacteria as an agent that can economically produce PHB and as a solution to the problem of petroleum-based plastics. [ABSTRACT FROM AUTHOR]

Summary: Designing synthetic pathways for efficient CO2 fixation and conversion is essential for sustainable chemical production. Here we have designed a synthetic acetate‐acetyl‐CoA/malonyl‐CoA (AAM) bypass to overcome an enzymatic activity of pyruvate dehydrogenase complex. This synthetic pathway utilizes acetate assimilation and carbon rearrangements using a methyl malonyl‐CoA carboxyltransferase. We demonstrated direct conversion of CO2 into acetyl‐CoA‐derived acetone as an example in photosynthetic Synechococcus elongatus PCC 7942 by increasing the acetyl‐CoA pools. The engineered cyanobacterial strain with the AAM‐bypass produced 0.41 g/L of acetone at 0.71 m/day of molar productivity. This work clearly shows that the synthetic pyruvate dehydrogenase bypass (AAM‐bypass) is a key factor for the high‐level production of an acetyl‐CoA‐derived chemical in photosynthetic organisms. [ABSTRACT FROM AUTHOR]

Highlights • Thermostable cellulases from thermophiles can be expressed in mesophillic hosts. • Bacterial cellulase appears more promising when looked for thermostability. • Thermostable cellulases promise environmental and economical sustainability. • Thermostable cellulases allows hydrolysis to operate at elevated temperature. Abstract It is envisaged that the utilization of lignocellulosic biomass for ethanol production for transport sector, would make cellulases the most demanded industrial enzyme. The greatest potential of cellulolytic enzymes lies in ethanol production from biomass by enzymatic hydrolysis of cellulose but low thermostability and low titer of cellulase production resulting into high cost of the enzyme which is the major set-back. A number of research groups are working on cellulase to improve its thermostability so as to be able to perform hydrolysis at elevated temperatures which would eventually increase the efficiency of cellulose hydrolysis. The technologies developed from lignocellulosic biomass via cellulose hydrolysis promise environmental and economical sustainability in the long run along with non-dependence on nonrenewable energy source. This review deals with the important sources of thermostable cellulases, mechanism, its regulation, strategies to enhance the thermostability further with respect to its importance for biofuel applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Acidic cultivation of H. pluvialis is effective in P. sedebokerensis suppression. • Initial pH 4 was chosen to achieve contamination control and proper cell growth. • Contamination may be inhibited due to denaturation of a host-recognition lectin. • Stress relief strategies enhanced the astaxanthin titer by 104.8%. • Astaxanthin titer was thus upgraded 141-fold compared to contaminated H. pluvialis. Abstract An acidic cultivation strategy was developed to prevent contamination of a lethal fungus Paraphysoderma sedebokerensis in Haematococcus pluvialis culture for astaxanthin production. Instead of generally used neutral pH, an acidic condition (pH 4) was applied to the cultivation, resulting in a significant inhibition of the fungal contamination. This could be ascribed to the acidity-associated denaturation of a surface protein of P. sedebokerensis , which plays an important role in recognition of H. pluvialis. Stress relief strategies including stepwise light irradiation and naturally occurring nitrogen deficiency were employed in the induction stage to minimize the reduction of astaxanthin production caused by acidic pH. Accordingly, an astaxanthin titer of 84.8 mg L−1 was obtained, which is 141-fold of that from the completely contaminated culture and double of that without the stress relief methods. This strategy provides a persistent contamination control method that can be used for practical astaxanthin production by H. pluvialis. [ABSTRACT FROM AUTHOR]

Vibrational wave treatment has been used to increase proliferation of microalgae. When directly applied at large scale, however, turbulence can offset positive effects of vibration on microalgae proliferation. Moreover, severe hydrodynamic shear fields in the bioreactor decrease cell viability that detrimentally influence maximum yieldable biomass. In this study, vibration pretreatment (between 10–30 Hz and 0.15–0.45 G) was used to prime the cells for enhanced biomass. When exposed to 10 Hz at 0.15 G for 72 h and inoculated in baffled flasks of large shear fields (0.292 Pa for the average wall shear force (aveWSF) and 184 s −1 for the average shear strain rate (aveSSR)), microalgae showed 27% increase in biomass as well as 39% increase in corresponding amount of heterologous protein (i.e. GFP-3HA). Our results show that stress primed microalgae with vibrations can lead to improved proliferation that results in increased biomass production at industrial scale bioprocesses. [ABSTRACT FROM AUTHOR]

[Display omitted] • Waste soy sauce was used for mixotrophic cultivation of C. sorokiniana UTEX 2714. • Biomass and FAME production improved by 1.93 and 1.76 times, respectively. • The N and P source were effectively removed with an efficiency of over 90%. • Mixotrophic cultivation using actual industrial flue gas was further demonstrated. • Both biomass production and environmental remediation effect were achieved. Wastewater treatment plants are indispensable facilities, which emit a massive amount of greenhouse gases. To boost CO 2 mitigation and wastewater treatment performance, mixotrophic microalgae cultivation using wastewater has recently been proposed. In this study, food industry wastewater (waste soy sauce) was applied to Chlorella sorokiniana UTEX 2714 cultivation. By using a medium with 20% (v/v) of 10-fold diluted soy sauce, the biomass and fatty acid methyl ester (FAME) productivity enhanced by 1.93 and 1.76 times, respectively. Biomass productivity increased up to 5.2 times when using medium with high soy sauce content under high-intensity light that inhibits cell growth in photoautotrophic environments. Furthermore, industrial flue gas treatment with wastewater was demonstrated by outdoor semi-continuous cultivation with 42% improved biomass production. Consequently, these results suggest that mixotrophic microalgal cultivation has great potential to address both climate change and water pollution while producing valuable products and can contribute to building a sustainable society. [ABSTRACT FROM AUTHOR]

