DD209945A3 - PROCESS FOR SEMICONDUCTORAL BIOMASS RECOVERY - Google Patents

Abstract

The invention relates to a process for growing microorganisms in order to obtain biomass at high productivity, to realize low specific substance uses and / or high utilization rates of the carbon substrate. The object of the invention is to develop a process which is more efficient than control the use of the source of energy and carbon by the microorganisms, to achieve the goal of high yields and low operating costs. The object is achieved according to the invention by controlling the exchange of fermentation medium in the semicontinuous Zellenzichting after the state of the microorganisms. The state of the microorganisms can be monitored by monitoring the proportion of growing cells, e.g. budding yeast cells, to the total population are determined from the microscopic image. The replacement of preferably half of the fermentation medium against a nutrient medium, which was preferably balanced for a doubling of the cell count and mass, takes place at the end of the growth phase.

Description

title

Method of growing microorganisms.

Field of application of the invention;

The invention relates to a method for the semicontinuous cultivation of microorganisms for biomass production. The invention is classified in the IPK C 12 IT.

Characteristic of the known technical solutions

From the patent literature a seinikontinuierliches feed process for the preparation of protein and yeast is i ⁿ known a ventilated Permenter, wherein after a period Λ tp a weight Δ g is harvested to yeast slurry and a quotient Δ g / Δ t "is chosen so large. that Δt ₂ > 0 (DE-OS 27 52 485 32), The yeast culture is grown in two mutually peeling phases. In phase I of duration Δ t.

is supplied to the reactor nutrient medium, which may contain carbohydrates, ammonium lactate and / or lactic acid. In phase II, no medium is supplied to the per- mentor. Cultivation is carried out until the exhaustion of carbon and energy sources and the metabolites and then the per-mentor a weight Δ g of Hefesusoension taken *

Part of this procedure is the high residence time of the yeast cells in the reactor (up to 30 hours) and the possibility of uptake of excess nutrient components by the microorganisms during this period "5 'This can lead to high specific material consumption and cooling costs of the process (Heinritz, B ., Dissertation A, Leipzig 1978).

The patent literature further discloses two-stage continuous processes which, in addition to the biomass production, aim at an increased use of the carbon and energy sources, eg "high utilization of the paraffins of the petroleum distillate in the course of its production" (DD-TO 105 825). ,

With a residence time of 10 hours and a gas oil distillate content of 10 Ma, % with a paraffin content of 38 Ma "%, a productivity of 2.6 g HTS / kg h and a specific paraffin consumption of 1.3 s / g HTS were achieved. After a residence time of the microorganisms in the two fermentation stages of the Srdöldestiilatkonvertierung of 10 hours, only one pour point of the diesel fuel was - 30 ⁰ C achieved.

Disadvantage of this process is the high residence time of the microorganisms in the two fermentation stages, which can lead to high specific substance consumption and thermal fertilization and to the storage of reserve substances, such as lipids or carbohydrates, in the cells.

Aim of the invention;

The aim of the invention is the reduction of the specific substance consumption, the increase of the biomass formation rates and / or high utilization levels of the nutrients, in particular a high utilization of the carbon substrate in the biomass orogenesis.

presentation; the essence of the invention;

The object of the invention is to develop a method which makes it possible on the way to control the use of the source of energy and carbon by the microorganisms, .das goal to achieve high yields and low operating costs.

The object is achieved by controlling the exchange of fermentation medium in semikontnuierlichen cell culture according to the state of the microorganisms

TO reached.

The solution according to the invention provides for the replacement of the fermentation medium at the end of the growth phase of the microorganisms, the end of the growth phase can reliably through. tracking the number of cells and / or determining the proportion of proliferating cells, z, B * of the proportion of budding cells in the total population from the microscopic image *

Since the duration of the growth phase in a fermentation system in semicontinuous Zellenzüchtimg under given fermentation conditions remains constant, one-time microscopic examinations on a technical scale are sufficient. The replacement of the Pensentationsmediuns is such that half or more than half, preferably half of the fermentation medium is discharged * Subsequently, nutrient medium is supplied with sufficient for one to three, preferably for a doubling of the cell count and mass amount of nutrient. The growth process is to be limited by the carbon and energy source, as this restricts the formation of reserve substances. A slight excess of oxygen and the other elements essential for microbial growth is to be recommended * In the fermentation of oxygen-free carbon substrates, great importance is attached to compliance to put excess oxygen,

As a result, high biomass yields, high protein contents of the cell substance and low cooling costs of the process can be achieved. This also applies to the microbial utilization of several carbon and energy sources at their optimal carbon and energy ratio,

