John A. Glaser

Fate of pentachlorophenol (PCP) in sterile soils inoculated with the white-rot basidiomycete Phanerochaete chrysosporium: Mineralization, volatilization and depletion of PCP

Abstract The fate of pentachlorophenol (PCP) in three sterile soils inoculated with a white-rot basidiomycete, Phanerocaete chrysosporium , was investigated. Mineralization and volatilization of PCP and its transformation products and residual PCP concentration were measured for 2-months from soil microcosms inoculated with P. chrysosporium or left non-inoculated. There was a dramatic decrease (ave. decrease 98%) in the cxtractable PCP concentration in inoculated soils compared to that in non-inoculated soils (ave. decrease 43%). In the three inoculated soils, the greatest loss of PCP was during the first week. Initial rates of PCP depletion varied by soil. Differences among these soils in quantities of soil nutrients available for fungal growth, particularly carbon and nitrogen, may have been indirectly responsible for the differences by influencing the rates of soil colonization. Pentachlorophenol mineralized or evolved as volatile products was slight in the three soils. Our results suggest that P. chrysosporium removes PCP per se from soils primarily by converting it to non-volatile products. The nature of the products, whether they arc cxtractable or soil-bound, is greatly influenced by soil type.

Treatment of a pentachlorophenol- and creosote-contaminated soil using the lignin-degrading fungus phanerochaete sordid a: A field demonstration

The feasibility of large-scale fungal bioaugmentation was evaluated by assessing the ability of the lignin-degrading fungus Phanerochaete sordida to decrease the soil concentrations of pentachlorophenol (PCP) and 13 priority pollutant polynuclear aromatic (PNA) creosote components in a field-demonstration study. Inoculation of the contaminated soil with the fungus (fungal treatment) at a rate of 10% (dry wt fungal hyphae and inoculum substrate dry wt soil−1) was compared to amending the soil (amended control) with sterile inoculum substrate also at a 10% rate (dry wt substrate dry wt soil−1) and no treatment (non-amended control), for their effects on PCP and PNA concentrations over 20 wk. The initial soil PCP and total measured PNA concentrations for the three treatments averaged 1058 and 1210mg kg−1, respectively. Despite very low initial amounts of fungal biomass, determined from ergosterol concentrations in the inoculum and inoculated soil, there was a 64% PCP decrease to a residual concentration of 362 mg kg−1 in the fungal-treated soil after 20 wk of treatment. This residual concentration was statistically less than the 715 mg kg−1 (26% decrease) and the 985 mg kg−1 (18% decrease) PCP concentrations observed in the amended control and the non-amended control soils, respectively. There were significant decreases in the concentrations of 3- and 4-ring PNAs in all treatments. With the exception of acenapthene, decreases in the concentrations of 3-ring PNAs were significantly greater in the non-amended control soil than in either the amended control or fungal-treated soils. Conversely, decreases in the concentration of 4-ring PNAs tended to be greater in the fungal-treated and amended control soils than in the non-amended control soils. The concentrations of 5- and 6-ring PNAs were not decreased significantly by any of the treatments.

Use of Spectral Vegetation Indices Derived from Airborne Hyperspectral Imagery for Detection of European Corn Borer Infestation in Iowa Corn Plots

Abstract Eleven spectral vegetation indices that emphasize foliar plant pigments were calculated using airborne hyperspectral imagery and evaluated in 2004 and 2005 for their ability to detect experimental plots of corn manually inoculated with Ostrinia nubilalis (Hübner) neonate larvae. Manual inoculations were timed to simulate infestation of corn, Zea mays L., by first and second flights of adult O. nubilalis. The ability of spectral vegetation indices to detect O. nubilalis-inoculated plots improved as the growing season progressed, with multiple spectral vegetation indices able to identify infested plots in late August and early September. Our findings also indicate that for detecting O. nubilalis-related plant stress in corn, spectral vegetation indices targeting carotenoid and anthocyanin pigments are not as effective as those targeting chlorophyll. Analysis of image data suggests that feeding and stem boring by O. nubilalis larvae may increase the rate of plant senescence causing detectable differences in plant biomass and vigor when compared with control plots. Further, we identified an approximate time frame of 5–6 wk postinoculation, when spectral differences of manually inoculated “second” generation O. nubilalis plots seem to peak.