[Display omitted] • γ-Ray was used to select H. pluvialis mutants with strong environmental tolerance. • A selected mutant, M5, produced 101.57 mg L−1 of astaxanthin under salt conditions. • M5 showed 6 folds higher ω-3 production than wild type cells under salt conditions. • M5 showed 85% improved biomass than wild type cells under high light conditions. • M5 showed 84% higher astaxanthin content than wild type under high light conditions. This study was conducted to increase the productivity of biomass that contains high astaxanthin content by developing a mutant Haematococcus pluvialis strain with strong environmental tolerance. H. pluvialis has a low cell-growth rate and is vulnerable to stressors such as salinity or light intensity, which may hinder large-scale commercial cultivation. A mutant M5 strain selected through 5000-Gy gamma irradiation showed improved biomass and astaxanthin production under high-salinity and high-light intensity conditions. With enhanced SOD activity and overexpressed astaxanthin biosynthesis genes (lyc, crtR-b, bkt2), M5 demonstrated an increase in biomass and astaxanthin productivity by 86.70 % and 66.15 %, respectively compared to those of untreated cells. Also, the omega-3 content of M5 increased by 149.44 % under 40 mM CaCl 2 compared to the untreated cells. Finally, even when subjected to high-intensity light irradiation for the whole life cycle, the biomass and astaxanthin concentration increased by 84.99 % and 241 %, respectively, compared to the wild-type cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • The biomass productivity of H. pluvialis in the green stage was improved by using 1 g/L of glucose and sodium acetate. • Culturing H. pluvialis using glucose greatly increased biomass productivity owing to upregulation of glycolysis pathway. • Photosynthesis efficiency of H. pluvialis did not decrease significantly in mixotrophy with sodium acetate. The culture method using sodium acetate and glucose, widely used as organic carbon sources in the mixotrophy of Haematococcus pluvialis , was compared with its autotrophy. In the 12-day culture, mixotrophy using sodium acetate and glucose increased by 40.4% and 77.1%, respectively, compared to autotrophy, but the mechanisms for the increasing biomass were different. The analysis of the mechanism was divided into autotrophic and heterotrophic metabolism. The mixotrophy with glucose increased the biomass by directly supplying the substrate and ATP to the TCA cycle while inhibiting photosynthesis. Gene expressions related to glycolysis and carbon fixation pathway were confirmed in autotrophy and mixotrophy with glucose and acetate. The metabolism predicted in the mixotrophy with acetate and glucose was proposed via autotrophic and heterotrophic metabolism analysis. The mechanism of Haematococcus pluvialis under mixotrophic conditions with high CO 2 concentration was confirmed through this study. [ABSTRACT FROM AUTHOR]

Development of a new substrate for surface-enhanced Raman scattering (SERS) is one area of interest for the improvement of SERS performance. Herein, we introduce a new method for developing new mesoporous SERS substrates using M13 phages that display cysteine-rich peptides on the pVIII major units, which is an alternative for thiol donor using chemical modifications. Together with the SERS substrate development, and the use of the SERS technique for sepsis diagnostics is a new approach in clinical settings. The substrates were characterized and magnetized with magnetic immuno colloids made of gold-coated magnetic nanoparticles and specific antibodies. Conventionally, the SERS-tags are prepared by using gold nanoparticles and are modified with Raman dyes to immobilize specific antibodies to capture the biomarkers in the serum samples. However, in this method the SERS-tags are bound to the mesoporous substrate via antibody/antigen interactions to form clusters or layer-by-layer assemblies of SERS-tags for Raman signal enhancement. The SERS spectra showed distinct peaks for tags corresponding to three typical sepsis-specific biomarkers for diagnostics with the limit of detection values of 27 pM, 103 pM, and 78 pM for C-reactive protein (CRP), procalcitonin (PCT), and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), respectively. With such an approach, SERS can be used for clinical purposes and can be improved by phage display modification rather than chemical alternatives. [ABSTRACT FROM AUTHOR]

Extracellular vesicles (EVs) hold great promise as potential therapeutic carriers. EVs are biologically active, intrinsically transporting cargo between cells. Moreover, they can be loaded with specific cargo for distribution and/or engineered to achieve enhanced uptake. Although studies have already demonstrated therapeutic delivery using EVs, various challenges must be overcome before EV technology is ready for the clinic. Since the properties of EVs are dependent upon their cell of origin and the conditions of their formation, establishing clear characterization practices is essential to ensuring reproducibility and safety. Identifying methods for mass production of EVs is crucial for achieving high EV yields necessary for clinical trials. This review introduces current theory behind EV formation and function, describes the latest methods for characterization and mass production, and discusses future opportunities for extracellular vesicles in therapeutic delivery. [ABSTRACT FROM AUTHOR]

Capture and conversion of CO2 to valuable chemicals is intended to answer global challenges on environmental issues, climate change and energy security. Engineered cyanobacteria have been enabled to produce industry-relevant chemicals from CO2. However, the final products from cyanobacteria have often been mixed with fermented metabolites during dark fermentation. In this study, our engineering of Synechococcus elongatus PCC 7942 enabled continuous conversion of CO2 to volatile acetone as sole product. This process occurred during lighted, aerobic culture via both ATP-driven malonyl-CoA synthesis pathway and heterologous phosphoketolase (PHK)-phosphotransacetylase (Pta) pathway. Because of strong correlations between the metabolic pathways of acetate and acetone, supplying the acetyl- CoA directly from CO2 in the engineered strain, led to sole production of acetone (22.48 mg/ L ± 1.00) without changing nutritional constraints, and without an anaerobic shift. Our engineered S. elongatus strains, designed for acetone production, could be modified to create biosolar cell factories for sustainable photosynthetic production of acetyl-CoA-derived biochemicals. [ABSTRACT FROM AUTHOR]