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Embodiment ·

The invention is illustrated by the following examples:

example 1

The aim of semi-continuous petroleum distillate fermentation is to achieve high paraffin utilization rates and low pour points of the petroleum distillate after fermentation »yeasts of the species Lodderomyces elongisporus were cultured on petroleum distillate (ED) as the only carbon source semicontinuously in a 10 1 Rührferinentor, the fermentation conditions were:

Carbon supply (ED supply) 20 Ma,% n paraffin content in ED 22 Ma, %

Hazardous solution composition: 21.1 g (1 H) ₉ SO ₇ , 4.0 g KH PO ₄ per liter, per liter

1j3 g H ^ PO ^ 85% per liter 0.85 g MgSO ₄ . 7 H ₉ O per liter pH value: 4.2 (control with 10% NaOH) Temperature: 32 ° C Ventilation rate: 80 l / kg ~ h Fermentor content: 5 kg

At the beginning, 4 l of nutrient solution and 1.2 l of ED are filled into the reactor, ventilated, heated and inoculated with yeast suspension. The yeast population was grown intermittently until the pH and / or the dissolved oxygen concentration of the fermentation medium increased. At this point, 2.5 kg of fermentation medium were withdrawn from the reactor and then 2 liters of nutrient solution 0.6 l of ED were added to the fermentation medium remaining in the reactor.

The SD fermentation is performed until the proportion of budding cells in the population drops to approximately 30 % and / or the increase in the dissolved oxygen concentration in the fermentation medium.

Again, 2.5 kg of fermentation medium is drained from the reactor and the process is continued as described.

By applying the method described, the following process parameters were obtained: n-paraffin

^ _x 1-1 g / s

± 2.8g HTS / kg h

Petroleum distillate use 100 ml ED / h

-IO residual paraffin content of ED after fermentation 3> 5 Ma,% pour point of SD after fermentation - 46 ° C biomass concentration in the effluent 34 g HTS / kg mean residence time of yeast cells in the reactor 12 h paraffin utilization 86 %

Example 2

Yeasts of the species Lodderomyces elongisporus were bred on petroleum distillate (EI) as the sole source of carbon and energy semicontinuously in a 10 1 stirred fermentor. The fermentation conditions were:

Carbon Substrate Offering (ED Offering): 20 Ma, $ n Paraffin Content of ED: 12 Ma % Compound Composition: 10.6 g (HH ₂ ) ₂ S0 _d per liter 2.0 g KH ₂ PO ₁ 'per liter

0.7 g H-PO ^ '3552 per liter

0.4 g MgSO 4 .7 ^H 2 ° P ^{ro Lli; e; r} pH value: 4.2 (pH control with 10% UaOH) temperature 32 ° G aeration rate 50 l / kg h fermenter content 5 kg

At the beginning, 4 l of nutrient solution and 1.2 l of ED were introduced into the reactor, aerated, tempered and seeded with yeast suspension.

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The yeast cell population was grown intermittently until the pH and / or the dissolved oxygen concentration increased. A mass of 2.5 kg of the yeast suspension is removed from the reactor and then 2 liters of Hährlösung and 0.6 1 of ED are added to the remaining fermentation medium in the reactor.

The SD fermentation is performed until the fraction of budding yeast cells in the population drops to approximately 30 % and / or the increase in the dissolved oxygen concentration of the fermentation medium.

Again, half of the bulk content is removed from the reactor and the process continues as previously described.

By applying this solution according to the invention, the following process characteristics were achieved: n-paraffin

, 0 g / g HTS

_x g

χ 1.35 g HTS / kg h

Petroleum distillate use 100 ml ED / h

Residual paraffin content of the ED after fermentation 3.5 Ma,% pour point of the ED after fermentation - 46 ° C biomass concentration in the effluent 16 g HTS / kg h mean residence time of the microorganisms in the reactor 12h paraffin utilization rate ⁷ ^

75

Example 3

The goal of semi-continuous cell culture was high growth rates, low specific carbon substrate consumption, oxygen consumption and heat generation, and wasting of the carbon and energy source fed in. "

Yeasts of the species Lodderomyces elongisporus were cultivated on a paraffin mixture of the chain length Cq to C-> _n as sole carbon and energy source in a 10 1 stirred ferment or

The following fermentation conditions were chosen:

Paraffin supply per phase culture: 11.4 g paraffin / 2 h

Nutrient composition:

9.6 g (MH ₄ ) ₂ SO ₄ per liter

0.9 g K ₂ CO. Per liter

0.7 g H ₃ PO ₁ 85% per liter

0.4 g MgSOzT ₁ H ₂ O per liter pH 4.2 (pH control with 10 % ITaOH) temperature 32 ° C aeration rate 80 l / kg h fermenter content 4 kg

