title: Trehalose accumulation from cassava starch and release by a highly thermosensitive and permeable mutant of Saccharomycopsis fibuligera.
abstract: Highly thermosensitive and permeable mutants are the mutants from which intracellular contents can be released when they are incubated both in low osmolarity water and at non-permissive temperature (usually 37°C). After mutagenesis by using nitrosoguanidine, a highly thermosensitive and permeable mutant named A11-b was obtained from Saccharomycopsis fibuligera A11-12, a trehalose overproducer in which the acid protease gene has been disrupted. Of the total trehalose, 73.8% was released from the mutant cells suspended in distilled water after they had been treated at 37°C overnight. However, only 10.0% of the total trehalose was released from the cells of S. fibuligera A11-12 treated under the same conditions. The cell volume of the mutant cells suspended in distilled water and treated at 37°C overnight was much bigger than that of S. fibuligera A11-12 treated under the same conditions. The cell growth and trehalose accumulation of the mutant were almost the same as those of S. fibuligera A11-12 during the cultivation at the flask level and in a 5-l fermentor. Both could accumulate around 28.0% (w/w) trehalose from cassava starch. After purification, the trehalose crystal from the aqueous extract of the mutant was obtained.
authors.affiliation: Unesco Chinese Center of Marine Biotechnology, Ocean University of China, Yushan Road, No. 5, 266003, Qingdao, Shandong, China.
authors.forename: Dong-Sheng
authors.initials: DS
authors.lastname: Wang
authors.forename: Shou-Feng
authors.initials: SF
authors.lastname: Zhao
authors.forename: Ming-Xin
authors.initials: MX
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Zhen-Ming
authors.initials: ZM
authors.lastname: Chi
mesh_terms: D005285:Fermentation; D002365:Manihot; D016296:Mutagenesis; D012442:Saccharomycopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D013213:Starch / Q000378:metabolism*; D013696:Temperature; D014199:Trehalose / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D013213:Starch; D014199:Trehalose