Limits...
Enhanced production of Ca²⁺-polymalate (PMA) with high molecular mass by Aureobasidium pullulans var. pullulans MCW.

Wang YK, Chi Z, Zhou HX, Liu GL, Chi ZM - Microb. Cell Fact. (2015)

Bottom Line: The medium containing only 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L corn steep liquor was found to be the most suitable for Ca(2+)-PMA production.During 10-L batch fermentation, 152.52 g/L of Ca(2+)-PMA in the culture and 8.6 g/L of cell dry weight were obtained within 96 h, leaving 4.5 g/L of reducing sugar in the fermented medium.Mw (the apparent molecular weight) of the purified PMA was 2.054 × 10(5) (g/moL) and the purified PMA was estimated to be composed of 1784 L-malic acids.

View Article: PubMed Central - PubMed

Affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, 266003, China. w84234102@sina.com.

ABSTRACT

Background: Polymalic acid (PMA) has many applications in food and medical industries. However, so far it has not been commercially produced by fermentation. Therefore, it is very important how to develop an economical process for a large scale production of PMA by one step fermentation.

Results: After over 200 strains of Aureobasidium spp. isolated from the mangrove systems in the South of China were screened for their ability to produce Ca(2+)-polymalate (PMA), it was found that Aureobasidium pullulans var. pullulans MCW strain among them could produce high level of Ca(2+)-PMA. The medium containing only 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L corn steep liquor was found to be the most suitable for Ca(2+)-PMA production. Then, 121.3 g/L of Ca(2+)-PMA was produced by A. pullulans var. pullulans MCW strain within 120 h at flask level. During 10-L batch fermentation, 152.52 g/L of Ca(2+)-PMA in the culture and 8.6 g/L of cell dry weight were obtained within 96 h, leaving 4.5 g/L of reducing sugar in the fermented medium. After purification of the Ca(2+)-PMA from the culture and acid hydrolysis of the purified Ca(2+)-PMA, HPLC analysis showed that A. pullulans var. pullulans MCW strain produced only one main component of Ca(2+)-PMA and the hydrolysate of the purified Ca(2+)-PMA was mainly composed of L-malic acid. Mw (the apparent molecular weight) of the purified PMA was 2.054 × 10(5) (g/moL) and the purified PMA was estimated to be composed of 1784 L-malic acids.

Conclusions: It was found that A. pullulans var. pullulans MCW strain obtained in this study could yield 152.52 g/L of Ca(2+)-PMA within the short time, the produced PMA had the highest molecular weight and the medium for production of Ca(2+)- PMA by this yeast was very simple.

No MeSH data available.


Related in: MedlinePlus

The time course of Ca2+-PMA production (filled diamond), cell growth (filled square) and the changes in the amount of reducing sugar (filled triangle) during the 10-L fermentation. Data are given as mean ± SD, n = 3.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4528779&req=5

Fig5: The time course of Ca2+-PMA production (filled diamond), cell growth (filled square) and the changes in the amount of reducing sugar (filled triangle) during the 10-L fermentation. Data are given as mean ± SD, n = 3.

