Alternative Growth Medium Research Articles

Utilization of Kluwih Seed Starch (Artocarpus camansi) as an Alternative Growth Medium for Aspergillus niger Fungus

Background: Carbohydrates in kluwih seeds have sufficient nutrients, such as potatoes and tubers, making it possible to be used as a medium for mushroom growth. The nutritional composition of breadfruit contains 25% carbohydrates, 1.5% protein, and 0.3% fat. Aspergillus niger fungi require nutrients such as carbohydrates and protein to grow. This study aims to determine whether kluwih seed starch can be used as an alternative medium for the growth of Aspergillus niger fungi. Method: This study used a pre-experimental design with laboratory observation. The study was conducted by utilizing kluwih seed starch as a medium, compared to Potato Dextrose Agar (PDA) and Sabouraud Dextrose Agar (SDA). Results: The results showed that kluwih seed starch can be used as an alternative medium for the growth of Aspergillus niger, with fungal colonies that grow macroscopically and microscopically almost the same as PDA and SDA media. Conclusion: Kluwih seed starch can be an alternative substitute for PDA media for the growth of Aspergillus niger.

Cradle-to-gate life cycle assessment of Spirulina bioplastic produced via plasticization with glycerol

Bioplastics have been used as alternatives to conventional petroleum-based plastics to lessen the burdens on marine and terrestrial environments due to their non-biodegradability and toxicity. However, recent studies have shown that not all bioplastics may be environmentally friendly. Microalgae, such as Spirulina that do not require arable land, have been identified as a potential bioplastic source. In this study, cradle-to-gate life cycle assessment (LCA) was carried out in openLCA program using the Agribalyse database, to evaluate the environmental impacts of Spirulina bioplastic, formed from plasticization of Spirulina powder with glycerol. Two processes were created for the inventories of (i) Spirulina powder and (ii) Spirulina bioplastic, where the output of the former served as an input for the latter. The extruded bioplastic sheets were food-grade and could be used as edible packaging materials. The bioplastic was also compared to conventional plastics and it was found that the energy consumption was 3.83 ± 0.26 MJ/kg-bioplastic, which was 12% and 22% higher than that of LDPE and PVC plastic films, respectively. The impacts on the environment showed that the chemical growth medium (Zarrouk medium) and electricity were the main contributors in most of the categories. Compared to the PVC and LDPE films, the Spirulina bioplastic's impacts on the aquatic ecosystems were 2–3 times higher. The global warming potential of the Spirulina bioplastic was 1.99 ± 0.014 kg CO2 eq, which was 23% and 47% lower than that of LDPE and PVC films, respectively. Sensitivity analysis was carried out by changing the electricity source and using alternative growth media. Except for the case of switching to solar energy, the results for other cases did not differ significantly from the base case scenario. Future studies were suggested to identify different greener alternatives to the growth medium as well as different energy mixes for more environmentally benign solutions.

Astaxanthin Production from Green Microalga <i>Haematococcus pluvialis</i> under Various Bean Sprout Media Concentrations and Duration of UV Radiations

Astaxanthin (AX) is known as a very strong antioxidant and has been utilised in many kinds of products such as foods, pharmaceutical, cosmetics, aquaculture, etc. One of the natural resources of AX is Haematococcus pluvialis which has been investigated by some researchers in order to enhance the AX production. However, the production of AX from the microalgae is still costly, hence, this present research is proposing low-cost methods namely bean sprout media (BSM) as an alternative growth media and UV radiation. The variations of BSM concentrations (2, 4, and 6 %) and times of UV radiation (1.5 and 3 hrs) were treated to H. pluvialis in laboratory conditions. BSM 4 % treatment showed an optimum growth of the microalga at 427 x 104 cell/ml (day 8) which also exhibited macrozooid, palmella, and aplanosore phases. UV radiation for 3 hr revealed that the concentration of AX production was as much as 17.37±0.04 mg/l. The research results were potential to be developed further in order to discover better and cheaper methods for scaling up AX production.

