Bioremediation Agents Research Articles

A Two-Way Street: How Are Yeasts Impacted by Pesticides and How Can They Help Solve Agrochemical Contamination Problems?

Plant-associated yeasts play significant ecological roles within the microbiomes of soils and pollinating insects. In previous studies, we have shown that yeasts can assist pollinators in locating nectar, which is crucial for their nutrition and the reproduction of many angiosperms. Additionally, in soil, yeasts can also act as plant growth promoters. Given the importance of yeasts for plant development, this review first explores the biochemical processes underlying the ecological role of these microorganisms in soil, insects, and in direct association with plants. Based on this premise, we discuss the influence of these relationships on agricultural production, the biological mechanisms through which pesticides negatively affect yeast cells, and how these microorganisms can tolerate widely used agrochemicals. Finally, we address key studies in the literature that support the potential of these microorganisms as bioremediation agents. In this context, we emphasize different experiences with both indigenous and genetically engineered yeasts, which may display enzymes in their surfaces that convert pesticides into less harmful or nontoxic molecules. Our review indicates that yeasts can be effectively harnessed in organic agriculture to promote plant growth and bioremediate contaminated soil or food.

Effective Microorganisms (EM) as Bioremediation Agent of Profenofos Pesticide Residue in Vegetable Farm Soil from Benguet Province, Philippines

Effective Microorganisms (EM) as Bioremediation Agent of Profenofos Pesticide Residue in Vegetable Farm Soil from Benguet Province, Philippines

From Killer to Solution: Evaluating Bioremediation Strategies on Microbial Diversity in Crude Oil-Contaminated Soil over Three to Six Months in Port Harcourt, Nigeria

The study aimed to evaluate the efficacy of various bioremediation approaches on microbial diversity in crude oil-contaminated soil over three to six months in Port Harcourt, Nigeria. The objective was to assess the impact of different bioremediation strategies on microbial populations, particularly focusing on hydrocarbon-utilizing bacteria and fungi. Microbial populations were quantified using serial dilution and microbial count techniques. The vapor phase transfer mechanism was employed to estimate hydrocarbon-utilizing bacteria and fungi. Bacterial and fungal colonies were incubated for five days, followed by biochemical tests for isolate identification. Fungal pure cultures were observed under a microscope. The study observed a significant increase in microbial populations in soil free of crude oil pollution when bioremediators such as mushrooms and earthworms were introduced. Mushrooms exhibited a 50% increase in hydrocarbon-utilizing bacteria (HUB), while earthworms showed a 55% increase in HUB over the three to six-month period. The longer lifespan and nutrient absorption capabilities of earthworms facilitated faster growth. Furthermore, significant growth in the microbial population of hydrocarbon-utilizing bacteria and fungi was observed in crude oil-polluted soil after employing bioremediation, with the highest growth observed in soil treated with mushrooms at six months, followed by earthworms at six months. Conversely, the lowest microbial population was recorded in soil polluted with 10% crude oil and remediated with earthworms at three months. The results suggest that mushrooms and earthworms effectively increase microbial populations in crude oil-polluted soil. However, mushrooms demonstrated a higher microbial population increase compared to earthworms, especially in terms of promoting the growth of hydrocarbon-utilizing bacteria (HUB) and hydrocarbon-utilizing fungi (HUF). Based on the findings, it is recommended to prioritize using mushrooms as bioremediation agents in similar environmental restoration efforts due to their superior efficacy in increasing microbial populations, particularly HUB and HUF. This study underscores the potential of mushrooms and earthworms as effective bioremediation agents for restoring microbial diversity in crude oil-contaminated soil, offering insights for sustainable environmental restoration practices in oil-affected regions like Port Harcourt, Nigeria.

