Consortium Culture Research Articles

Development of bacterial bioformulations using response surface methodology.

Bacterial consortia exhibiting plant growth promoting properties have emerged as a sustainable approach for crop improvement. As the main challenge associated with them is viability loss and performance under natural conditions, a robust approach for designing bioformulation is needed. In this study, an efficient bioformulation was developed using spontaneous mutants of three bacterial strains for growth promotion of Cajanus cajan. Optimization of additives for solid [carboxymethylcellulose (CMC), and glycerol) and liquid [polysorbate, CMC, and polyvinyl pyrrolidone (PVP)] bioformulations was done by Response Surface Methodology using Central Composite Design. The stability of each bioinoculant in the formulation was assessed at 30°C and 4°C. The efficiency of the liquid bioformulation was checked in planta in sterile, and subsequently in non-sterile, soil. The maximum cell count was observed in solid bioformulation with 0.1g L-1 CMC and 50% glycerol (8.10×108, 3.69×108, and 7.39×108 for Priestia megaterium, Azotobacter chroococcum, and Pseudomonas sp. SK3, respectively) and in liquid bioformulation comprising 1% PVP, 0.1g L-1 CMC, and 0.025% polysorbate (8×109, 3.8×109, and 6.82×109 for Priestia megaterium, Azotobacter chroococcum, and Pseudomonas sp. SK3, respectively). The bioinoculants showed a higher viability (6 months) at 4°C compared to 30°C. Triple culture consortia enhanced plant growth in comparison to the control. The strains could be detected in soil till 45 days after sowing. The study established a systematic process for developing a potent bioformulation to promote agricultural sustainability. Using mutant strains, the bioinoculants could be tracked. In planta assays revealed that the triple culture consortium out-performed mono and dual cultures in terms of impact on plant growth.

FTIR Characterization of Bioactive Functional Groups Present in Crude Extract of Mycoherbicides Produced from Consortium Culture of Rhizosphere Fungal Isolates

ABSTRACT Consortium culture can be a relatively cheap and environment-friendly technology for producing secondary metabolites like pesticides (herbicides). This study produced some metabolites from a consortium culture of fungal isolates obtained from the rhizospheres of Panicum maximum, Ipomoea involucrata and Amaranthus viridis. The isolates from rhizospheres of the above-named plants were co-cultured using Czapek broth and were incubated in an incubator shaker for 28 days. The co-culture combinations were: Aspergillus welwitschiae and Trichoderma hamatum (consortium 1), Aspergillus welwitschiae and Aspergillus aculeatus (consortium 2), and Aspergillus aculeatus and Trichoderma hamatum (consortium 3). Crude extracts from each consortium were characterized using Fourier Transform Infrared Spectroscopy (FTIR). The FTIR results showed that consortium 1 had peak spectra range from 418.57 cm−1 (S–S stretch of aryl disulfides) to 3462.34 cm−1 (alcohol, aliphatic primary amine), consortium 2 had peak spectra range from 420.5 cm−1 (halo compound) to 3456.65 cm−1 (alcohol, aliphatic primary amine) and consortium 3 had peak spectra from 457.14 cm−1 (halo compound) to 3448.84 cm−1 (alcohol, aliphatic primary amine). Some of the compounds produced by the consortia were pesticidal in nature and are hence, considered a potential technology in developing organic pesticides.

Optimization of the production of Exopolysaccharide (EPS) from biofilm-forming bacterial consortium using different parameters

