Effect of 1-methyl-3-octyleimmidazolium chloride on the stability and activity of lysozyme: a spectroscopic and molecular dynamics studies

Herein, the binding of 1-methyl-3-octylimidazolium chloride [OMIM][Cl] ionic liquid with hen egg white lysozyme (HEWL) has been studied using fluorescence, time resolved fluorescence, UV–visible and circular dichroism (CD) spectroscopy, in combination with computational study. The fluorescence results revealed that [OMIM][Cl] quenches the fluorophore of HEWL through static quenching mechanism. The calculated thermodynamic parameters show that [OMIM][Cl] bind with HEWL through hydrophobic interactions. In addition, the negative value of Gibbs energy change (?G) indicates that the binding process was spontaneous. Furthermore, UV–vis and CD results indicate that [OMIM][Cl] induce the conformational change in HEWL and increase its enzymatic activity. Additionally, molecular docking results showed that [OMIM][Cl] binds at the active site of HEWL where both the fluorophore residues (Trp108 and Trp62) and the catalytic residues (Glu35 and Asp52) reside. Molecular dynamic simulation results show the reduction of intra-molecular hydrogen bond of HEWL when it binds with [OMIM][Cl].     

Screening of IR50?×?Rathu Heenati F7 RILs and Identification of SSR Markers Linked to Brown Planthopper (Nilaparvata lugens St?l) Resistance in Rice (Oryza sativa L.)

Brown planthopper (Nilaparvata lugens St?l) is one of the major insect pests of rice. A Sri Lankan indica rice cultivar Rathu Heenati was found to be resistant to all biotypes of the brown planthopper. In the present study, a total of 268 F₇ RILs of IR50 and Rathu Heenati were phenotyped for their level of resistance against BPH by the standard seedbox screening test (SSST) in the greenhouse. A total of 53 SSR primers mapped on the chromosome 3 were used to screen the polymorphism between the parents IR50 and Rathu Heenati, out of which eleven were found to be polymorphic between IR50 and Rathu Heenati. The eleven primers that have shown polymorphism between the IR50 and Rathu Heenati parents were genotyped in a set of five resistant RILs and five susceptible RILs along with the parents for co-segregation analysis. Among the eleven primers, two primers namely RM3180 (18.22 Mb) and RM2453 (20.19 Mb) showed complete co-segregation with resistance. The identification of SSR markers linked with BPH resistant could be used for the maker assisted selection (MAS) program in rice breeding and to map the resistant genes on rice chromosomes for further gene cloning.     

Biosorption of anionic textile dyes by nonviable biomass of fungi and yeast

The nonviable biomass of Aspergillus niger, Aspergillus japonica, Rhizopus nigricans, Rhizopus arrhizus, and Saccharomyces cerevisiae were screened for biosorption of textile dyes. The selected anionic reactive dyes were C.I. Reactive Black 8, C.I. Reactive Brown 9, C.I. Reactive Green 19, C.I. Reactive Blue 38, and C.I. Reactive Blue 3. Experiments were conducted at initial dye concentration of 50, 100, 150 and 200mg/L. The effect of initial dye concentration, dose of biosorbent loading, temperature, and pH on adsorption kinetics was studied. S. cerevisiae and R. nigricans were good biosorbents at initial dye concentration of 50mg/L, 1g% (w/v) biomass loading and 29+/-1 degrees C. R. nigricans adsorbed 90-96% dye in 15min, at 20 degrees C and pH 6.0. The data showed an optimal fit to the Langmuir and Freundlich isotherms. The maximum uptake capacity (Q(o)) for the selected dyes was in the range 112-204mg/g biomass.     

From bacterial genomics to metagenomics: concept,tools and recent advances

In the last 20 years, the applications of genomics tools have completely transformed the field of microbial research. This has primarily happened due to revolution in sequencing technologies that have become available today. This review therefore, first describes the discoveries, upgradation and automation of sequencing techniques in a chronological order, followed by a brief discussion on microbial genomics. Some of the recently sequenced bacterial genomes are described to explain how complete genome data is now being used to derive interesting findings. Apart from the genomics of individual microbes, the study of unculturable microbiota from different environments is increasingly gaining importance. The second section is thus dedicated to the concept of metagenomics describing environmental DNA isolation, metagenomic library construction and screening methods to look for novel and potentially important genes, enzymes and biomolecules. It also deals with the pioneering studies in the area of metagenomics that are offering new insights into the previously unappreciated microbial world. The authors have contributed equally to the work     

Secretion of ligninperoxidase by Penicillium citrinum,Fusarium oxysporum and Aspergillus terreus

