scholarly journals Simultaneous hydrolysis and fermentation of defatted rice bran and defatted soybean meal for nisin production with engineered Lactococcus lactis

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6385-6403
Author(s):  
Jiaheng Liu ◽  
Xiangyu He ◽  
Yuhui Du ◽  
Itsanun Wiwatanaratanabutr ◽  
Guangrong Zhao ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Rice Bran ◽  
Soybean Meal ◽  
Nadh Oxidase ◽  
Nitrogen Sources ◽  
Nisin Production ◽  
Carbon And Nitrogen ◽  
Defatted Soybean Meal ◽  
Commercial Media ◽  
Defatted Rice Bran

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.

scholarly journals Production of Extracellular Laccase fromBacillus subtilisMTCC 2414 Using Agroresidues as a Potential Substrate

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Narayanan P. Muthukumarasamy ◽  
Beenie Jackson ◽  
Antony Joseph Raj ◽  
Murugan Sevanan
Keyword(s):  
Rice Bran ◽  
Wheat Bran ◽  
Metal Ion ◽  
Nitrogen Sources ◽  
Precipitation Method ◽  
Food Industries ◽  
Carbon And Nitrogen ◽  
Molecular Weights ◽  
Extracellular Laccase ◽  
Potential Substrate

Laccases are the model enzymes for multicopper oxidases and participate in several applications such as bioremediation, biopulping, textile, and food industries. Laccase producing bacterium,Bacillus subtilisMTCC 2414, was subjected to optimization by conventional techniques and was partially purified using ammonium salt precipitation method. The agroresidue substrates used for higher yield of laccase were rice bran and wheat bran. Maximum production was achieved at temperature 30°C (270 ± 2.78 U/mL), pH 7.0 (345 ± 3.14 U/mL), and 96 h (267 ± 2.64 U/mL) of incubation. The carbon and nitrogen sources resulted in high enzyme yield at 3% sucrose (275 ± 3.11 U/mL) and 3% peptone (352.2 ± 4.32 U/mL) for rice bran and 3% sucrose (247.4 ± 3.51 U/mL) and 3% peptone (328 ± 3.33 U/mL) for wheat bran, respectively. The molecular weights of partially purified laccase were 52 kDa for rice bran and 55 kDa for wheat bran. The laccase exhibited optimal activity at 70°C (260.3 ± 6.15 U/mL), pH 9.0 (266 ± 4.02 U/mL), and metal ion CuSO4(141.4 ± 6.64) was found to increase the production. This is the first report that delivers the higher yield of laccase produced fromB. subtilisMTCC 2414 using agroresidues as a potential substrate.

scholarly journals Biocatalyst: Cellulase Production in Solid State Fermentation (SSF) Using Rice Bran as Substrate

2020 ◽  
Vol 11 (1) ◽  
pp. 7689-7699
Keyword(s):  
Rice Bran ◽  
Nitrogen Sources ◽  
Cellulase Production ◽  
Culture Conditions ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen ◽  
Glucose Carbon ◽  
Biological Transformation ◽  
Fermentation Period ◽  
Filter Paper Assay

The study was aimed to analyze the biological transformation of cellulose in rice bran by Aspergillus flavus SB04 in SSF for 28 days. The culture conditions such as pH, temperature, moisture content were optimized for the effective production of the enzyme in SSF. Effect of carbon and nitrogen sources on cellulase production was further estimated in SMF and were quantified for 24hrs intervals for 7 days Maximum cellulase production for rice bran was observed to be high in glucose (carbon source) and yeast extract (nitrogen source) at initial moisture 75ml, pH 6, temperature 33°C and fermentation period was 14th day that was optimized using response surface methodology. The enzyme production was analyzed individually by dinitrosalicylic acid (DNS) method, Lowry protein estimation, and filter paper assay. The lignocellulosic degradation was observed and confirmed by FTIR and SEM. The degradation of cellulose periodically increases after 7 days, which influences the yield of cellulase enzyme.

QUALITY ASPECTS OF PAN BREAD PREPARED BY PARTIAL SUBSTITUTION OF WHEAT FLOUR WITH DEFATTED RICE BRAN

2019 ◽  
Vol 4 (3) ◽  
pp. 89-99
Author(s):  
A.S. Sallam ◽  
A.H. Khalil ◽  
M.M. Mostafa ◽  
A.A. El Bedawy ◽  
Aml A. Atef
Keyword(s):  
Wheat Flour ◽  
Rice Bran ◽  
Partial Substitution ◽  
Defatted Rice Bran ◽  
Pan Bread ◽  
Quality Aspects

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

Foods ◽  
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.

scholarly journals A highly thermotolerant laccase produced by Cerrena unicolor strain CGMCC 5.1011 for complete and stable malachite green decolorization

AMB Express ◽  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yanhua Yao ◽  
Guimei Zhou ◽  
Yonghui Lin ◽  
Xinqi Xu ◽  
Jie Yang
Keyword(s):  
Malachite Green ◽  
Fermentation Broth ◽  
Nitrogen Sources ◽  
Life Time ◽  
Industrial Applications ◽  
Dynamics Simulation ◽  
Carbon And Nitrogen ◽  
Cdna Sequences ◽  
Cerrena Unicolor ◽  
Future Work

Abstract Laccases are a class of multi-copper oxidases with important industrial values. A thermotolerant laccase produced by a basidiomycete fungal strain Cerrena unicolor CGMCC 5.1011 was studied. With glycerin and peptone as the carbon and nitrogen sources, respectively, a maximal laccase activity of 121.7 U/mL was attained after cultivation in the shaking flask for 15 days. Transcriptomics analysis revealed an expressed laccase gene family of 12 members in C. unicolor strain CGMCC 5.1011, and the gene and cDNA sequences were cloned. A glycosylated laccase was purified from the fermentation broth of Cerrena unicolor CGMCC 5.1011 and corresponded to Lac2 based on MALDI-TOF MS/MS identification. Lac2 was stable at pH 5.0 and above, and was resistant to organic solvents. Lac2 displayed remarkable thermostability, with half-life time of 1.67 h at 70 ºC. Consistently, Lac2 was able to completely decolorize malachite green (MG) at high temperatures, whereas Lac7 from Cerrena sp. HYB07 resulted in accumulation of colored MG transformation intermediates. Molecular dynamics simulation of Lac2 was conducted, and possible mechanisms underlying Lac2 thermostability were discussed. The robustness of C. unicolor CGMCC 5.1011 laccase would not only be useful for industrial applications, but also provide a template for future work to develop thermostable laccases.

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