The repertoire of nitrogen assimilation in Rhodococcus: Catalysis, pathways and relevance in biotechnology and bioremediation

The Rhodococcus genus exhibits diverse enzymatic activity that can be exploited in the conversion of natural and anthropogenic nitrogenous compounds. This catalytic response provides a selective advantage in terms of available nutrients while also serving to remove otherwise harmful xenobiotics. This review provides a critical assessment of the literature on bioconversion of organo-nitrogen compounds with a consideration of applications in bioremediation and commercial biotechnology. By examining the major nitro-organic compounds (amino acids, amines, nitriles, amides and nitroaromatics) in turn, the considerable repertoire of Rhodococcus spp. is established. The available published enzyme reaction data is coupled with genomic characterisation to provide a molecular basis for Rhodococcus enzyme activity with an assessment of the cellular properties that aid substrate accessibility and ensure stability. The metabolic gene clusters associated with the observed reaction pathways are identified and future directions in enzyme optimisation and metabolic engineering are assessed. © 2014 Society of Chemical Industry.

Intellectual Property and Biotechnology: Biological Inventions

This book documents and evaluates the dramatic expansion of intellectual property law to accommodate various forms of biotechnology from micro-organisms, plants, and animals to human genes and stem cells. It makes a unique theoretical contribution to the controversial public debate over the commercialization of biological inventions. The author also considers the contradictions between the Supreme Court of Canada rulings in respect of the Harvard oncomouse, and genetically modified canola. He explores law, policy, and practice in both Australia and New Zealand in respect to gene patents and non-coding DNA. This study charts the rebellion against the European Union Biotechnology Directive – particularly in respect of Myriad Genetics’ BRCA1 and BRCA2 patents, and stem cell patent applications. The book also considers whether patent law will accommodate frontier technologies – such as bioinformatics, haplotype mapping, proteomics, pharmacogenomics, and nanotechnology. Intellectual Property and Biotechnology will be of prime interest to lawyers and patent attorneys, scientists and researchers, business managers and technology transfer specialists.

Fabrication and characterization of plasma polymer thin films from monoterpene alcohols for applications in organic electronics and biotechnology

