Wang Juan, Zhang Jing, Wang Lu, Liu Hong, Li Ning, Zhou Huanxia, Ning Zhanguo, Zhang Weican, Wang Lushan, Huang Feng, Zhong Yaohua
State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China.
Shandong Xingguang Sugar Group Co. Ltd, Laoling, Dezhou, 253600, People's Republic of China.
Biotechnol Lett. 2021 Jun;43(6):1175-1182. doi: 10.1007/s10529-021-03099-w. Epub 2021 Feb 11.
To achieve continuous production of fructooligosaccharides (FOS) by recycling of the mycelial cells containing the thermal-stable β-fructofuranosidase in Aspergillus niger without immobilization.
The thermal-stable β-fructofuranosidase FopA-V1 was successfully expressed in A. niger ATCC 20611 under the control of the constitutive promoter PgpdA. The engineered A. niger strain FV1-11 produced the β-fructofuranosidase with improved thermostability, which remained 91.2% of initial activity at 50 °C for 30 h. Then its mycelial β-fructofuranosidase was recycled for the synthesis of FOS. It was found that the enzyme still had 79.3% of initial activity after being reused for six consecutive cycles, whereas only 62.3% β-fructofuranosidase activity was detected in the parental strain ATCC 20611. Meanwhile, the FOS yield of FV1-11 after six consecutive cycles reached 57.1% (w/w), but only 51.0% FOS yield was detected in ATCC 20611.
The thermal-stable β-fructofuranosidase produced by A. niger can be recycled to achieve continuous synthesis of FOS with high efficiency, providing a powerful and economical strategy for the industrial production of FOS.
在不进行固定化的情况下，通过循环利用黑曲霉中含有热稳定β-呋喃果糖苷酶的菌丝体细胞来实现低聚果糖（FOS）的连续生产。
热稳定β-呋喃果糖苷酶FopA-V1在组成型启动子PgpdA的控制下在黑曲霉ATCC 20611中成功表达。工程化黑曲霉菌株FV1-11产生了热稳定性提高的β-呋喃果糖苷酶，该酶在50°C下30小时仍保留初始活性的91.2%。然后将其菌丝体β-呋喃果糖苷酶循环用于FOS的合成。结果发现，该酶连续重复使用六个循环后仍具有初始活性的79.3%，而在亲本菌株ATCC 20611中仅检测到62.3%的β-呋喃果糖苷酶活性。同时，FV1-11连续六个循环后的FOS产量达到57.1%（w/w），而在ATCC 20611中仅检测到51.0%的FOS产量。
黑曲霉产生的热稳定β-呋喃果糖苷酶可循环利用以实现FOS的高效连续合成，为FOS的工业化生产提供了一种强大且经济的策略。