Fungi as important agents in water bioremediation

Fungi as important agents in water bioremediation

Mycosynthesis of TiO2 nanoparticles using Aspergillus penicillioides for toxic metal removal and photocatalytic applications

Globally, heavy metal pollution, especially lead and nickel, is becoming a problem and is of great concern due to its adverse effects. This study focuses on the eco-friendly biosynthesis of TiO2 nanoparticles using Aspergillus penicillioides metabolites as capping and reducing agents. The myco-synthesized TiO2 nanoparticles were characterized as oblate spherical and applied for photocatalytic removal of lead and nickel from industrial effluent. Optimal conditions for removal included lead and nickel concentrations of 60 μg/mL and 2 μg/mL, 10 μg/mL TiO2 nanoparticle concentration, a pH of 6, and sunlight irradiation. The kinetics and isotherm of adsorption were explained. Effective degradation of lead and nickel by using TiO2 nanoparticles was confirmed by atomic absorption spectroscopy. The nanoparticles demonstrated effective photocatalytic degradation of crystal violet dye achieved a high of 86.9% in 4h and 25% in 2 h, respectively, and showed promising biological activities, including antibacterial, antioxidant, and protein leakage properties. The hemolytic assay confirmed their ecological sustainability for bioremediation. The study highlights the effectiveness of new bio-based TiO2 nanoparticles arbitrated by Aspergillus penicillioides as effective bioremediation agents.

Techno-economic analysis of biocrude, biogas, and fertilizer production from microalgae Coelastrella striolata cultivated in agroindustrial wastewater

Coelastrella microalgae have gained attention due to their robustness, high lipid content, effective bioremediation agent, and ability to thrive in diverse environmental conditions. The objective of this study was to evaluate the economic feasibility of an integrated biorefinery of the unique original Coelastrella striolata var. multistriata strain 047 applied in agro-industrial wastewater, flue gases, and excess energy on a 1.2 ha open raceway pond (ORP). This study consists of three scenarios: (1) biocrude only (BO); (2) biocrude and biogas (BB); and (3) biocrude, biogas, and fertilizer (BBF). The findings indicated that the BB and BBF scenarios enhanced the financial feasibility and potential profitability of investment. This is reflected in the economic feasibility indicators for the BB scenario over a project lifetime of 20 years, which include a net present value (NPV) of $4,757,082, an internal rate of return (IRR) of 25.6%, a profitability index (PI) of 2.77, and a payback period of 3.75 years. Similarly, in the BBF scenario, financial viability is demonstrated with an NPV of $4,714,418, an IRR of 25.2%, a PI of 2.73, and a payback period of 3.79 years. Operational expenditures were identified as the most sensitive aspect of this study, particularly in the hydrothermal liquefaction (HTL) process for biocrude production. The utilization of effluent and excess energy from palm oil mill (POM) reduced the operational costs for energy and nutrients by up to 69% compared to the baseline, where palm oil mill effluent (POME) and excess energy were not utilized. Additionally, to achieve optimal results in the BO scenario, increasing the concentration of Coelastrella striolata var. multistriata strain 047 in POME proved to be the most effective approach for increasing biocrude oil production, reducing costs, and increasing economic sustainability.

Phycoremediation of Domestic Waste Water and Biodiesel Extraction from Fresh-Water Microalgae

ABSTRACT: Microalgae have recently drawn attention as a potential source for the sustainable production of biotechnologically valuable resources and improving the environment in various ways. They are widely distributed and can thrive even under extreme circumstances like high temperatures or high salinity. However, producing microalgae takes a lot of nutrients, which may have an adverse impact on the environment and the economy. The use of wastewater, particularly those from agro-industrial facilities, domestic waste waters, and industrial discharges, which often contain high nutrient concentrations, can serve as an alternative to synthetic culture media. Because the composition of wastewater and usual culture media is relatively similar, wastewater can be utilized to both clean itself and culture microalgae at the same time. Utilizing microalgae as wastewater bioremediation agents can efficiently remove N and P from domestic wastewater, maintain dissolved oxygen concentration, and reduce the various disease-causing pathogens and fecal bacteria that are present in domestic wastewater. The potential of microalgae to be used as a feedstock is increased by their ability to change the composition of their biomass under stress and accumulate lipids or carbohydrates that might be used to produce biodiesel. Methyl or ethyl esters of fatty acids produced from triglycerides by transesterification process by using renewable feedstocks are known as biodiesel. The microalgal biomass is considered as the next generation of feedstock for biofuel production. The Dual function of microalgae in domestic wastewater treatment and biomass growth for biodiesel production is outlined and discussed in detail in this review paper.

