DE2752452A1 - METHOD OF BREEDING MICRO-ORGANISMS - Google Patents

Description

Schwedt, November 14th, 1977

Applicant: VEB Petrolchemisches Kombinat Schwedt, 133 Schwedt / Oder

"Process for the cultivation of microorganisms"

IPK: C 12 b-1/20

Field of application of the invention:

The invention relates to a method for growing microorganisms on straight-chain hydrocarbons, especially the aerobic cultivation of microorganisms, whereby the microorganisms are bred to obtain single-cell protein for feeding purposes or for human consumption will.

809825/0666 ~ ² ~

The invention belongs to the field of technical microbiology and can be used in systems in which from Hydrocarbons Proteins produced «earth.

Characteristics of known technical solutions;

In the case of industrially used processes, the questions of the cost-effectiveness of the process play a role alongside the quality of the Products play a decisive role, with the following main objectives being pursued:

- High utilization rate of the hydrocarbon source used for cell substance synthesis

- High utilization rate of the introduced oxygen for the cell substance synthesis, since for the dispersion of the Oxygen or the oxygen-containing gas expended energy must be and a Ve rat me η of the oxygen aufterdem leads to carbon losses.

- If the biomass is to be processed into putter or food, a high crude protein content and a A favorable rate of use of the nitrogen consumed for digestible proteins is sought, so that, for example, the nucleic acid nitrogen content is kept as low as possible.

- Achieving high biomass concentrations in the Permentor to keep processing costs low.

In order to achieve these objectives, different Ways suggested.

- 3 8 0 982 5/066 6

There were fermentors with high aeration intensity and high oxygen transfer rate, e.g. submersible jet fermentors (DL-WP 111.144).

To improve the exchange of substances for oxygen from the air into the fermentation medium, it has been proposed to use surface-active substances (DT-OS 1.442.296). A variety of different microorganisms have been studied and proposed according to their different specific performance and quality indicators depending on the main objective of the process.

And finally, various substances were used as growth and quality stimulators are proposed (DT-OS 1.470.490, DT-OS 1.470.507, DL-WP 50.543 and DT-OS 2.043.206). Use of a carbon source with a preferred carbon number from 10-14 for fermentation in a concentration of η-paraffins in the phase of logarithmic growth of the Yeast cells between 0.08 and 0.10% by weight of the culture suspension (DL-AP 113.927).

While all of these proposed procedures bring advances but from the theoretical balances it can be seen that the microorganisms used still have considerable reserves in terms of the use of the consumed carbon, oxygen and also of nitrogen in favor of the desired pure proteins.

Aim of the invention:

The invention is based on the aim of improving the use of the reserves of the microorganisms to achieve the economic viability of the process for the cultivation of microorganisms on straight-chain hydrocarbons «

809825/0666 - 4 -

Statement of the essence of the invention;

From the aim of the invention, the technical problem is derived from designing the process conditions so that an optimal .Maturity level of the microorganisms can be reached.

Features of the invention:

Surprisingly, it was found that the composition of the n-paraffins on the characteristics of the hydrocarbons used off raw materials themselves in conjunction with defined Process conditions have a considerable influence on the degree of maturity the microorganism cells and also affect the quality of the products.

When studying the relevant technical and patent literature it can be seen that for the cultivation of microorganisms the starting products of the carbon source are used as they occur in the baffle industry.

On the other hand, the n-paraffin-containing hydrocarbon fractions used in such a way that they meet the intended use after microbiological dewaxing. Connections between the maturation of microorganism cells, the quality of the end product protein with regard to the feed fractions and the fermentation conditions not known so far.

By systematic research it has been found that instead of the commonly used insert fractions of boiling range 200 - defined 380 ⁰ C n-paraffin sections or n-paraffin holding strength hydrocarbon mixtures of a higher boiling employed and in each case selected the conditions of the best breeding outcome for the cuts significantly better

809825/0666

Results in improving the specific oxygen, carbon and nitrogen consumption in favor of pure protein be achieved.

