Dataset describing ethanol and 1,2-propanediol production by a stenothermal moderately thermophilic anaerobe, Clostridium strain AK1

The dataset details the fermentation of D-glucose, L-rhamnose, and L-fucose and their end-product formation by the moderate thermophile Clostridium strain AK1 (DSM 18778) as related to the work described in “Propanediol from L-rhamnose using the moderately thermophilic Clostridium strain AK1” [1]. The influence of culture conditions on end product formation from D-glucose and L-rhamnose by AK1 was investigated in batch culture. Strain AK1 was cultivated at initial substrate concentrations varying from 0 to 60 mM and initial pH values varying from 4.5 to 8.5. Additionally different cultivation temperatures (30–65 °C), the influence of liquid-gas phase ratio as well as different phosphate concentrations on growth were investigated.


a b s t r a c t
The dataset details the fermentation of D-glucose, L-rhamnose, and L-fucose and their end-product formation by the moderate thermophile Clostridium strain AK1 (DSM 18778) as related to the work described in "Propanediol from L-rhamnose using the moderately thermophilic Clostridium strain AK1" [1]. The influence of culture conditions on end product formation from D-glucose and L-rhamnose by AK1 was investigated in batch culture. Strain AK1 was cultivated at initial substrate concentrations varying from 0 to 60 mM and initial pH values varying from 4.5 to 8.5. Additionally different cultivation temperatures (30-65°C), the influence of liquid-gas phase ratio as well as different phosphate concentrations on growth were investigated. & 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Substrate, growth temperature, initial substrate concentration, initial pH, liquid-gas phase ratio, initial phosphate concentration Experimental features Data shows fermentation products from D-glucose, L-rhamnose, and L-fucose under different culture parameters. Major end products being ethanol (from glucose) and 1,2-PD from L-rhamnose. L-fucose was not fermented. Data source location University of Akureyri, Akureyri, Iceland Data accessibility Data is included in this article Related research article Ingvadottir et al. [1] Value of the data

Specifications
The data presents ethanol and 1,2-propanediol fermentation from a stenothermal moderately thermophilic anaerobe isolated from a geothermal feature in Iceland.
This data set could be of value for comparing fermentation yields and the impact of key culture parameters on ethanol and 1,2-propanediol producing microorganisms.
Could be used as a reference organism for studying an overlooked environmental niche (moderate temperature hot springs).

Data
Clostridium strain AK1 ferments D-glucose and L-rhamnose with ethanol and 1,2-propanediol (1,2-PD) being the major end-products, respectively (Table 1). Table 2 shows the influence of temperature on the fermentation of D-glucose and L-rhamnose while the effect of pH from pH 4.8 to 7.8 is shown in Table 3. The impact of liquid-gas phase ratio in culture bottles on D-glucose and L-rhamnose fermentation is summarized in Table 4. D-Glucose and L-rhamnose degradation on various initial phosphate concentrations resulted in the same end-product formation as before as summarized in Table 5.

General methods
Yeast extract was obtained from Difco. L-Fucose was obtained from Dextra (Reading, UK). All other reagents were obtained from Sigma-Aldrich. Nitrogen gas was acquired from AGA and contained less than 5 ppm O 2 .

Microorganism and cultivation
Clostridium strain AK1 (DSM 18778) was isolated from the laboratory of the authors as described in [2] and reobtained from Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSMZ). Strain AK1 was cultivated in serum bottles using the in Basal Mineral (BM) medium prepared as previously described [3]; BM consisted of (per liter): NaH 2 PO 4 Á 2H 2 O 3.04 g, Na 2 HPO 4 Á 2H 2 O 5.43 g, NH 4 Cl 0.3 g, NaCl 0.3 g, CaCl 2 Á 2H 2 O 0.11 g, MgCl 2 Â 6H 2 O 0.1 g, yeast extract 2.0 g, resazurin 1 mg, trace element solution 1 mL, vitamin solution (DSM141) 1 mL, and NaHCO 3 0.8 g. The trace element solution consisted of the following on a per liter basis: FeCl 2 Â 4 H 2 O 2.0 g, EDTA 0.5 g, CuCl 2 0.03 g, H 3 BO 3 , ZnCl 2 ,              [4,5] and autoclaved for 60 min. All other components of the medium were added separately through filter (0.45 mm) sterilized solutions. All experiments were conducted at 50°C and at pH of 7.0 with a liquid-gas (L-G) ratio of 1:1 unless specifically stated otherwise. In all cases, growth experiments were performed in triplicate without agitation.

Effect of initial substrate concentration
To investigate the effect of different initial glucose and rhamnose concentrations on growth the strain was cultivated at 10, 20, 40 and 60 mM of each sugar.

Effect of pH on fermentation end products
To investigate the effect of pH on growth the strain was cultivated at pH ranging from pH 4.0 to 9.0 with 0.5 pH unit intervals. End products were determined after 5 days of incubation.

Effect of temperature on fermentation end products
To investigate the effect of temperature on growth the strain was cultivated at 35°C to 65°C in 5°C intervals. End products were determined after 5 days of incubation.

Effect of liquid-gas phase ratio
Strain AK 1 was cultivated in serum bottles (57 mL nominal volume) were filled with either 4.5, 13.4, 26.5, 36.0, or 45.0 mL of BM medium to give L-G values of 0.09, 0.34, 1.00, 2.12, and 5.62, respectively.

Effect of initial phosphate concentration
Phosphate-free yeast extract was prepared according to the method described by [6] and used for the preparation of phosphate-free BM. The phosphate concentration of the resultant yeast extracted was verified colorimetrically and was below the limit of detection of the assay. Strain AK1 was cultivated on 10 mM of either D-glucose or L-rhamnose with phosphate added from syringe-filtered stock bottles. Phosphate concentrations ranging from 0 (control) and 0.01 mM to 25 mM were investigated.

Analytical methods
Hydrogen, volatile fatty acids and alcohols were quantified by gas chromatography as described earlier [2]. D-Glucose was quantified using the anthrone method [7] with the modifications described by previously [8]. Methylpentoses and 1,2-PD were analysed using colorimetric methods [9,10] modified for microplates as described earlier [8]. Lactic acid was quantified using the method of [11] with modification; Briefly, 50 mL of sample was placed in a 1.5 mL Eppendorf tube, followed by the addition of 300 mL of concentrated sulfuric acid and incubated in a water bath (100°C) for 10 min. After cooling to RT, 5 mL of 4% (w/v) CuSO 4 reagent were added followed by 10 mL of 1.5% (w/v) p-phenylphenol in 95% (v/v) ethanol. The mixture was vortexed and allowed to incubate at room temperature for 30 minutes. 300 mL of sample was then transferred into a microtiter plate and read at 570 nm against a water blank. Phosphate concentrations were determined spectrophotometrically according to Olsen and Summers [12] in microtiter plates read in a Bioscreen C.
Optical density was measured at 600 nm with a Shimadzue UV-1800 UV-Visible spectrophotometer with cuvetted (l ¼ 1 cm) against a water blank.

Transparency document. Supporting information
Transparency data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.dib.2018.08.088.