Bacterial cells produce a variety of exopolysaccharide (EPS) throughout their life cycle. EPS plays a crucial role in the formation of biofilms and the control of environmental processes in microbial communities. The bacterial community benefits from biofilms in several ways, including nutrient compartmentation and storage, environmental stress resistance and synergism. The generation of EPS by consortium-associated bacteria, which involves a variety of microorganisms, is versatile and efficient for use in industrial and environmental processes, such as biotechnology and pollution degradation. The qualitative and quantitative chemical characteristics of the consortium's EPS are mostly determined by the type of culture utilized, nutrient type, temperature, and pH. The main goal of the study was to find out how EPS biosynthesis works in a bacterial consortium culture. To achieve maximum EPS regeneration, pH, temperature, carbon, and nitrogen sources were optimized. A consortium of three bacterial strains i.e. Klebsiella pneumonia strain, Pseudomonas aeruginosa strain and Burkholderia cepacian strain that were distinguished by their capacity to produce biofilms were developed as part of the study. The maximum total EPS production was detected after 8 days of incubation at pH 7.5 (15.5 g/L) and a temperature of 35 °C (12.60 g/L). The optimum EPS production was identified as 17.84 g/L and 21.07 g/L when ammonium sulfate and glucose were employed as nitrogen and carbon supplements, respectively. The protein concentration of the EPS was 3067 µg/mL, which was more than the carbohydrate (263.10 µg/mL) and DNA (7.60 µg/mL) content. The total protein/carbohydrate ratio of the EPS detected in the present study was 11.65, which was much higher than in prior investigations. FTIR analysis of EPS confirmed the functional groups of carbohydrates, proteins, lipids and DNA, viz., CO, COOH, NH, OH, CH and OCH3. The study's findings revealed that enhancing the consortium's EPS molecules involves lowering biofilm-related infections and improving the efficacy of antimicrobial treatments in wastewater.

Home Sweet Home: Setting the Best Thriving Conditions for the Ad Hoc Engineered Microbial Consortium in the Zero Mile System

Wastewaters from household appliances, such as dishwashers and washing machines, are an untapped resource of recoverable water and/or nutrients. The Zero Mile system has been developed to reuse/upcycle dishwasher wastewaters through bioremediation activity carried out by an ad hoc engineered phototrophic/heterotrophic microbial consortium. The choice of both suitable microorganisms for engineering consortia and detailed knowledge on their structure, behaviour and interaction are essential to optimising consortium culture conditions and drive the biofilter container design (structure and topology). To these aims, the effect of abiotic conditions (i.e., irradiance, pH and organic load) on the microbial consortium growth and its capability to survive and thrive in different dishwasher wastewater dilutions have been evaluated. At the same time, the crucial interplay between biological and design research has allowed us to define the characteristics of the biofilter container and plan its development for the industrial application of the Zero Mile system, bringing sustainability benefits as it moves household wastewater from a traditional linear model to a more sustainable, circular approach.

Bacterial Consortium-Mediated Hydrocarbon Degradation of Waste Engine Oils

The automotive and industrial activities are considered one of the important sources of pollution with the increasing amount of WEO released to the environment. One of the ways to solve this problem is through bioremediation. It is, however, challenging since used engine oil contains complex hydrocarbon compounds and is toxic towards the environment and living organisms. Biodegradation by single species bacterium is limited to a small range of hydrocarbon compounds. Hence, a better strategy is to use a synergistic action of different microbial members in a consortium. Different waste engine oils from the motorcycle workshop (MW), urban vehicle workshop (UVW), and heavy vehicle workshop (HVW) were tested for degradation by a bacterial consortium culture. A two-level factorial design experiment was carried out to evaluate the effect of different WEO and nitrogen concentrations towards the growth of the bacterial culture and hydrocarbon degradation in shake flask fermentation. The bacterial consortium culture grown in mineral salts medium (MSM) supplemented with MW (Viscosity, 82 mPa.s) was shown to exhibit the highest biomass with 0.37 (OD600) with 8% (v/v) WEO and 5 g/L nitrogen from ammonium chloride (NH4Cl). Pareto chart of biomass with WEO and nitrogen concentration showed a positive effect for MW and UVW, while a negative effect for HVW which was presumed due to the toxicity, higher complexity of hydrocarbon composition and higher viscosity of WEO from heavy vehicles. Subsequently, GC-MS analysis indicated the degradation of various polyaromatic hydrocarbon (PAH) and BTEX compounds such as naphthalene, benzene, and toluene in the three WEO samples. Assessment of cell hydrophobicity of the culture grown on all three WEO exhibited high cell hydrophobicity, with HVW showing the highest cell hydrophobicity of 81%. This suggests that the bacterial culture altered cell hydrophobicity to facilitate hydrocarbon uptake.