Soil Actinobacteria Exhibit Metabolic Capabilities for Degrading the Toxic and Persistent Herbicide Metribuzin.

Metribuzin, a widely used triazine herbicide, persists in agricultural soils and poses significant environmental pollution threats globally. The aim of this study was to investigate the biodegradation of metribuzin by actinobacterial strains in vitro at different environmental conditions. From an initial screen of 12 actinobacterial strains, four bacteria exhibited robust growth in the presence of the metribuzin as the sole carbon source at 50 mg/L concentration. The optimization of metribuzin biodegradation under different conditions (pH, temperature and inoculum size) using a spectrophotometric method revealed that maximum degradation of metribuzin occurred at a pH of 7.2, a temperature 30 °C, and at an inoculum volume of 4%. Subsequent GC-MS validation confirmed the remarkable biodegradation capabilities of the actinobacterial isolates, where the strain C1 showed the highest rate of metribuzin degradation of 83.12%. Detailed phylogenetic identified the active strains as Streptomyces toxytricini (CH), Streptomyces stelliscabiei (B2), and two Streptomyces heliomycini (C1, C3). Structural analysis by ATR-FTIR spectroscopy confirmed the extensive biotransformation of the herbicide molecule. Our findings highlight the immense untapped potential of soil actinobacteria, particularly the Streptomyces heliomycini C1 strain, as versatile bioremediation agents for removing persistent agrochemical pollutants.

Insights into the natural and cultural history of Typha orientalis (Raupō) in Aotearoa New Zealand

A new multi-proxy paleo database for lake ecosystem and catchment change in Aotearoa New Zealand points to the potential resource and ecosystem service roles of Typha orientalis (raupō). In the context of chronic wetland degradation in Aotearoa New Zealand over the past century, this iconic yet enigmatic wetland plant can be viewed, alternately, as an invasive threat; a valuable cultural and economic resource; and a natural, indigenous agent for bioremediation. Our investigation reconstructs the history of raupō over the past ~1000 years, based on 92 new pollen records generated from lake sites across Aotearoa New Zealand. At almost every site where raupō is present today, its expansion is promoted to varying extents during periods of human activity and at 87% of sites investigated, raupō shows its maximum palynological abundance post human arrival. Multiple patterns of response over time point to a range of hydrological, trophic, and cultural scenarios that are conducive for raupō expansion, raising prospects for its potential role in mitigating the ecological impacts of disturbance. Raupō expansion, promoted by anthropogenic forest clearances and associated sediment and nutrient flux, would in turn have provided new opportunities for its use as a valuable food and material resource, prompting further questions as to the extent it was deliberately managed by indigenous populations. As both a benefactor from, and provider for, expanding populations, raupō may be regarded as a human associate in Aotearoa New Zealand prehistory. As well as being indigenous to Aotearoa New Zealand, T. orientalis also occurs naturally in Australia and east Asia and shares the intrinsic ecological and morphological attributes of the ~40 species or hybrids of Typha that span most of the planet. This work therefore may encourage wider application of the genus as a biocultural asset informed from its local natural history.

