Additional file 1 of A facile process for adipic acid production in high yield by oxidation of 1,6-hexanediol using the resting cells of Gluconobacter oxydans
Creators: name: Pyo, Sang-Hyun
name: Sayed, Mahmoud
name: Örn, Oliver Englund
name: Amorrortu Gallo, Jorge
name: Fernandez Ros, Nídia
name: Hatti-Kaul, Rajni
Publisher: name: figshare
Year: 2022
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Genetics
subject: Pharmacology
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Inorganic Chemistry

description: Additional file 1: Scheme S1. Commercial adipic acid production from petroleum-derived benzene through cyclohexane by chemical catalysis, and its use in the production of Nylon 6,6. Oxidation of cyclohexane using Co catalyst (cobalt- (II) naphthenate) and air as an oxidant to KA oil (ketone-alcohol oil), a mixture of cyclohexanone and cyclohexanol, is typically conducted at low conversions (3 to 8%) to maintain high selectivity (70–90%), necessitating extensive feed recycling and huge capital costs [19]. Further oxidation of KA oil to adipic acid occurs under harsh conditions using nitric acid, with coproduction of undesired N2O. Scheme S2. An integrated microbial-chemical route for the production of biobased 6hydroxyhexanoic acid (6-HHA), adipic acid (AA), and ε-caprolactone (ε-CL) via 5hydroxymethylfurfural (5-HMF) and 1,6-hexanediol (1,6-HD) [20]. Scheme S3. Possible oxidation pathway of 1,6-hexanediol to adipic acid via different oxidative intermediates. Figure S1. GC chromatograms on the 1,6-HD oxidation to AA at time 6, 12 h and 30 h by G. oxydans 50049. 1. hexan-dial, 2. 6-hydroxyhexanal, 3. 1,6-hexanediol, 4. 6oxohexanoic acid, 5. 6-hydroxyhexanoic acid, 6. Adipic acid. Figure S2. Mass data determined by GC–MS on the microbial oxidation of 10 g/L 1,6hexanediol (1,6-HD) to adipic acid (AA). The numbered compounds in Figure S1 were confirmed by Mass; 1. hexan-dial, 2. 6-hydroxyhexanal, 3. 1,6-hexanediol, 4. 6oxohexanoic acid, 5. 6-hydroxyhexanoic acid, 6. Adipic acid. Figure S3. Effect of aeration on the oxidation of 10 g/L 1,6-hexanediol to adipic acid at 30 °C for 24 h without pH control by G. oxydans 50049. (A) With the cells grown under different aeration conditions either through sparging of different air volumes (0.5–2 L/min) or with fixed DO (20–40%) by controlling the stir rate. Figure S4. Solubility of adipic acid in 0.1 M PBS at pH 5.5, 5 and 4.5; In 5 mL 0,1 M PBS buffer (pH 8,3) 1500 or 2000 mg of adipic acid was resuspended and the pH was adjusted with 5 M NaOH to pH 4.5 and 5 for the 150 mg adipic acid and to pH 5 for the 2000 mg. The volume was adjusted to 10 mL with PBS buffer of respective pH and the solution incubated at 30 °C for 2 h to allow the adipic acid saturate the buffer. Figure S5. Parameters for fed-batch biotransformation of 1,6-HD to AA in 1 L working volume in 3 L bioreactor.