The role of marine anaerobic bacteria and archaea in bioenergy production

The development of products from marine bioresources is gaining importance in the biotechnology sector. The global market for Marine Biotechnology products and processes was, in 2010, estimated at 2.8 billion with a cumulative annual growth rate of 510% (Børresen et al., Marine biotechnology: a new vision and strategy for Europe. Marine Board Position Paper 15. Beernem: Marine Board-ESF, 2010). Marine Biotechnology has the potential to make significant contributions towards the sustainable supply of food and energy, the solution of climate change and environmental degradation issues, and the human health. Besides the creation of jobs and wealth, it will contribute to the development of a greener economy. Thus, huge expectations anticipate the global development of marine biotechnology. The marine environment represents more than 70% of the Earths surface and includes the largest ranges of temperature, light and pressure encountered by life. These diverse marine environments still remain largely unexplored, in comparison with terrestrial habitats. Notwithstanding, efforts are being done by the scientific community to widespread the knowledge on oceans microbial life. For example, the J. Craig Venter Institute, in collaboration with the University of California, San Diego (UCSD), and Scripps Institution of Oceanography have built a state-of-the-art computational resource along with software tools to catalogue and interpret microbial life in the worlds oceans. The potential application of the marine biotechnology in the bioenergy sector is wide and, certainly, will evolve far beyond the current interest in marine algae. This chapter revises the current knowledge on marine anaerobic bacteria and archaea with a role in bio-hydrogen production, syngas fermentation and bio-electrochemical processes, three examples of bioenergy production routes.

By-products of beer fermentation

Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters; as well as the successful reduction of undesirable by-products such as diacetyl. While higher alcohols and esters contribute rather positively to the beer aroma, diacetyl is mostly unwelcome for beer types with lighter taste. Thus, the complex metabolic pathways in yeast responsible for the synthesis of both pleasant and unpleasant by-products of fermentation were given special attention in this last chapter.

The brewing yeast

The concept of brewing science is very recent when compared with the history of beer. It began with the microscopic observations of Louis Pasteur and evolved through the last century with improvements in engineering, microbiology, and instrumental analysis. However, the most profound insight into brewing processes only emerged in the past decades through the advances in molecular biology and genetic engineering. These techniques allowed scientists to not only affirm their experiences and past findings, but also to clarify a vast number of links between cellular structures and their role within the metabolic pathways in yeast. This chapter is therefore dedicated to the behavior of the brewing yeast during fermentation. The discussion puts together the recent findings in the core carbon and nitrogen metabolism of the model yeast Saccharomyces cerevisiae and their fermentation performance.

An overview of the brewing process

The first chapter of this book has an introductory character, which discusses the basics of brewing. This includes not only the essential ingredients of beer, but also the steps in the process that transforms the raw materials (grains, hops) into fermented and maturated beer. Special attention is given to the processes involving an organized action of enzymes, which convert the polymeric macromolecules present in malt (such as proteins and polysaccharides) into simple sugars and amino acids; making them available/assimilable for the yeast during fermentation.

The state of art of biological processes in paternal care

This review of the state of art aimed to present the most recent data on neuronal, neurochemical, hormonal and genetic bases of paternal care using MEDLINE and PsycInfo databases (1970-2013). An integrated model of biological substrates that assist men in the transition to fatherhood is presented. Guided by a genetic background, hypothalamic-midbrain-limbic-paralimbic-cortical circuits were found to be activated in fathers when infant stimuli are presented. A set of specifi c neuropeptides and steroid hormones are produced and seem to be related to brain activation, potentiating the paternal phenotype. Together, genetic, brain and hormonal processes suggest the existence of biological bases of paternal care in humans, activated and enhanced by infant stimuli and responsive to variations in the father-infant relationship.

Production of biohydrogen from dark fermentation of organic wastes

Dissertação de mestrado em Bioengenharia

Biotechnological production and application of fructooligosaccharides

Currently, prebiotics are all carbohydrates of relatively short chain length. An important group is the fructooligosaccharides, which are a special kind of prebiotics associated to their selective stimulation of the activity of certain groups of colonic bacteria that have a positive and beneficial effect on intestinal microbiota, reducing incidence of gastrointestinal infections, respiratory and also possessing a recognized bifidogenic effect. Traditionally, these prebiotic compounds have been obtained through extraction processes from some plants, as well as through enzymatic hydrolysis of sucrose. However, different fermentative methods have also been proposed for the production of fructooligosaccharides, such as solid-state fermentation utilizing various agroindustrial by-products. By optimizing the culture parameters, fructooligosaccharides yields and productivity can be improved. The use of immobilized enzymes and cells has also been proposed as being an effective and economic method for large-scale production of fructooligosaccharides. This paper is an overview on the results of recent studies on fructooligosacharides biosynthesis, physicochemical properties, sources, biotechnological production and applications.

Malolactic fermentation in winemaking: evaluation of operational parameters

Dissertação de mestrado em Bioengenharia