Particularly high biomass concentrations are reached when the n-paraffin sections used or n-paraffin holding strength mixtures a to 60-120 ⁰ C, in particular 80 - have higher 100 ⁰ C Initial boiling point, ie, it is a higher number of C atoms of the n-paraffins with a simultaneous narrowing of the C number range is required.

This value is achieved when at least 70 % of the straight-chain hydrocarbons used have a C number greater than 15.

Another essential feature of the invention is that the residence time of the fermentation mixture to microorganisms / carbon source / aqueous The nutrient medium in the Permentor must not fall below a defined limit value. This limit is about 1-2 hours higher than the natural growth rate of the microorganisms under the conditions of the hydrocarbon fermentation would be possible and with the previous processes is applied.

In the previous processes using the normal mixtures, the residence time was usually in the vicinity of the Shortest possible dwell time is set in order to cope with the breathing rate of the known to be higher with longer dwell times to avoid the carbon source used and the oxygen introduced.

However, these short residence times have the disadvantage that the cell can not fully mature. The differences in the overall biological reaction sequence of cell substance synthesis when using the solution according to the invention are of an extremely complex nature.

809825/0666 " ⁶ "

Overall, the advantages resulting from this difference stem from the fact that cell substance synthesis takes longer uniform n-paraffin chains less energy and metabolic products are released from the cell and that with the higher optimal residence time found, better ripening the cell, e.g. in cells with a higher degree of maturity, the ratio of cytoplasm to the cell nucleus is cheaper, so that the indigestible nitrogen compounds bound in the cell nucleus are relatively reduced.

Obviously there is less oxygen, carbon and nitrogen for metabolites and indigestible nitrogen compounds consumed, with the known higher breathing rate due to the entering with the higher dwell time Benefits are more than or at least compensated for.

The invention thus relates essentially to a new method in which the achievement of the optimal degree of maturity of the MO line for protein production among the cheapest economic Conditions is made possible · Furthermore, there is a direct advantage when using higher Sections in such a way that natural evaporation losses of hydrocarbons occur during aerobic fermentation be reduced by about half.

If the method according to the invention in connection with the Product processing of the mineral oil industry or a petroleum processing company or petrochemical combines can continue to have a number of advantages in terms of economic Use of the constituents of heavy petroleum fractions for protein production occur as well as in the form that the lighter components previously used an economically or economically more favorable use can be.

809825/0666

Execution example

In the following examples, two process variants are given using Candida guilliermondii as the production culture.

In the following summary tables are the advantages shown compared to a conventional process example. As the indicators show, there are significant advantages in of industrial use.

The use of Candida guilliermondii is to be regarded as an example, but not as a limitation. The fundamental tendencies, as can also be proven thermodynamically, are valid for all microorganisms, which can mainly utilize η-paraffins for cell substance synthesis.

example 1

In a 500 1 stirred tank test fermentor that is used with all Equipped with the necessary facilities and measuring technology for the aerobic continuous cultivation of MO is, Candida guilliermondii was grown on purified n-paraffins under the following conditions:

Initial boiling point of n-paraffin fraction 300 ⁰ C final boiling point of the n-paraffin fraction 380 ⁰ C.

Average C number of the η paraffins C ^ g

Fermentation mixture in the permentor 200 kg

Residence time of the Permentatbnsgemisches 8 h

Feed of n-paraffins 1.05 kg / h

Temperature 34 ⁰ C

pH 4.2

809825/0666 - ⁸ -

The concentration of nutrients and trace elements in the fermentation mixture was maintained by continuous dosing with an appropriate nutrient solution:

