Francisco Fábio Cavalcante Barros

Surfactina: propriedades químicas, tecnológicas e funcionais para aplicações em alimentos

Surfactin, a lipopeptide produced by strains of Bacillus subtilis, has been proved to be a suitable biosurfactant in several applications. For many years, it has been investigated mainly for oil recovery and environmental usage. Its chemical, technological and functional characteristics turn surfactin into an attractive compound for several utilizations. In this review we emphasize some aspects of surfactin as a new food ingredient and its potential pharmaceutical and health applications.

Production of Enzymes from Agroindustrial Wastes by Biosurfactant-Producing Strains of Bacillus subtilis

Bacteria in the genus Bacillus are the source of several enzymes of current industrial interest. Hydrolases, such as amylases, proteases, and lipases, are the main enzymes consumed worldwide and have applications in a wide range of products and industrial processes. Fermentation processes by Bacillus subtilis using cassava wastewater as a substrate are reported in the technical literature; however, the same combination of microorganisms and this culture medium is limited or nonexistent. In this paper, the amylase, protease, and lipase production of ten Bacillus subtilis strains previously identified as biosurfactant producers in cassava wastewater was evaluated. The LB1a and LB5a strains were selected for analysis using a synthetic medium and cassava wastewater and were identified as good enzyme producers, especially of amylases and proteases. In addition, the enzymatic activity results indicate that cassava wastewater was better than the synthetic medium for the induction of these enzymes.

Response surface analysis for the production of an enantioselective lipase from Aspergillus niger by solid-state fermentation

The lipase produced by the Aspergillus niger strain AC-54 has been widely studied due to its enantioselectivity for racemic mixtures. This study aimed to optimize the production of this enzyme using statistical methodology. Initially a Plackett-Burman (PB) design was used to evaluate the effects of the culture medium components and the culture conditions. Twelve factors were screened: water content, glucose, yeast extract, peptone, olive oil, temperature, NaH2P04, KH2P04, MgS04-7H20, CaCl2, NaCI, and MnS04. The screening showed that the significant factors were water content, glucose, yeast extract, peptone, NaH2P04, and KH2P04, which were optimized using response surface methodology (RSM) and a mathematical model obtained to explain the behavioral process. The best lipase activity was attained using the following conditions: water content (20%), glucose (4.8%), yeast extract (4.0%), and NaH2P04 (4.0%). The predicted lipase activity was 33.03 U/ml and the experimental data confirmed the validity of the model. The enzymatic activity was expressed as µmoles of oleic acid released per minute of reaction (µmol/min).

Propriedades emulsificantes e estabilidade do biossurfactante produzido por Bacillus subtilis em manipueira

Due to the high surface activity, low toxicity, and biodegradability lipopeptides produced by bacteria of the genus Bacillus are among the best biosurfactants known and studied. These compounds are mentioned as potential inputs for various industrial sectors. However, to allow their implementation in industrial processes, it is necessary stability under extreme conditions often associated with of such processes and the maintenance of their properties. The aim of this work was to study the stability of the biosurfactant produced by Bacillus subtilis strain LB5a grown in cassava wastewater in a pilot process. Stability studies were carried out by varying the temperature, pH, and salt (NaCl) concentration. Another study was the evaluation of their emulsifying index in mixtures of water with hydrocarbons and vegetable oils as well as the stability of the emulsions formed. The results showed that the biosurfactant was stable under all combination of temperature and time tested: 100 °C for 140 minutes and 121 °C for up to 60 minutes. It was also stable in concentrations of NaCl from 2.5 to 20%, and pH from 6 to 10. The biosurfactant showed higher values of emulsion index at 24 hours (EI24) to various cyclical and aliphatic hydrocarbons when compared with SDS. The vegetable oils emulsions were stable despite the fact that the profiles of fatty acid chain in the oils were different. All results described characterize these compounds as potential emulsifiers for different industrial applications.

CHAPTER 12:Production of Aroma Compounds by White Biotechnology

Industrially, flavors and fragrances have wide applications in the food, feed, cosmetics, chemical and pharmaceutical sectors and have a global market estimated at billions (109) of dollars. In this respect, the biotechnological production of aroma compounds has emerged as an attractive alternative since it occurs under mild conditions, presents high regio- and enantio-selectivity, does not generate toxic waste, and the products obtained may be labeled as “natural”. Some problems related to these processes impact their final yield, making some of these bioprocesses not feasible for industrial applications to enable commercial application of most published processes. Nevertheless, the progress observed recently in this field has resulted in studies reporting satisfactory yields (on the order of grams per liter), which have potential applications on industrial scale. This chapter is intended to cover the main examples already reported for the production of aroma compounds through biotransformation, the main strategy compatible with industrial scale. Also, strategies from the “Green Chemistry” toolbox with potential applications in (bio)aroma technology will be presented.