Deciphering role of technical bioprocess parameters for bioethanol production using microalgae

Microalgae biomass is considered an important feedstock for biofuels and other bioactive compounds due to its faster growth rate, high biomass production and high biomolecules accumulation over first and second-generation feedstock. This research aimed to maximize the specific growth rate of fresh water green microalgae Closteriopsis acicularis, a member of family Chlorellaceae under the effect of pH and phosphate concentration to attain enhanced biomass productivity. This study investigates the individual and cumulative effect of phosphate concentration and pH on specific growth characteristics of Closteriopsis acicularis in autotrophic mode of cultivation for bioethanol production. Central-Composite Design (CCD) strategy and Response Surface Methodology (RSM) was used for the optimization of microalga growth and ethanol production under laboratory conditions. The results showed that high specific growth rate and biomass productivity of 0.342 day⁻¹ and 0.497 g L⁻¹ day⁻¹ respectively, were achieved at high concentration of phosphate (0.115 g L⁻¹) and pH (9) at 21st day of cultivation. The elemental composition of optimized biomass has shown enhanced elemental accumulation of certain macro (C, O, P) and micronutrients (Na, Mg, Al, K, Ca and Fe) except for nitrogen and sulfur. The Fourier transform infrared spectroscopic analysis has revealed spectral peaks and high absorbance in spectral range of carbohydrates, lipids and proteins, in optimized biomass. The carbohydrates content of optimized biomass was observed as 58%, with 29.3 g L⁻¹ of fermentable sugars after acid catalyzed saccharification. The bioethanol yield was estimated as 51 % g ethanol/g glucose with maximum of 14.9 g/L of bioethanol production. In conclusion, it can be inferred that high specific growth rate and biomass productivity can be achieved by varying levels of phosphate concentration and pH during cultivation of Closteriopsis acicularis for improved yield of microbial growth, biomass and bioethanol production.     

Novel 2,4-dichlorophenoxy acetic acid substituted thiazolidin-4-ones as anti-inflammatory agents: Design,synthesis and biological screening

A library of fourteen 2-imino-4-thiazolidinone derivatives (1a-1n) has been synthesized and evaluated for in vivo anti-inflammatory activity and effect on ex-vivo COX-2 and TNF–α expression. Compounds 1k (5-(2,4-dichloro-phenooxy)-acetic acid (3-benzyl-4-oxo-thiazolidin-2-ylidene)-hydrazide) and 1m (5-(2,4-dichloro-phenooxy)-acetic acid (3-cyclohexyl-4-oxo-thiazolidin-2-ylidene)-hydrazide) exhibited in vivo inhibition of 81.14% and 78.80% respectively after 5 h in comparison to indomethacin which showed 76.36% inhibition of inflammation without causing any damage to the stomach. Compound 1k showed a reduction of 68.32% in the level of COX-2 as compared to the indomethacin which exhibited 66.23% inhibition of COX-2. The selectivity index of compound 1k was found to be 29.00 in comparison to indomethacin showing selectivity index of 0.476. Compounds 1k and 1m were also found to significantly suppress TNF-α concentration to 70.10% and 68.43% in comparison to indomethacin which exhibited 66.45% suppression.     

Biomass Yield and Nutrient Uptake of Energy Sorghum in Response to Nitrogen Fertilizer Rate on Marginal Land in a Semi-Arid Region

Energy sorghum tolerates adverse climatic and edaphic conditions and has great potential as biofuel feedstock in marginal land. This study investigates the potential energy sorghum biomass production and uptake of nitrogen (N), phosphorus (P), and potassium (K) on a sandy loam marginal land in a semi-arid region, in order to define optimum N fertilizer rate to produce the highest biomass yield with minimal nutrient elimination. Five N rate treatments (0, 60, 120, 180, and 240 kg ha^?1) and two sorghum varieties (sweet type Guotian-8 (GT-8) and biomass type Guoneng-11 (GN-11)) were used. Yield increment was observed as N level increased, but the standout treatment appeared to be N rate of 60 kg ha^?1 which significantly increased biomass yield vs. controls by 68.8% in 2014 and 64.1% in 2015. Biomass yield exhibited non-significant differences between N rate treatments from 60 to 240 kg ha^?1, although the highest biomass yield (9.2–11.9 t ha^?1) was observed in the 120 kg N ha^?1 treatment. Nutrient analysis showed that N, P, and K accumulation in aboveground plants increased with N rate increase, ranging between 32.2 and 119.1, 7.9 and 19.2, and 22.1 and 94.0 kg ha^?1, respectively, for the highest N rate of 240 kg ha^?1. Substantial amounts of N were extracted from the soil in control and 60 kg N ha^?1 treatments, despite the low fertility and organic matter content of the soil. Moreover, nitrogen (N) use efficiency (NUE) was maximized at lower N rates. A decline in physiological N use efficiency (PNUE) resulted in decreased agronomic N use efficiency (ANUE) at higher N rates. Hence, it is concluded that N fertilizer rate between 60 and 120 kg ha^?1 would be the optimal N requirement to facilitate sustainable production of energy sorghum on a sandy wasteland.     