Simultaneous nutrition removal and high-efficiency biomass accumulation by microalgae using cattle wastewater

The development of the livestock industry has led to the discharge of large quantities of nutrient-rich livestock wastewater, posing a significant challenge to wastewater treatment. Improper treatment may pose potential threats to the environment and human health. Microalgae are of great interest due to their rich nutritional value and as potential agents for bioremediation of pollution in aquatic environments. In this study, mixture of 60 % cattle wastewater (CW) and 40 % BG-11, supplemented with equal parts glucose and sodium bicarbonate, was found to be optimal for high production of Chlorella sorokiniana. Under these conditions, the highest biomass, protein, lipid concentration of C. sorokiniana were 8.98×1010 cells/L, 11.82 g/L, 24.9 %, respectively, Whereas, the removal efficiencies of total nitrogen (TN), ammonia nitrogen, total phosphorus (TP), and chemical oxygen demand (COD) were 61.44 %, 98.99 %, 89.33 % and 65.81 %, respectively. These findings highlight the potential of C. sorokiniana in simultaneous CW treatment and nutritious microalgal biomass production.

Mercury Reduction using Isolates of Indigenous Fungi with Qualitative and Quantitative Methods

Abstract Illegal gold extraction in Indonesia, particularly in Kedungbanteng, Banyumas Regency, Central Java, causes mercury pollution in rivers and poses risks to health and ecosystems. Bioremediation, using fungi, can help cleaning up mercury pollution. This is achieved through utilizing these fungi in ways that align with emerging technologies. The study used fungi isolated from gold mining sludge waste in Kedungbanteng, Banyumas Regency that have the potential to reduce mercury (Hg). Its followed by assesing the effectiveness of fungal isolates to reduce mercury (Hg) both qualitatively and quantitatively. The study found that certain indigenous fungi from the gold mine waste in Kedungbanteng, Banyumas, have the potential to reduce mercury levels. These fungi belong to the Aspergillus (isolate A2), Penicillium (isolates A1, A4, and A5), and Basidiomycota phylum (isolate A3). Isolates A3, A4, and A5 were the three most adaptable fungi in media containing high levels of Hg. Qualitative test results show isolates A3, A4, A5 formed a yellow and white precipitate. Each of them can reduce mercury levels by 46%; 32%; 48%, respectively. Isolate A3 showed the highest average reduction in mercury levels in both fungal biomass and surrounding media. The finding in this study is that there is a relationship between the results of the qualitative test and the quantitative test. The correspondence between the two types of tests shows that the qualitative test has a significant representation of the quantitative measurement of Hg values in the tested media. Penicillium sp. isolates A5 has the potential to be used as an eco-friendly bioremediation agent as the best solution to pollution. issues.

Mercury absorption using rice husk charcoal inoculated with five resistant bacteria

Abstract The use of biosorption for the rehabilitation of polluted water and soils has recently gained popularity. Biosorption is a low-risk method that immobilizes harmful compounds by employing organic waste. Mercury contamination in Indonesia requires an immediate remedy that is both inexpensive and applicable in rural regions where pollution sources are concentrated. The current study aims to investigate the usage of various organic materials, namely rice husk charcoal, compost, coco dust, and zeolite, as biosorption agents for mercury remediation through collaboration with mercury-resistant bacteria. Five previously examined bacteria strains were shown to be viable only in compost and rice husk charcoal after 30 days of observation. Further research on rice husk charcoal has shown that it might reduce mercury contamination in liquid medium with and without the inclusion of microorganisms. At 24 hours, the partnership of rice husk charcoal and mercury-resistant bacteria was shown to be more successful in absorbing the mercury by up to 66 percent. In contrast, biochar alone can only absorb mercury by up to 31 percent. This suggests that the activity of the bacteria can boost biochar’s capability to immobilize the mercury compound. Thus, the utilization of rice husk biochar amended with mercury-resistant bacteria is valuable and should be further studied as a possible mercury bioremediation agent.

Application of biohybrid membranes for arsenic and chromium removal and their impact on pollutant accumulation in soybean (Glycine max L.) seedlings.