Secretion of ligninperoxidase [E.C.1.11.1.7] by Penicillium citrinum, Fusarium oxysporum and Aspergillus terreus in liquid culture growth medium has been demonstrated. Enzymatic characteristics like Km, pH and temperature optima using veratryl alcohol as the organic substrate of ligninperoxidases from above sources have been determined. Km values using veratryl alcohol as substrate for enzymes from P. citrinum, F. oxysporum and A. terreus were 69, 64 and 60 microM respectively. Km values using H2O2 as the variable substrate were 64, 72 and 80 microM.The pH optima were 4.0, 2.3 and 2.0 respectively. The values of temperature optima were 30 degrees, 25 degrees and 22 degrees C for the enzymes from P. citrinum, F. oxysporum and A. terreus respectively.     

Assessment of heavy metal in the water,sediment, and two edible fish species of Jamshedpur Urban Agglomeration,India with special emphasis on human health risk

The city of Jamshedpur, nicknamed the “industrial capital of Jharkhand,” is one of the oldest industrial settlements in India, nestled amidst the mineral-rich Chota Nagpur plateau, with its diverse tribal population. Heavy metal contamination from industrialization and urbanization can pose a serious health risk to the resident population of the city. Metal concentrations in water and sediment of various water bodies (rivers, canals, and lakes) were determined using ICP-MS. Pollution indices indicate heavy metal contamination at Jamshedpur Urban Agglomeration, mainly because of Cr (23–1111.6 mg/kg), Hg (0.08–4.11 mg/kg), and Pb (5.2–248 mg/kg). Labeo rohita and Punitus sarara, the two popular edible fishes, also have high concentration of Cr, Hg, and Pb. Health risk to human population due to consumption of metal contaminated edible fishes (L. rohita and P. sarara) was determined by target hazard quotient (THQ) and hazard index (HI). THQ value of fish consumption (most popular protein supplement in the area) was found higher for Cr and Pb when compared with previous literature on fish consumption. Also, HI value ranged from 1.4 to 3.9, suggesting that the children have higher health risks than adults, due to consumption of metal contaminated fishes (especially L. rohita).     

Physiological responses of carbon-sequestering microalgae to elevated carbon regimes

In order to identify a high carbon-sequestering microalgal strain, the physiological effect of different concentrations of carbon sources on microalgae growth was investigated. Five indigenous strains (I-1, I-2, I-3, I-4 and I-5) and a reference strain (I-0: Coccolithus pelagicus 913/3) were subjected to CO₂ concentrations of 0.03–15% and NaHCO₃ of 0.05–2 g CO₂ l^–1. The logistic model was applied for data fitting, as well as for estimation of the maximum growth rate (μ_max) and the biomass carrying capacity (B_max). Amongst the five indigenous strains, I-3 was similar to the reference strain with regards to biomass production values. The B_max of I-3 significantly increased from 214 to 828 mg l^–1 when CO₂ concentration was increased from 0.03 to 15% (r = 0.955, P = 0.012). Additionally, the B_max of I-3 increased with increasing NaHCO₃ (r = 0.885, P = 0.046) and was recorded at 153 mg l^–1 (at 0.05 g CO₂ l^–1) and 774 mg l^–1 at (2 g CO₂ l^–1). Relative electron transport rate (rETR) and maximum quantum yield (F_v/F_m) were also applied to assess the impact of elevated carbon sources on the microalgal cells at the physiological level. Isolate I-3 displayed the highest rETR confirming its tolerance to higher quantities of carbon. Additionally, the decline in F_v/F_m with increasing carbon was similar for strains I-3 and the reference strain. Based on partial 28s ribosomal RNA gene sequencing, strain I-3 was homologous to the ribosomal genes of Chlorella sp.     

Hepatic and renal phosphomonoesterases and adenosine triphosphatases in chronic hyperprolactinaemic rats.

Influence of hyperprolactinaemia, induced endogenously by anterior pituitary transplantation on rat hepatic and renal cortical and medullary phosphomonoesterases and adenosine triphosphatases (ATPases) has been investigated. Although prolactin has a stimulatory effect on phosphomonoesterases and ATPases, it exhibits a specific and temporal influence on each subtype of hepatic and renal ATPases and phosphomonoesterases at different durations of pituitary transplantation. The specific activities of alkaline phosphatase and Na(+)-K+ dependent ATPases are activated in all the regions of different durations of experimentation. However, acid phosphatases, Ca2+ and Mg2+ dependent ATPases exhibit a differential response to prolactin in renal cortex, medulla and liver. Direct influence of prolactin on hepatic and renal phosphomonoesterases and ATPases is thus suggested.