Characterization of fusarium wilt-resistant and fusarium wilt-susceptible somaclones of banana cultivar rastali (Musa AAB) by random amplified polymorphic DNA and retrotransposon markers

Two DNA fingerprinting techniques, random amplified polymorphic DNA (RAPD) and inter-retrotransposon amplified polymorphism (IRAP), were used to characterize somaclonal variants of banana. IRAP primers were designed on the basis of repetitive and genome-wide dispersed long terminal repeat (LTR) retrotransposon families for assessing the somaclonal variation in 2Musa clones resistant and susceptible toFusarium oxysporum f. sp.cubense race 4. RAPD markers successfully detected genetic variation within and between individuals of the clones. IRAP makers amplified either by a single primer or a combination of primers based on LTR orientation successfully amplified different retrotransposons dispersed in theMusa genome and detected new events of insertions. RAPD markers proved more polymorphic than IRAP markers. Somaclonal variation seems to be the result of numerous indels occurring genome-wide accompanied by the activation of retroelements, as a result of stress caused by micropropagation. It is concluded that characterization of the somaclonal variants requires more than one DNA marker system to detect variation in diverse components of the genome.     

Preferential recognition of peroxynitrite modified human DNA by circulating autoantibodies in cancer patients

Peroxynitrite (ONOO⁻) has been vastly implicated in mutagenesis and cancer development. Present study probes the antigenicity of peroxynitrite damaged DNA (ONOO⁻-DNA) in cancer patients. Purified human placental DNA was damaged by the synergistic action of sodium nitroprusside (SNP) and Pyrogallol for 3 h at 37 °C. Binding characteristics of cancer autoantibodies as well as experimentally induced anti-peroxynitrite-DNA (anti-ONOO⁻-DNA) antibodies were assessed by ELISA and band shift assay. DNA modifications produced single strand breaks, decreased melting temperature (T_m), hyperchromicity in UV spectrum and decreased fluorescence intensity. The ONOO⁻-DNA induced high titre antibodies in experimental animals. Cancer autoantibodies exhibited enhanced binding with the modified DNA as compared to the native form. Lymphocyte DNA from cancer patients showed appreciable recognition of anti-ONOO⁻-DNA IgG as compared to the DNA from healthy subjects. The peroxynitrite modified DNA presents unique epitopes which may be one of the factors for the autoantibody induction in cancer patients.     

Removal and recovery of Cu(II) and Zn(II) using immobilized Mentha arvensis distillation waste biomass

The potential use of the immobilized Mentha arvensis distillation waste (IMADW) biomass for removal and recovery of Cu(II) and Zn(II) from aqueous was evaluated in the present study. Biosorption capacity of Cu(II) and Zn(II) on IMADW increased with increase in pH reaching a maximum at 5 for Cu(II) and 6 for Zn(II). The equilibrium sorption data agreed well with Langmuir isotherm model and pseudo-second-order kinetic model in batch mode. Cu(II) and Zn(II) uptake by IMADW was best described by pseudo-first-order kinetic model in continuous mode. Maximum Cu(II) and Zn(II) uptake by IMADW was 104.48 and 107.75 mg/g, respectively. Fourier Transform Infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were also carried out to investigate functional groups and surface changes of biomass. The results showed that IMADW biomass is a potential biomaterial to remove Cu(II) and Zn(II) ions with a high biosorption capacity from aqueous solutions.