Name: the cultivation, growth, and viability of lactic acid bacteria: a quality control perspective
Uploaded: 2022-06-16T12:40:00
Description: Watch this Scientific Journal Video about The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective at JoVE.com

This publication was made possible by grant number NC.X-267-5-12-170-1 from the National Institute of Food and Agriculture (NIFA) and in part by NIZO Food Research BV, The Netherlands, Jarrow Formulas, USA, and the Department of Family and Consumer Sciences and the Agriculture Research Station at North Carolina Agriculture and Technical State University (Greensboro, NC, USA 27411). This work was also supported, in part, by 1890 Capacity Building Program grant no. (2020-38821-31113/project accession no. 021765). This work was also partially supported by the Bulgarian Ministry of Education and Science under the National Research Programme &#8216;Healthy Foods for a Strong Bio-Economy and Quality of Life&#8217; approved by DCM # 577 / 17.08.2018.

1. General materials and methods
<ol>
	<li>Source of Lactobacillus delbrueckii subsp. bulgaricus
	<ol>
		<li>Obtain L. bulgaricus strains from reliable sources. 
		NOTE: In this study, a total of five (5) L. bulgaricus strains were used in the quality control study (Table 1). Two strains of freeze-dried L. bulgaricus for the industrial production of fermented milk products were provided by Dr. Albert Krastanov, Department of Biotechnolo...