Filter cake extract from the beet sugar industry as an economic growth medium for the production of Spirulina platensis as a microbial cell factory for protein

BackgroundBeet filter cake (BFC) is a by-product of sugar beet processing, which is difficult to dispose of and involves severe environmental concerns. Spirulina platensis is a microalga with a high protein content essential for human and animal nutrition. The present study aimed to utilize the beet filter cake extract (BFCE) to produce Spirulina platensis commercially. However, the cultivation of S. platensis on BFCE to produce economically single-cell protein has not been reported previously.ResultsThe batch experiment revealed the maximum dry weight at Zarrouk’s medium (0.4 g/L) followed by 0.34 g/L in the treatment of 75% BFCE. The highest protein content was 50% in Zarrouk’s medium, followed by 46.5% in 25% BFCE. However, adding a higher concentration of 100% BFCE led to a protein content of 31.1%. In the adaption experiment, S platensis showed an increase in dry cell weight and protein content from 25 to 75% BFCE (0.69 g/L to 1.12 g/L and 47.0% to 52.54%, respectively) with an insignificant variation compared to Zarrouk’s medium (p ≤ 0.05), indicating that S. platensis can be economically produced when cultivated on 75% BFCE The predicated parameters from response surface methodology were NaNO3 (2.5 g/L), NaHCO3 (0.67 g/L), BFCE (33%) and pH = 8, which resulted in biomass yield and protein content (0.56 g/L and 52.5%, respectively) closer to that achieved using the standard Zarrouk’s medium (0.6 g/L and 55.11%). Moreover, the total essential amino acid content was slightly higher in the optimized medium (38.73%) than SZM (36.98%).ConclusionsTherefore, BFCE supplemented medium could be used as a novel low-cost alternative growth medium for producing a single-cell protein with acceptable quantity and quality compared to the standard Zarrouk’s medium.Graphical

Assessment of bio-based hydrogel as an alternative growth medium for seed germination and seedling growth in urban farming

Assessment of bio-based hydrogel as an alternative growth medium for seed germination and seedling growth in urban farming

Synthesis of bacterial cellulose by Komagataeibacter rhaeticus MSCL 1463 on whey.

Production costs of bacterial cellulose (BC) can be reduced using alternative fermentation media, e. g., various agricultural by-products including whey. This study focuses on whey as an alternative growth medium for BC production by Komagataeibacter rhaeticus MSCL 1463. It was shown that the highest BC production on whey was 1.95 ± 0.15g/L, which is approximately 40-50% lower that BC production on standard HS media with glucose. It was also confirmed that K.rhaeticus MSCL 1463 can utilise both lactose and galactose as the sole C source in the modified HS medium. Different whey pre-treatment methods showed that the highest BC synthesis with K.rhaeticus MSCL 1463 was achieved in undiluted whey after standard pre-treatment procedure. Moreover, BC yield from substrate on whey was significantly higher (34.33 ± 1.21%) compared to the HS medium (16.56 ± 0.64%), which shows that whey can be used as a potential fermentation medium for BC production.

Techno-economic assessment of DHA-rich Aurantiochytrium sp. production using food industry by-products and waste streams as alternative growth media

Reducing the production cost of DHA algae oil is a necessary step to obtain a sustainable omega-3 source able to compete with fish oil. In this study, a techno-economic analysis was carried out for the production of a DHA rich thraustochytrid using food industry by products and waste. Three cultivation scenarios were developed: the first using standard bulk materials as source of nutrients, the second with the utilization of brewery by-product and spent osmotic solutions; the third scenario using a mix of dairy wastewater, brewery by-product and spent osmotic solution. The operating costs were reduced by an average of 35% with food wastes scenarios, increasing up to 8% the return on investment respect to the standard cultivation method. Depending from plant dimension, sensitivity analysis showed a decrease in unit production cost up to 38% when using food industry side-streams.

Utilization of foliar fertilizer as an alternative medium for enlargement of Vanda orchid plantlets before acclimatization

This study aims to obtain an appropriate and inexpensive alternative media combination for the growth of Vanda hybrid orchids prior to acclimatization. Experiment using Factorial Randomized Block Design. The first factor is the type of media (Vacin -Went and foliar fertilizer ) and the second factor is the addition of organic matter (coconut water composition, sweet corn composition, tomato composition, BAP, NAA and without organic matter or PGR). The results showed that the interaction of treatment on plant height was only seen at 18 weeks after treatment, while the number of leaves could be seen earlier at 16 weeks after treatment. The independent effect of organic matter and PGR on the number of leaves has been seen since the age of the plant 10 weeks after treatment, while the plant height was only seen 16 weeks after treatment. Independent treatment of growing media had no effect on height and number of leaves up to 18 weeks after planting. The use of foliar fertilizer media with the type of organic material composition being tested can be suggested as an alternative growth medium for plantlet growth, not significantly different from vacin-went with BAP media.