Phycoremediation of heavy metals and production of biofuel from generated algal biomass: a review.

Due to human activity and natural processes, heavy metal contamination frequently affects the earth's water resources. The pollution can be categorized as resistant and persistent since it poses a significant risk to terrestrial and marine biological systems and human health. Because of this, several appeals and demands have been made worldwide to try and clean up these contaminants. Through bioremediation, algal cells are frequently employed to adsorb and eliminate heavy metals from the environment. Bioremediation is seen as a desirable strategy with few adverse effects and low cost. Activities and procedures for bioremediation involving algal cells depend on various environmental factors, including salinity, pH, temperature, the concentration of heavy metals, the amount of alga biomass, and food availability. Additionally, the effectiveness of removing heavy metals from the environment by assessing how environmental circumstances affect algal activities. The main issues discussed are (1) heavy metal pollution of water bodies, the role of algal cells in heavy metal removal, the methods by which algae cells take up and store heavy metals, and the process of turning the algae biomass produced into biofuel. (2) To overcome the environmental factors and improve heavy metals bioremediation, many strategies are applied, such as immobilizing the cells, consortium culture, and using dry mass rather than living cells. (3) The processes for converting produced algal biomass into biofuels like biodiesel and biomethanol. The present study discusses the life cycle assessment and the limitations of biofuel products from algae biomass.

Optimisation of Bioflocculation Using Anabaena sp. and Navicula sp. for Harvesting of Glagah Microalgae Consortium

One of the problems in microalgae is harvesting. Currently, many chemical methods are used that impact the environment. Not all of them can be used as a filter, so bioflocculation is used because there is no need to change the medium. This method is an environmentally friendly and efficient alternative to chemical flocculants that usually cause contamination of biomass and health. Previous studies have shown that different ratios of auto-flocculated microalgae in cocultures affect the flocculation rate. This research was carried out by the Glagah Consortium bioflocculation using Anabaena sp. and Navicula sp., which had never been done before. The study aims to study the effect of the mixing ratio on the flocculation rate, carbohydrates, and lipid content of the Glagah Consortium. The consortium uses Anabaena sp. and Navicula sp. as bioflocculants. Glagah and Anabaena sp. consortium was cultured in Bold Basal Medium, while Navicula sp. was cultured in F/2 medium. Cell density was measured every 24 hr for 8 days with a hemocytometer. The cultures were harvested in the stationary phase, then mixed between non-flocculated microalgae (Glagah Consortium) and flocculated microalgae (Anabaena sp., Navicula sp.) in a ratio of 1:1, 1:0.5, and 1:0.25 for 24 hr. Bioflocculation was measured by spectrophotometer at 750 nm 0 and 24 hr after mixing. Carbohydrate levels were measured using the phenol sulfuric acid method, while lipid measurements were performed using the Bligh and Dyer method. The addition of Anabaena sp. and Navicula sp. as bioflocculant in Glagah Consortium culture results in an increase in flocculation rate with an effective ratio of 1:0.25 for Anabaena sp. (81%) and 1:1 for Navicula sp. (95%). Mixing of Anabaena sp. and Glagah Consortium results in carbon source competition, reducing carbohydrate content at higher mixing ratios (0.172, 0.364, and 0.500 mg/ml on 1, 1:0.5, and 1:0.25) while increasing lipid content as a result of lipid production in stationary phase (highest on ratio 1:1 = 0.011 mg/ml). Navicula sp. and Glagah Consortium mixture caused no significant changes to carbohydrate content but showed an increased amount of lipid at all ratios as a result of osmotic stress on Glagah Consortium from saline F/2 medium (highest on ratio 1:1 = 0.162 mg/ml).

