CN102154378A

CN102154378A - Fermentation production method of xylitol

Info

Publication number: CN102154378A
Application number: CN2010105600070A
Authority: CN
Inventors: 薛亮; 唐浩; 崔玮
Original assignee: Anhui BBCA Fermentation Technology Engineering Research Co Ltd
Current assignee: Anhui BBCA Fermentation Technology Engineering Research Co Ltd
Priority date: 2010-11-18
Filing date: 2010-11-18
Publication date: 2011-08-17
Anticipated expiration: 2030-11-18
Also published as: CN102154378B

Abstract

The invention provides a method for improving the fermentation yield of xylitol by adding metal nickel ions. The nickel ions are added to a yeast fermentation culture medium to a preferential concentration of 40 mu mol/L so that the conversion rate of the fermentation production of xylitol by taking xylose as a substrate reaches 70.4%, and the yield reaches 35.2 g/L. The method provided by the invention is easy to implement, low in cost and little in energy consumption, and can be applied to industrial large-scale fermentation production of xylitol.

Description

A kind of fermentation method for producing of Xylitol

Technical field

The present invention relates to the microbial fermentation field, specifically, relate to a kind of by in substratum, adding the method that nickel ion improves xylitol fermentation output.

Background technology

Xylitol is a kind of important five-carbon sugar alcohol, is the crystallinity white powder, is the normal intermediate of xylose metabolism, extensively is present in the plants such as the group food of cereal, fruit, vegetables, mushroom and timber, corn cob, straw.Xylitol is a sweeting agent the sweetest in the polyvalent alcohol, and its sugariness and sucrose are suitable, but its heat only is about 2/3 of a sucrose.Xylitol metabolism does not in vivo need the participation of Regular Insulin, and blood glucose value is raise, and can make diabetics's sweetening agent and auxiliary therapeutical agent.Simultaneously, Xylitol also have the liver function of improvement, prevent carious tooth, effect such as fat-reducing.In addition, Xylitol is as being a kind of polyvalent alcohol, and its hygroscopic characteristics can be used as the moistening adjustment agent of makeup, and skin is had no stimulation.

At present, the suitability for industrialized production of Xylitol is mainly by chemical hydrogenation method, critical process is raw material → hydrolysis → neutralization → concentrated → decolouring → ion-exchange → concentrated → hydrogenation → concentrated → crystallization → separation → packing, this method production technique is long, operation easier is big, the hydrogenation operation needs the High Temperature High Pressure power consumption serious, and easily produces bigger pollution, increases environmental protection treatment pressure.Thereby cause the production cost of Xylitol too high, hold at high price.

The Production by Microorganism Fermentation Xylitol can be avoided violent chemical reaction, and the fermentation condition gentleness does not need special corrosion-resistant anti-high-tension apparatus, and purification procedures is simple, can significantly reduce production costs, and is considered to have most the Xylitol production method of development potentiality.Occurring in nature can utilize the microorganism of wood sugar generation Xylitol a lot, comprises bacterium (as M.smegmatis), mould (as P.albertensis), yeast etc.

Summary of the invention

The fermentation method for producing that the purpose of this invention is to provide a kind of Xylitol.

In order to realize the object of the invention, the fermentation method for producing of a kind of Xylitol of the present invention, its be with wood sugar as fermentation substrate, in fermention medium, add microelement nickel, by the zymic xylitol zymolysis production.

Used fermentative medium formula is wood sugar 4-10%, glucose 0.5-1.5%, corn steep liquor 0.4-1.2%, urea 0.02-0.1%, single nickel salt 20-80 μ mol/L, pH4.0.Preferably sulfuric acid nickel 20-40 μ mol/L.

More preferably, fermentative medium formula is wood sugar 5%, glucose 1%, corn steep liquor 0.8%, urea 0.06%, single nickel salt 40 μ mol/L, pH4.0.

The used bacterial classification of fermentative production is a yeast, yeast in the preferred mycocandida, more preferably, be candida tropicalis (C.tropicalis), not basic candiyeast (C.mogii), level and smooth candiyeast (C.parasilosis) or Ji Lemeng ground candiyeast (C.guilliermondii).

The invention has the advantages that: by in fermention medium, adding Ni ²⁺Improve the output of Xylitol, and do not added Ni ²⁺The fermentation result compare, Xylitol output can reach more than the 35.g/L, the transformation efficiency of wood sugar can reach more than 70%, fermentation period foreshortens in the 23h.Method provided by the invention is simple, and cost is low, and less energy consumption can be used for the large-scale industrialization xylitol zymolysis production.

Description of drawings

Fig. 1 is preferred embodiment Ni of the present invention ²⁺Concentration is to the influence of C.tropicalis growth.

Fig. 2 is preferred embodiment Ni of the present invention ²⁺Concentration is to the influence of xylitol fermentation output.

Embodiment

Following examples are used to illustrate the present invention, but are not used for limiting the scope of the invention.

Embodiment 1 Ni ²⁺Concentration is to the influence of thalli growth

Actication of culture: from-80 ℃ of refrigerators, take out candida tropicalis (Candida tropicalis CICC1316, purchase in Chinese industrial microbial strains preservation center) glycerol stock, streak inoculation is cultivated activation in 30 ℃ on YPD (Yeast protein peptone dextrose culture-medium) plate culture medium.Picking list bacterium colony activates twice continuously.