Mentions: In order to know if the Ca2+-PMA production from glucose and CaCO3 by one step fermentation can be repeated in the fermentor, the 10-L fermentation was carried out as described in “Methods”. During the 10-L fermentation, the changes in Ca2+-PMA titer, cell mass, and reducing sugar concentration were monitored. The results in Fig. 5 showed that during the 10-L fermentation, 152.52 g/L of Ca2+-PMA in the fermented medium was achieved from 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L CSL and the biomass in the culture was 8.59 g/L within 96 h, leaving 4.5 g/l of reducing sugar in the fermented medium. It also can be observed from the data in Fig. 5 that a Ca2+-PMA yield of 1.13 g/g of glucose, a volumetric Ca2+-PMA productivity of 1.59 g/L/h and a specific Ca2+-PMA productivity of 0.012 g/g/h were reached within 96 h of the fermentation, demonstrating that the titer, yield, and productivity of the Ca2+-PMA by this yeast strain MCW were very high and the fermentation period was very short. However, after 96 h of the fermentation, the titer of Ca2+-PMA was decreased and cell growth was still continuously increased (Fig. 5). This may be due to that the Ca2+-PMA was degraded after 96 h of the fermentation and the produced malate was used for cell growth according to the metabolism pathway of PMA in Fig. 4. In our previous study [13], 118.3 g/L of Ca2+-PMA was yielded by Aureobasidium sp. P6 within 168 h, the volumetric productivity was 0.67 g/L/h and the yield was 0.87 g/g [13]. In the 10-L fermentor, A. pullulans ZD-3d isolated from the terrestrial source produced a high PMA concentration (57.2 g/L) and a volumetric productivity (0.35/L/h) was achieved within 160 h when the fermentation medium contained 120.0 g/L of glucose and 30.0 g/L of CaCO3 [11]. In another study [9], A. pullulans ipe-1 could produce 37.9 g/L of PMA and a yield of 0.3 g/g was reached. Around 63.2 g/L of PMA with a volumetric productivity of 1.15 g/L/h was obtained by the same yeast strain during the repeated-batch cultivation [9]. When A. pullulans CBS 591.75 was grown in the stirred-tank reactor, it could produce 9.8 g/L of PMA within 9 days and a yield of 0.11 g/g was got [18]. A. pullulans strain ZX-10 grown in the medium with 120.0 g/L of glucose produced 50.0 g/L of PMA during the batch fermentation and the high productivity was 0.61 g/L/h in a free-cell fermentation in a stirred-tank bioreactor [10]. This demonstrated that A. pullulans var. pullulans MCW strain used in this study may be the most suitable yeast strain for Ca2+-PMA production from glucose on a large scale in industry because it could produce much more Ca2+-PMA than any other yeast strains reported so far and the production medium was very simple (Figs. 2, 3 and 5).Fig. 5


Enhanced production of Ca²⁺-polymalate (PMA) with high molecular mass by Aureobasidium pullulans var. pullulans MCW.

Wang YK, Chi Z, Zhou HX, Liu GL, Chi ZM - Microb. Cell Fact. (2015)

The time course of Ca2+-PMA production (filled diamond), cell growth (filled square) and the changes in the amount of reducing sugar (filled triangle) during the 10-L fermentation. Data are given as mean ± SD, n = 3.
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4528779&req=5

Fig5: The time course of Ca2+-PMA production (filled diamond), cell growth (filled square) and the changes in the amount of reducing sugar (filled triangle) during the 10-L fermentation. Data are given as mean ± SD, n = 3.
Mentions: In order to know if the Ca2+-PMA production from glucose and CaCO3 by one step fermentation can be repeated in the fermentor, the 10-L fermentation was carried out as described in “Methods”. During the 10-L fermentation, the changes in Ca2+-PMA titer, cell mass, and reducing sugar concentration were monitored. The results in Fig. 5 showed that during the 10-L fermentation, 152.52 g/L of Ca2+-PMA in the fermented medium was achieved from 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L CSL and the biomass in the culture was 8.59 g/L within 96 h, leaving 4.5 g/l of reducing sugar in the fermented medium. It also can be observed from the data in Fig. 5 that a Ca2+-PMA yield of 1.13 g/g of glucose, a volumetric Ca2+-PMA productivity of 1.59 g/L/h and a specific Ca2+-PMA productivity of 0.012 g/g/h were reached within 96 h of the fermentation, demonstrating that the titer, yield, and productivity of the Ca2+-PMA by this yeast strain MCW were very high and the fermentation period was very short. However, after 96 h of the fermentation, the titer of Ca2+-PMA was decreased and cell growth was still continuously increased (Fig. 5). This may be due to that the Ca2+-PMA was degraded after 96 h of the fermentation and the produced malate was used for cell growth according to the metabolism pathway of PMA in Fig. 4. In our previous study [13], 118.3 g/L of Ca2+-PMA was yielded by Aureobasidium sp. P6 within 168 h, the volumetric productivity was 0.67 g/L/h and the yield was 0.87 g/g [13]. In the 10-L fermentor, A. pullulans ZD-3d isolated from the terrestrial source produced a high PMA concentration (57.2 g/L) and a volumetric productivity (0.35/L/h) was achieved within 160 h when the fermentation medium contained 120.0 g/L of glucose and 30.0 g/L of CaCO3 [11]. In another study [9], A. pullulans ipe-1 could produce 37.9 g/L of PMA and a yield of 0.3 g/g was reached. Around 63.2 g/L of PMA with a volumetric productivity of 1.15 g/L/h was obtained by the same yeast strain during the repeated-batch cultivation [9]. When A. pullulans CBS 591.75 was grown in the stirred-tank reactor, it could produce 9.8 g/L of PMA within 9 days and a yield of 0.11 g/g was got [18]. A. pullulans strain ZX-10 grown in the medium with 120.0 g/L of glucose produced 50.0 g/L of PMA during the batch fermentation and the high productivity was 0.61 g/L/h in a free-cell fermentation in a stirred-tank bioreactor [10]. This demonstrated that A. pullulans var. pullulans MCW strain used in this study may be the most suitable yeast strain for Ca2+-PMA production from glucose on a large scale in industry because it could produce much more Ca2+-PMA than any other yeast strains reported so far and the production medium was very simple (Figs. 2, 3 and 5).Fig. 5

