ABSTRACT
l-cysteine is an important sulfur-containing α-amino acid. It exhibits multiple physiological functions with diverse applications in pharmaceutical cosmetics and food industry. Here, a strategy of coordinated gene expression between carbon and sulfur modules in Escherichia coli was proposed and conducted for the production of l-cysteine. Initially, the titer of l-cysteine was improved to (0.38±0.02) g/L from zero by enhancing the biosynthesis of l-serine module (serAf, serB and serCCg) and overexpression of CysB. Then, promotion of l-cysteine transporter, increased assimilation of sulfur, reduction or deletion of l-cysteine and l-serine degradation pathway and enhanced expression of cysEf (encoding serine acetyltransferase) and cysBSt (encoding transcriptional dual regulator CysB) were achieved, resulting in an improved l-cysteine titer (3.82±0.01) g/L. Subsequently, expressions of cysM, nrdH, cysK and cysIJ genes that were involved in sulfur module were regulated synergistically with carbon module combined with utilization of sulfate and thiosulfate, resulting in a strain producing (4.17±0.07) g/L l-cysteine in flask shake and (11.94±0.1) g/L l-cysteine in 2 L bioreactor. Our results indicated that efficient biosynthesis of l-cysteine could be achieved by a proportional supply of sulfur and carbon in vivo. This study would facilitate the commercial bioproduction of l-cysteine.
Subject(s)
Escherichia coli/metabolism , Cysteine/metabolism , Bioreactors , Sulfur/metabolism , Serine/metabolismABSTRACT
Ergothioneine is a multifunctional physiological cytoprotector, with broad application in foods, beverage, medicine, cosmetics and so on. Biosynthesis is an increasingly favored method in the production of ergothioneine. This paper summarizes the new progress in the identification of key pathways, the mining of key enzymes, and the development of natural edible mushroom species and high-yield engineering strains for ergothioneine biosynthesis in recent years. Through this review, we aim to reveal the molecular mechanism of ergothioneine biosynthesis and then employ the methods of fermentation engineering, metabolic engineering, and synthetic biology to greatly increase the yield of ergothioneine.
Subject(s)
Antioxidants , Ergothioneine/metabolism , Fermentation , Metabolic EngineeringABSTRACT
Fermentation engineering is an industrial process that uses the transformation of microorganisms or other cells to produce a specific product in a specific bioreactor. Fermentation engineering has developed from an ancient food fermentation relying solely on experience accumulation to an important production mode of food, agriculture, medicine, chemical industry and other means of production and life. It has become a key technology to support the sustainable development of human beings, and is inseparable from the continuous progress of interdisciplinary technology. The interdisciplinary integration and the continuous upward movement of China's global industrial chain will inevitably put forward higher requirements for the cultivation of fermentation engineering composite talents in the new situation. In order to constantly improve the interdisciplinary fermentation engineering compound talent training system, in recent years, the research lab has been refining and improving the concept of talent training, and actively deepening the reform of talent training system. Systematic research and practice have been carried out around the aspects of training program, enrollment system, teacher background, subject setting, scientific research practice, evaluation system, etc., which has promoted the technological progress of fermentation engineering and related supporting industries, and contributed an important force to the transformation of China from a big fermentation country to a powerful fermentation country.
Subject(s)
Humans , Agriculture , China , Fermentation , IndustryABSTRACT
Enzyme engineering combines enzymology and engineering, and is one of the major fields of modern biotechnology. To promote enzyme engineering research in China, we present in this special issue with reviews and original articles focusing on recent relevant advances reported by Chinese scientists.
ABSTRACT
The teaching of the Fermentation Engineering Experiment in normal university must serve for the basic education,placing students' creative spirit and practical ability in the first place.Therefore,teaching reform of the Fermentation Engineering Experiment under the background of new curriculum reform of basic education should be studied from the curriculum content,teaching methodology,training pattern and as-sessment system,in order to cultivate the normal-university students' research ability,working attitude,crea-tive and teaching ability.
ABSTRACT
The traditional fermentation engineering experiment requires a reform on the experimental con-tents and teaching pattern. According to the production process of industrial enzymes, we set up a two-week comprehensive experiment. The students designed and prepared the experiment by themselves. Moreover, the pattern of self-management was used in the process and the experiment scores included the self-assess-ment and objective assessment. It was proved that the new teaching pattern increased the study interesting of students, inspired their initiative and trained their spirits of team cooperation. The teaching effect was im-proved markedly and good ideas are also put forward to solve the possible problem.
ABSTRACT
Some measures were adopted in the fermentation engineering experiment teaching to explore its important role in the quality education.Good effect is achieved in the aspects of cultivating the ability of combining theory with practice,creativeness,thoroughness,and the spirit of hard-working and team coop- eration of the students.
ABSTRACT
This paper mainly discusses the purpose , content , organization of the curriculum design of fermentation engineering and equipment and the teching importance to bioengineering major.