Sustainable Cultivation of Desmodesmus armatus SAG276.4d using Leachate as a Growth Supplement for Simultaneous Biomass Production and CO2 Fixation

Microalgae cultivation has been identified to be highly beneficial for the production of valuable biomass. The recent worldwide interest is to cultivate microalgae in wastewater to replace the use of expensive commercial media. Microalgae can utilize nutrients from the wastewater for their biomass growth, which is useful as feedstock in many products. Interestingly, microalgae cultivation is also capable of reducing a greenhouse gas due to absorption of carbon dioxide (CO2) during photosynthesis. This study was conducted to study the growth of microalgae using leachate as a nutrient supplement. The scope of the research involved the cultivation of freshwater microalgae, Desmodesmus armatus, in the synthetics medium with various percentages of leachate under different light exposures. The growth parameters such as the specific growth rate, biomass productivity, and cell division time were used to evaluate the microalgae growth performance. The amount of CO2 absorbed during the cultivation was determined based on the total biomass production. The highest growth rate of 0.423/day was achieved using a 5% leachate medium under 12 h light duration, and the highest carbon fixation of 1.317 g CO2/L/day was calculated using a culture supplemented with 5% leachate with 24 h light period. The high presence of nutrients in the leachate has contributed to the growth of the microalgae; thus, it has great potential as an alternative growth medium to support biomass production and subsequently help to mitigate global warming.

The Potential of Tofu Liquid Waste and Rice Washing Wastewater as Cheap Growth Media for Trichoderma sp.

The tofu processing industry in Indonesia is massively increasing. The increasing activity of tofu production causes the disposal of tofu industrial waste to the environment to be higher as well. This condition is exacerbated by the fact that generally, the tofu industry producers do not have their appropriate tofu waste management system. The liquid waste generated from the tofu processing industry will be discharged directly into the waterways. Additionally, people in Indonesia generally use rice as their staple food. The rice washing process produces washing wastewater which is usually discharged into the environment directly. The disposal of these wastes raises the environmental pollution rate. Also, the tofu liquid waste and rice washing water contain some nutrients such as proteins, fats, carbohydrates, and vitamins. The presence of these nutrients will increase the population of pathogenic microbes in the environment. Thus, in this study, the authors discussed the potential of tofu wastewater and rice washing wastewater as alternative media for the growth of Trichoderma sp. Trichoderma sp. is an antagonistic fungus that can be used as a biocontrol agent for farmers. The use of waste as an alternative medium reduces the mass production and propagation cost of biological agents. In this study, this isolate was cultivated in tofu liquid waste and rice washing wastewater by adding a carbon source. Based on the research conducted, it was known that the average conidial density of Trichoderma sp. cultivated in tofu liquid waste was 2.9 x 106, while the conidial density of Trichoderma sp. cultivated in alternative rice washing wastewater was only 1.6 x 106. The growth of this isolate in tofu liquid waste was higher than rice washing water. It indicated that tofu liquid waste potentially to be used as a cheap alternative growth medium for Trichoderma sp.

English

The prospects for using Moringa oleifera leaves extract (MLE) supplemented with different concentrations of kanwa or sodium bicarbonate (NaHCO3) as a low-cost alternative growth medium of Spirulina platensis were evaluated in a small-scale outdoor cultivation system. The present study was aimed to evaluate the potential of MLE growth medium enriched with different concentrations (4 or 8 g L-1) of kanwa and NaHCO3 on growth, chlorophyll content, biochemical characteristics, antioxidant compounds and some physico-chemical factors. Jourdan’s standard medium was taken as control. The results showed that the growth parameters such as cell population, biomass dry weight, cell productivity and specific growth rate were positively affected in MLE cultivation medium enriched with kanwa or NaHCO3 at different concentration levels. The addition of urea, kanwa or NaHCO3 in MLE cultivation medium at different concentration levels increased significantly (p< 0.05) the protein content, the peroxidase and polyphenol oxidase activity, the conductivity, pH, total dissolved solids and salinity from 20 to 25 days of cultivation whereas a decrease in carbohydrate and phenol content was recorded during all the period of the experimentation. The highest values of growth parameters were notably in MLE medium supplemented with urea and kanwa at 8 g L-1. The MLE medium enriched with urea and kanwa at 8 g L-1 was shown to be an appropriate growth medium that can be used as a low-cost alternative growth medium for commercial cultivation of S. platensis.   Key words: Antioxidant compounds, biochemical traits, growth, Moringa oleifera leaves extract, physico-chemical factors, Spirulina platensis.