<ol>
	<li>Karakas-Sen, A., Karakas, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation,+identification+and+technological+properties+of+lactic+acid+bacteria+from+raw+cow+milk.">Isolation, identification and technological properties of lactic acid bacteria from raw cow milk.</a> Bioscience Journal. 34 (2), 385-399 (2018).</li><li>Martin, R., Langella, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Emerging+health+concepts+in+the+probiotics+field:+Streamlining+the+definitions.">Emerging health concepts in the probiotics field: Streamlining the definitions.</a> Frontiers in Microbiology. 10, 1047 (2019).</li><li>Sadishkumar, V., Jeevaratnam, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+probiotic+evaluation+of+potential+antioxidant+lactic+acid+bacteria+isolated+from+idli+batter+fermented+with+Piper+betle+leaves.">In vitro probiotic evaluation of potential antioxidant lactic acid bacteria isolated from idli batter fermented with Piper betle leaves.</a> International Journal of Food Science &amp; Technology. 52 (2), 329-340 (2017).</li><li>Ayivi, R. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lactic+acid+bacteria:+Food+safety+and+human+health+applications.">Lactic acid bacteria: Food safety and human health applications.</a> Dairy. 1 (3), 202-232 (2020).</li><li>Quinto, E. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Probiotic+lactic+acid+bacteria:+A+review.">Probiotic lactic acid bacteria: A review.</a> Food and Nutrition Sciences. 5 (18), 1765-1775 (2014).</li><li>Hayek, S. A., Gyawali, R., Aljaloud, S. O., Krastanov, A., Ibrahim, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cultivation+media+for+lactic+acid+bacteria+used+in+dairy+products.">Cultivation media for lactic acid bacteria used in dairy products.</a> Journal of Dairy Research. 86 (4), 490-502 (2019).</li><li>Bintsis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lactic+acid+bacteria+as+starter+cultures:+An+update+in+their+metabolism+and+genetics.">Lactic acid bacteria as starter cultures: An update in their metabolism and genetics.</a> Aims Microbiology. 4, 665-684 (2018).</li><li>Shao, Y., Gao, S., Guo, H., Zhang, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+culture+conditions+and+preconditioning+on+survival+of+Lactobacillus+delbrueckii+subspecies+bulgaricus+ND02+during+lyophilization.">Influence of culture conditions and preconditioning on survival of Lactobacillus delbrueckii subspecies bulgaricus ND02 during lyophilization.</a> Journal of Dairy Science. 97 (3), 1270-1280 (2014).</li><li>Aryana, K. J., Olson, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+100-year+review:+Yogurt+and+other+cultured+dairy+products.">A 100-year review: Yogurt and other cultured dairy products.</a> Journal of Dairy Science. 100 (12), 9987-10013 (2017).</li><li>Kandil, S., El Soda, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+freezing+and+freeze-drying+on+intracellular+enzymatic+activity+and+autolytic+properties+of+some+lactic+acid+bacterial+strains.">Influence of freezing and freeze-drying on intracellular enzymatic activity and autolytic properties of some lactic acid bacterial strains.</a> Advances in Microbiology. 5 (6), 371-382 (2015).</li><li>Malairuang, K., Krajang, M., Sukna, J., Rattanapradit, K., Chamsart, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+cell+density+cultivation+of+Saccharomyces+cerevisiae+with+intensive+multiple+sequential+batches+together+with+a+novel+technique+of+fed-batch+at+cell+level+(FBC).">High cell density cultivation of Saccharomyces cerevisiae with intensive multiple sequential batches together with a novel technique of fed-batch at cell level (FBC).</a> Processes. 8 (10), 1321 (2020).</li><li>Jeanson, S., Floury, J., Gagnaire, V., Lortal, S., Thierry, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bacterial+colonies+in+solid+media+and+foods:+A+review+on+their+growth+and+interactions+with+the+micro-environment.">Bacterial colonies in solid media and foods: A review on their growth and interactions with the micro-environment.</a> Frontiers in Microbiology. 6, 1284 (2015).</li><li>Oyeniran, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+modified+reinforced+clostridial+medium+for+the+isolation+and+enumeration+of+Lactobacillus+delbrueckii+ssp.+bulgaricus+in+a+mixed+culture.">A modified reinforced clostridial medium for the isolation and enumeration of Lactobacillus delbrueckii ssp. bulgaricus in a mixed culture.</a> Journal of Dairy Science. 103, 5030-5042 (2020).</li><li>Iguchi, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+repeated+subculturing+and+prolonged+storage+at+room+temperature+of+Enterohemorrhagic+Escherichia+coli+O157:+H7+on+pulsed-field+gel+electrophoresis+profiles.">Effects of repeated subculturing and prolonged storage at room temperature of Enterohemorrhagic Escherichia coli O157: H7 on pulsed-field gel electrophoresis profiles.</a> Journal of Clinical Microbiology. 40 (8), 3079-3081 (2002).</li><li>Hayek, S. A., Ibrahim, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+limitations+and+challenges+with+lactic+acid+bacteria:+a+review.">Current limitations and challenges with lactic acid bacteria: a review.</a> Food and Nutrition Sciences. 4 (11), 73-87 (2013).</li><li>Ahmed, S. A., Ibrahim, S. A., Kim, C., Shahbazi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Significance+of+bile+salt+tolerant+Lactobacillus+reuteri.">Significance of bile salt tolerant Lactobacillus reuteri.</a> Proceedings of the 2007 National Conference on Environmental Science and Technology. , 17-23 (2009).</li><li>Gyawali, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+study+of+extraction+techniques+for+maximum+recovery+of+&#946;-galactosidase+from+the+yogurt+bacterium+Lactobacillus+delbrueckii+ssp.+bulgaricus.">A comparative study of extraction techniques for maximum recovery of &#946;-galactosidase from the yogurt bacterium Lactobacillus delbrueckii ssp. bulgaricus.</a> Journal of Dairy Research. 87 (1), 123-126 (2020).</li><li>Nwamaioha, N. O., Ibrahim, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+selective+medium+for+the+enumeration+and+differentiation+of+Lactobacillus+delbrueckii+ssp.+bulgaricus.">A selective medium for the enumeration and differentiation of Lactobacillus delbrueckii ssp. bulgaricus.</a> Journal of Dairy Science. 101 (6), 4953-4961 (2018).</li></ol>

The results of all strains evaluated with the quality control protocol and without the use of the protocol were the same, and as such, results linked to only strains (S9, and LB6) were presented. The activated LAB strains had superior cell growth that was characterized by a high intensity of cell biomass, therefore, causing a turbid appearance of the MRS fermentative broth in the test tube11. The observed cell growth after culture activation was evident between 12 h and 16 h at an anaerobic fermen...

