IN SITU SEPARATION OF ETHANOL WITH AQUEOUS TWO-PHASE SYSTEM AND ASSESSMENT OF KLa FOR YEAST GROWTH IN BATCH CULTIVATION

In the fermentation process, the separation of product and its purification is the most difficult and exigent task in the ground of biochemical engineering. Another major problem that is encountered in the fermentation is product inhibition, which leads to low conversion and low productivities. Extractive fermentation is a technique that helps in the in situ removal of product and better performance of the fermentation. An aqueous two-phase system was employed for in situ ethanol separation since the technique was biofriendly to the Saccharomyces cerevisiae and the ethanol produced. The two-phase system was obtained with polyethylene glycol 4000 (PEG 4000) and ammonium sulfate in water above critical concentrations, with the desire that the ethanol moves to the top phase while cells rest at the bottom. The overall mass transfer coefficient (K_La) was also estimated for the yeast growth at different rpm. The concentration and yield of ethanol were determined for conventional fermentation to be around 81.3% and for extractive fermentation around 87.5% at the end of the fermentation. Based on observation of both processes, extractive fermentation was found to be the best.     

SongMakers: An industry-led approach to arts partnerships in education

Reported benefits of arts partnerships with schools range from improvements in students' motivation and engagement in learning to teachers' increased confidence in teaching the arts, and strengthened school and community relationships. Yet, in the scholarship on arts partnerships to date, limited critical attention has been given to the impact of programs primarily driven by government supported industry-based imperatives. There may be legitimate concerns that, in primarily servicing economic or employment needs, industry–school partnerships overlook social and interpersonal aspects of learning in favor of goal-orientated skills training to meet “the market.” This article informs arts education policy and industry directions by acknowledging this concern and reporting on the outcomes of an industry–schools partnership where industry “training” appears to be leveraging a number of more holistic student learning outcomes. Jointly funded by industry and government, SongMakers is an Australian artist in residence program that aims to improve the export potential of Australia's contemporary music industry and contribute to the implementation of a contemporary music curriculum. It involves professional songwriters and producers with international recording experience working as mentors to students who create and produce new music in intensive two-day workshops. This article outlines how the program is demonstrating emergent positive impact not only on students' music knowledge and skill development, and understanding of the contemporary music industry, but on engagement, confidence in learning, and self-efficacy. It does not argue that all industry programs can or will achieve such impacts, but that diverse kinds of arts partnerships in schools can contribute to a viable ecology of quality educational practice in the arts.     

Spatial distribution of toxic metals in drinking water sources and their associated health risk in district buner,Northern Pakistan

Vigorous knowledge on the occurrence and distribution of toxic metals (TMs) in theenvironment is needed to assess their toxicological impacts on human health especially in developing countries like Pakistan. For the first time, the concentrations of TMs like Ni, Zn, Pb, Cr, and Cd in both ground and surface water and their potential health risk in the district Buner (Pakistan) were determined using Inductive Coupled Plasma Mass Spectrometry (ICP-MS, Agilent Technologies, 7500 CX, USA) and their results were compared with their safe limits defined by Pakistan Environmental Protection Agency (Pak-EPA) and World Health Organization WHO (2008 WHO (World Health Organization). 2008. Guidelines for drinking water quality, First Addendum to third ed. Recommendations, vol 1. Geneva, Switzerland [Google Scholar]). The concentrations of TMs, like Pb (43% and 86%), Ni (63% and 32%), Cr (41%), and Cd (1% and 20%) in drinking water samples exceeded their respective permissible limits set by Pak-EPA and WHO (2008), respectively. The mean concentrations of TMs were found in decreasing order Ni > Pb > Cr > Cd > Zn. The HRI values of TMs in drinking water samples for both adults and children were observed <1 indicating no health risk to the local population. Excessive marble industries are present in the study area; therefore, it is necessary to reduce metal contamination via proper disposal and treatment of marble wastewater, for which the government should take serious action in the study area.     