The facilitating role of phycospheric heterotrophic bacteria in cyanobacterial phosphonate availability and Microcystis bloom maintenance

BackgroundPhosphonates are the main components in the global phosphorus redox cycle. Little is known about phosphonate metabolism in freshwater ecosystems, although rapid consumption of phosphonates has been observed frequently. Cyanobacteria are often the dominant primary producers in freshwaters; yet, only a few strains of cyanobacteria encode phosphonate-degrading (C-P lyase) gene clusters. The phycosphere is defined as the microenvironment in which extensive phytoplankton and heterotrophic bacteria interactions occur. It has been demonstrated that phytoplankton may recruit phycospheric bacteria based on their own needs. Therefore, the establishment of a phycospheric community rich in phosphonate-degrading-bacteria likely facilitates cyanobacterial proliferation, especially in waters with scarce phosphorus. We characterized the distribution of heterotrophic phosphonate-degrading bacteria in field Microcystis bloom samples and in laboratory cyanobacteria “phycospheres” by qPCR and metagenomic analyses. The role of phosphonate-degrading phycospheric bacteria in cyanobacterial proliferation was determined through coculturing of heterotrophic bacteria with an axenic Microcystis aeruginosa strain and by metatranscriptomic analysis using field Microcystis aggregate samples.ResultsAbundant bacteria that carry C-P lyase clusters were identified in plankton samples from freshwater Lakes Dianchi and Taihu during Microcystis bloom periods. Metagenomic analysis of 162 non-axenic laboratory strains of cyanobacteria (consortia cultures containing heterotrophic bacteria) showed that 20% (128/647) of high-quality bins from eighty of these consortia encode intact C-P lyase clusters, with an abundance ranging up to nearly 13%. Phycospheric bacterial phosphonate catabolism genes were expressed continually across bloom seasons, as demonstrated through metatranscriptomic analysis using sixteen field Microcystis aggregate samples. Coculturing experiments revealed that although Microcystis cultures did not catabolize methylphosphonate when axenic, they demonstrated sustained growth when cocultured with phosphonate-utilizing phycospheric bacteria in medium containing methylphosphonate as the sole source of phosphorus.ConclusionsThe recruitment of heterotrophic phosphonate-degrading phycospheric bacteria by cyanobacteria is a hedge against phosphorus scarcity by facilitating phosphonate availability. Cyanobacterial consortia are likely primary contributors to aquatic phosphonate mineralization, thereby facilitating sustained cyanobacterial growth, and even bloom maintenance, in phosphate-deficient waters.CDjGUzfe77vQSL5wxbu5DEVideo

Role of Environmental Biotechnology in Remediation of Heavy Metals by Using Fungal-Microalgal Strains

Bioremediation is a branch of biotechnology that employs the use of living organisms, like microalgae and fungi, in the removal of contaminants, pollutants, and toxins from soil, water, and other environments. The experiment was designed to evaluate the efficiency of microorganisms to remove heavy metals by using, two fungi (Aspegillus niger and Candida albicans) with two microalgae (Scenedesmus quadricauda and Tetradesmus nygaardi), in removing heavy metals from liquid media during study period (20 days). For this study, cadmium and lead were selected by different concentrations (5, 15, 35, and 50ppm) of such heavy metals. The results indicate that fungi and microalgae effectively removed a significant amount of heavy metals. With respect to Pb and Cd, the maximum removal of lead for all concentrations (5-50ppm) were, (94, 90, 86.28 and 81.6%) respectively, and maximum cadmium removal were (88, 86.66, 84.57 and 79%) recorded by consortium culture of Scenedesmus quadricauda and Tetradesmus nygaardi on day 20th of the experiment. Statistically there were significant difference (p≤0.05) between control and all treatments for both tested heavy metals.

Multivariate analysis of enriched landfill soil consortia provide insight on the community structural perturbation and functioning during low-density polyethylene degradation