The seed flask culture: picking list bacterium colony from the flat board, be inoculated in the 500mL that 100ml seed culture medium (0.25% peptone, pH 4.0, autoclaving for 2% glucose, 0.15% yeast powder) is housed and shake in the bottle, culture condition is 30 ℃, 180rpm, 24h.

Shake flask fermentation experiment: transfer seed liquor to fermention medium by 10% inoculum size, the final component that makes fermented liquid is wood sugar 5%, glucose 1%, corn steep liquor 0.8%, urea 0.06%, the pH value transfers to 4.0, and liquid amount is fermented liquid 100mL in every 500mL triangular flask.To each reaction system power NiSO ₄Make Ni ²⁺Final concentration reach 0,40,80,120,160,200 μ mol/L respectively.This substratum need not autoclaving, can be directly used in fermentation after preparation is finished.Fermentation condition is 30 ℃, 250rpm.Every 4h sampling is once measured OD _600nm, the result shows, Ni ²⁺When concentration was 40,80 μ mol/L, thalli growth was unaffected or the speed of growth is slightly fast, and the result as shown in Figure 1.

Embodiment 2 Ni ²⁺Concentration is to the influence of xylitol fermentation output

Xylitol Determination on content:, get supernatant and do high-performance liquid chromatogram determination Xylitol content with the centrifugal cell precipitation that goes of fermented liquid.Chromatographic condition is: chromatographic instrument is Agilent 1200 HPLC (Agilent 1200 chromatographic working stations), and chromatographic column is the 87H3 ion-exchange chromatography, and chromatographic column temperature is 60 ℃, and detector is a differential refraction detector, and moving phase is the H of 4mmol/L ₂SO ₄, flow velocity 0.6mL/min, setting each sample size is 25 μ L.

The method of pressing among the embodiment 1 is cultivated seed, be inoculated in the fermention medium by 10% inoculum size, make the final component concentration of fermention medium be respectively wood sugar 5%, glucose 1%, corn steep liquor 0.8%, urea 0.06%, the pH value transfers to 4.0, adds Ni respectively in each fermentation system ²⁺It is 0,20,40,60,80 μ mol/L that ion makes ultimate density, and liquid amount is 100mL/500mL.30 ℃ of following 250rpm shake flask fermentations, every 4h sampling is once measured Xylitol content, and when nickel ion concentration was 40 μ mol/L, the yield of Xylitol was the highest, reaches 34.8g/L, and transformation efficiency is 69.6%, and the result is as shown in Figure 2.

The experiment of embodiment 3 5L ferment tanks

In the 5L fermentor tank, optimizing fermention medium (optimization fermention medium component: wood sugar 5%, glucose 1%, corn steep liquor 0.8%, urea 0.06%, single nickel salt 40 μ mol/L) with 10% inoculum size inoculation cultivates, in the culturing process, initially with the 0.5vvm air flow, mixing speed 300rpm, 30 ℃ of culture temperature, pH is about 4.0 before kind, utilize 25% ammoniacal liquor automatic control pH to 4.0 in the culturing process, temp autocontrolled to 30 ℃, air flow and mixing speed to be adjusted in per 2 hours, the control dissolved oxygen is more than 40%, after fermentation 10 hours, work as OD _660nmReach about 20, transfer little aerobic fermentation to, air flow drops to 0.05vvm, mixing speed drops to 200rpm, and through 13 hours fermentation, the output of last Xylitol reached 35.2g/L again, the transformation efficiency of wood sugar reaches 70.4%, and the whole cycle of xylitol fermentation foreshortens to 23h.

Do not add under the situation of single nickel salt in optimizing fermention medium, compare fermenting experiment according to the fermentation parameter of present embodiment, xylitol fermentation yield maximum is 30.6g/L when 31h, and the transformation efficiency of wood sugar is 61.2%.This shows, improved the output and the transformation efficiency of Xylitol by in fermention medium, adding nickel ion, and shortened fermentation period.

Though above the present invention is described in detail with a general description of the specific embodiments, on basis of the present invention, can make some modifications or improvements it, this will be apparent to those skilled in the art.Therefore, these modifications or improvements all belong to the scope of protection of present invention without departing from theon the basis of the spirit of the present invention.

Claims

1. the fermentation method for producing of an Xylitol is characterized in that, as fermentation substrate, adds microelement nickel with wood sugar in fermention medium, by the zymic xylitol zymolysis production.

2. method according to claim 1 is characterized in that, fermentative medium formula is wood sugar 4-10%, glucose 0.5-1.5%, corn steep liquor 0.4-1.2%, urea 0.02-0.1%, single nickel salt 20-80 μ mol/L, pH4.0.

3. method according to claim 2 is characterized in that, fermentative medium formula is wood sugar 4-10%, glucose 0.5-1.5%, corn steep liquor 0.4-1.2%, urea 0.02-0.1%, single nickel salt 20-40 μ mol/L, pH4.0.

4. according to claim 2 or 3 described methods, it is characterized in that fermentative medium formula is wood sugar 5%, glucose 1%, corn steep liquor 0.8%, urea 0.06%, single nickel salt 40 μ mol/L, pH4.0.

5. according to each described method of claim 1-4, it is characterized in that described yeast is the yeast in the mycocandida.

6. according to each described method of claim 5, it is characterized in that described yeast is candida tropicalis (C.tropicalis), not basic candiyeast (C.mogii), level and smooth candiyeast (C.parasilosis) or Ji Lemeng ground candiyeast (C.guilliermondii).