Biosurfactants and aqueous two-phase fermentation

The partition of surfactants and a biosurfactant-producing microorganism was studied in polyethylene glycol and dextran aqueous two-phase systems. In the presence of sodium phosphate, surfactants distributed themselves according to charge. Cationic surfactants preferred the bottom phase, while anionic surfactants were attracted to the top phase. Incresing the phosphate molarity or the pH resulted in a more 1-sided surfactant partitioning. Biosurfactant partitioning was weaker than synthetic surfactant partitioning due to the weaker effective charge and lack to strong specific affinity for any of the phase-forming polymers. Bacillus Subtilis cells partitioned very storngly to the bottom phase. The bioscurfactant, surfactin, produced by this microorganism partitioned to the top phase. Batch fermentations were carried out in an aqueous 2-phase system. Surfactin was produced in larger quanities in the 2-phase fermentation than in the regular mineral salts medium.     

Taking things public: a contribution to address human dimensions of environmental change

This paper addresses the question of environmental change in Amazônia, by looking at the experiences of the large-scale biosphere–atmosphere (LBA) experiment in the Amazon, and three other enterprises—the extractive reserves, the Pilot Programme to Conserve the Brazilian Rain Forest (PPG7) and ecological-economic zoning—that address questions of sustainable development in the region. The LBA experience shows how the integration with the social sciences can be critical for science to explore its own outcomes for society, while the other programmes expose environmental change as a problem with too many intersections within society, so the outcomes of any initiative depends on placing it before a complex, tense and wide arena.     

Specialized use of two fingers in free-ranging aye-ayes (Daubentonia madagascariensis)

The aye-aye (Daubentonia madagascariensis) possesses a highly specialized hand with two fingers, the third and the fourth, being used in a way unparalleled by any other primate. We observed the use of the third and the fourth fingers in various activities in four free-ranging aye-ayes. We found that the thin third finger was used exclusively or preferably for tapping, inserting into the mouth (probably for cleaning the teeth) and probing for nectar, kernels and insects in bamboo, twigs and live wood. In contrast, the robust fourth finger was used preferably when eating jackfruit (Artocarpus heterophyllus). When probing for invertebrates in soft plant tissues and in dead wood, both fingers were used in high proportions. To extract the contents from coconuts, the two fingers were apparently used for different tasks. From this small (686 observations), but unique, study of free-ranging aye-ayes, we conclude that the third finger appears to be specialized for use in tasks requiring high mobility, sensitivity and precision, whereas the fourth finger appears to be specialized for tasks requiring strength, scooping action and deep access.     

Improving the overall environmental performance of existing telecommunications facilities

Superior environmental performance has not traditionally been a goal of managers of telecommunications facilities, but there is now considerable pressure to go ‘beyond compliance,’ even for facilities that have been in existence for many years. In this regard, significant environmental improvement can be achieved by taking a life-cycle perspective. We have conducted a streamlined life-cycle assessment on two existing telecommunications facilities, one providing installation and maintenance services and the other network management services. With the results of this assessment as a basis, we propose a number of generic steps that can be taken to improve the environmental performance of most existing telecommunications facilities.     

A novel biphasic extractive membrane bioreactor for minimization of membrane-attached biofilms

Extractive membrane bioreactor (EMB) systems offer a means of biologically treating wastewaters, but, like other membrane processes, are constrained by their tendency to be fouled by membrane-attached biofilms (MABs). This study describes a new approach to eradicate MAB formation and accumulation in EMB systems. To this end, an innovative EMB configuration, the biphasic extractive membrane bioreactor (BEMB), has been developed. In BEMB systems, the two main constituents of the EMB process, membrane and bacteria, are kept separated and interact via a suitable recirculating solvent. Nineteen candidate solvents were tested to assess their suitability for BEMB application. Based on the results of the solvent selection, guidelines are provided to screen solvents for BEMB application. BEMB and EMB runs were carried out to demonstrate the effectiveness of BEMB technology in avoiding MAB accumulation and to compare BEMB and EMB performance. A synthetic wastewater containing monochlorobenzene (MCB) was used as a model system. Abiotic BEMB and EMB runs were carried out and used as comparative references for estimating the effect of MAB accumulation on system performance. MAB thickness in the BEMB systems was controlled at 18 microm during 1 month of operation, whereas, in the EMB systems, MAB thickness reached 1250 microm. Analysis of mass transport in EMB and BEMB systems revealed that the high affinity of the permeating molecules for the solvent may contribute to a reduction in shell-side mass transfer resistance. This reduction of shell-side mass transfer resistance and the absence of MAB accumulation led to overall mass transfer coefficients of about sevenfold greater (4.5 x 10(-5) m s(-1)) in the BEMB system than in the EMB system (0.6 x 10(-5) m s(-1)).