The Density and Viability of Metarhizium anisopliae Conidia on Several Growth Media

Metarhizium anisopliae is a parasitic fungus on insects, and thus called entomopathogenic fungus. This fungus is used as a biological control agent for insect pests. Fungal propagation can be done using a variety of media. The purpose of this study was to analyze the growth of M. anisopliae on four types of media, with conidial density and viability as the growth parameters. This research was conducted at the Laboratory of Microbiology, Universitas Negeri Semarang. This study was an experimental research used a Completely Randomized Design (CRD) with one factor and four treatments: Control (PDA/Potato Dextrose Agar medium), Treatment I (ELSA/Extract Larvae Sucrose Agar medium), Treatment II (CWSA/Coconut Water Sucrose Agar medium), Treatment III (CWELSA/Coconut Water and Extract Larvae Sucrose Agar medium). The and results showed that there was an effect of growth media on the density and viability of M. anisopliae conidia. CWELSA media had the highest conidial density (2.91 x 108 cfu/mL) and viability (97.17%). CWSA media had 2.82 x 108 cfu/mL and 95.33%. PDA media had 2.25 x 108 cfu/mL and 92.83%. ELSA media had 1.64 x 108 cfu/mL and 90.83%. The high conidial density and viability of M. anisopliae is CWELSA medium. This study is as an alternative growth medium to improve the quality of M. anisopliae propagation.

OPTIMIZATION of a NEW MEDIUM of WHEY WATER and SWEET POTATO EXTRACT for DIFFERENT LACTOBACILLUS SPECIES by PLACKETT-BURMAN STATISTICAL DESIGN USING MINI –TAB16 SOFTWARE

An attempt is made to use cheese whey water (Ww) and sweet potato extract (SPE) separately or in combination to manipulate a cheap and economical media component for large scale production of lactobacilli. Primarily, lactobacilli species were cultivated on de-Man Rogosa and Sharp medium (MRS) then, these strains were grown in (SPE) and (Ww) using a flask fermentation technique at 37°C, followed by applying a statistical experimental design (Plackett- Burman (PB)) via a statistical software MiniTab16 to optimize the media constituents for achieving a large scale production of lactobacilli; with studying the main effect of medium components referring to the most critical nutritional factors in the newly organized medium. Generally, our results indicated that both sweet potato and whey water extract (SPWE); could be used for the growth of lactobacilli instead of (MRS) medium. Further, other experiments were done to show how lactobacilli growth will be affected by pH and various types of whey; using standard plate count method. Highest counts for Lactobacillus acidophilus (2r) and Lactobacillus rhamnosus (190RZFAAU) were at pH 6 and pH 6.5 in (SPWE) medium. Depending on the above investigations; (SPWE) medium including the addition of different types; whey water can be used as an alternative growth medium for lactobacilli instead of MRS which was traditionally used for growing these kinds of Lactic acid bacteria (LAB). Additionally, findings in this study can help in cleaning our environment from the huge disposal quantities of whey resulted as byproduct from cheese industries.

Native plant diversity is a stronger driver for soil quality than inorganic amendments in semi-arid post-mining rehabilitation

Rehabilitation of mine sites in semi-arid landscapes is hindered by poor quality mine waste substrates, a byproduct of mining used as alternative growth media. Inorganic soil amendments, such as gypsum and urea, are sometimes used to improve the chemical and physical quality of mine waste substrates and increase native plant establishment. However, limited research is available regarding the medium and long-term effectiveness of these amendments in semi-arid post-mining landscapes. In this study, inorganic amendments were incorporated into two alternative mine substrates (mine waste and a topsoil:waste blend) in large 0.8 m3 above-ground mesocosms in the semi-arid Pilbara region of Western Australia. These mesocosms were bare soil or seeded with one of two different mixes of plant species to determine how amendments and species diversity altered plant growth and survival, and substrate quality compared to stockpiled topsoil over a 21-month period. The unamended waste had a lower electrical conductivity (EC), soil carbon (C), soil nitrogen (N) and C/N ratio compared to the topsoil. The amendments had a strong initial effect on soil quality, increasing N, soil EC and N-mineralisation in the amended waste compared to all other soil treatments. However, N levels returned to non-amended levels after the first year and the amendments had limited influence on plant growth. Plant survival was higher in the amended substrates with the more diverse plant community, which increased substrate microbial activity to levels significantly greater than the unamended waste. The use of inorganic amendments may be ineffective at increasing long-term substrate quality and growth of native plants but may support seedling survival that in turn will improve soil chemical and biological properties of waste substrates.