• Real-time microalgal cell monitoring system was fabricated using 3D printer. • Correlation between microalgal cell growth and CO 2 fixation revealed. • Unreported photoautotrophic growth rate (4.497 g L−1 d−1) was observed. • Up to 70% of CO 2 introduced into the PBR could be mitigated by microalgae. The microalgae-based bioconversion process is a promising carbon utilization technology because it can upgrade CO 2 into valuable substances, but a multiplex monitoring system required for process control to maximize biomass productivity has not been well established. Herein, a 3D printed real-time optical density monitoring device (RTOMD) combined platform was presented. This platform enables precise kinetics analysis by maintaining high accuracy (over 95 %) under raucous outdoor conditions. Through RTOMD-based high-frequency measurements, it was observed that maximum biomass productivity of 4.497 g L−1 d−1 was reached, which greatly exceeds the requirements for a feasible microalgae process. We discovered that the CO 2 fixation efficiency could be achieved to 70.75 %, indicating the potential of a bioconversion process to realize a carbon–neutral society. Consequently, the RTOMD system can contribute to promoting microalgae cultivation as an attractive carbon mitigation technology based on an improved understanding of the photosynthetic CO 2 fixation kinetics. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microdroplet PBR effectively delivered light conditions mimicking natural sunlight. • Centrifugation of gel microdroplet enabled high-throughput screening of microalgae. • Selected mutant showed a 1.85-fold higher growth than wild-type in fluctuating light. • SNF2 mutant reduced ROS overproduction related to cell damage in light fluctuation. • The mutant promoted conversion of flue gas CO 2 to biofuel by 45.07% in field culture. Sunlight-driven microalgal conversion of CO 2 is a promising carbon neutral strategy for the sustainable production of various value-added products. However, its real-world application is challenging due to the irregularity of sunlight which reduces photosynthetic efficiency. Here, we report that microdroplet-based screening of photosynthesis-augmented microalgae mutant under fluctuating light accelerates mass production of CO 2 -derived algal biofuel in natural sunlight. Random insertional Chlamydomonas reinhardtii mutants were cultivated in single-layered microdroplet photobioreactors to be effectively applied to light conditions mimicking natural sunlight without self-shading. High-density microdroplets containing fast-growing mutants were efficiently selected at the single-droplet level by a centrifugation-assisted droplet sorting platform for high-throughput screening. Consequently, we isolated a mutant exhibiting cell growth 1.85-fold that of the wild-type even under continuous and rapid alteration in light intensity, which can serve as a cell stressor. After whole-genome resequencing, we found disruption in the SNF2 gene encoding ATP-dependent chromatin remodeling complexes, which reveal its importance for the regulation of chlorophyll biosynthesis and accumulation of reactive oxygen species under fluctuating light. After a 1.6 ton-scale field culture utilizing natural sunlight and industrial CO 2 , the mutant showed increased biomass productivity, CO 2 fixation rate, and calorific value, a crucial parameter of fuel performance, by 34.38%, 45.07%, and 16.82%, respectively. Our results indicate that improving photosynthesis of microalgae in fluctuating light environments elucidates the mechanisms responsible for enhancing the sunlight utilization, allowing industrial-scale biological CO 2 conversion. [ABSTRACT FROM AUTHOR]

The negative effect of heat stress on the autotrophic astaxanthin production by Haematococcus pluvialis has been observed during outdoor culture in summer. Under the summer conditions, the proliferation of vegetative cells was highly halted in the green stage and the inducibility in the biosynthesis of astaxanthin was partly hindered in the red stage. Herein, under outdoor summer conditions in which variations of the diurnal temperature occur, heat-stress-driven inefficient vegetative growth of H. pluvialis was highly improved by inoculating the red cyst cells; thereby, maintaining relatively moderate intracellular carotenoid levels in the green stage. Subsequently, a remarkably enhanced astaxanthin titer was successfully obtained by supplementing 50 μM iron(II) to induce the heat stress-driven Haber–Weiss reaction in the red stage. As a result, the productivity of astaxanthin in the cells cultured under summer temperature conditions (23.4–33.5 °C) using the two methods of red cell (cyst) inoculation and the iron(Fe 2+ ) supplementation was increased by 147% up to 5.53 mg/L day compared with that of the cells cultured under spring temperature conditions (17.5–27.3 °C). Our technical solutions will definitely improve the annual natural astaxanthin productivity in H. pluvialis in locations confronted by hot summer weather, particularly in large-scale closed photobioreactor systems. [ABSTRACT FROM AUTHOR]

The development of highly sensitive, selective and multiplex sensors has become an important challenge for disease diagnosis. In this study, we describe a multiplex biosensor for the detection of cancer biomarkers based on unique plasmon response of single gold nanoparticles (AuNPs) and antibody–antigen binding activity. To demonstrate the ability of the plasmon biosensor to detect and quantify cancer biomarkers: a panel of biomarkers, including α-fetoprotein (AFP), carcinoembryonic antigen (CEA) and prostate specific antigen (PSA) was used as a model analyte for multiple detection. A novel and sensitive multiplex biosensor was developed by immobilizing plasmonic nanoparticles in a site-specific manner and functionalized with monoclonal antibodies that recognize the target protein on hydrophilic–hydrophobic patterned glass slide. The proposed multi-analyte biosensor exhibited outstanding selectivity and sensitivity. The limit of detection was determined to be 91 fM, 94 fM and 10 fM for AFP, CEA and PSA from patient-mimicked serum, respectively. Finally, using this sensing strategy, this platform presents an excellent approach for versatile molecular diagnostics in both research and clinical medical fields. [ABSTRACT FROM AUTHOR]

Haematococcus pluvialis is the richest source of natural astaxanthin (3S, 3′S), but the rigid cell wall of mature red cyst (aplanospore) complicates the efficient extraction of astaxanthin from the strain. Herein, the cyst germination method was developed by using nitrate and light for practical application for an efficient astaxanthin extraction from Haematococcus cells cultured in outdoor condition where flue gas, solar radiation and photobioreactor were used. Notably, autotrophic germination rate was easily regulated by light intensity. Under conditions of low germination rate, total astaxanthin concentration was highly maintained and astaxanthin extraction efficiency was rapidly enhanced during autotrophic germination. As a result, under homogenization (30 s), the extracted astaxanthin concentration in the cells treated with 1 mM KNO 3 –150 μE/m 2 /s was highly increased by 58% compared to the cells treated without germination. Our technical solution will definitely improve an astaxanthin extraction titer with the practical application in outdoor Haematococcus culture system. [ABSTRACT FROM AUTHOR]

