caa a22 4500 605502595 CHVBK 20210128100606.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00253-015-6958-6 doi (NATIONALLICENCE)springer-10.1007/s00253-015-6958-6 Enhancing the vitamin B12 production and growth of Propionibacterium freudenreichii in tofu wastewater via a light-induced vitamin B12 riboswitch [Elektronische Daten] [Yue Yu, Xuan Zhu, Yubiao Shen, Huanghong Yao, Peiheng Wang, Kun Ye, Xiaofeng Wang, Qing Gu] The vitamin B12-dependent riboswitch is a crucial factor that regulates gene transcription to mediate the growth of and vitamin B12 synthesis by Propionibacterium freudenreichii. In this study, the effect of various wavelengths of light on the growth rate and vitamin B12 synthesis was studied. Red, green, and blue light-emitting diodes (LEDs) were selected, and a dark condition was used as the control. The microorganism growth rate was measured using a spectrophotometer and plate counting, while the vitamin B12 content was determined using an HPLC-based method. The optical density at 600nm (OD600) values indicated that P. freudenreichii grew better under the continuous and discontinuous blue light conditions. Moreover, under the blue light condition, P. freudenreichii tended to have a higher growth rate (0.332h−1) and vitamin B12 synthesis (ca. 10μg/mL) in tofu wastewater than in dark conditions. HPLC analysis also showed that more methylcobalamin was produced under the blue light conditions than in the other conditions. The cbiB gene transcription results showed that blue light induced the synthesis of this vitamin B12 synthesis enzyme. Moreover, the results of inhibiting the expression of green fluorescent protein indicated that blue light removed the inhibition by the vitamin B12-dependent riboswitch. This method can be used to reduce fermentation time and produce more vitamin B12 in tofu wastewater. Springer-Verlag Berlin Heidelberg, 2015 Blue light nationallicence Vitamin B12 nationallicence P. freudenreichii nationallicence Riboswitch nationallicence Yu Yue Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Zhu Xuan Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Shen Yubiao Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Yao Huanghong Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Wang Peiheng Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Ye Kun Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Wang Xiaofeng Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Gu Qing Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/24(2015-12-01), 10481-10488 0175-7598 99:24<10481 2015 99 253 https://doi.org/10.1007/s00253-015-6958-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-015-6958-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yu Yue Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Zhu Xuan Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Shen Yubiao Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Yao Huanghong Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Wang Peiheng Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Ye Kun Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Wang Xiaofeng Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 700 1- Gu Qing Zhejiang Gongshang University, School of Food Science and Biotechnology, No. 18 Xuezheng Str., 310018, Hangzhou, Zhejiang Province, China aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/24(2015-12-01), 10481-10488 0175-7598 99:24<10481 2015 99 253