Lactic acid bacteria (LAB) are a group of uniquely diverse bacteria that have industrial potential. Strains belonging to Lactobacillus delbreuckii subsp. bulgaricus and Streptococcus thermophilus are mostly used as dairy starter cultures for fermented dairy food products such as yogurt1. Selected LAB strains are also classified as probiotics as they confer health benefits to humans when dosages are adequately administered2. Lactic acid bacteria are also gram-positive, non-spore-forming, non-respiring but aerotolerant microorganisms that are generally characterized by the production of lactic acid as a key fermentation product. LAB also synthesizes essential metabolites, for example, organic acids, bacteriocins, and other antimicrobial compounds3 that can inhibit a broad spectrum of foodborne pathogens4. Lactic acid, a major end product of carbohydrate catabolism and a by-product of LAB fermentation, is an organic metabolite that possesses antimicrobial properties and is potentially useful for food biopreservation applications3,5,6. Furthermore, the organic acids produced by LAB impart the flavor, texture, and aroma of foods, thus consequently enhancing their overall organoleptic properties5,6. The distinct nutritional requirements of LAB coupled with their ubiquitous nature, ultimately enable the bacteria to easily thrive in different environments such as dairy-based foods, fermented foods, vegetables as well as in the human gut7.
There is a growing demand for starter cultures from LAB for yogurt production and many diverse dairy applications8,9, hence critical attention and established scientific techniques should be adhered to, in LAB strains cultivation, as well as in the activation of both lyophilized and isolated strains as this activity is vital for enhanced fermentation performance. The Food Microbiology and Biotechnology laboratory, therefore, actively engages in suitable technology development geared toward the activation, superior growth, and fermentation characteristic of LAB strains isolated from fermented dairy products as well as from industrial starter cultures employed for yogurt production. Furthermore, it is noteworthy that LAB culture strains industrially produced undergo preservative activities such as freeze-drying and frozen storage, causing cell stress and injury, as a result of the cold shock process they are subjected to10. In limiting, the viability challenges and improving the functionality of LAB strains obtained from either isolated food products or freeze-dried products, it is important to properly activate these cultures as a form of quality control to enhance their fermentative characteristic8. In this study, the objective was to develop an in-house quality control protocol for the activation and growth of L. delbrueckii subsp. bulgaricus culture strains that ultimately promoted viable LAB growth, as well as enhanced the fermentation performance and the metabolic functionality of LAB strains. This protocol could ultimately be adapted (using optimal growth media and appropriate culturing conditions) for the cultivation of other LAB strains for fermentation research, as well as for industrial purposes or bioprocessing operations. This LAB activation and quality control protocol will therefore ensure superior viable dairy starter cultures are obtained and potentially functional for diverse applications in the global dairy and food industry.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Aniline Blue</td>
			<td>Thermo Scientific</td>
			<td>R21526</td>
			<td>25 g</td>
		</tr>
		<tr>
			<td>Beef extract</td>
			<td>Research Products International</td>
			<td>50-197-7509</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Yeast extract</td>
			<td>Fisher Scientific</td>
			<td>BP1422-500</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Calcium Chloride dihydrate</td>
			<td>Fisher Scientific</td>
			<td>C79-500</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Dextrose Anhydrous</td>
			<td>Fisher Scientific</td>
			<td>BP350500</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>D-Fructose</td>
			<td>ACROS Organics</td>
			<td>AC161355000</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Difco agar powder</td>
			<td>Difco</td>
			<td>DF0812-07-1</td>
			<td>2 kg</td>
		</tr>
		<tr>
			<td>TPY agar</td>
			<td>Difco</td>
			<td>211921</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Eppendorf microcentrifuge tube (Snap-Cap Microcentrifuge Safe-Lock)</td>
			<td>Fisher Scientific</td>
			<td>05-402-12</td>
			<td>2 mL</td>
		</tr>
		<tr>
			<td>Glycerol</td>
			<td>Thermo Scientific</td>
			<td>PI17904</td>
			<td>500 mL</td>
		</tr>
		<tr>
			<td>Infrared CO2 Incubator</td>
			<td>Forma Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus delbrueckii subsp. bulgaricus</td>
			<td>American Type Culture Collection (ATCC)</td>
			<td>ATCC 11842</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus delbrueckii subsp. bulgaricus</td>
			<td>Bulgaria</td>
			<td>S9</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus delbrueckii subsp. bulgaricus</td>
			<td>Bulgaria</td>
			<td>LB6</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus delbrueckii subsp. bulgaricus</td>
			<td>Food Microbiology and Biotechnology Laboratory (NCATSU)</td>
			<td>DAW</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus delbrueckii subsp. bulgaricus</td>
			<td>Food Microbiology and Biotechnology Laboratory (NCATSU)</td>
			<td>E22</td>
			<td></td>
		</tr>
		<tr>
			<td>Lactobacillus reuteri</td>
			<td>Biogai, Raleigh / Food Microbiology and Biotechnology Laboratory (NCATSU)</td>
			<td>RD2</td>
			<td></td>
		</tr>
		<tr>
			<td>L-Cysteine hydrochloride monohydrate</td>
			<td>Sigma-Aldrich</td>
			<td>C6852-25G</td>
			<td>25 g</td>
		</tr>
		<tr>
			<td>Maltose monohydrate</td>
			<td>Fisher Scientific</td>
			<td>M75-100</td>
			<td>100 g</td>
		</tr>
		<tr>
			<td>MRS broth</td>
			<td>Neogen</td>
			<td>50-201-5691</td>
			<td>5 kg</td>
		</tr>
		<tr>
			<td>Peptone No. 3</td>
			<td>Hach</td>
			<td>50-199-6719</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Potassium phosphate dibasic (K2HPO4)</td>
			<td>Research Products International</td>
			<td>50-712-761</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Sodium acetate trihydrate</td>
			<td>Fisher Scientific</td>
			<td>S220-1</td>
			<td>1 kg</td>
		</tr>
		<tr>
			<td>Sodium chloride</td>
			<td>Fisher Scientific</td>
			<td>BP358-1</td>
			<td>1 kg</td>
		</tr>
		<tr>
			<td>Sodium pyruvate</td>
			<td>Fisher Scientific</td>
			<td>BP356-100</td>
			<td>100 g</td>
		</tr>
		<tr>
			<td>Test Tubes with Rubber-Lined Screw Caps</td>
			<td>Fisher Scientific</td>
			<td>FB70125150</td>
			<td>25 x 150 mm</td>
		</tr>
		<tr>
			<td>Tween 80</td>
			<td>Fisher Scientific</td>
			<td>T164-500</td>
			<td>500 mL</td>
		</tr>
		<tr>
			<td>Ultra low freezer</td>
			<td>So-Low</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Uracil</td>
			<td>ACROS Organics</td>
			<td>AC157301000</td>
			<td>100 g</td>
		</tr>
		<tr>
			<td>UV- visible spectrophotometer</td>
			<td>Thermo Fisher Scientific</td>
			<td>Evolution 201</td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex Genie 2</td>
			<td>Fisher Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast extract</td>
			<td>Fisher Scientific</td>
			<td>BP1422-500</td>
			<td>500 g</td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Fisher Scientific</td>
			<td>T08204K7</td>
			<td>4 L</td>
		</tr>
		<tr>
			<td>Hydrochloric Acid (6N (Certified), Fisher Chemical)</td>
			<td>Fisher Scientific</td>
			<td>&#160;SA56-500</td>
			<td>500 mL</td>
		</tr>
	</tbody>
</table>