White Rot Fungi in the Treatment of Hazardous Chemicals and Wastes

Microbiological treatment of hazardous wastes has generally been associated with the use of bacteria. However, during the past decade a significant body of evidence has accumulated that demonstrates that fungi, in particular lignin-degrading or white-rot fungi, have the ability to degrade a wide range of hazardous organic compounds and thus might also be useful for treatment of materials contaminated with these compounds.

Green chemistry with nanocatalysts

Nano matter is expected to be a fruitful area for green chemistry catalysis due the increasing ability to design in the nano state and the high surface areas found in nano materials. Nanocatalysts are esteemed as materials of enormous surface areas and with new research, developments may offer expanding catalytic capabilities. The iron catalyst BASF-S6-10 has recently been developed for application in the Haber–Bosch ammonia synthesis process. With a surface area of 20 m/g, the catalyst is deployed as nanometer-sized particles containing reduced iron oxide in a framework of Al2O3 and CaO to stabilize the catalyst against agglomerization.

Multistep organic synthesis using flow chemistry

The technology enabling synthetic chemistry within flow systems has been advanced through remarkable synthetic designs using multistep sequences to conduct synthetic schemes leading to products of high complexity. Continuous flow reactors provide a synthetic platform for the combination of several chemical transformations as a single process. This synthetic strategy enables the chemist to organize multiple flow reactors in sequence where the reaction intermediates are not isolated but passed onto the next reactor component of the sequence. Each stream requires flow rate optimization to sustain required residence times and temperature effects for each reactor. Single reactors can be optimized for the reaction conditions conducted within the reactor but the situation becomes more complex when one reactor precedes another in sequence. Conditions are required to support each synthetic stage and a single reactor cannot be optimized by itself. The fine balance of conditions can lead to success or failure of such a flow system. By-products can be removed in-line through the use of phase-bound scavenging reagents. These small flow reactors have been shown to enable the use of unstable intermediates such as acyl azides formed as part of the Curtius rearrangement. The simplicity of the reactor sequence permits consideration of splitting synthetic sequences to permit the desired reaction control. An example of multistep synthesis is shown for the neolignin natural product grossamide. A system of three independent pumps delivering reactants through a series of valves using in-line monitoring and feedback control was operated under computer control.

Microplastics in the environment

Plastic pollution has been estimated to be composed of more than 5 trillion plastic pieces equal to some 250,000 tons in the global seas. A United Nations advisory body: Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) recently released a 98 page report: Sources, Fate and Effects of Microplastics in the Marine Environment: a Global Assessment, which asserts that microplastics can have major detrimental effects on marine life based on 5 years of study. Microplastics for this report are characterized as fragments of plastics having dimensions of 1 nm to \5 mm in diameter capable of damaging marine life comparable to larger floating plastics debris. Microplastics are spread throughout consumer items ranging from abrasives to cosmetics. This report aspires to inform a potential problem that is poorly understood at global scale. The major sources of the ocean pollution are currently being identified with little knowledge of the fate and effects of microplastics in the ocean. The presence of plastics in the ocean must receive greater monitoring and control to avoid what is considered potential environmental disasters. One detrimental effect of microplastics could be the conveyance of absorbed pesticides or other toxic materials to susceptible organisms leading to cellular damage. The report found that information and data related to microplastics were highly variable and poorly quantified. A search for hotspots on land and in the sea could greatly aid the analysis of the environmental effects of microplastics. The report advocates control of plastic pollution on land before it becomes a water pollution issue. Environ. Pollut. 2014, 188, 177–181; Environ. Sci. Technol. 2014, 48, 4732–4738; Proc. Natl. Acad. Sci. U.S.A. 2014, 111, 10239–10244; PLOS ONE 2014, 9, e111913; Science 2014, 345, 6193, 144–145; Science 2015, 347, 6223, 768–771; http://www.gesamp.org/data/ gesamp/files/media/Publications/Reports_and_studies_90/ gallery_2230/object_2461_large.pdf ; GESAMP ‘‘Sources, fate and effects of microplastics in the marine environment: a global assessment’’ (Kershaw, P. J., ed.). (IMO/FAO/ UNESCO-IOC/UNIDO/WMO/IAEA/UN/UNEP/UNDP Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection). Rep. Stud. GESAMP 2015, No. 90, 96 p.