Plastic-enriched sites like landfills have immense potential for discovery of microbial consortia that can efficiently degrade plastics. In this study, we used a combination of culture enrichment, high-throughput PacBio sequencing of 16 S rRNA and the ITS gene, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) to examine the compositional and diversity perturbations of bacterial and fungal consortia from landfill soils and their impact on low-density polyethylene (LDPE) film biodegradation over a 90-day period. Results showed that enrichment cultures effectively utilized LDPE as a carbon source for cellular growth, resulting in significant weight reduction (22.4% and 55.6%) in the films. SEM analysis revealed marked changes in the micrometric surface characteristics (cracks, fissures, and erosion) and biofilm formation in LDPE films. FTIR analyses suggested structural and functional group modification related to C-H (2831–2943 cm⁻¹), and CH₂ (1400 cm⁻¹) stretching, CO and CC (680–950 cm⁻¹) scission, and CO incorporation (3320–3500 cm⁻¹) into the carbon backbone, indicative of LDPE polymer biodegradation. Enrichment cultures had lower diversity and richness of microbial taxa compared to soil samples, with LDPE as a carbon source having a direct influence on the structure and functioning of the microbial consortia. A total of 26 bacterial and 12 fungal OTU exhibiting high relative abundance and significant associations (IndVal > 0.7, q < 0.05) were identified in the enrichment culture. Bacterial taxa such as unclassified Parvibaculum FJ375498, Achromobacter xylosoxidans, unclassified Chitinophagaceae PAC002331, unclassified Paludisphaera and unclassified Comamonas JX898122, and six fungal species (Galactomyces candidus, Trichosporon chiropterorum, Aspergillus fumigatus, Penicillium chalabudae, Talaromyces thailandensis, and Penicillium citreosulfuratum) were identified as the putative LDPE degraders in the enrichment microbial consortium cultures. PICRUSt2 metagenomic functional profiling of taxonomic bacterial taxa abundances in both landfill soil and enrichment microbial consortia also revealed differential enrichment of energy production, stress tolerance, surface attachment and motility pathways, and xenobiotic degrading enzymes important for biofilm formation and hydrolytic/oxidative LDPE biodegradation. The findings shed light on the composition and structural changes in landfill soil microbial consortia during enrichment with LDPE as a carbon source and suggest novel LDPE-degrading bacterial and fungal taxa that could be explored for management of polyethylene pollution.

Enhancement of Microalgal Metabolite Production through Euglena sp. Local Strain and Glagah Strain Consortia

Euglena sp. is green microalgae in an acidic environment (pH 2.5-3.5). Euglena sp. has recently been developed widely in industry because of its capability to produce lipids that can be utilized to synthesize biofuel. Microalgae is a potential source of biodiesel, especially in the form of a consortium culture. One of the microalgae consortium cultures that have been explored is the nature consortium microalgae of Glagah strain. The Glagah consortia were isolated from Lagoon in the Glagah Beach, Kulonprogo, Yogyakarta. This study aimed to determine the total production of biomass, lipids, carbohydrates, and proteins of mixed culture of Glagah strain consortium and Euglena sp. as biodiesel substrate. The biomass test was measured using the dry weigh method using a filtration vacuum pump kit, lipids were measured using the Blight Dryer method by adding chloroform and methanol as solvents, carbohydrates were measured using the Sulfur Phenol Acid method by adding Phenol and sulfuric acid (H2SO4), and proteins were measured using the Bradford method by adding SDS and Bradford’s solution. The total production and productivity of biomass, lipids, carbohydrates, and proteins showed that the mixed culture of Glagah strain consortium with Euglena sp. was higher than the Glagah strain consortium. It reached 0.410 g/L; 0.253; 0.856 g/L; and 0.623 g/L. Therefore, it could be concluded that the mixed culture of the Glagah strain consortium with Euglena sp. could increase the production of biomass, lipids, carbohydrates, and protein up to two times that of the Glagah strain consortium so that this mixed culture treatment could be used as a reference in microalgae cultivation for biodiesel.

Selection of photosynthetic microorganisms grown in artificial saline industrial effluents with liquid digestate: From screening to consortium cultures

The objective of this study was to determine the feasibility of using saline industrial streams as a culture medium to grow microalgae and cyanobacteria. Experiments were performed to determine the extent of the growth in artificial saline produced water and aquifer water supplemented with liquid digestate. Tests were performed in 96-wells microplates. Media were composed with different proportion of saline artificial produced water or aquifer water supplemented with 5% v/v liquid digestate (final concentrations: 149–195 mgN·L−1, 1.5–2.7 mgP·L−1). Media were completed to 100 % with artificial seawater, corresponding to final salinities of 40, 70 and 100 g·L−1. D. salina, N. oceanica and T. suecica showed the best growth rates. They were selected to perform mixed cultures in 80 mL tubes in the same culture media. Population evolutions were followed for 19 days. Depending on salinity and industrial effluent used, different species became predominant over the two others (N. oceanica, T. suecica and D. salina. at 40, 70 and 100 g·L−1, respectively). It appears that mixed culture is a good solution to have a biomass production during a culture process where the culture media will evolve in terms of salinity and composition.

