scholarly journals Engineering of Bacillus subtilis 168 for Increased Nisin Resistance

2009 ◽  
Vol 75 (21) ◽  
pp. 6688-6695 ◽  
Author(s):  
Mette E. Hansen ◽  
Romilda Wangari ◽  
Egon B. Hansen ◽  
Ivan Mijakovic ◽  
Peter R. Jensen
Keyword(s):  
Bacillus Subtilis ◽  
Lactococcus Lactis ◽  
Resistance Genes ◽  
Food Industry ◽  
Cost Effective ◽  
Heterologous Production ◽  
Host Organism ◽  
Synthetic Promoter ◽  
Bacillus Subtilis 168 ◽  
Promoter Library

ABSTRACT Nisin is a natural bacteriocin produced commercially by Lactococcus lactis and widely used in the food industry as a preservative because of its broad host spectrum. Despite the low productivity and troublesome fermentation of L. lactis, no alternative cost-effective host has yet been found. Bacillus subtilis had been suggested as a potential host for the biosynthesis of nisin but was discarded due to its sensitivity to the lethal action of nisin. In this study, we have reevaluated the potential of B. subtilis as a host organism for the heterologous production of nisin. We applied transcriptome and proteome analyses of B. subtilis and identified eight genes upregulated in the presence of nisin. We demonstrated that the overexpression of some of these genes boosts the natural defenses of B. subtilis, which allows it to sustain higher levels of nisin in the medium. We also attempted to overcome the nisin sensitivity of B. subtilis by introducing the nisin resistance genes nisFEG and nisI from L. lactis under the control of a synthetic promoter library.

A Foodgrade Preparation of Nisin from Diluted Milk Fermented with Lactococcus lactis W8

2009 ◽  
Vol 72 (12) ◽  
pp. 2615-2617 ◽  
Author(s):  
SURANJITA MITRA ◽  
BIDHAN CHANDRA MUKHOPADHYAY ◽  
SWADESH RANJAN BISWAS
Keyword(s):  
Antimicrobial Activity ◽  
Lactococcus Lactis ◽  
Food Industry ◽  
Skim Milk ◽  
Cost Effective ◽  
Fermented Milk ◽  
Maximum Production ◽  
Nisin Z ◽  
Liquid Part ◽  
Lactis Strain

Lactococcus lactis strain W8, which contains the nisin Z gene in its genome, grew well and produced nisin in cow's milk at temperatures of 30 to 37°C. Maximum production of nisin was achieved at 6 h and was 4,000 activity units (AU) per ml in skim milk and 2,400 AU/ml in 3% fat milk. The organism produced nisin even in 20 times diluted skim milk and 3% fat milk at 1,000 and 600 AU/ml, respectively. Boiling of the fermented milk (pH 4.2) made with this culture allowed the separation of the liquid part (whey) from the curd. When 20 times diluted skim milk was fermented and the whey derived from it was lyophilized, the yield of nisin was 60,000 AU/g. The antimicrobial activity of the nisin preparation was stable for at least 1 year at refrigeration temperature. L. lactis W8 may have significant applications in the food industry for a cost-effective natural nisin preparation.

scholarly journals Electrochemical Biosensors in Food Safety: Challenges and Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2940
Author(s):  
Antonella Curulli
Keyword(s):  
Food Industry ◽  
Electrochemical Sensors ◽  
Cost Effective ◽  
Electrochemical Biosensors ◽  
Food Chains ◽  
Sensing Systems ◽  
Highly Sensitive ◽  
Skilled Personnel ◽  
Recent Developments ◽  
Key Issues

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expensive and complex procedures, and skilled personnel. Therefore, developing performant electrochemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.

Crystal Structure of Urate Oxidase from Bacillus Subtilis 168

2019 ◽  
Vol 64 (7) ◽  
pp. 1126-1133 ◽  
Author(s):  
A. Nayab ◽  
S. A. Moududee ◽  
Y. Shi ◽  
Y. Jiang ◽  
Q. Gong
Keyword(s):  
Crystal Structure ◽  
Bacillus Subtilis ◽  
Urate Oxidase ◽  
Bacillus Subtilis 168
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