Descrição
Nisin is a commercially available bacteriocin of the lantibiotic group produced by Lactococcus lactis ATCC 11454.
The importance of nisin as an effective preservative is the fact that its spectrum of inhibitory activity includes
almost all Gram-positive, Gram-negative and spoilage bacteria. With several favorable characteristics, this
compound has been widely used as a natural food biopreservative. On the other hand, biotechnological production
of fuel ethanol from different raw materials (sucrose-containing feedstocks - mainly sugar cane, starchy materials
and lignocellulosic biomass) has led to the increase in the researches with trends for improving the bio-ethanol
production. During these processes of bio-ethanol production antibiotic agents are added to the pre-fermented
broth to prevent unwanted microbial growth. Thus, different questions have been made in relation to performance
of the application of the nisin as a natural antibiotic to the ethanol production, as well as their beneficial effects
about the yield and productivity in this process. However, the solution to this problematic depends firstly on how
the development and implementation of technologies based on nisin production will be undertaken. Perspectives
towards the development of modern procedures of nisin production are still needed. In this work the main proposal
that has been discussed is the applicability of a novel micro-reactor operated under oscillatory flow mixing
envisaged for parallel screening and/or development of industrial bioprocesses in the nisin production. For this
reason, initially the objective of this study was to investigate the milk whey, a byproduct from dairy industries, in
nisin production aiming to evaluate the growth conditions for L. lactis. In batch cultures, L. lactis was performed in
raw milk whey and the nisin activity was assayed through agar diffusion utilizing Lactobacillus sakei ATCC 15521.
The results showed that milk whey media is propitious to develop L. lactis cells and produce nisin, reaching activity
around 105 AU.mL-1. Biological processing of milk sub-products (milk whey) can be considered one of profitable
utilization alternatives, generating high-value bioproducts and contributing to decrease rivers disposal. The use of
these sub-products as substrate together with further studies related to application of batch or continuous
oscillatory flow reactor would take the more efficient nisin production and finally to a possibility of its evaluation
and use in bio-ethanol production.
; Silva, D. P. 