Autophagy is a fundamental intracellular catabolic process that degrades cytoplasmic constituents to maintain cellular homeostasis. Since autophagy-targeting cancer therapies are gaining attention for their association with cancer progression and drug resistance, the need to develop rapid and precise autophagic flux measurement to evaluate the efficacy of chemotherapies is critical. Here, we present a localized surface plasmon resonance (LSPR) based two-step sensing platform, enabling microtubule-associated proteins 1 A/1B light chain 3 (LC3) turnover assay, measuring LC3-I conversion to LC3-II, which indicates autophagic flux. This work represents an improvement made to our previous total LC3 detecting sensor by measuring specific LC3 ratios within a wide dynamic concentration range from 102 to 106 fM with the treatment of phosphatidylethanolamine binding protein 1 (PEBP1). Furthermore, it enables autophagic flux measurement without any limitation in LC3 compositions of clinical samples, compared to the sensor of our previous study. The sensor successfully analyzed the drug efficacy with high sensitivity under clinical conditions where autophagy-targeted drugs were treated to human cancer cell lines. Our results suggest that this sensor, capable of quantifying individual LC3 forms in a single platform, can be utilized as a rapid, convenient, and cost-effective drug discovery tool in relevance with autophagy-targeted chemotherapies. • The first autophagic flux assay tool that individually quantifies LC3-I and LC3-II. • The LSPR biosensor can analyze samples mimicking those in clinical conditions. • Sensor detected changes in LC3 expression of cancer cells following drug treatment. • Specific equation correlating LSPR shifts and LC3 compositions was obtained. [ABSTRACT FROM AUTHOR]

Epigenetic changes, particularly in cancer suppressor genes, are novel biomarkers for cancer diagnostics and therapeutics. However, epigenetic studies should not only provide an estimation of the amount of 5-methylcytosine, but also examine the presence of epigenetic proteins to reveal the complete epigenetic alterations for downstream molecular process. The challenge of natural epigenetics is to unveil key factors of epigenetics in one assay, containing low concentrations. This would be valuable for the monitoring of early-stage cancer. On the basic of the nanoplasmonic biosensor, here we report a sensitive sensor to study epigenetics of DNA promoter. The results show detection limit for dual epigenetic biomarkers methyl-CpG group and methyl-CpG binding domain protein 2 (MBD2) are one 5-methylcytosine molecule and 125 fM MBD2. Moreover, DNA structure bending, steric competition under interaction of epigenetic proteins and transcription factors; and epigenetics-mediated suppression of transcription are observed during epigenetic alterations. This study provides a platform for full story of epigenetics, as compared with that of methylcytosine-based techniques only. [ABSTRACT FROM AUTHOR]

Pretreatment of lignocellulosic biomass by acid hydrolysis generates growth inhibitors such as furfural, 5-hydroxymethylfurfural, and acetic acid. Among the inhibitors, furfural strongly inhibits cell growth, our objective was to identify the furfural stimulon of an amino acid producer Corynebacterium glutamicum using transcriptomic analysis. As a result, 182 up-regulated (2-fold) genes and 81 down-regulated (0.5-fold) genes were identified for all furfural stress conditions (6.5 mM, 13 mM, and 20 mM). Based on the functional categories of CoryneRegNet database, the furfural stimulon was related to genetic responses of oxidative stress, SOS responses, and anaerobic respiratory metabolism. To overcome the furfural toxicity, furfural-responsive efflux-like permease encoded by the cg1661 gene was overexpressed, resulting that the optical density at 600 nm was 1.54-fold enhanced over the control at 12 h. This study provides alternative strategy of metabolic engineering for biological detoxification in addition to overexpression of NADH-dependent reductases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microwaves can assist in targeted bioconversion of algal biomass to fuels. • Hydrothermal carbonization energy efficient for solid microalgal fuel preparation. • Flash hydrolysis and hydrothermal liquefaction: efficient methods for liquid fuels. • Liquid fuel production from microalgae requires catalyst addition for higher yield. • Ultrasound assisted photofermentation can yield higher biohydrogen from microalgae. Traditional methods of fuel production and consumption result in the emission of huge quantities of CO 2 , leading to a rise in the Earth's surface temperature. This has driven the scientific community to look for alternate sources of fuels that could fulfil the current energy demands, while reducing CO 2 emissions. Microalgae have garnered substantial interest as an excellent biological resource for biorefineries, given their abilities to accumulate diverse CO 2 -derived bioproducts, such as various forms of fuels, chemical building blocks, and pharmaceuticals; this could be interpreted as an efficient method for storing solar energy by biological means. Microalgal biomass is free from ethical debates because it does not compete with food production for fertile arable lands and clean water for their cultivation, which makes the entire process highly sustainable. Microalgal biomass-derived fuels for each end-use can be obtained via several processes, including drying, chemical, and physical lipid-extraction methods, anaerobic digestion, and thermochemical treatments (e.g. , pyrolysis, torrefaction, hydrothermal carbonization, liquefaction, and gasification). This review aims to critically explore the process layouts, their operation conditions (including catalysts), and expected outputs related to fuel production. It also provides a comprehensive overview of the most notable and promising strategies for the producing energy resources from various species of microalgae. Pretreatment of microalgal biomass, followed by bioconversion strategies, such as hydrothermal carbonization and photo-fermentation, along with genomics-based approaches, can lead to higher yields of microalga-derived solid, liquid, and gaseous fuels. [ABSTRACT FROM AUTHOR]