Pemanfaatan Biji Mangga Arum Manis (Mangifera indica L.) Sebagai Media Alternatif Pertumbuhan Candida albicans dan Aspergillus sp

Non-synthetic media is an alternative medium that utilizes ingredients found in nature. The chemical content of these ingredients is not known in detail but can be used because they are abundant in nature, easy to prepare and inexpensive. Several research results used alternative media from natural ingredients such as cassava starch for the growth of Aspergillus niger and Fusarium oxysporum , cowpeas, green beans, black soybeans, and soybean, ganyong, gembili and arrowroot , cereals, and beans . Purpose This study was to determine the seeds of mango arum sweth (Mangifera indica L.) can be used as an alternative growth medium for Candida albicans and Aspergillus sp. This research was conducted using an in vitro laboratory experimental method. The results showed that the medium mango seed (Mangifera indica L.) which had an average number of Candida albicans colonies was 1.12 x 106 cfu / ml while the medium mango seed arum sweet (Mangifera indica L.) in 72 hours incubation, the best diameter was obtained, namely 35 mm So it can be concluded that mango seed media (Mangifera indica L.) can be used as an alternative growth medium for Candida albicans and Aspergillus sp.

Air Limbah Budidaya Lele dengan Total Dissolved Solid (TDS) berbeda untuk Media Budidaya Daphnia sp


 Catfish farming waste contains a lot of organic materials which also contain phytoplankton. One of the organic materials is in the form of dissolved solids / Total Dissolved Solid (TDS). The content of TDS and Phytoplankton can be used as an alternative growth medium for Daphnia sp. Daphnia sp. is a type of cladocera for fish natural food. Catfish culture waste produces different TDS values ​​depending on the cultivation method and the food given to catfish. This study tested catfish culture waste containing different TDS for Daphnia sp. Treatment Media of catfish culture wastewater with 4 treatments of TDS value of 33, 66, 84 and 110 ppm with 3 replications. Daphnia with a density of 20 individuals / L was reared in an aquarium size 60x30x35 cm filled with 50 L of well water with a TDS content of 100 ppm. Treatment of feeding catfish culture wastewater at a dose of 0.5 L per day. Daphnia sp. and 3.5 L of sifon once a week. Water quality tests (DO, pH, temperature, TDS) were carried out every day as secondary data. The results of the analysis of the growth statistical test of Daphnia sp. showed no significant difference. This means that aquaculture wastewater with TDS values ​​of 33 ppm, 66 ppm, 84 ppm, and 110 ppm results in the growth of Daphnia sp. which is just as good. This is because the phytoplankton that grow in wastewater with TDS values ​​of 33, 66, 84, 110 ppm can meet the feed needs of Daphnia sp. during cultivation. From the results of the water quality test the DO and pH values ​​during the study were in good standard conditions for cultivation. The TDS that was observed every day for one week increased this was due to the dissolved solids content of Daphnia sp. The temperature observed during the study fluctuated very large, where at night the temperature was 20 0C while during the day it was 27.5 0C. This drastic temperature fluctuation led to the proliferation of Daphnia sp. not maximal.

Production of bacterial cellulose from whey-current state and prospects.

Bacterial cellulose (BC) is a biopolymer with a wide range of potential applications starting from the food industry and biomedicine to electronics and cosmetics. Despite that, BC industrial production to date still is associated with certain difficulties. One of them is the high cost of growth media, which can reach up to 30% of production costs. To decrease production costs, use of industrial and agricultural by-products, including whey, as alternative growth media has been reported. Whey, as the main high-volume by-product of dairy industry, which is known for its low valorisation opportunities and negative environmental impact, can nevertheless be considered as an alternative growth medium for BC production. To date, several studies aimed at evaluating BC production on whey and lactose substrates have been reported, but they are still insufficient. Reviews of them showed that, in general, BC production on untreated whey- and lactose-containing media was lower than that on the standard medium. However, some wild and recombinant strains have been reported to produce BC on whey as good as the standard medium. Enzymatic and acidic pre-treatment of whey significantly enhanced BC yield. Changes in the microstructure of BC obtained from whey were also recognised, which should be considered regarding the impact on physical properties of the desired BC product. This mini-review indicates that currently whey can be recognised as quite a problematic alternative growth substrate for industrial BC production; however, further extensive studies may improve the prospects in both the search for a cheap alternative growth substrate for industrial BC production and valorisation of whey. KEY POINTS: • Whey is a by-product in which valorisation is still challenging. • Whey can be used for bacterial cellulose (BC) production. • BC yield and properties vary upon cultivation conditions and producer strains.

