Improving nitrogen source utilization from defatted soybean meal for nisin production by enhancing proteolytic function of Lactococcus lactis F44

This work aimed to study the potential of defatted rice bran (DRB) and defatted soybean meal (DSM) as carbon and nitrogen sources for Lactococcus lactis growth and nisin production. First, a maximum nisin yield of 3630 IU/mL was achieved using 40% DRB hydrolysates and 30% DSM hydrolysates, which was 1.13 times greater than that found in commercial media. Second, to simplify the operation and shorten the length of the entire process, the processes of combined hydrolysis of DRB-DSM followed by fermentation, and simultaneous hydrolysis and fermentation of DRB-DSM were developed. Neutral proteinase enhanced the saccharification of DRB by cellulase and α-amylase. Furthermore, the strategy of NADH oxidase expression and hemin addition was innovatively proposed to overcome the oxygen stress in a simultaneous hydrolysis and fermentation process, which could alleviate the lag period following inoculation of L. lactis and result in a 77.3% increase in nisin titer.

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Influence of the phosphorus and nitrogen source on nisin production in Lactococcus lactis subsp. lactis batch fermentations using a complex medium

Applied Microbiology and Biotechnology ◽

10.1007/bf00170422 ◽

1993 ◽

Vol 40 (1) ◽

pp. 17-22 ◽

Cited By ~ 75

Author(s):

Luc De Vuyst ◽

Erick J. Vandamme

Keyword(s):

Nitrogen Source ◽

Lactococcus Lactis ◽

Complex Medium ◽

Nisin Production ◽

Lactococcus Lactis Subsp

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Impact of Nisin and Nisin-Producing Lactococcus lactis ssp. lactis on Clostridium tyrobutyricum and Bacterial Ecosystem of Cheese Matrices

Foods ◽

10.3390/foods10040898 ◽

2021 ◽

Vol 10 (4) ◽

pp. 898

Author(s):

Hebatoallah Hassan ◽

Daniel St-Gelais ◽

Ahmed Gomaa ◽

Ismail Fliss

Keyword(s):

Lactococcus Lactis ◽

Cheddar Cheese ◽

Economic Loss ◽

Gas Production ◽

Clostridium Tyrobutyricum ◽

Nisin Production ◽

Genus Clostridium ◽

Milk Pasteurization ◽

Cheese Slurry ◽

Significant Economic Loss

Clostridium tyrobutyricum spores survive milk pasteurization and cause late blowing of cheeses and significant economic loss. The effectiveness of nisin-producing Lactococcus lactis ssp. lactis 32 as a protective strain for control the C. tyrobutyricum growth in Cheddar cheese slurry was compared to that of encapsulated nisin-A. The encapsulated nisin was more effective, with 1.0 log10 reductions of viable spores after one week at 30 °C and 4 °C. Spores were not detected for three weeks at 4 °C in cheese slurry made with 1.3% salt, or during week 2 with 2% salt. Gas production was observed after one week at 30 °C only in the control slurry made with 1.3% salt. In slurry made with the protective strain, the reduction in C. tyrobutyricum count was 0.6 log10 in the second week at 4 °C with both salt concentration. At 4 °C, nisin production started in week 2 and reached 97 µg/g after four weeks. Metabarcoding analysis targeting the sequencing of 16S rRNA revealed that the genus Lactococcus dominated for four weeks at 4 °C. In cheese slurry made with 2% salt, the relative abundance of the genus Clostridium decreased significantly in the presence of nisin or the protective strain. The results indicated that both strategies are able to control the growth of Clostridium development in Cheddar cheese slurries.

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