After more than twenty years of basic and applied research, the use of nanotechnology in the design and manufacture of nanoscale materials is rapidly increasing, particularly in commercial applications that span from electronics across renewable energy areas, and biomedical devices. Novel polymers are attracting significant attention for they promise to provide a low−cost high−performance alternative to existing materials. Furthermore, these polymers have the potential to overcome limitations imposed by currently available materials thus enabling the development of new technologies and applications that are currently beyond our reach. This work focuses on the development of a range of new low−cost environmentally−friendly polymer materials for applications in areas of organic (flexible) electronics, optics, and biomaterials. The choice of the monomer reflects the environmentally−conscious focus of this project. Terpinen−4−ol is a major constituent of Australian grown Melaleuca alternifolia (tea tree) oil, attributed with the oil's antimicrobial and anti−inflammatory properties. Plasma polymerisation was chosen as a deposition technique for it requires minimal use of harmful chemicals and produces no hazardous by−products. Polymer thin films were fabricated under varied process conditions to attain materials with distinct physico−chemical, optoelectrical, biological and degradation characteristics. The resultant materials, named polyterpenol, were extensively characterised using a number of well−accepted and novel techniques, and their fundamental properties were defined. Polyterpenol films were demonstrated to be hydrocarbon rich, with variable content of oxygen moieties, primarily in the form of hydroxyl and carboxyl functionalities. The level of preservation of original monomer functionality was shown to be strongly dependent on the deposition energy, with higher applied power increasing the molecular fragmentation and substrate temperature. Polyterpenol water contact angle contact angle increased from 62.7° for the 10 W samples to 76.3° for the films deposited at 100 W. Polymers were determined to resist solubilisation by water, due to the extensive intermolecular and intramolecular hydrogen bonds present, and other solvents commonly employed in electronics and biomedical processing. Independent of deposition power, the surface topography of the polymers was shown to be smooth (Rq <0.5 nm), uniform and defect free. Hardness of polyterpenol coatings increased from 0.33 GPa for 10 W to 0.51 GPa for 100 W (at 500 μN load). Coatings deposited at higher input RF powers showed less mechanical deformation during nanoscratch testing, with no considerable damage, cracking or delamination observed. Independent of the substrate, the quality of film adhesion improved with RF power, suggesting these coatings are likely to be more stable and less susceptible to wear. Independent of fabrication conditions, polyterpenol thin films were optically transparent, with refractive index approximating that of glass. Refractive index increased slightly with deposition power, from 1.54 (10 W) to 1.56 (100 W) at 500 nm. The optical band gap values declined with increasing power, from 2.95 eV to 2.64 eV, placing the material within the range for semiconductors. Introduction of iodine impurity reduced the band gap of polyterpenol, from 2.8 eV to 1.64 eV, by extending the density of states more into the visible region of the electromagnetic spectrum. Doping decreased the transparency and increased the refractive index from 1.54 to 1.70 (at 500 nm). At optical frequencies, the real part of permittivity (k) was determined to be between 2.34 and 2.65, indicating a potential low-k material. These permittivity values were confirmed at microwave frequencies, where permittivity increased with input RF energy – from 2.32 to 2.53 (at 10 GHz ) and from 2.65 to 2.83 (at 20 GHz). At low frequencies, the dielectric constant was determined from current−voltage characteristics of Al−polyterpenol−Al devices. At frequencies below 100 kHz, the dielectric constant varied with RF power, from 3.86 to 4.42 at 1 kHz. For all samples, the resistivity was in order of 10⁸−10⁹ _m (at 6 V), confirming the insulating nature of polyterpenol material. In situ iodine doping was demonstrated to increase the conductivity of polyterpenol, from 5.05 × 10⁻⁸ S/cm to 1.20 × 10⁻⁶ S/cm (at 20 V). Exposed to ambient conditions over extended period of time, polyterpenol thin films were demonstrated to be optically, physically and chemically stable. The bulk of ageing occurred within first 150 h after deposition and was attributed to oxidation and volumetric relaxation. Thermal ageing studies indicated thermal stability increased for the films manufactured at higher RF powers, with degradation onset temperature associated with weight loss shifting from 150 ºC to 205 ºC for 10 W and 100 W polyterpenol, respectively. Annealing the films to 405 °C resulted in full dissociation of the polymer, with minimal residue. Given the outcomes of the fundamental characterisation, a number of potential applications for polyterpenol have been identified. Flexibility, tunable permittivity and loss tangent properties of polyterpenol suggest the material can be used as an insulating layer in plastic electronics. Implementation of polyterpenol as a surface modification of the gate insulator in pentacene-based Field Effect Transistor resulted in significant improvements, shifting the threshold voltage from + 20 V to –3 V, enhancing the effective mobility from 0.012 to 0.021 cm²/Vs, and improving the switching property of the device from 10⁷ to 10⁴. Polyterpenol was demonstrated to have a hole transport electron blocking property, with potential applications in many organic devices, such as organic light emitting diodes. Encapsulation of biomedical devices is also proposed, given that under favourable conditions, the original chemical and biological functionality of terpinen−4−ol molecule can be preserved. Films deposited at low RF power were shown to successfully prevent adhesion and retention of several important human pathogens, including P. aeruginosa, S. aureus, and S. epidermidis, whereas films deposited at higher RF power promoted bacterial cell adhesion and biofilm formation. Preliminary investigations into in vitro biocompatibility of polyterpenol demonstrated the coating to be non−toxic for several types of eukaryotic cells, including Balb/c mice macrophage and human monocyte type (HTP−1 non-adherent) cells. Applied to magnesium substrates, polyterpenol encapsulating layer significantly slowed down in vitro biodegradation of the metal, thus increasing the viability and growth of HTP−1 cells. Recently, applied to varied nanostructured titanium surfaces, polyterpenol thin films successfully reduced attachment, growth, and viability of P. aeruginosa and S. aureus.

Biotechnology in the development of improved phytases

Phytase enzyme supplements are now ubiquitous in the commercial production of a range of livestock, particularly chickens and pigs. Significant effort has been directed over the last two decades towards producing improved enzymes with higher activity, increased stability and at economic levels in industrial fermentations. As such, there are excellent products on the market, but there is a continuing demand for further improvements to drive down costs and for enzyme manufacturers to increase market share. The rapid development of DNA sequencing and gene synthesis technologies has provided ready access to a large number of new and uncharacterised potential phytases. Challenges remain however in identifying and developing those with improved properties.

Research productivity levels of Chinese TEFL academics

Since China’s Economic Reform and its Open Door Policy, China has entered a new era of education (Adamson, 2002; Hu, 2005a). English has gained status as a language for international relations (Graddol, 1997) and international trade (Qu, 2007). Hence, in 2001, China’s Ministry of Education (MOE) required universities to offer 5-10% of their course units in English, particularly in the fields of information technology, biotechnology, finance and law (Jen, 2001; MOE, 2001). However, “the upgrading of national English proficiency, then, is predicted largely on the professional competence of the teaching force” (Hu, 2005b, p. 655). For TEFL academics, one component of this competence is the capacity to conduct research (Day, 1991; Shu, 2002). Indeed, research productivity has become essential for university success, and academics’ employment and promotional prospects. This study aims to investigate 182 Chinese TEFL academics’ research outputs across three Chinese higher education institutions through the research question: What are the research productivity levels of Chinese TEFL academics? A survey instrument was devised to gather TEFL academics’ calculations of research productivity and, in particular, the quality and quantity of research outputs over a five-year period (2004-2008). Descriptive statistics through SPSS were used to analyse data across research output fields (e.g., journal articles, conference papers). Academic status varied (n=182; teaching assistants 23.6%, lecturers 47.3%, associate professors 22.5%, and professors 6.6%) as did years of teaching (1-5 years 27.4%, 6-10 years 24.7%, 11-15 18.1%, 16-20 years 13.7%, > 21 years 15.9%). Results (n=182, male=27%, females=73%) indicated 18% had not produced any research in the five-year period. Indeed, more than 70% had produced no research in all categories except non-core journal articles and provincial projects. An overwhelming majority of TEFL academics had zero productivity in 10 of the 12 categories. Nevertheless, there were highly-productive TEFL academics, who had produced five or more pieces of research across the 12 categories. In addition, there was not much difference between sole and co-authored research outputs, except non-core journal articles where sole authored work was 20% higher than co-authored work. China’s desire for international competitiveness in education will require measures that facilitate higher levels of research productivity. These measures must include professional development, support and mentoring programs, and employment of personnel who can guide these processes. Research performance is an outcome, hence there is a need to understand Chinese TEFL academics’ perceptions about research, and experiences that may hinder and facilitate higher research productivity.