Background: The photosynthetic microorganism Chlamydomonas reinhardtii has been approved as generally recognized as safe (GRAS) recently, this can excessively produce carotenoid pigments and fatty acids. Zeaxanthin epoxidase (ZEP), which converts zeaxanthin to violaxanthin, and ADP-glucose pyrophosphorylase (AGP). These are key regulating genes for the xanthophyll and starch pathways in C. reinhardtii respectively. In this study, to produce macular pigment-enriched microalgal oil, we attempted to edit the AGP gene as an additional knock-out target in the zep mutant as a parental strain. Results: Using a sequential CRISPR-Cas9 RNP-mediated knock-out method, we generated double knock-out mutants (dZAs), in which both the ZEP and AGP genes were deleted. In dZA1, lutein (2.93 ± 0.22 mg g−1 DCW: dried cell weight), zeaxanthin (3.12 ± 0.30 mg g−1 DCW), and lipids (450.09 ± 25.48 mg g−1 DCW) were highly accumulated in N-deprivation condition. Optimization of the culture medium and process made it possible to produce pigments and oil via one-step cultivation. This optimization process enabled dZAs to achieve 81% higher oil productivity along with similar macular pigment productivity, than the conventional two-step process. The hexane/isopropanol extraction method was developed for the use of macular pigment-enriched microalgal oil for food. As a result, 196 ± 20.1 mg g−1 DCW of edible microalgal oil containing 8.42 ± 0.92 mg g−1 lutein of oil and 7.69 ± 1.03 mg g−1 zeaxanthin of oil was produced. Conclusion: Our research showed that lipids and pigments are simultaneously induced in the dZA strain. Since dZAs are generated by introducing pre-assembled sgRNA and Cas9-protein into cells, antibiotic resistance genes or selective markers are not inserted into the genome of dZA, which is advantageous for applying dZA mutant to food. Therefore, the enriched macular pigment oil extracted from improved strains (dZAs) can be further applied to various food products and nutraceuticals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Commercial use of H. pluvialis to produce astaxanthin and ω-3 FA has been reviewed. • Possible contaminations in different cultivation systems are discussed. • Biological pollutant species and their contamination modes are presented. • Decontamination technologies according to biocontaminants are introduced. • Further cost-effective strategies on controlling the contaminants are necessary. With industrialization, anthropogenic mishandlings have resulted in the discharge of abundant amount of CO 2 into the atmosphere. This has triggered an unnatural warming that has dramatically increased the Earth's temperature in a short duration. This problem can be addressed by the biological conversion of CO 2 ; several studies have been conducted using H. pluvialis culture that produces high value-added materials, such as astaxanthin and omega-3 fatty acids. However, although H. pluvialis has a high market value, the market size is quite small. Because H. pluvialis cells are susceptible to contamination due to its slow growth rate, hence large-scale culture of H. pluvialis without reliable contamination control strategies poses significant risks. This review comprehensively discusses the contamination that occurs during the culturing of H. pluvialis in various culture systems under different culture conditions. The review also discusses the strategies in controlling the biotic contaminants, such as bacteria and fungi. [ABSTRACT FROM AUTHOR]

Autophagy is a cellular catabolic process that plays significant roles in various diseases such as neurodegenerative diseases, infectious diseases, and cancers. The importance of microtubule-associated protein 1 light chain 3 (LC3) quantification is highlighted because it is a precise tool for measuring autophagy and is also known to be associated with cancer progression, functioning as a clinically significant marker in cancer diagnosis and prognosis. To date, the quest continues to develop an autophagic LC3 detection method with enhanced sensitivity, and which provides a means of quantification to meet the clinical application needs. Here, we present a simple and intuitive autophagy flux measurement by a single gold nanoparticle-based LC3 sensing platform. This nanoplasmonic sensor does not require additional labeling, consisted of only gold nanorods and monoclonal antibodies, which enables rapid total LC3 quantification within a wide dynamic concentration range, with a detection limit of 64.1 fM. Moreover, the sensing ability of the proposed biosensor in cell lysates mimicking clinical samples and human cancer cell lysates was proved by providing a simple autophagic flux analysis method based on LSPR shifts. This sensor is the first label-free, highly sensitive total LC3 quantification nanoplasmonic biosensor that can be used for autophagy measurement, employed for precise cancer diagnosis in combination with other biomarkers. It can serve as an effective tool for determining therapeutic drug dosage in the future. • Nanoplasmonic biosensor for detection of LC3 autophagy markers was developed for the first time. • High sensitivity and low detection limit of LC3 autophagy markers were achieved without additional labeling. • The sensing ability of LC3 autophagy markers in clinically mimicking samples and human cancer cell lysates was proved. • An intuitive autophagy flux measurement method utilizing the nanoplasmonic biosensor was presented. [ABSTRACT FROM AUTHOR]

The differential diagnosis between mild cognitive impairment (MCI) and Alzheimer's disease (AD) has been highly demanded for its effectiveness in preventing and contributing to early diagnosis of AD. To this end, we developed a single plasmonic asymmetric nanobridge (PAN)-based biosensor to differentially diagnose MCI and AD by quantitative profiling of phosphorylated tau proteins (p-tau) in clinical plasma samples, which revealed a significant correlation with AD development and progression. The PAN was designed to have a conductive junction and asymmetric structure, which was unable to be synthesized by the traditional thermodynamical methods. For its unique morphological characteristics, PAN features high electromagnetic field enhancement, enabling the biosensor to achieve high sensitivity, with a limit of detection in the attomolar regime for quantitative analysis of p-tau. By introducing support vector machine (SVM)-based machine learning algorithm, the improved diagnostic system was achieved for prediction of healthy controls, MCI, and AD groups with an accuracy of 94.47 % by detecting various p-tau species levels in human plasma. Thus, our proposed PAN-based plasmonic biosensor has a powerful potential in clinical utility for predicting the onset of AD progression in the asymptomatic phase. [ABSTRACT FROM AUTHOR]