A Sustainable Method: Production of the Fermented Rice Milk Yogurt by Using Three Efficient Lactic Acid Bacteria

Lactic acid bacteria (LAB) have long been used as starters in non-dairy cereal fermentation, as they aid in the production of products such as yoghurt and cheese. Broken rice milk is a plant-based milk alternative that is high in carbs and low in fat, providing excellent nutritional value to human users. The current study intends to ferment broken rice milk supplemented with 6% skim milk using three Lactobacillus strains for the development of yoghurt products, as well as to evaluate the growth, changes in physio-chemical properties, and sensory qualities of the yoghurt produced. Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus acidophilus, and a commercial yoghurt culture consortium fermented broken rice milk after 8 h. Rather than employing L. acidophilus or a commercial yogurt culture consortia, L. bulgarics was the most efficient starter for yoghurt manufacturing, followed by L. casei. L. bulgaricus had the highest viability counts of 8.5 Log CFU/mL, 0.18 specific growth rate, and 3.78 doubling time. Furthermore, it produces a significant reduction in pH to 4.3 and increases total titratable acidity to 0.09 percent with high overall acidity values of 1.4 mg/L of acetic and lactic acid contents. The maximum acidification rate (Vmax) was 0.2125, the maximum acidification time (Tmax) was 4 h, and the time to reach pH 4.6 (Te) was 5 to 8 h. As a result, L. bulgaricus was chosen as the most efficient isolate for the production of fermented rice milk yoghurt. More research is needed, however, to investigate the new rice-based yoghurt product’s sensory qualities as well as its toxicological effects on normal and malignant human cells.

Efficiency of probiotic culture consortium application for disinfection of dairy farm premises and prevention of mastitis in cows.

In this work, the effect of probiotics on the state of the microbial background of the livestock building, on the state of udder teats, and on the prevalence of latent mastitis was investigated. Long-term use of the consortium has bactericidal activity against all cultures studied, especially the causative agent of mastitis, Staphylococcus aureus, except Proteus mirabilis, Proteus vulgaris, and Escherichia coli. The washes from animal housings and milk samples were collected from the dairy farms "Astana-Onim" Joint Stock Company and "Rodina" Limited Liability Partnership (Kazakhstan). The cleaning solutions and probiotic agents were applied directly to the udder teats of cows before and after milking. Diagnosis of subclinical mastitis was performed using the Kenotest rapid mastitis test. Directly counting the number of somatic cells in the collected milk samples from each cow was performed on a somatic cell counter. Pathogenic microorganisms, including S. aureus bacteria (50% of samples) and bacteria of the E. coli group, Enterobacter aerogenes, and P. mirabilis (36% of samples), were detected on the udder skin and milk wipes. Using a consortium of probiotic microorganisms positively affects the mammary gland more quickly than using mastitis prevention agents alone. Probiotic use for a month resulted in a significant improvement in udder teat condition, with 60.7% of teats showing normal physiological reaction to milking, a decrease in complicated hyperkeratosis, and an increase in uncomplicated mastitis. The studies showed that in the experimental group, there was a 1.5-fold reduction in the number of cows with clinically pronounced mastitis. The experimental group showed no significant changes in the number of animals with high somatic cell levels before and after the study, while the control group without probiotics had a significant increase in diseased animals after 1 month. The use of a probiotic consortium has shown promising results in reducing the incidence of mastitis and improving milk quality in cows.

