scholarly journals Exploring the Optimization of UV Mutants of Streptomyces clavuligerus for Clavulanic Acid Production

2019 ◽  
pp. 1-8
Author(s):  
Isara Lourdes Cruz-Hernández ◽  
Eliton Da Silva Vasconcelos ◽  
Juliana Conceição Teodoro ◽  
Alvaro De Baptista-Neto ◽  
Maria Lucia Gonsales Da Costa Araujo ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Bacterial Resistance ◽  
Soybean Protein ◽  
Wild Strain ◽  
Strain Improvement ◽  
Streptomyces Clavuligerus ◽  
Protein Isolate ◽  
Submerged Cultures ◽  
Soybean Protein Isolate ◽  
Industrial Strains

Streptomyces clavuligerus, initially described as a Cephamycin C producer, has been currently utilized to produce clavulanic acid (CA) which shows low antibiotic activity, being, however, a strong β-lactamase inhibitor, enzymes responsible for bacterial resistance to β–lactam antibiotics. Genetic improvement by physical and chemical agents is mandatory since, due to its genetic instability, industrial strains lose production capability making necessary a steady and frequent strain improvement and a screening procedure. The objective of this work was to obtain an increase in CA production in submerged cultures by utilizing mutants obtained by UV radiation of the wild strain Streptomyces clavuligerus ATCC 27064. Submerged cultures were performed, with the best mutants selected, in a 5L bench-scale bioreactor, batch-wise, utilizing a complex medium containing glycerol and a soybean protein isolate as the main components. The mutant 70 was able to produce a maximum CA concentration of 500 mg.L-1, approximately 1.6 times higher than the wild strain. Another finding was a higher CA productivity of 29.5 mg.h-1.L-1 with this mutant, although a lower specific growth rate had been observed.

scholarly journals Enhanced production of Clavulanic acid by improving glycerol utilization using reporter-guided mutagenesis of an industrial Streptomyces clavuligerus strain

2021 ◽  
Author(s):  
Chang-Hun Shin ◽  
Hang Soo Cho ◽  
Hyung-Jin Won ◽  
Ho Jeong Kwon ◽  
Chan-Wha Kim ◽  
...  
Keyword(s):  
Clavulanic Acid ◽  
Wild Type Strain ◽  
Random Mutagenesis ◽  
Streptomyces Clavuligerus ◽  
Wild Type ◽  
Mutant Selection ◽  
Enhanced Production ◽  
Industrial Strains ◽  
Glycerol Utilization

Abstract Clavulanic acid (CA) produced by Streptomyces clavuligerus is a clinically important β-lactamase inhibitor. It is known that glycerol utilization can significantly improve cell growth and CA production of S. clavuligerus. We found that the industrial CA-producing S. clavuligerus strain OR generated by random mutagenesis consumes less glycerol than the wild-type strain; we then developed a mutant strain in which the glycerol utilization operon is overexpressed, as compared to the parent OR strain, through iterative random mutagenesis and reporter-guided selection. The CA production of the resulting S. clavuligerus ORUN strain was increased by approximately 31.3 per cent (5.21 ± 0.26 g/L) in a flask culture and 17.4 per cent (6.11 ± 0.36 g/L) in a fermenter culture, as compared to that of the starting OR strain. These results confirmed the important role of glycerol utilization in CA production and demonstrated that reporter-guided mutant selection is an efficient method for further improvement of randomly mutagenized industrial strains.

scholarly journals Optimization of High Hydrostatic Pressure Treatments on Soybean Protein Isolate to Improve Its Functionality and Evaluation of Its Application in Yogurt

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 667
Author(s):  
Chenxiao Wang ◽  
Hao Yin ◽  
Yanyun Zhao ◽  
Yan Zheng ◽  
Xuebing Xu ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Activity Index ◽  
Soybean Protein ◽  
Protein Isolate ◽  
Water Holding Capacity ◽  
Holding Time ◽  
Emulsifying Activity ◽  
Soybean Protein Isolate ◽  
Water Holding

This work aimed to improve the functional properties of soybean protein isolate (SPI) by high hydrostatic pressure (HHP) and develop SPI incorporated yogurt. Response surface methodology (RSM) was used to optimize the HHP treatment parameters, including pressure, holding time, and the ratio of SPI/water. Water holding capacity, emulsifying activity index, solubility, and hardness of SPI gels were evaluated as response variables. The optimized HPP treatment conditions were 281 MPa of pressure, 18.92 min of holding time, and 1:8.33 of SPI/water ratio. Water and oil holding capacity, emulsifying activity, and stability of SPI at different pH were improved. Additionally, relative lipoxygenase (LOX) activity of HHP treated SPI (HHP-SPI) was decreased 67.55 ± 5.73%, but sulphydryl group content of HHP-SPI was increased 12.77%, respectively. When incorporating 8% of SPI and HHP-SPI into yogurt, the water holding capacity and rheological properties of yogurt were improved in comparison with yogurt made of milk powders. Moreover, HHP-SPI incorporated yogurt appeared better color and flavor.

Thermal Stability of Soybean Protein Isolate-Based Oleic Acid/Stearic Acid Blend Edible Films

2013 ◽  
Vol 469 ◽  
pp. 171-174 ◽  
Author(s):  
Ning Zhang ◽  
Si Yao Sui ◽  
Zhe Wang ◽  
Zhong Su Ma
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Stearic Acid ◽  
Soybean Protein ◽  
Soy Protein Isolate ◽  
Edible Films ◽  
Protein Isolate ◽  
Soybean Protein Isolate ◽  
The Matrix ◽  
Thermal Stability Of

Edible films were prepared using soy protein isolate (4g/100g), oleic acid (0-2g/100g) and stearic acid (0-2g/100g). Effects of the type and ratio of fatty acids (oleic acid and stearic acid) on the thermal properties of soybean protein isolate-based films were investigated. The results indicated that the addition of oleic acid and stearic acid take a significant effect on the thermal stability of soybean protein isolate-based films, as may attribute to that oleic acid is an amphiphilic substance that interacts with both polar and hydrophobic sites on proteins, thus it could improve the functional properties of the films. Besides, the solid state and hydrophobic nature of stearic acid could help limit water diffusion in the matrix more efficiently when it is well-integrated in the matrix through the surfactant action of oleic acid.

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