The outbreak of emerging infectious diseases gave rise to the demand for reliable point-of-care testing methods to diagnose and manage those diseases in early onset. However, the current on-site testing methods including lateral flow immunoassay (LFIA) suffer from the inaccurate diagnostic result due to the low sensitivity. Herein, we present the surface-enhanced Raman scattering-based lateral flow immunoassay (SERS-LFIA) by introducing phage-templated hierarchical plasmonic assembly (PHPA) nanoprobes to diagnose a contagious disease. The PHPA was fabricated using gold nanoparticles (AuNPs) assembled on bacteriophage MS2, where inter-particle gap sizes can be adjusted by pH-induced morphological alteration of MS2 coat proteins to provide the maximum SERS amplification efficiency via plasmon coupling. The plasmonic probes based on the PHPA produce strong and reproducible SERS signal that leads to sensitive and reliable diagnostic results in SERS-LFIA. The developed SERS-LFIA targeting severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) antibodies for a proof of concept had <100 pg/mL detection limits with high specificity in serum, proving it as an effective diagnostic device for the infectious diseases. Clinical validation using human serum samples further confirmed that the PHPA-based SERS-LFIA can distinguish the patients with COVID-19 from healthy controls with significant accuracy. These outcomes prove that the developed SERS-LFIA biosensor can be an alternative point-of-care testing (POCT) method against the emerging infectious diseases, in combination with the commercially available portable Raman devices. • A SERS-LFIA biosensor adopted pH-induced PHPA structure as advanced nanoprobe was developed. • PHPA used MS2 phage as a scaffold with tailorable size in response to pH, for strong SERS intensity. • The SERS-LFIA had the detection limit below 100 pg/mL for the antibodies against SARS-CoV-2. • Through the clinical validation, the SERS-LFIA demonstrated excellent diagnostic accuracy. [ABSTRACT FROM AUTHOR]

[Display omitted] • A strategic way to use CO 2 in microalgae cultivation and pyrolysis was proposed. • Microalgal species, Scenedesmus sp., was cultivated under a high CO 2 condition (5%). • The syngas yield from catalytic pyrolysis under CO 2 was higher than that of N 2. • Ni-based catalyst enhanced CO formation 2.92 times higher under CO 2 condition. • Catalytic pyrolysis under CO 2 can mitigate the PAH content in pyrolytic oil. Microalgal biomass is a promising candidate for next generation biorefinery resources because of its rapid growth rate and efficiency in carbon assimilation. Recent studies have reported successful microalgal cultivation using exhaust gases rich in CO 2 as the carbon source. This study focuses on optimising carbon utilisation by incorporating CO 2 into the pyrolysis process of microalgae, particularly Scenedesmus sp., cultivated under elevated CO 2 concentrations. Under the influence of CO 2 , homogeneous reactions occurred between the volatile pyrolysates and CO 2. These reactions result in enhanced CO levels and a reduction in polycyclic aromatic hydrocarbons (PAHs) in pyrolytic oil through the simultaneous reduction of CO 2 and oxidation of volatile pyrolysates. To accelerate the kinetics of these homogeneous reactions, catalytic pyrolysis was performed using Ni-based catalysts. The catalytic effects of The Ni catalyst significantly boosted CO production by promoting homogeneous reactions. The evolution of CO from catalytic pyrolysis under CO 2 conditions was 2.92 times higher than that from double-stage pyrolysis. Thus, these experimental findings underscore the technical advantages of strategically utilising CO 2 in both microalgal biomass cultivation and the thermochemical conversion of microalgal biomass. [ABSTRACT FROM AUTHOR]

Modification of structural components, especially the cell wall, through adequate pretreatment strategies is critical to the bioconversion efficiency of algal biomass to biorefinery products. Over the years, several physical, physicochemical, chemical and green pretreatment methods have been developed to achieve maximum productivity of desirable by-products to sustain a circular bioeconomy. The effectiveness of the pretreatment methods is however, species specific due to diversity in the innate nature of the microalgal cell wall. This review provides a comprehensive overview of the most notable and promising pretreatment strategies for several microalgae species. Methods including the application of stress, ultrasound, electromagnetic fields, pressure, heat as well as chemical solvents (ionic liquids, supercritical fluids, deep eutectic solvents etc.) have been detailed and analyzed. Enzyme and hydrolytic microorganism based green pretreatment methods have also been reviewed. Metabolic engineering of microorganisms for product specificity and lower inhibitors can be a future breakthrough in microalgal pretreatment. • Microwave assisted methods appear promising for physical pretreatment. • Pressurized liquid extraction efficient for pigments and antioxidants recovery. • Supercritical fluid extraction promising for oil recovery. • Choline chloride-based deep eutectic solvent superior to ionic liquid extraction. • Engineered microbes could provide product specificity, ensuring higher yields. [ABSTRACT FROM AUTHOR]

Abstract: The co-crystal approach has been investigated extensively over the past decade as one of the most promising methods to enhance the dissolution properties of insoluble drug substances. Co-crystal powders are typically produced by mechanical grinding (neat or wet) or a solution method (evaporation or cooling). In this study, high-purity carbamazepine-saccharin (CBZ–SAC) co-crystals were manufactured by a novel method, anti-solvent addition. Among various solvents, methanol was found to perform well with water as the anti-solvent for the co-crystallization of CBZ and SAC. When water was added to the methanol solution of CBZ and SAC at room temperature under agitation, nucleation of CBZ–SAC co-crystals occurred within 2–3min. Co-crystallization was complete after 30min, giving a solid yield as high as 84.5% on a CBZ basis. The effects of initial concentrations, focusing on the SAC/CBZ ratio, were examined to establish optimal conditions. The whole anti-solvent co-crystallization process was monitored at-line via ATR-FTIR analysis of regularly sampled solutions. The nucleation and crystal growth of CBZ–SAC co-crystals were detected by a significant increase in absorption in the range of 2400–2260cm−1, associated with the formation of hydrogen bonds between the carbonyl group in CBZ and the N–H of SAC. When CBZ hydrates were formed as impurities during anti-solvent co-crystallization, the hydrogen bonding between methanol and water was reduced greatly, primarily due to the incorporation of water molecules into the CBZ crystal lattice. In conclusion, an anti-solvent approach can be used to produce highly pure CBZ–SAC co-crystal powders with a high solid yield. [Copyright &y& Elsevier]