Chromium and arsenic are among the priority pollutants to be controlled by regulatory and health agencies due to their ability to accumulate in food chains and the harmful effects on health resulting from the ingestion of food contaminated with metals and metalloids. In the present work, four biohybrid membrane systems were developed as alternatives for the removal of these pollutants, three based on polyvinyl alcohol polymeric mesh (PVA, PVA-magnetite, PVA L-cysteine) and one based on polybutylene adipate terephthalate (PBAT), all associated with bioremediation agents. The efficiency of the bioassociation process was assessed through count methods and microscopy. The removal capacity of these systems was evaluated in synthetic liquid medium, both in the absence and in the presence of soybean (Glycine max L.) seedlings. The content of chromium and arsenic was also analyzed in aerial and hypogeous tissues of seedlings grown on contaminated solid substrate. PVA and PVA-magnetite biohybrid membranes showed the highest removal rates, between 57 and 75% of the initial arsenic content and more than 80% of the initial chromium content after 48h of treatment, when evaluated in synthetic liquid media with initial concentrations of 2.5ppm of pentavalent arsenic and 5ppm of hexavalent chromium, both in presence and absence of seedlings. PVA and PBAT promoted a significant reduction of arsenic translocation to the aerial parts, generally edible, of this crop of agronomic interest. The systems tested showed a high potential for biotechnological applications in matrices affected by the presence of arsenic and chromium.

Isolation and Identification of Mercury-Resistant Fungi as Bioremediation Agents from Gold Mining

To overcome the pollution problem due to the accumulation of heavy metal Hg, a clean-up or remediation effort is needed from the former landfill for hazardous and toxic waste. In this research, bioremediation experiments will be conducted by inoculating fungi culture that is already known to have the potential to absorb heavy metals Hg. Samples of soil contaminated with heavy metals Hg taken from the tailings of gold mining owned by the people in Kertajaya Village, Simpenan District, Sukabumi Regency. The stages of this study consisted of isolation of fungi, purification and morphology of fungi isolate, screening of fungi isolate, qualitative screening of fungi for ligninolytic activity (laccase), and molecular identification of the isolated fungi. The results of the screening showed that three isolates of potential fungi coded M.2, M.10, and M.13 were able to grow with a mercury concentration of 350 ppm, while one isolate coded R4.28 reached a concentration of 1000 ppm. In addition, isolate M.2 was selected as the best strain compared to isolates M.10, M.13, and R4.28 for the qualitative test of laccase production in ligninolytic enzymes. Based on the molecular analysis of the 18S rRNA gene, M.2 isolates were similar to Trichoderma yunnanense, which was strengthened by a similarity value of 99.66%. Isolate R4.28 was similar to Penicillium soli, which was strengthened by a similarity value of 99.32%.

Hydrocarbon Degradation and Biodegraders in Oil Spillage Sites in Port Harcourt

Information on remediation of soils polluted from the activities of artisanal crude oil refining is lacking. The functional capability of the indigenous microbial community and prospects for recovery of important bio-resources has also not been explored. The aim of this study was to identify the hydrocarbon biodegrader present in oil spillage sites in Port Harcourt. Samples were taken from various sites (labelled ss1, ss2, ss3 and controls) in Port Harcourt and the samples were transported to the lab for bacteriological assessment. The samples were cultured in Nutrient agar and Basal Salt Medium (BSM). The total heterotrophic bacteria counts were enumerated by serially diluting the fluid sample. Microbial characterization was done based on morphological, physiological and biochemical tests. From the results, Pseudomonas species and Bacillus species were the probable isolated from the culture of hydrocarbon contaminated environment. The results also revealed increased compared to the control organism that maintained the same growth level throughout the 5 days of incubation, the isolated bacteria (Pseudomonas species and Bacillus species) had steady bacterial growth. This study has shown that Bacillus species and Pseudomonas aeroginosa are potential agents of bioremediation of environmental hydrocarbon pollution.