Good chemical manufacturing process criteria

A tenfold increase in R&D expenditures has been experienced by research-based pharmaceutical companies over the past 25 years. It is incumbent upon these producers to find ways to reduce manufacturing costs. One approach that uses innovative developments leads to targeted product structures and workflow has been assembled by contributors from Boehringer Ingelheim Pharma & Pharmaceuticals. A series of eight criteria: material cost, process efficiency, yield, volume-time-output (VTO), environmental factor (E factor/process mass intensity), quality service level, process excellence index, and modified EcoScale were found to greatly support cost-saving efforts. Many of these components have received extensive attention in the literature. The individual contributions of the criteria to the chemical process development offer a significant aid to query each stage of synthetic development for improved good manufacturing practice. For instance synthetic planning in a linear format can be improved through considerations of convergent synthetic approaches to the target chemical. A highly useful EcoScale template accompanies the article to permit an understanding of the analysis at a glance. A weighting factor scheme for the use of the eight criteria for a good chemical process is offered to facilitate the overall analysis. Criteria weighting is expected to change for different process optimization objectives and economic priorities. Org Process Res Dev 2012, 16, 1697–1706.

New plastic recycling technology

Greater than 60% of the total plastic content of municipal solid waste is comprised of polyolefins (low-density, highdensity, and linear polyethylene and polypropylene. Polyethylene (PE) is the largest volume component but presents a challenge due to the absence of low-energy degradation processes. A recent research report offers a candidate chemistry to fill the needs of a new process. Utilizing tandem catalytic cross-alkane metathesis (CAM) process, researchers have shown that polyethylenes can be degraded under mild reaction conditions using an iridium catalyst as outlined in the following scheme:

Synthetic biology leading to specialty chemicals

Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate production pathways to a wide variety of chemicals generated by microorganisms. The selection and enhancement of microbiological strains through the practice of strain engineering enables targets of design, construction, and optimization. Pathway analysis leads to a comprehension of how chemicals can be produced by these novel synthetic systems. New synthetic biology tools provide an assessment of the current developments leading to commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. A synthetic biology toolbox offers a means to harness the essential capacity of organisms by diverting metabolic resources into the production of diverse and renewable specialty chemicals. The field is quickly shifting from a paradigm of increasing endogenous production which has dominated the field. Currnetly, simple discovery offers the opportunity to identify pathways contributing to a new paradigm marked by fully, rationally designed circuits and synthetically designed/optimized pathways. Recent developments of biotechnological techniques and models directed to the understanding and manipulation of metabolism and gene expression are summarized. These synthetic biology tools are organized according to their primary function: for the design, the construction, or the optimization of a pathway. The importance of these tools can be demonstrated for their contribution to the production of chemicals and has identified a diverse set of organisms to be exploited by the application of metabolic engineering. Monomers such as styrene have been identified as candidates for new technology development due to their intensive energy requirement for production. A de novo synthetic design utilizes a novel metabolic pathway using glucose as a renewable feedstock. Deriving polymers and copolymers directly from microorganisms becomes possible. Polylactic acid (PLA) having low toxicity to humans and high biocompatibility is a well-known macromolecular, biodegradable target. Recent research shows PLA to be available from an E. coli strain with a molecular weight of 141,000 Da at a titer of 20 g/L.