At the beginning, 4 liters of nutrient solution are filled into the reactor, heated, ventilated and inoculated with yeast suspension. The growth process is continued until the consumption of carbon and energy has been reduced to about 20 % by increasing the proportion of budding cells pH, the dissolved oxygen concentration of the fermentation medium, decrease in the carbon dioxide content in the air, increase in the oxygen content of the exhaust air and decrease in the formation of heat announced, led,

2 kg of Fermentorinhaltes γ / earth removed from the reactor. Thereafter, 2 liters of nutrient solution are added to the remaining fermentation medium in the reactor. The yeast population is cultured again until the carbon and energy source is consumed.

The sprouting state of the yeast cells serves to control the exchange of fermentation media for an equivalent weight of nutrient solution. The exchange takes place when the proportion of budding yeast cells in the population drops to approximately 20 %,

The phase cultures are limited by the concentration of the carbon and energy source (paraffin concentration). A slight excess of the other nutrient components v, a, the supply of phosphorus and oxygen supply in the air lead to low specific material consumption and heat generation

 By applying the method described, the following process codes were achieved:

x 5.3 g HTS / kg h

Paraffins X _v 1.08 g Parffin / g HTS Phosphorus

dC 9.3 mg phosphorus / g HTS

⁰ PX ^ 2.2 g 0 ₂ / g HTS x

Heat _{?> 5 kcal / g HTS} ( _{31) 4 kJ} / _{g HTS} )

^ 'ζ

Residence time of the yeast cells in the reactor 4 h Biomass concentration in the effluent 21.2 g HTS / kg

Example 4

The aim of the semi-continuous cell culture was high growth rates, low specific carbon substrate consumption, oxygen consumption and heat generation and full utilization of carbon and energy sources, yeasts of the species Lodderomyces elongisporus were on a paraffin mixture of chain length CLq to Cp ₀ and sucrose in the ratio 15 Ma *% to 85 Ma.% As carbon and energy sources in a 10 1 stirred fermentor cultivated.

The fermentation conditions were: Paraffin supply per phase culture: 0.91 g / 1.1 h sucrose supply per phase culture: 8.5 g / 1.1 h

Dissolution rate: 4.8 g (IH ₄ ) ₂ SO ₄ per liter 0.45 g K ₂ CO ₃ per liter 0.35 g H ₃ PO ₄ per liter 0.2 g MgSO 4. * 7 H ₂ O per liter pH 4.2 (pH-control with 10% JIaOH) temperature 32 ⁰ C.

Ventilation rate 40 l / kg h Permentorol content 5 kg

At the beginning, 5 liters of nutrient solution are filled into the perforator, ventilated, tempered, and inoculated with yeast suspension. When the proportion of sprossender cells decreases after passing through a maximum to ca, 20 % 2.5 kg of yeast suspension are removed from the reactor and then added 2.5 1 of nutrient solution in the permentor,

The cultivation of the yeast is up to the exhaustion of the carbon and energy sources, by increasing the proportion of sprouting cells to 20%, increasing the pH, the dissolved oxygen concentration of the fermentation medium, drop in carbon dioxide content of the exhaust air, decrease in heat production and increase in oxygen content announces the exhaust air, led, 2 kg of the fermentation medium are exchanged for an equivalent weight nutrient solution and the process described repeated arbitrary times, the exchange is controlled by the rung state.

In this way and the following process indicators were achieved:

Productivity 4.55 g HTS / kg h

Specific Substrate Consumption 1.74 g / g HTS Specific Phosphorus Consumption 7.5 mg / g HTS Specific Oxygen Consumption 1.02 g / g HTS Specific Vigree Product Ion 3.4 kcal / g HTS 5 Residence Time of Microorganisms in Reactor 2.2 h Biomass concentration in effluent 10 g / kg

Claims (3)

invention claim A process for semi-continuous biomass recovery on one or more carbon and energy sources, characterized in that the nutrient medium containing nutrients for one to three, preferably for a doubling of the cell count and mass, is added at time intervals equal to the duration of the Growth phase of the synchronized microorganism population, 2 * method according to item 1, characterized in that at the time of supply of Uährmediums half or more than half, preferably half of the perforation medium is discharged and an equivalent amount of Mhrmedium is added » 3 »Procedure by Points. 1 and 2, characterized in that the microbial growth is limited by the carbon and energy source and a low excess of all other essential for growth elements is observed. For this 1 page drawings