Serratia sp. A5 and uses thereof

Abstract

The present invention relates to Serratia sp. A5 and applications thereof. The Serratia sp. A5 is preserved in the China General Microbiological Culture Collection Center on August 28, 2014, and the preservation number is CGMCC No.9621. According to the present invention, the Serratia sp. A5 is isolated from soil, the suitable growth temperature is 25-35 DEG C, the pH value is 7.0-7.5, and the Serratia sp. A5 has the lipase production ability; and the Serratia sp. A5 can be applied for degrading grease, relieving the inhibition effect of the grease in food waste anaerobic fermentation, increasing the biogas yield by 15-30%, and effectively increasing anaerobic fermentation hydrolysis and biogas production efficiency of other waste containing fat and the like or waste water, and further provides important significance for promotion of harmless, resource and energy utilization of organic waste.

Description

technical field

[0001] The invention relates to Serratia A5 and its application, in particular to the application of Serratia A5 in the degradation of kitchen waste, and belongs to the field of biotechnology. Background technique

[0002] According to statistics, Chinese cities generate more than 60 million tons of food waste every year, mainly composed of organic matter such as starch and animal fat. The treatment rate is less than 5%. The moisture content of food waste is as high as 80%, which is not suitable for direct use in several treatment methods such as incineration, landfill, composting and feed.

[0003] The country's overall thinking on the treatment of kitchen waste requires resourceful treatment, the development of a circular economy, and the realization of recycling. The anaerobic fermentation technology is an effective way of harmless, resourceful and energy utilization of organic waste, and is one of the effective ways to realize the mass consumption of ki...

Examples

Embodiment 1

[0019] Example 1 Serratia A5 Isolation and Preservation

[0020] Serratia A5 was isolated from soil by gradient dilution method.

[0021] The specific method is: Weigh 10 g (soil) soil from the place polluted by leftovers and leftovers around the cafeteria of the Hebei Academy of Sciences, add it to a triangular flask filled with 90 mL sterile water and glass beads, and shake it on a shaker for 30 min ( 150 r / min), serially diluted to make 10 -5 、10 -6 Dilute the suspension, draw 0.1 mL in each of them, add to the lipase primary screening medium (plus Tween-80) plate, spread evenly, and repeat 3 times for each treatment. Place the above petri dish at 25°C for constant temperature culture and transfer the single colony with large halo and fast growth to the slant of LB test tube, and store at 4°C.

[0022] Rescreening was carried out by enzyme activity assay. The isolated strains were placed in LB liquid medium and cultured in an incubator at 25 °C for 48-72 h. The ferme...

Embodiment 2

[0033] Example 2 Serratia A5 Enzyme Activity Assay

[0034] Serratia marcescens ( Serratia marcescens ), Serratia liquefaction ( Serratia liqufaciens ), Serratia odorifera ( Serratia odorifera ), Serratia rubrum ( Serratia rubidaea ) were respectively connected to LB liquid medium, cultured on a shaker at 30 °C for 48 h, the fermentation broth was centrifuged at 4 °C and 8000 r / min for 10 min, and the supernatant was taken to determine the lipase activity.

[0035] The determination methods are respectively adopted: National Standard GB / T 23535-2009.

[0036] Enzyme activity definition: 1 g1 mL liquid enzyme (or solid enzyme powder), under certain temperature and pH conditions (this example uses 40 ℃, pH 7.0), 1 min to hydrolyze the substrate (this patent uses olive oil as the substrate) Produce 1 umol of titratable fatty acid, that is, 1 enzyme activity unit, expressed in "U / mL (U / g)".

[0037]It can be seen from Table 1 that the lipase activity of Serratia A5 was ...

Embodiment 3~7

[0040] Example 3-7 Application of Serratia A5 in anaerobic fermentation of kitchen waste

[0041] Put the kitchen waste into the triangular flask first, set up 6 treatments, 5 experimental groups, insert Serratia A5 bacterial liquid at 5% to 20%, and the total number of bacteria in the bacterial liquid is ≥10 9 Individual / mL; 1 blank control group, no Serratia A5 was added. Shaker shaking culture for 13-24 hours, the oil in the experimental group completely disappeared, while the oil in the control group did not decrease.

