Bacteriocin production by Bifidobacterium spp. A review

Bacteriocins are ribosomally-synthesized antibacterial peptides. These compounds are produced by a broad variety of different bacteria belonging mainly to the genus Bifidobacterium, to which health promoting properties have frequently been attributed. However, despite the fact that the identification of Bifidobacterium-associated bacteriocins was first reported in 1980 and that they exhibit antimicrobial activity against pathogenic microorganisms such as Listeria monocytogenes, Clostridium perfringens, Escherichia coli, relatively little information is still available about the antimicrobial compounds produced by strains of this genus. More detailed understanding of the action mechanisms of these antimicrobials could allow us to determine the extent to which their production contributes to the probiotic properties of specific bifidobacteria strains and, potentially, be of crucial significance for ultimate preservation of functional foods or pharmaceutical applications. Here we review what is already known about their structure, classification, mode of action, functionality, immunity, production and purification

Novel biotechnological applications of bacteriocins: A review

Bacteriocins are antimicrobial peptides produced by a large number of bacteria, including lactic acid bacteria (LAB), which are normally effective against other Gram positive bacteria. Most bacteriocins exhibit activity against significant spoilage and disease-causing Gram positive pathogenic bacteria. For this reason,, and they may be applied in, for example,are used in a lot of different applications, among them biopreservation, shelf-life extension, clinical antimicrobials and control of the fermentation micro flora. The demand for these productscompounds, such as food without adding chemical preservatives and refrigerated food has brought great interest in for new technologies that enhance the microbiological safety of these food products such as foods without adding chemical preservatives and refrigerated foods. Also the dramatic rise in antibiotic-resistant pathogens has stimulated renewed efforts to identify, develop or redesign antibiotics active against these multi-resistant bacteria. In this review we focus on the recent classification of bacteriocins, their mode of action, biotechnological applications in food and pharmaceutical industryindustries, the problems such as purification techniques and biosafety, as well as and also the recent attempts to generate custom custom-designed bacteriocins using genetic engineering techniques

Lactic acid properties, applications and production: A review

Lactic acid was discovered in 1780 by C.W. Scheele in sour milk, and in 1881 Fermi obtained lactic acid by fermentation, resulting in its industrial production. The yearly world lactic acid production is expected to reach 259 thousand metric tons by the year 2012. The interest in lactic acid is related to many aspects, among which is its relatively high added-value. In addition, such a chemical is GRAS (Generally Recognized As Safe), being recognized as harmless by the United States Food and Drug Administration, has a market with great growth potential, can be alternatively produced by fermentation or chemical synthesis and can employ a large variety of different waste materials as substrates. Lactic acid has many applications. Its existence in the form of two stereoisomers does in fact make the application of one of them or of the racemic mixture of great concern in different fields. In particular, the food and pharmaceutical industries have a preference for the isomer L(+), the only one that can be metabolized by the human body; however, the chemical industry requires one of the pure isomers or a mixture of both, according to the application. This review describes biotechnological processes to obtain lactic acid from polymeric substrates such as starchy and lignocellulosic materials. Open challenges are related to the technological optimization of the fermentation process and product purification and recovery. In addition, the opportunities and difficulties associated with using raw materials for lactic acid production are discussed