the cultivation, growth, and viability of lactic acid bacteria: a quality control perspective

Lactic acid bacteria (LAB) are essential dairy starter cultures that are significantly employed for the manufacture of fermented dairy products such as yogurt and cheese. LAB predominantly produce lactic acid as a major end product of fermentation, and they synthesize important metabolites that impart the organoleptic characteristics of fermented food products. LAB are fastidious bacteria that thrive in many environments when adequate nutritional requirements are fulfilled. The demand for superior LAB dairy starter cultures for fermentation applications in the food and dairy industry, has resulted in the need to provide viable and active cultures for all bioprocessing operations. The development of a standard protocol for ensuring the viability and enhanced functionality of LAB cultures in the laboratory as well as dairy processing environments is thus very critical. In addressing concerns linked to resuscitating weak, stressed, and injured LAB culture cells, a protocol that vividly outlines salient steps to recover, enhance cell regeneration, and improve metabolic functionality of LAB strains is of the utmost importance. The maintenance of culture purity, functionality, and viability for LAB starter cultures is likewise critical. Therefore, adherence to a unique protocol guideline will result in the promotion of fermentation performance for many LAB strains dedicated to fermentation and biotechnology processes. As a result, the Food Microbiology and Biotechnology Laboratory at North Carolina Agriculture and Technical State University has developed a standard protocol for the activation and quality control of selected LAB strains that has resulted in highly functional and viable LAB culture strains employed for fermentation research. The adaptation and recommendation of a protocol such as this for use in the dairy and food industry&#160;will help to ensure LAB viability and functionality for many applications.