Ethyl-eicosapentaenoic acid in first-episode psychosis : a 1H-MRS study

Ethyl-eicosapentaenoic acid (E-EPA) is an omega-3 fatty acid that has been used in a range of neuropsychiatric conditions with some benefits. However, its mechanism of action is unknown. Here, we investigate its effects on in vivo brain metabolism in first-episode psychosis (FEP). Proton magnetic resonance spectroscopy at 3 T was performed in the temporal lobes of 24 FEP patients before and after 12 weeks of treatment in the context of a larger double-blind, placebo-controlled E-EPA augmentation study. Treatment group effects for glutathione (F1,12=6.1, p=0.03), and a hemisphere-by-group interaction for glutamine/glutamate (F1,20=4.4, p=0.049) were found. Glutathione increased bilaterally and glutamate/glutamine increased in the left hemisphere following E-EPA administration. Improvement in negative symptoms correlated with metabolic brain changes, particularly glutathione (r=-0.57). These results suggest that E-EPA augmentation alters glutathione availability and modulates the glutamine/glutamate cycle in early psychosis, with some of the metabolic brain changes being correlated with negative symptom improvement. Larger confirmatory studies of these postulated metabolic brain effects of E-EPA are warranted.

Towards Humane Technologies: Biotechnologies, New Media and Ethics

What are the ethical and political implications when the very foundations of life —things of awe and spiritual significance — are translated into products accessible to few people? This book critically analyses this historic recontextualisation. Through mediation — when meaning moves ‘from one text to another, from one discourse to another’ — biotechnology is transformed into analysable data and into public discourses. The unique book links biotechnology with media and citizenship. As with any ‘commodity’, biological products have been commodified. Because enormous speculative investment rests on this, risk will be understated and benefit will be overstated. Benefits will be unfairly distributed. Already, the bioprospecting of Southern megadiverse nations, legally sanctioned by U.S. property rights conventions, has led to wealth and health benefits in the North. Crucial to this development are biotechnological discourses that shift meanings from a “language of life” into technocratic discourses, infused with neo-liberal economic assumptions that promise progress and benefits for all. Crucial in this is the mass media’s representation of biotechnology for an audience with poor scientific literacy. Yet, even apparently benign biotechnology spawned by the Human Genome Project such as prenatal screening has eugenic possibilities, and genetic codes for illness are eagerly sought by insurance companies seeking to exclude certain people. These issues raise important questions about a citizenship that is founded on moral responsibility for the wellbeing of society now and into the future. After all, biotechnology is very much concerned with the essence of life itself. This book provides a space for alternative and dissident voices beyond the hype that surrounds biotechnology.

Improving taro (Colocasia esculenta var. esculenta) production using biotechnological approaches

Taro (Colocasia esculenta L. Schott) is an important crop worldwide but is of particular significance in many Pacific Island countries where it forms part of the staple diet and serves as an export commodity. Escalating pest and disease problems are jeopardizing taro production with serious implications to food security and trade. Biotechnological approaches to addressing pest and disease problems, such as somatic embryogenesis and transgenesis, are potentially viable options. However, despite biotechnological advancements in higher profile agronomic crops, such progress in relation to Colocasia esculenta var. esculenta has been slow. This paper reviews taro biology, highlights the cultural and economic significance of taro in Pacific Island countries and discusses the progress made towards the molecular breeding of this important crop to date.

Can tissue engineering concepts advance tumor biology research?

Advances in tissue engineering have traditionally led to the design of scaffold- or matrix-based culture systems that better reflect the biological, physical and biochemical environment of the natural extracellular matrix. Although their clinical applications in regenerative medicine tend to receive most of the attention, it is obvious that other areas of biomedical research could be well served by the powerful tools that have already been developed in tissue engineering. In this article, we review the recent literature to demonstrate how tissue engineering platforms can enhance in vitro and in vivo models of tumorigenesis and thus hold great promise to contribute to future cancer research.