Corn Wastes and Peanut Shell as Growing Media for Production of Red Radish Plants in Soilless System

ABSTRACT Peat is considered the conventional growing medium in most soilless culture systems. The high cost of peat and the urgent need of agricultural wastes recycling encouraged the scientists and soilless culture users to search for an alternative growth medium where optimal growth conditions are achieved and help in the safe disposal of wastes. In the current study, peanut shell (PS) and corn wastes (CW) were used as growing media in comparison to peat moss (PM). The tested organic wastes and peat moss were examined with sand at three mixing ratios (1:1 “M1”, 1:2 “M2” and 1:3 “M3” raw material: washed sand, respectively). Red radish (Raphanus raphanistrum subsp. sativus) plant were cultivated in 5 kg pots filled with the instigated growing media. Most of the recoded growth parameters were found in PS and PM growing media, while the lowest ones were found in CW. PS medium contained available N and P higher by 141 and 29% above the PM media. Although the peat moss gave the highest values in the measured growth characteristics, its high price decreased the net profit. The highest net profit value was obtained from PSM2 followed by PSM1 and PSM3. According to the obtained results, the characteristics of the growth media derived from peanut shell qualify them for use in the production of red radish in soilless culture systems.

Genetic and Chemical Screening in Human Blood Serum Reveals Unique Antibacterial Targets and Compounds against Klebsiella pneumoniae

Antibiotics halt the growth of bacteria by targeting core, essential physiology that is required for life on standard microbiological media. Many more biochemical and virulence processes, however, are required for bacteria to cause infection in a host. Indeed, chemical inhibitors of the latter processes are overlooked using conventional antibiotic drug discovery approaches. Here, we use human blood serum as an alternative growth medium to explore new targets and compounds. High-throughput screening of genetic and chemical libraries identified compounds targeting biological activities required by Klebsiella pneumoniae to grow in serum, such as nucleobase biosynthesis and iron acquisition, and showed that serum can chemically transform compounds to reveal cryptic antibacterial activity. One of these compounds, ruthenium red, was effective in a rat bloodstream infection model. Our data demonstrate that human serum is an effective tool to find new chemical matter to address the current antibiotic resistance crisis.

A modified reinforced clostridial medium for the isolation and enumeration of Lactobacillus delbrueckii ssp. bulgaricus in a mixed culture

In this study, we modified reinforced clostridial medium (RCM) to selectively enumerate and isolate Lactobacillus delbrueckii ssp. bulgaricus, a probiotic and important starter culture in the dairy industry. The disparity in the reported carbohydrate fermentation pattern of L. delbrueckii ssp. bulgaricus was used to develop a growth medium not only selective for L. delbrueckii ssp. bulgaricus but significantly inhibitory to the growth of other lactic acid bacteria. A recently modified RCM (mRCM) was optimized for this study by the addition of 0.5% fructose, 0.5% dextrose, 1% maltose, and 0.25% sodium pyruvate while replacing lactose as a carbohydrate source. The cell recovery and bacterial counts of L. delbrueckii ssp. bulgaricus in tested products (pure L. delbrueckii ssp. bulgaricus strains, starter culture, probiotic supplements, and yogurt) using our mRCM with sodium pyruvate (mRCM-PYR) were significantly higher than in the recently modified RCM and the common de Man, Rogosa, and Sharpe (MRS) culture medium. The growth of other lactic acid bacteria (Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Lactobacillus reuteri) and Bifidobacteria was retarded in this modified medium compared with their growth in MRS and mRCM. This result is a significant improvement in the enumeration and differentiation of L. delbrueckii ssp. bulgaricus in mRCM-PYR compared with the results in MRS and mRCM where the high background growth of similar species interferes with the accuracy of bacterial population counts. Our results thus suggest that mRCM-PYR could be recommended as a reliable alternative growth medium for the selective enumeration and isolation of L. delbrueckii ssp. bulgaricus in a mixed culture.