Production of theabrownins using a crude fungal enzyme concentrate.
Theabrownins were produced from infusions of sun-dried green tea leaves using a crude enzyme concentrate of Aspergillus tubingensis TISTR 3647. This fungus had been isolated from a solid state fermentation of Pu-erh type tea. The crude enzyme concentrate contained activities of peroxidase, catechol oxidase and laccase. The enzyme concentrate effectively oxidized the phenolic compounds in green tea infusion to theabrownins. A theabrownins concentration of 56.0g/L was obtained in 44h. The reaction mixture contained the green tea infusion and crude enzyme concentrate in the volume ratio of 1: 0.205. The tea infusion had been produced using 200g of tea leaves per liter of distilled water. The reaction was carried out in a stirred bioreactor at 37°C with an aeration rate of 1 vvm, an agitation speed of 250rpm and a controlled pH of 7.0. Peroxidase, catechol oxidase, and laccase acted synergistically to convert the phenolic compounds in green tea infusion to theabrownins. Previously, theabrownins had been produced from green tea infusions only by using live fungal cultures. Production using the microorganism-free enzyme concentrate was comparable to production using the fungus A. tubingensis TISTR 3647. The proposed novel production process using the fungal crude enzymes and green tea infusion, offers a more controlled, reproducible and highly productive option for commercial production of theabrownins.
Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand.
Qiuping
Q
Wang
Department of Food Quality and Safety, Faculty of Food Science and Technology, Yunnan Agricultural University, Heilong Tan, Kunming, Yunnan 650201, China.
Jiashun
J
Gong
School of Engineering, Massey University, Private Bag 11 222, Palmerston North, New Zealand.
Yusuf
Y
Chisti
Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 50 Ngam Wong Wan Road, Chatuchak, Bangkok 10900, Thailand; Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Kasetsart University, CASTNAR, NRU-KU, Chatuchak, Bangkok 10900, Thailand, Thailand. Electronic address: sarote.s@ku.ac.th.
Sarote
S
Sirisansaneeyakul
D001230:Aspergillus / Q000201:enzymology* / Q000378:metabolism; D019149:Bioreactors / Q000382:microbiology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D005656:Fungal Proteins / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
D005656:Fungal Proteins; D010936:Plant Extracts; D013662:Tea; C569455:theabrownin; D002392:Catechin; D010088:Oxidoreductases
Aspergillus tubingensis; Enzymatic production; Microbial fermentation; Theabrownins