Modelling of n-Hexadecane bioremediation from soil by slurry bioreactors using artificial neural network method

Diesel oil is known to be one of the major petroleum products that can pollute water and soil. Soil pollution caused by petroleum hydrocarbons has substantially impacted the environment, especially in the Middle East. In this study, modeling and optimization of hexadecane removal from soil was performed using two pure cultures of Acinetobacter and Acromobacter and consortium culture of both bacterial species using artificial neural network (ANN) method. Then the best ANN structure was proposed based on mean square error (MSE) as well as correlation coefficient (R) for pure cultures of Acinetobacter and Acromobacter as well as their consortium. The results showed that the correlations between the actual data and the data predicted by ANN (R2) in Acromobacter, Acinetobacter and consortium of both cultures were 0.50, 0.47 and 0.63, respectively. Despite the low correlation between the experimental data and the data predicted by the ANN, the correlation coefficient and the precision of ANN for the consortium was higher. As a result, ANN had desirable precision to predict hexadecan removal by the cobsertium culture of Ochromobater and Acintobacter.

Comparative study on phycoremediation performance of three native microalgae for primary-treated municipal wastewater

The current study was aimed to investigate the performance of three native microalgae in primary-treated municipal wastewater with regard to their nutrient removal, water quality improvement for reuse, and in vivo Chl-a -based biomass production. The microalgae species belonged to three different taxonomic classes, namely blue–green blue-green algae Nostoc muscorum , diatom Navicula veneta , and green microalgae Chlorella vulgaris . The comparative phytoremediation potentials of the microalgae species and the consortium were evaluated for 7 days-exponential growth phase employed in the batch systems. The results showed that the interaction between in vivo Chl-a concentration and residual concentration of TN, TP, and COD was notable. COD, TN, and TP treatment efficiencies were in the ranges of (85.7–95.7%), (72–96.9%), and (86.07–99.8%), respectively. The final concentrations of TN, TP, and COD in effluent provided by N. veneta treatment complied with EU Directive 91/271, EU Directive COM (2018)337, and national legislation, whereas the results of C. vulgaris partially complied with these legislations. Concerning the phycoremediation efficiency and the growth characteristic of the monoculture and mixed culture of the native microalgae, it was concluded that the monocultures in most cases were superior to the consortium culture. Diatom N. veneta had the highest growth rate (0.88 ± 0.04 day −1 ), Chl-a-biomass yield (50.45 ± 1.5 mg L −1 ), and removal efficiency (96.9 % TN, 99.8 % TP, 95.7 % COD). The results also reveal that the native species effectively reduce TN, TP, and COD concentrations of wastewater, and the diatom N. veneta may be a strong novel candidate for phytoremediation systems. • Three native microalgae were tested for their removal performances of pollutants in pre-treated municipal wastewater. • In vivo Chl-a fluorescence was significantly associated with the residual concentration of TN, TP, and COD. • Diatom Navicula veneta is a novel candidate in the sustainable bioremediation of municipal wastewater. • Phycoremediated municipal wastewater by diatom fulfilled the limit values of EU Directive 91/271 and EU COM(2018) 337.

Bioactivity of Organic Fermented Soymilk as Next-Generation Prebiotic/Probiotics Mixture

Fermented soymilk (soymilk yogurt) was made by fermenting soymilk with five probiotic bacterial strains (Lactobacillus plantarum ATCC 14917, Lactobacillus casei DSM 20011, Lactobacillus acidophilus ATCC 20552, Lactococcus thermophilus DSM 20259, and Bifidobacterium longum B41409) that were used as monocultures and combined with them as consortia cultures. Seven pathogenic strains, E. coli O157H7, S. aureus As4, S. typhimurium As3, S. shigae As2, L. monocytogenes As1, P. aeruginosa ATCC 27853, and B. cereus Dsmz 345, were used to study the antibacterial activity of fermented soymilk by agar well diffusion assay. Results indicated that Gram-negative pathogenesis was more sensitive to probiotic cultures than Gram-positive pathogenesis. E. coli O15H7, S. typhimirium As3, and Shigella shigae As2 were more sensitive to probiotic cultures, presenting inhibition zone diameters (IZA) ranging from 10 to 20 mm, 12 to 16 mm, and 10 to 16 mm, respectively. At the same time, P. aeruginosa Atcc 27853 showed the lowest (IZA), ranging from 3 mm to 8 mm. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at various concentrations of soymilk fermented by T1, T4, and T5, ranging from 0.031 mg/mL to 1 mg/mL against pathogenic bacterial strains. The sensory properties of FSM were evaluated, and sensory analysis during soymilk fermentation showed significant improvement. The effect of shelf life (storage period) on FSM quality and properties was evaluated; during shelf life (storage period), FSM saved its properties and quality after 28 days of cold storage. Finally, it was stated that the soymilk yogurt can be used as a substitute for buffalo and cow milk for therapeutic feeding in the future.