Whole genome sequencing of cr(VI) resistant Morganella morganii (1Ab1) towards identification of chromate transporters

Chromium (Cr) present naturally as the most abundant element on Earth’s crust. It usually exists combined with other chemical elements as oxygen and potassium in the form of chromium compounds. However, its level is raised due to leather tanning in tannery industries which turns less toxic trivalent chromium [Cr(III)] into highly toxic hexavalent chromium [Cr(VI)]. Chromium-resistant bacteria harbors Chr transporters in their genome which involves in metabolic reduction of toxic Cr to nontoxic Cr with the help of enzyme “chromate reductase.” This enzyme acts as a potential agent in bioremediation of highly chrome polluted sites. In this investigation, Whole Genome Sequencing (WGS) was done to find Chr transporters in the identified bacteria Morganella morganii (1Ab1) isolated from tannery effluent contaminated sites of Dindigul district, Tamil Nadu, India. Further, chr genes were confirmed using Real Time PCR and Web-based proteomic analysis tools such as Protter and Swiss Model. Finally output was reckoned for 3-D structure prediction and interactive visualization of the chr gene-encoded Chr protein that involves in Cr(VI) reduction.

Investigation of Eucalyptus camaldulensis and Tamarix aphylla species' capacities for methylene blue removal in wastewater and heavy metal remediation in soil.

In the contemporary landscape, the reuse of wastewater holds paramount significance. Concurrently, wastewater carries an array of pollutants encompassing chemical dyes and heavy metals. This study delves into the potential of Tamarix aphylla (TA) and Eucalyptus camaldulensis (EC) species for mitigating heavy metals in soil and eliminating methylene blue dye (MB) from wastewater. The research begins with assessing the dye adsorption process, considering pivotal factors such as initial pH, adsorbent dosage, initial dye concentration, and contact time. Outcomes reveal EC's superiority in dye removal compared to TA. As a bioremediation agent, EC exhibits a 90.46% removal efficacy for MB within 15 min, with pH 7.0 as the operative condition. Equilibrium analysis employs Temkin (T), Freundlich (F), and Langmuir (L) isotherms, revealing an excellent fit with the L isotherm model. The study delves further by probing surface adsorption kinetics through pseudo-first-order (PFO) and pseudo-second-order (PSO) models. Furthermore, to discern the divergent impacts of EC and TA on soil heavy metal reduction, soil samples were collected from three distinct zones: an untouched control area, alongside areas where EC and TA were cultivated at the Yazd wastewater site in Iran. Heavy metal levels in the soil were meticulously assessed through rigorous measurement and statistical scrutiny. The findings spotlight TA-cultivated soil as having the highest levels across all examined factors. Ultimately, EC emerges as the superior contender, proficiently excelling in both MB eliminations from wastewater and heavy metal amelioration in the soil, positioning it as the preferred phytoremediation agent.

Optimization of bacterial consortia for enhanced cadmium removal from contaminated environments: a case study near the Cochin Backwater System, Kerala, India

Heavy metal contamination is a major environmental and ecological threat worldwide, posing significant challenges. Excessive accumulation of heavy metal like cadmium in the environment poses significant risks to both the environment and human health, particularly in regions with industrial activities and insufficient waste management practices. In this study, we focused on optimizing bacterial consortia composed of Aeromonas hydrophila and Psychrobacter nivimaris for efficient removal of cadmium from contaminated environments, with specific emphasis on areas near the Cochin backwater system in Kerala, India. Sampling conducted at Sreebhoothapuram and Eloor Ferry Kadavu stations near Fertilizers and Chemicals Travancore (FACT) revealed these sites as having significant cadmium accumulation. Bacterial strains isolated from these stations exhibited notable resistance to cadmium, with levels reaching up to 40 mg/l and these strains maintained similar growth conditions, making them good candidates for constructing a bacterial consortium. The Cd-resistant bacteria were characterized and identified as Aeromonas hydrophila and Psychrobacter nivimaris. Through a synergetic approach, a consortium comprising two bacterial strains from different combinations obtained from these stations demonstrated promising cadmium resistance, reaching up to 60 mg/l. Mixture design optimization facilitated the determination of an optimal ratio (Aeromonas hydrophila: Psychrobacter nivimaris) = (0.329:0.671) for maximum removal efficiency. The scanning electron microscopy (SEM) analysis of both individuals and the consortium revealed morphological changes, such as modifications in the cell wall, shape, and size of the bacteria, that occur during the absorption of Cd (II). The efficiency of the optimized consortium was validated through Atomic Absorption Spectroscopy, achieving an impressive removal percentage of 96.5% for a real wastewater sample with a Relative Standard Deviation (RSD) less than 10%. This study underscores the potential of tailored bacterial consortia as effective bioremediation agents for Cd-contaminated environments, particularly in regions with elevated cadmium levels like the Cochin backwater system in Kerala.

