Sulfur is in the Air: Cyanolichen Marriages and Pollution.

Cyanolichens are symbiotic organisms involving cyanobacteria and fungi (bipartite) or with the addition of an algal partner (tripartite). Cyanolichens are known for their heightened susceptibility to environmental pollution. We focus here on the impacts on cyanolichens due to rising air pollution; we are especially interested in the role of sulfur dioxide on cyanolichen biology. Cyanolichens due to air pollution including sulfur dioxide exposure, show symptomatic changes including degradation of chlorophyll, lipid membrane peroxidation, decrease in ATP production, changes in respiration rate, and alteration of endogenous auxins and ethylene production, although symptoms are known to vary with species and genotype. Sulfur dioxide has been shown to be damaging to photosynthesis but is relatively benign on nitrogen fixation which proposes as a hypothesis that the algal partner may be more in harm's way than the cyanobiont. In fact, the Nostoc cyanobiont of sulfur dioxide-susceptible Lobaria pulmonaria carries a magnified set of sulfur (alkane sulfonate) metabolism genes capable of alkane sulfonate transport and assimilation, which were only unraveled by genome sequencing, a technology unavailable in the 1950-2000 epoch, where most physiology- based studies were performed. There is worldwide a growing corpus of evidence that sulfur has an important role to play in biological symbioses including rhizobia-legumes, mycorrhizae-roots and cyanobacteria-host plants. Furthermore, the fungal and algal partners of L. pulmonaria appear not to have the sulfonate transporter genes again providing the roles of ambient-sulfur (alkanesulfonate metabolism etc.) mediated functions primarily to the cyanobacterial partner. In conclusion, we have addressed here the role of the atmospheric pollutant sulfur dioxide to tripartite cyanolichen viability and suggest that the weaker link is likely to be the photosynthetic algal (chlorophyte) partner and not the nitrogen-fixing cyanobiont.

Effect of acid modified tea-waste biochar on crop productivity of red onion (Allium cepa L.).

Biochar has widely been utilized as an agricultural soil amendment owing to its enhanced surface properties and cost-effectiveness. In the present work, the influence of tea waste biochar (TWBC) upon acid modification on Allium cepa L. (red onion) growth has been studied. Its effect as a soil amendment has also been studied by assessing the nutrient retention, microbial population growth and immobilization of potentially toxic metal ions. A greenhouse experiment was carried out by applying different biochar (BC) ratios (2% and 5% w/w) to soil as the growth media for onion plants. A 2.4 times (2.4 × ) reduction of phosphate from leaching was observed upon BC application at a ratio of 2% than that of 5%. Moreover, red onion plants that grew in the BC-fertilizer amended soil at a 2% ratio showed higher growth compared to that of 5%. A ∼1.3 × and ∼1.2 × increment of total dry weight was observed upon amendment of soil fertilizer system with nitric and sulfuric acid-modified TWBC, respectively. An analysis of the potentially toxic metal ion uptake by the respective plant parts showed that lead uptake by the roots of red onion was ∼8.3 × less in BC amended soil compared to that in contaminated soil. Thus, acid-modified TWBC can be considered a potential soil amendment for an enhanced red onion growth. Employing TWBC as a soil amendment in tropical countries, where tea-waste is in abundance, will boost sustainable agriculture.

Biochar based sorptive remediation of steroidal estrogen contaminated aqueous systems: A critical review.

Remediation of steroidal estrogens from aqueous ecosystems is of prevailing concern due to their potential impact on organisms even at trace concentrations. Biochar (BC) is capable of estrogen removal due to its rich porosity and surface functionality. The presented review emphasizes on the adsorption mechanisms, isotherms, kinetics, ionic strength and the effect of matrix components associated with the removal of steroidal estrogens. The dominant sorption mechanisms reported for estrogen were π-π electron donor-acceptor interactions and hydrogen bonding. Natural organic matter and ionic species were seen to influence the hydrophobicity of the estrogen in multiple ways. Zinc activation and magnetization of the BC increased the surface area and surface functionalities leading to high adsorption capacities. The contribution by persistent free radicals and the arene network of BC have promoted the catalytic degradation of adsorbates via electron transfer mechanisms. The presence of surface functional groups and the redox activity of BC facilitates the bacterial degradation of estrogens. The sorptive removal of estrogens from aqueous systems has been minimally reviewed as a part of a collective evaluation of micropollutants. However, to the best of our knowledge, a critique focusing specifically and comprehensively on BC-based removal of steroidal estrogens does not exist. The presented review is a critical assessment of the existing literature on BC based steroidal estrogen adsorption and attempts to converge the scattered knowledge regarding its mechanistic interpretations. Sorption studies using natural water matrices containing residue level concentrations, and dynamic sorption experiments can be identified as future research directions.

Draft Genome Sequence of Rhodococcus rhodochrous Strain ATCC 21198.

Rhodococcus rhodochrous is a Gram-positive red-pigmented bacterium commonly found in the soil. The draft genome sequence for R. rhodochrous strain ATCC 21198 is presented here to provide genetic data for a better understanding of its lipid-accumulating capabilities.