Bottom Line: The medium containing only 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L corn steep liquor was found to be the most suitable for Ca(2+)-PMA production.During 10-L batch fermentation, 152.52 g/L of Ca(2+)-PMA in the culture and 8.6 g/L of cell dry weight were obtained within 96 h, leaving 4.5 g/L of reducing sugar in the fermented medium.Mw (the apparent molecular weight) of the purified PMA was 2.054 × 10(5) (g/moL) and the purified PMA was estimated to be composed of 1784 L-malic acids.

View Article: PubMed Central - PubMed

Affiliation: College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, 266003, China. w84234102@sina.com.

ABSTRACT

Background: Polymalic acid (PMA) has many applications in food and medical industries. However, so far it has not been commercially produced by fermentation. Therefore, it is very important how to develop an economical process for a large scale production of PMA by one step fermentation.

Results: After over 200 strains of Aureobasidium spp. isolated from the mangrove systems in the South of China were screened for their ability to produce Ca(2+)-polymalate (PMA), it was found that Aureobasidium pullulans var. pullulans MCW strain among them could produce high level of Ca(2+)-PMA. The medium containing only 140.0 g/L glucose, 65.0 g/L CaCO3 and 7.5 g/L corn steep liquor was found to be the most suitable for Ca(2+)-PMA production. Then, 121.3 g/L of Ca(2+)-PMA was produced by A. pullulans var. pullulans MCW strain within 120 h at flask level. During 10-L batch fermentation, 152.52 g/L of Ca(2+)-PMA in the culture and 8.6 g/L of cell dry weight were obtained within 96 h, leaving 4.5 g/L of reducing sugar in the fermented medium. After purification of the Ca(2+)-PMA from the culture and acid hydrolysis of the purified Ca(2+)-PMA, HPLC analysis showed that A. pullulans var. pullulans MCW strain produced only one main component of Ca(2+)-PMA and the hydrolysate of the purified Ca(2+)-PMA was mainly composed of L-malic acid. Mw (the apparent molecular weight) of the purified PMA was 2.054 × 10(5) (g/moL) and the purified PMA was estimated to be composed of 1784 L-malic acids.

Conclusions: It was found that A. pullulans var. pullulans MCW strain obtained in this study could yield 152.52 g/L of Ca(2+)-PMA within the short time, the produced PMA had the highest molecular weight and the medium for production of Ca(2+)- PMA by this yeast was very simple.

No MeSH data available.


Related in: MedlinePlus