Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation), treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals.

Since 1990, more than 1.8 billion people have gained access to potable water and improved sanitation worldwide. Whilst this represents a vital step towards improving global health and well-being, accelerated population growth coupled with rapid urbanization has further strained existing water supplies. Whilst South Africa aims at spending 0.5% of its GDP on improving sanitation, additional factors such as hydrological variability and growing agricultural needs have further increased dependence on this finite resource. Increasing pressure on existing wastewater treatment plants has led to the discharge of inadequately treated effluent, reinforcing the need to improve and adopt more stringent methods for monitoring discharged effluent and surrounding water sources. This review provides an overview of the relative efficiencies of the different steps involved in wastewater treatment as well as the commonly detected microbial indicators with their associated health implications. In addition, it highlights the need to enforce more stringent measures to ensure compliance of treated effluent quality to the existing guidelines.

Oily wastewater consists of fats, oils and greases together with a broad spectrum of dissolved organic and/or inorganic substances in suspension. It is regarded as one of the most hazardous wastewaters, causing serious environmental and health threats to the ecosystems, flora and fauna. The global increase in the discharge of oily wastewater coupled with stringent regulations for effluent discharge and incessant drive for re-use of treated wastewater necessitate the need for treatment of the wastewater. Conventional approaches employed in the past are inept for oily wastewater treatment due to low treatment efficiency and high operational costs, among others, hence the need for adoption of advanced technologies as promising alternatives to existing treatment systems for oily wastewater. Furthermore, the use of combined treatment processes is effective for the removal of hazardous pollutants present in high-strength oily wastewater. This review provides insights into advanced and emerging state-of-the-art technologies for safe and efficient treatment of industrial oily wastewater.

Many classes of compounds have been shown to play an important role in the development of flavour characteristics of beer. This significantly influences its taste and sensory properties, thus affecting its market performance. Despite the intensive research aimed at unravelling the precise mechanism and regulation of flavour formation in beer, current knowledge remains far from complete. Several reviews are available on the general composition of beer and yeast metabolic pathways involved in the production of volatile compounds in beer. However, a limited amount of work has been reported concerning the influence of some of the beer constituents and other important parameters on beer flavour. This paper reviews the current knowledge of the biochemistry behind flavour formation in beer and discusses the different factors that influence its formation and how it can be controlled during brewery fermentation. Copyright © 2017 The Institute of Brewing & Distilling

Perspectives on the probiotic potential of lactic acid bacteria from African traditional fermented foods and beverages