Cell growth of the evaluated LAB strains cultivated with the quality control protocol was significantly different (P &#60; 0.05) than the strains cultivated without this standard protocol. The QC protocol for both L. bulgaricus and L. reuteri employed a multi-subculturing approach (subculturing three times before streaking on agar plates), whereas the control procedure had subculturing done only once with all other conditions kept constant. The colony growth was also higher and well defined on the growt...

Watch this Scientific Journal Video about The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective at JoVE.com

The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective

The quality control assessment of lactic acid bacteria (LAB) cultures has been confirmed as an effective way to enhance the viability and functionality of LAB strains for fermentation procedures. To buttress this assertion, we developed a protocol that elucidates how LAB cultures are activated and cultivated for fermentation and bioprocessing procedures.

Lactic acid bacteria (LAB) are essential dairy starter cultures that are significantly employed for the manufacture of fermented dairy products such as ...

Our protocol is significant because ensures purity as a quality control check. It's also promotes severe fermentation performance and consistency of yield in lactic acid bacteria fermentation. The main advantage of this technique is that it can enhance the fermentation performance of lactic acid bacteria via cell purity, viability, and functionality.This technique is user-friendly and can be easily performed by any person due to the use of only basic equipment without many technical requirements. Philip Yeboah is our graduate research assistant and he will demonstrate the procedure. To begin, take the prepared glycerol stock of lactic acid bacteria, or LAB strains, in two milliliters centrifuge tubes from the minus 80 degree Celsius ultralow freezer.Do not allow them to thaw before use. Clean and disinfect the opening of the centrifuge tubes with 70%alcohol and gently vortex before use. Pipette about 250 microliters of the stock LAB culture from the centrifuge tubes to fresh two milliliter MRS test tubes.Gently vortex the test tubes, parafilm them, and anaerobically incubate them overnight at 42 degrees Celsius for 12 to 16 hours. Next, take about 500 microliters from the overnight grown cultures from the two milliliter MRS test tubes to fresh seven milliliter MRS test tubes, vortex them, and anaerobically incubate them overnight at 42 degrees Celsius for 12 to 16 hours. Assess the microbial growth by measuring the optical density or growth of the cultures at 610 nanometers with a UV visible spectrophotometer and record acceptable results between 0.7 and 0.9.Streak the overnight cultures from the seven milliliter MRS tubes onto MRS and MRCMPYR agar plates and incubate them anaerobically for 72 hours at 42 degrees Celsius. Pick the isolated colonies from the agar plates, transfer them into fresh seven milliliter MRS test tubes, gently vortex, and anaerobically incubate them overnight at 42 degrees Celsius for 12 to 16 hours. Store the agar plates containing the isolated strains at four degrees Celsius in the refrigerator for a week.Next, measure and confirm the optical density from the seven milliliter MRS test tubes of the LAB cultures isolated from the streaked plates at 610 nanometers and use them as working cultures for all related experiments. Use nine milliliters of peptone water to perform tenfold pollutions of the grown LAB cultures from the final seven milliliter MRS test tubes to obtain a 1 to 10 ratio. Take about 250 microliters from the appropriate serial delusions for all fermentation experiments and activate the broth containing the strains by transferring them into fresh seven milliliter MRS broth and incubating them anaerobically at 42 degrees Celsius for 16 hours.Repeat the steps to ensure viable and superior cell growth from LAB cultures. Cell morphology growth of S9 and LB6 lactobacillus bulgaricus strains cultivated with the quality control protocol and S9 lactobacillus bulgaricus strains cultivated without the quality control protocol are shown here. The strains were streaked in triplicates and were anaerobically incubated at 42 degrees Celsius for 72 hours.When attempting this procedure, make sure to disinfect the stock culture tubes from the freezer with 70%alcohol to prevent cross-contamination. Optical density measurement of growth cultures should always be between 0.7 and 0.9. Following this protocol, efficient LAB fermentations or bioprocessing operations with superior use of culture can be achieved.

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Optimizing Spray-Dried Probiotic Product Quality Through Process Development

Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality

Author Spotlight: Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality  

Probiotics and prebiotics are of great interest to the food and pharmaceutical industries due to their health benefits. Probiotics are live bacteria that ...