[0042] Then a 5 L full-mix anaerobic fermentation device was used, and the above groups of kitchen waste were used as raw materials. The inoculum came from the normal fermentation biogas digester, and the inoculum amount was 25-30% (volume ratio), and the final anaerobic fermentation liquid TS was 5-5. 8% (TS, also known as dry matter concentration, refers to a certain amount of fermentation feed liquid placed in an oven at 105 ℃, dried to constant weig...

technical field

[0001] The invention relates to Serratia A5 and its application, in particular to the application of Serratia A5 in the degradation of kitchen waste, and belongs to the field of biotechnology. Background technique

[0002] According to statistics, Chinese cities generate more than 60 million tons of food waste every year, mainly composed of organic matter such as starch and animal fat. The treatment rate is less than 5%. The moisture content of food waste is as high as 80%, which is not suitable for direct use in several treatment methods such as incineration, landfill, composting and feed.

[0003] The country's overall thinking on the treatment of kitchen waste requires resourceful treatment, the development of a circular economy, and the realization of recycling. The anaerobic fermentation technology is an effective way of harmless, resourceful and energy utilization of organic waste, and is one of the effective ways to realize the mass consumption of ki...

Examples

Embodiment 1

[0019] Example 1 Serratia A5 Isolation and Preservation

[0020] Serratia A5 was isolated from soil by gradient dilution method.

[0021] The specific method is: Weigh 10 g (soil) soil from the place polluted by leftovers and leftovers around the cafeteria of the Hebei Academy of Sciences, add it to a triangular flask filled with 90 mL sterile water and glass beads, and shake it on a shaker for 30 min ( 150 r / min), serially diluted to make 10 -5 、10 -6 Dilute the suspension, draw 0.1 mL in each of them, add to the lipase primary screening medium (plus Tween-80) plate, spread evenly, and repeat 3 times for each treatment. Place the above petri dish at 25°C for constant temperature culture and transfer the single colony with large halo and fast growth to the slant of LB test tube, and store at 4°C.

[0022] Rescreening was carried out by enzyme activity assay. The isolated strains were placed in LB liquid medium and cultured in an incubator at 25 °C for 48-72 h. The ferme...

Embodiment 2

[0033] Example 2 Serratia A5 Enzyme Activity Assay

[0034] Serratia marcescens ( Serratia marcescens ), Serratia liquefaction ( Serratia liqufaciens ), Serratia odorifera ( Serratia odorifera ), Serratia rubrum ( Serratia rubidaea ) were respectively connected to LB liquid medium, cultured on a shaker at 30 °C for 48 h, the fermentation broth was centrifuged at 4 °C and 8000 r / min for 10 min, and the supernatant was taken to determine the lipase activity.

[0035] The determination methods are respectively adopted: National Standard GB / T 23535-2009.

[0036] Enzyme activity definition: 1 g1 mL liquid enzyme (or solid enzyme powder), under certain temperature and pH conditions (this example uses 40 ℃, pH 7.0), 1 min to hydrolyze the substrate (this patent uses olive oil as the substrate) Produce 1 umol of titratable fatty acid, that is, 1 enzyme activity unit, expressed in "U / mL (U / g)".

[0037]It can be seen from Table 1 that the lipase activity of Serratia A5 was ...

Embodiment 3~7

[0040] Example 3-7 Application of Serratia A5 in anaerobic fermentation of kitchen waste

[0041] Put the kitchen waste into the triangular flask first, set up 6 treatments, 5 experimental groups, insert Serratia A5 bacterial liquid at 5% to 20%, and the total number of bacteria in the bacterial liquid is ≥10 9 Individual / mL; 1 blank control group, no Serratia A5 was added. Shaker shaking culture for 13-24 hours, the oil in the experimental group completely disappeared, while the oil in the control group did not decrease.

[0042] Then a 5 L full-mix anaerobic fermentation device was used, and the above groups of kitchen waste were used as raw materials. The inoculum came from the normal fermentation biogas digester, and the inoculum amount was 25-30% (volume ratio), and the final anaerobic fermentation liquid TS was 5-5. 8% (TS, also known as dry matter concentration, refers to a certain amount of fermentation feed liquid placed in an oven at 105 ℃, dried to constant weig...

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