EXOPOLYSACCHARIDES CONTENT IN THE SAMPLES OF FUNCTIONAL FERMENTED MILK PRODUCTS

The article provides the results of studies on the level of exopolysaccharides synthesis in fermented milk bioproducts made using lactic acid and probiotic cultures: the samples «Bifi-mult» made with the use of four consortium cultures, included in the dry concentrated starter culture «Probylact-6» the samples «Bifitat» made with the use of two consortium cultures included in the dry concentrated starter «Probylact-2», bio sour cream samples obtained using three consortium of microorganisms for the production of starter culture for bio sour cream.

Effect of inoculant density on the growth of glagah consortium culture

The inoculant is an important factor in microalgae cultivation. The right initial density will be more efficient and minimise production costs. The Glagah consortium culture is a mixture of microalgae and bacteria isolated from the Glagah coast in Yogyakarta, Indonesia. This study aimed to determine the initial density to produce optimal growth for the Glagah consortium culture. The study used 3 initial densities: 100,000 cells ml−1, 500,000 cells ml−1 and 1,000,000 cells ml−1, with 3 replicates of each treatment. Parameters observed included specific growth rate, doubling time, biomass and productivity. The results showed significant differences in specific growth rate and doubling time between inoculant treatments. The highest growth rate and fastest doubling time were reached with 100,000 cells ml−1 although the highest cell density was reached with 1,000,000 cells ml−1. Biomass and productivity were not significantly different between treatments. The inoculant density of 100,000 cells ml−1 is considered the most efficient treatment, as compared to the other treatments it can produce similar biomass with less inoculant; it is therefore recommended for use in the cultivation of the Glagah consortium isolate.

Evaluation of Cr(VI) Reduction Using Indigenous Bacterial Consortium Isolated from a Municipal Wastewater Sludge: Batch and Kinetic Studies

Hexavalent Chromium (Cr(VI)) has long been known to be highly mobile and toxic when compared with the other stable oxidation state, Cr(III). Cr(VI)-soluble environmental pollutants have been detected in soils and water bodies receiving industrial and agricultural waste. The reduction of Cr(VI) by microbial organisms is considered to be an environmentally compatible, less expensive and sustainable remediation alternative when compared to conventional treatment methods, such as chemical neutralization and chemical precipitation of Cr. This study aims to isolate and identify the composition of the microbial consortium culture isolated from waste activated sludge and digested sludge from a local wastewater treatment plant receiving high loads of Cr(VI) from an abandoned chrome foundry in Brits (North Waste Province, South Africa). Furthermore, the Cr(VI) reduction capability and efficiency by the isolated bacteria were investigated under a range of operational conditions, i.e., pH, temperature and Cr(VI) loading. The culture showed great efficiency in reduction capability, with 100% removal in less than 4 h at a nominal loading concentration of 50 mg Cr(VI)/L. The culture showed resilience by achieving total removal at concentrations as high as 400 mg Cr(VI)/L. The consortia exhibited considerable Cr(VI) removal efficiency in the pH range from 2 to 11, with 100% removal being achieved at a pH value of 7 at a 37 ± 1 °C incubation temperature. The time course reduction data fitted well on both first and second-order exponential rate equation yielding first-order rate constants in the range 0.615 to 0.011 h−1 and second order rate constants 0.0532 to 5 × 10−5 L·mg−1·h−1 for Cr(VI) concentration of 50–400 mg/L. This study demonstrated the bacterial consortium from municipal wastewater sludge has a high tolerance and reduction ability over a wide range of experimental conditions. Thus, show promise that bacteria could be used for hexavalent chromium remediate in contaminated sites.