NH ₄ " 100 - 155 mg / 1 Mg ⁺ * 20-30 mg / 1 ^P0 C 200 - 300 mg / 1 Zn ⁺⁺ 3-6 mg / 1 so ₄ 50 - 100 mg / 1 Mn ⁺⁺ 3-6 mg / 1 K ⁺ 60 - 90 mg / 1 Cu ⁺ 0.02 mg / 1 Ca ⁺⁺ 10 - 15 mg / 1 Pe ⁺⁺ 5-7 mg / 1

Specific ventilation rate: 70 1 air / kg fermentation mixture

Specific service entry

through the agitator (net): 10 watts / kg permentation mixture

The experiment was carried out over about 10 days, with the Biomass was removed, cleaned and dried for analysis and the corresponding tests. The following results were obtained (column 2). Table 1 shows the results of a conventional one for comparison Fermentation with the n-paraffin mixture from the boiling area

200 - 380 ⁰ C and the usual residence time 0
85 2 , 5
, 01 from 4 hours given. 40
1 1 dimension Biomass concentration
Biomass production 17,
O, g / kg
kg / h

809825/0666 - 9 -

275245?

M>

Specific oxygen 2.5 2.1 kg 0 ₂ / kg HTS consumption Specific n-paraffin 1.23 1.04 kg nP / kg HTS consumption 58.0 64.0 ⁰ yo Crude protein content 47.0 56.0 % Pure protein

Percentage of nitrogen consumed in the
Pure protein

81.0 87.5

Example 2

In the test station according to Example 1, Candida guilliermondii was produced under similar conditions as in Example 1 continuously bred as follows:

Aeration rate: 70 1 air / kg fermentation mixture

Specific power input by the stirrer: 8 watts / kg fermentation mixture. The concentration of nutrient and trace salts was maintained as in Example 1.
Temperature:
PH value:

33 ⁰ C

Dwell time:

It became a gas oil

section of the settlement:

'23 809825/0666

295 - 370 ⁰ C used from a petroleum containing 20.1 weight ^ n-paraffins with an average C number of C ₁₈ , in the range C ^ c-

- 10 -

The gas oil concentration
in the permentation medium
fraud:

26.5 *

The experiment was run for 8 days.

After the fermentation, the unused gas oil was separated off by means of a continuously operating te maker. The yeast suspension, largely freed from the gas oil, was dried. It was then extracted in discontinuous batches with an organic solvent mixture (gasoline / isopropanol), dried and analyzed accordingly. The following results were obtained (column S). Column 1 shows the results of an analogous experiment for a usual method with a gas oil section of the boiling range 230 for comparison - indicated 350 ⁰ C. The residence time in this experiment was 4 hours. The gas oil concentration 14 f> at 19.8% η-paraffins in the gas oil cut · The mean C number of the η-paraffins contained in the gas oil cut was in the range Cq - C ₂₂

π

1 2 dimension Biomass concentration 14.2 28.1 g / kg Biomass production 0.71 0.804 kg / h Specific sour s t off consumption 2.4 2, t2 kS σ ₂ / kg HTS Specific n-paraffin consumption 1.13 1.00 kg nP / kg HTS Eoh protein content 63.0 67.0 Hein protein content 51.7 57.5 Proportion of consumed Nitrogen in leg protein 82.0 86.0 *

809825/0 666

- 11 -

Claims (1)

-u- Invention at s pruchi Method characterized for the cultivation of microorganisms on straight-chain hydrocarbons for the production of single cell protein by an improved maturation of the microorganism cells in that the η-paraffin used or η-paraffinic Einsabzfraktion compared to the previously used fractions 200-380 ⁰ C a to 60-120 ⁰ comprises 100 ⁰ C, higher boiling point and thus a higher average C-number of η-paraffins of at least 17, wherein the carbon number range is narrowed so that at least 70 Io of the straight chain hydrocarbons used larger a C number - C, in particular 80 than 15 and the residence time of the fermentation mixture, consisting of microorganisms, carbon source, aqueous nutrient medium, in the permentor is at least 5 hours. 809825/0666