PRODUCTION OF YEAST FROM FOOD INDUSTRY WASTE

АННОТАЦИЯ

В данной статье рассмотрены оптимальные условия получения дрожжей из отходов предприятий шейкерного производства. Для этого исследования были использованы Тефф и Стелла. Полученные образцы объемом 1 мл растворяли в дистиллированной воде и очищали. Были проведены полученные серийные разведения. Образцы хранили при 25°С в течение 48 часов и при 40°С для дальнейших исследований. Ацетатно-агаровая среда. Для культивирования использовали такие соединения, как глюкоза, тригидрат ацетата натрия и хлорид калия. Также контролировали pH этой технологической среды.

ABSTRACT

This article examines the optimal conditions for obtaining yeast from the waste of shaker production enterprises. Teff and Stella were used for this study. The obtained 1 ml samples were dissolved in distilled water and purified. The resulting serial dilutions were carried out. Samples were stored at 25 °C for 48 h and at 40 °C for further studies. Acetate agar medium. Compounds such as glucose, sodium acetate trihydrate, and potassium chloride were used for cultivation. The pH of this process media was also controlled.

Ключевые слова: калий, натрий, магний, экстракты, ламинар, углеводы.

Keywords: potassium, sodium, magnesium, extracts, laminar, carbohydrates.

Introduction

Today, as living standards improve in most countries, consumer demand for healthy, nutritious and safe food is constantly increasing. Yeasts, which are safe and nutritious, are now a natural, high-quality product that can meet various food requirements[1,2]. Yeast extracts are usually obtained from yeast wastes (e.g., baker's yeast, brewer's yeast, Candida utilis, Candida tropicalis, and Kluyveromyces marxianu) [3] in various ways[4]. Yeast extract is recognized as a generally safe product by most food safety certification bodies worldwide [5]. Water is an important yeast cell component, making up about 75%. The dry matter has the following composition: proteins 40-60%, carbohydrates 25-35%, fats (lipids) 4-7%, minerals 6-9%. Minerals include phosphates, potassium, calcium, magnesium, zinc, iron, manganese and copper[6]. In addition, yeast cells contain many vitamins, including nicotinic acid 29-90 mg; thiamine (B₁) 7-16 mg per 100 g of dry yeast; riboflavin 3-7 mg; pantothenic acid 3-25 mg; folic acid 4-15 mg; pyridoxine 4-10 mg; biotype 0.1^-1 mg[7].

Experimental part

Materials and devices

Laminar air flow cabinet

Spectrophotometer, incubator and shaking incubator, vortex machine, autoclave machine, glassware, laboratory distillation apparatus-fractional distillation apparatus, microscope, petri dishes with pH meter, slopes, micropipettes, Bunsen burner, hot plate, clamps, electric balance, microburette, etc.

Separation of Yeast Strains from Teff and Stella.

Teff and Tella yeast samples were found in waste samples from a sugar factory. 1 ml of the samples was taken and dissolved in 9 ml of purified, distilled water and mixed well. After serial dilutions (10^-1 -10^-6) are performed, at each subsequent step of the stage, increasing numbers of yeast or tella samples are kept in diluted aqueous suspensions.

It was studied how many mg/l concentrations were present in this obtained medium: yeast extract 3, malt extract 3, peptone 5, glucose 10 and agar 20. Chloramphenicol (0.1 gm/l) was added to each of these samples as an inhibitor of bacterial growth. ) added. Samples were stored at 25°C for 48 hours and stored at 40°C for further studies.

Acetate agar medium.

2.5 grams of yeast extract, 1.0 grams of glucose, 8.2 grams of sodium acetate trihydrate, 1.8 grams of potassium chloride, and 15 grams of agar were dissolved in distilled water in a one liter container. The vessel was slightly heated and after 12 hours it was poured into containers. The obtained samples were incubated for 3 weeks at a temperature of 25 ⁰C.

Observation of yeast spores.

To observe the obtained samples, the spores on the wetted glass plates were stained, and after a certain time, when the glass plates were heated weakly for 30-60 seconds, the samples turned green with 5% water. Glass plates were heated for evaporation 3-4 times. The slides were then stained with 0.5% safranin red for approximately 30 seconds. The number of yeast cells in these samples was observed at (400×) and (1000×) magnification.

Preparation and physical and biochemical properties of molasses

The samples were taken from the waste of a sugar factory based on sugar cane. From these samples, for each experiment, molasses was diluted 1:3 using distilled water and the molasses was boiled and cooled to precipitate the insoluble materials.

The substrate was repeatedly centrifuged at high speed at 5000×g for 10 min to extract soluble materials from this sample. After that, the pH value of the soluble supernatant was adjusted to the appropriate value with HCl and NaOH. This process was carried out in an autoclave at 121 °C for 15 min.

The obtained samples are 20 ml of distilled water, 70 rpm for 15 minutes. Prior to in situ observations, yeast were grown in YPD (2% glucose, 2% peptone, and 1% yeast extract). About 10 g (wet) of rehydrated yeast cells were poured into two 250 mL Erlenmeyer flasks of 150 mL each. The flasks were incubated on a shaker at 32 °C, 120 rpm for 74 h. Subsequently, centrifugation (5000×g , 15 min) was performed for in situ experiments. The process was carried out at a pH value of 4.5.

Results and Discussion

Determination of dry weight of molasses. The dry weight of the molasses sample was placed in a crucible containing the mass of the molasses sample, about 5 grams, and the crucible with the molasses sample was kept in an oven at a temperature of 105 ⁰C for 2 hours. The crucible containing the molasses sample was cooled in a desiccator and weighed. The process of heating, cooling and weighing was repeated until a constant dry weight was obtained. The dry weight percentage of the molasses sample was determined using the following formula.

where:

W₁- Weight in grams of crucible with molasses sample before drying

W₂- weight in grams of the crucible with the dried sample

W- the weight of the empty crucible in grams.

Preparation of nutrient medium for yeast strains

Providing a nutrient medium for yeasts is one of the most important factors in obtaining yeasts, and for this reason, the following several methods can be proposed and the most optimal of them has been selected:

1). Agar nutrient medium is a common microbiological growth medium. Nutrient agar typically contains 0.5% peptone, 0.3% beef extract/yeast extract, 1.5% agar, 0.5% NaCl, 97.2% distilled water.

2). Yeast Extract Peptone Dextrose Medium (Agar and Broth)

For the growth of yeast in peptone and acid media, complete nutrient quantities contain 1% yeast extract, 2% peptone, 2% glucose or dextrose and distilled water, and can be used as a solid medium with the addition of 2% agar.

3). Starch and agar media

Starch agar is used to monitor the specific growth of microorganisms and the activity of starch hydrolysis. It contains 0.3% beef extract, 0.5% peptone, 0.2% starch and 1.5% agar as the main ingredients.

4). Carboxymethylcellulose and agar media

It is used to test the cellulosic activity of bacteria (or fungi) in this medium. Contains 1.5% peptone, 0.3% K₂HPO₄, 0.045% MgSO₄, 0.375% (NH₄)₂SO₄, gelatin: 0.3% and 1.5% agar.

Conclusion

Optimum conditions for obtaining yeasts such as Teff and Tella based on sugar production waste have been studied. A methodology for the isolation of Teff and Tella strains was developed, in which the method of agar muhi and serial dilution was used, and the optimal temperature in this process was 25 ⁰C and 40 °C, and the duration of time was determined to be 48 hours.

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