Improving xylose utilization of defatted rice bran for nisin production by overexpression of a xylose transcriptional regulator in Lactococcus lactis

2017 ◽  
Vol 238 ◽  
pp. 690-697 ◽  
Author(s):  
Jiaheng Liu ◽  
Zelin Ma ◽  
Hongji Zhu ◽  
Qinggele Caiyin ◽  
Dongmei Liang ◽  
...  
BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 6385-6403
Author(s):  
Jiaheng Liu ◽  
Xiangyu He ◽  
Yuhui Du ◽  
Itsanun Wiwatanaratanabutr ◽  
Guangrong Zhao ◽  
...  

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.


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

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 898
Author(s):  
Hebatoallah Hassan ◽  
Daniel St-Gelais ◽  
Ahmed Gomaa ◽  
Ismail Fliss

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.


Author(s):  
Francisco Henrique Pereira Neves Leal ◽  
Caroline de Almeida Senna ◽  
Larine Kupski ◽  
Gabriela da Rocha Lemos Mendes ◽  
Eliana Badiale‐Furlong

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1374
Author(s):  
Bingbing Huang ◽  
Huangwei Shi ◽  
Li Wang ◽  
Lu Wang ◽  
Zhiqian Lyu ◽  
...  

This study was conducted to determine the effects of low-protein diet prepared with different levels of defatted rice bran (DFRB) and weight stages on growth performance and nutrient digestibility of growing–finishing pigs. The animal experiment included three stages. A total of 240 growing pigs with an initial body weight of 28.06 ± 8.56 kg for stage 1 were allocated to five diets including one control group and four DFRB diets supplemented with 2.5%, 5%, 7.5% and 10% DFRB, respectively. The 192 crossbred pigs with initial body weights of 55.03 ± 7.31 kg and 74.55 ± 9.10 kg were selected for stage 2 and stage 3, respectively. Pigs were allocated to four diets including one control group and three DFRB diets supplemented with 10%, 15% and 20% DFRB, respectively. The results showed that with the increase in DFEB intake, the gain: feed was linearly increased (p < 0.05), and the average daily feed intake tended to linearly decrease (p = 0.06) in stage 1. Except for the apparent total tract digestibility (ATTD) of acid detergent fiber (ADF) in stage 3, levels of DFRB had significant effects on the ATTD of gross energy (GE), dry matter (DM), ash, neutral detergent fiber (NDF) and ADF in three weight stages. In stage 1, with the increase in levels of DFRB, the ATTD of NDF and hemicellulose were firstly increased and then decreased (p < 0.01). In stage 2, with the increasing levels of DFRB, the ATTD of DM, ash and cellulose were firstly increased and then decreased (p < 0.01). In stage 3, the ATTD of GE, DM, ash, NDF and hemicellulose decreased linearly with the increase in levels of DFRB (p < 0.01). Collectively, DFRB could be used as a replacement for corns and soybean meal, and weight stage is important to consider when adjusting the additive proportion.


2015 ◽  
Vol 45 (7) ◽  
pp. 1305-1310
Author(s):  
Julio Cezar Dadalt ◽  
Andréa Machado Leal Ribeiro ◽  
Alexandre de Mello Kessler ◽  
William Rui Wesendonck ◽  
Luciane Bockor ◽  
...  

The objective of this study was to evaluate nutritional and energetic value of rice by-products, with or without phytase, using growing pigs. Thirty-six male pigs were housed in individual metabolic cages. Total collection of feces and urine was carried out in two periods of ten days: five days for adaptation and five days for collection. A randomized blocks design was used, considering the sampling period as a block, with five treatments and seven replicates. Two control diets (with and without phytase - Phy) were used in the digestibility calculations, the latter in order to evaluate the enzyme influence on energy digestibility of the tested ingredients. The control diet was replaced by 30% of one of the ingredients: defatted rice bran (DRB) with and without Phy and dephytinised defatted rice bran (DDRB). The use of Phy in the control diet did not influence DRB+Phy energy digestibility. Relative to DRB+Phy, dephytinised defatted rice bran had higher contents of ME and digestible protein but lower digestible P and Ca. Phy supplementation increased Ca and P utilization of DRB and improved energy and protein digestibility. The DRB without Phy showed the lowest digestibility coefficients for all responses. Metabolizable energy, digestible protein, phosphorus and calcium of DRB, DRB+Phy and DDRB were respectively, 2140, 2288 and 2519kcal kg-1; 79.25, 92.41 and 107.10g kg-1; 1.62, 3.41, and 2.11g kg-1 and 2.80, 3.79 and 2.90g kg-1.


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