Abstract: We report the use of plasmonic responses of single gold nanoparticles (AuNPs) with various sizes for the analysis of biomolecular recognition. We also describe the relationship between particle size and plasmonic response induced by the binding of receptors and target analytes. To investigate the plasmonic response of AuNPs, Rayleigh light scattering spectra were collected from individual AuNPs using a dark-field microspectroscopy system. Using prostate-specific antigen (PSA) as a model, the linear dynamic range was obtained in the concentration range of 10−4 to 10ng/ml, with the smallest detectable concentration at 0.1pg/ml corresponding to localized surface plasmon resonance (LSPR) λ max shifts of approximately 2.95nm. This result indicates that individual AuNPs can be used for development of a very sensitive, robust, simple, and label-free biosensor to detect protein biomarkers. Furthermore, the method possesses great potential for monitoring other biological interactions. [Copyright &y& Elsevier]

Abstract: Biohydrogen fermentation by the hyperthermophile Thermotoga neapolitana was conducted in a continuously stirred anaerobic bioreactor (CSABR). The production level of H2 from fermentation in a batch culture with pH control was much higher than without pH control from pentose (xylose) and hexose (glucose and sucrose) substrates. The respective H2 yield in the batch culture with pH control from xylose and glucose was 2.22 ± 0.11 mol-H2 mol−1 xyloseconsumed and 3.2 ± 0.16 mol-H2 mol−1 glucoseconsumed, which was nearly 1.2-fold greater for xylose and 1.6-fold greater for glucose than without pH control. In the case of sucrose, the H2 yield from fermentation increased by 40.63%, compared with fermentation in batch cultures without pH control, from 3.52 ± 0.171 to 4.95 ± 0.25 mol-H2 mol−1 sucroseconsumed. The effects of stirring speed and different pH levels on growth and H2 production were studied in the CSABR for highly efficient H2 production. Growth and H2 production of this bacterial strain in a batch culture with pH control or without pH control using a 3 L bioreactor was limited within 24 h due to substrate exhaustion and a decrease in the culture’s pH. The pH-controlled fed-batch culture with a xylose substrate added in doses was studied for the prevention of substrate-associated growth inhibition by controlling the nutrient supply. The highest H2 production rates were approximately 4.6, 4.1, 3.9, and 4.3 mmol-H2 L−1 h−1 at 32, 52, 67, and 86 h, respectively. [Copyright &y& Elsevier]

Abstract: Herein, we demonstrate three strategies of signal amplification for ultrasensitive detection of human immunoglobulin E (hIgE) based on poly(di-acetylene) supramolecules. To fabricate the ultrasensitive PDA biosensor, ethylenediamine as an interlinker and aptamer as a receptor were introduced into the chip fabrication process. Using the prepared PDA liposome biosensor, the hIgE could be detected up to below 1.0ng/ml by a primary response. In order to accomplish more ultrasensitive detection of protein on a PDA biosensor, polyclonal hIgE antibody was employed as an external mechanical force for the inducement of a secondary response. As a result, a PDA liposome biosensor sensitivity as high as 0.01ng/ml for the target hIgE was obtained, with a sensitivity which is one hundred times of that of the method without signal amplification. These results indicate that the proposed strategies were capable of ultrasensitive quantitative and qualitative analyses of biomolecules without non-specific binding of non-target proteins. [Copyright &y& Elsevier]

Abstract: Efficient conversion of glycerol waste from biodiesel manufacturing processes into biohydrogen by the hyperthermophilic eubacterium Thermotoga neapolitana DSM 4359 was investigated. Biohydrogen production by T. neapolitana was examined using the batch cultivation mode in culture medium containing pure glycerol or glycerol waste as the sole substrate. Pre-treated glycerol waste showed higher hydrogen (H2) production than untreated waste. Nitrogen (N2) sparging and pH control were successfully implemented to maintain the culture pH and to reduce H2 partial pressure in the headspace for optimal growth rate and to enhance hydrogen production from the glycerol waste. It was found that hydrogen production increased from 1.24 ± 0.06 to 1.98 ± 0.1 mol-H2 mol−1 glycerolconsumed by optimising N2 sparging and pH control. We observed that in medium containing 0.05 M HEPES, with three cycles of N2 sparging, the H2 yield increased to 2.73 ± 0.14 mol-H2 mol−1 glycerolconsumed, which was 2.22-fold higher than the non-N2 sparged H2 yield (1.23 ± 0.06 mol-H2 mol−1 glycerolconsumed). [Copyright &y& Elsevier]

Abstract: In this study, hybrid stimulus was initially introduced to improve the sensitivity of PDA vesicle chip for detection of prostate-specific antigen-α1–antichymotrypsin (PSA–ACT) complex. The strategy of hybrid stimulus on PDA vesicle chip offers the amplification method of fluorescent signal which combines a primary response by the immune reaction of antigen–antibody and a secondary response by the mechanical pressure of pAb-conjugated magnetic beads. As the primary response result on PDA vesicle chip, the PSA–ACT complex in PBS buffer was detected at 10ng/mL. However, this detection sensitivity was insufficient for diagnosis of prostate cancer because the normal human PSA concentration is less than 4.0ng/mL. To solve this problem, polyclonal PSA antibody-conjugated magnetic beads were used as an amplifying agent after primary immunoresponse. As a result, the PSA–ACT complex concentrations (as low as 0.1ng/mL) could be detected in the PBS buffer sample. Therefore, this result can be applied to various fields, such as the detection of cells, proteins, and DNA for sensitive and specific biosensing based on PDA supramolecules. [ABSTRACT FROM AUTHOR]