The Ability Of Klebsiella Pneumonia And Klebsiella Oxytoca To Degrade Oil Waste

Crude oil contamination is one of the major environmental problems, it generated processing water pollution by hydrocarbon. Microorganisms have been used to remove or reduce the effects of environmental pollutants as bioremediation agents and the fact it is environmentally friendly. This study isolated two Klebsiella strains, Klebsiella pneumonia and Klebsiella oxytoca from wastewater of the North refineries company in Baiji according to the morphological and biochemical characteristics.This work aimed to evaluated the capacity of two Klebsiella strains to degrade the petroleum hydrocarbons efficacy, which excreted from wastewater of the North refineries company. The results showed that the Klebsiella oxytoca exhibited a higher hydrocarbon degradation capacity of 67.75% compared to Klebsiella pneumonia, which recorded 45.81%. While mixed culture (Klebsiella oxytoca and Klebsiella pneumonia) was recorded a biodegradation rate of 63.35%. The results showed that efficacy of Klebsiella oxytoca as biodegradation for oil wastewater was 30% higher than other strain.

Freshwater microalgae Nannochloropsis limnetica for the production of β-galactosidase from whey powder

This study investigated the first-ever reported use of freshwater Nannochloropsis for the bioremediation of dairy processing side streams and co-generation of valuable products, such as β-galactosidase enzyme. In this study, N. limnetica was found to grow rapidly on both autoclaved and non-autoclaved whey-powder media (referred to dairy processing by-product or DPBP) without the need of salinity adjustment or nutrient additions, achieving a biomass concentration of 1.05–1.36 g L−1 after 8 days. The species secreted extracellular β-galactosidase (up to 40.84 ± 0.23 U L−1) in order to hydrolyse lactose in DPBP media into monosaccharides prior to absorption into biomass, demonstrating a mixotrophic pathway for lactose assimilation. The species was highly effective as a bioremediation agent, being able to remove > 80% of total nitrogen and phosphate in the DPBP medium within two days across all cultures. Population analysis using flow cytometry and multi-channel/multi-staining methods revealed that the culture grown on non-autoclaved medium contained a high initial bacterial load, comprising both contaminating bacteria in the medium and phycosphere bacteria associated with the microalgae. In both autoclaved and non-autoclaved DPBP media, Nannochloropsis cells were able to establish a stable microalgae–bacteria interaction, suppressing bacterial takeover and emerging as dominant population (53–80% of total cells) in the cultures. The extent of microalgal dominance, however, was less prominent in the non-autoclaved media. High initial bacterial loads in these cultures had mixed effects on microalgal performance, promoting β-galactosidase synthesis on the one hand while competing for nutrients and retarding microalgal growth on the other. These results alluded to the need of effective pre-treatment step to manage bacterial population in microalgal cultures on DPBP. Overall, N. limnetica cultures displayed competitive β-galactosidase productivity and propensity for efficient nutrient removal on DPBP medium, demonstrating their promising nature for use in the valorisation of dairy side streams.