No abstract

Production of bacterial nanocellulose (BNC) is becoming increasingly popular owing to its environmentally friendly properties. Based on this benefit of BNC production, researchers have also begun to examine the capacity for cellulose production through microbial hosts. Indeed, several research groups have developed processes for BNC production, and many studies have been published to date, with the goal of developing methods for large-scale production. During BNC bioproduction, the culture medium represents approximately 30 % of the total cost. Therefore, one important and challenging aspect of the fermentation process is identification of a new cost-effective culture medium that can facilitate the production of high yields within short periods of time, thereby improving BNC production and permitting application of BNC in the biotechnological, medical, pharmaceutical, and food industries. In this review, we addressed different aspects of BNC production, including types of fermentation processes and culture media, with the aim of demonstrating the importance of these parameters.

Worldwide, bacterial resistance to chemical antibiotics has reached such a high level that endangers public health. Presently, the adoption of alternative strategies that promote the elimination of resistant microbial strains from the environment is of utmost importance. This review discusses and analyses several (potential) alternative strategies to current chemical antibiotics. Bacteriophage (or phage) therapy, although not new, makes use of strictly lytic phage particles as an alternative, or a complement, in the antimicrobial treatment of bacterial infections. It is being rediscovered as a safe method, because these biological entities devoid of any metabolic machinery do not possess any affinity whatsoever to eukaryotic cells. Lysin therapy is also recognized as an innovative antimicrobial therapeutic option, since the topical administration of preparations containing purified recombinant lysins with amounts in the order of nanograms, in infections caused by Gram-positive bacteria, demonstrated a high therapeutic potential by causing immediate lysis of the target bacterial cells. Additionally, this therapy exhibits the potential to act synergistically when combined with certain chemical antibiotics already available on the market. Another potential alternative antimicrobial therapy is based on the use of antimicrobial peptides (AMPs), amphiphilic polypeptides that cause disruption of the bacterial membrane and can be used in the treatment of bacterial, fungal and viral infections, in the prevention of biofilm formation, and as antitumoral agents. Interestingly, bacteriocins are a common strategy of bacterial defense against other bacterial agents, eliminating the potential opponents of the former and increasing the number of available nutrients in the environment for their own growth. They can be applied in the food industry as biopreservatives and as probiotics, and also in fighting multi-resistant bacterial strains. The use of antibacterial antibodies promises to be extremely safe and effective. Additionally, vaccination emerges as one of the most promising preventive strategies. All these will be tackled in detail in this review paper.

Two-phase systems can be exploited in separation science for the extraction/purification of desired biomolecules. This article reviews recent experimental work on the use of aqueous two-phase polymer systems, two-phase aqueous micellar systems and reversed micellar systems for the extraction/purification of biomolecules. The experimental partitioning behavior of different biomolecules is reviewed and new results with nisin and lipopolysaccharides are presented. An extensive description of each system is presented, based on the biomolecules behavior and the tools employed to improve their extraction and purification.

The use of biopharmaceuticals dates from the 19th century and within 5–10 years, up to 50% of all drugs in development will be biopharmaceuticals. In the 1980s, the biopharmaceutical industry experienced a significant growth in the production and approval of recombinant proteins such as interferons (IFN α, β, and γ) and growth hormones. The production of biopharmaceuticals, known as bioprocess, involves a wide range of techniques. In this review, we discuss the technology involved in the bioprocess and describe the available strategies and main advances in microbial fermentation and purification process to obtain biopharmaceuticals.

Bacterial cellulose (BC) is used in different fields as a biological material due to its unique properties. Despite there being many BC applications, there still remain many problems associated with bioprocess technology, such as increasing productivity and decreasing production cost. New technologies that use waste from the food industry as raw materials for culture media promote economic advantages because they reduce environmental pollution and stimulate new research for science sustainability. For this reason, BC production requires optimized conditions to increase its application. The main objective of this study was to evaluate BC production by Gluconacetobacter xylinus using industry waste, namely, rotten fruits and milk whey, as culture media. Furthermore, the structure of BC produced at different conditions was also determined. The culture media employed in this study were composed of rotten fruit collected from the disposal of free markets, milk whey from a local industrial disposal, and their combination, and Hestrin and Schramm media was used as standard culture media. Although all culture media studied produced BC, the highest BC yield-60 mg/mL-was achieved with the rotten fruit culture. Thus, the results showed that rotten fruit can be used for BC production. This culture media can be considered as a profitable alternative to generate high-value products. In addition, it combines environmental concern with sustainable processes that can promote also the reduction of production cost.

Due to the growing number of outbreaks of infection in hospital and nurseries, it becomes essential to set up a sanitation program that indicates that the appropriate chemical agent was chosen for application in the most effective way. Validating the effectiveness of decontamination and disinfection is an important and often challenging task. In order to study and compare the behavior of selected microorganisms, they were submitted to minimal inhibitory concentration (MIC). The MIC intervals, which reduced bacteria populations over 6 log10, were: 59 to 156 mg/L of quaternary ammonium compounds (QACs); 63 to 10000 mg/L of chlorhexidine; 1375 to 3250 mg/L of glutaraldehyde; 39 to 246 mg/L of formaldehyde; 43750 to 87500 mg/L of ethanol; 1250 to 6250 mg/L of iodine in polyvinyl-pyrolidone complexes, 150 to 4491 mg/L of chlorine-releasing-agents (CRAs) and 469 to 2500 mg/L of hydrogen peroxide. Chlorhexidine showed non inhibitory activity over germinating spores. A. calcoaceticus showed resistance to the majority of the agents tested, followed by E. cloacae and S. marcescens. Uniterms: Minimal inhibitory concentration. Disinfectant agents. Sterilizing agents. Sanitation/ programs.Devido ao número crescente de surtos de infecção hospitalar, torna-se proeminente o estabelecimento de um programa de sanitização que liste os agentes químicos a serem empregados e o modo de aplicação mais efetivo. Validação da eficácia de descontaminação é uma tarefa ao mesmo tempo importante e desafiadora. Para estudar e comparar o comportamento dos microrganismos selecionados foram realizados ensaios de concentração inibitória mínima (CIM). A CIM capaz de reduzir o bioburden inicial (>6 log10) foi: 59 -156 mg/L de quartenários de amônia; 63 -10000 mg/L de clorexidina, 1375 -3250 mg/mL de glutaraldeído, 39 -246 mg/L de formaldeído, 43750 -87500 mg/L de etanol 1250 -6250 mg/L de PVPI, 150 -4491 mg/L de compostos liberadores de cloro e 469 -2500 mg/L de peróxido de hidrogênio.

Bromelain is a cysteine protease found in pineapple tissue. Because of its anti-inflammatory and anti-cancer activities, as well as its ability to induce apoptotic cell death, bromelain has proved useful in several therapeutic areas. The market for this protease is growing, and several studies exploring various properties of this molecule have been reported. This review aims to compile this data, and summarize the main findings on bromelain in the literature to date. The physicochemical properties and stability of bromelain under different conditions are discussed. Several studies on the purification of bromelain from crude extracts using a wide range of techniques such as liquid-liquid extractions by aqueous two-phase system, ultrafiltration, precipitation, and chromatography, have been reported. Finally, the various applications of bromelain are presented. This review therefore covers the main properties of bromelain, aiming to provide an up-to-date compilation of the data reported on this enzyme.