Abstract: Quantitative detection of specific viral DNA has become a pressing issue for the earlier clinical diagnosis of viral infectious diseases. Therefore, in this paper, we report a simple, sensitive, and inexpensive quantitative approach for DNA detection based on the autocatalytic Au deposition of gold nanoprobes via the surface reduction of AuCl4 − to Au0 on their surface in the presence of ascorbic acid (AA) and cetyltrimethylammonium bromide (CTAB). On this basis, signal enhancements in the absorbance intensity and kinetic behavior of gold enlargement in the aqueous phase have been well investigated and explained for the selection of analytical parameters. To achieve high sensitivity, magnetic particles conjugated with capture probes (PMPs) were employed for the collection of gold nanoprobes. After denaturated by ion a pH 11 solution, the amplified signals of gold nanoprobes, which is proportional to the concentration of the target DNA, could easily be confirmed by a UV–vis scanning spectrophotometer. Limit of detection could be obtained as low as 1.0fM by this simple method. [ABSTRACT FROM AUTHOR]

Abstract: The production of ethanol from feedstock other than agriculture materials has been promoted in recent years. Some microalgae can accumulate a high starch content (about 44% of dry base) via photosynthesis. Algal biomass, Chlamydomonas reinhardtii UTEX 90, was converted into a suitable fermentable feedstock by two commercial hydrolytic enzymes. The results showed that almost all starch was released and converted into glucose without steps for the cell wall disruption. Various conditions in the liquefaction and saccharification processes, such as enzyme concentration, pH, temperature, and residence time, have been investigated to obtain an optimum combination using the orthogonal analysis. As a result, approximately 235mg of ethanol was produced from 1.0g of algal biomass by a separate hydrolysis and fermentation (SHF) method. The main advantages of this process include the low cost of chemicals, short residence time, and simple equipment system, all of which promote its large-scale application. [Copyright &y& Elsevier]

Abstract: Gold-coated magnetic nanoparticles were synthesized with size ranging from 15 to 40nm using sodium citrates as the reducing agent. Oxidized magnetites (Fe3O4) fabricated by co-precipitation of Fe2+ and Fe3+ in strong alkaline solution were used as magnetic cores. The structures of gold (Au) shell and magnetic core (Au–Fe) were studied by transmission electron microscopy (TEM) image and energy dispersive spectroscopy (EDS) spectrum. Results from high-resolution X-ray diffraction (HR XRD) show that the Au–Fe oxide nanoparticles have a face-centered cubic shape with the crystalline faces of {111}. The Au-coated magnetic nanoparticles exhibited a surface plasmon resonance peak at 528nm. The nanoparticles are well dispersed in distilled water. A 3000G permanent magnet was successfully used for the separation of the functionalized nanoparticles. Magnetic properties of the nanoparticles were determined by magnetic force microscope (MFM) in nanometric resolution and vibrating sample magnetometer (VSM). Magnetic separation of biological molecules using Au-coated magnetic oxide composite nanoparticles was examined after attachment of protein immunoglobulin G (IgG) through electrostatic interactions. Using this method, separation was achieved with a maximum yield of 35% at an IgG concentration of 400ng/ml. [Copyright &y& Elsevier]

Abstract: We report a seedless synthetic method of gold octahedral nanoparticles in an aqueous phase. Eight facets with {111} crystalline structures of octahedral nanoparticles could be formed in an aqueous medium when the gold salt was reduced by ascorbic acid at room temperature in the presence of cetyltrimethylammonium bromide as a shape-inducing agent, and hydrogen peroxide as a reaction promoter. The growth kinetics and surface crystalline structures were characterized by UV–vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy. [Copyright &y& Elsevier]

Abstract: To enhance the feasibility of surface plasmon resonance (SPR) immunosensor as a tool for diagnosing type I diabetes, we enhanced the sensitivity of immunoresponse for detecting the monoclonal anti-glutamic acid decarboxylase (GAD) antibody by modification of mixed self-assembled monolayers (SAMs). The effects of the different mixed SAMs were evaluated with respect to the degree of streptavidin immobilization, the degree of biotin–GAD immobilization, and the immunoresponse sensitivity. Consequently, the sensitivity of the immunoresponse for the detection of anti-GAD antibody was enhanced as a result of the reduction in steric hindrance brought about by using SAMs of heterogeneous lengths. The immunoresponse for detecting the monoclonal anti-GAD antibody was also enhanced with the reduction of the excess immobilization of biotin–GAD and the minimization of non-specific binding that resulted from the simple substitution of the spacer from a carboxylic-terminated SAM for the hydroxyl-terminated SAM. [Copyright &y& Elsevier]

Abstract: The recombinant ferritin heavy chain (FTN-H) formed self-assembled spherical nanoparticles with the size comparable to native one. We tried to express the GAD65 COOH-terminal fragments, i.e., 448–585 (GAD65448–585), 487–585 (GAD65487–585), and 512–585 (GAD65512–585) amino acid fragments, using FTN-H as N-terminus fusion expression partner in Escherichia coli. All of recombinant fusion proteins (FTN-H::GAD65448–585, FTN-H::GAD65487–585, and FTN-H::GAD65512–585) also formed spherical nanoparticles due probably to the self-assembly function of the fused ferritin heavy chain. The antigenic epitopes within GAD65448–585, GAD65487–585, and GAD65512–585 against insulin-dependent diabetes mellitus (IDDM) marker (autoantibodies against GAD65) were localized at the surface of the spherical protein nanoparticles so that anti-GAD65 Ab could recognize them. Protein nanoparticles like FTN-H seem to provide distinct advantages over other inorganic nanoparticles (e.g., Au, Ag, CdSe, etc.) in that through the bacterial synthesis, the active capture probes can be located at the nanoparticle surface with constant orientation/conformation via covalent cross-linking without complex chemistry. Also it is possible for the protein nanoparticles to have uniform particle size, which is rarely achieved in the chemical synthesis of inorganic nanoparticles. Thus, the recombinant ferritin particles can be used as a three-dimensional (spherical) and nanometer-scale probe structure that is a key component in ultra-sensitive protein chip for detecting protein–small molecule interactions and protein–protein interactions. [Copyright &y& Elsevier]